WO2006136801A2 - Ameliorations de convertisseurs electriques de puissance - Google Patents

Ameliorations de convertisseurs electriques de puissance Download PDF

Info

Publication number
WO2006136801A2
WO2006136801A2 PCT/GB2006/002239 GB2006002239W WO2006136801A2 WO 2006136801 A2 WO2006136801 A2 WO 2006136801A2 GB 2006002239 W GB2006002239 W GB 2006002239W WO 2006136801 A2 WO2006136801 A2 WO 2006136801A2
Authority
WO
WIPO (PCT)
Prior art keywords
supply
electric power
converter
pwm converter
auxiliary pwm
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.)
Ceased
Application number
PCT/GB2006/002239
Other languages
English (en)
Other versions
WO2006136801A3 (fr
Inventor
Allan David Crane
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GE Power Conversion Brazil Holdings Ltd
Original Assignee
Converteam Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Converteam Ltd filed Critical Converteam Ltd
Publication of WO2006136801A2 publication Critical patent/WO2006136801A2/fr
Publication of WO2006136801A3 publication Critical patent/WO2006136801A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
    • H02M7/02—Conversion of AC power input into DC power output without possibility of reversal
    • H02M7/04—Conversion of AC power input into DC power output without possibility of reversal by static converters
    • H02M7/12—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/217—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M7/23—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only arranged for operation in parallel
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
    • H02M7/02—Conversion of AC power input into DC power output without possibility of reversal
    • H02M7/04—Conversion of AC power input into DC power output without possibility of reversal by static converters
    • H02M7/12—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/145—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
    • H02M7/155—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only
    • H02M7/17—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only arranged for operation in parallel
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
    • H02M1/4208—Arrangements for improving power factor of AC input
    • H02M1/4283—Arrangements for improving power factor of AC input by adding a controlled rectifier in parallel to a first rectifier feeding a smoothing capacitor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the present invention broadly relates to electrical power converters for converting AC power to DC power at medium to high powers, for example, 1 Mega- Watt (MW) or more. More particularly, the invention relates to the efficient use of thyristor bridge rectifiers.
  • MW Mega- Watt
  • thyristor bridge rectifiers provide good efficiency and reliability at low cost, size and mass when used to supply DC current to a DC load.
  • their supply harmonics and power factor characteristics are not ideal.
  • such rectifiers can cause harmonic distortion at the point of common coupling with other consumers, thus possibly causing other equipment on the network to malfunction.
  • harmonic pollution may cause unwanted heating of transformers and generators in the supply network.
  • the input power factor of the rectifier is less than unity, particularly when its output DC voltage is at a low value. All of these effects dictate that the transformer or generator MVA (Mega- Volt-Amp) rating must be increased relative to an ideal MW rating.
  • MVA Mega- Volt-Amp
  • Another limitation of the thyristor supply bridge in its simple rectifying form is that it cannot be used in reverse to supply power to the supply network, in situations where the load terminal polarity must be non-reversing.
  • An object of the present invention is therefore to mitigate the above mentioned disadvantageous harmonic and power factor effects.
  • a further object is to minimise the effect of the reverse power limitation.
  • the invention secures the above objectives for electric power converters of the above type by means of a converter combination in which an auxiliary Pulse Width Modulated (PWM) converter is connected across a DC output filter of the thyristor supply bridge and connection of the auxiliary PWM converter is enabled either back to the main AC supply network to which the thyristor supply bridge is connected, or to a separate AC supply independent of the AC supply network to which the thyristor supply bridge is connected, or to a low voltage DC supply.
  • PWM Pulse Width Modulated
  • the output of a thyristor supply bridge is usually fed to a DC load via a passive DC- link filter. Accordingly, in the combination of the invention, the auxiliary PWM converter is connected across the DC link filter output terminals in parallel with the load.
  • the auxiliary PWM converter may be either a voltage source inverter or a matrix converter.
  • the auxiliary PWM converter is connected to the main AC supply network via passive components, whose purpose is to mitigate the effects of the common mode and differential mode voltage content of the PWM carrier wave.
  • passive components preferably comprise a passive filter (e.g., an L-C filter) and an isolating transformer connected in series between the auxiliary converter and the main AC supply network.
  • a dynamic braking resistor may also be associated with the input of the auxiliary PWM converter (e.g., connected across the passive filter, or even located in the main AC supply network) to selectively absorb regenerative power, selection of the dynamic braking resistor being conveniently achieved by switch means responsive to the voltage level in the main AC supply network, or to the level of regenerative power.
  • a further passive filter in the form of a capacitance may be connected to the supply network in parallel with the above-mentioned passive components.
  • the auxiliary PWM converter is arranged for connection to the separate AC supply by way of at least one passive component, this being a passive filter for connection in series between the auxiliary PWM converter and the separate AC supply.
  • the auxiliary PWM converter is arranged for connection to the low voltage DC supply by way of at least one passive component, this being a passive filter for connection in series between the auxiliary PWM converter and the low voltage DC supply.
  • the DC load applied to the DC-link filter output terminals associated with the thyristor supply bridge comprises a second voltage source inverter which has either a large number of parallel paths within it, or is outputting a larger than normal number of AC phases (e.g., to a ten-phase electric motor)
  • the design and constructional features of the second voltage source inverter may be used as the basis for the design of the auxiliary PWM converter. This has the advantage of reduced manufacturing costs due to commonality of the electronic components used.
  • the invention further embraces an electric power system comprising: (a) a main AC power supply network,
  • an electric power converter combination for converting AC power from the main AC power supply network to DC power to supply the DC load
  • the converter combination comprising a phase controlled thyristor supply bridge rectifier with a DC output filter to the DC load and an auxiliary PWM converter connected across the DC output filter, the auxiliary PWM converter also having supply input means connected to power supply means comprising either the main AC supply network, an AC supply separate from the main AC supply network, or a low voltage DC supply.
  • the invention further includes various methods of operating an electric power converter combination constructed as described above.
  • the firing pulses for switching devices in the auxiliary PWM converter are inhibited, whereby when the thyristor supply bridge rectifier and the auxiliary PWM converter are connected to the main AC supply network, all the power from the main AC supply network to the load is through the thyristor supply bridge rectifier.
  • the thyristor supply bridge draws lagging VAr' s from the main AC supply network and the auxiliary converter operates as an inverter to inject leading VAr 's into main AC the supply network, thereby to at least partially correct the effect of the lagging VAr' s drawn by the thyristor supply bridge.
  • the thyristor supply bridge draws harmonic currents from the main AC supply network and the auxiliary PWM converter operates as an inverter to inject harmonic currents into the main AC supply network in anti-phase to those drawn by the thyristor supply bridge, thereby to at least partially correct an effect of the harmonic currents drawn by the thyristor supply bridge upon the voltage drop across a supply impedance of the main AC supply network.
  • the firing pulses for switching devices in the thyristor supply bridge are inhibited and the auxiliary PWM converter operates as an inverter to inject power back into the main AC supply network.
  • the firing pulses for switching devices in the thyristor supply bridge are inhibited and the auxiliary PWM converter operates as an inverter to inject power back into a dynamic braking resistor.
  • the auxiliary PWM converter inverts while the thyristor supply bridge rectifies, thereby to avoid discontinuous conduction in the thyristor supply bridge, such that most of the power flows from the main AC supply network to the load via the thyristor supply bridge, whilst a smaller proportion of power circulates from the main AC supply network, through the thyristor supply bridge, the auxiliary converter and the common DC link filter, and back to the main AC supply network.
  • the firing pulses for switching devices in the thyristor supply bridge are inhibited and the auxiliary PWM converter operates as a PWM rectifier, whereby power flows from the main AC supply network to the load with low harmonic current distortion and with the auxiliary PWM converter controlling the supply power factor.
  • the firing pulses for switching devices in the thyristor supply bridge are inhibited and the auxiliary PWM converter is connected to the separate AC supply network, the auxiliary PWM converter operating as a PWM rectifier, whereby power flows from the separate AC supply network to the load with low harmonic current distortion and with the auxiliary PWM converter controlling the power factor.
  • the firing pulses for switching devices in the tliyristor supply bridge are inhibited and the auxiliary PWM converter is connected to the low voltage DC supply network, the auxiliary PWM converter operating as a PWM rectifier, whereby power flows from the low voltage DC supply network to the load with low impressed current distortion.
  • Figure 1 is a single-line circuit diagram showing a simple embodiment of the invention
  • Figures 2 to 10 illustrate various operating modes of the circuit arrangement of Figure l.
  • Figure 11 is a block diagram of a control system suitable for controlling operation of an electric power converter combination according to the invention in the context of a variable speed electric drive for an electric motor;
  • a three-phase AC distribution bus 1 supplies power to an AC load 2 through a converter comprising a phase controlled thyristor rectifier or supply bridge 4 and a voltage source inverter 6, the thyristor supply bridge 4 and the voltage source inverter 6 being connected by a passive DC-link filter 8, comprising in this example a capacitance 8a and an inductance 8b for each DC output terminal.
  • the passive DC-link filter 8 may be simplified to a single L- C filter.
  • the AC load 2 may be, e.g., a high power electric motor requiring a multiphase supply.
  • the inverter 6 and the AC load 2 may be collectively thought of as a DC load connected across the DC-link filter 8 of the thyristor supply bridge 4.
  • Other types of DC load may be substituted, such as: single and multiple output, direct- and transformer-coupled, DC-DC converters with step- down, step-up and step-down/step-up topologies (this latter topology being otherwise known as a Buck-Boost converter); and DC-AC derivatives.
  • the exact nature of the DC load is immaterial to the basic principle of the present invention.
  • the distribution bus 1 is a high voltage supply, e.g., 3KV or higher, the distribution voltage must be stepped down by a transformer 9 (indicated in dashed lines) because thyristor supply bridges have certain input voltage limitations.
  • an auxiliary PWM converter 10 with its own DC link filter 12, is combined with the thyristor supply bridge by connect it into the DC load circuit of the thyristor supply bridge and also into the main AC supply network 1.
  • the auxiliary converter 10 with its own DC-link 12 is connected across the output terminals of the DC link filter capacitance 8a.
  • the auxiliary PWM converter 10 is a voltage source inverter, whose AC supply side is connected to the main AC supply network 1 via passive components comprising an L-C filter 13 in series with an isolating (double- wound) transformer 14. Note that it will also be necessary to equip the connection of the auxiliary PWM converter 10 to the supply network 1 with a circuit breaker, shown simply by "X" in Figure 1.
  • the auxiliary PWM converter 10 may be either a voltage source inverter or a matrix converter.
  • auxiliary PWM converter 10 is a voltage source inverter, then it is advantageous to connect it to the supply network via the passive components comprising filter 13 and transformer 14 so as to mitigate the effects of the common mode and differential mode voltage content of the PWM carrier wave produced by the auxiliary converter.
  • a further passive filter in the form of a capacitance 16 may be connected to the supply network in parallel with the passive components 13 and 14.
  • Another capacitance filter 17 (shown in dashed lines) may be added between the isolating transformer 14 and the supply.
  • auxiliary PWM converter 10 would not need to be connected to the supply network 1 through an isolating transformer 14 and in fact it might have sufficient inherent input filter capacity to allow its direct connection to the supply network 1 without benefit of a separate passive filter. Nevertheless, in some circumstances, to prevent circulating current components flowing between the thyristor rectifier and the auxiliary PWM converter via the DC- link and the supply network terminals, it may be preferable to connect the auxiliary PWM converter 10 (being a matrix converter) to the supply network via the above- mentioned L-C passive filter 13 and in parallel with a capacitative passive filter 16.
  • auxiliary PWM converter 10 can operate in both rectifying and inverting modes, and for economy may be built from the same types of modules as the voltage source inverter 6.
  • auxiliary PWM converter 10 and the voltage source inverter 6 employ IGBTs, GTOs, or their respective derivatives, operating with either asynchronous or synchronous PWM carrier frequencies.
  • the input voltage of the auxiliary PWM converter 10 must be lower than that of the thyristor supply bridge 4 and its transformer VA rating will be much lower than the rating of the thyristor supply bridge. Consequently, an auxiliary converter with a relatively small VA rating can have a significant effect upon a system having a large VA rating.
  • the minimum VA rating for the auxiliary PWM converter as a voltage source inverter is realised when a Greatz bridge is used. An increased rating is achieved when three H bridges are employed. Further parallel-connected arms containing the auxiliary PWM converter components of Figure 1 can be employed to further increase the VA rating.
  • the supply voltage for the auxiliary PWM converter is 50-70% of that applied to the thyristor supply bridge 4.
  • the invention provides the benefits of both phase controlled thyristor and PWM equipment whilst suffering few of their disadvantages. As always, the result will be a compromise and will benefit from an optimisation process.
  • the invention can operate in a number of different modes, to give greatly enhanced flexibility of operation as a power supply.
  • a diagram illustrates the power flow in a converter supplying the DC load comprising the inverter 6 and the AC load 2.
  • the thyristor supply bridge 4 is shown as having a transformerless input, but all the operating modes are equally applicable to a transformer-fed system. Two or more operating modes can occur simultaneously, as specified below.
  • Mode 4 inherently combines the benefits of Modes 2 and 3, without suffering the disadvantage of Mode 1.
  • Mode 6 inherently combines Modes 1 and 4, and can also achieve the benefits of Modes 2 and 3.
  • Modes 5, 8 and 9 are specialised modes of operation in which the auxiliary converter 10 does not take power from, or supply power to, the main AC supply network 1.
  • This mode is illustrated in Figure 2, the power flow being through the thyristor supply bridge 4 and the voltage source converter 6 to the AC load 2, with firing pulses being inhibited for the switching devices in the auxiliary PWM converter 10 so that it merely acts as a diode rectifier.
  • the thyristor supply bridge 4 provides maximum efficiency and reliability, at lowest cost, size and mass, however, its harmonics and power factor are non-ideal, as indicated at the left of the power flow arrow.
  • the non-ideal power input conditions dictate that the generator MVA rating must be increased relative to an ideal MW rating and supply voltage distortion may be significant.
  • the thyristor supply bridge cannot sustain inversion, other than during operation with a thyristor firing delay angle sufficiently large to cause reversal of the
  • the thyristor supply bridge 4 can employ variable thyristor firing delay angle control as a means of achieving DC link voltage control, but such control worsens supply harmonics and power factor.
  • the power flows as shown by the arrows are into the load 2 from the main AC supply network 1 via the thyristor supply bridge 4 and the inverter 6 and back into the supply network 1 from the load via the inverter 6 and the auxiliary converter 10.
  • the thyristor supply bridge 4 draws lagging MVAr' s from the supply network 1 and the auxiliary converter 10 operates as an inverter to inject leading MVAr's into the supply network, so enabling partial, full, or overcorrection of the effect of the associated thyristor supply bridge 4.
  • loads causing leading or lagging power factor on the supply network 1 can be fully or partially compensated, as desired, insofar as this is within the capacity of the auxiliary converter 10 in combination with the converter 6.
  • this mode would enable a reduction in generator size, mass and cost, or increase the propulsive power available from a given generator rating.
  • Unity power factor can easily be achieved at loads below 50% power, using the minimum size auxiliary converter configuration (Greatz bridge) mentioned above. Hence, this mode is especially relevant to operation where the supply network is provided with limited generator capacity. As load is increased, power factor reduces but is still better than in existing equipment. A larger leading MVAr capacity can be provided by changing the auxiliary converter 10 to an H bridge type, or by employing parallel-connected switching arms, but this may not be the most cost effective use of such a circuit topology.
  • Mode 3 power flow from the main AC supply network 1 through the supply bridge 4 and the converter 6 is associated with reversible power flows for harmonic injection through the auxiliary converter 10, which operates in both inverting and rectifying modes to provide active filtration of the current harmonics generated by the thyristor supply bridge 4 and/or, active filtration of pre-existing voltage harmonics on the supply network 1.
  • the load 2 is an electric motor
  • Mode 3 enables reduction of generator size, mass and cost, or enables an increase in the effective power available from the supply network.
  • this mode of operation of the invention would be more competitive than a stand-alone low voltage (LV) inverter-based system, due to its integration with the load's converter power circuit 6 and controls.
  • This system would be much smaller than a competing medium voltage (MV) passive filter and the effects of supply impedance variation upon the tuning of resonant circuits would be less problematic, due to the reduction in capacitance of filters and the ability to employ active damping of reactances associated with the point of common coupling on the main AC supply network 1.
  • MV medium voltage
  • auxiliary converter 10 operates as an inverter in Mode 4 and power is fed back into the main AC supply network 1.
  • this mode is advantageous if the load 2 is an induction motor being used regeneratively as a brake and is thereby generating power, which may be fed into the network 1 to help supply other loads.
  • this operating mode does not inject significant harmonics into the supply network 1, because it inherently incorporates the function of Mode 3.
  • this operating mode does not inject significant MVAr 's into the supply network 1 because it inherently incorporates the function of Mode 2, thereby enabling control of the power factor in the supply network, say between 0.9 lagging and 0.9 leading, including unity power factor.
  • FIG. 6 This mode is shown in Figure 6 and is closely related to Mode 4 ( Figure 5), in that if the circumstances are such that one or more loads elsewhere on the main AC supply network 1 were to be taken off-line by protective devices or for some other reason, the supply network 1 might not be capable of absorbing the regenerated power from load (motor) 2, again indicated by the power flow arrow.
  • a dynamic braking resistor 20 is connected to the AC input terminals of the auxiliary PWM converter 10 to absorb motor regenerated power in the above-mentioned event of removal of load from the network.
  • the braking resistor is connected across the filter 13, but could be located within the AC supply network 1.
  • the resistor 20 is connected through a switch 21 with the aim of reducing unnecessary dissipation of power in the resistor when regenerative power is not being produced.
  • Operation of the switch can be automatic, e.g., by sensing an excessive voltage increase on the supply network 1, or by detecting production of regenerative power.
  • the auxiliary converter 10 inverts while the thyristor supply bridge 4 rectifies. Most of the power flows from the supply network 1 to the DC load (i.e., inverter 6 plus motor 2) via the more efficient thyristor supply bridge 4, but a smaller proportion of power circulates from the supply network I 5 through the thyristor supply bridge 4, the common DC link filter 8 and the auxiliary converter 10, back to the supply network.
  • the DC load i.e., inverter 6 plus motor 2
  • This circulating current mode avoids discontinuous conduction in the thyristor supply bridge 4, providing the benefits of reduced disruption of the control of the thyristors in bridge 4.
  • Such disruption results from discontinuous current through the thyristors and consequent sporadic resumption of thyristor conduction at the mid-point in each half-cycle of the thyristor supply bridge's AC line current waveform.
  • this sporadic resumption of thyristor conduction may also cause forward recovery failure of the thyristor.
  • the supply bridge DC link filter 8 ( Figure 8) must be charged to working voltage, just as is necessary for operation in Mode 1.
  • the auxiliary converter 10 operates as a rectifier, with the power flow being from the main AC supply network to the load via the auxiliary converter 10.
  • the firing pulses of the thyristor supply bridge 4 will normally be suppressed. All power flow is via the PWM bridge, with low harmonics and controllable power factor, say 0.9 lagging to 0.9 leading, including unity power factor. This enables reduction (if desired) of size, mass and cost of a generator feeding the supply network, or an increase in the effective power available from a given generator rating. This mode is especially relevant to situations where generator capacity is limited, such as on board ships or at isolated sites.
  • Mode 8 operates identically to Mode 7, except that as shown in Figure 9, a separate LV AC power supply IL is used to supply power to the load through the auxiliary converter 10, rather than the main AC supply network 1.
  • a separate LV AC power supply IL could be produced by an AC generator driven by a prime mover, such as a diesel engine or a gas turbine.
  • Figure 9 assumes a transformerless system. However, this entails the use of an additional line filter 22 to deal with the PWM carrier harmonics from the auxiliary converter 10. Such a filter 22 would probably need to be more complex than shown, comprising inductive and capacitative components, as known. Alternatively, auxiliary converter 10 could be isolated from the supply IL by inserting a transformer between the supply IL and the L-C filter 13, as in Mode 7. In fact, strict quality of power supply requirements for an LV AC supply would make such transformer- isolation highly desirable. MODE 9 - OPERATION FROM LV DC SUPPLY
  • This mode of operation is similar to Mode 8, except that the separate LV power supply is a DC source, such as a battery 30, a fuel cell or a DC generator driven by a prime mover. It will be apparent that the use of a DC/AC converter to supply AC power to the auxiliary converter 10 would detract from this arrangement's simplicity and introduce inefficiencies. Hence, the insertion of an isolating transformer between the DC supply line and the filter 13 is not an advantageous modification and therefore an additional line filter 22 ' will be required, similar to the filter 22 in Figure 10.
  • FIG 11 shows simplified control systems for both the thyristor supply bridge 4 and the auxiliary PWM converter 10, the latter being employed in accordance with the invention to enhance the performance of the known thyristor supply bridge.
  • the control scheme for the thyristor supply bridge 4 is of a generally known type, in which a current transducer 36 on the AC input line to the thyristor supply bridge 4 provides a current feedback signal 33 to a current regulator 32.
  • the thyristor supply bridge 4 is regulated thereby so as to satisfy the overall requirements of a set of functions in the Variable Speed Drive (VSD) regulator 40, these functions being represented by the current regulator reference signal 37.
  • VSD Variable Speed Drive
  • the auxiliary PWM converter control system necessary for the invention may be a virtually self-contained add-on enhancement to the above known type of control system, and may comprise a digital controller with frequency-specific DQ regulator loops or a sliding mode control. Alternatively, other known techniques could be used.
  • the control system for the supply bridge 4 comprising VSD regulator functions 40 and current regulator function 32, may in fact have sufficient performance to allow its adaptation to facilitate implementation of the enhanced control of the auxiliary converter 10. Alternatively, additional dedicated regulators may be used.
  • the VSD regulator functions 40 are shared, but that the auxiliary PWM converter 10 has a dedicated current regulator 34.
  • it is essential that the thyristor supply bridge controls and auxiliary PWM converter controls are fully integrated with each other in order to allow the combined power system to be operated in the nine modes described above.
  • the auxiliary PWM converter 10 employs an AC line current transducer 38 that provides a current feedback signal 35 to a current regulator 34, which regulates the auxiliary PWM supply converter 10 in order to satisfy the overall requirements of a set of functions in the VSD regulator 40, these functions being represented by the current regulator reference signal 39.
  • the VSD regulator must be set up to apportion load between the thyristor supply bridge 4 and auxiliary PWM supply converter 10, according to the required operating mode.
  • An AC line voltage transducer 48 is linked to the supply line of the thyristor supply bridge 4 and provides a phase reference signal 50 for processing in feedback processor 46.
  • the feedback processor 46 also receives the current feedback signal 33 from the same AC supply line and decomposes it into fundamental "real", fundamental "reactive” and harmonic components. Reference signals 41, 43 and 45 are then generated according to the required system operating mode, .
  • Signals 41 and 43 are circulating current trimming signals and may be employed to adjust the contributions of thyristor supply bridge 4 and auxiliary PWM converter 10 to load current.
  • the adjustments may be such as to force a circulating current to flow in the main AC supply network 1, from thyristor supply bridge 4, via DC link filter terminals 8 and 12 and the auxiliary PWM converter 10. This is clockwise circulating power flow.
  • this circulation may be regulated by the VSD regulator 40.
  • the harmonic content of the circulating current may also be regulated, if desired, by means of the feedback processor 46.
  • Harmonic and MVAr reference signals 45 are employed to enable the auxiliary PWM converter 10 to source and sink fundamental and harmonic currents, at whatever angular displacement from the phase reference signal 50 is appropriate for the required operating mode.
  • thyristor supply bridge reference signal 37 is generated by conventional VSD regulator functions and the auxiliary PWM converter reference signals 39, 43, 45 are set to zero.
  • thyristor supply bridge reference signal 37 is generated by conventional VSD regulator functions and the feedback processor 46 outputs the auxiliary PWM converter reference signal 45, this being an AC supply network fundamental frequency sine wave with a leading power factor.
  • thyristor supply bridge reference signal 37 is generated by conventional VSD regulator functions and the auxiliary converter reference signal 45 is again derived by the feedback processor 46, signal 45 being a series of AC supply network harmonic frequency sine waves.
  • a key benefit of this system is provided by the integration of the control functions of the thyristor supply bridge 4 and the auxiliary PWM converter 10, whereby the current harmonics drawn by the thyristor supply bridge in its supply line simply form the active filtration reference signal by virtue of the current feedback 33, with the auxiliary PWM converter 10 performing the active filter function.
  • active filters measure voltage harmonics and employ complex algorithms from which a filter current reference signal is derived.
  • an active filter is dedicated to the filtration of current harmonics that are drawn by a particular piece of equipment, it is conventional to provide the active filter with its own feedback transducers and regulator system.
  • a typical active filter also requires its own DC bus filter and supporting voltage control system.
  • the active filter concept of the present invention can be far simpler than other systems, provided that the primary source of harmonic pollution on the AC supply network is integrated with the filter function.
  • the equipment described can typically be configured to perform that function without requiring additional hardware, the exception being the case where the external source of harmonic pollution dominates over that of the integrated thyristor supply bridge.
  • the regulator would be required to provide active damping of resonant modes associated with auxiliary PWM converter carrier wave filters and various impedances connected to the supply network 1.
  • reference signal 39 for the auxiliary PWM converter 10 is generated by conventional VSD regulator functions and the thyristor supply bridge reference signal 37 is set to zero.
  • the feedback processor 46 identifies the AC line current harmonics that are associated with DC link current ripple (and potential DC link current discontinuity). From this information, opposing reference signal components 41, 43 are generated for summation into thyristor supply bridge and auxiliary PWM converter current regulators 32, 34, respectively.
  • the thyristor supply bridge current increases by a predetermined value of amp. seconds integral (Coulombs) per half cycle, while the PWM supply bridge current is reduced by a corresponding amp. seconds integral.
  • the auxiliary PWM converter currents closely correspond with the circulating current trim reference signal 43.
  • the balanced amp. second integrals result in the presence of the circulating current, described previously.
  • LV AC supply network IL may detract from the effectiveness of the auxiliary PWM converter 10 if the source impedance on that network is particularly high, unless the harmonics appearing on the supply are taken into account during the design process.
  • some of the operating modes may be merged. For example, supply harmonics and power factor may be corrected simultaneously, as in Modes 2 and 3. However, when modes are merged, compromises will be required between converter functionality in different modes. For example, ability of the auxiliary PWM converter to cancel supply harmonics will conflict with its ability to compensate for extreme power factor excursions on the supply network.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Rectifiers (AREA)
  • Inverter Devices (AREA)

Abstract

L'invention porte sur une combinaison de convertisseurs électriques de puissance transformant le courant c.a. du réseau (1) en courant c.c. alimentant une charge c.c. (2) ladite combinaison comprend: un redresseur (4) à pont d'alimentation à thyristor à commande de phase; et un convertisseur PWM (10) auxiliaire relié aux bornes du filtre de sortie c.c. du pont d'alimentation à thyristor (4) et également relié à une alimentation pouvant être: le réseau c.a. (1), une alimentation c.a. indépendante du réseau ou une source c.c. basse tension.
PCT/GB2006/002239 2005-06-23 2006-06-20 Ameliorations de convertisseurs electriques de puissance Ceased WO2006136801A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0512763A GB2427512A (en) 2005-06-23 2005-06-23 Electrical power converters
GB0512763.4 2005-06-23

Publications (2)

Publication Number Publication Date
WO2006136801A2 true WO2006136801A2 (fr) 2006-12-28
WO2006136801A3 WO2006136801A3 (fr) 2007-12-13

Family

ID=34855995

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2006/002239 Ceased WO2006136801A2 (fr) 2005-06-23 2006-06-20 Ameliorations de convertisseurs electriques de puissance

Country Status (2)

Country Link
GB (1) GB2427512A (fr)
WO (1) WO2006136801A2 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2922382A1 (fr) * 2007-10-16 2009-04-17 Converteam Sas Soc Par Actions Convertisseur de courant bidirectionnel
JP2014533487A (ja) * 2011-11-15 2014-12-11 ゼネラル・エレクトリック・カンパニイ Ｈブリッジに基づく電力変換器
RU2551427C1 (ru) * 2014-05-23 2015-05-27 Открытое акционерное общество Научно-исследовательский и конструкторско-технологический институт подвижного состава (ОАО "ВНИКТИ") Способ и устройство стабилизации трехфазного переменного напряжения

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007046511B4 (de) * 2007-09-28 2017-04-27 Siemens Aktiengesellschaft Stromrichter mit unterbrechbarem Parallelkreis und Umrichter mit zwei parallelkreis-unterbrechenden Stromrichtern
DE102008049536B3 (de) * 2008-09-29 2010-06-24 Siemens Aktiengesellschaft Kreisstromunterdrückende Ansteuerung bei einer Gleichrichterschaltung
NO20100985A1 (no) * 2010-07-06 2011-11-21 Rolls Royce Marine As Power Electric Systems Bergen Styringsinnretning og fremgangsmåte for styring av en vekselstrømsmotor
CN101944843B (zh) * 2010-10-08 2012-08-15 哈尔滨工业大学 多脉波整流系统的直流侧回收式谐波抑制系统及方法
WO2014085591A2 (fr) * 2012-11-30 2014-06-05 Abb Technology Ag Conversion de puissance
CN107112914B (zh) * 2014-10-15 2019-07-02 大金工业株式会社 有源滤波器和交流直流转换装置
EP3379679A1 (fr) * 2017-03-23 2018-09-26 Siemens Aktiengesellschaft Système d'alimentation en énergie électrique
CN108111030B (zh) * 2017-12-07 2020-09-15 上海交通大学 混合型海上风场直流换流器
DE102020000126A1 (de) 2019-01-21 2020-07-23 Sew-Eurodrive Gmbh & Co Kg Antriebssystem, aufweisend einen ersten Umrichter und zumindest einen zweiten Umrichter
DE102020124964A1 (de) * 2020-09-24 2022-03-24 Sma Solar Technology Ag Verfahren zum betrieb eines hybrid-gleichrichters, hybrid-gleichrichter und elektrolyseanlage mit einem derartigen hybrid-gleichrichter
CN112838780B (zh) * 2021-02-10 2024-12-17 中国人民解放军海军工程大学 一种h桥快控电源以及应用该电源的电子装置

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2737946B1 (fr) * 1995-08-17 1997-10-31 Electricite De France Dispositif de commande de l'alimentation d'une machine electrique
JP2000014156A (ja) * 1998-06-23 2000-01-14 Fuji Electric Co Ltd 電力変換装置の制御方法
US20030202368A1 (en) * 2002-04-26 2003-10-30 Paul Ierymenko System and method for providing power factor correction
JP4411845B2 (ja) * 2003-02-13 2010-02-10 株式会社明電舎 並列型ａｃ−ｄｃ変換器

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2922382A1 (fr) * 2007-10-16 2009-04-17 Converteam Sas Soc Par Actions Convertisseur de courant bidirectionnel
JP2014533487A (ja) * 2011-11-15 2014-12-11 ゼネラル・エレクトリック・カンパニイ Ｈブリッジに基づく電力変換器
RU2551427C1 (ru) * 2014-05-23 2015-05-27 Открытое акционерное общество Научно-исследовательский и конструкторско-технологический институт подвижного состава (ОАО "ВНИКТИ") Способ и устройство стабилизации трехфазного переменного напряжения

Also Published As

Publication number Publication date
GB2427512A (en) 2006-12-27
GB0512763D0 (en) 2005-07-27
WO2006136801A3 (fr) 2007-12-13

Similar Documents

Publication Publication Date Title
US10224830B2 (en) System and method for controlling a back-to-back three-level converter with voltage ripple compensation
US6654261B2 (en) Inverter DC link volts “tooth” modulation scheme
US10516365B1 (en) DC voltage control in renewable energy based multilevel power converter
Huang et al. Design of power decoupling strategy for single-phase grid-connected inverter under nonideal power grid
US7327113B2 (en) Electric starter generator system employing bidirectional buck-boost power converters, and methods therefor
US7800348B2 (en) Motor drive with VAR compensation
US6404655B1 (en) Transformerless 3 phase power inverter
JP6087531B2 (ja) 電力変換装置
US20140217827A1 (en) Apparatus for and method of operation of a power inverter system
CA2848107A1 (fr) Dispositif de regulation de decouplage de puissance et procede pour systeme de conversion de puissance
US20120163044A1 (en) Multilevel power converter or inverter arrangement using h bridges
WO2006136801A2 (fr) Ameliorations de convertisseurs electriques de puissance
US11065968B2 (en) Integrated multi-source IPT system
WO2019215842A1 (fr) Dispositif de conversion de puissance
Li et al. Double line frequency ripple cancelling for single-phase quasi-Z-source inverter
Ezhilvannan et al. Novel fault analysis and compensation in 5-Level multilevel DC-AC converter
Amin et al. Practical implementation of high-efficiency multiple-input converter embedding renewables and energy storage for DC-microgrid applications
Choi et al. Transformerless line-interactive UPS with low ground leakage current
US7099165B1 (en) Network harmonic scrubber
Chakraborty et al. An active power management to prevent reverse power flow and ITOAGI-PLL control to enhance power quality in SyRG DG-PV standalone system
KR20150062999A (ko) 에너지 저장 장치용 충전 회로를 포함하는 전기 구동 시스템, 그리고 에너지 저장 장치의 작동 방법
Bernet et al. Grid-connected voltage source converters with integrated multilevel-based active filters
JP2017103902A (ja) 電力変換装置
Itoh et al. Input current stabilization control of a matrix converter with boost-up functionality
Nikitha et al. A Four Switch Three-Port DC/DC/AC Converter Based on Power Decoupling Technique—Simulation Analysis

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

WWW Wipo information: withdrawn in national office

Country of ref document: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06744257

Country of ref document: EP

Kind code of ref document: A2