Frequency converter control method, device and equipment, frequency converter and medium

Abstract

The invention relates to a frequency converter control method, device and equipment, a frequency converter and a medium, and the method comprises the steps: obtaining the temperature of a power switch device of the frequency converter, and determining a space vector pulse width modulation mode of the frequency converter according to the temperature of the power switch device; and then, on the basis of the space vector pulse width modulation mode, determining a carrier frequency and a space vector time sequence corresponding to the carrier frequency, and performing space vector pulse width modulation according to the space vector time sequence to obtain a three-phase modulated wave signal, thereby controlling a power switch device in the frequency converter through the three-phase modulated wave signal. The problem that the output power of the frequency converter is forcibly reduced or the device is damaged due to the fact that the temperature of the power switch device is too high in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a frequency converter control method, device, equipment, frequency converter and medium. Background Art

[0002] In the field of motor control, the control of the motor is usually achieved through the space vector pulse width modulation (SVPWM) control method, that is, in a carrier frequency cycle, the vector acts in a time-sharing manner to form a time sequence of a space vector in time. At present, the industry usually samples a higher carrier frequency for control, that is, outputs a three-phase modulation wave signal to the inverter according to a relatively high carrier frequency, so as to control the power switch device in the inverter through the three-phase modulation wave signal, and then control the output of the inverter to achieve the drive control of the motor, and in each carrier frequency cycle, adjust the time sequence of the space vector so that it works according to seven switching working states, so that there will be six switching switches in each carrier frequency cycle, and each switching action will cause the power switch device to generate heat and generate junction temperature. Under the condition of constant load, the higher the carrier frequency, the smaller the switching cycle, the more times the power switch device acts in the same time, and the greater the heat. If the external heat dissipation conditions are not good, the heat generated by the power switch device cannot be dissipated in time, resulting in excessively high junction temperature, and the inverter output power is forced to be reduced. In severe cases, the power switch device will be burned, causing the motor to fail and shut down. Summary of the invention

[0003] In view of this, the present application provides a frequency converter control method, device, equipment, frequency converter and medium to solve the problem in the existing related technology that the frequency converter output power is forced to be reduced or the device is damaged due to the excessive temperature of the power switching device.

[0004] In a first aspect, an embodiment of the present application provides a frequency converter control method, comprising:

[0005] Get the temperature of the power switch device of the inverter;

[0006] Determining a space vector pulse width modulation mode of the frequency converter according to the temperature of the power switch device;

[0007] Based on the space vector pulse width modulation method, determining a carrier frequency and a space vector timing corresponding to the carrier frequency;

[0008] Performing space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal;

[0009] The power switch device in the frequency converter is controlled by the three-phase modulation wave signal.

[0010] Optionally, determining the space vector pulse width modulation mode of the inverter according to the temperature of the power switch device includes: when the temperature of the power switch device does not reach a preset protection temperature, determining the first debugging control mode set by default for the inverter as the space vector pulse width modulation mode;

[0011] Among them, the determining of the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode includes: when the space vector pulse width modulation mode is the first debugging control mode, obtaining the pulse width modulation frequency set by default for the inverter; determining the pulse width modulation frequency as the carrier frequency; and performing timing calculation based on the carrier frequency in combination with the switch state information corresponding to the first debugging control mode to obtain the space vector timing.

[0012] Optionally, determining the space vector pulse width modulation mode of the inverter according to the temperature of the power switch device includes: when the temperature of the power switch device reaches a preset protection temperature, determining the preset second debugging control mode corresponding to the protection temperature as the space vector pulse width modulation mode;

[0013] The determining of the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation method includes:

[0014] When the space vector pulse width modulation mode is the second debugging control mode, frequency reduction processing is performed based on the pulse width modulation frequency of the frequency converter to obtain the carrier frequency;

[0015] Based on the carrier frequency, timing calculation is performed in combination with the preset switch state information corresponding to the second debugging control mode to obtain the space vector timing.

[0016] Optionally, performing timing calculation based on the carrier frequency and in combination with switch state information corresponding to the second debugging control mode to obtain the space vector timing includes:

[0017] Determining a pulse width modulation period according to the carrier frequency;

[0018] Determine the number of switch switching times according to the switch state information;

[0019] According to the pulse width modulation period, the voltage space vector time corresponding to each switch state is obtained by calculating in combination with the switch switching times and the DC bus voltage of the inverter;

[0020] The space vector timing is generated based on the voltage space vector times corresponding to the respective switch states.

[0021] Optionally, the switch switching times are less than a default switch switching times, and the default switch switching times are the switch switching times corresponding to the first debugging control mode.

[0022] Optionally, the performing timing calculation based on the carrier frequency and in combination with switch state information corresponding to the first debugging control mode to obtain the space vector timing includes:

[0023] Determining a pulse width modulation period according to the carrier frequency;

[0024] Determine a default number of switching times according to the switch state information;

[0025] According to the pulse width modulation period, the default switching times and the DC bus voltage of the inverter are combined to calculate to obtain the voltage space vector time corresponding to each switching state;

[0026] The space vector timing sequence is generated based on the voltage space vector times corresponding to the respective switch states.

[0027] Optionally, obtaining the temperature of a power switch device of the inverter includes:

[0028] Performing temperature collection on the power switch device in the frequency converter to obtain temperature collection information;

[0029] The temperature of the power switch device is determined according to the temperature acquisition information.

[0030] In a second aspect, an embodiment of the present application provides a frequency converter control device, comprising:

[0031] A temperature acquisition module is used to obtain the temperature of the power switch device of the inverter;

[0032] A modulation mode determination module, used to determine the space vector pulse width modulation mode of the inverter according to the temperature of the power switch device;

[0033] A vector timing determination module, used to determine a carrier frequency and a space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode;

[0034] A pulse width modulation module, used for performing space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal;

[0035] The control module is used to control the power switch device in the inverter through the three-phase modulation wave signal.

[0036] In a third aspect, an embodiment of the present application provides an electronic device, comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; the memory is used to store computer programs; the processor is used to implement the steps of the inverter control method as described in any one of the first aspects of the present application when executing the program stored in the memory.

[0037] In a fourth aspect, an embodiment of the present application provides a computer storage medium storing computer executable instructions, wherein the computer executable instructions are used to execute the steps of the inverter control method as described in any one of the first aspect of the present application.

[0038] In a fifth aspect, an embodiment of the present application provides a frequency converter, including: a frequency converter control device as described in the second aspect.

[0039] In a sixth aspect, an embodiment of the present application provides an electrical device, comprising: a permanent magnet synchronous motor and a frequency converter connected to the permanent magnet synchronous motor, the frequency converter comprising the frequency converter control device as described in the second aspect.

[0040] The inverter control method, device, equipment, inverter and medium provided in the embodiments of the present application obtain the temperature of the power switching device of the inverter, and determine the space vector pulse width modulation mode of the inverter according to the temperature of the power switching device, so as to determine the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode, so that space vector pulse width modulation can be performed according to the space vector timing to obtain a three-phase modulation wave signal, and then the power switching device in the inverter is controlled by the three-phase modulation wave signal, so as to effectively reduce the heat generation of the power switching device while ensuring the motor control efficiency and control stability, thereby solving the problem of the inverter output power being forced to be reduced or the device being damaged due to the excessive temperature of the power switching device in the existing related technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0043] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0044] Figure 1 A schematic diagram of a step flow of a frequency converter control method provided in an embodiment of the present application;

[0045] Figure 2 A schematic diagram of a frequency converter controlling a motor as an example of the present application;

[0046] Figure 3 A timing diagram of a frequency converter provided in an example of the present application that needs to switch power switch devices 7 times in one switching cycle;

[0047] Figure 4 A timing diagram of a frequency converter provided in an example of this application that needs to switch the power switch device 5 times in one switching cycle;

[0048] Figure 5 A timing diagram of the example provided in this application in which the number of switching times of the power switch device in the same cycle is changed from 6 to 2;

[0049] Figure 6 A vector action sector diagram provided for the example of this application;

[0050] Figure 7 A structural block diagram of a frequency converter control device provided in an embodiment of the present application;

[0051] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0052] Fig. 9 A schematic diagram of a computer storage medium provided in an embodiment of the present application;

[0053] Fig.10 A structural block diagram of a frequency converter provided in an embodiment of the present application;

[0054] Fig.11 A schematic diagram of the structure of an electrical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0056] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0057] In order to prevent the motor power from being reduced and the power switching device in the inverter from being damaged by overheating, the embodiments of the present application provide a method, device, equipment, inverter and medium for controlling an inverter, by determining a space vector pulse width modulation mode according to the temperature of the power switching device of the inverter, determining a carrier frequency and a space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode, and then performing space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal, and controlling the power switching device in the inverter through the three-phase modulated wave signal, so as to reduce the number of actions of the power switching device as much as possible within the same switching cycle while ensuring the motor control efficiency and control stability, thereby effectively reducing the heat generated by the power switching device, and solving the problem in the existing related technology that the output power of the inverter is forced to be reduced or the device is damaged due to excessive temperature of the power switching device.

[0058] It should be noted that the carrier frequency can be used to determine the number of times the power switch device in the inverter is turned on and off, so the carrier frequency can also be called the switching frequency, which is not limited in the embodiments of the present application.

[0059] Figure 1 A schematic flow chart of a frequency converter control method provided in an embodiment of the present application. Figure 1 As shown, the inverter control method provided in the embodiment of the present application may include the following steps:

[0060] Step 110, obtaining the temperature of the power switch device of the inverter;

[0061] The power switch device temperature of the frequency converter is the detected temperature corresponding to the power switch device in the frequency converter. For example, the temperature of the power switch device in the frequency converter can be detected by a temperature sensor, and the detected temperature information is used as the power switch device temperature.

[0062] Step 120, determining a space vector pulse width modulation mode of the inverter according to the temperature of the power switch device;

[0063] Among them, the space vector pulse width modulation mode refers to the debugging mode of space vector pulse width modulation, which can be specifically divided into a continuous debugging mode and a discontinuous debugging mode. Specifically, in order to solve the problems such as the forced reduction of the inverter output power or the damage and functional failure of the device due to the excessive temperature of the power switch device, after obtaining the temperature of the power switch device, the embodiment of the present application can compare the temperature of the power switch device with the preset protection temperature, so that when the temperature of the power switch device reaches the protection temperature, the discontinuous debugging mode is determined as the space vector pulse width modulation mode of the inverter, so as to reduce the number of actions of the power switch device as much as possible within the same carrier cycle TPWM, thereby effectively reducing the heating of the power switch device and reducing the temperature of the power switch device; and when the temperature of the power switch device does not reach the preset protection temperature, the continuous debugging mode set by default of the inverter is determined as the space vector pulse width modulation mode, so as to perform space vector pulse width modulation according to the continuous debugging mode set by default, so as to ensure the motor control efficiency and control stability of the inverter.

[0064] As an example of the present application, when an insulated-gate bipolar transistor (IGBT) is used as a power switch device in a frequency converter, Figure 2 As shown, the inverter can form a three-phase bridge arm through 6 IGBTs, which is connected to the permanent magnet synchronous motor M that it needs to drive and control, and the continuous debugging mode can be set to the space vector pulse width modulation mode set by default for the inverter. When it is detected that the IGBT temperature reaches the protection temperature, the debugging mode of SVPWM can be changed to determine the non-continuous debugging mode as the space vector pulse width modulation mode of the inverter, thereby reducing the number of switching of the IGBT as much as possible within the same carrier period TPWM and reducing the temperature rise of the IGBT switching device; and when the temperature does not reach the protection temperature, the debugging mode of SVPWM can be unchanged to maintain the space vector pulse width modulation mode set by default for the inverter, that is, the continuous debugging mode is determined as the space vector pulse width modulation mode of the inverter, so that the space vector pulse width modulation can be performed in the continuous debugging mode later.

[0065] Step 130, determining a carrier frequency and a space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode;

[0066] Among them, the carrier frequency refers to the corresponding space vector timing, which refers to the space vector timing required for space vector pulse width modulation based on the carrier frequency. It can be specifically used to generate a three-phase modulation wave signal of the inverter, and the three-phase modulation wave signal can be used to control the switching state of the power switching device in the inverter.

[0067] Specifically, in this step, the carrier frequency currently required to be adopted by the inverter can be determined according to the space vector pulse width modulation method. For example, when the space vector pulse width modulation method is a continuous debugging method, the carrier frequency F1 set by default by the inverter can be determined as the carrier frequency currently required to be adopted by the inverter; and when the space vector pulse width modulation method is a discontinuous debugging method, the low carrier frequency lower than the default carrier frequency F1 set by the inverter can be determined as the carrier frequency currently required to be adopted by the inverter by frequency reduction. For example, the low carrier frequency with a frequency value of F1 / 2 can be determined as the carrier frequency currently required to be adopted by the inverter, so that the carrier frequency currently required to be adopted by the inverter is cut from the original default setting of F1 to F1 / 2, which is reduced by half.

[0068] After determining the carrier frequency currently required to be used by the frequency converter, the space vector timing required for space vector pulse width modulation can be determined according to the carrier frequency currently required to be used by the frequency converter as the space vector timing corresponding to the carrier frequency, so that space vector pulse width modulation can be performed subsequently according to the space vector timing, that is, executing step 140.

[0069] Step 140, performing space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal;

[0070] Specifically, after determining the space vector timing corresponding to the carrier frequency, the embodiment of the present application can perform space vector pulse width modulation according to the space vector timing in combination with the DC bus voltage of the inverter to obtain a three-phase modulated wave signal, so that the power switch device in the inverter can be controlled by the three-phase modulated wave signal to achieve output control of the inverter. The three-phase modulated wave signal includes a modulated wave signal of three-phase alternating current, and specifically includes: modulated wave signals of three-phase alternating currents A, B, and C.

[0071] Step 150: Control the power switch device in the inverter through the three-phase modulation wave signal.

[0072] Specifically, after obtaining the three-phase modulated wave signal, the embodiment of the present application can output the three-phase modulated wave signal to the power switching device in the inverter, so as to control the switching state of the power switching device through the three-phase modulated wave signal, and then control the output power of the inverter to obtain the control result of the inverter.

[0073] It can be seen that the inverter control method provided by the implementation of the present application obtains the temperature of the power switching device of the inverter, and determines the space vector pulse width modulation mode of the inverter according to the temperature of the power switching device, so as to determine the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode, and then performs space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal, so as to control the power switching device in the inverter through the three-phase modulated wave signal, so as to reduce the number of actions of the power switching device as much as possible within the same switching cycle while ensuring the motor control efficiency and control stability, and can effectively reduce the heat generation of the power switching device, thereby solving the problem of the inverter output power being forced to be reduced or the device being damaged due to the excessive temperature of the power switching device in the existing related technology.

[0074] In some optional embodiments of the present application, the temperature of the power switch device of the inverter can be obtained by temperature acquisition, so as to determine the space vector pulse width modulation mode of the inverter according to the temperature of the power switch device. Optionally, the embodiment of the present application obtains the temperature of the power switch device of the inverter, which can specifically include the following sub-steps:

[0075] Sub-step S11, collecting temperature of the power switch device in the inverter to obtain temperature collection information;

[0076] Sub-step S12, determining the temperature of the power switch device according to the temperature acquisition information.

[0077] Specifically, the embodiment of the present application collects the temperature of the power switch device in the inverter, thereby collecting temperature information, and can use the collected temperature information as temperature collection information to determine the temperature of the power switch device according to the temperature collection information. The temperature collection information may include the temperature information collected by collecting the temperature of the power switch device in the inverter. For example, when an IGBT is used as the power switch device in the inverter, the temperature of the IGBT can be collected at all times through a temperature sensor, and the IGBT temperature collected within a fixed period of time can be used as temperature collection information, so that the average value of the IGBT temperature information collected within this period of time is determined as the temperature of the power switch device of the inverter.

[0078] It can be seen that the embodiment of the present application can obtain the temperature information collected within a period of time to calculate the average value of the temperature information collected within this period of time, and determine the average value as the temperature of the power switching device in the current time period, so that the space vector pulse width modulation mode of the inverter can be determined subsequently according to the temperature of the power switching device.

[0079] Optionally, after obtaining the temperature of the power switching device of the inverter, the embodiment of the present application can determine the space vector pulse width modulation mode of the inverter by judging whether the temperature of the power switching device reaches a preset protection temperature, so as to minimize the switching times of the power switching device within the same switching cycle time while ensuring the motor control efficiency and control stability, thereby reducing the heat generated by the power switching device inside the inverter and improving the efficiency of the inverter.

[0080] In an optional implementation of the present application, the space vector pulse width modulation mode of the inverter is determined based on the temperature of the power switching device, which may specifically include: judging whether the temperature of the power switching device reaches a preset protection temperature; if the temperature of the power switching device does not reach the protection temperature, determining the first debugging control mode set by default for the inverter as the space vector pulse width modulation mode; if the temperature of the power switching device reaches the protection temperature, determining the second debugging control mode preset corresponding to the protection temperature as the space vector pulse width modulation mode.

[0081] Specifically, after obtaining the temperature of the power switching device of the inverter, the embodiment of the present application determines whether the temperature of the power switching device reaches a preset protection temperature, so that when the temperature of the power switching device reaches the preset protection temperature, the preset second debugging control mode corresponding to the protection temperature is determined as a space vector pulse width modulation mode; and when the temperature of the power switching device does not reach the preset protection temperature, the first debugging control mode set by default of the inverter is determined as a space vector pulse width modulation mode, so that the carrier frequency and the space vector timing corresponding to the carrier frequency can be determined based on the space vector pulse width modulation mode, and the switching times of the power switching device can be reduced as much as possible within the same cycle time, which can effectively reduce the heat generation of the power switching device inside the intelligent power module of the inverter and improve the efficiency of the inverter.

[0082] For example, when IGBT is used as the power switching device in the inverter, in order to solve the problems such as the inverter output power is forced to be reduced due to the excessive temperature of the IGBT device or the device damage, functional failure, insufficient unit capacity or unit non-operation caused by the excessive temperature of the IGBT device, the continuous debugging mode can be set in advance as the first debugging control mode set by default for the inverter, and the discontinuous debugging mode can be used as the second debugging control mode preset corresponding to the protection temperature. By detecting the temperature of the IGBT switching device, and using the detected temperature of the IGBT switching device as the acquired power switching device temperature of the inverter, it is determined whether the space vector pulse width modulation debugging mode needs to be changed by judging whether the temperature of the power switching device reaches the preset protection temperature, so that when the temperature of the power switching device reaches the preset protection temperature, the debugging mode of the space vector pulse width modulation can be changed. When the temperature of the power switch device does not reach the preset protection temperature, the SVPWM debugging mode can be maintained to determine the first debugging control mode set by default for the inverter as the space vector pulse width modulation mode, that is, to determine the continuous debugging mode as the space vector pulse width modulation mode, so that the carrier frequency used for the space vector pulse width modulation of the inverter and the space vector timing corresponding to the carrier frequency can be determined according to the continuous debugging mode.

[0083] It can be seen that after obtaining the temperature of the power switching device of the inverter, the embodiment of the present application can determine whether it is necessary to change the debugging mode of the space vector pulse width modulation by judging whether the temperature of the power switching device reaches the preset protection temperature, so that when the temperature of the power switching device reaches the preset protection temperature, the debugging mode of the space vector pulse width modulation is changed, thereby reducing the switching times of the power switching device within the same cycle time, reducing the heat generated by the power switching device inside the intelligent power module of the inverter, and improving the efficiency of the inverter.

[0084] In some optional implementations of the present application, in order to reduce the temperature rise of the power switch device, after the temperature of the power switch device reaches the preset protection temperature, in addition to changing the debugging mode of the space vector pulse width modulation, the embodiment of the present application can also reduce the carrier frequency by frequency reduction processing, so as to use a lower carrier frequency for space vector pulse width modulation, thereby further reducing the number of switching times of the power switch device in the same cycle time. Specifically, the embodiment of the present application determines the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode, which can specifically include: when the space vector pulse width modulation mode is the second debugging control mode, frequency reduction processing is performed based on the pulse width modulation frequency of the inverter to obtain the carrier frequency; based on the carrier frequency, timing calculation is performed in combination with the preset switch state information corresponding to the second debugging control mode to obtain the space vector timing.

[0085] Among them, the preset switch state information corresponding to the second debugging control mode can be used to determine the number of switch switching times corresponding to the second debugging control mode, and the number of switch switching times corresponding to the second debugging control mode refers to the number of times the power switch in the inverter is switched within the same carrier cycle when the second debugging control mode is used for space vector pulse width modulation. Optionally, the embodiment of the present application performs timing calculation based on the carrier frequency and the switch state information corresponding to the second debugging control mode to obtain the space vector timing, which may specifically include: determining the pulse width modulation period according to the carrier frequency; determining the number of switch switching times according to the switch state information; calculating according to the pulse width modulation period, combining the number of switch switching times and the DC bus voltage of the inverter to obtain the voltage space vector time corresponding to each switch state; generating the space vector timing based on the voltage space vector time corresponding to each switch state.

[0086] In the embodiment of the present application, the number of switch switching times corresponding to the second debugging control mode is less than the default number of switching times, and the default number of switching times is the number of switching times corresponding to the first debugging control mode. The number of switching times corresponding to the first debugging control mode refers to the number of times the power switch in the inverter is switched within the same carrier cycle when the first debugging control mode is used for space vector pulse width modulation.

[0087] For example, when the first debugging control mode is a continuous debugging mode and the second debugging control mode is a discontinuous debugging mode, based on the continuous debugging mode, it can be determined that the default switching times of the inverter in one switching cycle Tpwm are 7 times, such as Figure 3 As shown, based on the preset switch state information corresponding to the second debugging control mode, it is determined that the number of switch switching times corresponding to the second debugging control mode is 5 times, such as Figure 4As shown. Among them, A, B, and C waveforms are the switch tube states of the three-phase bridge arm of the inverter bridge, respectively. The high level means that the power switch tube on the upper side of the corresponding bridge arm is turned on, and the low level means that the power switch tube on the lower side of the corresponding bridge arm is turned on.

[0088] Optionally, the present embodiment described in which the carrier frequency and the space vector timing corresponding to the carrier frequency are determined based on the space vector pulse width modulation mode, and may include: when the space vector pulse width modulation mode is the first debugging control mode, obtaining the pulse width modulation frequency set by default for the inverter; determining the pulse width modulation frequency as the carrier frequency; and performing timing calculation based on the carrier frequency in combination with the switch state information corresponding to the first debugging control mode to obtain the space vector timing.

[0089] In some optional embodiments of the present application, a timing calculation is performed based on the carrier frequency in combination with the switch state information corresponding to the first debugging control mode to obtain the space vector timing, which may specifically include: determining a pulse width modulation period according to the carrier frequency, so as to determine a default number of switches according to the switch state information, and then calculating according to the pulse width modulation period in combination with the default number of switches and the DC bus voltage of the inverter to obtain the voltage space vector time corresponding to each switch state, so that the space vector timing can be generated based on the voltage space vector time corresponding to each switch state.

[0090] In a specific implementation, the inverter control method provided in the embodiment of the present application can be used as an efficient control method based on a permanent magnet synchronous motor. By detecting the temperature of a power switch device in the inverter, when the temperature of the power switch device reaches a preset protection temperature, the protection temperature is determined to correspond to a preset second debugging control mode as a space vector pulse width modulation mode, and based on the second debugging control mode, the pulse width modulation frequency of the inverter is down-converted, such as switching the PWM carrier frequency from the original carrier frequency F1 to F1 / 2 to reduce the carrier frequency by half, and the preset switch state signal corresponding to the second debugging control mode can be determined. Information is obtained by switching the power switch device in the inverter from seven switch working states to five switch working states to change the adjustment space vector timing, thereby effectively reducing the number of switching of the power switch device in the same switching cycle TPWM. For example, since the seven switch working states will have 6 switching times in each carrier frequency cycle, and the five switch working states will have 4 switching times in each carrier frequency cycle, plus the halving of the PWM carrier frequency, the number of switching of the power switch device in the same cycle will be reduced from the original 6 times to 2 times, that is, to 1 / 3 of the original, such as Figure 5As shown, while maintaining the output power of the inverter, the heat generated by the power switch device can be effectively reduced, thereby improving the efficiency of the inverter. The implementation method is simple and does not require additional external heat sink costs.

[0091] In an optional embodiment of the present application, according to the pulse width modulation period, combined with the switch switching number and the DC bus voltage of the inverter, a calculation is performed to obtain the voltage space vector time corresponding to each switching state, which may specifically include: determining the sector where the voltage space vector is located; calculating according to the pulse width modulation period corresponding to the voltage space vector and the carrier frequency to obtain two basic vector action times and zero vector action times of the sector, so that the two basic vector action times and the zero vector action time can be used to determine the voltage space vector time corresponding to each switching state of the inverter.

[0092] For example, taking IGBT as the power switching device in the inverter, the motor control takes into account the optimal harmonics and noise. The first debugging control method can be used by default to perform space vector pulse width modulation of the inverter, and the seven switching working states with high carrier frequency F1 are used based on the first debugging control method to control the IGBT in the inverter circuit; when the inverter is used in a harsh environment with poor heat dissipation, the heat generated by the power switching device IGBT in the inverter circuit cannot be dissipated, and the temperature continues to rise. In order to maintain the power of the unit and the reliability of components and avoid damage to the device, when the temperature of the IGBT reaches the preset temperature protection value, the SVPWM control method can be changed, and the protection temperature corresponding to the preset second debugging control method is determined as a space vector pulse width modulation method, and the five switching working states with low carrier frequency F1 / 2 are used for control based on the second debugging control method. By reducing the number of switches in one cycle of the IGBT, the heat generation of the device is reduced, thereby achieving the purpose of reducing temperature rise.

[0093] Among them, the specific calculation and implementation process of the space vector time series is as follows:

[0094] First, we can determine the sector where the control vector is located, such as setting U1 = -V β , From a geometric point of view, three lines are used to divide a regular hexagon into six parts. Figure 6As shown; when U1>0, the level value of the modulation wave signal of phase A is a high level voltage value of 1, otherwise the level value of the modulation wave signal of phase A is a low level voltage value of 0, that is, when 0>U1, the level value of the modulation wave signal of phase A is a low level voltage value of 0; when U2>0, the level value of the modulation wave signal of phase B is a high level voltage of 1, otherwise, the level value of the modulation wave signal of phase B is a low level voltage value of 0, that is, when 0>U2, the level value of the modulation wave signal of phase B is a low level voltage value of 0; when U3>0, the level value of the modulation wave signal of phase C is a high level voltage of 1, otherwise, the level value of the modulation wave signal of phase C is a low level voltage value of 0, that is, when 0>U3, the level value of the modulation wave signal of phase C is a low level voltage value of 0; therefore, the sector number S in the geometric figure can be determined according to the sector number calculation formula S=4A+2B+C, as shown Figure 6 As shown; wherein, U1 is a vector voltage used to represent the modulation wave signal of phase A; U2 is a vector voltage used to represent the modulation wave signal of phase B; U3 is a vector voltage used to represent the modulation wave signal of phase C.

[0095] Secondly, based on the DC bus voltage U dc , calculate the action time of the two basic vectors in each sector, where the reference vector V ref Take the first sector as an example for calculation. The counterclockwise basic vector action time in the sector is T1, and the other basic vector action time is T2. If the PWM period is the switching period T pwm , the absolute values ​​of the six basic voltage vectors are According to the area equivalence principle, the calculation formula can be obtained: Among them, U6 is a basic vector used to divide the first sector; U4 is another basic vector used to divide the first sector.

[0096] Based on the calculation formula: By combining the voltage decomposition formula of the α-axis and the voltage decomposition formula of the β-axis, the basic vector action time T1 can be obtained as Right now Another basic vector action time T2 is Right now Among them, the voltage decomposition formula of the α axis and the voltage decomposition formula of the β axis are as follows:

[0097]

[0098] Based on the two basic vector action times T1 and T2, the vector action time can be calculated according to the formula: T0 = T PWM -T1-T2, determine the zero vector action time T0, and similarly, when V ref When calculating the results in other sectors, for example, in the calculation results, let: The action time of two basic vectors in six sectors is shown in Table 1:

[0099] Sector S 1 2 3 4 5 6 T1 X -Y Z -Z Y -X T2 -Z X Y -Y -X Z

[0100] Table 1

[0101] After calculating the two basic vector action times in the six sectors, the two basic vector action times in the six sectors can be used to determine the voltage space vector time corresponding to each switching state in the inverter, so as to generate a space vector timing sequence based on the voltage space vector time corresponding to each switching state, and then space vector pulse width modulation can be performed according to the space vector timing sequence to output a three-phase modulated wave signal to control the IGBT in the inverter and realize efficient control based on the permanent magnet synchronous motor.

[0102] Specifically, during the control process, the IGBT temperature is collected at all times, and it is determined whether the collected IGBT temperature reaches the preset protection temperature. When the IGBT temperature reaches the preset protection temperature, that is, when the IGBT temperature reaches the protection value, the SVPWM control scheme is changed to arrange the action order of each vector, that is, the action order of the switching signal.

[0103] Specifically, when the IGBT temperature is lower than the protection value, that is, when the IGBT temperature does not reach the preset protection temperature, the 7 switching working states of the high carrier frequency F1 are used for control, with the goal of reducing the number of switches. The distribution principle of the basic vector action sequence is selected as follows: at each switching state conversion, only the switching state of one phase is changed, and the two zero vectors U0 (000) and U7 (111) are evenly distributed in time to make the generated PWM symmetrical, thereby effectively reducing the harmonic components of PWM, such as Figure 3 As shown, within a carrier switching period Tpwm, the IGBT switch needs to switch 6 times.

[0104] When the IGBT temperature is higher than the protection value, in order to maintain the unit power and component reliability and avoid damage to the device, considering the control stability, the carrier frequency is switched to half of the high carrier frequency for modulation, that is, by reducing the frequency, the carrier frequency is switched to the low carrier frequency F1 / 2, and 5 switching working states are used for control to further reduce the number of switches and reduce the loss of switching devices. Taking sector 6 as an example, only two adjacent vectors U4 (100) and U5 (101) are used in conjunction with a zero vector U7 (111) for modulation within the switching period Tpwm of the same carrier. By arranging different switching orders in different intervals, a symmetrical output waveform can be obtained, such as Figure 5As shown, in this way, within a carrier switching period Tpwm, the IGBT switch only needs to be switched twice, that is, the switching times of the IGBT switching device can be reduced within the same cycle time, making the IGBT switching times become 1 / 3 of the original, which can effectively reduce the temperature rise of the IGBT device while maintaining the output power of the inverter without reducing, thereby improving the efficiency of the inverter. The implementation method is simple and does not require additional external heat sink costs.

[0105] It should be noted that, for the purpose of simple description, the method embodiments are expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present application are not limited to the described order of actions, because according to the embodiments of the present application, certain steps may be performed in other orders or simultaneously.

[0106] like Figure 7 As shown, an embodiment of the present application also provides a frequency converter control device, which may specifically include the following modules:

[0107] A temperature acquisition module 710 is used to acquire the temperature of a power switch device of the inverter;

[0108] A modulation mode determination module 720, configured to determine a space vector pulse width modulation mode of the inverter according to the temperature of the power switch device;

[0109] A vector timing determination module 730, configured to determine a carrier frequency and a space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode;

[0110] A pulse width modulation module 740 is used to perform space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal;

[0111] The control module 750 is used to control the power switch device in the inverter through the three-phase modulation wave signal.

[0112] Optionally, the modulation mode determination module 720 includes the following submodules:

[0113] A judgment submodule, used to judge whether the temperature of the power switch device reaches a preset protection temperature;

[0114] A first debugging control determination submodule, configured to determine the first debugging control mode set by default for the inverter as a space vector pulse width modulation mode when the temperature of the power switch device does not reach the protection temperature;

[0115] The second debugging control determination submodule is used to determine the preset second debugging control mode corresponding to the protection temperature as a space vector pulse width modulation mode when the temperature of the power switch device reaches the protection temperature.

[0116] Optionally, the vector timing determination module 730 includes the following submodules:

[0117] A frequency reduction processing submodule, used for performing frequency reduction processing based on the pulse width modulation frequency of the frequency converter to obtain the carrier frequency when the space vector pulse width modulation mode is the second debugging control mode;

[0118] The timing calculation submodule is used to perform timing calculation based on the carrier frequency and the preset switch state information corresponding to the second debugging control mode to obtain the space vector timing.

[0119] Optionally, the timing calculation submodule is specifically used to: determine a pulse width modulation period according to the carrier frequency; determine the number of switch switching times according to the switch state information; calculate according to the pulse width modulation period, in combination with the number of switch switching times and the DC bus voltage of the inverter to obtain the voltage space vector time corresponding to each switch state; based on the voltage space vector time corresponding to each switch state, generate the space vector timing.

[0120] Optionally, the switch switching times are less than a default switch switching times, and the default switch switching times are the switch switching times corresponding to the first debugging control mode.

[0121] Optionally, the vector timing determination module 730 includes the following submodules:

[0122] An acquisition submodule, used for acquiring a pulse width modulation frequency set by default for the frequency converter when the space vector pulse width modulation mode is the first debugging control mode;

[0123] A determination submodule, configured to determine the pulse width modulation frequency as the carrier frequency;

[0124] The timing calculation submodule is used to perform timing calculation based on the carrier frequency and in combination with the switch state information corresponding to the first debugging control mode to obtain the space vector timing.

[0125] Optionally, the temperature acquisition module 710 includes the following submodules:

[0126] A temperature acquisition submodule is used to acquire the temperature of the power switch device in the inverter to obtain temperature acquisition information;

[0127] The temperature determination submodule is used to determine the temperature of the power switch device according to the temperature acquisition information.

[0128] In a specific implementation, the inverter control device can be integrated into an electronic device as an inverter control device, so that the electronic device can obtain the temperature of the power switch device of the inverter to determine the space vector pulse width modulation method according to the temperature of the power switch device of the inverter, and determine the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation method, so as to perform space vector pulse width modulation according to the space vector timing to obtain a three-phase modulation wave signal, so that the power switch device in the inverter can be controlled by the three-phase modulation wave signal to realize permanent magnet synchronous motor control, so as to reduce the number of actions of the power switch device as much as possible within the same switching cycle while ensuring the motor control efficiency and control stability, thereby effectively reducing the heat generated by the power switch device, and solving the problem of forced reduction of inverter output power or damage of the device due to excessive temperature of the power switch device in the existing related technology.

[0129] like Figure 8 As shown, an embodiment of the present application further provides an electronic device, comprising: a processor 111, a communication interface 112, a memory 113 and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114, and the memory 113 is used to store computer programs; the processor 111 is used to implement the steps of the inverter control method provided by any of the aforementioned method embodiments when executing the computer program stored in the memory 113.

[0130] like Fig. 9 As shown, the embodiment of the present application further provides a computer storage medium 900 storing computer executable instructions 910, wherein the computer executable instructions 910 are used to execute the steps of the inverter control method provided in any of the aforementioned method embodiments.

[0131] In a specific implementation, the above-mentioned inverter control device can be integrated in the inverter, so that the inverter can determine the space vector pulse width modulation method according to the temperature of the power switching device of the inverter, and determine the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation method, so as to perform space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal, so that the power switching device can be controlled by the three-phase modulated wave signal, so as to reduce the number of actions of the power switching device as much as possible within the same switching cycle while ensuring the motor control efficiency and control stability, thereby effectively reducing the heat generated by the power switching device, thereby solving the problem of the inverter output power being forced to be reduced or the device being damaged due to the excessive temperature of the power switching device in the existing related technology.

[0132] like Fig.10As shown, an embodiment of the present application also provides an inverter 101, which includes an inverter control device 102; the inverter control device 102 includes the inverter control device in the above embodiment, so that the inverter can realize permanent magnet synchronous motor control by executing the steps of the inverter control method provided in any of the above method embodiments, so as to reduce the number of actions of the power switching device as much as possible within the same switching cycle while ensuring the motor control efficiency and control stability, thereby effectively reducing the heat generated by the power switching device.

[0133] like Fig.11 As shown, an embodiment of the present application also provides an electrical device 1101, which includes: a permanent magnet synchronous motor 1102 and a frequency converter 102 connected to the permanent magnet synchronous motor 1102, and the frequency converter 102 includes the frequency converter control device in the above embodiment, so that the electrical device can realize permanent magnet synchronous motor control through the frequency converter by executing the frequency converter control method provided by any of the above method embodiments, so as to reduce the number of actions of the power switching device as much as possible within the same switching cycle while ensuring the motor control efficiency and control stability, thereby effectively reducing the heat generated by the power switching device.

[0134] The above described apparatus, device, frequency converter, and medium embodiments are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0135] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the relevant technology can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0136] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0137] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A frequency converter control method, characterized in that: include: Obtain the temperature of the power switch device of the inverter; Determining a space vector pulse width modulation mode of the frequency converter according to the temperature of the power switch device; Based on the space vector pulse width modulation method, determining a carrier frequency and a space vector timing corresponding to the carrier frequency; Performing space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal; The power switch device in the frequency converter is controlled by the three-phase modulation wave signal.

2. The inverter control method according to claim 1, characterized in that: Determining the space vector pulse width modulation mode of the inverter according to the temperature of the power switch device includes: when the temperature of the power switch device does not reach a preset protection temperature, determining the first debugging control mode set by default for the inverter as the space vector pulse width modulation mode; The method of determining a carrier frequency and a space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation method includes: when the space vector pulse width modulation method is a first debugging control method, obtaining a pulse width modulation frequency set by default for the frequency converter; determining the pulse width modulation frequency as the carrier frequency; and performing timing calculation based on the carrier frequency in combination with switch state information corresponding to the first debugging control method to obtain the space vector timing.

3. The inverter control method according to claim 2, characterized in that: Determining the space vector pulse width modulation mode of the inverter according to the temperature of the power switch device includes: when the temperature of the power switch device reaches a preset protection temperature, determining the preset second debugging control mode corresponding to the protection temperature as the space vector pulse width modulation mode; The method of determining the carrier frequency and the space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation method includes: when the space vector pulse width modulation method is the second debugging control method, performing frequency reduction processing based on the pulse width modulation frequency of the frequency converter to obtain the carrier frequency; performing timing calculation based on the carrier frequency in combination with preset switch state information corresponding to the second debugging control method to obtain the space vector timing.

4. The inverter control method according to claim 2, characterized in that: Based on the carrier frequency, timing calculation is performed in combination with the switch state information corresponding to the second debugging control mode to obtain the space vector timing, including: Determining a pulse width modulation period according to the carrier frequency; Determine the number of switch switching times according to the switch state information; According to the pulse width modulation period, the voltage space vector time corresponding to each switch state is obtained by calculating in combination with the switch switching times and the DC bus voltage of the inverter; The space vector timing is generated based on the voltage space vector times corresponding to the respective switch states.

5. The frequency converter control method according to claim 4, characterized in that: The switch switching times are less than a default switch switching times, and the default switch switching times are the switch switching times corresponding to the first debugging control mode.

6. The inverter control method according to claim 2, characterized in that: The performing timing calculation based on the carrier frequency and in combination with the switch state information corresponding to the first debugging control mode to obtain the space vector timing includes: Determining a pulse width modulation period according to the carrier frequency; Determine a default number of switching times according to the switch state information; According to the pulse width modulation period, the default switching times and the DC bus voltage of the inverter are combined to calculate to obtain the voltage space vector time corresponding to each switching state; The space vector timing is generated based on the voltage space vector times corresponding to the respective switch states.

7. The frequency converter control method according to any one of claims 1 to 6, characterized in that: The step of obtaining the temperature of a power switch device of the frequency converter comprises: Performing temperature collection on the power switch device in the frequency converter to obtain temperature collection information; The temperature of the power switch device is determined according to the temperature acquisition information.

8. A frequency converter control device, characterized in that: include: A temperature acquisition module is used to obtain the temperature of the power switch device of the inverter; A modulation mode determination module, used to determine the space vector pulse width modulation mode of the inverter according to the temperature of the power switch device; A vector timing determination module, used to determine a carrier frequency and a space vector timing corresponding to the carrier frequency based on the space vector pulse width modulation mode; A pulse width modulation module, used for performing space vector pulse width modulation according to the space vector timing to obtain a three-phase modulated wave signal; The control module is used to control the power switch device in the inverter through the three-phase modulation wave signal.

9. An electronic device, characterized in that: include: A processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory, used to store computer programs; The processor is used to implement the steps of the inverter control method as described in any one of claims 1 to 7 when executing the program stored in the memory.

10. A computer storage medium storing computer executable instructions, characterized in that: The computer executable instructions are used to execute the steps of the inverter control method as described in any one of claims 1-7.

11. A frequency converter, characterized in that: include: The frequency converter control device as claimed in claim 8.

12. An electrical equipment, characterized in that: include: A permanent magnet synchronous motor and a frequency converter connected to the permanent magnet synchronous motor, wherein the frequency converter comprises the frequency converter control device as claimed in claim 8.

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