CN121308564A - Energy storage inverters and energy storage systems - Google Patents
Energy storage inverters and energy storage systemsInfo
- Publication number
- CN121308564A CN121308564A CN202511883285.2A CN202511883285A CN121308564A CN 121308564 A CN121308564 A CN 121308564A CN 202511883285 A CN202511883285 A CN 202511883285A CN 121308564 A CN121308564 A CN 121308564A
- Authority
- CN
- China
- Prior art keywords
- power supply
- energy storage
- power
- storage inverter
- capacitor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Inverter Devices (AREA)
Abstract
The application provides an energy storage inverter and an energy storage system, and relates to the technical field of energy storage systems, wherein the energy storage inverter comprises an inverter circuit and an auxiliary power supply; the auxiliary power supply comprises a direct-current power supply, an alternating-current power supply and a high-power load power supply, wherein a first input end of the high-power load power supply is connected to a positive bus, a second input end of the high-power load power supply is connected to a negative bus, rated output power of the high-power load power supply is larger than that of the direct-current power supply, rated output power of the high-power load power supply is larger than that of the alternating-current power supply, a first capacitor and a second capacitor are connected in series between the positive bus and the negative bus, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to the high-power load power supply. The energy storage inverter and the energy storage system provided by the application are beneficial to solving the problems of unstable output of an auxiliary power supply, high difficulty in power supply design and low reliability of a power supply system.
Description
Technical Field
The application relates to the technical field of energy storage systems, in particular to an energy storage inverter and an energy storage system.
Background
An energy storage inverter (Power Conversion System, PCS, also referred to as an energy storage converter) is a core device in an energy storage system that is responsible for converting dc power in a battery system to ac power compatible with a power grid or load, or converting ac power to dc power for storage in a battery.
The energy storage inverter includes an auxiliary power supply within the interior that may be used to power the electrical loads of the PCS, such as control, protection and communication circuitry within the PCS. However, the existing auxiliary power supply has the problems of unstable output, high difficulty in power supply design and low reliability of a power supply system.
Disclosure of Invention
The application provides an energy storage inverter and an energy storage system, which are beneficial to solving the problems of unstable output of an auxiliary power supply, high difficulty in power supply design and low reliability of a power supply system.
In a first aspect, the present application provides an energy storage inverter comprising:
An inverter circuit and an auxiliary power supply;
The auxiliary power supply comprises a direct-current power supply, an alternating-current power supply and a high-power load power supply, wherein a first input end of the high-power load power supply is connected to a positive bus, and a second input end of the high-power load power supply is connected to a negative bus;
A first capacitor and a second capacitor are connected in series between the positive bus and the negative bus, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to a high-power load power supply.
In one possible implementation, the power load of the energy storage inverter includes a first power load;
when the output voltage of the direct current power supply is larger than that of the alternating current power supply, the direct current power supply supplies power to the first electric load;
when the output voltage of the alternating current power supply is larger than that of the direct current power supply, the alternating current power supply supplies power to the first electric load.
In one possible implementation, the energy storage inverter further includes a first diode and a second diode;
The first diode is connected between the direct current power supply and the first electric load, and the second diode is connected between the alternating current power supply and the first electric load;
when the direct current power supply supplies power to the first electric load, the first diode is turned on, and the second diode is turned off;
When the alternating current power supply supplies power to the first electric load, the second diode is turned on, and the first diode is turned off.
In one of the possible implementations of this method,
The positive bus is provided with a first switch which is connected with a soft start circuit in parallel, the soft start circuit comprises a soft start switch and a soft start resistor which are connected in series, the negative bus is provided with a second switch, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to a high-power load power supply source, and the process comprises the following steps:
When the energy storage inverter is stopped, the first switch, the soft start switch and the second switch are disconnected, and the first capacitor and the second capacitor discharge to the high-power load power supply.
In one possible implementation manner, when the energy storage inverter is started, the second switch and the soft start switch are closed, and if the difference between the voltages at the two ends of the first capacitor and the second capacitor and the output voltage of the direct current power supply is within a preset range, the first switch is closed, and the soft start switch is opened.
In one possible implementation manner, the energy storage inverter further comprises a discharging circuit structure connected between the positive bus and the negative bus in a bridging way, wherein the discharging circuit structure comprises a discharging resistor and a single-pole double-throw relay;
when the energy storage inverter works, the single-pole double-throw relay is switched to a normally open contact end;
when the energy storage inverter is stopped and the bus voltage is greater than a first threshold value, the single-pole double-throw relay is switched to a normally closed contact end, and the first capacitor and the second capacitor are discharged through a discharge resistor;
When the energy storage inverter is stopped and the bus voltage is larger than a second threshold and smaller than a first threshold, the single-pole double-throw relay is switched to the normally open contact end, and the first threshold is larger than the second threshold.
In one possible implementation manner, a plurality of power supply points are arranged between the direct-current power supply and the alternating-current power supply, and the power supply points are connected with the power utilization load of the energy storage inverter.
In one possible implementation, the rated output power of the dc power supply is equal to the rated output power of the ac power supply.
In one possible implementation manner, the energy storage inverter further includes a dc/dc converter and an ac/dc converter, and an output terminal of the dc power supply is connected to an input terminal of the dc/dc converter, and an output terminal of the ac power supply is connected to an input terminal of the ac/dc converter.
In one possible implementation manner, when the voltages at two ends of the first capacitor and the second capacitor are smaller than the voltage threshold, the first capacitor and the second capacitor stop discharging to the high-power load power supply.
In a second aspect, the application provides an energy storage system comprising a battery system and an energy storage inverter as in the first aspect, wherein the energy storage inverter is used for converting direct current output by the battery system into alternating current compatible with a power grid or a load, or is used for converting alternating current output by the power grid into direct current and storing the direct current into the battery system.
In one possible implementation manner, a grid-connected relay is arranged between the energy storage inverter and the power grid;
When the voltage difference between the output voltage of the energy storage inverter and the voltage of the power grid is smaller than a preset voltage difference threshold value, the phase difference between the output voltage of the energy storage inverter and the voltage of the power grid is smaller than a preset phase difference threshold value, the grid-connected relay is in attraction, and the energy storage inverter is connected with the power grid.
The beneficial effects of the application are as follows:
The application provides an energy storage inverter and an energy storage system, wherein the energy storage inverter comprises an inverter circuit and an auxiliary power supply, the auxiliary power supply comprises a direct current power supply, an alternating current power supply and a high-power load power supply, a first input end of the high-power load power supply is connected to a positive bus, a second input end of the high-power load power supply is connected to a negative bus, rated output power of the high-power load power supply is larger than rated output power of the direct current power supply, rated output power of the high-power load power supply is larger than rated output power of the alternating current power supply, a first capacitor and a second capacitor are connected in series between the positive bus and the negative bus, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to the high-power load power supply. Through with high-power load power supply independent connection to the generating line, carry out independent power supply for the inside high-power load of PCS for power dispersion distributes, has reduced auxiliary power's specification, and can not cause other output voltage fluctuation because of the power of certain output is too big in making auxiliary power's the multiplex output, influences output stability, thereby has increased the power design degree of difficulty, has reduced power supply system's reliability. Meanwhile, when the PCS is stopped, the bus capacitor can discharge to the high-power load power supply, so that the energy consumption of the bus capacitor is accelerated, and the discharge time is greatly shortened.
Drawings
Fig. 1 is a schematic diagram of a structure of an energy storage inverter in the related art;
fig. 2 is a schematic structural diagram of an energy storage inverter according to an embodiment of the present application;
Fig. 3 is a schematic diagram of another structure of an energy storage inverter according to an embodiment of the present disclosure;
fig. 4 is a schematic diagram of another structure of an energy storage inverter according to an embodiment of the present application.
Detailed Description
In the embodiment of the present application, unless otherwise specified, the character "/" indicates that the associated object is one or the relationship. For example, A/B may represent A or B. "and/or" describes an association relationship of an association object, meaning that three relationships may exist. For example, A and/or B may mean that A alone, both A and B, and B alone are present.
It should be noted that the terms "first," "second," and the like in the embodiments of the present application are used for distinguishing between description and not necessarily for indicating or implying a relative importance or number of features or characteristics in order.
In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. Furthermore, "at least one item(s)" below, or the like, refers to any combination of these items, and may include any combination of single item(s) or plural items(s). For example, at least one of A, B or C may represent A, B, C, A and B, A and C, B and C, or A, B and C. Wherein each of A, B, C may itself be an element or a collection of one or more elements.
In embodiments of the application, "exemplary," "in some embodiments," "in another embodiment," etc. are used to indicate an example, instance, or illustration. Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, the term use of an example is intended to present concepts in a concrete fashion.
"Of", "corresponding (corresponding, relevant)" and "corresponding (corresponding)" in the embodiments of the present application may be sometimes mixed, and it should be noted that the meanings to be expressed are consistent when the distinction is not emphasized. In the embodiments of the present application, communications and transmissions may sometimes be mixed, and it should be noted that, when the distinction is not emphasized, the meaning expressed is consistent. For example, a transmission may include sending and/or receiving, either nouns or verbs.
The equal to that related in the embodiment of the application can be used together with the greater than the adopted technical scheme, can also be used together with the lesser than the adopted technical scheme. It should be noted that when the combination is equal to or greater than the combination, the combination cannot be used with less than the combination, and when the combination is equal to or less than the combination, the combination cannot be used with greater than the combination.
Fig. 1 is a schematic diagram of a structure of an energy storage inverter in the related art, and as shown in fig. 1, the energy storage inverter (i.e., PCS) includes an inverter circuit and an auxiliary power supply. The inverter is used for realizing bidirectional conversion between direct current and alternating current, and the auxiliary power supply supplies power for the power utilization load of the energy storage inverter. The auxiliary power supply in fig. 1 is illustratively divided into 4 outputs to supply 4 power-consuming loads (load 1, load 2, load 3 and load 4), respectively, and illustratively, load 1 may be a control circuit, load 2 may be a driving circuit, load 3 may be a sensor (such as a voltage sensor or a current sensor or a temperature sensor), and load 4 may be a heat dissipating unit (such as a heat dissipating fan or a heat dissipating fan). The power required by different loads in the energy storage inverter is different, if the power required by the load 4 is larger than other loads, the power required by the load 4 is 150W, the total power required by other loads (the load 1, the load 2 and the load 3) is 30W, and the design specification (namely rated output power) of the auxiliary power supply is 180W. Because the output power corresponding to the load 4 is too large, other output voltage fluctuation of the auxiliary power supply can be caused, and the stability of other multipath outputs is affected, so that the design difficulty of the power supply is increased, and the reliability of a power supply system is reduced.
Based on the problems, the embodiment of the application provides an energy storage inverter and an energy storage system, which are beneficial to solving the problems of unstable output of an auxiliary power supply, high difficulty in power supply design and low reliability of a power supply system.
The method for the energy storage inverter according to the embodiment of the present application will now be described with reference to fig. 2 to 4.
Fig. 2 is a schematic structural diagram of an energy storage inverter provided by the embodiment of the application, as shown in fig. 2, the energy storage inverter comprises an inverter circuit and an auxiliary power supply, the auxiliary power supply is used for supplying power to an electric load of the energy storage inverter, the inverter circuit is used for realizing bidirectional conversion between direct current and alternating current, the auxiliary power supply comprises a direct current power supply, an alternating current power supply and a high-power load power supply, a first input end of the high-power load power supply is connected to a positive bus, a second input end of the high-power load power supply is connected to a negative bus, rated output power of the high-power load power supply is larger than rated output power of the direct current power supply, rated output power of the high-power load power supply is larger than rated output power of the alternating current power supply, a first capacitor C1 and a second capacitor C2 are connected in series between the positive bus and the negative bus, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to the high-power load power supply.
In the case of designing the power supply, the rated output power of the auxiliary power supply means an output power which can be continuously, safely and stably supplied by the auxiliary power supply for a long period of time under predetermined conditions such as an input voltage and an ambient temperature. In the actual working process, the output power of the auxiliary power supply is dynamically determined by the total power consumption of the load connected with the auxiliary power supply, and the power consumption of different modules in the PCS under different working states is greatly different, so that the load of the auxiliary power supply is changed in real time.
The auxiliary power supply is used for supplying power to an electric load of the energy storage inverter, for example, the auxiliary power supply can supply power to a control circuit, a driving circuit, a sensor, a communication module, a heat dissipation unit (such as a heat dissipation fan, a heat dissipation fan), a display unit and the like of the energy storage inverter. The auxiliary power supply can take power from the direct current side or from the alternating current side. Thus, the auxiliary power supply includes a direct current power supply that draws power from the direct current side, and an alternating current power supply that draws power from the alternating current side.
Optionally, the direct current power supply in the embodiment of the application takes power from the battery system, and the alternating current power supply takes power from the power grid.
In the application, the auxiliary power supply further comprises a high-power load power supply, and the high-power load power supply can be arranged on the direct current side or the alternating current side to supply power to the high-power load of the PCS, such as a plurality of heat dissipation fans of the PCS. Optionally, the rated output power of the high-power load power supply is greater than 60W. When the high-power load power supply source is set to take power from the bus on the direct current side, if the energy storage inverter is stopped, the first capacitor and the second capacitor can discharge to the high-power load power supply source.
After the energy storage converter is stopped (can be normal stop, emergency stop or fault stop), the bus capacitor is required to be discharged so as to avoid electric shock danger when equipment is overhauled. Because of the existence of the large-capacity bus capacitor, the energy storage inverter is stopped and powered off until the auxiliary power supply is powered off for a long time, which is up to half an hour, and longer waiting time and safety risk are brought to equipment maintenance. In the related art, the auxiliary power supply in the power supply structure has no output power very fast, the energy on the bus capacitor can only be discharged by the discharge resistor in the discharge circuit, and the discharge speed of the bus capacitor is not too fast in consideration of the cost and the volume of the discharge resistor, and generally, the problems of slower discharge speed and longer discharge time exist within half an hour.
According to the application, the high-power load power supply is arranged to take power from the bus at the direct current side, and when the energy storage inverter is stopped, the bus capacitor can discharge to the high-power load power supply, so that the discharge speed is increased, and the discharge time is shortened. And no extra discharging circuit is needed, no hardware component is added, and no extra loss is caused to the normal operation of the circuit. Meanwhile, the working time of a high-power load is prolonged, the energy consumption of a bus capacitor is accelerated, and the discharging time is greatly shortened. For example, when the high-power load power supply supplies power to the fan or the fan, the working time of the fan or the fan can be prolonged, and the cooling effect can be improved.
Further, considering that the voltage source of the direct current side is relatively single and mainly comes from a battery, the voltage amplitude is stabilized in an expected range, the voltage source of the alternating current side is complex and has large fluctuation, the high-power load power supply is set to take power from a direct current bus, for example, the power supply of the heat dissipation fan is set to take power from the direct current bus, the high-power load power supply can work as long as the battery is electrified, the direct current bus has high voltage, the heat dissipation fan can be started immediately, the energy storage inverter power device is effectively and quickly cooled in the whole off-grid starting and running process, the heat dissipation effectiveness and the response speed are improved, and the running safety of the energy storage converter is ensured.
Optionally, there are multiple power supply points (such as V1, V2, and V3 shown in fig. 2) between the dc power supply and the ac power supply, where the power supply points are connected to the power load of the energy storage inverter, and the load of the multiple power supply points is powered by the dc power supply and/or the ac power supply. That is, a multiplexing output is included between the dc power supply and the ac power supply. Illustratively, as shown in FIG. 2, a 3-way output is included between the DC power supply and the AC power supply.
The application connects the first input end of the high-power load power supply to the positive bus and the second input end of the high-power load power supply to the negative bus, namely the high-power load power supply is separately connected to the bus. The rated output power of the high-power load power supply is greater than the rated output power of the direct-current power supply, and the rated output power of the high-power load power supply is greater than the rated output power of the alternating-current power supply, for example, the rated output power of the high-power load power supply may be 150W, and the rated output power of the direct-current power supply or the rated output power of the alternating-current power supply may be 30W. The high-power load power supply supplies power to the high-power load (load corresponding to a power supply point V4 shown in fig. 2) in the energy storage inverter independently, so that power is distributed in a scattered manner, the specifications of the direct-current power supply and the alternating-current power supply are reduced, the output of the power supply point V4 cannot influence the fluctuation of the output voltage of other power supply points (V1, V2 and V3), the stability of the output of the auxiliary power supply is improved, the design difficulty of the power supply is reduced, and the reliability of a power supply system is improved.
Alternatively, the high power load inside the energy storage inverter may be a heat radiation fan, a large-sized display unit, a wireless communication module in a transmitting state, or the like.
It can be understood that the number of the high-power load power supplies in the energy storage inverter may be one or more, and if the number of the high-power load power supplies is plural, the rated output power of the plurality of high-power load power supplies may be the same or different, and may be specifically set according to the power design requirement. Fig. 2, 3 and 4 are only illustrative of one high power load power supply.
Optionally, the rated output power of the dc power supply is equal to the rated output power of the ac power supply. When the direct current auxiliary power supply or the alternating current auxiliary power supply needs to supply power to the same load independently, such as the control circuit, the driving circuit and the protection circuit in the energy storage inverter, the direct current power supply and the alternating current power supply must be designed to provide the same output power because the total power requirement of the load is fixed, so that the stable operation of the energy storage inverter system is ensured. When the direct-current auxiliary power supply or the alternating-current auxiliary power supply needs to supply power to different loads independently, for example, the direct-current auxiliary power supply supplies power to the control circuit, the alternating-current auxiliary power supply supplies power to the driving circuit, and at the moment, the rated output power of the direct-current auxiliary power supply can be different from the rated output power of the alternating-current auxiliary power supply.
In some alternative embodiments, fig. 3 is another schematic structural diagram of an energy storage inverter according to an embodiment of the present application, where, as shown in fig. 3, the energy storage inverter further includes a DC/DC converter (i.e., a DC/DC converter) and an AC/DC converter (i.e., an AC/DC converter), an output terminal of a DC power supply is connected to an input terminal of the DC/DC converter, and an output terminal of the AC power supply is connected to an input terminal of the AC/DC converter.
The DC power supply takes power from a battery system (typically high voltage DC, such as 200V-500V) and converts the high voltage DC of the battery to various low voltage DC required by the auxiliary power supply via a DC/DC converter. When the power grid fails, the power supply source is the only power supply source, and key components such as an inverter control system, a display panel and a communication module are ensured to be uninterrupted. The alternating current power supply source takes power from the power grid side, and converts alternating current into various low-voltage direct currents required by the auxiliary power supply through an AC-DC converter.
In some alternative embodiments, the first capacitor C1 and the second capacitor C2 are stopped from discharging to the high power load power supply when the voltage across the first capacitor C1 and the second capacitor C2 is less than the voltage threshold.
In the present application, the purpose of capacitor discharge is to reduce dangerously high voltages to safe voltages (e.g., 60V and below). Therefore, when the voltages at the two ends of the first capacitor C1 and the second capacitor C2 are smaller than the voltage threshold (e.g. 60V), it is indicated that the discharging task is completed, and no discharging is needed. Therefore, when the voltage across the first capacitor C1 and the second capacitor C2 is smaller than the voltage threshold, the first capacitor C1 and the second capacitor C2 are stopped from discharging to the high-power load power supply. And the discharge is forbidden under the safety voltage, so that unnecessary risks or interference caused by false triggering during normal operation of the energy storage system can be avoided.
In some alternative embodiments, the power load of the energy storage inverter provided by the application comprises a first power load, the first power load is powered by the direct current power supply when the output voltage of the direct current power supply is greater than the output voltage of the alternating current power supply, and the first power load is powered by the alternating current power supply when the output voltage of the alternating current power supply is greater than the output voltage of the direct current power supply.
The first electric load may be any load other than a high-power load in the energy storage inverter, for example, the first electric load may be any one of a control circuit, a driving circuit, and a protection circuit.
In general, when the grid voltage is in a normal stable state, the output voltage of the ac power supply that takes power from the ac side is greater than the dc power supply that takes power from the dc side, and at this time, the power supply capability of the ac power supply is stronger than that of the dc power supply, and the ac power supply can supply power to the first load alone. When the power grid voltage is abnormal, for example, when the power grid is in low voltage ride through, the output voltage of the alternating current power supply which takes power from the alternating current side is smaller than that of the direct current power supply power which takes power from the direct current side, and at the moment, the power supply capacity of the direct current power supply power is stronger than that of the alternating current power supply, and the direct current power supply power can independently supply power to the first load. By comparing the output voltage of the direct current power supply with the output voltage of the alternating current power supply, the auxiliary power supply with large output voltage supplies power to the first load preferentially, so that the power supply reliability is ensured, and the energy storage inverter can operate stably.
In some alternative embodiments, the first electrical load is powered by the dc power supply and the ac power supply together according to a preset power supply ratio when the output voltage of the dc power supply is equal to the output voltage of the ac power supply. Alternatively, the preset power supply ratio (dc power supply: ac power supply) may be 1:1, or 3:7, or 4:6. Through common power supply, the reliability of power supply is improved, the service life of a power supply is prolonged, and the power supply mode is more flexible.
In some alternative embodiments, when the grid voltage fluctuates, the direct current power supply supplies power to the first electric load, so that the reliability of power supply and the safety of the system are ensured.
It will be appreciated that the power control logic of the ac power source and the dc power source may be controlled by a controller in the energy storage inverter.
In some optional embodiments, the energy storage inverter further comprises a first diode and a second diode, wherein the first diode is connected between the direct current power supply and the first electric load, the second diode is connected between the alternating current power supply and the first electric load, the first diode is conducted when the direct current power supply supplies power to the first electric load, the second diode is cut off, and the second diode is conducted when the alternating current power supply supplies power to the first electric load, and the first diode is cut off.
In some alternative embodiments, fig. 4 is a schematic structural diagram of an energy storage inverter according to an embodiment of the present application, and as shown in fig. 4, taking a power supply point V1 as an example, a load corresponding to the power supply point V1 is a first load, a first diode D1 is connected between a dc power supply and the first electric load, and a second diode D2 is connected between an ac power supply and the first electric load. The diode has a unidirectional conduction function, so that the diode can be used for realizing power supply control logic of an alternating current power supply and a direct current power supply. Specifically, when the direct current power supply supplies power to the first electric load, the first diode D1 is turned on, the second diode D2 is turned off, and when the alternating current power supply supplies power to the first electric load, the second diode D2 is turned on, and the first diode D1 is turned off.
In some optional embodiments, a first switch is arranged on a positive bus and connected with a soft start circuit in parallel, the soft start circuit comprises a soft start switch and a soft start resistor which are connected in series, a second switch is arranged on a negative bus, and when the energy storage inverter is stopped, a process of discharging the first capacitor and the second capacitor to a high-power load power supply comprises the steps of switching off the first switch, the soft start switch and the second switch, and discharging the first capacitor and the second capacitor through the high-power load power supply.
As shown in fig. 4, a first capacitor C1 and a second capacitor C2 are connected in series between a positive bus and a negative bus, the positive bus is provided with a first switch RLY1, the first switch RLY1 is connected in parallel with a soft start circuit, the soft start circuit comprises a soft start switch RLY3 and a soft start resistor R which are connected in series, and the negative bus is provided with a second switch RLY2. When the energy storage inverter is shut down, the first switch RLY1, the soft start switch RLY3 and the second switch RLY2 are disconnected, and the first capacitor C1 and the second capacitor C2 are discharged through the high-power load power supply. If the high-power load power supply is a fan power supply, the first capacitor C1 and the second capacitor C2 are discharged through the fan power supply, so that the fan power supply can continue to supply power to the fan, and the fan can be delayed to run for 2-3 minutes after the energy storage inverter is stopped.
In some alternative embodiments, when the energy storage inverter is started, the second switch and the soft start switch are closed, and if the difference between the voltages at the two ends of the first capacitor and the second capacitor and the output voltage of the direct current power supply is within a preset range, the first switch is closed, and the soft start switch is opened.
Specifically, when the energy storage inverter is started, the second switch RLY2 and the soft start switch RLY3 are closed, and if the difference between the voltages at the two ends of the first capacitor C1 and the second capacitor C2 and the output voltage of the dc power supply is within a preset range, the first switch RLY1 is closed, and the soft start switch RLY3 is opened. When the energy storage inverter is started, the bus voltage is stably increased through the current limiting resistor (namely the soft start resistor R), so that the current and the thermal stress on the bus capacitor are reduced, the service life of the capacitor is prolonged, and the influence of current impact generated by instantaneous starting on the normal operation of equipment is avoided.
In some embodiments, the energy storage inverter provided by the embodiment of the application further comprises a discharging circuit structure connected between the positive bus and the negative bus in a bridging way, wherein the discharging circuit structure comprises a discharging resistor and a single-pole double-throw relay;
when the energy storage inverter works, the single-pole double-throw relay is switched to a normally open contact end;
When the energy storage inverter is stopped and the bus voltage is greater than a first threshold value, the single-pole double-throw relay is switched to a normally closed contact end, and the discharge resistor is used for discharging the first capacitor and the second capacitor;
When the energy storage inverter is stopped and the bus voltage is larger than a second threshold and smaller than a first threshold, the single-pole double-throw relay is switched to the normally open contact end, and the first threshold is larger than the second threshold.
With continued reference to fig. 4, the discharging circuit structure connected across the positive bus and the negative bus comprises a discharging resistor r and a single-pole double-throw relay SPDT (Single Pole Double Throw), when the energy storage inverter is powered on and works, the single-pole double-throw relay is switched to the normally open contact end, at this time, the discharging circuit structure is disconnected and does not consume bus energy, when the energy storage inverter is stopped, the single-pole double-throw relay is switched to the normally closed contact end, and the discharging circuit structure is switched to the bus to discharge the capacitor.
Further, in the initial stage of discharge, when the bus voltage is greater than the first threshold value, the first capacitor and the second capacitor are discharged by the discharge resistor r. Meanwhile, the first capacitor and the second capacitor can also be discharged by using a high-power load power supply. And in the later stage of discharging, when the bus voltage is larger than a second threshold value and smaller than a first threshold value, the single-pole double-throw relay is switched to the normally open contact end, and at the moment, the first capacitor and the second capacitor are only discharged through the high-power load power supply.
Optionally, the first threshold is 100V and the second threshold is 60V.
In the application, when the bus voltage is greater than 100V, the discharging resistor and the high-power load power supply are used for discharging the first capacitor and the second capacitor, so that the voltage can be pulled down from high voltage (such as 400V) to a relatively safe intermediate value (such as 100V) in a short time. In the initial stage of discharge, the bus voltage is high and the energy is large, if the auxiliary power supply is used, the discharge is slow due to the limited power, and the overload damage is possible.
When the bus voltage is 60V-100V, the first capacitor and the second capacitor are discharged by using a high-power load power supply. In the low-voltage stage, the residual energy is not much, the auxiliary power supply is used for consuming the energy, the efficiency is higher, and the energy can further supply power for the high-power load, so that the energy utilization rate is improved. Meanwhile, the heat dissipation cost of the discharge resistor can be reduced.
It is understood that the first threshold and the second threshold may be set according to the actual situation of discharging the bus capacitor, which is not limited in the present application.
It should be noted that, the bus voltage refers to the voltage across the first capacitor C1 and the second capacitor C2, and may be measured by a voltage detection device (such as a voltage sensor).
It will be appreciated that the energy storage converter shown in fig. 4 may also comprise a dc/dc converter and an ac/dc converter, the output of the dc power supply being connected to the input of the dc/dc converter, the output of the ac power supply being connected to the input of the ac/dc converter.
The application provides an energy storage system which comprises a battery system and an energy storage inverter as shown in the embodiment, wherein the energy storage inverter is used for converting direct current output by the battery system into alternating current compatible with a power grid or a load or converting alternating current output by the power grid into direct current and storing the direct current into the battery system.
In one possible implementation manner, as shown in fig. 4, a grid-connected relay is arranged between the energy storage inverter and the power grid, and when the voltage difference between the output voltage of the energy storage inverter and the voltage of the power grid is smaller than a preset voltage difference threshold value, and the phase difference between the output voltage of the energy storage inverter and the voltage of the power grid is smaller than a preset phase difference threshold value, the grid-connected relay is engaged, and the energy storage inverter is connected with the power grid. The method comprises the steps of detecting voltages on two sides of a grid-connected relay, wherein the voltage difference between the output voltage of an energy storage inverter and the voltage of a power grid is smaller than a preset voltage threshold value, judging that voltage phase locking is successful when the phase difference between the output voltage of the energy storage inverter and the voltage of the power grid is smaller than a preset phase difference threshold value, and connecting the power grid by means of the suction of the grid-connected relay.
The working process of the auxiliary power supply is described in detail below, and a fan power supply is taken as an example of the high-power load power supply.
When the switch rli 2 and the switch rli 3 are closed, the soft start circuit, the bus bar and the bus bar capacitors C1 and C2 form a loop, and the soft start circuit charges the bus bar capacitors C1 and C2. When the voltages at the two ends of C1 and C2 are close to the output voltage of the direct current power supply, the switch RLY1 is closed, and the switch RLY3 is opened, so that the soft start process is completed, and a main circuit is established. And detecting the voltages at two sides of the grid-connected relay, and when the voltage phase locking is successful, the grid-connected relay is attracted and connected with a power grid.
The direct current power supply or the alternating current power supply supplies power for the power supply point under the control of the diode. Taking the power supply point V1 as an example, if the voltage value of the dc power supply is greater than the voltage value of the ac power supply, the diode D1 is turned on and the diode D2 is turned off, and the dc power supply supplies power to the power supply point V1, and if the voltage value of the dc power supply is less than the voltage value of the ac power supply, the diode D2 is turned on and the diode D1 is turned off, and the ac power supply supplies power to the power supply point V1.
When the energy storage inverter is shut down, the grid-connected relay is turned off, and the switches rli 1, rli 2 and rli 3 are turned off. The capacitors C1 and C2 discharge to the fan power supply, so that the fan power supply can continue to supply power to the fan, and the fan can be delayed to run for 2-3 minutes after the energy storage inverter is stopped.
In summary, the energy storage inverter and the energy storage system provided by the application comprise an inverter circuit and an auxiliary power supply, wherein the auxiliary power supply is used for supplying power to an electric load of the energy storage inverter, the inverter circuit is used for realizing bidirectional conversion between direct current and alternating current, the auxiliary power supply comprises a direct current power supply, an alternating current power supply and a high-power load power supply, a first input end of the high-power load power supply is connected to a positive bus, a second input end of the high-power load power supply is connected to a negative bus, rated output power of the high-power load power supply is larger than rated output power of the direct current power supply, rated output power of the high-power load power supply is larger than rated output power of the alternating current power supply, a first capacitor and a second capacitor are connected in series between the positive bus and the negative bus, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to the high-power load power supply. Through with high-power load power supply independent connection to the generating line, carry out independent power supply for the inside high-power load of PCS for power dispersion distributes, has reduced auxiliary power's specification, and can not cause other output voltage fluctuation because of the power of certain output is too big in making auxiliary power's the multiplex output, influences output stability, thereby has increased the power design degree of difficulty, has reduced power supply system's reliability. And the bus capacitor can be discharged through the high-power load power supply, so that the discharging speed of the bus capacitor is improved, and the discharging time is shortened.
The foregoing is merely exemplary embodiments of the present application, and any person skilled in the art may easily conceive of changes or substitutions within the technical scope of the present application, which should be covered by the present application. The protection scope of the present application shall be subject to the protection scope of the claims.
Claims (12)
1. An energy storage inverter, comprising:
An inverter circuit and an auxiliary power supply;
The auxiliary power supply comprises a direct-current power supply, an alternating-current power supply and a high-power load power supply, wherein a first input end of the high-power load power supply is connected to a positive bus, and a second input end of the high-power load power supply is connected to a negative bus;
And a first capacitor and a second capacitor are connected in series between the positive bus and the negative bus, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to the high-power load power supply.
2. The energy storage inverter of claim 1, wherein,
The power utilization load of the energy storage inverter comprises a first power load;
When the output voltage of the direct current power supply is larger than that of the alternating current power supply, the direct current power supply supplies power to the first electric load;
and when the output voltage of the alternating current power supply is larger than that of the direct current power supply, the alternating current power supply supplies power for the first electric load.
3. The energy storage inverter of claim 2, further comprising a first diode and a second diode;
The first diode is connected between the direct current power supply and the first electric load, and the second diode is connected between the alternating current power supply and the first electric load;
when the direct current power supply supplies power to the first electric load, the first diode is conducted, and the second diode is cut off;
When the alternating current power supply supplies power for the first electric load, the second diode is conducted, and the first diode is cut off.
4. The energy storage inverter of claim 1, wherein,
The positive bus is provided with a first switch, the first switch is connected with a soft start circuit in parallel, the soft start circuit comprises a soft start switch and a soft start resistor which are connected in series, the negative bus is provided with a second switch, and when the energy storage inverter is stopped, the first capacitor and the second capacitor discharge to the high-power load power supply, and the process comprises the following steps:
When the energy storage inverter is stopped, the first switch, the soft start switch and the second switch are disconnected, and the first capacitor and the second capacitor discharge to the high-power load power supply.
5. The energy storage inverter of claim 4, wherein,
When the energy storage inverter is started, the second switch and the soft start switch are closed, and if the difference value between the voltages at the two ends of the first capacitor and the second capacitor and the output voltage of the direct current power supply is within a preset range, the first switch is closed, and the soft start switch is opened.
6. The energy storage inverter of claim 1, further comprising a discharge circuit structure connected across the positive bus and the negative bus, the discharge circuit structure comprising a discharge resistor and a single pole double throw relay;
when the energy storage inverter works, the single-pole double-throw relay is switched to a normally open contact end;
when the energy storage inverter is stopped and the bus voltage is greater than a first threshold value, the single-pole double-throw relay is switched to a normally closed contact end, and the first capacitor and the second capacitor are discharged through the discharge resistor;
when the energy storage inverter is stopped and the bus voltage is larger than a second threshold value and smaller than the first threshold value, the single-pole double-throw relay is switched to a normally open contact end, and the first threshold value is larger than the second threshold value.
7. The energy storage inverter of claim 1, wherein,
And a plurality of power supply points are arranged between the direct current power supply and the alternating current power supply, and the power supply points are connected with a power utilization load of the energy storage inverter.
8. The energy storage inverter of claim 1, wherein,
The rated output power of the direct current power supply is equal to the rated output power of the alternating current power supply.
9. The energy storage inverter of claim 1, wherein,
The energy storage inverter further comprises a direct current/direct current converter and an alternating current/direct current converter, wherein the output end of the direct current power supply is connected with the input end of the direct current/direct current converter, and the output end of the alternating current power supply is connected with the input end of the alternating current/direct current converter.
10. The energy storage inverter of claim 1, wherein,
And stopping discharging the first capacitor and the second capacitor to the high-power load power supply when the voltage at two ends of the first capacitor and the second capacitor is smaller than a voltage threshold.
11. An energy storage system, comprising a battery system and the energy storage inverter of any one of claims 1-10, wherein the energy storage inverter is used for converting direct current output by the battery system into alternating current compatible with a power grid or a load, or is used for converting alternating current output by the power grid into direct current and storing the direct current into the battery system.
12. The energy storage system of claim 11, wherein the energy storage system comprises,
A grid-connected relay is arranged between the energy storage inverter and the power grid;
when the voltage difference between the output voltage of the energy storage inverter and the voltage of the power grid is smaller than a preset voltage difference threshold value, the phase difference between the output voltage of the energy storage inverter and the voltage of the power grid is smaller than a preset phase difference threshold value, the grid-connected relay is attracted, and the energy storage inverter is connected with the power grid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511883285.2A CN121308564A (en) | 2025-12-15 | 2025-12-15 | Energy storage inverters and energy storage systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511883285.2A CN121308564A (en) | 2025-12-15 | 2025-12-15 | Energy storage inverters and energy storage systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN121308564A true CN121308564A (en) | 2026-01-09 |
Family
ID=98292235
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202511883285.2A Pending CN121308564A (en) | 2025-12-15 | 2025-12-15 | Energy storage inverters and energy storage systems |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN121308564A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN206850512U (en) * | 2017-06-02 | 2018-01-05 | 南京南瑞继保电气有限公司 | A kind of dual input auxiliary power supply of photovoltaic inverter electric power system |
| CN112039313A (en) * | 2020-07-28 | 2020-12-04 | 漳州科华技术有限责任公司 | Auxiliary power supply device, control method of auxiliary power supply device, and converter |
| CN114629370A (en) * | 2022-03-29 | 2022-06-14 | 阳光电源股份有限公司 | Power conversion system, control method for power conversion system, and power system |
| CN117895764A (en) * | 2024-01-02 | 2024-04-16 | 阳光电源股份有限公司 | Discharge circuit of energy storage converter and control method thereof, and energy storage converter |
| CN118739873A (en) * | 2024-06-18 | 2024-10-01 | 阳光电源股份有限公司 | Inverter and control method |
| WO2025016071A1 (en) * | 2023-07-20 | 2025-01-23 | 爱士惟科技股份有限公司 | Auxiliary power supply system |
-
2025
- 2025-12-15 CN CN202511883285.2A patent/CN121308564A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN206850512U (en) * | 2017-06-02 | 2018-01-05 | 南京南瑞继保电气有限公司 | A kind of dual input auxiliary power supply of photovoltaic inverter electric power system |
| CN112039313A (en) * | 2020-07-28 | 2020-12-04 | 漳州科华技术有限责任公司 | Auxiliary power supply device, control method of auxiliary power supply device, and converter |
| CN114629370A (en) * | 2022-03-29 | 2022-06-14 | 阳光电源股份有限公司 | Power conversion system, control method for power conversion system, and power system |
| WO2025016071A1 (en) * | 2023-07-20 | 2025-01-23 | 爱士惟科技股份有限公司 | Auxiliary power supply system |
| CN117895764A (en) * | 2024-01-02 | 2024-04-16 | 阳光电源股份有限公司 | Discharge circuit of energy storage converter and control method thereof, and energy storage converter |
| CN118739873A (en) * | 2024-06-18 | 2024-10-01 | 阳光电源股份有限公司 | Inverter and control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10637283B2 (en) | Power supply system and method | |
| KR101930252B1 (en) | Device for automatically rescuing lift and saving energy and method thereof, and super-capacitor module | |
| EP2966740B1 (en) | Dc power system for marine applications | |
| JP6470003B2 (en) | Uninterruptible power supply and uninterruptible power supply system | |
| KR102234290B1 (en) | Energy storage system and controlling method the same | |
| EP2850717B1 (en) | Elevator backup power supply | |
| RU2009145271A (en) | ENERGY MANAGEMENT OF ALTERNATIVE SOURCES | |
| WO2022247412A1 (en) | Power supply system for air conditioning device, and air conditioning device and data center | |
| KR20170026695A (en) | Hybrid Energy Storage System | |
| EP4152550A1 (en) | Non-current-sharing ups apparatus, shunting method, and ups parallel connection system | |
| US9806636B2 (en) | DC/AC converter apparatus configurable as grid-connected or stand-alone and power conversion and generation system comprising such DC/AC converter apparatus | |
| CN121308564A (en) | Energy storage inverters and energy storage systems | |
| JP7470750B2 (en) | Power System | |
| JP7474063B2 (en) | Power supply system, coupling device, power supply unit and control method | |
| CN209104893U (en) | Backup power system and backup power unit | |
| CN220066969U (en) | Light storage and charging system for direct current screen | |
| CN120511825B (en) | Combined energy storage device supporting hot plug and control method | |
| KR20110004389U (en) | High Speed Swithing typed UPS | |
| CN223899003U (en) | Energy storage standby power supply device | |
| KR200301007Y1 (en) | Uninterruptible power supply | |
| CN211456775U (en) | Energy storage converter and power supply system thereof | |
| KR101288723B1 (en) | Energy storage and supply system | |
| JP7381360B2 (en) | Power system and control method | |
| CN210536348U (en) | UPS integrated system | |
| CN208368893U (en) | A kind of power distribution socket |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |