Method and system for controlling a silicon carbide device air conditioner compressor drive

Abstract

The application belongs to the technical field of power electronics, and relates to a control method and system for a silicon carbide device air conditioner compressor driving device, the method comprising: performing two-phase static coordinate transformation on three-phase grid voltage and three-phase grid current, and performing phase-locked processing on the grid voltage to obtain a grid voltage angle signal; performing rotating coordinate transformation on the grid voltage and the grid current according to the voltage angle signal; generating two-phase linear signals according to an actual DC bus voltage, a dq-axis grid voltage and a dq-axis grid current; performing three-phase static coordinate transformation on the two-phase linear signals to obtain three-phase modulation signals of a grid-side driving converter based on the grid voltage angle signal and the actual DC bus voltage; and generating driving signals of the grid-side and compressor-side driving converters according to modulation signals of the grid-side and compressor-side driving converters and four different carrier signals. The application has high control precision, and can improve the efficiency, reliability and adaptability of the air conditioner compressor driving device.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology, and relates to air conditioner compressor control technology. Specifically, it relates to a control method and system for a silicon carbide device air conditioner compressor drive device. Background Technology

[0002] The air conditioner compressor drive inverter is the core power control unit of a variable frequency air conditioning system. Its core function is to convert the mains frequency AC power input from the grid into AC power with adjustable frequency and voltage through a two-step "rectification-inversion" process. This AC power then drives the variable frequency air conditioner compressor to adjust its operating state according to actual cooling / heating needs. Compared to traditional fixed frequency air conditioners, variable frequency air conditioners equipped with this drive inverter can maintain low-speed operation of the compressor under low load conditions through precise frequency control. This avoids frequent switching between compressor shutdown and full-load operation, significantly reducing overall energy consumption and effectively reducing the frequency of compressor start-stop, improving temperature control accuracy and quiet operation. It is a key component for achieving efficient, stable, and comfortable operation in variable frequency air conditioners.

[0003] Currently, the power switching and rectifier devices in air conditioner compressor drive inverters mostly employ insulated-gate bipolar transistors (IGBTs) and silicon-based Schottky diodes made from silicon (Si) materials. After long-term technological iterations, the performance of silicon-based power devices has gradually approached the theoretical limits of the material itself. Significant breakthroughs in key indicators such as switching losses, high-temperature resistance, and voltage withstand ratings are difficult to achieve, failing to meet the demands of variable frequency air conditioners for higher energy efficiency, smaller size, and wider adaptability to various operating conditions.

[0004] In recent years, silicon carbide (SiC) power semiconductor devices have emerged as a superior alternative for high-efficiency power devices in fields such as new energy and industrial control due to their excellent material properties. Among them, SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) offer advantages over traditional silicon-based IGBTs, including faster switching speeds, lower switching losses, and superior high-temperature resistance. Silicon carbide Schottky diodes, compared to silicon-based Schottky diodes, also exhibit higher voltage ratings and lower reverse recovery losses. Applying SiC MOSFETs and silicon carbide Schottky diodes to air conditioner compressor drive inverters is expected to significantly improve the inverter's energy conversion efficiency and operational stability.

[0005] However, the ultra-high switching speed of SiC MOSFETs also brings new technical challenges. In the circuit topology and control strategy of traditional air conditioner drive inverters, directly applying SiC MOSFETs results in extremely high voltage change rates (dv / dt) and current change rates (di / dt) in the circuit. Due to non-ideal factors such as parasitic capacitance and inductance in the circuit, overvoltage spikes and current surges are easily triggered, and in severe cases, this can lead to shoot-through short circuits in the inverter bridge arms, significantly reducing the operational reliability of the air conditioner compressor drive inverter and hindering the large-scale application of silicon carbide power devices in the air conditioning field. Summary of the Invention

[0006] To address the aforementioned problems of low reliability in existing technologies, this invention provides a control method and system for a silicon carbide device air conditioner compressor drive device, which offers high control precision and improves the efficiency, reliability, and adaptability of the air conditioner compressor drive device.

[0007] In a first aspect, the present invention provides a control method for a silicon carbide device air conditioner compressor drive device, the specific steps of which are as follows:

[0008] The static coordinate transformation steps are as follows: Transform the three-phase grid voltage and three-phase grid current into grid voltage and grid current in a two-phase static coordinate system;

[0009] Voltage phase-locking steps: Phase-locking is performed on the grid voltage in the two-phase stationary coordinate system to obtain the grid voltage angle signal;

[0010] Rotating coordinate transformation steps: Based on the voltage angle signal, transform the grid voltage and grid current in the two-phase stationary coordinate system into the grid voltage and grid current in the two-phase rotating coordinate system;

[0011] Linear signal generation steps: Generate a two-phase linear signal by performing PI control based on the actual DC bus voltage, grid voltage and grid current in the two-phase rotating coordinate system;

[0012] Grid-side modulation signal generation steps: Based on the grid voltage angle signal and the actual DC bus voltage, the two-phase linear signal is transformed into three-phase stationary coordinates to obtain the three-phase modulation signal for the grid-side drive converter;

[0013] Setting steps: Set four isosceles triangular carrier signals with the same frequency but different amplitude ranges as carrier signals, and set the three-phase modulation signal for driving the compressor-side converter;

[0014] Drive signal generation steps: Generate the i-phase rectifier drive signal of the grid-side drive converter based on the i-phase modulation signal and four carrier signals, i=a,b,c; Generate the i-phase inverter drive signal of the compressor-side drive converter based on the i-phase modulation signal and four carrier signals.

[0015] In conjunction with the first aspect, in some embodiments, the method for transforming the three-phase grid voltage into the grid voltage in a two-phase stationary coordinate system during the static coordinate transformation is as follows:

[0016] Phase a grid voltage U a Apply phase b grid voltage U b Multiply by the first set coefficient and add the c-phase grid voltage U c Multiply by the first set coefficient, then multiply by the second set coefficient to obtain the grid voltage U. α ;

[0017] phase b grid voltage U b Multiply by the third set coefficient and add the c-phase grid voltage U c After multiplying by the third set factor, multiply by the second set factor to obtain the grid voltage U. β ;

[0018] The method for transforming three-phase grid current into grid current in a two-phase stationary coordinate system is as follows:

[0019] Phase a grid current I a Add phase b grid current I b Multiply by the first set coefficient and add the c-phase grid current I c Multiply by the first set coefficient, then multiply by the second set coefficient to obtain the grid current I. α ;

[0020] b-phase grid current I b Multiply by the third set coefficient and add the c-phase grid current I c After multiplying by the third set factor, multiply by the second set factor to obtain the grid current I. β .

[0021] In conjunction with the first aspect, in some embodiments, the method for obtaining the grid voltage angle signal by performing phase-locking processing on the grid voltage in the two-phase stationary coordinate system in the voltage phase-locking step is as follows:

[0022] Grid voltage U α The square of the grid voltage U β The first intermediate value is obtained by adding the squares together and then taking the square root.

[0023] Grid voltage U α Divide by the first intermediate value of the grid voltage angle signal sinθ, and the grid voltage U β Divide by the first intermediate value of the grid voltage angle signal cosθ, where θ is the grid voltage angle.

[0024] In conjunction with the first aspect, in some embodiments, the method for transforming the grid voltage in the two-phase stationary coordinate system to the grid voltage in the two-phase rotating coordinate system based on the voltage angle signal in the rotating coordinate transformation step is as follows:

[0025] Grid voltage U α Multiply by cosθ and grid voltage U β Multiply by sinθ and add them together to obtain the d-axis grid voltage U in the two-phase rotating coordinate system. d ;

[0026] Grid voltage U α Multiply by sinθ, multiply by the fourth set coefficient, and then multiply by the grid voltage U. β Multiply by cosθ and add them together to obtain the q-axis grid voltage U in the two-phase rotating coordinate system. q ;

[0027] The method for transforming grid current in a two-phase stationary coordinate system into grid current in a two-phase rotating coordinate system based on voltage angle signals is as follows:

[0028] Grid current I α Multiply by cosθ and grid current I β Multiply by sinθ and add them together to obtain the d-axis grid current I in the two-phase rotating coordinate system. d ;

[0029] Grid current I α Multiply by sinθ, multiply by the fourth set coefficient, and multiply by the grid current I. β Multiplying by cosθ and adding them together, we obtain the q-axis grid current I in the two-phase rotating coordinate system. q .

[0030] In conjunction with the first aspect, in some embodiments, the method for generating a two-phase linear signal in the linear signal generation step is as follows:

[0031] Set the desired DC bus voltage U dc ' The desired DC bus voltage U dc ' Reduce actual DC bus voltage U dc The difference is used to obtain the first intermediate value through PI control. The negative value of the first intermediate value is then subtracted from the d-axis grid current I. d The error value is processed by PI control to obtain a second intermediate value, which is then compared with the d-axis grid voltage U. d Adding them together yields the linear signal x of the d-axis. d ;

[0032] Set the desired grid current I along the q-axis q ' The desired grid current I along the q-axis q ' Reduce q-axis grid current I q The difference is used to obtain a third intermediate value through PI control. This third intermediate value is then compared with the q-axis grid voltage U. q Adding them together yields the q-axis linear signal x. q .

[0033] In conjunction with the first aspect, in some embodiments, the method for obtaining the three-phase modulation signal of the grid-side drive converter by performing a three-phase stationary coordinate transformation in the grid-side modulation signal generation step is as follows:

[0034] The linear signal x of the d-axis d Multiply by the fifth set coefficient and then divide by the actual DC bus voltage U dc Obtain the linear signal x d ' The q-axis linear signal x q Multiply by the fifth set coefficient and then divide by the actual DC bus voltage U dc Obtain the linear signal x q ' ;

[0035] linear signal x d ' Multiply by cosθ and subtract the linear signal x q ' Multiplying by sinθ yields the a-phase modulation signal x of the grid-side drive converter. a ;

[0036] Multiply sinθ by the third set coefficient, add cosθ by the first set coefficient, and then multiply by the linear signal x. d ' The first signal x1 is obtained. Then, sinθ is multiplied by a first set coefficient, cosθ is multiplied by a third set coefficient, and finally multiplied by the linear signal x. q ' The second signal x2 is obtained, and the first signal x1 is added to the second signal x2 to obtain the b-phase modulation signal x of the grid-side drive converter. b ;

[0037] Multiply cosθ by the first set coefficient, subtract sinθ by the third set coefficient, and then multiply by the linear signal x. d ' The third signal x3 is obtained. Sinθ is multiplied by the sixth set coefficient, then cosθ is multiplied by the third set coefficient, and finally multiplied by the linear signal x. q ' The fourth signal x4 is obtained; the third signal x3 is added to the fourth signal x4 to obtain the c-phase modulation signal x of the grid-side drive converter. c .

[0038] In conjunction with the first aspect, in some embodiments, the method for generating the i-phase rectifier drive signal of the grid-side drive converter in the drive signal generation step is as follows:

[0039] Determine the i-phase modulation signal x of the grid-side drive converter i If the value is greater than or equal to 0, then the first layer of superimposed carrier signal x is obtained.i1 The first carrier signal is carrier1, and the second superimposed carrier is x. i2 If the second carrier signal is carrier2, then the first layered carrier signal x is obtained. i1 The third carrier signal is carrier3, and the second layer of superimposed carrier signal is x. i2 The fourth carrier signal is carrier4;

[0040] The i-phase modulation signal x of the grid-side drive converter i After passing through the SIGN function, multiply by -0.5, and then add the i-phase modulation signal x of the grid-side drive converter. i Obtain the modulated signal x i ' ;

[0041] Determine the i-phase modulation signal x of the grid-side drive converter i Is it greater than or equal to the first layer carrier signal x? i1 If yes, the drive signal PWMXi1 is high; otherwise, the drive signal PWMXi1 is low.

[0042] Determine the i-phase modulation signal x of the grid-side drive converter i Is it less than or equal to the second-layer superimposed carrier signal x? i2 If yes, the drive signal PWMXi2 is high; otherwise, the drive signal PWMXi2 is low.

[0043] Determine the i-phase modulation signal x of the grid-side drive converter i If the value is greater than or equal to 0, then drive signal PWMXi3 is at a high level and drive signal PWMXi4 is at a low level; otherwise, drive signal PWMXi3 is at a low level and drive signal PWMXi4 is at a high level.

[0044] Determine the modulated signal x i ' If the value is greater than or equal to 0, then drive signals PWMXi5 and PWMXi6 are the inverted signals of drive signal PWMXi1; otherwise, drive signals PWMXi5 and PWMXi6 are the inverted signals of drive signal PWMXi2.

[0045] In conjunction with the first aspect, in some embodiments, the method for generating the i-phase inverter drive signal for the compressor-side drive converter in the drive signal generation step is as follows:

[0046] Determine the i-phase modulation signal y of the compressor-side drive converter i If the value is greater than or equal to 0, then the third-layer superimposed carrier signal y is obtained. i1The first carrier signal is carrier1, and the fourth superimposed carrier is y. i2 If the second carrier signal is carrier2, then the third superimposed carrier signal y is obtained. i1 The third carrier signal is carrier3, and the fourth superimposed carrier signal is y. i2 The fourth carrier signal is carrier4;

[0047] The i-phase modulation signal y of the compressor-side drive converter i After passing through the SIGN function, multiply by -0.5, and then add the i-phase modulation signal y of the compressor-side drive converter. i Obtain the modulated signal y i ' ;

[0048] Determine the i-phase modulation signal y of the compressor-side drive converter i Is it greater than or equal to the third-layer superimposed carrier signal y? i1 If yes, the drive signal PWMYi1 is high; otherwise, the drive signal PWMYi1 is low.

[0049] Determine the i-phase modulation signal y of the compressor-side drive converter i Is it less than or equal to the fourth layer superimposed carrier signal y? i2 If yes, the drive signal PWMYi2 is high; otherwise, the drive signal PWMYi2 is low.

[0050] Determine the i-phase modulation signal y of the compressor-side drive converter i If the value is greater than or equal to 0, then drive signal PWMYi3 is high and drive signal PWMYi4 is low; otherwise, drive signal PWMYi3 is low and drive signal PWMYi4 is high.

[0051] Determine the modulated signal y i ' If the value is greater than or equal to 0, then the driving signals PWMYi5 and PWMYi6 are the inverted signals of the driving signal PWMYi1; otherwise, the driving signals PWMYi5 and PWMYi6 are the inverted signals of the driving signal PWMYi2.

[0052] In a second aspect, the present invention provides a control system for a silicon carbide device air conditioner compressor drive device, used to implement the control method for the silicon carbide device air conditioner compressor drive device described in the first aspect of the present invention, comprising:

[0053] The acquisition module is used to acquire three-phase grid voltage, three-phase grid current, and actual DC bus voltage.

[0054] The stationary coordinate transformation module is used to transform three-phase grid voltage and three-phase grid current into grid voltage and grid current in a two-phase stationary coordinate system;

[0055] The voltage phase-locked module is used to perform phase-locking processing on the grid voltage in a two-phase stationary coordinate system to obtain the grid voltage angle signal.

[0056] The rotating coordinate transformation module is used to transform the grid voltage and grid current in a two-phase stationary coordinate system into the grid voltage and grid current in a two-phase rotating coordinate system based on the voltage angle signal.

[0057] The linear signal generation module is used to generate a two-phase linear signal based on the actual DC bus voltage, the grid voltage and grid current in the two-phase rotating coordinate system using PI control.

[0058] The grid-side modulation signal generation module is used to perform a three-phase static coordinate transformation on the two-phase linear signal based on the grid voltage angle signal and the actual DC bus voltage to obtain the three-phase modulation signal for the grid-side drive converter.

[0059] The setting module is used to set four isosceles triangular carrier signals with the same frequency but different amplitude ranges as carrier signals, and to set the three-phase modulation signal for driving the compressor-side converter.

[0060] The drive signal generation module is used to generate the i-phase rectifier drive signal of the grid-side drive converter based on the i-phase modulation signal and four carrier signals of the grid-side drive converter, i=a,b,c; and to generate the i-phase inverter drive signal of the compressor-side drive converter based on the i-phase modulation signal and four carrier signals of the compressor-side drive converter.

[0061] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0062] The control method and system for air conditioner compressor drive device provided by this invention, through precise control of multi-stage coordinate transformation and differentiated drive design of multi-carrier signals, adapts to the high-speed switching characteristics of devices such as silicon carbide MOSFETs, while taking into account the coordinated control of grid-side rectification and compressor-side inverter. It not only fully utilizes the performance advantages of low loss and high temperature resistance of silicon carbide devices, but also completely solves the reliability problems caused by high-speed switching such as overvoltage, overshoot, and short circuit from the control level, achieving multiple technical effects of high efficiency, high reliability, high adaptability, and high control precision in air conditioner compressor drive device. Attached Figure Description

[0063] Figure 1 This is a circuit diagram of the silicon carbide device air conditioner compressor drive device according to an embodiment of the present invention;

[0064] Figure 2This is a flowchart of the control method for the air conditioner compressor drive device of silicon carbide device according to an embodiment of the present invention;

[0065] Figure 3 This is a schematic diagram of the static coordinate transformation of three-phase power grid voltage according to an embodiment of the present invention;

[0066] Figure 4 This is a schematic diagram illustrating the principle of static coordinate transformation of three-phase power grid current according to an embodiment of the present invention.

[0067] Figure 5 This is a schematic diagram illustrating the principle of two-phase power grid voltage phase-locked loop processing according to an embodiment of the present invention.

[0068] Figure 6 This is a schematic diagram illustrating the principle of two-phase grid voltage rotation coordinate transformation according to an embodiment of the present invention.

[0069] Figure 7 This is a schematic diagram illustrating the principle of two-phase power grid current rotation coordinate transformation according to an embodiment of the present invention;

[0070] Figure 8 This is a schematic diagram illustrating the principle of two-phase linear signal generation in an embodiment of the present invention.

[0071] Figure 9 This is a schematic diagram illustrating the generation principle of the network-side modulation signal in an embodiment of the present invention.

[0072] Figure 10 This is a schematic diagram illustrating the generation of the i-phase inverter drive signal in the grid-side drive converter according to an embodiment of the present invention.

[0073] Figure 11 This is a schematic diagram illustrating the generation of three-phase inverter drive signals in a grid-side drive converter according to an embodiment of the present invention.

[0074] Figure 12 This is a schematic diagram illustrating the generation of the i-phase inverter drive signal for the compressor-side drive converter in an embodiment of the present invention.

[0075] Figure 13 This is a schematic diagram illustrating the generation of the three-phase inverter drive signal for the compressor-side drive converter in an embodiment of the present invention.

[0076] Figure 14 This is a structural block diagram of the control system for the silicon carbide device air conditioner compressor drive device according to an embodiment of the present invention;

[0077] Figure 15 The voltage and current waveforms on the grid side are shown.

[0078] Figure 16 This is a waveform diagram of the DC bus voltage.

[0079] Figure 17 This is a waveform diagram of the PMSM speed of the air conditioner compressor.

[0080] Figure 18 The diagram shows the PMSM torque waveform of the air conditioner compressor.

[0081] Figure 19 This is a waveform diagram of the three-phase current of the PMSM in an air conditioner compressor.

[0082] In the diagram, 1 is the acquisition module, 2 is the stationary coordinate transformation module, 3 is the voltage phase-locked loop module, 4 is the rotating coordinate transformation module, 5 is the linear signal generation module, 6 is the grid-side modulation signal generation module, 7 is the setting module, and 8 is the drive signal generation module. Detailed Implementation

[0083] The present invention will now be described in detail with reference to the accompanying drawings through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0084] Figure 1 The main topology circuit of the silicon carbide device air conditioner compressor drive unit shown includes a grid-side drive converter and a compressor-side drive converter. In the grid-side drive converter, U... a U b U c Q is the voltage of the three-phase power grid. xa1 To Q xa6 For phase a, SiCMOSFET power switching devices, D xa1 To D xa4 For the SiC Schottky diode, C3 and C4 are floating capacitors, L xa1 and L xa4 For stray inductance, L xa2 and L xa3 L is the separating inductor for phase a. xa5 For filtering inductors. In the compressor-side drive converter, C1 and C2 are DC bus capacitors, Q... ya1 To Q ya6 For phase a, SiC MOSFET power switching devices, D ya1 To D ya4 For the SiC Schottky diode, C5 and C6 are floating capacitors, L ya1 and L ya4 For stray inductance, L ya2 and L ya3 The inductor is the separator for phase a, and PMSM is the permanent magnet synchronous motor for the air conditioner compressor. It should be noted that the three-phase (a, b, c) topology is completely identical in both the grid-side drive converter and the air conditioner compressor-side drive converter. Figure 1 Only the topology circuit structure of phase a is given; the topology circuit structures of phases b and c are the same as those of phase a.

[0085] See also Figure 1 In a grid-side driven converter, taking phase a as an example, the connection method of the main circuit is explained. The three-phase grid voltage U... a U b U c Connected to point O2, the voltage U of phase a of the power grid a After filtering inductor L xa5 With the separating inductor L xa2 and the separating inductor L xa3 One side is connected to point X a5 Separating inductor L xa2 The other end is connected to the SiC MOSFET power switch Q. xa3 The source and SiC Schottky diode D xa4 The cathode is connected at point X. a3 Separating inductor L xa3 The other end is connected to the SiC MOSFET power switch Q. xa4 The drain and SiC Schottky diode D xa3 The anode is connected to point X. a2 SiC Schottky diode D xa3 Cathode, SiC MOSFET power switching device Q xa3 The drain of the capacitor, one end of the floating capacitor C3, and the stray inductance L xa1 One end and SiC MOSFET power switch Q xa1 The source is connected to point X. a1 SiC Schottky diode D xa4 The anode of the SiC MOSFET power switch device Q xa4 The source, one end of the floating capacitor C4, and the stray inductor L xa4 One end and SiC MOSFET power switch Q xa2 The drain is connected to point X. a6 The other ends of the floating capacitors C3 and C4 are connected to the SiC MOSFET power switch Q. xa6 The source is connected to point X. a4 SiCMOSFET power switching device Q xa6 The drain and SiC MOSFET power switching device Q xa5 The source and terminal of the SiC MOSFET power switch Q are connected. xa5 The drain of the SiC Schottky diode D xa1 The anode and SiC Schottky diode D xa2 The cathode is connected to point O1, and point O1 is connected to the compressor-side drive converter. SiC Schottky diode D xa1 Cathode and stray inductance L xa1One end is connected to the SiC Schottky diode D. xa2 anode and stray inductance L xa4 One end is connected; SiC MOSFET power switch Q xa1 The drain of the MOSFET is connected to point P, which is connected to the compressor-side drive converter. The SiC MOSFET power switch Q... xa2 The source of the circuit is connected to point N, which is connected to the compressor-side drive converter. The connection methods of the b-phase and c-phase main circuits are the same as those of the a-phase, and will not be described again here.

[0086] See also Figure 1 In the compressor-side drive converter, taking phase a as an example, the connection method of the main circuit is explained. One end of the DC bus capacitor C1 and the SiC MOSFET power switch Q... ya1 The drain of the SiC MOSFET power switch Q is connected to point P. ya1 Source, stray inductance L ya1 One end of the floating capacitor C5, and the SiC MOSFET power switch Q. ya3 The drain and SiC Schottky diode D ya3 The cathode is connected at point Y. a1 Stray inductance L ya1 The other end is connected to the SiC Schottky diode D. ya1 The cathodes are connected, and the SiC Schottky diode D is connected. ya1 The anode of the SiC MOSFET power switch device Q ya5 The source and SiC Schottky diode D ya2 The cathode is connected to point O1, and O1 is connected to the grid-side drive converter module. SiC MOSFET power switching device Q ya5 The drain and SiC MOSFET power switching device Q ya6 The drain of the SiC MOSFET power switch is connected to the phase of the circuit. ya6 The source, the other end of the floating capacitor C5, and one end of the floating capacitor C6 are connected to point Y. a4 The other end of the floating capacitor C6, and the stray inductance L ya4 One end of the SiC Schottky diode D ya2 The anode of the SiC MOSFET power switch device Q ya4 The source of the SiC MOSFET power switch Q ya2 The drain is connected to point Y. a6 Stray inductance L ya4 The other end and the SiC Schottky diode D ya2 The anode is connected to the SiC MOSFET power switch Q. ya2The source of the MOSFET and one end of the DC bus capacitor C2 are connected to point N, which is connected to the grid-side drive converter. The other ends of the DC bus capacitor C2 and the other ends of the DC bus capacitor C1 are connected to point O1, which is also connected to the grid-side drive converter. SiC MOSFET power switching device Q ya3 The source of the SiC Schottky diode D ya2 Cathode and separating inductor L ya2 One end is connected to point Y a3 SiC Schottky diode D ya3 The anode of the SiC MOSFET power switch device Q ya4 Drain and separating inductor L ya3 One end is connected to point Y a2 Separating inductor L ya2 , separating inductor L ya3 The other end is connected to the input interface of the permanent magnet synchronous motor (PMSM) of the air conditioner compressor at point Y. a5 The connection methods for phase b and phase c of the main circuit are the same as those for phase a, and will not be repeated here.

[0087] The aforementioned silicon carbide (SiC) air conditioner compressor drive unit utilizes SiC MOSFET power switching devices and SiC Schottky diodes in both the grid-side drive converter and the compressor-side converter. SiC MOSFET power switching devices offer fast switching speeds and low switching losses, while SiC Schottky diodes exhibit near-zero reverse recovery loss current. Together, these technologies significantly reduce losses in both the grid-side and compressor-side drive converters, thereby improving air conditioner efficiency. Furthermore, the separation of SiC MOSFET power switching devices through separating inductors minimizes mutual interference, greatly reducing the risk of shoot-through short circuits, enhancing the overall reliability of the air conditioner, and preventing unexpected shutdowns that could cause inconvenience or even economic losses for users.

[0088] Regarding the aforementioned silicon carbide device air conditioner compressor drive device, this invention provides a control method and system for the silicon carbide device air conditioner compressor drive device. Through precise control of multi-stage coordinate transformation and differentiated drive design of multi-carrier signals, it adapts to the high-speed switching characteristics of silicon carbide MOSFETs and other devices. At the same time, it takes into account the coordinated control of grid-side rectification and compressor-side inverter. It not only fully utilizes the low-loss and high-temperature resistance performance advantages of silicon carbide devices, but also completely solves the reliability problems caused by high-speed switching such as overvoltage, overshoot, and shoot-through short circuit from the control level. It has high control precision and can improve the efficiency, reliability and adaptability of air conditioner compressor drive device.

[0089] The control method and system for the air conditioner compressor drive device of the silicon carbide device of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0090] See Figure 2The first aspect of this invention provides a control method for a silicon carbide device air conditioner compressor drive device, the specific steps of which are as follows:

[0091] S1. Static Coordinate Transformation Step: Transform the three-phase grid voltage and current into grid voltage and current in a two-phase static coordinate system. This two-phase static coordinate transformation simplifies subsequent signal processing, removes the effects of three-phase imbalance, and improves the stability and anti-interference capability of the rectifier.

[0092] Specifically, in some embodiments, see [link to relevant documentation]. Figure 3 The method for transforming three-phase grid voltage into grid voltage in a two-phase stationary coordinate system is as follows:

[0093] Phase a grid voltage U a Apply phase b grid voltage U b Multiply by the first set coefficient and add the c-phase grid voltage U c Multiply by the first set coefficient, then multiply by the second set coefficient to obtain the grid voltage U. α ;

[0094] phase b grid voltage U b Multiply by the third set coefficient and add the c-phase grid voltage U c After multiplying by the third set factor, multiply by the second set factor to obtain the grid voltage U. β .

[0095] Specifically, in some embodiments, see [link to relevant documentation]. Figure 4 The method for transforming three-phase grid current into grid current in a two-phase stationary coordinate system is as follows:

[0096] Phase a grid current I a Add phase b grid current I b Multiply by the first set coefficient and add the c-phase grid current I c Multiply by the first set coefficient, then multiply by the second set coefficient to obtain the grid current I. α ;

[0097] b-phase grid current I b Multiply by the third set coefficient and add the c-phase grid current I c After multiplying by the third set factor, multiply by the second set factor to obtain the grid current I. β .

[0098] Specifically, the first setting coefficient is set to, but is not limited to, -0.5; the second setting coefficient is set to, but is not limited to, 2 / 3; and the third setting coefficient is set to, but is not limited to, 0.866. It should be noted that the first, second, and third setting coefficients can be set according to actual needs.

[0099] S2. Phase-locked processing is performed on the grid voltage in the two-phase stationary coordinate system to obtain the grid voltage angle signal. By performing phase-locked processing on the grid voltage in the two-phase stationary coordinate system, the grid voltage phase angle can be accurately extracted to ensure the accuracy of grid synchronization control.

[0100] Specifically, in some embodiments, see [link to relevant documentation]. Figure 5 The method for obtaining the grid voltage angle signal by performing phase-locked processing on the grid voltage in a two-phase stationary coordinate system is as follows:

[0101] Grid voltage U α The square of the grid voltage U β The first intermediate value is obtained by adding the squares together and then taking the square root.

[0102] Grid voltage U α Divide by the first intermediate value of the grid voltage angle signal sinθ, and the grid voltage U β Divide by the first intermediate value of the grid voltage angle signal cosθ, where θ is the grid voltage angle.

[0103] S3. Rotating Coordinate Transformation Steps: Based on the grid voltage phase angle, the three-phase grid voltage and current are transformed into grid voltage and current in a two-phase rotating coordinate system. Converting the three-phase grid voltage and current to the rotating coordinate system achieves decoupling control, improves energy transmission efficiency, reduces harmonic effects, and improves power quality.

[0104] Specifically, in some embodiments, see [link to relevant documentation]. Figure 6 The method for transforming the grid voltage in a two-phase stationary coordinate system into the grid voltage in a two-phase rotating coordinate system based on the voltage angle signal is as follows:

[0105] Grid voltage U α Multiply by cosθ and grid voltage U β Multiply by sinθ and add them together to obtain the d-axis grid voltage U in the two-phase rotating coordinate system. d ;

[0106] Grid voltage U α Multiply by sinθ, multiply by the fourth set coefficient, and then multiply by the grid voltage U. β Multiply by cosθ and add them together to obtain the q-axis grid voltage U in the two-phase rotating coordinate system. q .

[0107] Specifically, in some embodiments, see [link to relevant documentation]. Figure 7 The method for transforming the grid current in a two-phase stationary coordinate system into the grid current in a two-phase rotating coordinate system based on the voltage angle signal is as follows:

[0108] Grid current I α Multiply by cosθ and grid current I βMultiply by sinθ and add them together to obtain the d-axis grid current I in the two-phase rotating coordinate system. d ;

[0109] Grid current I α Multiply by sinθ, multiply by the fourth set coefficient, and multiply by the grid current I. β Multiplying by cosθ and adding them together, we obtain the q-axis grid current I in the two-phase rotating coordinate system. q .

[0110] Specifically, the fourth setting coefficient is set to, but is not limited to, -1. It should be noted that the fourth setting coefficient can be set according to actual needs.

[0111] S4. Linear signal generation steps: Generate a two-phase linear signal by PI control based on the actual DC bus voltage, grid voltage and grid current in the two-phase rotating coordinate system.

[0112] Specifically, in some embodiments, see further details. Figure 8 The method for generating a two-phase linear signal is as follows:

[0113] Set the desired DC bus voltage U dc ' The desired DC bus voltage U dc ' Reduce actual DC bus voltage U dc The difference is used to obtain the first intermediate value through PI control. The negative value of the first intermediate value is then subtracted from the d-axis grid current I. d The error value is processed by PI control to obtain a second intermediate value, which is then compared with the d-axis grid voltage U. d Adding them together yields the linear signal x of the d-axis. d ;

[0114] Set the desired grid current I along the q-axis q ' The desired grid current I along the q-axis q ' Reduce q-axis grid current I q The difference is used to obtain a third intermediate value through PI control. This third intermediate value is then compared with the q-axis grid voltage U. q Adding them together yields the q-axis linear signal x. q .

[0115] Specifically, the desired DC bus voltage U is set. dc ' The size is 600, and the desired grid current I on the q-axis is set. q ' The magnitude is 0. It should be noted that the expected DC bus voltage U... dc ' and the expected grid current I along the q-axis q 'The size can be set according to the actual situation.

[0116] Using the deviation between the actual DC bus voltage and the rated setpoint as the input of the PI control outer loop, it is directly related to the power input regulation logic of the grid-side rectifier. When the compressor load changes suddenly or the grid voltage fluctuates, causing the bus voltage to deviate from the rated value, the PI control can quickly output the appropriate regulation command and incorporate two-phase linear signals through real-time proportional adjustment and integral accumulation to eliminate the error. This achieves steady-state maintenance of the DC bus voltage without static error, avoiding the breakdown of silicon carbide devices due to excessively high bus voltage and the distortion of the inverter output on the compressor side due to excessively low bus voltage. This ensures the safe operation of SiC MOSFETs / SiC Schottky diodes and provides stable DC support for the adjustable frequency / voltage AC output of the compressor-side converter, thereby improving the operational reliability of the drive unit from the power supply head. Using the grid voltage and current in a two-phase rotating coordinate system as the input to the PI control inner loop, and leveraging the characteristic of converting AC quantities to DC quantities in the dq coordinate system, the PI control can achieve independent decoupling regulation of active and reactive components. By precisely setting the q-axis reactive current setpoint to 0, the PI control can quickly suppress grid-side reactive power losses, ensuring that the grid side outputs only active power, achieving unity power factor rectification. This precise regulation, combined with the low switching and low conduction losses of silicon carbide devices, significantly reduces grid-side harmonic and reactive power losses, allowing the energy efficiency advantages of silicon carbide devices to be fully utilized, further improving the overall energy conversion efficiency of the drive unit and reducing the overall operating energy consumption of the air conditioning unit.

[0117] Specifically, in some embodiments, the PI control employs a transfer function of K. PI =K P +K I A PI regulator of / s, where K P K is the proportionality coefficient. I Here, is the integral coefficient, and s is a complex variable in the frequency domain.

[0118] S5. Grid-side modulation signal generation steps: Based on the grid voltage angle signal and the actual DC bus voltage, the two-phase linear signal is transformed into three-phase stationary coordinates to obtain the three-phase modulation signal of the grid-side drive converter.

[0119] Using the grid voltage angle signal as the coordinate transformation reference and the actual DC bus voltage as the operating condition adaptation basis, the two-phase linear signal of the dq axis is inversely transformed into the three-phase modulation signal of the grid-side drive converter in the three-phase stationary coordinate system. This achieves the accurate conversion of the control signal from the rotating coordinate system to the actual engineering application coordinate system, making the control command of PI control highly compatible with the drive requirements of the grid-side silicon carbide converter. This ensures the accuracy, synchronization and operating condition adaptability of the modulation signal, and guarantees the reliable operation of the silicon carbide device from the signal generation level, giving full play to its performance advantages. At the same time, it connects the control links before and after to achieve efficient closed-loop control of grid-side rectification.

[0120] Specifically, in some embodiments, see [link to relevant documentation]. Figure 9 The method for obtaining the three-phase modulation signal of the grid-side drive converter by performing three-phase stationary coordinate transformation is as follows:

[0121] The linear signal x of the d-axis d Multiply by the fifth set coefficient and then divide by the actual DC bus voltage U dc Obtain the linear signal x d ' The q-axis linear signal x q Multiply by the fifth set coefficient and then divide by the actual DC bus voltage U dc Obtain the linear signal x q ' ;

[0122] linear signal x d ' Multiply by cosθ and subtract the linear signal x q ' Multiplying by sinθ yields the a-phase modulation signal x of the grid-side drive converter. a ;

[0123] Multiply sinθ by the third set coefficient, add cosθ by the first set coefficient, and then multiply by the linear signal x. d ' The first signal x1 is obtained. Then, sinθ is multiplied by a first set coefficient, cosθ is multiplied by a third set coefficient, and finally multiplied by the linear signal x. q ' The second signal x2 is obtained, and the first signal x1 is added to the second signal x2 to obtain the b-phase modulation signal x of the grid-side drive converter. b ;

[0124] Multiply cosθ by the first set coefficient, subtract sinθ by the third set coefficient, and then multiply by the linear signal x. d ' The third signal x3 is obtained. Sinθ is multiplied by the sixth set coefficient, then cosθ is multiplied by the third set coefficient, and finally multiplied by the linear signal x. q ' The fourth signal x4 is obtained; the third signal x3 is added to the fourth signal x4 to obtain the c-phase modulation signal x of the grid-side drive converter. c .

[0125] Specifically, the fifth setting coefficient is set to, but is not limited to, 2, and the sixth setting coefficient is set to, but is not limited to, 0.5. It should be noted that the fifth and sixth setting coefficients can be set according to actual needs.

[0126] S6. Setting steps: Set four isosceles triangular carrier signals with the same frequency but different amplitude ranges as carrier signals, and set the three-phase modulation signal for driving the compressor-side converter.

[0127] Specifically, in some embodiments, the first carrier signal is an isosceles triangular carrier signal with an amplitude range of 0.5 to 1 and a frequency of 10 kHz; the second carrier signal is an isosceles triangular carrier signal with an amplitude range of 0 to 0.5 and a frequency of 10 kHz; the third carrier signal is an isosceles triangular carrier signal with an amplitude range of -0.5 to 0 and a frequency of 10 kHz; and the fourth carrier signal is an isosceles triangular carrier signal with an amplitude range of -1 to -0.5 and a frequency of 10 kHz. It should be noted that the amplitude range and frequency of the carrier signals can be set according to actual conditions.

[0128] S7. Drive signal generation steps: Generate the i-phase rectifier drive signal of the grid-side drive converter based on the i-phase modulation signal and four carrier signals, i=a,b,c; Generate the i-phase inverter drive signal of the compressor-side drive converter based on the i-phase modulation signal and four carrier signals.

[0129] The four isosceles triangular carriers are designed with the same frequency but different amplitudes. By setting the amplitude range differently, the switching on / off rate of silicon carbide devices can be precisely controlled when matched with the modulation signal. This effectively suppresses the high voltage change rate (dv / dt) and high current change rate (di / dt) caused by parasitic capacitance and inductance in the circuit, eliminating overvoltage spikes and current overshoot at the drive signal level. At the same time, the logic matching of the differentiated carriers can strictly avoid the shoot-through short circuit problem of the inverter bridge arm on the grid side and compressor side, completely solving the core reliability pain point of silicon carbide devices in air conditioning drive units, significantly reducing the device failure rate, and extending the service life of the inverter and air conditioning unit.

[0130] The four carrier signals are shared by the grid-side and compressor-side converters. The corresponding rectifier / inverter drive signals are generated only by precisely matching the different modulation signals on both sides. This ensures the consistency of the carrier frequency of the two converters, realizes the coordinated linkage of the switching timing of the silicon carbide devices on both sides, and enables the grid-side power input and compressor-side power output to form a dynamic balance. This avoids problems such as DC bus voltage fluctuations and sudden changes in compressor speed caused by asynchronous operation of the two converters, and improves the overall operation coordination and stability of the drive unit.

[0131] Specifically, in some embodiments, see [link to relevant documentation]. Figure 10 The method for generating the i-phase rectifier drive signal for the grid-side drive converter is as follows:

[0132] Determine the i-phase modulation signal x of the grid-side drive converter iIf the value is greater than or equal to 0, then the first layer of superimposed carrier signal x is obtained. i1 The first carrier signal is carrier1, and the second superimposed carrier is x. i2 If the second carrier signal is carrier2, then the first layered carrier signal x is obtained. i1 The third carrier signal is carrier3, and the second layer of superimposed carrier signal is x. i2 The fourth carrier signal is carrier4;

[0133] The i-phase modulation signal x of the grid-side drive converter i After passing through the SIGN function, multiply by -0.5, and then add the i-phase modulation signal x of the grid-side drive converter. i Obtain the modulated signal x i ' ;

[0134] Determine the i-phase modulation signal x of the grid-side drive converter i Is it greater than or equal to the first layer carrier signal x? i1 If yes, the drive signal PWMXi1 is high; otherwise, the drive signal PWMXi1 is low.

[0135] Determine the i-phase modulation signal x of the grid-side drive converter i Is it less than or equal to the second-layer superimposed carrier signal x? i2 If yes, the drive signal PWMXi2 is high; otherwise, the drive signal PWMXi2 is low.

[0136] Determine the i-phase modulation signal x of the grid-side drive converter i If the value is greater than or equal to 0, then drive signal PWMXi3 is at a high level and drive signal PWMXi4 is at a low level; otherwise, drive signal PWMXi3 is at a low level and drive signal PWMXi4 is at a high level.

[0137] Determine the modulated signal x i ' If the value is greater than or equal to 0, then drive signals PWMXi5 and PWMXi6 are the inverted signals of drive signal PWMXi1; otherwise, drive signals PWMXi5 and PWMXi6 are the inverted signals of drive signal PWMXi2.

[0138] Specifically, see Figure 11 The method for generating the a-phase rectifier drive signal for the grid-side drive converter is as follows:

[0139] Determine the a-phase modulation signal x of the grid-side drive converter a If the value is greater than or equal to 0, then the first layer of superimposed carrier signal x is obtained. a1The first carrier signal is carrier1, and the second superimposed carrier is x. a2 If the second carrier signal is carrier2, then the first layered carrier signal x is obtained. a1 The third carrier signal is carrier3, and the second layer of superimposed carrier signal is x. a2 The fourth carrier signal is carrier4;

[0140] The modulation signal x of phase a of the grid-side drive converter a After passing through the SIGN function, multiply by -0.5, and then add the a-phase modulation signal x of the grid-side drive converter. a Obtain the modulated signal x a ' ;

[0141] Determine the a-phase modulation signal x of the grid-side drive converter a Is it greater than or equal to the first layer carrier signal x? a1 If yes, the drive signal PWMXa1 is high; otherwise, the drive signal PWMXa1 is low.

[0142] Determine the a-phase modulation signal x of the grid-side drive converter a Is it less than or equal to the second-layer superimposed carrier signal x? a2 If yes, the drive signal PWMXa2 is high; otherwise, the drive signal PWMXa2 is low.

[0143] Determine the a-phase modulation signal x of the grid-side drive converter a If the value is greater than or equal to 0, then drive signal PWMXa3 is high and drive signal PWMXa4 is low; otherwise, drive signal PWMXa3 is low and drive signal PWMXa4 is high.

[0144] Determine the modulated signal x a ' If the value is greater than or equal to 0, then drive signals PWMXa5 and PWMXa6 are the inverted signals of drive signal PWMXa1; otherwise, drive signals PWMXa5 and PWMXa6 are the inverted signals of drive signal PWMXa2.

[0145] Specifically, see [link to relevant documentation] Figure 11 The method for generating the b-phase rectifier drive signal for the grid-side drive converter is as follows:

[0146] Determine the b-phase modulation signal x of the grid-side drive converter b If the value is greater than or equal to 0, then the first layer of superimposed carrier signal x is obtained. b1 The first carrier signal is carrier1, and the second superimposed carrier is x.b2 If the second carrier signal is carrier2, then the first layered carrier signal x is obtained. b1 The third carrier signal is carrier3, and the second layer of superimposed carrier signal is x. b2 The fourth carrier signal is carrier4;

[0147] The b-phase modulation signal x of the grid-side drive converter b After passing through the SIGN function, multiply by -0.5, and then add the b-phase modulation signal x of the grid-side drive converter. b Obtain the modulated signal x b ' ;

[0148] Determine the b-phase modulation signal x of the grid-side drive converter b Is it greater than or equal to the first layer carrier signal x? b1 If yes, the drive signal PWMXb1 is high; otherwise, the drive signal PWMXb1 is low.

[0149] Determine the b-phase modulation signal x of the grid-side drive converter b Is it less than or equal to the second-layer superimposed carrier signal x? b2 If yes, the drive signal PWMXb2 is high; otherwise, the drive signal PWMXb2 is low.

[0150] Determine the b-phase modulation signal x of the grid-side drive converter b If the value is greater than or equal to 0, then drive signal PWMXb3 is at a high level and drive signal PWMXb4 is at a low level; otherwise, drive signal PWMXb3 is at a low level and drive signal PWMXb4 is at a high level.

[0151] Determine the modulated signal x b ' If the value is greater than or equal to 0, then drive signals PWMXb5 and PWMXb6 are the inverted signals of drive signal PWMXb1; otherwise, drive signals PWMXb5 and PWMXb6 are the inverted signals of drive signal PWMXb2.

[0152] Specifically, see [link to relevant documentation] Figure 11 The method for generating the c-phase rectifier drive signal for the grid-side drive converter is as follows:

[0153] Determine the c-phase modulation signal x of the grid-side drive converter c If the value is greater than or equal to 0, then the first layer of superimposed carrier signal x is obtained. c1 The first carrier signal is carrier1, and the second superimposed carrier is x. c2If the second carrier signal is carrier2, then the first layered carrier signal x is obtained. c1 The third carrier signal is carrier3, and the second layer of superimposed carrier signal is x. c2 The fourth carrier signal is carrier4;

[0154] The c-phase modulation signal x of the grid-side drive converter c After passing through the SIGN function, multiply by -0.5, and then add the c-phase modulation signal x of the grid-side drive converter. c Obtain the modulated signal x c ' ;

[0155] Determine the c-phase modulation signal x of the grid-side drive converter c Is it greater than or equal to the first layer carrier signal x? c1 If yes, the drive signal PWMXc1 is high; otherwise, the drive signal PWMXc1 is low.

[0156] Determine the c-phase modulation signal x of the grid-side drive converter c Is it less than or equal to the second-layer superimposed carrier signal x? c2 If yes, the drive signal PWMXc2 is high; otherwise, the drive signal PWMXc2 is low.

[0157] Determine the c-phase modulation signal x of the grid-side drive converter c If the value is greater than or equal to 0, then drive signal PWMXc3 is high and drive signal PWMXc4 is low; otherwise, drive signal PWMXc3 is low and drive signal PWMXc4 is high.

[0158] Determine the modulated signal x c ' If the value is greater than or equal to 0, then drive signals PWMXc5 and PWMXc6 are the inverted signals of drive signal PWMXc1; otherwise, drive signals PWMXc5 and PWMXc6 are the inverted signals of drive signal PWMXc2.

[0159] Specifically, in some embodiments, see Figure 12 The method for generating the i-phase inverter drive signal for the compressor-side drive converter is as follows:

[0160] Determine the i-phase modulation signal y of the compressor-side drive converter i If the value is greater than or equal to 0, then the third-layer superimposed carrier signal y is obtained. i1 The first carrier signal is carrier1, and the fourth superimposed carrier is y. i2If the second carrier signal is carrier2, then the third superimposed carrier signal y is obtained. i1 The third carrier signal is carrier3, and the fourth superimposed carrier signal is y. i2 The fourth carrier signal is carrier4;

[0161] The i-phase modulation signal y of the compressor-side drive converter i After passing through the SIGN function, multiply by -0.5, and then add the i-phase modulation signal y of the compressor-side drive converter. i Obtain the modulated signal y i ' ;

[0162] Determine the i-phase modulation signal y of the compressor-side drive converter i Is it greater than or equal to the third-layer superimposed carrier signal y? i1 If yes, the drive signal PWMYi1 is high; otherwise, the drive signal PWMYi1 is low.

[0163] Determine the i-phase modulation signal y of the compressor-side drive converter i Is it less than or equal to the fourth layer superimposed carrier signal y? i2 If yes, the drive signal PWMYi2 is high; otherwise, the drive signal PWMYi2 is low.

[0164] Determine the i-phase modulation signal y of the compressor-side drive converter i If the value is greater than or equal to 0, then drive signal PWMYi3 is high and drive signal PWMYi4 is low; otherwise, drive signal PWMYi3 is low and drive signal PWMYi4 is high.

[0165] Determine the modulated signal y i ' If the value is greater than or equal to 0, then the driving signals PWMYi5 and PWMYi6 are the inverted signals of the driving signal PWMYi1; otherwise, the driving signals PWMYi5 and PWMYi6 are the inverted signals of the driving signal PWMYi2.

[0166] Specifically, see Figure 13 The method for generating the a-phase inverter drive signal for the compressor-side drive converter is as follows:

[0167] Determine the a-phase modulation signal y of the compressor-side drive converter. a If the value is greater than or equal to 0, then the third-layer superimposed carrier signal y is obtained. a1 The first carrier signal is carrier1, and the fourth superimposed carrier is y. a2If the second carrier signal is carrier2, then the third superimposed carrier signal y is obtained. a1 The third carrier signal is carrier3, and the fourth superimposed carrier signal is y. a2 The fourth carrier signal is carrier4;

[0168] The a-phase modulation signal y of the compressor-side drive converter a After passing through the SIGN function, multiply by -0.5, and then add the a-phase modulation signal y of the compressor-side drive converter. a Obtain the modulated signal y a ' ;

[0169] Determine the a-phase modulation signal y of the compressor-side drive converter. a Is it greater than or equal to the third-layer superimposed carrier signal y? a1 If yes, the drive signal PWMYa1 is high; otherwise, the drive signal PWMYa1 is low.

[0170] Determine the a-phase modulation signal y of the compressor-side drive converter. a Is it less than or equal to the fourth layer superimposed carrier signal y? a2 If yes, the drive signal PWMYa2 is high; otherwise, the drive signal PWMYa2 is low.

[0171] Determine the a-phase modulation signal y of the compressor-side drive converter. a If the value is greater than or equal to 0, then drive signal PWMYa3 is high and drive signal PWMYa4 is low; otherwise, drive signal PWMYa3 is low and drive signal PWMYa4 is high.

[0172] Determine the modulated signal y a ' If the value is greater than or equal to 0, then drive signals PWMYa5 and PWMYa6 are the inverted signals of drive signal PWMYa1; otherwise, drive signals PWMYa5 and PWMYa6 are the inverted signals of drive signal PWMYa2.

[0173] Specifically, see [link to relevant documentation] Figure 13 The method for generating the b-phase inverter drive signal for the compressor-side drive converter is as follows:

[0174] Determine the b-phase modulation signal y of the compressor-side drive converter b If the value is greater than or equal to 0, then the third-layer superimposed carrier signal y is obtained. b1 The first carrier signal is carrier1, and the fourth superimposed carrier is y. b2If the second carrier signal is carrier2, then the third superimposed carrier signal y is obtained. b1 The third carrier signal is carrier3, and the fourth superimposed carrier signal is y. b2 The fourth carrier signal is carrier4;

[0175] The b-phase modulation signal y of the compressor-side drive converter b After passing through the SIGN function, multiply by -0.5, and then add the b-phase modulation signal y of the compressor-side drive converter. b Obtain the modulated signal y b ' ;

[0176] Determine the b-phase modulation signal y of the compressor-side drive converter b Is it greater than or equal to the third-layer superimposed carrier signal y? b1 If yes, the drive signal PWMYb1 is high; otherwise, the drive signal PWMYb1 is low.

[0177] Determine the b-phase modulation signal y of the compressor-side drive converter b Is it less than or equal to the fourth layer superimposed carrier signal y? b2 If yes, the drive signal PWMYb2 is high; otherwise, the drive signal PWMYb2 is low.

[0178] Determine the b-phase modulation signal y of the compressor-side drive converter b If the value is greater than or equal to 0, then drive signal PWMYb3 is high and drive signal PWMYb4 is low; otherwise, drive signal PWMYb3 is low and drive signal PWMYb4 is high.

[0179] Determine the modulated signal y b ' If the value is greater than or equal to 0, then drive signals PWMYb5 and PWMYb6 are the inverted signals of drive signal PWMYb1; otherwise, drive signals PWMYb5 and PWMYb6 are the inverted signals of drive signal PWMYb2.

[0180] Specifically, see [link to relevant documentation] Figure 13 The method for generating the c-phase inverter drive signal for the compressor-side drive converter is as follows:

[0181] Determine the c-phase modulation signal y of the compressor-side drive converter. c If the value is greater than or equal to 0, then the third-layer superimposed carrier signal y is obtained. c1 The first carrier signal is carrier1, and the fourth superimposed carrier is y. c2If the second carrier signal is carrier2, then the third superimposed carrier signal y is obtained. c1 The third carrier signal is carrier3, and the fourth superimposed carrier signal is y. c2 The fourth carrier signal is carrier4;

[0182] The c-phase modulation signal y of the compressor-side drive converter c After passing through the SIGN function, multiply by -0.5, and then add the c-phase modulation signal y of the compressor-side drive converter. c Obtain the modulated signal y c ' ;

[0183] Determine the c-phase modulation signal y of the compressor-side drive converter. c Is it greater than or equal to the third-layer superimposed carrier signal y? c1 If yes, the drive signal PWMYc1 is high; otherwise, the drive signal PWMYc1 is low.

[0184] Determine the c-phase modulation signal y of the compressor-side drive converter. c Is it less than or equal to the fourth layer superimposed carrier signal y? c2 If yes, the drive signal PWMYc2 is high; otherwise, the drive signal PWMYc2 is low.

[0185] Determine the c-phase modulation signal y of the compressor-side drive converter. c If the value is greater than or equal to 0, then drive signal PWMYc3 is at a high level and drive signal PWMYc4 is at a low level; otherwise, drive signal PWMYc3 is at a low level and drive signal PWMYc4 is at a high level.

[0186] Determine the modulated signal y c ' If the value is greater than or equal to 0, then drive signals PWMYc5 and PWMYc6 are the inverted signals of drive signal PWMYc1; otherwise, drive signals PWMYc5 and PWMYc6 are the inverted signals of drive signal PWMYc2.

[0187] exist Figures 10 to 13 During the drive signal generation process, a switch is used to determine and select the signal. The switch is divided into an input side and an output side. The input side has three signal input terminals: the middle one is a control signal input terminal, and the other two are selection signal input terminals. The output side has only one signal output terminal. The selection signal input terminal, which selects the target path based on the control signal, receives the input signal.

[0188] A second aspect of this invention provides a control system for a silicon carbide device air conditioner compressor drive device, used to implement the silicon carbide device air conditioner compressor drive device control method described in the first aspect of this invention. See also... Figure 14 The control system includes:

[0189] Module 1 is used to acquire three-phase grid voltage, three-phase grid current, and actual DC bus voltage.

[0190] The stationary coordinate transformation module 2 is used to transform the three-phase grid voltage and three-phase grid current into grid voltage and grid current in a two-phase stationary coordinate system.

[0191] Voltage phase-locked module 3 is used to perform phase-locked processing on the grid voltage in a two-phase stationary coordinate system to obtain the grid voltage angle signal;

[0192] Rotating coordinate transformation module 4 is used to transform the grid voltage and grid current in the two-phase stationary coordinate system into the grid voltage and grid current in the two-phase rotating coordinate system based on the voltage angle signal.

[0193] Linear signal generation module 5 is used to generate two-phase linear signals based on the actual DC bus voltage, grid voltage and grid current in the two-phase rotating coordinate system using PI control.

[0194] The grid-side modulation signal generation module 6 is used to perform a three-phase static coordinate transformation on the two-phase linear signal based on the grid voltage angle signal and the actual DC bus voltage to obtain the three-phase modulation signal for the grid-side drive converter.

[0195] Setting module 7 is used to set four isosceles triangular carrier signals with the same frequency but different amplitude ranges as carrier signals, and to set the three-phase modulation signal for driving the compressor-side converter.

[0196] The drive signal generation module 8 is used to generate the i-phase rectifier drive signal of the grid-side drive converter based on the i-phase modulation signal and four carrier signals of the grid-side drive converter, i=a,b,c; and to generate the i-phase inverter drive signal of the compressor-side drive converter based on the i-phase modulation signal and four carrier signals of the compressor-side drive converter.

[0197] To verify the effectiveness of the control method and system for the air conditioner compressor drive device of the silicon carbide device described above in this invention, a simulation model was built using SIMULINK for verification. Grid-side voltage U a U b and U c The phase difference is 120° Three sets of sinusoidal AC voltages are used, with the effective value of the phase voltage set to 220V and the frequency set to 50Hz. The DC bus capacitor and floating capacitors C1~C6 are set to 3.3mF, and the filter inductor L...xa5 Set to 1mH, stray inductance L xa1 L xa4 L ya1 and L ya4 Set to 3μH, with a separating inductor L xa2 L xa2 L ya2 and L ya2 Set to 1μH. Compressor-side converter three-phase modulation wave y a y b and y c The frequency is set to 50Hz. The air conditioner compressor PMSM is a three-phase permanent magnet synchronous motor. The parameters of the permanent magnet synchronous motor M are as follows: stator resistance is 2.875Ω, direct-axis inductance is 0.0085H, quadrature-axis inductance is 0.0085H, flux linkage is 0.42Wb, moment of inertia is 0.001kg·m², number of pole pairs is 4, and the motor speed is set to 750rpm. A step load of 10N·m is added at 0.16s of the simulation time. Specific parameters can be set according to actual conditions.

[0198] Figure 15 The voltage and current waveforms on the grid side are shown. Figure 16 The DC bus voltage waveform is shown. Figure 17 The PMSM speed waveform of the air conditioner compressor is given; Figure 18 The PMSM torque waveform diagram of the air conditioner compressor is given; Figure 19 The waveform diagram of the three-phase current of the air conditioner compressor PMSM is given.

[0199] Figure 15 The voltage and current waveforms on the grid side are shown, indicating that the three-phase voltage and current are in phase. After the system stabilizes, Fourier analysis of the three-phase currents reveals that the total harmonic distortion rates of the grid-side three-phase currents are 1.70%, 1.98%, and 2.08%, respectively, which are below the 5% limit specified in the grid connection standard. Figure 16 The DC bus voltage waveform is given. After the system stabilizes, the DC bus voltage can stabilize near the expected value of 600V. Parameters such as the overshoot and settling time of the DC bus voltage are related to... Figure 8 In linear signal generation, the proportional gain coefficient of the PI controller is related to the integral time constant, and the specific parameters can be set according to actual needs. Figure 17 The waveform diagram of the PMSM speed of the air conditioning compressor is given. When the system is stable, the PMSM speed of the air conditioning compressor is stable at around 750 rpm. Even if a step load of 10 N·m is added, the system can achieve speed adjustment in a short time and achieve long-term stable operation of the system. Figure 18The PMSM torque waveform of the air conditioning compressor is given. Once the system stabilizes, the torque can be stabilized. Even with a step load of 10 N·m, the system can achieve torque regulation in a short time. Figure 19 The waveforms of the three-phase current (PMSM) of the air conditioner compressor are presented. Fourier analysis of the three-phase current (PMSM) of the air conditioner compressor is performed, and the total harmonic distortion rates (THDs) of the three-phase current (PMSM) of the air conditioner compressor are 0.81%, 0.83%, and 0.83%, respectively. The simulation results demonstrate the feasibility of the silicon carbide air conditioner compressor drive device control method and system proposed in this invention.

[0200] The above embodiments are used to explain the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A control method for a silicon carbide device air conditioner compressor drive device, characterized in that, The specific steps are as follows: The static coordinate transformation steps are as follows: Transform the three-phase grid voltage and three-phase grid current into grid voltage and grid current in a two-phase static coordinate system; Voltage phase-locking steps: Phase-locking is performed on the grid voltage in the two-phase stationary coordinate system to obtain the grid voltage angle signal; Rotating coordinate transformation steps: Based on the voltage angle signal, transform the grid voltage and grid current in the two-phase stationary coordinate system into the grid voltage and grid current in the two-phase rotating coordinate system; Linear signal generation steps: Generate a two-phase linear signal by performing PI control based on the actual DC bus voltage, grid voltage and grid current in the two-phase rotating coordinate system; Grid-side modulation signal generation steps: Based on the grid voltage angle signal and the actual DC bus voltage, the two-phase linear signal is transformed into three-phase stationary coordinates to obtain the three-phase modulation signal for the grid-side drive converter; Setting steps: Set four isosceles triangular carrier signals with the same frequency but different amplitude ranges as carrier signals, and set the three-phase modulation signal for driving the compressor-side converter; Drive signal generation steps: Generate the i-phase rectifier drive signal of the grid-side drive converter based on the i-phase modulation signal and four carrier signals, i=a,b,c; Generate the i-phase inverter drive signal of the compressor-side drive converter based on the i-phase modulation signal and four carrier signals. The method for generating the i-phase rectifier drive signal for the grid-side drive converter is as follows: Judging whether the i-phase modulation signal x of the grid-side driving converter is greater than or equal to 0 i If yes, obtaining a first layered carrier signal x i1 The first carrier signal carrier1, the second layered carrier x i2 The second carrier signal carrier2, if no, obtaining the first layered carrier signal x i1 The third carrier signal carrier3, the second layered carrier signal x i2 The fourth carrier signal carrier4; The i-phase modulation signal x of the grid-side drive converter i After passing through the SIGN function, multiply by -0.5, and then add the i-phase modulation signal x of the grid-side drive converter. i Obtain the modulated signal x i ' ; Determine the i-phase modulation signal x of the grid-side drive converter i Is it greater than or equal to the first layer carrier signal x? i1 If yes, the drive signal PWMXi1 is high; otherwise, the drive signal PWMXi1 is low. Determine the i-phase modulation signal x of the grid-side drive converter i Is it less than or equal to the second-layer superimposed carrier signal x? i2 If yes, the drive signal PWMXi2 is high; otherwise, the drive signal PWMXi2 is low. Determine the i-phase modulation signal x of the grid-side drive converter i If the value is greater than or equal to 0, then drive signal PWMXi3 is at a high level and drive signal PWMXi4 is at a low level; otherwise, drive signal PWMXi3 is at a low level and drive signal PWMXi4 is at a high level. Determine the modulated signal x i ' If the value is greater than or equal to 0, then drive signals PWMXi5 and PWMXi6 are the inverted signals of drive signal PWMXi1; otherwise, drive signals PWMXi5 and PWMXi6 are the inverted signals of drive signal PWMXi2.

2. The control method for the silicon carbide device air conditioner compressor drive device as described in claim 1, characterized in that, In the aforementioned static coordinate transformation, the method for transforming the three-phase grid voltage into the grid voltage in a two-phase static coordinate system is as follows: Phase a grid voltage U a Apply phase b grid voltage U b Multiply by the first set coefficient and add the c-phase grid voltage U c Multiply by the first set coefficient, then multiply by the second set coefficient to obtain the grid voltage U. α ; phase b grid voltage U b Multiply by the third set coefficient and add the c-phase grid voltage U c After multiplying by the third set factor, multiply by the second set factor to obtain the grid voltage U. β ; The method for transforming three-phase grid current into grid current in a two-phase stationary coordinate system is as follows: Phase a grid current I a Add phase b grid current I b Multiply by the first set coefficient and add the c-phase grid current I c Multiply by the first set coefficient, then multiply by the second set coefficient to obtain the grid current I. α ; b-phase grid current I b Multiply by the third set coefficient and add the c-phase grid current I c After multiplying by the third set factor, multiply by the second set factor to obtain the grid current I. β .

3. The control method for the silicon carbide device air conditioner compressor drive device as described in claim 2, characterized in that, In the voltage phase-locking step, the method for obtaining the grid voltage angle signal by performing phase-locking processing on the grid voltage in the two-phase stationary coordinate system is as follows: Grid voltage U α The square of the grid voltage U β The first intermediate value is obtained by adding the squares together and then taking the square root. Grid voltage U α Divide by the first intermediate value of the grid voltage angle signal sinθ, and the grid voltage U β Divide by the first intermediate value of the grid voltage angle signal cosθ, where θ is the grid voltage angle.

4. The control method for the silicon carbide device air conditioner compressor drive device as described in claim 3, characterized in that, In the rotating coordinate transformation step, the method for transforming the grid voltage in the two-phase stationary coordinate system to the grid voltage in the two-phase rotating coordinate system based on the voltage angle signal is as follows: Grid voltage U α Multiply by cosθ and grid voltage U β Multiply by sinθ and add them together to obtain the d-axis grid voltage U in the two-phase rotating coordinate system. d ; Grid voltage U α Multiply by sinθ, multiply by the fourth set coefficient, and multiply by the grid voltage U. β Multiply by cosθ and add them together to obtain the q-axis grid voltage U in the two-phase rotating coordinate system. q ; The method for transforming grid current in a two-phase stationary coordinate system into grid current in a two-phase rotating coordinate system based on voltage angle signals is as follows: Grid current I α Multiply by cosθ and grid current I β Multiply by sinθ and add them together to obtain the d-axis grid current I in the two-phase rotating coordinate system. d ; Grid current I α Multiply by sinθ, multiply by the fourth set coefficient, and multiply by the grid current I. β Multiplying by cosθ and adding them together, we obtain the q-axis grid current I in the two-phase rotating coordinate system. q .

5. The control method for the silicon carbide device air conditioner compressor drive device as described in claim 4, characterized in that, In the linear signal generation step, the method for generating a two-phase linear signal is as follows: Set the desired DC bus voltage U dc ' The desired DC bus voltage U dc ' Reduce actual DC bus voltage U dc The difference is used to obtain the first intermediate value through PI control. The negative value of the first intermediate value is then subtracted from the d-axis grid current I. d The error value is processed by PI control to obtain a second intermediate value, which is then compared with the d-axis grid voltage U. d Adding them together yields the linear signal x of the d-axis. d ; Set the desired grid current I along the q-axis q ' The desired grid current I along the q-axis q ' Reduce q-axis grid current I q The difference is used to obtain a third intermediate value through PI control. This third intermediate value is then compared with the q-axis grid voltage U. q Adding them together yields the q-axis linear signal x. q .

6. The control method for the silicon carbide device air conditioner compressor drive device as described in claim 5, characterized in that, In the grid-side modulation signal generation step, the method for obtaining the three-phase modulation signal of the grid-side drive converter by performing three-phase stationary coordinate transformation is as follows: The linear signal x of the d-axis d Multiply by the fifth set coefficient and then divide by the actual DC bus voltage U dc Obtain the linear signal x d ' The q-axis linear signal x q Multiply by the fifth set coefficient and then divide by the actual DC bus voltage U dc Obtain the linear signal x q ' ; linear signal x d ' Multiply by cosθ and subtract the linear signal x q ' Multiplying by sinθ yields the a-phase modulation signal x of the grid-side drive converter. a ; Multiply sinθ by the third set coefficient, add cosθ by the first set coefficient, and then multiply by the linear signal x. d ' The first signal x1 is obtained. Then, sinθ is multiplied by a first set coefficient, cosθ is multiplied by a third set coefficient, and finally multiplied by the linear signal x. q ' The second signal x2 is obtained, and the first signal x1 is added to the second signal x2 to obtain the b-phase modulation signal x of the grid-side drive converter. b ; Multiply cosθ by the first set coefficient, subtract sinθ by the third set coefficient, and then multiply by the linear signal x. d ' The third signal x3 is obtained. Sinθ is multiplied by the sixth set coefficient, then cosθ is multiplied by the third set coefficient, and finally multiplied by the linear signal x. q ' The fourth signal x4 is obtained; the third signal x3 is added to the fourth signal x4 to obtain the c-phase modulation signal x of the grid-side drive converter. c .

7. The control method for the silicon carbide device air conditioner compressor drive device as described in claim 6, characterized in that, In the drive signal generation step, the method for generating the i-phase inverter drive signal for the compressor-side drive converter is as follows: Determine the i-phase modulation signal y of the compressor-side drive converter i If the value is greater than or equal to 0, then the third-layer superimposed carrier signal y is obtained. i1 The first carrier signal is carrier1, and the fourth superimposed carrier is y. i2 If the second carrier signal is carrier2, then the third superimposed carrier signal y is obtained. i1 The third carrier signal is carrier3, and the fourth superimposed carrier signal is y. i2 The fourth carrier signal is carrier4; The i-phase modulation signal y of the compressor-side drive converter i After passing through the SIGN function, multiply by -0.5, and then add the i-phase modulation signal y of the compressor-side drive converter. i Obtain the modulated signal y i ' ; Determine the i-phase modulation signal y of the compressor-side drive converter i Is it greater than or equal to the third-layer superimposed carrier signal y? i1 If yes, the drive signal PWMYi1 is high; otherwise, the drive signal PWMYi1 is low. Determine the i-phase modulation signal y of the compressor-side drive converter i Is it less than or equal to the fourth layer superimposed carrier signal y? i2 If yes, the drive signal PWMYi2 is high; otherwise, the drive signal PWMYi2 is low. Determine the i-phase modulation signal y of the compressor-side drive converter i If the value is greater than or equal to 0, then drive signal PWMYi3 is high and drive signal PWMYi4 is low; otherwise, drive signal PWMYi3 is low and drive signal PWMYi4 is high. Determine the modulated signal y i ' If the value is greater than or equal to 0, then the driving signals PWMYi5 and PWMYi6 are the inverted signals of the driving signal PWMYi1; otherwise, the driving signals PWMYi5 and PWMYi6 are the inverted signals of the driving signal PWMYi2.

8. A control system for a silicon carbide device air conditioner compressor drive device, used to implement the control method for the silicon carbide device air conditioner compressor drive device as described in any one of claims 1 to 7, characterized in that, include: The acquisition module is used to acquire three-phase grid voltage, three-phase grid current, and actual DC bus voltage. The stationary coordinate transformation module is used to transform three-phase grid voltage and three-phase grid current into grid voltage and grid current in a two-phase stationary coordinate system; The voltage phase-locked module is used to perform phase-locking processing on the grid voltage in a two-phase stationary coordinate system to obtain the grid voltage angle signal. The rotating coordinate transformation module is used to transform the grid voltage and grid current in a two-phase stationary coordinate system into the grid voltage and grid current in a two-phase rotating coordinate system based on the voltage angle signal. The linear signal generation module is used to generate a two-phase linear signal based on the actual DC bus voltage, the grid voltage and grid current in the two-phase rotating coordinate system using PI control. The grid-side modulation signal generation module is used to perform a three-phase static coordinate transformation on the two-phase linear signal based on the grid voltage angle signal and the actual DC bus voltage to obtain the three-phase modulation signal for the grid-side drive converter. The setting module is used to set four isosceles triangular carrier signals with the same frequency but different amplitude ranges as carrier signals, and to set the three-phase modulation signal for driving the compressor-side converter. The drive signal generation module is used to generate the i-phase rectifier drive signal of the grid-side drive converter based on the i-phase modulation signal and four carrier signals of the grid-side drive converter, i=a,b,c; and to generate the i-phase inverter drive signal of the compressor-side drive converter based on the i-phase modulation signal and four carrier signals of the compressor-side drive converter.

Images