A simplified five-level voltage source converter

Abstract

A simplified five-level voltage source conversion device is used in a power conversion system and belongs to the field of power electronic converters. The present invention includes four capacitors, wherein the first capacitor C1 and the second capacitor C2 are bus capacitors, and the third capacitor C3 and the fourth capacitor C4 are clamping capacitors. A first connection terminal, a second connection terminal, a third connection terminal, a fourth connection terminal, a fifth connection terminal, a sixth connection terminal, a seventh connection terminal, an eighth connection terminal, a ninth connection terminal; and ten insulated gate bipolar transistors IGBT1 to IGBT10. The present invention reduces the number of switching tubes whose switching states change during the level conversion process, and the control is simple. There is no need for clamping diodes, and the number of capacitors and switching tubes used is also extremely small.

Description

Technical Field

[0001] The present invention relates to a simplified five-level voltage source conversion device for use in a power conversion system and belongs to the field of power electronic converters. Background Art

[0002] In recent years, with the development of technology, power electronics technology has developed rapidly under the impetus of increasingly high industrial requirements. Multilevel conversion devices have the advantages of low device voltage stress, high power, low switching frequency, low total harmonic distortion rate of the output waveform, and low system electromagnetic interference. Therefore, power electronic devices are also widely used in various industrial fields. The multilevel converter topology is divided into diode-clamped type, flying-capacitor type, and cascaded type. These three topologies are widely used. However, these three topology types have disadvantages that cannot be ignored. The number of clamping diodes used in diode clamping increases exponentially with the number of levels, so it is difficult to be used on a large scale in the high-level field. Although the flying-capacitor type omits the clamping diodes, it brings the problems of capacitor voltage control and an increase in the number of capacitors. The cascaded topology requires an external power supply and is extremely inconvenient to use in practice. Therefore, it is extremely important to find a multilevel converter topology that overcomes many disadvantages.

[0003] Currently, many optimized five-level structures have been proposed. However, most five-level structures cannot effectively solve the problems of the number of topology devices and cost. The five-level topology described in this patent only requires a very small number of capacitors and switching tubes and does not require clamping capacitors. The circuit topology is simple, the level output is stable, and the control method is simple. It has significant advantages both in theory and in production practice. Summary of the Invention

[0004] In view of the problems existing in the above technologies, this patent provides a five-level converter device with a simple topology, a stable number of output levels, a simple control method, a very small number of capacitors and insulated gate bipolar transistors (IGBTs) used, no need for clamping diodes, and some switching devices can use low-cost SI material switching devices.

[0005] 1. To achieve the above object, this voltage source five-level conversion device includes a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4; a first terminal (1), a second terminal (2), a third terminal (3), a fourth terminal (4), a fifth terminal (5), a sixth terminal (6), a seventh terminal (7), an eighth terminal (8), a ninth terminal (9); and ten insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4, IGBT5, IGBT6, IGBT7, IGBT8, IGBT9, IGBT10;

[0006] It is characterized in that a first capacitor C1 is connected between a first terminal (1) and a second terminal (2);

[0007] A second capacitor C2 is connected between the second terminal (2) and a third terminal (3);

[0008] A third capacitor C3 is connected between a fifth terminal (5) and a fourth terminal (4);

[0009] A fourth capacitor C4 is connected between the fourth terminal (4) and a sixth terminal (6);

[0010] The collector of an insulated gate bipolar transistor IGBT1 is connected to the first terminal (1), and the emitter of the insulated gate bipolar transistor IGBT1 is connected to the fifth terminal (5);

[0011] The collector of an insulated gate bipolar transistor IGBT2 is connected to the fifth terminal (5), and the emitter of the insulated gate bipolar transistor IGBT2 is connected to a seventh terminal (7);

[0012] The collector of an insulated gate bipolar transistor IGBT3 is connected to the seventh terminal (7), and the emitter of the insulated gate bipolar transistor IGBT3 is connected to the fourth terminal (4);

[0013] The collector of an insulated gate bipolar transistor IGBT4 is connected to the seventh terminal (7), and the emitter of the insulated gate bipolar transistor IGBT4 is connected to a ninth terminal (9);

[0014] The collector of an insulated gate bipolar transistor IGBT5 is connected to the ninth terminal (9), and the emitter of the insulated gate bipolar transistor IGBT5 is connected to an eighth terminal (8);

[0015] The collector of an insulated gate bipolar transistor IGBT6 is connected to the fourth terminal (4), and the emitter of the insulated gate bipolar transistor IGBT6 is connected to the eighth terminal (8);

[0016] The collector of an insulated gate bipolar transistor IGBT7 is connected to the eighth terminal (8), and the emitter of the insulated gate bipolar transistor IGBT7 is connected to the sixth terminal (6);

[0017] The collector of an insulated gate bipolar transistor IGBT8 is connected to the sixth terminal (6), and the emitter of the insulated gate bipolar transistor IGBT8 is connected to the third terminal (3);

[0018] The collector of an insulated gate bipolar transistor IGBT9 is connected to the fourth terminal (4), and the emitter of the insulated gate bipolar transistor IGBT9 is connected to the emitter of the insulated gate bipolar transistor IGBT10;

[0019] The collector of the insulated gate bipolar transistor IGBT10 is connected to the second terminal (2), and the emitter of the insulated gate bipolar transistor IGBT10 is connected to the emitter of the insulated gate bipolar transistor IGBT9.

[0020] The emitter of the insulated gate bipolar transistor IGBT9 is connected to the emitter of the insulated gate bipolar transistor IGBT10, and the ninth terminal is the output terminal and is connected between the emitter of the insulated gate bipolar transistor IGBT4 and the collector of the insulated gate bipolar transistor IGBT5.

[0021] Within one working cycle of the five-level topology unit, the five-level topology unit sequentially operates in the first working state, the second working state, the third working state, the fourth working state, and the fifth working state. When operating in the first working state, the voltage at the output terminal is twice the voltage of the DC positive terminal; when operating in the second working state, the voltage at the output terminal is equal to the voltage of the DC positive terminal; when operating in the third working state, the voltage at the output terminal is zero; when operating in the fourth working state, the voltage at the output terminal is equal to the voltage of the DC negative terminal; when operating in the fifth working state, the voltage at the output terminal is twice the voltage of the DC negative terminal.

[0022] When the insulated gate bipolar transistors IGBT1, IGBT2, and IGBT4 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 2Vdc, where Vdc represents the power supply voltage;

[0023] When the insulated gate bipolar transistors IGBT2 and IGBT4 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs Vdc;

[0024] When the insulated gate bipolar transistors IGBT3, IGBT4, IGBT9, and IGBT10 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 0; or when the insulated gate bipolar transistors IGBT5, IGBT6, IGBT9, and IGBT10 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 0;

[0025] When the insulated gate bipolar transistors IGBT5 and IGBT7 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs -Vdc;

[0026] When the insulated gate bipolar transistors IGBT5, IGBT7, and IGBT8 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs -2Vdc.

[0027] Each insulated gate bipolar transistor can also be replaced by an integrated gate-commutated thyristor, a gate-turn-off thyristor, a power transistor, and a power field-effect transistor for use.

[0028] The switching frequencies of insulated gate bipolar transistors IGBT4 and IGBT5 are not high, and SI material switching tubes can be used to reduce the cost of the five-level topology.

[0029] A diode is anti-parallelly connected to each switching tube. Each switching tube and its anti-parallel diode are integrally packaged together.

[0030] The first capacitor C1, the second capacitor C2, the third capacitor, the fourth capacitor; insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4, IGBT5, IGBT6, IGBT7, IGBT8, IGBT9, IGBT10, the drive board, and the control board are integrally packaged together.

[0031] The described controller is used to control the on state or off state of each switching device in the five-level topology unit, so that the converter operates in the corresponding working state.

[0032] The control unit is respectively connected to each of the switching devices, and the control unit provides drive signals for each of the switching devices; each of the switching devices conducts or cuts off under the corresponding drive signal.

[0033] The control signal of the control unit includes a sine modulation wave and three triangular carrier waves with the same frequency and amplitude, namely triangular carrier wave A, triangular carrier wave B, and triangular carrier wave C;

[0034] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage value of the triangular carrier wave A at the same moment in the positive half cycle as the drive signals for the first switching device, the second switching device, and the fourth switching device;

[0035] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular carrier wave A and the triangular carrier wave B at the same moment in the positive half cycle as the drive signals for the second switching device and the fourth device;

[0036] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular modulation wave B and the triangular modulation wave C at the same moment in the positive half cycle as the drive signals for the third switching device, the fourth switching device, the ninth switching device, and the tenth switching device;

[0037] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage value of the triangular modulation wave A at the same moment in the negative half-cycle as the drive signals for the fifth switching device, the seventh switching device, and the eighth switching device;

[0038] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular modulation wave A and the triangular modulation wave B at the same moment in the negative half-cycle as the drive signals for the fifth switching device and the seventh switching device;

[0039] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular modulation wave B and the triangular modulation wave C at the same moment in the negative half-cycle as the drive signals for the fifth switching device, the sixth switching device, the ninth switching device, and the tenth switching device.

[0040] This voltage-source five-level topology only requires four capacitors, namely C1, C2, C3, and C4. Compared with the traditional five-level flying-capacitor topology, six capacitors can be saved per phase, greatly reducing the volume of the circuit. This voltage-source five-level topology does not require clamping diodes. Compared with the traditional diode-clamped five-level topology, six diodes can be saved per phase, greatly reducing the requirement for the number of devices. Compared with the traditional cascaded five-level topology, this voltage-source five-level topology does not require an external power supply, making it more convenient to use; the topology of this five-level voltage-source conversion device is simple, the control method is simple, and the level output is stable; the switching frequencies of the insulated gate bipolar transistors IGBT4 and IGBT5 in this five-level voltage-source conversion device are not high, and Si material switching tubes can be used, saving device costs. Whether in theory or in production practice, this five-level voltage-source converter device has significant advantages. Description of the Drawings

[0041] Figure 1 is the voltage-source five-level topology diagram of this patent;

[0042] Figure 2 is the current path diagram when the circuit of this patent outputs 2Vdc;

[0043] Figure 3 is the current path diagram when the circuit of this patent outputs Vdc;

[0044] Figure 4 is the current path diagram when the circuit of this patent outputs 0;

[0045] Figure 5 is the current path diagram when the circuit of this patent outputs -Vdc;

[0046] Figure 6 It is the current path diagram when the circuit described in this patent outputs -2Vdc;

[0047] Figure 7 It is the topological structure diagram of Embodiment Six of this patent;

[0048] Figure 8 It is the topological structure diagram of Embodiment Seven of this patent;

[0049] Figure 9 It is the topological structure diagram of Embodiment Eight of this patent;

[0050] Figure 10 It is the topological structure diagram of Embodiment Nine of this patent;

[0051] Figure 11 It is the topological structure diagram of Embodiment Ten of this patent;

[0052] Figure 12 It is the topological structure diagram of Embodiment Eleven of this patent;

[0053] Figure 13 It is the trigger signal timing diagram of the single-phase bridge arm of this patent. Specific embodiments

[0054] Next, in combination with the accompanying drawings in the embodiments of this patent, the technical solutions in this patent will be described completely and systematically. Of course, the embodiments described herein are only a part of the embodiments of this patent and do not mean that all embodiments are included. Embodiments that have not made creative modifications to this patent all fall within the protection scope of this patent.

[0055] Please refer to Figure 1 , this voltage source type five-power conversion device includes a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4; a first terminal (1), a second terminal (2), a third terminal (3), a fourth terminal (4), a fifth terminal (5), a sixth terminal (6), a seventh terminal (7), an eighth terminal (8), a ninth terminal (9); and ten insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4, IGBT5, IGBT6, IGBT7, IGBT8, IGBT9, IGBT10;

[0056] Characterized in that the first capacitor C1 is connected between the first terminal (1) and the second terminal (2);

[0057] The second capacitor C2 is connected between the second terminal (2) and the third terminal (3);

[0058] The third capacitor C3 is connected between the fifth terminal (5) and the fourth terminal (4);

[0059] The fourth capacitor C4 is connected between the fourth terminal (4) and the sixth terminal (6);

[0060] The collector of the insulated gate bipolar transistor IGBT1 is connected to the first terminal (1), and the emitter of the insulated gate bipolar transistor IGBT1 is connected to the fifth terminal (5);

[0061] The collector of the insulated gate bipolar transistor IGBT2 is connected to the fifth terminal (5), and the emitter of the insulated gate bipolar transistor IGBT2 is connected to the seventh terminal (7);

[0062] The collector of the insulated gate bipolar transistor IGBT3 is connected to the seventh terminal (7), and the emitter of the insulated gate bipolar transistor IGBT3 is connected to the fourth terminal (4);

[0063] The collector of the insulated gate bipolar transistor IGBT4 is connected to the seventh terminal (7), and the emitter of the insulated gate bipolar transistor IGBT4 is connected to the ninth terminal (9);

[0064] The collector of the insulated gate bipolar transistor IGBT5 is connected to the ninth terminal (9), and the emitter of the insulated gate bipolar transistor IGBT5 is connected to the eighth terminal (8);

[0065] The collector of the insulated gate bipolar transistor IGBT6 is connected to the fourth terminal (4), and the emitter of the insulated gate bipolar transistor IGBT6 is connected to the eighth terminal (8);

[0066] The collector of the insulated gate bipolar transistor IGBT7 is connected to the eighth terminal (8), and the emitter of the insulated gate bipolar transistor IGBT7 is connected to the sixth terminal (6);

[0067] The collector of the insulated gate bipolar transistor IGBT8 is connected to the sixth terminal (6), and the emitter of the insulated gate bipolar transistor IGBT8 is connected to the third terminal (3);

[0068] The collector of the insulated gate bipolar transistor IGBT9 is connected to the fourth terminal (4), and the emitter of the insulated gate bipolar transistor IGBT9 is connected to the emitter of the insulated gate bipolar transistor IGBT10;

[0069] The collector of the insulated gate bipolar transistor IGBT10 is connected to the second terminal (2), and the emitter of the insulated gate bipolar transistor IGBT10 is connected to the emitter of the insulated gate bipolar transistor IGBT9;

[0070] The emitter of the insulated gate bipolar transistor IGBT9 is connected to the emitter of the insulated gate bipolar transistor IGBT10, and the ninth connection terminal is the output terminal and is connected between the emitter of the insulated gate bipolar transistor IGBT4 and the collector of the insulated gate bipolar transistor IGBT5.

[0071] Within one working cycle of the five-level topology unit, the five-level topology unit operates in the first working state, the second working state, the third working state, the fourth working state, and the fifth working state in sequence. When operating in the first working state, the voltage at the output terminal is twice the voltage of the DC positive terminal; when operating in the second working state, the voltage at the output terminal is equal to the voltage of the DC positive terminal; when operating in the third working state, the voltage at the output terminal is zero; when operating in the fourth working state, the voltage at the output terminal is equal to the voltage of the DC negative terminal; when operating in the fifth working state, the voltage at the output terminal is twice the voltage of the DC negative terminal.

[0072] When the insulated gate bipolar transistors IGBT1, IGBT2, and IGBT4 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 2Vdc, where Vdc represents the power supply voltage;

[0073] When the insulated gate bipolar transistors IGBT2 and IGBT4 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs Vdc;

[0074] When the insulated gate bipolar transistors IGBT3, IGBT4, IGBT9, and IGBT10 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 0; or when the insulated gate bipolar transistors IGBT5, IGBT6, IGBT9, and IGBT10 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 0;

[0075] When the insulated gate bipolar transistors IGBT5 and IGBT7 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs -Vdc;

[0076] When the insulated gate bipolar transistors IGBT5, IGBT7, and IGBT8 are turned on and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs -2Vdc.

[0077] Each insulated gate bipolar transistor can also be replaced by an integrated gate-commutated thyristor, a gate-turn-off thyristor, a power transistor, and a power field-effect transistor for use.

[0078] The switching frequencies of the insulated gate bipolar transistors IGBT4 and IGBT5 are not high, and SI material switching tubes can be used to reduce the cost of the five-level topology structure.

[0079] A diode is anti-parallel connected to each switching device. Each switching device and its anti-parallel connected diode are integrally packaged together.

[0080] The first capacitor C1, the second capacitor C2, the third capacitor, the fourth capacitor; the insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4, IGBT5, IGBT6, IGBT7, IGBT8, IGBT9, IGBT10, the drive board, and the control board are integrally packaged together.

[0081] The controller is used to control the on-state or off-state of each switching device in the five-level topology unit, so that the converter operates in the corresponding operating state.

[0082] The control unit is respectively connected to each of the switching devices, and the control unit respectively provides drive signals for each of the switching devices; each of the switching devices is turned on or off under the corresponding drive signal.

[0083] The control signal of the control unit includes a sine modulation wave and three triangular carrier waves with the same frequency and amplitude, namely triangular carrier wave A, triangular carrier wave B, and triangular carrier wave C;

[0084] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage value of the triangular carrier wave A at the same moment in the positive half cycle as the drive signals for the first switching device, the second switching device, and the fourth switching device;

[0085] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular carrier wave A and the triangular carrier wave B at the same moment in the positive half cycle as the drive signals for the second switching device and the fourth device;

[0086] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular modulation wave B and the triangular modulation wave C at the same moment in the positive half cycle as the drive signals for the third switching device, the fourth switching device, the ninth switching device, and the tenth switching device;

[0087] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage value of the triangular modulation wave A at the same moment in the negative half cycle as the drive signals for the fifth switching device, the seventh switching device, and the eighth switching device;

[0088] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular modulation wave A and the triangular modulation wave B at the same moment in the negative half-cycle as the drive signals of the fifth switching device and the seventh switching device;

[0089] The control unit uses the comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular modulation wave B and the triangular modulation wave C at the same moment in the negative half-cycle as the drive signals of the fifth switching device, the sixth switching device, the ninth switching device, and the tenth switching device.

[0090] Embodiment 1:

[0091] Please refer to Figure 2 , this figure is Embodiment 1 of this patent. When the insulated gate bipolar transistors IGBT1, IGBT2, and IGBT4 are conducting and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 2Vdc, where Vdc represents the power supply voltage.

[0092] Embodiment 2:

[0093] Please refer to Figure 3 , this figure is Embodiment 2 of this patent. When the insulated gate bipolar transistors IGBT2 and IGBT4 are conducting and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs Vdc.

[0094] Embodiment 3:

[0095] Please refer to Figure 4 , this figure is Embodiment 3 of this patent. When the insulated gate bipolar transistors IGBT3, IGBT4, IGBT9, and IGBT10 are conducting and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 0; or when the insulated gate bipolar transistors IGBT5, IGBT6, IGBT9, and IGBT10 are conducting and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs 0.

[0096] Embodiment 4:

[0097] Please refer to Figure 5 , this figure is Embodiment 4 of this patent. When the insulated gate bipolar transistors IGBT5 and IGBT7 are conducting and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs -Vdc.

[0098] Embodiment 5:

[0099] Please refer to Figure 6 , this figure is Embodiment 5 of this patent. When the insulated gate bipolar transistors IGBT5, IGBT7, and IGBT8 are conducting and other insulated gate bipolar transistors IGBT are turned off, the circuit outputs -Vdc.

[0100] Embodiment 6:

[0101] Please refer to Figure 7 , which shows Embodiment Six of this patent. The function of the conversion circuit in this embodiment is to convert direct current into three-phase alternating current. The first terminal (1), the second terminal (2), and the third terminal (3) are the direct current input terminals, and the tenth terminal (ten), the eleventh terminal (11), and the twelfth terminal (12) are the output terminals of the three-phase alternating current. The feature of this embodiment is that a DC bus capacitor is installed in each bridge arm, and the DC bus capacitor of each phase is installed close to the bridge arm of that phase, which is beneficial to reducing the stray inductance value from the DC bus capacitor to the bridge arm and is more conducive to the stability of the system.

[0102] Embodiment Seven:

[0103] Please refer to Figure 8 , which shows Embodiment Seven of this patent. The function of the conversion circuit in this embodiment is to convert direct current into three-phase alternating current. The first terminal (1), the second terminal (2), and the third terminal (3) are the direct current input terminals, and the tenth terminal (ten), the eleventh terminal (11), and the twelfth terminal (12) are the output terminals of the three-phase alternating current. The feature of this embodiment is that all bridge arms share a DC bus capacitor, and the DC bus capacitor is installed at the input end of the DC bus, which is beneficial to reducing the number of capacitors, making the structure of the system simpler and the volume of the device smaller.

[0104] Embodiment Eight:

[0105] Please refer to Figure 9 , which shows Embodiment Eight of this patent. The function of the conversion circuit in this embodiment is to convert three-phase alternating current into direct current. The first terminal (1), the second terminal (2), and the third terminal (3) are the input terminals of the three-phase alternating current. The feature of this embodiment is that a DC bus capacitor is installed in each bridge arm, and the DC bus capacitor of each phase is installed close to the bridge arm of that phase, which is beneficial to reducing the stray inductance value from the DC bus capacitor to the bridge arm and is conducive to the stability of the system. The topological structure of this embodiment can be applied to rectifier devices, active filters, and static var compensators.

[0106] Embodiment Nine:

[0107] Please refer to Figure 10 , which shows Embodiment Nine of this patent. The function of the conversion circuit in this embodiment is to convert three-phase alternating current into direct current. The first terminal (1), the second terminal (2), and the third terminal (3) are the input terminals of the three-phase alternating current. The feature of this embodiment is that all bridge arms share a DC bus capacitor, and the DC bus capacitor is installed at the input end of the DC bus, which is beneficial to reducing the number of capacitors, making the structure of the system simpler and the volume of the device smaller. The topological structure of this embodiment can be applied to rectifier devices, active filters, and static var compensators.

[0108] Embodiment Ten:

[0109] Please refer to Figure 11 , this figure is Embodiment Ten of this patent. The function of the conversion circuit in this embodiment is to convert three-phase alternating current into three-phase alternating current. The first terminal (1), the second terminal (2), and the third terminal (3) are the input terminals of three-phase alternating current, and the tenth terminal (ten), the eleventh terminal (11), and the twelfth terminal (12) are the output terminals of three-phase alternating current. The feature of this embodiment is that a DC bus capacitor is installed in each bridge arm, and the DC bus capacitor of each phase is installed close to the bridge arm of this phase, which is beneficial to reducing the stray inductance value from the DC bus capacitor to the bridge arm and is beneficial to the stability of the system.

[0110] Embodiment Eleven:

[0111] Please refer to Figure 12 , this figure is Embodiment Eleven of this patent. The function of the conversion circuit in this embodiment is to convert three-phase alternating current into three-phase alternating current. The first terminal (1), the second terminal (2), and the third terminal (3) are the input terminals of three-phase alternating current, and the tenth terminal (ten), the eleventh terminal (11), and the twelfth terminal (12) are the output terminals of three-phase alternating current. The feature of this embodiment is that all bridge arms share a DC bus capacitor, and the DC bus capacitor is installed at the input end of the DC bus, which is beneficial to reducing the number of capacitors, making the structure of the system simpler and the volume of the device smaller.

[0112] Embodiment Twelve:

[0113] Please refer to Figure 13 , this figure is Embodiment Twelve of this patent. The comparison result of the voltage value of the sine modulation wave and the voltage value of the triangular carrier wave A at the same moment in the positive half-cycle is Q1, which serves as the drive signals for the first switch device, the second switch device, and the fourth switch device;

[0114] The comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular carrier wave A and the triangular carrier wave B at the same moment in the positive half-cycle is Q2, which serves as the drive signals for the second switch device and the fourth switch device;

[0115] The comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular carrier wave B and the triangular carrier wave C at the same moment in the positive half-cycle is Q3, which serves as the drive signals for the third switch device, the fourth switch device, the ninth switch device, and the tenth switch device.

[0116] The comparison result of the voltage value of the sine modulation wave and the voltage values of the triangular carrier wave B and the triangular carrier wave C at the same moment in the negative half-cycle is Q4, which serves as the drive signals for the fifth switch device, the sixth switch device, the ninth switch device, and the tenth switch device.

[0117] The comparison result Q5 of the voltage value of the sine modulation wave with the voltage values of triangular carrier wave A and triangular carrier wave B at the same moment in the negative half-cycle is used as the driving signal for the seventh switching device, which is the fifth switching device.

[0118] The comparison result Q6 of the voltage value of the sine modulation wave with the voltage value of triangular carrier wave A at the same moment in the half-cycle is used as the driving signals for the fifth switching device, the seventh switching device, and the eighth switching device.

Claims

1. A simplified five-level voltage source converter device, characterized in that, it includes a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4; a first terminal (1), a second terminal (2), a third terminal (3), a fourth terminal (4), a fifth terminal (5), a sixth terminal (6), a seventh terminal (7), an eighth terminal (8), a ninth terminal (9); and ten insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4, IGBT5, IGBT6, IGBT7, IGBT8, IGBT9, IGBT10; characterized in that the first capacitor C1 is connected between the first terminal (1) and the second terminal (2); the second capacitor C2 is connected between the second terminal (2) and the third terminal (3); the third capacitor C3 is connected between the fifth terminal (5) and the fourth terminal (4); the fourth capacitor C4 is connected between the fourth terminal (4) and the sixth terminal (6); the collector of IGBT1 is connected to the first terminal (1), and the emitter is connected to the fifth terminal (5); the collector of IGBT2 is connected to the fifth terminal (5), and the emitter is connected to the seventh terminal (7); the collector of IGBT3 is connected to the seventh terminal (7), and the emitter is connected to the fourth terminal (4); the collector of IGBT4 is connected to the seventh terminal (7), and the emitter is connected to the ninth terminal (9); the collector of IGBT5 is connected to the ninth terminal (9), and the emitter is connected to the eighth terminal (8); the collector of IGBT6 is connected to the fourth terminal (4), and the emitter is connected to the eighth terminal (8); the collector of IGBT7 is connected to the eighth terminal (8), and the emitter is connected to the sixth terminal (6); the collector of IGBT8 is connected to the sixth terminal (6), and the emitter is connected to the third terminal (3); the collector of IGBT9 is connected to the fourth terminal (4), and the emitter is connected to the emitter of IGBT10; the collector of IGBT10 is connected to the second terminal (2), and the emitter is connected to the emitter of IGBT9; the emitters of IGBT9 and IGBT10 are connected, and the ninth terminal is the output terminal and is connected between the emitter of IGBT4 and the collector of IGBT5; when IGBT1, IGBT2, and IGBT4 are turned on and other IGBTs are turned off, the circuit outputs 2Vdc, where Vdc represents the supply voltage; when IGBT2 and IGBT4 are turned on and other IGBTs are turned off, the circuit outputs Vdc; when IGBT3, IGBT4, IGBT9, and IGBT10 are turned on and other IGBTs are turned off, the circuit outputs 0; or when IGBT5, IGBT6, IGBT9, and IGBT10 are turned on and other IGBTs are turned off, the circuit outputs 0; when IGBT5 and IGBT7 are turned on and other IGBTs are turned off, the circuit outputs -Vdc; when IGBT5, IGBT7, and IGBT8 are turned on and other IGBTs are turned off, the circuit outputs -2Vdc.

2. A simplified five-level voltage source converter device according to claim 1, characterized in that, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4; IGBT1, IGBT2, IGBT3, IGBT4, IGBT5, IGBT6, IGBT7, IGBT8, IGBT9, IGBT10, the drive board, and the control board are integrally packaged together.

3. A simplified five-level voltage source converter device according to claim 1 or 2, characterized in that, it further includes a control unit for controlling the on-state or off-state of each IGBT in the five-level topology unit so that the converter operates in the corresponding operating state.

4. A simplified five-level voltage source converter device according to claim 3, characterized in that, the control unit is respectively connected to each IGBT, and the control unit provides drive signals for each IGBT respectively; each IGBT conducts or cuts off under the corresponding drive signal.

5. A simplified five-level voltage source converter device according to claim 4, characterized in that, the control signal of the control unit includes a sinusoidal modulation wave and three triangular carrier waves with the same frequency and amplitude, namely triangular carrier wave A, triangular carrier wave B, and triangular carrier wave C; the control unit uses the comparison result of the voltage value of the sinusoidal modulation wave and the voltage value of the triangular carrier wave A at the same moment in the positive half cycle as the drive signals of IGBT1, IGBT2, and IGBT4; the control unit uses the comparison result of the voltage value of the sinusoidal modulation wave and the voltage values of the triangular carrier wave A and the triangular carrier wave B at the same moment in the positive half cycle as the drive signals of IGBT2 and IGBT4; the control unit uses the comparison result of the voltage value of the sinusoidal modulation wave and the voltage values of the triangular carrier wave B and the triangular carrier wave C at the same moment in the positive half cycle as the drive signals of IGBT3, IGBT4, IGBT9, and IGBT10; the control unit uses the comparison result of the voltage value of the sinusoidal modulation wave and the voltage value of the triangular carrier wave A at the same moment in the negative half cycle as the drive signals of IGBT5, IGBT7, and IGBT8; the control unit uses the comparison result of the voltage value of the sinusoidal modulation wave and the voltage values of the triangular carrier wave A and the triangular carrier wave B at the same moment in the negative half cycle as the drive signals of IGBT5 and IGBT7; the control unit uses the comparison result of the voltage value of the sinusoidal modulation wave and the voltage values of the triangular carrier wave B and the triangular carrier wave C at the same moment in the negative half cycle as the drive signals of IGBT5, IGBT6, IGBT9, and IGBT10.

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