Current distortion suppression method, controller, rectification system, and storage medium

Abstract

The application provides a current distortion suppression method, a controller, a rectifying system and a storage medium. The method is applied to a Vienna rectifier, and the method comprises the following steps: monitoring a modulation voltage waveform of a target phase of the Vienna rectifier; wherein the target phase is any one phase in three phases of the Vienna rectifier, and the modulation voltage waveform is used for controlling an input current of the target phase; and performing voltage compensation on the modulation voltage waveform of the target phase in a zero-crossing interval, so that the input current corresponding to the compensated zero-crossing interval is reduced compared with that before compensation; wherein the zero-crossing interval is centered on a zero-crossing point of a standard modulation voltage waveform of the target phase. The application can suppress current zero-crossing point distortion of the Vienna rectifier.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of distortion control, and in particular to a current distortion suppression method, a controller, a rectification system and a storage medium. BACKGROUND

[0002] The Vienna rectifier is a widely used power converter, which should meet important limit conditions in normal operation. When the rectifier operates in a non-ideal condition, using the traditional carrier modulation strategy will violate the important limit condition, and the current waveform will be distorted at the zero-crossing point, affecting the performance of the Vienna rectifier. SUMMARY

[0003] The embodiments of the present application provide a current distortion suppression method, a controller, a rectification system and a storage medium to solve the problem of distortion of the current waveform of the Vienna rectifier at the zero-crossing point.

[0004] In a first aspect, the embodiments of the present application provide a current distortion suppression method applied to a Vienna rectifier, which comprises:

[0005] Monitoring the modulation voltage waveform of the target phase of the Vienna rectifier; wherein the target phase is any one of the three phases of the Vienna rectifier, and the modulation voltage waveform is used to control the input current of the target phase;

[0006] Performing voltage compensation on the modulation voltage waveform of the target phase in the zero-crossing interval to reduce the input current corresponding to the compensated zero-crossing interval compared with the input current before compensation; wherein the zero-crossing interval is centered on the zero-crossing point of the standard modulation voltage waveform of the target phase.

[0007] In a possible implementation, the modulation voltage waveform of the target phase includes a positive modulation waveform greater than zero and a negative modulation waveform less than zero;

[0008] The voltage compensation on the modulation voltage waveform of the target phase in the zero-crossing interval comprises:

[0009] Increasing the voltage of the positive modulation waveform in the zero-crossing interval by a first preset voltage value;

[0010] Subtracting the voltage of the negative modulation waveform in the zero-crossing interval by a second preset voltage value;

[0011] Wherein, the first preset voltage value and the second preset voltage value are positive values, and the input current of the target phase decreases with the increase of the first preset voltage value in the zero-crossing interval, and the input current of the target phase decreases with the increase of the second preset voltage value in the zero-crossing interval.

[0012] In a possible implementation, the first preset voltage value and the second preset voltage value are equal.

[0013] In a possible implementation, the target phase includes a first phase, a second phase and a third phase of the Vienna rectifier.

[0014] The voltage of the positive modulation waveform in the zero-crossing interval is increased by the first preset voltage value, including:

[0015] The voltage of the positive modulation waveform in the zero-crossing interval is increased by the first preset voltage value, including:

[0016] The voltage of the negative modulation waveform in the zero-crossing interval is decreased by the second preset voltage value, including:

[0017] The voltage of the positive modulation waveform in the zero-crossing interval is increased by the first preset voltage value, including:

[0018] After the voltage compensation of the modulation voltage waveform of the target phase in the zero-crossing interval, the switch corresponding to the target phase is controlled according to the compensated modulation voltage waveform of the target phase.

[0019] In a possible implementation, the method further includes:

[0020] Monitoring the current output power of the Vienna rectifier.

[0021] According to the current output power, the interval length of the zero-crossing interval is determined.

[0022] According to the interval length and the zero-crossing point of the standard voltage waveform of the target phase, the zero-crossing interval is determined.

[0023] In a possible implementation, according to the current output power, the interval length of the zero-crossing interval is determined, including:

[0024] According to the collection delay and the control delay, the interval length of the zero-crossing interval is determined under the current output power; the collection delay is the delay of collecting the parameters of the Vienna rectifier, and the control delay is the delay of controlling the action of the Vienna rectifier.

[0025] In a possible implementation, according to the current output power, the interval length of the zero-crossing interval is determined, including:

[0026] When the current output power is less than or equal to a first preset power value, the interval length is determined as a first length;

[0027] When the current output power is greater than the first preset power value and less than or equal to a second preset power value, the interval length is determined as a second length;

[0028] When the current output power is greater than the second preset power value, the interval length is determined as a third length.

[0029] The first preset power value is less than or equal to the second preset power value; the second length is a decreasing function of the current output power, and the upper limit of the value range of the second length is the first length, and the lower limit is the third length.

[0030] In a second aspect, an embodiment of the present application provides a current distortion suppression device applied to a Vienna rectifier, and the device comprises:

[0031] A first monitoring module is configured to monitor a modulation voltage waveform of a target phase of the Vienna rectifier; the target phase is any one of three phases of the Vienna rectifier.

[0032] A control module is configured to perform voltage compensation on the modulation voltage waveform of the target phase in a zero-crossing interval, so that an error between a voltage at a zero-crossing point in the zero-crossing interval and zero is less than a preset threshold; the zero-crossing interval is centered on the zero-crossing point of a standard modulation voltage waveform of the target phase.

[0033] In a third aspect, an embodiment of the present application provides a controller comprising a memory and a processor, the memory stores a computer program capable of running on the processor, and the processor implements the steps of the current distortion suppression method of the first aspect or any possible implementation manner of the first aspect when executing the computer program.

[0034] In a fourth aspect, an embodiment of the present application provides a rectification system comprising the controller of the third aspect and a Vienna rectifier; the Vienna rectifier is controlled by the controller.

[0035] In a fifth aspect, an embodiment of the present application provides a computer readable storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the current distortion suppression method of the first aspect or any possible implementation manner of the first aspect.

[0036] The embodiment of the present application provides a current distortion suppression method, a controller, a rectifying system and a storage medium, the target phase modulation voltage waveform of a Vienna rectifier is monitored, the target phase modulation voltage waveform in the zero-crossing interval is subjected to voltage compensation, so that the current distortion of the target phase at the zero-crossing point is suppressed, the control mode is simple, and the working reliability of the Vienna rectifier can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0038] Figure 1 is a Vienna rectifier current waveform diagram provided by the embodiment of the present application;

[0039] Figure 2 is a circuit structure schematic diagram of a Vienna rectifier provided by the embodiment of the present application;

[0040] Figure 3 is a phase relationship diagram of a non-ideal Vienna rectifier provided by the embodiment of the present application;

[0041] Figure 4 is an implementation flowchart of the current distortion suppression method provided by the embodiment of the present application;

[0042] Figure 5 is a three-phase voltage waveform diagram of a Vienna rectifier provided by the embodiment of the present application;

[0043] Figure 6 is a modulation voltage waveform diagram of a Vienna rectifier before compensation provided by the embodiment of the present application;

[0044] Figure 7 is a modulation voltage waveform diagram of a Vienna rectifier after compensation provided by the embodiment of the present application;

[0045] Figure 8 is a Vienna rectifier current waveform diagram after compensation provided by the embodiment of the present application;

[0046] Figure 9 is a structure schematic diagram of a current distortion suppression device provided by the embodiment of the present application;

[0047] Figure 10 is a schematic diagram of a controller provided by the embodiment of the present application. DETAILED DESCRIPTION

[0048] In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, circuits, and

[0049] In order to make the objects, technical solutions and advantages of the present application clearer, the following will be described by specific embodiments in conjunction with the accompanying drawings.

[0050] Referring to Figure 1 , it shows the Vienna rectifier current waveform diagram provided by the embodiments of the present application. As shown in the figure, the inventors find that after replacing the boost inductance and MOS tube on the PFC side of the 15K reduction power module, the input current harmonics will increase, exceeding the index requirement. Under half load, the harmonic size is 4.6%, 4.5%, 5.05%, obviously exceeding the index requirement. According to Figure 1 It can be obtained that the current distortion is more obvious, especially at the input voltage zero crossing point.

[0051] The Vienna rectifier needs to meet the important restriction condition (IR) for normal operation: the polarity of the input port voltage of each phase of the Vienna rectifier must be consistent with the polarity of the corresponding grid-side current of each phase. This is determined by the circuit structure of the Vienna rectifier itself, as shown in Figure 2 As can be seen from the analysis of the circuit topology diagram, the value of the input port voltage is determined by the polarity of the input current and the switching state, and the polarity of the input port voltage is consistent with the polarity of the input current.

[0052] The Vienna rectifier should meet the important restriction condition when it is in normal operation. However, when the rectifier is in a non-ideal situation, the use of the traditional carrier modulation strategy will violate the important restriction condition. As shown in Figure 3 , it shows the phase relationship diagram of the non-ideal Vienna rectifier provided by the embodiments of the present application. For the three-phase Vienna rectifier, the influence of the offset voltage in the modulation wave on the line voltage is offset, so only the sinusoidal reference voltage is considered. Figure 3 In the prior art, the phase angle of the input current (ik) can be made to track the phase angle of the grid voltage (vk) through dq control, but the sinusoidal modulation voltage waveform will lag the input current waveform, and the phase angle difference is θz. Therefore, the important restriction condition is not met at the current zero crossing point, and the current waveform will be distorted at the zero crossing point, and when the internal resistance of the inductance increases or the amplitude of the input current increases, the phase angle difference θz also increases.

[0053] To solve the current zero-crossing distortion problem of the Vienna rectifier, an embodiment of the present application provides a current distortion suppression method, as shown in Figure 4 , which shows an implementation flowchart of the current distortion suppression method provided by the embodiment of the present application. As shown in Figure 4 , a current distortion suppression method applied to a Vienna rectifier can include the following steps:

[0054] S101, monitoring a modulation voltage waveform of a target phase of the Vienna rectifier; wherein the target phase is any one of the three phases of the Vienna rectifier, and the modulation voltage waveform is used to control the input current of the target phase.

[0055] Optionally, the three phases of the Vienna rectifier include a first phase, a second phase, and a third phase. Each phase corresponds to a group of switching tubes. The modulation voltage waveform is a sine wave with time or period on the horizontal axis and voltage on the vertical axis. The modulation voltage waveform of the target phase is used to control the switching tube of the target phase, thereby controlling the current waveform of the target phase. The modulation voltage waveform of each phase can be obtained through the PFC control loop of the Vienna rectifier.

[0056] For example, as shown in Figure 2 , the modulation voltage waveform of the first phase a is used to control the switching tubes Sa1 and Sa2, the modulation voltage waveform of the second phase b is used to control the switching tubes Sb1 and Sb2, and the modulation voltage waveform of the third phase c is used to control the switching tubes Sc1 and Sc2.

[0057] S102, voltage compensation is performed on the modulation voltage waveform of the target phase within the zero-crossing interval, so that the input current corresponding to the compensated zero-crossing interval is reduced compared with that before compensation; wherein the zero-crossing interval is centered on the zero-crossing point of the standard modulation voltage waveform of the target phase.

[0058] Optionally, the modulation voltage waveform of the target phase not within the zero-crossing interval is not compensated, and the switching tube corresponding to the target phase is controlled according to the compensated modulation voltage waveform of the target phase, so that the current waveform of the target phase finally meets the relevant parameter requirements of the zero-crossing point.

[0059] Optionally, the standard modulation voltage waveform is a standard sine wave. For the standard sine wave, it can include three zero-crossing points of 0, π, and 2π in a period. At the zero-crossing point, the voltage value of the standard modulation voltage waveform is zero. The zero-crossing interval is the neighborhood centered on the zero-crossing point, that is, the region including a part of the width on both sides of the zero-crossing point.

[0060] Generally, the modulation voltage waveform of the target phase will lag behind the voltage waveform of the target phase due to the boost inductance. The zero-crossing interval can also be the right neighborhood of the zero-crossing point. However, considering that the hardware circuit acquisition and judgment process requires a certain time, therefore, the zero-crossing interval is generally the neighborhood centered on the zero-crossing point. The range and interval length of the zero-crossing interval can be set according to actual needs.

[0061] The phases of the Vienna rectifier are 120° apart, and the zero-crossing points of the phases are all different in one grid cycle, therefore, the interval length of the zero-crossing interval of each phase of the Vienna rectifier is the same, but the position of the zero-crossing interval is different, and each phase corresponds to a different zero-crossing interval.

[0062] For example, referring to Figure 5 , a three-phase voltage waveform diagram of the Vienna rectifier provided by the embodiment of the present application is shown. As Figure 5 shown, in one grid cycle, the zero-crossing points of Ua, Ub and Uc are all different, and the present application will compensate each phase respectively to achieve the purpose of suppressing the zero-crossing distortion.

[0063] Optionally, the input current without compensation will have current distortion at the zero-crossing point, and the distortion rate is high. By compensating the modulation voltage waveform of the target phase, the current value of the input current in the zero-crossing interval can be reduced, and the distortion rate of the input current is reduced, thereby achieving the purpose of suppressing the current distortion in the zero-crossing interval.

[0064] The embodiment of the present application compensates the modulation voltage waveform of the target phase in the zero-crossing interval of the target phase, so that the current distortion rate of the target phase at the zero-crossing point is reduced, thereby achieving the purpose of suppressing the current distortion of the target phase at the zero-crossing point. The control method is simple, has high compatibility, has wide application range, can improve the working reliability of the Vienna rectifier, and ensures the power safety of the equipment.

[0065] In some embodiments of the present application, the modulation voltage waveform of the target phase includes a positive modulation waveform greater than zero and a negative modulation waveform less than zero; the voltage compensation of the modulation voltage waveform of the target phase in the zero-crossing interval in the above S102 can include:

[0066] The voltage of the positive modulation waveform in the zero-crossing interval is increased by a first preset voltage value;

[0067] The voltage of the negative modulation waveform in the zero-crossing interval is reduced by a second preset voltage value;

[0068] Wherein, the first preset voltage value and the second preset voltage value are positive values, the input current of the target phase decreases with the increase of the first preset voltage value in the zero-crossing interval, and the input current of the target phase decreases with the increase of the second preset voltage value in the zero-crossing interval.

[0069] Optionally, the first preset voltage value and the second preset voltage value are obtained according to experiments and are positive values. When the modulation voltage waveform of the target phase is not compensated, the current value of the forward current of the target phase at the zero-crossing point is generally greater than zero, and the current value of the negative current of the target phase at the zero-crossing point is generally less than zero.

[0070] Specifically, the first preset voltage value and the second preset voltage value can be the same or different, and can be determined according to the compensation accuracy and the compensation complexity. When the first preset voltage value and the second preset voltage value are the same, the compensation complexity of the target phase can be reduced. When the first preset voltage value and the second preset voltage value are different, the compensation accuracy of the target phase can be improved. By selecting appropriate first preset voltage values and second preset voltage values through compensation accuracy and compensation complexity, the compatibility is higher and the selection range is wider.

[0071] By increasing the first preset voltage value to the voltage of the positive modulation waveform of the target phase in the zero-crossing interval, the duty cycle of the corresponding switch tube of the target phase can be reduced, and then the current value of the target phase at the zero-crossing point tends to zero. By subtracting the second preset voltage value from the voltage of the negative modulation waveform of the target phase in the zero-crossing interval, the duty cycle of the corresponding switch tube of the target phase can also be reduced, and then the current value of the target phase at the zero-crossing point tends to zero. Through positive compensation and negative compensation, the positive distortion and negative distortion of the current can be reduced respectively. For Vienna rectifiers with different distortion rate requirements, targeted compensation can be performed, the working reliability can be considered, and the design cost can be reduced according to the actual performance of the device.

[0072] Exemplarily, referring to Figure 6 which shows the modulation voltage waveform diagram of the Vienna rectifier before compensation provided by the embodiment of the present application. Referring to Figure 7 which shows the modulation voltage waveform diagram of the Vienna rectifier after compensation provided by the embodiment of the present application. By comparing Figure 6 and Figure 7 , the voltage of the modulation voltage waveform of the target phase after compensation at the zero-crossing point is greatly different from that of the zero phase, and the voltage of the modulation voltage waveform of the target phase before compensation at the zero-crossing point tends to zero, which effectively suppresses the current distortion of the target phase.

[0073] Optionally, the target phase includes a first phase, a second phase and a third phase of the Vienna rectifier.

[0074] The voltage of the positive modulation waveform in the zero-crossing interval is increased by a first preset voltage value, which can specifically include:

[0075] The voltage of the positive modulation waveform of the first phase in the zero-crossing interval is increased by a first preset voltage value; the voltage of the positive modulation waveform of the second phase in the zero-crossing interval is increased by a first preset voltage value; and the voltage of the positive modulation waveform of the third phase in the zero-crossing interval is increased by a first preset voltage value.

[0076] The voltage of the negative modulation waveform in the zero-crossing interval is decreased by a second preset voltage value, which can specifically include:

[0077] The voltage of the positive modulation waveform of the first phase in the zero-crossing interval is decreased by a second preset voltage value; the voltage of the positive modulation waveform of the second phase in the zero-crossing interval is decreased by a second preset voltage value; and the voltage of the positive modulation waveform of the third phase in the zero-crossing interval is decreased by a second preset voltage value.

[0078] After the voltage compensation of the modulation voltage waveform of the target phase in the zero-crossing interval, the switch corresponding to the target phase is controlled according to the compensated modulation voltage waveform of the target phase

[0079] The first preset voltage value and the second preset voltage value can be used to compensate the modulation voltage waveforms of the first phase, the second phase and the third phase, respectively. Appropriate compensation voltage values can also be selected for each phase.

[0080] For example, for a Vienna rectifier with low compensation accuracy requirement, the same compensation voltage value can be used to compensate the modulation voltage waveforms of each phase. For a Vienna rectifier with high compensation accuracy requirement, appropriate compensation voltage values can be selected for each phase, or even for the positive modulation waveform and the negative modulation waveform of each phase, to reduce the current distortion rate of each phase at the zero-crossing point as much as possible. See Figure 8 which shows the compensated Vienna rectifier current waveform diagram provided by the embodiment of the present application, as shown in Figure 8 compared with Figure 1 , the harmonic size is optimized to 2.52%, 2.59%, and 3.13%, which is reduced by about 2%, and meets the relevant index requirements.

[0081] In the present application, one phase, two phases or three phases of the Vienna rectifier can be compensated in the zero-crossing interval, which is specifically selected according to actual needs.

[0082] In some embodiments of the present application, the interval length of the zero-crossing interval can be determined according to the power of the Vienna rectifier, which specifically includes:

[0083] monitoring a current output power of the Vienna rectifier;

[0084] determining an interval length of the zero-crossing interval according to the current output power;

[0085] determining the zero-crossing interval according to the interval length and a zero-crossing point of the standard voltage waveform of the target phase.

[0086] For the Vienna rectifier, the greater the output power, the less the current distortion affects it, and the smaller the interval length of the zero-crossing interval can be. The pulse blocking time of the switching tube can be reduced while suppressing current distortion, and the working efficiency of the Vienna rectifier can be improved.

[0087] Optionally, the relationship between the current output power and the interval length can be set by the actually measured optimal harmonic result.

[0088] Optionally, the "determining an interval length of the zero-crossing interval according to the current output power" of the embodiment includes the following two ways:

[0089] The first way is to determine the interval length of the zero-crossing interval according to the collection delay and the control delay under the current output power. The collection delay is the delay of collecting the parameters of the Vienna rectifier, and the control delay is the delay of controlling the action of the Vienna rectifier.

[0090] Generally, it takes a certain time to collect the related parameters of the Vienna rectifier, and it also takes a certain time to control the related actions of the Vienna rectifier. The relationship between the collection delay, the control delay and the interval length of the zero-crossing interval under different powers can be set by pre-experiment in the form of a data table. The interval length of the zero-crossing interval of the Vienna rectifier under different powers is determined by looking up the table to ensure the compensation effect of the modulation voltage waveform of the target phase, to suppress the distortion rate of the input current of the target phase at the zero-crossing point, and to improve the working performance of the overall Vienna rectifier.

[0091] The second way is to determine the interval length as a first length when the current output power is less than or equal to a first preset power value.

[0092] The interval length is determined as a second length when the current output power is greater than the first preset power value and less than or equal to a second preset power value.

[0093] The interval length is determined as a third length when the current output power is greater than the second preset power value.

[0094] The first preset power value is less than or equal to the second preset power value. The second length is a decreasing function of the current output power, and the upper limit of the value range of the second length is the first length, and the lower limit is the third length.

[0095] wherein the formula for selecting the length of the interval according to the current output power is:

[0096]

[0097] wherein D is the length of the interval, and P is the current output power. Namely:

[0098] when the current output power P of the Vienna rectifier is less than or equal to 10kw, the length of the interval D is 0.1;

[0099] when the current output power P of the Vienna rectifier is between 10kw and 20kw, the length of the interval D is linearly reduced from 0.1 to 0;

[0100] when the current output power P of the Vienna rectifier is greater than or equal to 20kw, the length of the interval D is 0.

[0101] For example, for a target phase, assuming that the zero-crossing point of the phase is 0 and π, when the current output power is 10kw, the zero-crossing interval of the target phase includes [-0.05, 0.05] and [π-0.05, π+0.05], and the voltage compensation is performed on the modulation voltage waveform of the target phase in the two intervals.

[0102] The present application can inhibit the current zero-crossing distortion of the Vienna rectifier, effectively reduce the ripple, and improve the working efficiency of the Vienna rectifier by performing compensation on the modulation voltage waveform of the target phase in the zero-crossing interval, demodulating the compensated modulation voltage waveform to obtain a corresponding compensated PWM (Pulse Width Modulation) wave, and controlling the corresponding switching tube according to the PWM wave.

[0103] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0104] The following is a device embodiment of the present application, and for details not described in detail, reference can be made to the corresponding method embodiments described above.

[0105] Figure 9 The structure of the current distortion suppression device provided by the embodiment of the present application is shown, only the part related to the embodiment of the present application is shown for convenience of description, and the details are as follows:

[0106] As Figure 9As shown, the current distortion suppression device 20 is applied to a Vienna rectifier, the device 20 can include:

[0107] The first monitoring module 201 is configured to monitor a modulation voltage waveform of a target phase of the Vienna rectifier; wherein the target phase is any one of the three phases of the Vienna rectifier, and the modulation voltage waveform is used to control the input current of the target phase.

[0108] The control module 202 is configured to perform voltage compensation on the modulation voltage waveform of the target phase in the zero-crossing interval, so that the input current corresponding to the compensated zero-crossing interval is smaller than that before compensation; wherein the zero-crossing interval is centered on the zero-crossing point of the standard modulation voltage waveform of the target phase.

[0109] In some embodiments of the present application, the modulation voltage waveform of the target phase includes a positive modulation waveform greater than zero and a negative modulation waveform less than zero; the control module 202 can include:

[0110] The first compensation unit is configured to increase the voltage of the positive modulation waveform in the zero-crossing interval by a first preset voltage value;

[0111] The second compensation unit is configured to subtract a second preset voltage value from the voltage of the negative modulation waveform in the zero-crossing interval; wherein the first preset voltage value and the second preset voltage value are both positive values, the input current of the target phase decreases with the increase of the first preset voltage value in the zero-crossing interval, and the input current of the target phase decreases with the increase of the second preset voltage value in the zero-crossing interval.

[0112] In some embodiments of the present application, the first preset voltage value and the second preset voltage value are equal.

[0113] In some embodiments of the present application, the target phase includes a first phase, a second phase and a third phase of the Vienna rectifier;

[0114] The first compensation unit is specifically configured to increase the voltage of the positive modulation waveform of the first phase in the zero-crossing interval by a first preset voltage value; increase the voltage of the positive modulation waveform of the second phase in the zero-crossing interval by a first preset voltage value; and increase the voltage of the positive modulation waveform of the third phase in the zero-crossing interval by a first preset voltage value;

[0115] The second compensation unit is specifically configured to subtract a second preset voltage value from the voltage of the positive modulation waveform of the first phase in the zero-crossing interval; subtract a second preset voltage value from the voltage of the positive modulation waveform of the second phase in the zero-crossing interval; and subtract a second preset voltage value from the voltage of the positive modulation waveform of the third phase in the zero-crossing interval;

[0116] The control unit is configured to control the switch corresponding to the target phase according to the modulated voltage waveform of the target phase after voltage compensation is performed on the modulated voltage waveform of the target phase in the zero-crossing interval.

[0117] In some embodiments of the present application, the device 20 can further include:

[0118] The second monitoring module is configured to monitor the current output power of the Vienna rectifier.

[0119] The selection module is configured to determine the interval length of the zero-crossing interval according to the current output power.

[0120] The interval determination module is configured to determine the zero-crossing interval according to the interval length and the zero-crossing point of the standard voltage waveform of the target phase.

[0121] The selection module can include:

[0122] The first selection unit is configured to determine the interval length of the zero-crossing interval according to the collection delay and the control delay when the current output power is less than or equal to the first preset power value, the collection delay being a delay for collecting parameters of the Vienna rectifier, and the control delay being a delay for controlling actions of the Vienna rectifier.

[0123] The selection module can include:

[0124] The second selection unit is configured to determine the interval length as the first length when the current output power is less than or equal to the first preset power value.

[0125] The third selection unit is configured to determine the interval length as the second length when the current output power is greater than the first preset power value and less than or equal to the second preset power value.

[0126] The fourth selection unit is configured to determine the interval length as the third length when the current output power is greater than the second preset power value, the first preset power value being less than or equal to the second preset power value, the second length being a decreasing function of the current output power, and the upper limit of the value range of the second length being the first length and the lower limit being the third length.

[0127] Figure 10 is a schematic diagram of a controller provided by an embodiment of the present application. As shown in Figure 10 the controller 30 of this embodiment includes a processor 300 and a memory 301, and the memory 301 stores a computer program 302 that can run on the processor 300. The processor 300 implements the steps in each of the current distortion suppression method embodiments when executing the computer program 302, such as Figure 4 S101-S102 shown in the drawings. Alternatively, the processor 300 implements the functions of each module / unit in each of the device embodiments when executing the computer program 302, such asFigure 9 the functions of the illustrated modules / units 201-202.

[0128] For example, the computer program 302 can be segmented into one or more modules / units, which are stored in the memory 301 and executed by the processor 300 to complete the present application. One or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 302 in the controller 30. For example, the computer program 302 can be segmented into Figure 9 the illustrated modules / units 201-202.

[0129] The controller 30 can be a DSP or a single-chip microcomputer module. The controller 30 can include, but is not limited to, the processor 300, the memory 301. Those skilled in the art can understand that the controller 30 can include more or fewer components than those shown, or combine certain components, or include different components, for example, the controller can also include an input / output device, a network access device, a bus, etc. Figure 10 The controller 30 shown is only an example and does not constitute a limitation on the controller 30, and can include more or fewer components than those shown, or combine certain components, or different components, for example, the controller can also include an input / output device, a network access device, a bus, etc.

[0130] The processor 300 can be a central processing unit (CPU), and can also be 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. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0131] The memory 301 can be an internal storage unit of the controller 30, such as a hard disk or a memory of the controller 30. The memory 301 can also be an external storage device of the controller 30, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 301 can include both an internal storage unit and an external storage device of the controller 30. The memory 301 is used to store computer programs and other programs and data required by the controller. The memory 301 can also be used to temporarily store data that has been output or will be output.

[0132] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or software. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the present application. The specific working process of the unit and module in the above system can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

[0133] The embodiment of the present application also provides a rectifier system, comprising the controller 30 and the Vienna rectifier as above; the Vienna rectifier is controlled by the controller 30.

[0134] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the related description of other embodiments.

[0135] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0136] In the embodiments provided by the present application, it should be understood that the disclosed device / controller and method can be implemented in other ways. For example, the device / controller embodiments described above are only schematic, for example, the division of the modules or units is only a logical function division, and there can be another division manner in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0137] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0138] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0139] If the integrated module / unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. When the processor executes the computer program, the steps of each current distortion suppression method embodiment can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable file or some intermediate form. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0140] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A current distortion suppression method characterized by comprising: The method is applied to a Vienna rectifier, and the method comprises the following steps: monitoring a modulation voltage waveform of a target phase of the Vienna rectifier; wherein the target phase is any one of three phases of the Vienna rectifier, and the modulation voltage waveform is used for controlling an input current of the target phase; performing voltage compensation on the modulation voltage waveform of the target phase in a zero-crossing interval, so that the input current corresponding to the compensated zero-crossing interval is smaller than that before compensation; wherein the zero-crossing interval is centered on a zero-crossing point of a standard modulation voltage waveform of the target phase; the modulation voltage waveform of the target phase comprises a positive modulation waveform greater than zero and a negative modulation waveform less than zero; the voltage compensation on the modulation voltage waveform of the target phase in the zero-crossing interval comprises: increasing the voltage of the positive modulation waveform in the zero-crossing interval by a first preset voltage value; subtracting the voltage of the negative modulation waveform in the zero-crossing interval by a second preset voltage value; wherein the first preset voltage value and the second preset voltage value are positive values, the input current of the target phase decreases with the increase of the first preset voltage value in the zero-crossing interval, and the input current of the target phase decreases with the increase of the second preset voltage value in the zero-crossing interval.

2. The current distortion suppression method according to claim 1, characterized by, the first preset voltage value is equal to the second preset voltage value.

3. The current distortion suppression method according to claim 1, characterized by, the target phase comprises a first phase, a second phase and a third phase of the Vienna rectifier; the voltage increase of the positive modulation waveform in the zero-crossing interval by the first preset voltage value comprises: increasing the voltage of the positive modulation waveform of the first phase in the zero-crossing interval by the first preset voltage value; increasing the voltage of the positive modulation waveform of the second phase in the zero-crossing interval by the first preset voltage value; and increasing the voltage of the positive modulation waveform of the third phase in the zero-crossing interval by the first preset voltage value; the voltage subtraction of the negative modulation waveform in the zero-crossing interval by the second preset voltage value comprises: subtracting the voltage of the negative modulation waveform of the first phase in the zero-crossing interval by the second preset voltage value; subtracting the voltage of the negative modulation waveform of the second phase in the zero-crossing interval by the second preset voltage value; and subtracting the voltage of the negative modulation waveform of the third phase in the zero-crossing interval by the second preset voltage value; after the voltage compensation on the modulation voltage waveform of the target phase in the zero-crossing interval, controlling a switch tube corresponding to the target phase according to the compensated modulation voltage waveform of the target phase.

4. The current distortion suppression method according to any one of claims 1 to 3, characterized by, the method further comprises: monitoring a current output power of the Vienna rectifier; determining an interval length of the zero-crossing interval according to the current output power; determining the zero-crossing interval according to the interval length and a zero-crossing point of a standard voltage waveform of the target phase.

5. The current distortion suppression method according to claim 4, characterized by, the determination of the interval length of the zero-crossing interval according to the current output power comprises: Determine the interval length of the zero-crossing interval according to the current output power, a collection delay and a control delay; the collection delay is a delay for collecting the Vienna rectifier parameters, and the control delay is a delay for controlling the Vienna rectifier.

6. The current distortion suppression method according to claim 4, characterized by, The step of determining the interval length of the zero-crossing interval according to the current output power comprises: When the current output power is less than or equal to a first preset power value, determine the interval length as a first length; When the current output power is greater than the first preset power value and less than or equal to a second preset power value, determine the interval length as a second length; When the current output power is greater than the second preset power value, determine the interval length as a third length; The first preset power value is less than the second preset power value; the second length is a decreasing function of the current output power, and the upper limit of the value range of the second length is the first length, and the lower limit is the third length.

7. A controller comprising a memory and a processor, the memory having stored therein a computer program executable on the processor, characterized in that, The processor executes the computer program to implement the steps of the current distortion suppression method according to any one of claims 1 to 6.

8. A rectifying system characterized by, The controller and the Vienna rectifier according to claim 7 are included; the Vienna rectifier is controlled by the controller.

9. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 8. The computer program is executed by the processor to implement the steps of the current distortion suppression method according to any one of claims 1 to 6.

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