Inductor current sharing method and device of module parallel current source type converter

Abstract

The invention provides an inductor current sharing method and device for a module parallel current source type converter, and belongs to the technical field of power supply control. 2N + 1 multi-level modulation waves, a quadrature axis modulation ratio and a direct axis modulation ratio in the module parallel current source type converter are obtained; according to a given quadrature-axis modulation ratio and a given direct-axis modulation ratio, determining a sector of a given current and a switching state distributed to each module in the module parallel current source type converter; determining a total current modulation wave and a current sector corresponding to the current modulation wave according to the switching vector of the switching state; the number of switching states of each module is calculated, distribution of switching vectors of N modules is obtained after a calculation sector is given through the number of the switching states, and currents corresponding to the switching vectors are distributed to the N modules; and voltage and current of the switching vector in each module are sorted, and combined distribution is performed according to the sorting of the voltage and the current, so that current sharing of 2N inductors of the positive and negative electrodes of the direct current is realized in any modulation mode.

Description

Technical Field

[0001] The present application belongs to the field of power supply control technology, and in particular relates to an inductor current equalization method and device for a module parallel current source converter. Background Art

[0002] The schematic diagram of the multimodule current source converter (MCSC) is shown in Figure 3 As shown, N modules are connected in parallel, and each module contains two positive and negative DC output ports, each with an inductor for continuous current flow and isolation between different modules. The MCSC topology is suitable for the growing demand for high-power rectifier devices, and has the characteristics of simple structure, small size and weight, low cost, small harmonics on the AC side, controllable reactive power, small current ripple on the DC side, and precise and fast power following. However, the upper negative inductance of the module will cause uneven or even divergent current distribution due to factors such as differences in electrical parameters between modules, causing the on-current and off-current of power electronic devices to exceed the limit, damaging switching devices and other circuit components, and seriously affecting the normal operation of the device.

[0003] At present, there is limited research on current sharing control of module inductors. One of the existing technologies is to adjust the zero vector freewheeling phase between different modules so that the voltage difference between the modules is generated due to the different output levels during zero vector freewheeling, and the inductor current is adjusted to achieve current sharing. This current sharing method relies on a higher modulation frequency, and the current sharing effect is limited when the number and time of zero vectors are short.

[0004] The second prior art proposes a quasi selective harmonic elimination (Q-SHE) method in modulation, in which a narrow bypass pulse is added to the harmonic elimination modulation to make the negative inductance on the module evenly current-balanced. However, this method requires complex calculations and table lookups in advance to output the modulation signal, which is not conducive to the rapid response and precise follow-up of the system power regulation, and has a significant impact on the sinusoidality of the modulation wave when the switching frequency is low. Moreover, this method can only be applied to the parallel connection of two modules and does not support the expansion of the number of modules.

[0005] The third prior art uses voltage judgment and sorting to control the current sharing of the inductor for the MCSC-based STATCOM topology, but it can only be applied to the occasion where each module has only one load reactance, and cannot be directly applied to the MCSC where each module has two reactances. Summary of the invention

[0006] In view of the above problems, the present application proposes an inductor current equalization method, device, equipment and medium for a module parallel current source converter.

[0007] An embodiment of the present application provides, on one hand, a method for equalizing inductor current of a module parallel current source converter, comprising:

[0008] Obtaining 2N+1 multi-level modulation waves and a quadrature-axis modulation ratio and a direct-axis modulation ratio in a module parallel current source converter; the quadrature-axis modulation ratio and the direct-axis modulation ratio are given by the module parallel current source converter;

[0009] Determine the sectors of the given current and the switch states of each module in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio;

[0010] Determine the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state;

[0011] The number of switch states of each module is calculated, and the distribution of switch vectors of N modules is obtained after the calculation sector is given by the number of switch states, wherein the currents corresponding to the multiple switch vectors are distributed to the N modules;

[0012] The voltage and current of the switch vector in each module are sorted, and combined and allocated according to the sorting of voltage and current to achieve inductor current balance in each module.

[0013] Furthermore, the acquisition module parallel current source converter 2N+1 multi-level modulation waves and the modulation ratio of the quadrature axis to the direct axis includes:

[0014] A three-value switch function is set for the switch of each phase bridge arm to represent the switch vector; there are nine current vectors for a single module in the module parallel current source converter; each of the current vectors represents a switch state.

[0015] Further, the determining of the sectors of the given current and the switch states of the modules in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio comprises:

[0016] Calculating a reference current in a module-parallel current source converter according to a given quadrature-axis modulation ratio and a direct-axis modulation ratio;

[0017] A given current sector and a given current distribution to the switch states of each module in the module parallel current source converter are determined based on the reference current.

[0018] Further, the determining of the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state includes:

[0019] The switching vectors of all modules in the module parallel current source converter are superimposed to obtain the total current modulation wave.

[0020] Furthermore, the method also includes: setting the vectors of each sector to consist of two adjacent vectors to minimize the switching frequency of the device; wherein, in the cardinal sector, an upper bridge arm is always turned on, and the lower bridge arm is three-phase commutated, and in the even sector, a lower bridge arm is always turned on, and the upper bridge arm is three-phase commutated.

[0021] Furthermore, the voltage and current of the switch vector in each module are sorted, and the voltage and current are combined and allocated according to the sorting of the voltage and current to make the current flow evenly on the inductor, including:

[0022] The three-phase voltages of the multiple switch vectors in each module are sorted in ascending order; the negative inductor currents are sorted in descending order;

[0023] The reverse sequence arrangement of the three-phase voltage and the reverse sequence arrangement of the negative inductor current are combined and distributed so that the current flows evenly on the inductor.

[0024] Further, the method further comprises: determining the voltage on the inductor according to the differential of the current on the inductor;

[0025] according to is the output potential of the bridge arm, u dc+ is the positive potential of the DC port, u dc- is the negative potential of the DC port;

[0026] and i L The reverse order makes the inductance of the current participating in the current sharing from small to large at each moment to large to small. Realize the current sharing of the inductor.

[0027] Based on the same inventive concept, the embodiment of the present application also provides an inductor current balancing device for a module parallel current source converter, comprising:

[0028] An acquisition unit, used for acquiring 2N+1 multi-level modulation waves and a quadrature-axis modulation ratio and a direct-axis modulation ratio in a module parallel current source converter; the quadrature-axis modulation ratio and the direct-axis modulation ratio are given by the module parallel current source converter;

[0029] A distribution unit, used for determining the sectors of a given current and the switch states of each module in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio;

[0030] A determination unit, used to determine the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state;

[0031] A calculation unit, used for calculating the number of switch states of each module, and obtaining the distribution of switch vectors of N modules after the calculation sector is given by the number of switch states, wherein currents corresponding to the multiple switch vectors are distributed to the N modules;

[0032] The current balancing unit is used to sort the voltage and current of the switch vector in each module, and to combine and distribute them according to the sorting of voltage and current to achieve inductor current balancing of each module.

[0033] Based on the same inventive concept, another aspect of the embodiment of the present application further provides an electronic device, comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0034] a memory storing a computer program;

[0035] The processor implements the inductor current sharing method of the module parallel current source converter when executing the program stored in the memory.

[0036] Based on the same inventive concept, on the other hand, an embodiment of the present application further provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the inductor current sharing method of the module parallel current source converter.

[0037] This application has at least one of the following beneficial effects:

[0038] 1. It can be applied to any modulation mode. It only needs to provide multi-level modulation waves to reasonably distribute the switch mode among N modules to achieve current sharing of 2N inductors at the positive and negative poles of the DC end;

[0039] 2. Not limited by the number of modules, and can support the expansion of any number of modules;

[0040] 3. To achieve inductor current sharing, no complicated calculation is required. Only simple sampling and judgment of the capacitor input voltage on the three-phase AC side is required.

[0041] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures indicated in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a flow chart of an inductor current sharing method of a module parallel current source converter in an embodiment of the present application;

[0044] Figure 2 A schematic diagram of an inductor current balancing device of a module parallel current source converter in an embodiment of the present application;

[0045] Figure 3 This is a schematic diagram of a module parallel current source converter in the prior art of this application;

[0046] Figure 4 A schematic diagram of a switch vector of a single parallel current source converter module in an embodiment of the present application;

[0047] Figure 5 A schematic diagram of the current modulation wave and corresponding sectors of the parallel current source converter module in the embodiment of the present application;

[0048] Figure 6 This is a schematic diagram of the inductor current sharing process of the parallel current source converter in the embodiment of the present application;

[0049] Figure 7 This is a waveform diagram of the inductor current in a three-module parallel current source converter in an embodiment of the present application when the current sharing strategy is not enabled for 1s to 2s;

[0050] Figure 8 This is a schematic diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] It should be noted that the terms "first", "second" etc. in the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged in appropriate circumstances, so that the embodiments of the present application described here. In the present application, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" etc. are based on the orientation or positional relationship shown in the accompanying drawings.

[0053] On the one hand, the present application provides an inductor current balancing method for a module parallel current source converter, see Figure 1 ,include:

[0054] S101: Obtain 2N+1 multi-level modulation waves and a quadrature-axis modulation ratio and a direct-axis modulation ratio in a module parallel current source converter; the quadrature-axis modulation ratio and the direct-axis modulation ratio are given by the module parallel current source converter;

[0055] S102: determining the sectors of the given current and the switch states of the modules in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio;

[0056] S103: determining the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state;

[0057] S104: Calculate the number of switch states of each module, and obtain the distribution of switch vectors of N modules after giving the calculation sector by the number of switch states, wherein the currents corresponding to the multiple switch vectors are distributed to the N modules;

[0058] S105: sorting the voltage and current of the switch vector in each module, and performing combined allocation according to the sorting of the voltage and current to achieve inductor current balancing of each module.

[0059] This application is based on the prior art Figure 3 The modules in the current source converter are connected in parallel to share the inductor current.

[0060] In step S101, the acquisition module parallel current source converter 2N+1 multi-level modulation waves and the modulation ratio of the quadrature axis to the direct axis includes:

[0061] A three-value switch function is set for the switch of each phase bridge arm to represent the switch vector; there are nine current vectors for a single module in the module parallel current source converter; each of the current vectors represents a switch state.

[0062] Specifically, in the current source converter, a three-value switch function 1 / 0 / -1 is set for the switch of each phase bridge arm to represent the switch vector, 1 means the upper bridge arm is turned on and the lower bridge arm is turned off; -1 means the lower bridge arm is turned on and the upper bridge arm is turned off; 0 means the upper and lower bridge arms are turned on at the same time for short-circuit freewheeling or turned off at the same time for a single module. Figure 4 There are nine current vectors shown, among which I 7 (0,0,0) A , I 8 (0,0,0) B , I 9 (0,0,0) C They represent the direct-flow and freewheeling of the three phases A, B, and C respectively, and each current vector represents a switching state.

[0063] In step S102, see Figure 5 The method of determining the sectors of a given current and distributing the current sectors to the switch states of each module in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio comprises:

[0064] Calculating a reference current in a module-parallel current source converter according to a given quadrature-axis modulation ratio and a direct-axis modulation ratio;

[0065] A given current sector and a given current distribution to the switch states of each module in the module parallel current source converter are determined based on the reference current.

[0066] Specifically, in the MCSC of N modules, the controller will output a 2N+1 level multi-level modulation wave and the modulation ratio of the d and q axes. For the modulation wave, we need to substitute the given modulation ratio into the formula

[0067]

[0068] The reference current is obtained to determine the sector of the given current so as to reasonably allocate the switching status of each module.

[0069] Among them, M d Represents the quadrature axis component; M q represents the direct axis component, e j θ represents the corresponding sector.

[0070] In step S103, determining the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state includes:

[0071] The switching vectors of all modules in the module parallel current source converter are superimposed to obtain the total current modulation wave.

[0072] In some embodiments, the method further includes: setting the vectors of each sector to be composed of two adjacent vectors to minimize the switching frequency of the device; wherein, in the cardinal sector, one upper bridge arm is always turned on, and the lower bridge arm is three-phase commutated, and in the even sector, one lower bridge arm is always turned on, and the upper bridge arm is three-phase commutated. 6 (1,-1,0), I 1 (1,0,-1) and I 7 (0,0,0), the upper bridge arm of phase A is always on, and the switching action of the lower bridge arm of the three phases realizes the switching and combination of vectors. It can support the expansion of any number of modules.

[0073] In step S105, the voltage and current of the switch vector in each module are sorted, and combined and allocated according to the sorting of the voltage and current to achieve inductor current balancing of each module, including:

[0074] The three-phase voltages of the multiple switch vectors in each module are sorted in ascending order; the negative inductor currents are sorted in descending order;

[0075] The reverse sequence arrangement of the three-phase voltage and the reverse sequence arrangement of the negative inductor current are combined and distributed so that the current flows evenly on the inductor.

[0076] Specifically, the next step after obtaining the current sector is to calculate the number of each switching state, (i am ,i bm ,i cm ) is given and the sectors are calculated, the distribution of N module switch vectors can be calculated. For example, if (i am ,i bm ,i cm ) is in sector I, then equation (2) is satisfied

[0077]

[0078] Expressed in matrix form:

[0079]

[0080] The n obtained by calculating formula (3) is 6 ,n 1 ,n 7 is the number of three vectors that make up this modulated wave,

[0081] The next step is to convert n 6 Personal I 6 , n 1 Personal I 1 , n 7 Personal I 7 Distributed into N modules, that is, n6 The lower bridge arm of the B phase of the module is opened, n 1 The lower bridge arm of phase C of each module is opened, n 7 The lower bridge arm of phase A of each module is turned on, and the upper bridge arm of phase A of all modules is turned on. Therefore, it can be applied to any modulation mode. It only needs to provide a multi-level modulation wave to reasonably distribute the switching mode among N modules to achieve the current sharing of 2N inductors at the positive and negative poles of the DC end.

[0082] Then, in this distribution process, the current sharing of the negative inductor is achieved by the following method:

[0083] n 6 u Cb , n 1 u Cc , n 7 u Ca Arrange in ascending order from small to large, and put the negative inductor current i l1n ,i l2n …i lNn Arrange them in descending order from large to small, and then combine and distribute the two reverse-order sequences, thereby ensuring that the maximum voltage is applied to the inductor with the smallest current.

[0084] The method further includes: determining a voltage across the inductor based on a differential of a current across the inductor;

[0085] according to is the output potential of the bridge arm, u dc+ is the positive potential of the DC port, u dc- is the negative potential of the DC port;

[0086] and i L The reverse order makes the inductance of the current participating in the current sharing from small to large at each moment to large to small. Realize the current sharing of the inductor.

[0087] See also Figure 6 , if (i am ,i bm ,i cm ) In other sectors, different vector distribution expressions similar to (3) can be obtained by the same logic. Similarly, the three-phase capacitor voltage and inductor current are arranged in reverse order. For example, in sector II, the lower bridge arm of phase C of all modules is always turned on, and the upper bridge arms of phases A, B, and C are turned on in the modules respectively. After calculation, the output u of the upper bridge arm is reasonably distributed. Ca ,u Cb ,u CcThe current and output voltage of the positive inductor are arranged in reverse order to achieve current sharing of the positive inductor. Similarly, the negative inductor of sector III is current shared, the positive inductor of sector IV is current shared, the negative inductor of sector V is current shared, and the positive inductor of sector VI is current shared.

[0088] The implementation method in this application is based on MATLAB simulation. A simulation model of a three-module MCSC is built in MATLAB / Simulink. The total output current is controlled to be 8400A, and the average current in each module is about 2800A.

[0089] In the simulation model, current sharing control is disabled for 1s to 2s and enabled for the rest of the time. Figure 7 It can be seen from the positive and negative inductor currents of the three modules shown in the simulation waveform that the module current diverges when the current sharing control is not enabled in 1s, and the circuit quickly reaches and maintains the average current of 2800A when the current sharing control is re-enabled in 2s. Therefore, it is verified that the current sharing control strategy proposed in this patent can strictly control the current balance of the 2N inductors between the N modules in the MCSC, achieving the expected control effect.

[0090] Based on the same inventive concept, the present application also provides an inductor current balancing device for a module parallel current source converter, see Figure 2 ,include:

[0091] An acquisition unit 201 is used to acquire 2N+1 multi-level modulation waves and a quadrature-axis modulation ratio and a direct-axis modulation ratio in a module parallel current source converter; the quadrature-axis modulation ratio and the direct-axis modulation ratio are given by the module parallel current source converter;

[0092] The allocation unit 202 is used to determine the sectors of the given current and the switch states of each module in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio;

[0093] A determination unit, used to determine the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state;

[0094] The calculation unit 203 is used to calculate the number of switch states of each module, and obtain the distribution of the switch vectors of the N modules after the calculation sector is given by the number of switch states, wherein the currents corresponding to the multiple switch vectors are distributed to the N modules;

[0095] The current balancing unit 204 is used to sort the voltage and current of the switch vector in each module, and to perform combined distribution according to the sorting of the voltage and current, so as to achieve inductor current balancing of each module.

[0096] The present application obtains 2N+1 multi-level modulation waves and quadrature-axis modulation ratio and direct-axis modulation ratio in a module parallel current source converter; the quadrature-axis modulation ratio and direct-axis modulation ratio are given by the module parallel current source converter; the sector of a given current and the switch state allocated to each module in the module parallel current source converter are determined according to the given quadrature-axis modulation ratio and direct-axis modulation ratio; the current sector corresponding to the total current modulation wave and the current modulation wave is determined according to the switch vector of the switch state; the number of switch states of each module is calculated, and the distribution of the switch vectors of N modules is obtained after the calculation sector is given by the number of switch states, wherein the currents corresponding to the multiple switch vectors are allocated to the N modules; the voltage and current of the switch vector in each module are sorted, and combined and allocated according to the sorting of the voltage and current to achieve inductor current balancing of each module.

[0097] At least one of the following beneficial effects:

[0098] 1. It can be applied to any modulation mode. It only needs to provide multi-level modulation waves to reasonably distribute the switch mode among N modules to achieve current sharing of 2N inductors at the positive and negative poles of the DC end;

[0099] 2. Not limited by the number of modules, and can support the expansion of any number of modules;

[0100] 3. To achieve inductor current sharing, no complicated calculation is required. Only simple sampling and judgment of the capacitor input voltage on the three-phase AC side is required.

[0101] Based on the same inventive concept, the present application embodiment also provides an electronic device 161, see Figure 8 , including a processor 164, a communication interface 165, a memory 162 and a communication bus, wherein the processor 164, the communication interface 165 and the memory 162 communicate with each other through the communication bus;

[0102] A memory 162 storing a computer program 163;

[0103] When the processor 164 executes the program stored in the memory 162, the inductor current sharing method of the module parallel current source converter is implemented.

[0104] The above communication bus may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus may be divided into an address bus, a data bus, a control bus, etc.

[0105] The communication interface 165 is used for communication between the electronic device 161 and other devices.

[0106] The memory 162 may include a random access memory 162 (RAM), or may include a non-volatile memory 162 (non-volatile memory), such as at least one disk memory 162. Optionally, the memory 162 may also be at least one storage device located away from the processor 164.

[0107] The above-mentioned processor 164 can be a general-purpose processor 164, including a central processing unit 164 (CPU), a network processor 164 (NP), etc.; it can also be a digital signal processor 164 (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0108] Based on the same inventive concept, the embodiment of the present application further provides a computer-readable storage medium storing a computer program 163, which implements an inductor current sharing method of a module parallel current source converter when executed by a processor 164.

[0109] The computer-readable storage medium may be included in the device / apparatus described in the above embodiment; or it may exist independently without being assembled into the device / apparatus. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the inductor current sharing method of the module parallel current source converter according to the embodiment of the present application is implemented.

[0110] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for equalizing inductor current of a module parallel current source converter, characterized in that: include: Obtaining 2N+1 multi-level modulation waves and a quadrature-axis modulation ratio and a direct-axis modulation ratio in a module parallel current source converter; the quadrature-axis modulation ratio and the direct-axis modulation ratio are given by the module parallel current source converter; Determine the sectors of the given current and the switch states of each module in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio; Determine the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state; The number of switch states of each module is calculated, and the distribution of switch vectors of N modules is obtained after the calculation sector is given by the number of switch states, wherein the currents corresponding to the multiple switch vectors are distributed to the N modules; The voltage and current of the switch vector in each module are sorted, and the voltage and current are combined and allocated according to the sorting, so that the current flows evenly on the inductor.

2. The method according to claim 1, characterized in that The acquisition module parallel current source converter 2N+1 multi-level modulation waves and the modulation ratio of the quadrature axis to the direct axis includes: A three-value switch function is set for the switch of each phase bridge arm to represent the switch vector; there are nine current vectors for a single module in the module parallel current source converter; each of the current vectors represents a switch state.

3. The method according to claim 1 or 2, characterized in that: The method of determining the sectors of a given current and distributing the sectors to the switch states of each module in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio comprises: Calculating a reference current in a module-parallel current source converter according to a given quadrature-axis modulation ratio and a direct-axis modulation ratio; A given current sector and a given current distribution to the switch states of each module in the module parallel current source converter are determined based on the reference current.

4. The method according to claim 3, characterized in that The method of determining the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state includes: The switching vectors of all modules in the module parallel current source converter are superimposed to obtain the total current modulation wave.

5. The method according to claim 4, characterized in that The method further comprises: The vectors of each sector are set to consist of two adjacent vectors to minimize the switching frequency of the device; in the cardinal sector, an upper bridge arm is always turned on and the lower bridge arm is three-phase commutated, and in the even sector, a lower bridge arm is always turned on and the upper bridge arm is three-phase commutated.

6. The method according to claim 1, characterized in that The voltage and current of the switch vector in each module are sorted, and the voltage and current are combined and distributed according to the sorting of the voltage and current, so that the current flows evenly on the inductor, including: The three-phase voltages of the multiple switch vectors in each module are sorted in ascending order; the negative inductor currents are sorted in descending order; The reverse sequence arrangement of the three-phase voltage and the reverse sequence arrangement of the negative inductor current are combined and distributed so that the current flows evenly on the inductor.

7. The method according to claim 6, characterized in that The method further includes: determining a voltage across the inductor based on a differential of a current across the inductor; according to is the output potential of the bridge arm, u d c+ is the positive potential of the DC port, u d c- is the negative potential of the DC port; and i L The reverse order makes the inductance of the current participating in the current sharing from small to large at each moment to large to small. Realize the current sharing of the inductor.

8. An inductor current balancing device for a module parallel current source converter, characterized in that: include: An acquisition unit, used for acquiring 2N+1 multi-level modulation waves and a quadrature-axis modulation ratio and a direct-axis modulation ratio in a module parallel current source converter; the quadrature-axis modulation ratio and the direct-axis modulation ratio are given by the module parallel current source converter; A distribution unit, used for determining the sectors of a given current and the switch states of each module in the module parallel current source converter according to the given quadrature-axis modulation ratio and the direct-axis modulation ratio; A determination unit, used to determine the total current modulation wave and the current sector corresponding to the current modulation wave according to the switching vector of the switching state; A calculation unit, used for calculating the number of switch states of each module, and obtaining the distribution of switch vectors of N modules after the calculation sector is given by the number of switch states, wherein currents corresponding to the multiple switch vectors are distributed to the N modules; The current balancing unit is used to sort the voltage and current of the switch vector in each module, and to combine and distribute the voltage and current according to the sorting, so as to balance the current on the inductor.

9. An electronic device, characterized in that: include: A processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a memory storing a computer program; The processor, when executing the program stored in the memory, implements the inductor current sharing method of the module parallel current source converter described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, the inductor current sharing method of the module parallel current source converter described in any one of claims 1 to 7 is implemented.

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