A vienna rectifier capable of midpoint balancing

Abstract

A kind of vienna rectifier capable of realizing midpoint balance, the voltage equalization ring output value of the dc side output voltage of vienna rectifier is introduced to compensate the input impedance of vienna rectifier, to achieve the function of affecting the input current and power of vienna rectifier, to realize the output voltage equalization of the dc side of vienna rectifier.

Description

Technical Field

[0001] This invention relates to the field of converter technology, and more specifically to a Vienna rectifier capable of achieving midpoint balance. Background Technology

[0002] The Vienna rectifier is a pulse width modulation rectifier that can accept three-phase alternating current. For example... Figure 1 As shown, the conventional control strategy for Vienna rectifiers requires sampling the input voltage and current on the AC side, obtaining the phase angle of the AC grid using a phase-locked loop, and then converting it to the dq coordinate system using a large number of trigonometric functions for control. Then, a dq decoupling control method is used to control id and iq separately. After reversing dq to the control quantities of the three phases abc, other PWM modulation strategies such as SVM are used to control the power stage.

[0003] However, the entire controller of the Vienna rectifier requires trigonometric functions and coordinate system transformations, and most importantly, the design of the phase-locked loop (PLL). When the three-phase power grid is unbalanced, the ordinary SRF-SPLL is basically inadequate, as the second harmonic on the output dq affects the current control effect. If the higher harmonics and imbalance of the power grid increase, a DDSRF-SPLL is required for positive and negative sequence decoupling control, which further increases the algorithmic complexity of the control strategy. Moreover, the PLL can completely overcome the response speed when the power grid frequency changes. Therefore, in harsh power grid environments with high harmonics and frequency abrupt changes, or in generator applications, the traditional Vienna control strategy is no longer suitable.

[0004] Furthermore, when the loads connected to the first and second output terminals of the Vienna rectifier are unequal, it will cause the voltage of the two DC signals output on the DC side to be unbalanced, resulting in one capacitor voltage being higher and the other capacitor voltage being lower, thereby causing the Vienna rectifier to lose its reliability and stability. Summary of the Invention

[0005] The main technical problem this invention addresses is how to solve the problem of unbalanced DC-side output voltage in Vienna rectifiers.

[0006] According to the first aspect, one embodiment provides a Vienna rectifier capable of achieving midpoint balance, used to convert input three-phase alternating current into a first direct current and a second direct current, wherein the three-phase alternating current includes A-phase alternating current, B-phase alternating current and C-phase alternating current, wherein the Vienna rectifier includes: a switching module and a controller;

[0007] The switching module includes a first switch, a second switch, and a third switch; the first terminal of the first switch is connected to the input terminal of phase A AC power, and the second terminal of the first switch is connected to the neutral line of the Vienna rectifier; the first terminal of the second switch is connected to the input terminal of phase B AC power, and the second terminal of the second switch is connected to the neutral line of the Vienna rectifier; the first terminal of the third switch is connected to the input terminal of phase C AC power, and the second terminal of the third switch is connected to the neutral line of the Vienna rectifier.

[0008] The switching module is used to alternately turn on and off the first, second, and third switches under the control of the first, second, and third control signals output by the controller, so that the Vienna rectifier outputs a first DC power and a second DC power; wherein, the first control signal is used to control the first switch to turn on or off, the second control signal is used to control the second switch to turn on or off, and the third control signal is used to control the third switch to turn on or off.

[0009] The controller is used to acquire the current values ​​of phase A AC, phase B AC, and phase C AC, the output value of the voltage loop of the Vienna rectifier, and the output value of the equalization loop of the DC-side output voltage of the Vienna rectifier; based on the current values ​​of phase A AC, phase B AC, and phase C AC, the output value of the voltage loop of the Vienna rectifier, and the output value of the equalization loop of the DC-side output voltage of the Vienna rectifier 20, it determines a first control quantity, a second control quantity, and a third control quantity; based on the relationship between the first control quantity, the second control quantity, the third control quantity, and a preset PWM carrier, it generates and outputs the first control signal, the second control signal, and the third control signal.

[0010] According to the Vienna rectifier that can achieve midpoint balance according to the above embodiment, the output value of the equalizing ring of the output voltage of the DC side of the Vienna rectifier is introduced to compensate for the input impedance of the Vienna rectifier, so as to affect the input current and power of the Vienna rectifier, thereby realizing the equalization of the output voltage of the DC side of the Vienna rectifier. Attached Figure Description

[0011] Figure 1 A schematic diagram of the existing control strategy for Vienna rectifiers;

[0012] Figure 2 This is a schematic diagram of the structure of a Vienna rectifier according to one embodiment;

[0013] Figure 3 This is a circuit diagram of a Vienna rectifier according to one embodiment;

[0014] Figure 4 A control block diagram of a controller for a Vienna rectifier capable of achieving midpoint balance, according to one embodiment;

[0015] Figure 5 Control block diagram for obtaining the output values ​​of the equalizing loop (Diff) and the voltage loop (Vloop) from the controller.

[0016] Figure 6 This is a simulation diagram of a Vienna rectifier capable of achieving midpoint balance, as provided in this embodiment.

[0017] Figure 7 This is another simulation diagram of a Vienna rectifier that can achieve midpoint balance, as provided in this embodiment. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0019] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0020] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0021] Example 1:

[0022] For Vienna rectifiers, the main objective of achieving high power factor control is to ensure that the phase and frequency of the input current track the voltage phase of the AC input grid, making the rectifier's input impedance resistive, thus achieving in-phase operation of the input current and voltage. Therefore, if the rectifier's input impedance can be made resistive, rather than inductive or capacitive, the input current can automatically follow the grid voltage phase and frequency. From impedance analysis, both inductive and capacitive impedances contain imaginary components; only resistive impedance is real. Therefore, by eliminating the imaginary component in the rectifier's input impedance transfer function during control, the input impedance can be made resistive.

[0023] Please refer to Figure 2 and 3 , Figure 2 This is a schematic diagram of the structure of a Vienna rectifier according to one embodiment. Figure 3 This is a circuit diagram of a Vienna rectifier according to one embodiment. The Vienna rectifier provided in this embodiment is used to convert the three-phase AC power input on its AC side into a first DC power and a second DC power with the same voltage value, and outputs the first DC power and the second DC power through the DC side. The DC side includes a first output terminal Vm1 for outputting the first DC power and a second output terminal Vm2 for outputting the second DC power. A load resistor Rload21 is connected in parallel to the first output terminal Vm1, and a load resistor Rload22 is connected in parallel to the second output terminal. Theoretically, the load resistors Rload21 and Rload22 have the same resistance value. However, in actual cases, when the load resistors Rload21 and Rload22 are not equal, it will cause an imbalance in the voltage of the first DC power and the second DC power.

[0024] In this embodiment of the invention, the input impedance is compensated by the output value of the equalizing ring on the DC side of the Vienna rectifier 20, thereby affecting the input current and power and achieving output voltage balance on the DC side.

[0025] The Vienna rectifier 20 provided in this embodiment includes: an energy storage and energy conversion module 21, a switching module 22, a freewheeling module 23, a filtering module 24, and a controller 25. The energy storage and energy conversion module 21 includes a first energy storage and energy conversion module 211, a second energy storage and energy conversion module 212, and a third energy storage and energy conversion module 213. The first energy storage and energy conversion module 211 receives the A-phase AC power output from the first AC input terminal V1_ac; the second energy storage and energy conversion module 212 receives the B-phase AC power output from the second AC input terminal V2_ac; and the third energy storage and energy conversion module 213 receives the C-phase AC power output from the third AC input terminal V3_ac. The switching module 22 includes a first switch 221, a second switch 222, and a third switch 223. The first switch 221 is connected to the first energy storage and energy conversion module 211, the second switch 222 is connected to the second energy storage and energy conversion module 212, and the third switch 223 is connected to the third energy storage and energy conversion module 213. The freewheeling module 23 includes a first freewheeling module 231, a second freewheeling module 232, and a third freewheeling module 233. The first freewheeling module 231 is connected to the first energy storage and energy conversion module 211, the second freewheeling module 232 is connected to the second energy storage and energy conversion module 212, and the third freewheeling module 233 is connected to the third energy storage and energy conversion module 213. The filtering module 24 includes a first filtering module 241 and a second filtering module 242. The first filtering module 241 is connected in parallel to the first output terminal of the Vienna rectifier 20, and the second filtering module 242 is connected in parallel to the second output terminal of the Vienna rectifier 20. A neutral line is connected between the first output terminal and the second output terminal of the Vienna rectifier 20.

[0026] The first energy storage and energy conversion module 211 is used to convert the AC current input at the first AC input terminal V1_ac into magnetic energy for storage when the first switch 221 is turned on; when the first switch 221 is turned off, it converts the stored magnetic energy into an electrical signal and outputs it to the first output terminal or the second output terminal of the Vienna rectifier 20 through the first freewheeling module 231.

[0027] The second energy storage and energy conversion module 212 is used to convert the AC B input at the second AC input terminal V2_ac into magnetic energy for storage when the second switch 222 is turned on; when the second switch 222 is turned off, it converts the stored magnetic energy into an electrical signal and outputs it to the first or second output terminal of the Vienna rectifier 20 through the second freewheeling module 232.

[0028] The third energy storage and energy conversion module 213 is used to convert the C-phase AC power input at the third AC input terminal V3_ac into magnetic energy for storage when the third switch 223 is turned on; when the third switch 223 is turned off, it converts the stored magnetic energy into an electrical signal and outputs it to the first or second output terminal of the Vienna rectifier 20 through the third freewheeling module 233.

[0029] The first switch 221, the second switch 222, and the third switch 223 each include a first terminal, a second terminal, and a control terminal. The first terminal of the first switch 221 is connected to the output terminal of the first energy storage and energy conversion module 211, the first terminal of the second switch 222 is connected to the output terminal of the second energy storage and energy conversion module 212, and the first terminal of the third switch 223 is connected to the output terminal of the third energy storage and energy conversion module 213. The second terminals of the first switch 221, the second switch 222, and the third switch 223 are all connected to the neutral line of the Vienna rectifier 20. The control terminals of the first switch 221, the second switch 222, and the third switch 223 are all connected to the controller 25.

[0030] like Figure 3 As shown, Figure 3 The diagram shows a circuit of a Vienna rectifier according to one embodiment. The first energy storage and conversion module 211 includes an inductor L21 and a resistor R21. One end of the inductor L21 is connected to the input terminal of the first energy storage and conversion module 211, and the other end of the inductor L21 is connected to one end of the resistor R21. The other end of the resistor R21 is connected to the output terminal of the first energy storage and conversion module 211. The second energy storage and conversion module 212 includes an inductor L22 and a resistor R22, and the third energy storage and conversion module 213 includes an inductor L23 and a resistor R23. The circuit structures of the second and third energy storage and conversion modules 212 and 213 are the same as those of the first energy storage and conversion module 211, and will not be described in detail here.

[0031] It should be noted that the output terminals of the first energy storage and energy conversion module 211, the energy storage and energy conversion module 212, and the third energy storage and energy conversion module 213 are respectively connected to a first current sampler A21, a second current sampler A22, a third current sampler A23, and a low-pass filter LPF2. The first current sampler A21 is used to acquire the current signal of phase A AC power; the second current sampler A22 is used to acquire the current signal of phase B AC power; the third current sampler A23 is used to acquire the current signal of phase C AC power; the low-pass filter LPF2 is used to filter the current signals of phase A AC power, phase B AC power, and phase C AC power, and then output the current values ​​of phase A AC power, phase B AC power, and phase C AC power to the controller 25.

[0032] The first switch 221 includes transistors Q21 and Q22; transistor Q21 includes a first terminal, a second terminal, and a control terminal, and transistor Q22 includes a first terminal, a second terminal, and a control terminal; the first terminal of transistor Q21 is connected to the first terminal of the first switch 221, the second terminal of transistor Q21 is connected to the second terminal of transistor Q22, and the first terminal of transistor Q22 is connected to the second terminal of the first switch 221; the control terminals of both transistors Q21 and Q22 are connected to the control terminal of the first switch 221.

[0033] The second switch 222 includes a transistor Q23 and a fourth transistor Q24; the transistor Q23 includes a first terminal, a second terminal, and a control terminal, and the fourth transistor Q24 includes a first terminal, a second terminal, and a control terminal; the first terminal of transistor Q23 is connected to the first terminal of the second switch 222, the second terminal of transistor Q23 is connected to the second terminal of the fourth transistor Q24, and the first terminal of the fourth transistor Q24 is connected to the second terminal of the second switch; the control terminals of both transistor Q23 and the fourth transistor Q24 are connected to the control terminal of the second switch 222.

[0034] The third switch 223 includes a fifth transistor Q25 and a sixth transistor Q26; the fifth transistor Q25 includes a first terminal, a second terminal, and a control terminal, and the sixth transistor Q26 includes a first terminal, a second terminal, and a control terminal; the first terminal of the fifth transistor Q25 is connected to the first terminal of the third switch 223, the second terminal of the fifth transistor Q25 is connected to the second terminal of the sixth transistor Q26, and the first terminal of the fifth transistor Q25 is connected to the second terminal of the third switch 223; the control terminals of both the fifth transistor Q25 and the sixth transistor Q26 are connected to the control terminal of the third switch 223.

[0035] The first freewheeling module 231 includes diodes D21 and D22. The anode of diode D21 and the cathode of diode D22 are connected to the output terminal of the first energy storage and energy conversion module 211. The cathode of diode D21 is connected to the first output terminal Vm1 of the Vienna rectifier 20, and the anode of diode D22 is connected to the second output terminal Vm2 of the Vienna rectifier 20. The second freewheeling module 232 includes diodes D23 and D24, and the third freewheeling module 233 includes diodes D25 and D26. The circuit structures of the second freewheeling module 232 and the third freewheeling module 233 are the same as those of the first freewheeling module 231, and will not be described in detail here.

[0036] The first filter module 241 includes a capacitor C21 and a resistor R22. One end of the capacitor C21 is connected to the first output terminal Vm1 of the Vienna rectifier 20, and the other end of the capacitor C21 is connected to one end of the resistor R22. The other end of the resistor R22 is connected to the neutral line of the Vienna rectifier 20. The second filter module 242 includes a capacitor C22 and a resistor R23. One end of the capacitor C22 is connected to the second output terminal Vm2 of the Vienna rectifier 20, and the other end of the capacitor C22 is connected to one end of the resistor R23. The other end of the resistor R23 is connected to the neutral line of the Vienna rectifier 20.

[0037] It should be noted that the transistor in this application is a three-terminal transistor, with its three terminals being the control terminal, the first terminal, and the second terminal. The transistor can be a bipolar transistor (BPT) or a field-effect transistor (FET), etc. For example, when the transistor is a BPT, its control terminal refers to the base of the BPT, the first terminal can be the collector or emitter of the BPT, and the corresponding second terminal can be the emitter or collector of the BPT; when the transistor is a FET, its control terminal refers to the gate of the FET, the first terminal can be the drain or source of the FET, and the corresponding second terminal can be the source or drain of the FET.

[0038] The controller 25 is used to acquire the current values ​​of phase A AC, phase B AC, phase C AC, the output value of the voltage loop of the Vienna rectifier 20, and the output value of the equalization loop of the DC-side output voltage of the Vienna rectifier 20; based on the current values ​​of phase A AC, phase B AC, phase C AC, the output value of the voltage loop of the Vienna rectifier 20, and the output value of the equalization loop of the DC-side output voltage of the Vienna rectifier 20, it determines the first control quantity, the second control quantity, and the third control quantity; based on the relationship between the first control quantity, the second control quantity, the third control quantity and the preset PWM carrier, it generates and outputs the first control signal, the second control signal, and the third control signal.

[0039] The first control quantity, the second control quantity, and the third control quantity of the Vienna rectifier 20 will be described in detail below. Since the calculation methods of the first control quantity, the second control quantity, and the third control quantity are similar, this embodiment will take the first control quantity as an example for detailed description.

[0040] The ratio of the sum of the current value of phase A AC and the output value of the voltage equalization loop to the output value of the voltage loop is used as the first control quantity, i.e., the first control quantity. iLa is the current signal of phase A AC on inductor L11, Hlpf(s) is the transfer function of low-pass filter LPF2, Diff is the output value of the equalization loop of the DC side output voltage of Vienna rectifier 20, and Vloop is the output value of the voltage loop of Vienna rectifier 20.

[0041] In some embodiments, the first control value may be too large or too small, which could damage the transistor due to the maximum or minimum duty cycle of the PWM output. Therefore, this embodiment performs amplitude limiting on the first control value. In this embodiment, the first control value is a value greater than 0 and less than 1, and the optimal value is greater than or equal to 0.05 and less than or equal to 0.995. The second and third control values ​​also require the same amplitude limiting treatment, which will not be described in detail here.

[0042] In one embodiment, a first control signal is generated and output based on the relationship between a first control quantity and a preset PWM carrier wave, including:

[0043] The first control quantity is multiplied by a preset switching cycle time to obtain the first core control quantity. Within each cycle of the preset PWM carrier, the time period during which the preset PWM carrier is greater than or equal to the first core control quantity is taken as the off-time period of the first switch 221, and the time period during which the preset PWM carrier is less than the first core control quantity is taken as the on-time period of the first switch 221. Based on the off-time and on-time periods of the first switch 221, a first control signal for each cycle is generated and output to the control terminal of the first switch 221. Specifically, a first control signal for controlling the first switch 221 to turn off is generated during the off-time period of the first switch, and a first control signal for controlling the first switch 221 to turn on is generated during the on-time period of the first switch 221.

[0044] The second and third control signals are generated in the same way as the first control signal, and will not be described in detail here.

[0045] In this embodiment, the control strategy of the controller 25 can be implemented using digital or analog circuits. This invention is not limited to one implementation method; please refer to [the relevant documentation]. Figure 4 , Figure 4This is a control block diagram of the controller 25 of a Vienna rectifier 20 according to one embodiment. This embodiment is also described using the first control signal as an example. The controller 25 includes: an adder ADD1, an absolute value extractor Abs1, a divider Divide1, a limiter Saturation1, a proportionalizer TBPRD1, a PWM carrier generator PWM_ramp, and a comparator Relational Operator1. The adder ADD1 receives inputs iLa and Diff. The output of the adder ADD1 is connected to the input of the absolute value extractor Abs1. The output of the absolute value extractor Abs1 is connected to the first input of the divider Divide1. The second input of the divider Divide1 is input to Vloop. The output of the divider Divide1 is connected to the input of the limiter Saturation1. The output of the limiter Saturation1 is connected to the input of the proportionalizer TBPRD1. The output of the proportionalizer TBPRD1 is connected to the first input of the comparator Relational Operator1. The second input terminal of 1 is connected to the output terminal of the PWM carrier generator PWM_ramp, and the output terminal of the comparator Relational Operator 1 outputs the first control signal PWM_A.

[0046] The above is the control block diagram for generating the first control signal. The second and third control signals are similar to the first control signal, and will not be described in detail here.

[0047] In this embodiment, as Figure 5 As shown in (a), the output value Diff of the equalizing ring of the DC-side output voltage of Vienna rectifier 20 is... Figure 3 The difference between the voltage Vmo1 output from the first output terminal Vm1 and the voltage Vmo2 output from the second output terminal Vm2 is the output value after passing through the zero-order hold ZOH1 and the PI controller 1; for example Figure 5 As shown in (b), the output value Vloop of the Vienna rectifier 20 is the sum of the voltage Vmo1 output from the first output terminal Vm1 and the voltage Vmo2 output from the second output terminal Vm2, after passing through the zero-order hold ZOH2, and the difference between the set voltage Vo_set and the output value after passing through the PI controller 2.

[0048] Please refer to Figure 5 , Figure 5The diagram below shows a simulation of the Vienna rectifier 20. In CH1, A, B, and C are the three-phase input voltage signals, respectively. In CH2, DiffA, DiffB, and DiffC are the first, second, and third control quantities output by the controller 25, respectively. PWM_ramp is the preset PWM carrier wave. In CH3, PWM_A, PWM_B, and PWM_C are the control signals for the first, second, and third switches, respectively.

[0049] Please refer to Figure 6 , Figure 6 This describes the operation of the Vienna rectifier 20 under a midpoint voltage balancing strategy, where the positive DC bus load decreases while the negative DC bus load remains unchanged, after switching from load balancing to a balanced operation. In CH1, Vmo1 is the positive DC bus voltage, and Vmo2 is the negative DC bus voltage. In CH2, iLa is the A-phase input current signal, and Diff is the output value of the voltage equalization loop, which is 0 when the load is balanced and adjusted to -4.2A when the load is unbalanced. CH3 shows the output of iLa + Diff, where the positive peak value is weakened and the negative peak value is increased, thus affecting the input impedance at different AC phases. CH4 shows the Doff of phase A.

[0050] Please refer to Figure 7 , Figure 7 This is the case where the Vienna rectifier 20 transitions from an unbalanced load to a balanced load. As you can see, the output value of the equalizing ring decreases to 0, no longer affecting the input impedance and power.

[0051] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A Vienna rectifier capable of achieving midpoint balance, used to convert input three-phase alternating current into a first direct current and a second direct current, wherein the three-phase alternating current includes phase A alternating current, phase B alternating current, and phase C alternating current, characterized in that, The Vienna rectifier includes: a switching module and a controller; The switching module includes a first switch, a second switch, and a third switch; the first terminal of the first switch is connected to the input terminal of phase A AC power, and the second terminal of the first switch is connected to the neutral line of the Vienna rectifier; the first terminal of the second switch is connected to the input terminal of phase B AC power, and the second terminal of the second switch is connected to the neutral line of the Vienna rectifier; the first terminal of the third switch is connected to the input terminal of phase C AC power, and the second terminal of the third switch is connected to the neutral line of the Vienna rectifier. The switching module is used to alternately turn on and off the first, second, and third switches under the control of the first, second, and third control signals output by the controller, so that the Vienna rectifier outputs a first DC power and a second DC power; wherein, the first control signal is used to control the first switch to turn on or off, the second control signal is used to control the second switch to turn on or off, and the third control signal is used to control the third switch to turn on or off. The controller is used to acquire the current values ​​of phase A, phase B, and phase C AC power, the output value of the voltage loop of the Vienna rectifier, and the output value of the equalization loop of the DC-side output voltage of the Vienna rectifier; based on the current values ​​of phase A, phase B, and phase C AC power, the output value of the voltage loop of the Vienna rectifier, and the output value of the equalization loop of the DC-side output voltage of the Vienna rectifier, it determines a first control quantity, a second control quantity, and a third control quantity; based on the relationship between the first control quantity, the second control quantity, the third control quantity, and a preset PWM carrier wave, it generates and outputs the first control signal, the second control signal, and the third control signal. The determination of the first control quantity, the second control quantity, and the third control quantity based on the current values ​​of the A-phase AC power, the B-phase AC power, and the C-phase AC power, the output value of the voltage loop of the Vienna rectifier, and the output value of the equalizing loop of the DC-side output voltage of the Vienna rectifier, includes: The ratio of the sum of the current value of phase A AC and the output value of the voltage equalization ring to the output value of the voltage ring is used as the first control quantity; The ratio of the sum of the current value of the B-phase AC power and the output value of the equalizing ring to the output value of the voltage ring is used as the second control quantity; The ratio of the sum of the current value of the C-phase AC power and the output value of the voltage equalization ring to the output value of the voltage ring is used as the third control quantity; Among them, the first control quantity, the second control quantity, and the third control quantity all satisfy the condition of being greater than 0 and less than 1; The generation and output of the first control signal, the second control signal, and the third control signal based on the relationship between the first control quantity, the second control quantity, the third control quantity, and the preset PWM carrier includes: Multiply the first control quantity by the preset switching cycle time to obtain the first core control quantity; Within each cycle of the preset PWM carrier, the time period during which the preset PWM carrier is greater than or equal to the first core control quantity is taken as the off time period of the first switch, and the time period during which the preset PWM carrier is less than the first core control quantity is taken as the on time period of the first switch. Based on the off-time period and on-time period of the first switch, generate and output the first control signal of each cycle to the control terminal of the first switch; Specifically, a first control signal for controlling the first switch to turn off is generated during the off-time period of the first switch, and a first control signal for controlling the first switch to turn on is generated during the on-time period of the first switch. Multiply the second control quantity by the preset switching cycle time to obtain the second core control quantity; Within each cycle of the preset PWM carrier, the time period during which the preset PWM carrier is greater than or equal to the second core control quantity is taken as the off time period of the second switch, and the time period during which the preset PWM carrier is less than the second core control quantity is taken as the on time period of the second switch. Based on the off-time period and on-time period of the second switch, generate and output the second control signal of each cycle to the control terminal of the second switch; Specifically, a second control signal is generated during the off-time period of the second switch to control the second switch to be off, and a second control signal is generated during the on-time period of the second switch to control the second switch to be on. The process of generating and outputting the third control signal to the control terminal of the third switch based on the relationship between the third control quantity and the preset PWM carrier includes: Multiply the third control quantity by the preset switching cycle time to obtain the third core control quantity; Within each cycle of the preset PWM carrier, the time period during which the preset PWM carrier is greater than or equal to the third core control quantity is taken as the off time period of the third switch, and the time period during which the preset PWM carrier is less than the third core control quantity is taken as the on time period of the third switch. Based on the off-time period and on-time period of the third switch, a third control signal for each cycle is generated and output to the control terminal of the third switch. Specifically, a third control signal is generated during the off-time period of the third switch to control the third switch to turn off, and a third control signal is generated during the on-time period of the third switch to control the third switch to turn on.

2. The Vienna rectifier as described in claim 1, characterized in that, The controller includes: a first control module; the first control module includes: an adder ADD1, an absolute value extractor Abs1, a divider Divide1, a limiter Saturation1, a proportionalizer TBPRD1, a comparator Relational Operator1, and a PWM carrier generator PWM_ramp; The adder ADD1 is input to the current value of the A-phase AC power and the output value of the equalizing ring, and the output terminal of the adder ADD1 is connected to the input terminal of the absolute value generator Abs1. The output of the absolute value generator Abs1 is connected to the first input of the divider Divide1. The voltage loop output value is input to the second input terminal of the divider Divide1, and the output terminal of the divider Divide1 is connected to the input terminal of the limiter Saturation1. The output of the limiter Saturation1 is connected to the input of the proportionalizer TBPRD1; The output of the proportionalizer TBPRD1 is connected to the first input of the comparator Relational Operator1. The second input terminal of the comparator Relational Operator 1 is connected to the output terminal of the PWM carrier generator PWM_ramp, and the output terminal of the comparator Relational Operator 1 outputs the first control signal.

3. The Vienna rectifier as described in claim 1, characterized in that, Also includes: Energy storage and energy conversion modules, freewheeling modules, and filtering modules; The energy storage and energy conversion module includes a first energy storage and energy conversion module, a second energy storage and energy conversion module, and a third energy storage and energy conversion module; The current-continuing module includes: a first current-continuing module, a second current-continuing module, and a third current-continuing module; the filtering module includes: a first filtering module and a second filtering module. The first energy storage and energy conversion module is used to convert the A-phase AC current into magnetic energy for storage when the first switch is turned on; and to convert the stored magnetic energy into an electrical signal and output it to the first output terminal or the second output terminal of the Vienna rectifier through the first freewheeling module when the first switch is turned off. The second energy storage and energy conversion module is used to convert the B-phase AC power into magnetic energy for storage when the second switch is turned on; and to convert the stored magnetic energy into an electrical signal and output it to the first or second output terminal of the Vienna rectifier through the second freewheeling module when the second switch is turned off. The third energy storage and energy conversion module is used to convert the C-phase AC current into magnetic energy for storage when the third switch is turned on; when the third switch is turned off, the stored magnetic energy is converted into an electrical signal and output to the first or second output terminal of the Vienna rectifier through the third freewheeling module.

4. The Vienna rectifier as described in claim 1, characterized in that, Also includes: First current sampler, second current sampler, third current sampler, and low-pass filter; The first current sampler is used to acquire the current signal of the A-phase AC power; The second current sampler is used to acquire the current signal of the B-phase AC power; The third current sampler is used to acquire the current signal of the C-phase AC power. The low-pass filter is used to filter the current signals of the A-phase AC power, the B-phase AC power, and the C-phase AC power, and then output the current values ​​of the A-phase AC power, the AC values ​​of the B-phase AC power, and the AC values ​​of the C-phase AC power to the controller.

5. The Vienna rectifier as described in claim 1, characterized in that, The first switch includes transistor Q21 and transistor Q22; transistor Q21 includes a first electrode, a second electrode, and a control electrode, and transistor Q22 includes a first electrode, a second electrode, and a control electrode; the first electrode of transistor Q21 is connected to the first terminal of the first switch, the second electrode of transistor Q21 is connected to the second electrode of transistor Q22, and the first electrode of transistor Q22 is connected to the second terminal of the first switch 221; the control electrodes of both transistor Q21 and transistor Q22 are connected to the control terminal of the first switch 221. The second switch includes a transistor Q23 and a fourth transistor Q24; transistor Q23 includes a first terminal, a second terminal, and a control terminal, and the fourth transistor Q24 includes a first terminal, a second terminal, and a control terminal; the first terminal of transistor Q23 is connected to the first terminal of the second switch 222, the second terminal of transistor Q23 is connected to the second terminal of the fourth transistor Q24, and the first terminal of the fourth transistor Q24 is connected to the second terminal of the second switch; the control terminals of both transistor Q23 and the fourth transistor Q24 are connected to the control terminal of the second switch. The third switch includes a fifth transistor Q25 and a sixth transistor Q26; the fifth transistor Q25 includes a first terminal, a second terminal, and a control terminal, and the sixth transistor Q26 includes a first terminal, a second terminal, and a control terminal; the first terminal of the fifth transistor Q25 is connected to the first terminal of the third switch 223, the second terminal of the fifth transistor Q25 is connected to the second terminal of the sixth transistor Q26, and the first terminal of the fifth transistor Q25 is connected to the second terminal of the third switch; the control terminals of both the fifth transistor Q25 and the sixth transistor Q26 are connected to the control terminal of the third switch.

6. The Vienna rectifier as described in claim 3, characterized in that, The first freewheeling module includes diodes D21 and D22. The anode of diode D21 and the cathode of diode D22 are connected to the output terminal of the first energy storage and energy conversion module 211. The cathode of diode D21 is connected to the first output terminal of the Vienna rectifier, and the anode of diode D22 is connected to the second output terminal of the Vienna rectifier.

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