High-voltage high-power power electronic device and control method thereof

Abstract

The invention relates to a high-voltage high-power power electronic device and a control method thereof. The high-voltage high-power power electronic device comprises a controller and a bridge arm unit connected with a power grid alternating current bus, the bridge arm unit comprises at least one group of bridge arms; each group of bridge arms comprises an alternating current reactor, an upper bridge arm and a lower bridge arm; each of the upper bridge arm and the lower bridge arm comprises a plurality of sub-modules; the upper bridge arm is connected with the lower bridge arm; one end of the AC reactor is connected with a power grid AC bus, and the other end is connected with a connection point between the upper bridge arm and the lower bridge arm; the controller is used for controlling each sub-module by adopting a step switching modulation strategy so as to control the potential to ground of a target end point of the alternating current reactor; wherein the target end point is one end of the alternating current reactor connected with the connection point between the upper bridge arm and the lower bridge arm. According to the invention, the problem of unbalanced series voltage is solved, the capacitance value of a sub-module capacitor is greatly reduced by innovating a modulation strategy, the volume and the weight of the device are reduced, and the voltage stress of the alternating current side is greatly reduced by adopting a step switching modulation mode.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronics, and in particular relates to a high-voltage and high-power power electronic device and a control method thereof. Background Art

[0002] With the advancement of power electronics device technology and its applications, device voltages and capacities are increasing. For example, in scenarios like DC transmission, flexible power distribution, high-voltage wind power, high-voltage frequency conversion, and rail transit, device voltages often reach several kV or even higher. Due to device voltage limitations, the current maximum voltage of mature IGBTs is only 6.5 kV. Therefore, a series or cascade topology is needed to address this issue.

[0003] There are two main types of high-voltage, high-power power electronic topologies. One is based on the direct series connection of IGBTs and adopts the SPWM modulation strategy. This solution has a simple topology and low cost, but the voltage balancing control of the IGBT series is difficult and the switch dv / dt voltage stress is large. The other is a modular multi-level technology route that uses modulation measurement such as sinusoidal wave approximation. This solution makes voltage balancing control easy, but the device is large in size and weight, and the cost is high. Summary of the Invention

[0004] In order to overcome the problems existing in the above-mentioned related technologies, the present invention provides a high-voltage and high-power power electronic device and a control method thereof.

[0005] According to a first aspect of an embodiment of the present invention, a high-voltage, high-power power electronic device is provided, comprising: a controller, and a bridge arm unit connected to an AC busbar of a power grid; the bridge arm unit comprises: at least one group of bridge arms; each group of bridge arms comprises: an AC reactor, an upper bridge arm, and a lower bridge arm; the upper bridge arm and the lower bridge arm each comprise: a plurality of submodules;

[0006] The upper bridge arm and the lower bridge arm are connected; one end of the AC reactance is connected to the AC busbar of the power grid, and the other end is connected to the connection point between the upper bridge arm and the lower bridge arm;

[0007] The controller is configured to control each of the submodules using a step-switching modulation strategy, thereby controlling the ground potential of the target endpoint of the AC reactance;

[0008] The target endpoint is one end of the AC reactance connected to the connection point between the upper bridge arm and the lower bridge arm.

[0009] Preferably, the upper bridge arm comprises: a first submodule, a second submodule and a third submodule connected in series in sequence; the lower bridge arm comprises: a fourth submodule, a fifth submodule and a sixth submodule connected in series in sequence;

[0010] The third submodule is connected to the fourth submodule, and a connection point between the third submodule and the fourth submodule is connected to the other end of the AC reactance.

[0011] Preferably, each submodule includes: an upper tube, a lower tube and a capacitor; the upper tube includes: a first IGBT and a first diode; the lower tube includes: a second IGBT and a second diode;

[0012] The collector of the first IGBT is connected to the anode of the first diode, and the emitter of the first IGBT is connected to the cathode of the first diode;

[0013] The collector of the second IGBT is connected to the anode of the second diode, and the emitter of the second IGBT is connected to the cathode of the second diode;

[0014] The emitter of the first IGBT is connected to the collector of the second IGBT;

[0015] One end of the capacitor is connected to a connection point between the collector of the first IGBT and the anode of the first diode, and the other end is connected to a second connection point;

[0016] The connection point between the emitter of the first IGBT and the collector of the second IGBT is the first connection point; the connection point between the emitter of the second IGBT and the cathode of the second diode is the second connection point.

[0017] Preferably, the first connection points of the first submodules are connected to each other and then to the positive pole of the DC bus;

[0018] The second connection point of the first submodule is connected to the first connection point of the second submodule;

[0019] The second connection point of the second submodule is connected to the first connection point of the third submodule;

[0020] The second connection point of the third submodule is connected to the first connection point of the fourth submodule;

[0021] The second connection point of the fourth submodule is connected to the first connection point of the fifth submodule;

[0022] The second connection point of the fifth submodule is connected to the first connection point of the sixth submodule;

[0023] The second connection points of the sixth submodules are connected to each other and then to the negative pole of the DC bus;

[0024] A connection point between the second connection point of the third submodule and the first connection point of the fourth submodule is connected to the other end of the AC reactance.

[0025] Preferably, the bridge arm unit is a half bridge; the half bridge includes: a group of bridge arms.

[0026] Preferably, the bridge arm unit is an H-bridge; the H-bridge includes: two groups of bridge arms.

[0027] Preferably, the bridge arm unit is a three-phase bridge; the three-phase bridge includes: three groups of bridge arms.

[0028] Preferably, the controller includes:

[0029] A control unit is used to control the on / off of the first IGBT and the second IGBT in each of the submodules based on an SPWM modulation method and a step-switching modulation strategy, thereby controlling the ground potential of the target endpoint of the AC reactance.

[0030] Preferably, the control unit includes:

[0031] A division module, configured to divide each preset modulation cycle into four phases, wherein the four phases include: a first time period, a second time period, a third time period, and a fourth time period;

[0032] a first control module, configured to control, within a first time period, the first IGBTs of the submodules in the upper bridge arm to be simultaneously locked, control the second IGBTs of the submodules in the upper bridge arm to be simultaneously turned on, control the first IGBTs of the submodules in the lower bridge arm to be simultaneously turned on, and control the second IGBTs of the submodules in the lower bridge arm to be simultaneously locked, so that the ground potential of the target endpoint is a high potential;

[0033] a second control module, configured to control, within a second time period, the first IGBTs of the submodules in the upper bridge arm to be turned on sequentially according to a first preset sequence, control the second IGBTs of the submodules in the upper bridge arm to be blocked sequentially according to a second preset sequence, control the first IGBTs of the submodules in the lower bridge arm to be blocked sequentially according to a third preset sequence, and control the second IGBTs of the submodules in the lower bridge arm to be turned on sequentially according to a fourth preset sequence, so that the ground potential of the target endpoint changes from a high potential to a low potential;

[0034] a third control module, configured to control, within a third time period, the first IGBTs of the submodules in the upper bridge arm to be turned on simultaneously, control the second IGBTs of the submodules in the upper bridge arm to be blocked simultaneously, control the first IGBTs of the submodules in the lower bridge arm to be blocked simultaneously, and control the second IGBTs of the submodules in the lower bridge arm to be turned on simultaneously, so that the ground potential of the target endpoint is low;

[0035] The fourth control module is used to control the first IGBT of each sub-module in the upper bridge arm to be locked in sequence according to the fifth preset order, control the second IGBT of each sub-module in the upper bridge arm to be turned on in sequence according to the sixth preset order, control the first IGBT of each sub-module in the lower bridge arm to be turned on in sequence according to the seventh preset order, and control the second IGBT of each sub-module in the lower bridge arm to be locked in sequence according to the eighth preset order, so that the ground potential of the target endpoint changes from a low potential to a high potential.

[0036] Preferably, the SPWM modulation method is: a two-level SPWM modulation method, a three-level SPWM modulation method, or a multi-level SPWM modulation method.

[0037] According to a second aspect of an embodiment of the present invention, a control method for a high-voltage, high-power power electronic device is provided, which is applied to the high-voltage, high-power power electronic device, and includes:

[0038] A step-switching modulation strategy is adopted to control each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance.

[0039] Preferably, the modulation strategy using step switching to control each submodule, and thus controlling the ground potential of the target endpoint of the AC reactance, includes:

[0040] Based on the SPWM modulation method, a step-switching modulation strategy is adopted to control the on / off switching of the first IGBT and the second IGBT in each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance.

[0041] Preferably, the SPWM modulation method adopts a step-switching modulation strategy to control the on / off switching of the first IGBT and the second IGBT in each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance, including:

[0042] Dividing each preset modulation cycle into four stages, the four stages comprising: a first time period, a second time period, a third time period and a fourth time period;

[0043] During a first time period, the first IGBTs of each submodule in the upper bridge arm are controlled to be simultaneously locked, the second IGBTs of each submodule in the upper bridge arm are controlled to be simultaneously turned on, the first IGBTs of each submodule in the lower bridge arm are controlled to be simultaneously turned on, and the second IGBTs of each submodule in the lower bridge arm are controlled to be simultaneously locked, so that the ground potential of the target endpoint is a high potential;

[0044] During a second time period, the first IGBTs of the submodules in the upper bridge arm are controlled to be turned on in sequence according to a first preset sequence, the second IGBTs of the submodules in the upper bridge arm are controlled to be blocked in sequence according to a second preset sequence, the first IGBTs of the submodules in the lower bridge arm are controlled to be blocked in sequence according to a third preset sequence, and the second IGBTs of the submodules in the lower bridge arm are controlled to be turned on in sequence according to a fourth preset sequence, so that the ground potential of the target endpoint changes from a high potential to a low potential;

[0045] In a third time period, the first IGBTs of each submodule in the upper bridge arm are controlled to be turned on simultaneously, the second IGBTs of each submodule in the upper bridge arm are controlled to be blocked simultaneously, the first IGBTs of each submodule in the lower bridge arm are controlled to be blocked simultaneously, and the second IGBTs of each submodule in the lower bridge arm are controlled to be turned on simultaneously, so that the ground potential of the target endpoint is low;

[0046] During the fourth time period, the first IGBT of each sub-module in the upper bridge arm is controlled to be locked in sequence according to the fifth preset order, the second IGBT of each sub-module in the upper bridge arm is controlled to be turned on in sequence according to the sixth preset order, the first IGBT of each sub-module in the lower bridge arm is controlled to be turned on in sequence according to the seventh preset order, and the second IGBT of each sub-module in the lower bridge arm is controlled to be locked in sequence according to the eighth preset order, so that the ground potential of the target endpoint changes from a low potential to a high potential.

[0047] Preferably, the SPWM modulation method is: a two-level SPWM modulation method, a three-level SPWM modulation method, or a multi-level SPWM modulation method.

[0048] According to a third aspect of an embodiment of the present invention, there is provided an electronic device, comprising: at least one processor and a memory; the memory and the processor are connected via a bus;

[0049] The memory is used to store one or more programs;

[0050] When the one or more programs are executed by the at least one processor, the control method of the high-voltage and high-power power electronic device is implemented.

[0051] According to a fourth aspect of an embodiment of the present invention, a readable storage medium is provided, on which an execution program is stored. When the execution program is executed, the control method of the high-voltage and high-power power electronic device is implemented.

[0052] The technical solution provided by the present invention has the following beneficial effects:

[0053] The present invention provides a high-voltage, high-power power electronic device and a control method thereof, comprising: a controller, and a bridge arm unit connected to an AC busbar of a power grid; the bridge arm unit comprising: at least one group of bridge arms; each group of bridge arms comprising: an AC reactance, an upper bridge arm, and a lower bridge arm; the upper bridge arm and the lower bridge arm each comprising: a plurality of submodules; the upper bridge arm and the lower bridge arm are connected; one end of the AC reactance is connected to the AC busbar of the power grid, and the other end is connected to the connection point between the upper bridge arm and the lower bridge arm; the controller is configured to control each submodule using a step-switching modulation strategy to thereby control the ground potential of a target endpoint of the AC reactance; wherein the target endpoint is one end of the AC reactance connected to the connection point between the upper bridge arm and the lower bridge arm. Compared with two-level series technology, the present invention solves the problem of series voltage imbalance by connecting submodules in series; compared with modular multi-level technology, the invention significantly reduces the capacitance of the submodules and reduces the size and weight of the device through an innovative modulation strategy; and the step-switching modulation method significantly reduces the voltage stress on the AC side. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0055] Figure 1 This is a structural block diagram of a high-voltage, high-power power electronic device provided by an embodiment of the present invention;

[0056] Figure 2 is a schematic diagram of a half-bridge topology provided by an embodiment of the present invention;

[0057] Figure 3 Schematic diagram of an H-bridge topology provided by an embodiment of the present invention;

[0058] Figure 4 is a schematic diagram of a three-phase bridge topology provided by an embodiment of the present invention;

[0059] Figure 5 is a schematic diagram of the internal circuit of the submodule provided by an embodiment of the present invention;

[0060] Figure 6: is a waveform diagram of a two-level SPWM modulation method provided by an embodiment of the present invention;

[0061] Figure 7 : is a waveform diagram of a three-level SPWM modulation method provided by an embodiment of the present invention;

[0062] Figure 8 : is a waveform diagram of the multi-level SPWM modulation method provided by an embodiment of the present invention;

[0063] Figure 9 This is a structural block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0064] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the following embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0065] Example 1

[0066] The present invention provides a high-voltage and high-power power electronic device, such as Figure 1 As shown, it includes: a controller, and a bridge arm unit connected to the AC busbar of the power grid; the bridge arm unit includes: at least one group of bridge arms; each group of bridge arms includes: an AC reactor, an upper bridge arm and a lower bridge arm; the upper bridge arm and the lower bridge arm each include: multiple submodules;

[0067] The upper bridge arm and the lower bridge arm are connected; one end of the AC reactor is connected to the AC busbar of the power grid, and the other end is connected to the connection point between the upper bridge arm and the lower bridge arm;

[0068] A controller for controlling each submodule using a step-switching modulation strategy, thereby controlling the ground potential of a target endpoint of the AC reactance;

[0069] The target endpoint is one end of the AC reactance connected to the connection point between the upper bridge arm and the lower bridge arm.

[0070] Further, such as Figure 2-Figure 4 As shown, the upper bridge arm includes: a first submodule, a second submodule and a third submodule connected in series in sequence; the lower bridge arm includes: a fourth submodule, a fifth submodule and a sixth submodule connected in series in sequence;

[0071] The third submodule is connected to the fourth submodule, and a connection point between the third submodule and the fourth submodule is connected to the other end of the AC reactance.

[0072] Further Figure 5As shown, each submodule includes: an upper tube, a lower tube and a capacitor; the upper tube includes: a first IGBT and a first diode; the lower tube includes: a second IGBT and a second diode;

[0073] The collector of the first IGBT is connected to the anode of the first diode, and the emitter of the first IGBT is connected to the cathode of the first diode;

[0074] The collector of the second IGBT is connected to the anode of the second diode, and the emitter of the second IGBT is connected to the cathode of the second diode;

[0075] The emitter of the first IGBT is connected to the collector of the second IGBT;

[0076] One end of the capacitor is connected to a connection point between the collector of the first IGBT and the anode of the first diode, and the other end is connected to the second connection point;

[0077] The connection point between the emitter of the first IGBT and the collector of the second IGBT is the first connection point; the connection point between the emitter of the second IGBT and the cathode of the second diode is the second connection point.

[0078] Further, such as Figure 2-Figure 4 As shown, the first connection points of the first submodules are connected to each other and then to the positive pole of the DC bus;

[0079] The second connection point of the first submodule is connected to the first connection point of the second submodule;

[0080] The second connection point of the second submodule is connected to the first connection point of the third submodule;

[0081] The second connection point of the third submodule is connected to the first connection point of the fourth submodule;

[0082] The second connection point of the fourth submodule is connected to the first connection point of the fifth submodule;

[0083] The second connection point of the fifth submodule is connected to the first connection point of the sixth submodule;

[0084] The second connection points of the sixth submodules are connected to each other and then to the negative pole of the DC bus;

[0085] A connection point between the second connection point of the third submodule and the first connection point of the fourth submodule is connected to the other end of the AC reactance.

[0086] Further, such as Figure 2 As shown, the bridge arm unit can be but is not limited to a half bridge; the half bridge includes: a group of bridge arms.

[0087] Further, such as Figure 3As shown, the bridge arm unit can be but is not limited to an H bridge; the H bridge includes: two groups of bridge arms.

[0088] Further, such as Figure 4 As shown, the bridge arm unit can be but is not limited to a three-phase bridge; the three-phase bridge includes: three groups of bridge arms.

[0089] Furthermore, the controller includes:

[0090] The control unit is used to control the on / off of the first IGBT and the second IGBT in each submodule based on the SPWM modulation method and a step-switching modulation strategy, thereby controlling the ground potential of the target terminal of the AC reactance.

[0091] It should be noted that the ground potential of the target endpoint is the potential difference between the target endpoint and the negative pole of the DC bus, and is also the potential difference between the target endpoint and the second connection point of the sixth submodule.

[0092] It is understandable that the controller is connected to the first IGBT and the second IGBT in all sub-modules, so as to control the turning on and off of the first IGBT and the second IGBT.

[0093] Furthermore, the control unit includes:

[0094] A division module, configured to divide each preset modulation cycle into four phases, the four phases comprising: a first time period, a second time period, a third time period, and a fourth time period;

[0095] a first control module, configured to control, within a first time period, the first IGBTs of each submodule in the upper bridge arm to be simultaneously locked, control the second IGBTs of each submodule in the upper bridge arm to be simultaneously turned on, control the first IGBTs of each submodule in the lower bridge arm to be simultaneously turned on, and control the second IGBTs of each submodule in the lower bridge arm to be simultaneously locked, so that the ground potential of the target endpoint is a high potential;

[0096] a second control module, configured to control, within a second time period, the first IGBTs of each submodule in the upper bridge arm to be turned on sequentially according to a first preset sequence, control the second IGBTs of each submodule in the upper bridge arm to be blocked sequentially according to a second preset sequence, control the first IGBTs of each submodule in the lower bridge arm to be blocked sequentially according to a third preset sequence, and control the second IGBTs of each submodule in the lower bridge arm to be turned on sequentially according to a fourth preset sequence, so that the ground potential of the target endpoint changes from a high potential to a low potential;

[0097] a third control module, configured to control, within a third time period, the first IGBTs of each submodule in the upper bridge arm to be turned on simultaneously, control the second IGBTs of each submodule in the upper bridge arm to be blocked simultaneously, control the first IGBTs of each submodule in the lower bridge arm to be blocked simultaneously, and control the second IGBTs of each submodule in the lower bridge arm to be turned on simultaneously, so that the ground potential of the target endpoint is low;

[0098] The fourth control module is used to control the first IGBT of each sub-module in the upper bridge arm to be locked in sequence according to the fifth preset order, control the second IGBT of each sub-module in the upper bridge arm to be turned on in sequence according to the sixth preset order, control the first IGBT of each sub-module in the lower bridge arm to be turned on in sequence according to the seventh preset order, and control the second IGBT of each sub-module in the lower bridge arm to be locked in sequence according to the eighth preset order, so that the ground potential of the target endpoint changes from a low potential to a high potential.

[0099] It should be noted that the present invention does not limit "each preset modulation cycle", "first preset order", "second preset order", "third preset order", "fourth preset order", "fifth preset order", "sixth preset order", "seventh preset order" and "eighth preset order", and can be set by those skilled in the art based on experimental data, engineering needs or expert experience.

[0100] It can be understood that the purpose of setting all the preset sequences is to prevent the first IGBT and the second IGBT in all sub-modules from being locked and turned on at the same time, so as to achieve a modulation method using step switching, so that the voltage waveform of the target endpoint to the ground end changes in a step wave manner in the second and fourth stages.

[0101] Furthermore, the SPWM modulation method may be, but is not limited to, a two-level SPWM modulation method, a three-level SPWM modulation method, or a multi-level SPWM modulation method.

[0102] For example, assuming that a two-level SPWM modulation method is used, the voltage waveform of the target terminal to the ground terminal is as follows: Figure 6 As shown in the figure, it is a high-frequency voltage waveform, and its fundamental wave is a common frequency sine waveform. Assuming that the three-level SPWM modulation method is adopted, the voltage waveform of the target terminal to the ground terminal is as follows: Figure 7 Assume that the multi-level SPWM modulation method is adopted, the voltage waveform of the target terminal to the ground is as follows Figure 8 shown.

[0103] like Figure 6-Figure 8 As shown, within a switching cycle (ie, modulation cycle), it can be divided into four stages, including: a first time period t1, a second time period t2, a third time period t3 and a fourth time period t4;

[0104] During time t1: the second IGBTs of all submodules in the upper bridge arm are turned on and the first IGBTs are turned off at the same time; the first IGBTs of all submodules in the lower bridge arm are turned on and the second IGBTs are turned off at the same time; the ground potential of the target endpoint is high;

[0105] During time t2: all sub-modules of the upper bridge arm change from the initial state of the second IGBT being on and the first IGBT being blocked, but not changing simultaneously, but adjusting sequentially, gradually changing to the state of the first IGBT being on and the second IGBT being blocked; at the same time, all sub-modules of the lower bridge arm change from the initial state of the first IGBT being on and the second IGBT being blocked, but not changing simultaneously, but adjusting sequentially, gradually changing to the state of the second IGBT being on and the first IGBT being blocked. The ground potential of the target endpoint changes from a high potential to a low potential by stepping down;

[0106] During time t3: the first IGBTs of all submodules in the upper bridge arm are turned on simultaneously, and the second IGBTs are turned off simultaneously. The second IGBTs of all submodules in the lower bridge arm are turned on simultaneously, and the first IGBTs are turned off simultaneously. The ground potential of the target endpoint is at a low point.

[0107] During time t4: all sub-modules of the upper bridge arm change from the initial state of the first IGBT being turned on and the second IGBT being blocked, but not changing at the same time, but adjusting in sequence, gradually changing to the state of the second IGBT being turned on and the first IGBT being blocked; at the same time, all sub-modules of the lower bridge arm change from the initial state of the second IGBT being turned on and the first IGBT being blocked, but not changing at the same time, but adjusting in sequence, gradually changing to the state of the first IGBT being turned on and the second IGBT being blocked, and the ground potential of the target endpoint changes from a low potential to a high potential through a step-up manner.

[0108] The high-voltage, high-power power electronic device provided by the present invention solves the problem of series voltage imbalance by connecting submodules in series, compared with two-level series technology. Compared with modular multi-level technology, the device significantly reduces the capacitance of submodules and the size and weight of the device through an innovative modulation strategy. The voltage stress on the AC side is significantly reduced by adopting a step-switching modulation method.

[0109] This invention proposes a novel high-voltage, high-power power electronic device that combines direct series connection of IGBTs with modular multi-level switching. The AC reactor is placed on the AC side and utilizes two-level, three-level, and multi-level SPWM modulation strategies. This significantly reduces the capacitance of the submodules, significantly reducing the device's size and weight. During the IGBT switching process, a step-wave switching method is used to reduce the AC side voltage dv / dt.

[0110] The present invention provides a high-voltage, high-power power electronic device suitable for flexible DC converter valve application scenarios, but is not limited to high-voltage power electronic applications. It is also suitable for medium and low voltage application scenarios and is suitable for cascading and controlling lower voltage devices.

[0111] Example 2

[0112] The present invention provides a control method for a high-voltage and high-power power electronic device, comprising the following steps:

[0113] A step-switching modulation strategy is adopted to control each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance.

[0114] Furthermore, a step-switching modulation strategy is used to control each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance, including:

[0115] Based on the SPWM modulation method, a step-switching modulation strategy is adopted to control the on / off switching of the first IGBT and the second IGBT in each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance.

[0116] Furthermore, based on the SPWM modulation method, a step-switching modulation strategy is adopted to control the on / off switching of the first IGBT and the second IGBT in each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance, including:

[0117] Divide each preset modulation cycle into four stages, the four stages including: a first time period, a second time period, a third time period and a fourth time period;

[0118] During a first time period, the first IGBTs of each submodule in the upper bridge arm are controlled to be locked simultaneously, the second IGBTs of each submodule in the upper bridge arm are controlled to be turned on simultaneously, the first IGBTs of each submodule in the lower bridge arm are controlled to be turned on simultaneously, and the second IGBTs of each submodule in the lower bridge arm are controlled to be locked simultaneously, so that the ground potential of the target endpoint is a high potential;

[0119] During the second time period, the first IGBTs of each submodule in the upper bridge arm are controlled to be turned on in sequence according to a first preset sequence, the second IGBTs of each submodule in the upper bridge arm are controlled to be blocked in sequence according to a second preset sequence, the first IGBTs of each submodule in the lower bridge arm are controlled to be blocked in sequence according to a third preset sequence, and the second IGBTs of each submodule in the lower bridge arm are controlled to be turned on in sequence according to a fourth preset sequence, so that the ground potential of the target endpoint changes from a high potential to a low potential;

[0120] During a third time period, the first IGBTs of each submodule in the upper bridge arm are controlled to be turned on simultaneously, the second IGBTs of each submodule in the upper bridge arm are controlled to be blocked simultaneously, the first IGBTs of each submodule in the lower bridge arm are controlled to be blocked simultaneously, and the second IGBTs of each submodule in the lower bridge arm are controlled to be turned on simultaneously, so that the ground potential of the target endpoint is low;

[0121] During the fourth time period, the first IGBT of each sub-module in the upper bridge arm is controlled to be locked in sequence according to the fifth preset sequence, the second IGBT of each sub-module in the upper bridge arm is controlled to be turned on in sequence according to the sixth preset sequence, the first IGBT of each sub-module in the lower bridge arm is controlled to be turned on in sequence according to the seventh preset sequence, and the second IGBT of each sub-module in the lower bridge arm is controlled to be locked in sequence according to the eighth preset sequence, so that the ground potential of the target endpoint changes from a low potential to a high potential.

[0122] Furthermore, the SPWM modulation method may be, but is not limited to, a two-level SPWM modulation method, a three-level SPWM modulation method, or a multi-level SPWM modulation method.

[0123] It can be understood that the method embodiment provided above corresponds to the device embodiment above, and the corresponding specific contents can be referenced to each other and will not be repeated here.

[0124] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0125] Example 3

[0126] like Figure 9 As shown, the present invention also provides an electronic device, which may be a computer, a single-chip microcomputer, a smart mobile device, or the like. The electronic device in this embodiment may include a processor, a memory, a transceiver component, and the like. The memory, processor, and transceiver component are connected via a bus; the memory may be used to store an execution program, which may include instructions; and the processor may be used to execute the instructions stored in the memory. The memory may also be used to store data, which may be accessed and / or modified during the execution of the instructions.

[0127] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a control method of a high-voltage and high-power power electronic device in the above embodiment.

[0128] Example 4

[0129] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory), which is a memory device in the electronic device for storing programs and data. It can be understood that the storage medium here can include both the built-in storage medium in the electronic device and, of course, the extended storage medium supported by the electronic device. The storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space. These instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor loads and executes one or more instructions stored in the storage medium, which can implement the steps of a control method of a high-voltage and high-power power electronic device in the above embodiment.

[0130] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0131] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0132] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A high-voltage, high-power power electronic device, characterized in that: include: A controller and a bridge arm unit connected to the AC busbar of the power grid; The bridge arm unit includes: at least one group of bridge arms; each group of bridge arms includes: an AC reactance, an upper bridge arm and a lower bridge arm; the upper bridge arm and the lower bridge arm each include: a plurality of submodules; The upper bridge arm and the lower bridge arm are connected; one end of the AC reactance is connected to the AC busbar of the power grid, and the other end is connected to the connection point between the upper bridge arm and the lower bridge arm; The controller is configured to control each of the submodules using a step-switching modulation strategy, thereby controlling the ground potential of the target endpoint of the AC reactance; The target endpoint is one end of the AC reactance connected to the connection point between the upper bridge arm and the lower bridge arm.

2. The high-voltage and high-power electronic device according to claim 1, characterized in that: The upper bridge arm comprises: a first submodule, a second submodule and a third submodule connected in series in sequence; the lower bridge arm comprises: a fourth submodule, a fifth submodule and a sixth submodule connected in series in sequence; The third submodule is connected to the fourth submodule, and a connection point between the third submodule and the fourth submodule is connected to the other end of the AC reactance.

3. The high-voltage and high-power electronic device according to claim 2, characterized in that: Each submodule includes: an upper tube, a lower tube and a capacitor; the upper tube includes: a first IGBT and a first diode; the lower tube includes: a second IGBT and a second diode; The collector of the first IGBT is connected to the anode of the first diode, and the emitter of the first IGBT is connected to the cathode of the first diode; The collector of the second IGBT is connected to the anode of the second diode, and the emitter of the second IGBT is connected to the cathode of the second diode; The emitter of the first IGBT is connected to the collector of the second IGBT; One end of the capacitor is connected to a connection point between the collector of the first IGBT and the anode of the first diode, and the other end is connected to a second connection point; The connection point between the emitter of the first IGBT and the collector of the second IGBT is the first connection point; the connection point between the emitter of the second IGBT and the cathode of the second diode is the second connection point.

4. The high-voltage and high-power power electronic device according to claim 3, characterized in that: The first connection points of the first submodules are connected to each other and then to the positive pole of the DC bus; The second connection point of the first submodule is connected to the first connection point of the second submodule; The second connection point of the second submodule is connected to the first connection point of the third submodule; The second connection point of the third submodule is connected to the first connection point of the fourth submodule; The second connection point of the fourth submodule is connected to the first connection point of the fifth submodule; The second connection point of the fifth submodule is connected to the first connection point of the sixth submodule; The second connection points of the sixth submodules are connected to each other and then to the negative pole of the DC bus; A connection point between the second connection point of the third submodule and the first connection point of the fourth submodule is connected to the other end of the AC reactance.

5. The high-voltage and high-power electronic device according to claim 1, characterized in that: The bridge arm unit is a half bridge; the half bridge includes: a group of bridge arms.

6. The high-voltage and high-power electronic device according to claim 1, characterized in that: The bridge arm unit is an H bridge; the H bridge includes: two groups of bridge arms.

7. The high-voltage and high-power electronic device according to claim 1, characterized in that: The bridge arm unit is a three-phase bridge; the three-phase bridge includes: three groups of bridge arms.

8. The high-voltage, high-power electronic device according to claim 3, characterized in that: The controller includes: A control unit is used to control the on / off of the first IGBT and the second IGBT in each of the submodules based on an SPWM modulation method and a step-switching modulation strategy, thereby controlling the ground potential of the target endpoint of the AC reactance.

9. The high-voltage, high-power electronic device according to claim 8, characterized in that: The control unit comprises: A division module, configured to divide each preset modulation cycle into four phases, wherein the four phases include: a first time period, a second time period, a third time period, and a fourth time period; a first control module, configured to control, within a first time period, the first IGBTs of the submodules in the upper bridge arm to be simultaneously locked, control the second IGBTs of the submodules in the upper bridge arm to be simultaneously turned on, control the first IGBTs of the submodules in the lower bridge arm to be simultaneously turned on, and control the second IGBTs of the submodules in the lower bridge arm to be simultaneously locked, so that the ground potential of the target endpoint is a high potential; a second control module, configured to control, within a second time period, the first IGBTs of the submodules in the upper bridge arm to be turned on sequentially according to a first preset sequence, control the second IGBTs of the submodules in the upper bridge arm to be blocked sequentially according to a second preset sequence, control the first IGBTs of the submodules in the lower bridge arm to be blocked sequentially according to a third preset sequence, and control the second IGBTs of the submodules in the lower bridge arm to be turned on sequentially according to a fourth preset sequence, so that the ground potential of the target endpoint changes from a high potential to a low potential; a third control module, configured to control, within a third time period, the first IGBTs of the submodules in the upper bridge arm to be turned on simultaneously, control the second IGBTs of the submodules in the upper bridge arm to be blocked simultaneously, control the first IGBTs of the submodules in the lower bridge arm to be blocked simultaneously, and control the second IGBTs of the submodules in the lower bridge arm to be turned on simultaneously, so that the ground potential of the target endpoint is low; The fourth control module is used to control the first IGBT of each sub-module in the upper bridge arm to be locked in sequence according to the fifth preset order, control the second IGBT of each sub-module in the upper bridge arm to be turned on in sequence according to the sixth preset order, control the first IGBT of each sub-module in the lower bridge arm to be turned on in sequence according to the seventh preset order, and control the second IGBT of each sub-module in the lower bridge arm to be locked in sequence according to the eighth preset order, so that the ground potential of the target endpoint changes from a low potential to a high potential.

10. The high-voltage and high-power power electronic device according to claim 8, characterized in that: The SPWM modulation method is: a two-level SPWM modulation method, a three-level SPWM modulation method, or a multi-level SPWM modulation method.

11. A control method for a high-voltage, high-power electronic device, applied to the high-voltage, high-power electronic device according to any one of claims 1 to 9, characterized in that: include: A step-switching modulation strategy is adopted to control each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance.

12. The method according to claim 11, characterized in that The step-by-step switching modulation strategy is used to control each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance, including: Based on the SPWM modulation method, a step-switching modulation strategy is adopted to control the on / off switching of the first IGBT and the second IGBT in each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance.

13. The method according to claim 11, characterized in that The SPWM modulation method adopts a step-switching modulation strategy to control the on / off of the first IGBT and the second IGBT in each submodule, thereby controlling the ground potential of the target endpoint of the AC reactance, including: Dividing each preset modulation cycle into four stages, the four stages comprising: a first time period, a second time period, a third time period and a fourth time period; During a first time period, the first IGBTs of each submodule in the upper bridge arm are controlled to be simultaneously locked, the second IGBTs of each submodule in the upper bridge arm are controlled to be simultaneously turned on, the first IGBTs of each submodule in the lower bridge arm are controlled to be simultaneously turned on, and the second IGBTs of each submodule in the lower bridge arm are controlled to be simultaneously locked, so that the ground potential of the target endpoint is a high potential; During a second time period, the first IGBTs of the submodules in the upper bridge arm are controlled to be turned on in sequence according to a first preset sequence, the second IGBTs of the submodules in the upper bridge arm are controlled to be blocked in sequence according to a second preset sequence, the first IGBTs of the submodules in the lower bridge arm are controlled to be blocked in sequence according to a third preset sequence, and the second IGBTs of the submodules in the lower bridge arm are controlled to be turned on in sequence according to a fourth preset sequence, so that the ground potential of the target endpoint changes from a high potential to a low potential; In a third time period, the first IGBTs of each submodule in the upper bridge arm are controlled to be turned on simultaneously, the second IGBTs of each submodule in the upper bridge arm are controlled to be blocked simultaneously, the first IGBTs of each submodule in the lower bridge arm are controlled to be blocked simultaneously, and the second IGBTs of each submodule in the lower bridge arm are controlled to be turned on simultaneously, so that the ground potential of the target endpoint is low; During the fourth time period, the first IGBT of each sub-module in the upper bridge arm is controlled to be locked in sequence according to the fifth preset order, the second IGBT of each sub-module in the upper bridge arm is controlled to be turned on in sequence according to the sixth preset order, the first IGBT of each sub-module in the lower bridge arm is controlled to be turned on in sequence according to the seventh preset order, and the second IGBT of each sub-module in the lower bridge arm is controlled to be locked in sequence according to the eighth preset order, so that the ground potential of the target endpoint changes from a low potential to a high potential.

14. The method according to claim 12, characterized in that The SPWM modulation method is: a two-level SPWM modulation method, a three-level SPWM modulation method, or a multi-level SPWM modulation method.

15. An electronic device, characterized in that: include: at least one processor and memory; The memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the control method of the high-voltage and high-power power electronic device according to any one of claims 11 to 14 is implemented.

16. A readable storage medium, characterized in that An execution program is stored thereon, and when the execution program is executed, the control method of the high-voltage and high-power power electronic device according to any one of claims 11 to 14 is implemented.

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