CN202495891U - Device and system for automatically searching power - Google Patents

Abstract

The utility model discloses a maximum power automatic search's device, include: a data import unit: all data of the searched solar panel power points are imported; a power determination unit: the data importing unit is connected with the data importing unit and is used for judging whether the data of the power point reaches the maximum power point in a preset time period; the power transmission unit is connected with the power judgment unit and used for searching the maximum power point of the solar panel and outputting the maximum power to the inverter; and the power searching unit is connected with the power judging unit and is used for continuously searching along with different light brightness. The utility model also discloses a system of power automatic search. The utility model discloses a search out the input to the dc-to-ac converter of the best power of solar panel electricity generation, the light energy that make full use of photoelectric generator to produce raises the efficiency.

Description

A device and system for automatic power search

technical field

The utility model relates to an inverter, in particular to a device and system for automatic power search.

Background technique

With the development of the economy and the progress of the society, people put forward higher and higher requirements for energy, and finding new energy has become an urgent task for human beings. The solar energy irradiated on the earth is very huge, and the energy irradiated on the earth in about 40 minutes Solar energy is enough for the energy consumption of human beings all over the world for one year. It can be said that solar energy is truly inexhaustible and inexhaustible energy, and solar power generation is absolutely clean and does not produce pollution, so solar power generation is known as an ideal energy source.

Obtaining electricity from solar energy requires photoelectric conversion through solar cells. It is completely different from other power generation principles in the past, and has the following characteristics: ①No risk of depletion; ②Absolutely clean (no pollution); ③Not restricted by geographical distribution of resources; ④Generation can be generated nearby where the power is used; ⑤High energy quality; ⑥It is easy for users to accept emotionally; ⑦It takes a short time to obtain energy. The disadvantages are: ① The energy distribution density of irradiation is small, that is, it will occupy a huge area; ② The energy obtained is related to the weather conditions such as four seasons, day and night, and cloudy or sunny. But in general, the flaws do not conceal the advantages. As a new energy source, solar energy has great advantages, so it has been valued by countries all over the world.

When using solar power to generate electricity, multiple photovoltaic modules are electrically connected, and the power generated by the photovoltaic modules is sent to the grid through one or more inverters.

An inverter is a device that converts direct current into alternating current. Since solar cells and storage batteries are DC power sources and the load is AC load, an inverter is essential. According to the operation mode, inverters can be divided into independent operation inverters and grid-connected inverters. Stand-alone inverters are used in stand-alone solar cell power generation systems to supply power to independent loads. Grid-connected inverters are used in grid-connected solar cell power generation systems. Inverters can be divided into square wave inverters and sine wave inverters according to the output waveform. The square wave inverter circuit is simple, the cost is low, but the harmonic component is large, and it is generally used in systems with a few hundred watts or less and low harmonic requirements. Sine wave inverters are expensive, but can be applied to various loads.

Photovoltaic power generation system is composed of solar cell phalanx, battery pack, charge and discharge controller, inverter, AC power distribution cabinet, sun tracking control system and other equipment.

Depending on the light, the input power of the solar panel varies. People are constantly looking for better ways to output the maximum power to the inverter.

Utility model content

In order to solve the above problems, an automatic search method, device and system for outputting the maximum power of the solar panel to the inverter are provided.

The utility model discloses a device for automatic power search, which comprises:

Data import unit: used to import all the data of the solar panel power point searched;

Power judging unit: connected to the data importing unit, used to judge whether the data of the power point reaches the maximum power point during the predetermined time period;

A power transmission unit, connected to the power judging unit, for searching the maximum power point of the solar panel and outputting the maximum power to the inverter;

The power searching unit is connected with the power judging unit, and is used for continuous searching according to the difference of light brightness.

In the device for automatic power search described in the present invention, all the data of the power point of the solar panel includes the voltage and current generated by the solar panel at the preset time point.

In the device for automatic power search described in the present invention, the maximum power point is a preset reference power point.

The utility model discloses a system for automatic power search, which comprises a photoelectric generator, an inverter connected to the photoelectric generator, a load and a power grid respectively connected to the inverter, and a power grid connected to the inverter The control unit connected with the photoelectric generator and the photoelectric generator, the control unit includes the above-mentioned device for automatic power search.

The utility model tracks the maximum power point in the solar panel in real time to exert the maximum efficacy of the solar panel. The higher the voltage, the maximum power output can be tracked through the maximum power, thereby improving the power generation efficiency.

Implementing a device and system for automatic power search of the utility model has the following beneficial technical effects:

It realizes that sunlight is input into the inverter in the preset maximum power mode, and fully utilizes the light energy generated by the photoelectric generator.

Description of drawings

Fig. 1 is a flow chart of a method for automatic power search according to an embodiment of the present invention;

Fig. 2 is a functional block diagram of a device for automatic power search according to an embodiment of the present invention;

Fig. 3 is a system component diagram of an automatic power search according to an embodiment of the present invention.

Detailed ways

In order to describe the technical content, structural features, achieved goals and effects of the present utility model in detail, the following will be described in detail in conjunction with the embodiments and accompanying drawings.

From common knowledge, we know that photovoltaic power generation (Solar photovoltaics (PV)) is based on the principle of photovoltaic effect, using solar cells to directly convert sunlight energy into electrical energy. Regardless of whether it is used independently or connected to the grid for power generation, the photovoltaic power generation system is mainly composed of three parts: solar panels (components), controllers and inverters. They are mainly composed of electronic components and do not involve mechanical parts. Therefore, photovoltaic power generation equipment Extremely refined, reliable, stable, long life, easy to install and maintain. Theoretically speaking, photovoltaic power generation technology can be used in any occasion that needs power, ranging from spacecraft to household power, large megawatt power stations, and small toys. Photovoltaic power can be used everywhere.

When the current intensity and voltage are constant, if there is no power point tracking, there will be many problems. The method of the utility model detects the power generation voltage of the solar panel in real time, and tracks the highest voltage and current value, so that the system can control the power with the highest efficiency. The grid-connected inverter supplies power to the grid.

Please refer to Figure 1, a method for automatic power search, including:

S1. Import all the data of the searched solar panel power point; the data of all the solar panel power point includes the voltage and current generated by the solar panel at the preset time point.

A solar panel is a photoelectric generator (PV cell), a semiconductor device whose electrical characteristics are similar to a diode. However, a PV cell is a source of electricity rather than an electrical load (as a diode is). When it is exposed to light (such as sunlight) The amount of exposure becomes a source of current.

Both light intensity and temperature affect PV cell characteristics. The current is proportional to the light intensity, and the voltage will also change with the fluctuation of the light intensity, and the voltage is more easily affected by the temperature change of the PV cell.

S2. Determine whether the power point data within the predetermined time period has reached the maximum power point; if yes, go to step S3, if not, go to step S4, and the maximum power point is the preset reference power point.

The power of a PV cell decreases as light intensity decreases and/or temperature increases. The solar inverter can obtain the maximum energy only when it works at the maximum power point output of the PV battery, and the maximum power point control loop can be used to achieve this purpose, which is also called the maximum power point tracker (Maximum Power Point Tracker, MPPT). In addition, the PV output voltage ripple at the PV module terminals must be small enough so that the PV current does not change too much when operating near the MPP.

S3. Search for the maximum power point of the solar panel and output the maximum power to the inverter;

The amplitude of the ripple voltage must be less than 8.5% of the MPP voltage to achieve 98% utilization. For example, if the MPP voltage of a PV module is 35V, in order to maintain 98% utilization, its voltage ripple amplitude should not more than 3.0V.

S4. Constantly search according to the difference of brightness.

Solar cells can operate over a wide range of voltages and currents. The MPP is determined by continuously increasing the resistive load on the irradiated battery from zero to a very high value, that is, at this irradiation intensity, the load can draw the maximum power from the battery.

Practice has proved that a high-quality monocrystalline silicon solar cell can produce an open circuit voltage of 0.6V when its temperature is 25 degrees. Under the condition of sufficient light, the battery temperature may be close to 45 degrees (even if the air temperature is 25 degrees), and the maximum power (Battery temperature is 45 degrees) It is usually generated under the condition that the voltage is 75 to 80% of the open circuit voltage, and the current is 90% of the short circuit current.

Please refer to Fig. 2, a kind of device of automatic power search, is used to realize above-mentioned method, comprises:

A data import unit 10 , a power judging unit 20 , a power delivery unit 30 , and a power search unit 40 .

Data import unit 10: for importing all data of the solar panel power point searched;

Power judging unit 20: connected to the data importing unit 10, used to judge whether the data of the power point has reached the maximum power point during the predetermined time period;

The power transmission unit 30 is connected to the power judging unit 20, and is used to search for the maximum power point of the solar panel and output the maximum power to the inverter;

The power searching unit 40 is connected with the power judging unit 20 and is used for continuous searching according to the brightness of the light.

Wherein, all the data of the power point of the solar panel includes the voltage and current generated by the solar panel at a preset time point, and the maximum power point is a preset reference power point.

Please refer to Fig. 3, a kind of system of power automatic search, comprise photovoltaic generator 100, the inverter 110 that is connected with photovoltaic generator 100, the load 120 that is connected with inverter 110 and grid 130 respectively, and inverter 110 and the control unit 135 respectively connected to the photoelectric generator 100, the control unit 135 includes the above-mentioned device for automatic power search.

The photovoltaic generator 100 can be a solar panel.

The working process of the system is as follows: when starting the system, the control unit 135 automatically tracks the maximum power point of the photoelectric generator 100, searches for the maximum power point and then inputs it to the inverter 110, converts DC to AC and then sends it to the load 120 or the grid 130.

It is tested by practice that the maximum power can be searched out in real time by the utility model, and the power generation efficiency can be increased by more than 30%.

Implementing a method, device and system for automatic power search of the utility model has the following beneficial technical effects:

Search for the best power generated by the solar panel to input to the inverter, make full use of the light energy generated by the photoelectric generator, and improve efficiency.

Embodiments of the present utility model have been described above in conjunction with the accompanying drawings, but the present utility model is not limited to the above-mentioned specific implementation, and the above-mentioned specific implementation is only illustrative, rather than restrictive. Under the enlightenment of the utility model, personnel can also make many forms without departing from the scope of protection of the purpose of the utility model and claims, and these all belong to the list of the protection scope of the utility model.

Claims (2)

1. the automatic searched devices of maximum power is characterized in that, comprising:

Data importing unit: all data of solar panels power points that are used to import search;

The power judging unit: link to each other with described data importing unit, whether the data of power points have reached maximum power point when being used to judge predetermined amount of time;

Power delivery unit links to each other with described power judging unit, is used to search for said solar panel maximum power point and exports described maximum power to inverter;

Power is searched the unit, links to each other with described power judging unit, is used for constantly searching along with the difference of brightness.

2. the maximum power system of search automatically; Comprise photocurrent generator; The inverter that links to each other with said photocurrent generator is with load and the electrical network that described inverter links to each other respectively, the control unit that links to each other with described inverter and electrical network; It is characterized in that described control unit comprises the automatic searched devices of the described a kind of power of claim 1.

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