CN106160542B - Modularization multi-level converter physical simulation device with potential isolation - Google Patents
Modularization multi-level converter physical simulation device with potential isolation Download PDFInfo
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Abstract
The invention relates to a modularized multi-level converter physical simulation device with potential isolation, which comprises a plurality of sub-module simulation units arranged on a sub-module simulation board card; the submodule analog unit comprises a power supply interface circuit, a control circuit and a cascade submodule main circuit which are sequentially connected. The device provided by the invention can realize multi-level potential isolation among the sub module main circuit, the sub module controller, the wave recording system, the case and the screen cabinet of the modularized multi-level converter valve physical simulation device, and realize safe and reliable operation among high and low potentials and between the digital controller and an analog device; the potential isolation contradiction between the requirement of a 24V direct-current low-voltage power supply of a single submodule and the direct-current thousands of volts of high voltage formed after series connection can be solved.
Description
Technical Field
The invention relates to a potential isolation device for flexible direct current transmission, in particular to a physical simulation device of a modular multilevel converter with potential isolation.
Background
The high-voltage direct current technology (VSC-HVDC) based on the voltage source converter has the advantages of capability of supplying power to an island, independent adjustment of active power and reactive power, no phase change failure, no need of reactive compensation, capability of transmitting power through a long-distance submarine cable and the like. In recent years, the technical theory of this type of power transmission and engineering construction are rapidly developing worldwide. On the basis of the past, the application of a high-voltage direct-current transmission technology (MMC-HVDC) based on a novel Modular Multi-level voltage source Converter (MMC) in the technical field of high-voltage direct-current transmission is realized, the successful commissioning of a 20MVA flexible direct-current transmission demonstration project in a wind power plant is realized, and along with the development of larger-scale urban power supply direct-current transmission system construction, a control strategy and a control protection system for verifying the project and a Modular Multi-level Converter physical simulation device for potential isolation of a control strategy of a valve base electronic control system are urgently needed.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a modularized multi-level converter physical simulation device with potential isolation, which can realize multi-level potential isolation among a submodule main circuit, a submodule controller, a case and a screen cabinet in the modularized multi-level converter valve physical simulation device and realize safe and reliable operation among high and low potentials and between a digital controller and an analog device.
The purpose of the invention is realized by adopting the following technical scheme:
the invention provides a modularized multi-level converter physical simulation device with potential isolation, which is improved in that the physical simulation device comprises a sub-module simulation board card provided with a sub-module simulation unit; the submodule analog unit comprises a power supply interface circuit, a control circuit and a cascade submodule main circuit which are sequentially connected.
Furthermore, a multi-pin plug on the submodule simulation board card is respectively connected with an incoming line and an outgoing line of the cascade submodule main circuit to form a closed loop.
Furthermore, the cascade submodule main circuit is formed by cascading N submodules; the submodule comprises a circuit breaker, a thyristor, two IGBTs, a voltage-sharing resistor and a capacitor; the two IGBTs are connected in series and then connected in parallel with the voltage-sharing resistor and the capacitor; the circuit breaker, the thyristor and the lower tube IGBT are connected in parallel; an upper tube IGBT emitter in the two IGBTs is connected with a lower tube IGBT source; the positive electrode of the capacitor is connected with the collector electrode of the upper tube IGBT, and the negative electrode of the capacitor is connected with the emitter electrode of the lower tube IGBT; and the upper tube IGBT and the lower tube IGBT are connected with diodes in an anti-parallel mode.
Furthermore, an isolation power supply module is used for supplying power between an upper tube IGBT and a lower tube IGBT of the sub-module; when an upper tube IGBT in the submodule is turned off and a lower tube IGBT in the submodule is turned on, the submodule does not provide direct current voltage, bridge arm current flows from the lower tube IGBT or an anti-parallel diode, and a capacitor is bypassed; when an upper tube IGBT in the submodule is switched on and a lower tube IGBT in the submodule is switched off, the submodule does not provide direct current voltage, bridge arm current flows from the upper tube IGBT or an anti-parallel diode, and a capacitor is bypassed.
Furthermore, the control circuit comprises a digital processor, and a capacitance voltage detection circuit, a module board state detection circuit and a switching element drive circuit which are respectively connected with the digital processor; the digital processor is a singlechip, a CPLD processor, an FPGA processor or a DSP processor; the capacitance voltage detection circuit uses two lead wires to lead the sub-module capacitance voltage into a chip analog quantity input pin of a digital processor through a scaling circuit so as to collect voltage; the module state detection circuit is used for detecting the state of the sub-module simulation board card; the switching element driving circuit obtains control commands of the switching devices IGBT and thyristor from an output pin of the digital processor, and outputs driving signals to the control pins of the IGBT and thyristor through amplification and conditioning.
Further, the power supply interface circuit comprises an isolated power supply, an optical fiber interface and an application interface; the optical fiber interface and the application interface are both connected with a digital processor of the control circuit; the isolation power supply is connected with the same switch power supply providing board of the plurality of submodule simulation board cards.
Furthermore, a plurality of submodule simulation units on the submodule simulation board card are integrally designed and then integrally installed in the converter valve electric shielding cabinet, and the converter valve electric shielding cabinet, the AC-DC converter and the isolation transformer are sequentially connected; the isolation transformer is provided with a connecting end connected with a power grid.
Further, the output 0 potential of the 24V direct-current power supply corresponding to each converter valve electric screen shielding cabinet is connected with the negative electrode of the capacitor of the submodule with the lowest potential in the converter valve electric screen shielding cabinet; the input potential of the 24V direct-current power supply is suspended and is output to each submodule; the input 0 bit of an isolation power supply module on each submodule is connected with the output 0 bit of a 24V power supply, and the output 0 bit of the isolation power supply module is connected with the negative electrode of a capacitor in each submodule; the potential difference in the shielding cabinet of the electric screen of the converter valve is borne by a 220V isolation transformer, so that the potential difference between a 24V direct-current power supply and the potential difference in the submodule is reduced; the potential difference between the 24V direct current power supply and the submodule does not exceed 1000V at most.
Furthermore, the isolation transformer adopts a single-phase adjustable transformation ratio 1:1 winding mode, a 220V alternating current power supply transmits electric energy to the secondary side of the physical simulation device through magnetic coupling, higher harmonics of the secondary side are reduced, and the primary side is influenced by electrical faults of the secondary side.
Compared with the closest prior art, the technical scheme provided by the invention has the following excellent effects:
the modularized multi-level converter physical simulation device with potential isolation provided by the invention can realize multi-level potential isolation among a sub-module main circuit, a sub-module controller, a wave recording system, a case and a screen cabinet of the modularized multi-level converter valve physical simulation device, and realize safe and reliable operation among high and low potentials and between a digital controller and an analog device.
The physical simulation device of the modular multilevel converter with potential isolation provided by the invention can solve the potential isolation contradiction between the requirement of a single submodule 24V direct-current low-voltage power supply and the direct-current thousands-volt high voltage formed after series connection.
Drawings
FIG. 1 is a block diagram of converter valve physical simulation apparatus;
FIG. 2 is a layout diagram of a simulation board card of a converter valve submodule provided by the invention;
fig. 3 is an electrical wiring diagram of a modular multilevel converter sub-module provided by the present invention;
fig. 4 is a schematic diagram of the electrical isolation of the converter valve electrical shielding cabinet provided by the present invention through the commercial power AC220V and the isolation transformer.
Detailed Description
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
The invention provides a modularized multi-level converter physical simulation device with potential isolation, which comprises a plurality of sub-module simulation units arranged on a sub-module simulation board card; the submodule analog unit comprises a power supply interface circuit, a control circuit and a cascade submodule main circuit which are sequentially connected. The structure of multiple modules cascaded on the same board card is shown in fig. 1. The circuit board of the multilevel voltage source converter integrates a plurality of MMC sub-modules of the multilevel voltage source converter with equivalent reduction,
the multi-pin plug on the sub-module simulation board card is connected with the main circuit of the cascade sub-module through an incoming line of the main circuit of the cascade sub-module and then connected to the multi-pin plug through an outgoing line of the main circuit of the cascade sub-module to form a closed loop.
The cascade submodule main circuit is formed by cascading N submodules; the submodules comprise a circuit breaker, a thyristor, two IGBTs (S1 and S2), a voltage-sharing resistor (R1) and a polar electrolytic capacitor (C) which can be switched in; the two IGBTs are connected in series and then connected in parallel with the voltage-sharing resistor and the capacitor; the circuit breaker, the thyristor and the lower tube IGBT are connected in parallel; an upper tube IGBT emitter in the two IGBTs is connected with a lower tube IGBT source; the positive electrode of the capacitor is connected with the collector electrode of the upper tube IGBT, and the negative electrode of the capacitor is connected with the emitter electrode of the lower tube IGBT; the upper tube IGBT and the lower tube IGBT are connected with diodes D1 and D2 in an anti-parallel mode.
An isolation power supply module is adopted to supply power between an upper tube IGBT and a lower tube IGBT of the sub-module; when an upper tube IGBT in the submodule is turned off and a lower tube IGBT in the submodule is turned on, the submodule does not provide direct current voltage, bridge arm current flows from the lower tube IGBT or an anti-parallel diode, and a capacitor is bypassed; when an upper tube IGBT in the submodule is switched on and a lower tube IGBT in the submodule is switched off, the submodule does not provide direct current voltage, bridge arm current flows from the upper tube IGBT or an anti-parallel diode, and a capacitor is bypassed.
The converter valve sub-module adopts an integrated overall layout of 1 controller for controlling and driving 1 sub-module, and each FPGA controls one half-bridge. Because the electric potentials simulating each sub-module board card are different, the main circuit is required to be driven by the isolation drive after the power is taken from the same power supply through the isolation power supply module.
The control circuit comprises a digital processor, and a capacitance voltage detection circuit, a module board state detection circuit and a switching element drive circuit which are respectively connected with the digital processor; the digital processor is a singlechip, a CPLD processor, an FPGA processor or a DSP processor. The capacitor voltage detection circuit introduces the submodule capacitor voltage into an analog quantity input pin of a chip of a digital processor through the scaling-down circuit through two short lead wires to carry out voltage acquisition. The module state detection circuit works in a similar manner to the capacitor voltage detection circuit. The switching element driving circuit obtains control commands of the switching devices IGBT and thyristor from an output pin of the digital processor, and outputs driving signals to the control pins of the IGBT and thyristor through amplification and conditioning.
The power supply interface circuit comprises an isolation power supply, an optical fiber interface and an application interface; the optical fiber interface and the application interface are both connected with a digital processor of the control circuit; the isolation power supply is connected with the same switch power supply providing board of the plurality of submodule simulation board cards.
A plurality of sub-module simulation units on the sub-module simulation board card are integrally designed and then integrally installed in a converter valve electrical shielding cabinet, and the converter valve electrical shielding cabinet, an AC-DC converter and an isolation transformer are sequentially connected; and the isolation transformer is connected to a power grid. The isolation transformer is in a single-phase adjustable transformation ratio 1:1 winding mode, a 220V alternating current power supply transmits electric energy to the secondary side through magnetic coupling, higher harmonics of the secondary side are reduced, and the primary side is prevented from being influenced by electrical faults of the secondary side.
Considering that the voltage to ground of the valve module reaches a peak value when the movable mould platform simulates a single-stage grounding short circuit and considering design allowance, the electrical isolation requirement of the power supply and the main circuit part of the control circuit is more than 5000V, and the board card of the sub-module is required to be distributed and separated between the main circuit and the control circuit when the PCB is designed.
Since the cost is increased sharply by providing a module power supply having a high insulation capability on each submodule, an isolation capability of 10kV or more is provided by providing an isolation transformer for each cabinet.
And the 0 potential of the output of the 24V direct-current power supply corresponding to each converter valve electric shielding cabinet is connected with the negative electrode of the capacitor of the submodule with the lowest potential in the shielding cabinet. The input potential of the 24V direct current power supply is suspended and output to each module. Each module is provided with an isolation power supply module, an input 0 bit of the isolation power supply module is connected with an output 0 bit of a 24V power supply, and the output 0 bit of the isolation power supply module is connected with the negative electrode of a capacitor in each sub-module. Therefore, the 220V isolation transformer is used for bearing most of potential difference in a flat cabinet, the potential difference in the 24V direct-current power supply and the submodule is correspondingly reduced, and the maximum potential difference does not exceed 1000V.
Finally, it should be noted that: although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can make modifications and equivalents to the embodiments of the present invention without departing from the spirit and scope of the present invention, which is set forth in the claims of the present application.
Claims (6)
1. A modularized multi-level converter physical simulation device with potential isolation is characterized by comprising a submodule simulation board card, a submodule simulation unit and a voltage isolation module, wherein the submodule simulation board card is provided with a submodule simulation unit; the submodule analog unit comprises a power supply interface circuit, a control circuit and a cascade submodule main circuit which are sequentially connected;
the plurality of sub-module simulation units on the sub-module simulation board card are integrally designed and then integrally installed in the converter valve electrical shielding cabinet, and the converter valve electrical shielding cabinet, the AC-DC converter and the isolation transformer are sequentially connected; the isolation transformer is provided with a connecting end connected with a power grid;
the output 0 potential of the 24V direct-current power supply corresponding to each converter valve electric screen shielding cabinet is connected with the negative electrode of the capacitor of the submodule with the lowest potential in the converter valve electric screen shielding cabinet; the input potential of the 24V direct-current power supply is suspended and is output to each submodule; the input 0 bit of an isolation power supply module on each submodule is connected with the output 0 bit of a 24V power supply, and the output 0 bit of the isolation power supply module is connected with the negative electrode of a capacitor in each submodule; the potential difference in the shielding cabinet of the electric screen of the converter valve is borne by a 220V isolation transformer, so that the potential difference between a 24V direct-current power supply and the potential difference in the submodule is reduced; the highest potential difference between the 24V direct-current power supply and the submodule does not exceed 1000V;
the isolation transformer adopts a single-phase adjustable transformation ratio 1:1 winding mode, and transmits electric energy to the secondary side of the physical simulation device through a 220V alternating current power supply through magnetic coupling, so that higher harmonics of the secondary side are reduced, and the primary side is influenced by electrical faults of the secondary side.
2. The physical simulation device of claim 1, wherein the multi-pin plug on the sub-module simulation board is connected with an incoming line and an outgoing line of the main circuit of the cascaded sub-module respectively to form a closed loop.
3. The physical simulation apparatus of claim 1, wherein the cascaded sub-module primary circuit is comprised of a cascade of N sub-modules; the submodule comprises a circuit breaker, a thyristor, two IGBTs, a voltage-sharing resistor and a capacitor; the two IGBTs are connected in series and then connected in parallel with the voltage-sharing resistor and the capacitor; the circuit breaker, the thyristor and the lower tube IGBT are connected in parallel; an upper tube IGBT emitter in the two IGBTs is connected with a lower tube IGBT source; the positive electrode of the capacitor is connected with the collector electrode of the upper tube IGBT, and the negative electrode of the capacitor is connected with the emitter electrode of the lower tube IGBT; and the upper tube IGBT and the lower tube IGBT are connected with diodes in an anti-parallel mode.
4. The physical simulation apparatus of claim 3, wherein an isolated power module is used to supply power between an upper tube IGBT and a lower tube IGBT of the sub-module; when an upper tube IGBT in the submodule is turned off and a lower tube IGBT in the submodule is turned on, the submodule does not provide direct current voltage, bridge arm current flows from the lower tube IGBT or an anti-parallel diode, and a capacitor is bypassed; when an upper tube IGBT in the submodule is switched on and a lower tube IGBT in the submodule is switched off, the submodule does not provide direct current voltage, bridge arm current flows from the upper tube IGBT or an anti-parallel diode, and a capacitor is bypassed.
5. The physical simulation apparatus of claim 1, wherein the control circuit comprises a digital processor, and a capacitance voltage detection circuit, a module board state detection circuit, and a switching element drive circuit, which are connected to the digital processor, respectively; the digital processor is a singlechip, a CPLD processor, an FPGA processor or a DSP processor; the capacitance voltage detection circuit uses two lead wires to lead the sub-module capacitance voltage into a chip analog quantity input pin of a digital processor through a scaling circuit so as to collect voltage; the module state detection circuit is used for detecting the state of the sub-module simulation board card; the switching element driving circuit obtains control commands of the switching devices IGBT and thyristor from an output pin of the digital processor, and outputs driving signals to the control pins of the IGBT and thyristor through amplification and conditioning.
6. The physical simulation apparatus of claim 1, wherein the power interface circuit comprises an isolated power supply, a fiber optic interface, and an application interface; the optical fiber interface and the application interface are both connected with a digital processor of the control circuit; the isolation power supply is connected with the same switch power supply providing board of the plurality of submodule simulation board cards.
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| WO2010102667A1 (en) * | 2009-03-11 | 2010-09-16 | Abb Technology Ag | A modular voltage source converter and an energy source unit |
| CN102130612A (en) * | 2010-12-20 | 2011-07-20 | 中国电力科学研究院 | Integrated control sub-module board for simulating multi-level modular converter (MMC) sub-module |
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| WO2010102667A1 (en) * | 2009-03-11 | 2010-09-16 | Abb Technology Ag | A modular voltage source converter and an energy source unit |
| CN102130612A (en) * | 2010-12-20 | 2011-07-20 | 中国电力科学研究院 | Integrated control sub-module board for simulating multi-level modular converter (MMC) sub-module |
| CN102313850A (en) * | 2011-06-24 | 2012-01-11 | 中国电力科学研究院 | Physical real-time dynamic simulation device for flexible direct current transmission system |
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