Control method of motor driver and electronic equipment

Abstract

The invention relates to a control method of a motor driver and electronic equipment. The method comprises the following steps: improving a grid-side power factor of a motor driver based on a harmonic suppression strategy followed by bus disturbance, and obtaining a DC bus voltage currently detected in a circuit; performing low-pass filtering processing on the DC bus voltage to obtain a first voltage; performing analog filtering processing on the DC bus voltage to obtain a second voltage; according to the first voltage, the second voltage and a voltage obtained after the DC bus voltage is suppressed, a grid-side power factor of the motor driver is boosted; and suppressing the DC bus voltage of the motor driver based on the bus voltage suppression strategy of current limitation. The technical problems that an existing method for improving the grid-side power factor of the film capacitor motor driver is too high in cost and needs maintenance are solved.

Description

Technical Field

[0001] The present application relates to the field of motor control, and in particular to a control method and electronic equipment for a motor driver. Background Art

[0002] Motors are divided into synchronous motors and asynchronous motors according to whether the rotor speed is synchronized with the electrical frequency. The rotor rotation speed of a synchronous motor is consistent with the speed of the rotating magnetic field generated by the stator, while the rotor rotation speed of an asynchronous motor is inconsistent with the speed of the stator magnetic field. Synchronous motors are suitable for occasions that require precise speed control, while asynchronous motors are suitable for occasions where speed regulation requirements are not high. Synchronous motors have been widely used in the fields of industry and household appliances due to their simple structure, high power density, and good debugging performance.

[0003] In motor drivers, affected by factors such as the use environment, three-phase input electrolytic capacitor synchronous motor drivers use large capacitors to achieve bus voltage smoothing and stabilization, while the short life of electrolytic capacitors limits the life of the drive system. The life of electrolytic capacitors on the DC bus side is generally shorter than that of other devices. In order to improve the reliability and life of the drive system, the motor driver can use small-capacitance film capacitors to replace large electrolytic capacitors on the DC side to improve the overall reliability of the motor driver. Combined with three-phase uncontrolled rectification, it has many advantages, such as low price and simple structure. However, it also faces many challenges. For example, due to the small bus capacitance, the input power factor is low, especially when multiple drivers are connected in parallel. However, there are requirements for the power factor of power grid users, so the following measures need to be taken: ① Add a power factor correction device on the grid side; ② Install a phase-shifting transformer; ③ Use a power factor correction (PFC) circuit on the controller; ④ The controller uses active rectification. ① and ② This will increase the user's cost equipment and require additional installation sites. ③ and ④ will increase the controller cost, which also needs to be borne by the user and cannot be achieved on the film capacitor driver. Therefore, in order to expand the application field of electrolytic capacitor-free motor drives, it is of great significance to implement a grid-side power factor improvement control strategy that takes into account the dynamic performance of the motor through a control algorithm.

[0004] At the same time, the capacitance of membrane capacitors is often relatively small. Compared with traditional electrolytic capacitors, film capacitors have small capacity and relatively poor filtering effect. When the motor decelerates, it is in a power generation state. Due to the small capacitance, it cannot store too much energy and is prone to overvoltage. In severe cases, it may even damage the inverter. Therefore, how to suppress overvoltage is also an important issue in the application of membrane capacitors.

[0005] To address the above problems, no effective solution has been proposed yet. Summary of the invention

[0006] The embodiments of the present application provide a control method and electronic device for a motor driver, which at least solve the problem that the existing method for improving the grid-side power factor of a film capacitor motor driver is too costly and requires maintenance.

[0007] According to one aspect of an embodiment of the present application, a method for improving the grid-side power factor of a motor driver is provided, including: improving the grid-side power factor of the motor driver based on a harmonic suppression strategy based on bus disturbance following, wherein the method includes the following steps: acquiring a DC bus voltage currently detected in the circuit; performing low-pass filtering on the DC bus voltage to obtain a first voltage; performing analog filtering on the DC bus voltage to obtain a second voltage; improving the grid-side power factor of the motor driver according to the first voltage, the second voltage and the voltage obtained after suppressing the DC bus voltage; and suppressing the DC bus voltage of the motor driver based on a bus voltage suppression strategy based on current limiting.

[0008] Optionally, boosting the grid-side power factor of the motor driver based on the first voltage, the second voltage and the voltage obtained after suppressing the DC bus voltage includes: determining the voltage difference between the first voltage and the second voltage; taking the voltage difference as the disturbance amount of the DC bus voltage; boosting the grid-side power factor of the motor driver based on the disturbance amount and the voltage obtained after suppressing the DC bus voltage.

[0009] Optionally, the grid-side power factor of the motor driver is improved according to the disturbance amount and the voltage obtained after suppressing the DC bus voltage, including: proportionally controlling the disturbance amount to obtain a first voltage compensation amount and a second voltage compensation amount; superimposing the first voltage compensation amount on the voltage component of the output voltage of the motor driver on the d-axis of the dq coordinate system to obtain a first output voltage on the d-axis, wherein the output voltage is determined according to the voltage obtained after suppressing the DC bus voltage; superimposing the second voltage compensation amount on the voltage component of the output voltage of the motor driver on the q-axis of the dq coordinate system to obtain a second output voltage on the q-axis; and improving the grid-side power factor of the motor driver according to the first output voltage and the second output voltage.

[0010] Optionally, improving the grid-side power factor of the motor driver according to the first output voltage and the second output voltage includes: performing space vector pulse width modulation using the first output voltage and the second output voltage to obtain a modulation signal; and controlling the motor using the modulation signal.

[0011] Optionally, the above method also includes: when using the first output voltage and the second output voltage to perform space vector pulse width modulation, when the frequency of the carrier used to generate the pulse width modulation signal is lower than the first preset frequency, triggering two interrupts in each pulse width modulation signal cycle to update the waveform parameters of the pulse width modulation signal; when the frequency of the carrier used to generate the pulse width modulation signal is higher than the second preset frequency, triggering one interrupt in each pulse width modulation signal cycle to update the waveform parameters of the pulse width modulation signal.

[0012] Optionally, a bus voltage suppression strategy based on current limitation is used to suppress the DC bus voltage of the motor driver, including: performing PI adjustment on the currently detected DC bus voltage and the detected maximum DC bus voltage to obtain a current limiting value on the q-axis of the dq coordinate system; and suppressing the DC bus voltage according to the current limiting value on the q-axis and the actual current on the q-axis.

[0013] Optionally, the DC bus voltage is suppressed according to the current limit value on the q-axis and the actual current on the q-axis, including: performing low-pass filtering on the actual current on the q-axis to obtain the current value after low-pass filtering; performing PI adjustment on the current value after low-pass filtering and the current limit value on the q-axis to output a frequency limit value; when it is detected that the DC bus voltage is higher than a preset voltage, using the frequency limit value to limit the maximum frequency change per unit time of the motor controller.

[0014] According to another aspect of an embodiment of the present application, there is also provided an electronic device, including: a processor, and a memory storing a program, wherein the program includes instructions, and when the instructions are executed by the processor, the processor executes the above method.

[0015] According to another aspect of the embodiments of the present application, a non-transitory machine-readable medium storing computer instructions is also provided, where the computer instructions are used to enable a computer to execute the above method.

[0016] According to another aspect of the embodiments of the present application, a computer program product is provided, including a computer program, which is used to enable the computer to execute the above method when the computer program is executed by a processor of the computer.

[0017] Beneficial effects of the embodiments of the present application:

[0018] In an embodiment of the present application, a harmonic suppression strategy based on bus disturbance following is adopted to improve the grid-side power factor of the motor driver, wherein the method includes the following steps: obtaining the DC bus voltage currently detected in the circuit; performing low-pass filtering on the DC bus voltage to obtain a first voltage; performing analog filtering on the DC bus voltage to obtain a second voltage; improving the grid-side power factor of the motor driver according to the first voltage and the second voltage; suppressing the DC bus voltage of the motor driver based on a current-limited bus voltage suppression strategy, by using a software algorithm on the basis of an uncontrolled rectifier architecture to improve the grid-side power factor of the membrane capacitor motor driver and suppress the DC bus voltage, thereby achieving the technical effect of reducing the pollution of the equipment to the grid side, and improving the grid-side power factor of the membrane capacitor motor driver without adding additional circuits, and the method has many advantages of low cost, high reliability, and easy implementation.

[0019] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can be obtained based on these drawings without creative work.

[0021] Figure 1a It is a schematic diagram of an existing method for improving the grid-side power factor when multiple membrane capacitor drivers are connected in parallel;

[0022] Figure 1b It is a schematic diagram of another existing method for improving the grid-side power factor when multiple membrane capacitor drivers are connected in parallel;

[0023] Figure 1c It is a schematic diagram of a method for improving the grid-side power factor when multiple membrane capacitor drivers are connected in parallel according to an embodiment of the present application;

[0024] Figure 2 is a hardware topology diagram of a motor driver according to an embodiment of the present application;

[0025] Figure 3 is a system control block diagram of a motor driver according to an embodiment of the present application;

[0026] Figure 4 is a system control flow chart of a motor driver according to an embodiment of the present application;

[0027] Figure 5 is a flow chart of a method for improving the grid-side power factor of a motor driver according to an embodiment of the present application;

[0028] Figure 6 yes Figure 4 Schematic diagram of the harmonic suppression strategy based on bus disturbance following mentioned in;

[0029] Figure 7 yes Figure 4 Schematic diagram of the bus voltage suppression strategy based on current limitation mentioned in;

[0030] Figure 8 It is a schematic diagram of the grid-side harmonic suppression effect before using the power factor improvement method proposed in this application;

[0031] Fig. 9 It is a schematic diagram of the grid-side harmonic suppression effect after using the power factor improvement method proposed in this application;

[0032] Fig.10 is a schematic diagram of the overvoltage suppression effect before using the overvoltage suppression method proposed in the present application;

[0033] Fig.11 is a schematic diagram of the overvoltage suppression effect after using the overvoltage suppression method proposed in this application;

[0034] Fig.12 Schematic diagram of the structure of the electronic device of this embodiment. DETAILED DESCRIPTION

[0035] Embodiments of the present embodiment will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present embodiment are shown in the accompanying drawings, it should be understood that the present embodiment can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein, which are instead provided for a more thorough and complete understanding of the present embodiment. It should be understood that the drawings and embodiments of the present embodiment are only for exemplary purposes and are not intended to limit the scope of protection of the present embodiment.

[0036] In order to better understand the embodiments of the present application, the technical terms involved in the embodiments of the present application are explained as follows:

[0037] Film capacitors, also known as film capacitors, are capacitors that use plastic film as a dielectric. This type of capacitor usually uses polyester, polypropylene, polyphenylene sulfide, polytetrafluoroethylene and other materials as its dielectric layer. Film capacitors are widely used in various electronic devices due to their high stability and reliability.

[0038] A motor driver is an electronic device used to control the operation of a motor. It receives instructions from a controller (such as a microcontroller, PLC, etc.) and converts these instructions into electrical signals that can drive the motor to work.

[0039] Three-phase uncontrolled rectification is a technology that converts three-phase AC power into DC power. It uses the unidirectional conductivity of diodes to achieve this process. Unlike controlled rectification, the components (usually diodes) in the uncontrolled rectification circuit cannot be controlled by external signals to turn on or off, so the output DC voltage and current mainly depend on the input AC voltage.

[0040] Power factor is an important indicator to measure the effective utilization of electric energy in AC power system. It is defined as the ratio between active power (electric power actually consumed to do useful work, in watts W) and apparent power (total input electric power, in volt-amperes VA). The ideal power factor is 1, which means that all input power is effectively converted into useful work; while a power factor below 1 means that part of the power is not fully utilized.

[0041] Inversion is a key process in the field of power electronics. It refers to the process of converting direct current (DC) into alternating current (AC). This process is achieved through an inverter, which is a power conversion device that can adjust the frequency, voltage and waveform of the output AC according to specific needs. Inversion technology plays an important role in many applications, especially when it is necessary to convert the DC power provided by energy storage devices (such as batteries or solar panels) into AC power suitable for the grid or load.

[0042] In related technologies, in order to improve the reliability and life of the drive system, the motor driver can use a small-capacitance film capacitor to replace the large electrolytic capacitor on the DC side to improve the overall reliability of the motor driver. Combined with three-phase uncontrolled rectification, it has many advantages, such as low price and simple structure. However, due to the small bus capacitance, the input power factor is low, especially when multiple drivers are connected in parallel, and the power grid users have requirements for the power factor.

[0043] At present, membrane capacitor drive systems generally use the following methods to improve the power factor on the grid side: Figure 1a The method of installing the phase-shifting transformer as shown, or Figure 1b The method of adding a power factor correction device on the grid side is shown.

[0044] Figure 1a The solution shown requires adding a transformer, which takes up space, is costly, and requires additional equipment maintenance. Figure 1b The solution shown requires the addition of power factor correction equipment, which also requires space, is costly, and requires additional equipment maintenance.

[0045] In addition, the capacitance of film capacitors is often relatively small. Compared with traditional electrolytic capacitors, film capacitors have small capacity and relatively poor filtering effect. When the motor is decelerating, it is in a power generation state. Due to the small capacitance, it cannot store too much energy and is prone to overvoltage. In severe cases, it may even damage the inverter.

[0046] In order to solve the above problems, relevant solutions are provided in the embodiments of the present application, which are described in detail below.

[0047] This application uses a conventional inverter control hardware topology and a pure software algorithm to improve the power factor. The core idea is that the low-pollution controller analyzes and calculates the additional Ud and Uq required to improve the current grid-side power factor based on the current bus voltage fluctuation information, and performs relevant superposition during inversion to improve the grid-side power factor. Figure 1c is a schematic diagram of a method for improving the grid-side power factor when multiple membrane capacitor drivers are connected in parallel according to an embodiment of the present application, such as Figure 1c As shown, by adopting the power factor improvement method provided by the present application, no additional equipment is required when multiple membrane capacitor drivers are connected in parallel.

[0048] Figure 2 is a hardware topology diagram of a motor driver according to an embodiment of the present application, such as Figure 2 As shown in the figure, the motor driver mainly consists of two parts: a rectifier and an inverter, and each driver uses the same hardware topology.

[0049] Figure 3 is a system control block diagram of a motor driver according to an embodiment of the present application, Figure 4 is a system control flow chart of a motor driver according to an embodiment of the present application, such as Figure 3 , Figure 4 As shown, the low-pollution controller includes: a harmonic suppression strategy based on bus disturbance following and a bus voltage suppression strategy based on current limitation. The former is used to improve the grid-side power factor of the motor drive, and the latter is used to achieve overvoltage suppression.

[0050] The following describes the method for improving the grid-side power factor and suppressing overvoltage of the membrane capacitor driver proposed in the present application in conjunction with specific embodiments.

[0051] Figure 5 is a flow chart of a motor drive control method according to an embodiment of the present application, such as Figure 5 As shown, the method comprises the following steps:

[0052] Step S502, improving the grid-side power factor of the motor drive based on the harmonic suppression strategy of bus disturbance following, wherein this step includes the following sub-steps:

[0053] Step S5021, obtaining the DC bus voltage currently detected in the circuit.

[0054] DC Bus Voltage refers to the voltage at the common connection point or line used to transmit and distribute direct current in power electronic equipment and systems. It plays a vital role in various applications, including but not limited to inverters, motor drives, uninterruptible power supplies, solar photovoltaic systems, and electric vehicles.

[0055] Step S5022: low-pass filter the DC bus voltage to obtain a first voltage.

[0056] In this step, a low-pass filter (LPF) is used to perform low-pass filtering on the DC bus voltage in order to remove high-frequency noise in the signal and retain useful low-frequency components to ensure system stability and performance.

[0057] An LPF is an electronic filter that allows signals below a certain frequency (called the cutoff frequency) to pass through while attenuating signals above that frequency. LPFs are widely used in both analog and digital circuits to remove unwanted high-frequency noise, smooth signals, or as part of more complex systems such as audio processing, modulation and demodulation in communication systems, power supply filtering, etc.

[0058] Step S5023, performing analog filtering processing on the DC bus voltage to obtain a second voltage.

[0059] In this step, the analog filter (Audio Frequency, AF) is used to perform analog filtering on the same voltage signal in step S502 in order to reduce the ripple and other high-frequency noise components on the voltage, thereby improving the power quality or ensuring the stable operation of sensitive electronic equipment.

[0060] Step S5024, boosting the grid-side power factor of the motor driver according to the first voltage, the second voltage, and the voltage obtained after suppressing the DC bus voltage.

[0061] When executing step S5024, further calculation processing is performed based on the voltage obtained after low-pass filtering in step S5022, the voltage obtained after analog filtering in step S5023, and the voltage obtained after suppressing the DC bus voltage, thereby improving the grid-side power factor of the motor driver.

[0062] Step S504: suppressing the DC bus voltage of the motor driver based on the bus voltage suppression strategy of current limitation.

[0063] Through the above method, on the basis of the uncontrolled rectifier architecture, a software algorithm is used to improve the grid-side power factor of the membrane capacitor motor driver and suppress the DC bus voltage, thereby reducing the pollution of the equipment to the grid side. The technical effect of improving the grid-side power factor of the membrane capacitor motor driver can be achieved without adding additional circuits.

[0064] According to an optional embodiment of the present application, step S5024 is executed to boost the grid-side power factor of the motor driver according to the first voltage, the second voltage and the voltage obtained after suppressing the DC bus voltage, by the following method: determining the voltage difference between the first voltage and the second voltage; taking the voltage difference as the disturbance amount of the DC bus voltage; and boosting the grid-side power factor of the motor driver according to the disturbance amount and the voltage obtained after suppressing the DC bus voltage.

[0065] Figure 6 yes Figure 4 The schematic diagram of the harmonic suppression strategy based on bus disturbance following mentioned in Figure 6 As shown, for the current DC bus voltage (U dc ) performs an LPF low-pass filter and an AF analog filter at the same time. The difference between the two is used as the winding amount of the DC bus voltage. Then, the grid-side power factor of the motor drive is improved based on the disturbance amount and the voltage obtained after suppressing the DC bus voltage.

[0066] According to another optional embodiment of the present application, the grid-side power factor of the motor driver is improved according to the disturbance amount and the voltage obtained after suppressing the DC bus voltage, including the following steps: proportionally controlling the disturbance amount to obtain a first voltage compensation amount and a second voltage compensation amount; superimposing the first voltage compensation amount on the voltage component of the output voltage of the motor driver on the d-axis of the dq coordinate system to obtain a first output voltage on the d-axis, wherein the output voltage is determined according to the voltage obtained after suppressing the DC bus voltage; superimposing the second voltage compensation amount on the voltage component of the output voltage of the motor driver on the q-axis of the dq coordinate system to obtain a second output voltage on the q-axis; and improving the grid-side power factor of the motor driver according to the first output voltage and the second output voltage.

[0067] As mentioned above, for the current DC bus voltage (U dc) performs LPF low-pass filtering, and performs an AF analog filtering at the same time, and the difference between the two is used as the winding amount of the DC bus voltage. In this embodiment, the compensation amount Δud (i.e., the above-mentioned first voltage compensation amount) and Δuq (i.e., the above-mentioned second voltage compensation amount) obtained after the disturbance beam is proportionally controlled are respectively superimposed on the dq voltage to obtain the final output voltage udout (i.e., the first output voltage on the d-axis) and uqout (i.e., the second output voltage on the q-axis). Next, the grid-side power factor of the motor driver is improved according to the first output voltage on the d-axis and the second output voltage on the q-axis.

[0068] The winding moment is input into a proportional controller, and the compensation values ​​Δud and Δuq are calculated according to the set proportional gain. This step is to ensure that the compensation value can respond quickly to the change of DC bus voltage while maintaining the stability of the system.

[0069] In the field of motor control and power electronics, especially when it comes to the analysis of the synchronous rotating coordinate system (dq coordinate system), Uq and Uq represent the voltage components in this coordinate system. Specifically:

[0070] The dq coordinate system is a technique for transforming variables in a three-phase stationary coordinate system (abc coordinate system) to a two-phase rotating coordinate system. This transformation is often called Park Transformation (Park), which helps to simplify the dynamic modeling and control of AC motors (such as induction motors and permanent magnet synchronous motors).

[0071] d-axis: corresponds to the direction of the motor rotor magnetic field and is mainly related to excitation.

[0072] q-axis: perpendicular to the d-axis, mainly related to torque generation.

[0073] Ud: This is the voltage component on the d-axis.

[0074] Uq: This is the voltage component on the q axis, which is mainly used to generate electromagnetic torque.

[0075] In this embodiment, a bus voltage suppression strategy based on current limitation is also provided for suppressing the DC bus voltage of the motor driver (described below). In this step, the output voltage of the motor driver is determined based on the suppressed DC bus voltage. By superimposing the suppression result of the DC bus voltage and the voltage compensation amount, the improvement effect of the grid-side power factor of the motor driver can be further improved.

[0076] As some optional embodiments of the present application, the grid-side power factor of the motor driver is improved according to the first output voltage and the second output voltage, which is achieved by the following method: using the first output voltage and the second output voltage to perform space vector pulse width modulation to obtain a modulation signal; and using the modulation signal to control the motor.

[0077] In an embodiment of the present application, space vector pulse width modulation (SVPWM) is performed according to the final output voltages udout and uqou for controlling the motor to improve the power factor.

[0078] The basic idea of ​​SVPWM is to regard the inverter as a space vector generator that can generate different voltage vectors. By reasonably selecting and combining these basic voltage vectors, the required circular rotating magnetic field is synthesized to drive the motor.

[0079] As an optional embodiment of the present application, when space vector pulse width modulation is performed using the first output voltage and the second output voltage, when the frequency of the carrier used to generate the pulse width modulation signal is lower than the first preset frequency, two interrupts are triggered in each pulse width modulation signal cycle to update the waveform parameters of the pulse width modulation signal, and when the frequency of the carrier used to generate the pulse width modulation signal is higher than the second preset frequency, one interrupt is triggered in each pulse width modulation signal cycle to update the waveform parameters of the pulse width modulation signal.

[0080] In the embodiment of the present application, in order to ensure control performance, during the SVPWM modulation process, special processing is performed on the low carrier and the high carrier. The low carrier is updated by dual interruption, and the high carrier is updated by single interruption.

[0081] At low carrier frequencies, dual interrupt updates can more finely control the inverter output waveform. Specifically, the following advantages exist:

[0082] More precise waveform control: Dual interrupts allow two updates within one carrier cycle, which means the switching state of the inverter can be adjusted more frequently within each carrier cycle, thereby improving the control accuracy of the output voltage waveform.

[0083] Reduce harmonic distortion: By adjusting the PWM signal more carefully, the harmonic components in the output waveform can be effectively reduced and the power quality can be improved.

[0084] Adapt to rapidly changing load conditions: For systems that require fast response, such as high-performance motor control systems, dual interrupt updates help adapt to load changes more quickly, maintaining system stability and responsiveness.

[0085] At high carrier frequencies, single interrupt updates are usually chosen for the following reasons:

[0086] Simplify control logic: As the carrier frequency increases, the time of each carrier cycle becomes shorter. If dual interrupts are still used, it may bring too much computational burden to the control system. Single interrupt update reduces the number of interrupts in each carrier cycle and reduces the processor load.

[0087] Sufficient control accuracy: At a higher carrier frequency, even if only one interrupt update is performed, since the carrier cycle itself is already very short, it can still provide sufficiently high control accuracy.

[0088] Reduced interrupt overhead: Frequent interrupts can take up a lot of CPU time, especially when microcontroller resources are limited. Single interrupt updates can effectively reduce this overhead, allowing the processor to have more time for other tasks.

[0089] In summary, the strategy of "double interruption update for low carrier and single interruption update for high carrier" is based on the optimal trade-off between system performance and resource utilization under different carrier frequency conditions, aiming to provide the best control effect for various application scenarios.

[0090] The method for improving the grid-side power factor of the above-mentioned motor driver provided in the embodiment of the present application uses a software algorithm to improve the grid-side power factor of the membrane capacitor motor driver on the basis of an uncontrolled rectifier architecture, thereby reducing the pollution of the equipment to the grid side. The technical effect of improving the grid-side power factor of the membrane capacitor motor driver can be achieved without adding additional circuits. The method has many advantages of low cost, high reliability and easy implementation.

[0091] In addition, the above-mentioned solution provided in the present application, by improving the grid-side power factor of the motor driver, means that less reactive current flows in the power grid, thereby reducing losses in the process of power transmission and distribution; at the same time, it reduces the apparent power demand in the power system, thereby reducing the total amount of electricity that the power plant needs to generate, indirectly reducing energy consumption, and achieving the technical effect of reducing air pollution.

[0092] In other optional embodiments of the present application, executing step S504 to suppress the DC bus voltage of the motor driver based on the current limiting bus voltage suppression strategy is achieved by the following method: PI adjustment is performed on the currently detected DC bus voltage and the detected maximum DC bus voltage to obtain the current limiting value on the q-axis of the dq coordinate system; the DC bus voltage is suppressed according to the current limiting value on the q-axis and the actual current on the q-axis.

[0093] As an optional embodiment of the present application, the DC bus voltage is suppressed according to the current limit value on the q-axis and the actual current on the q-axis, including the following steps: low-pass filtering the actual current on the q-axis to obtain the current value after low-pass filtering; PI-adjusting the current value after low-pass filtering and the current limit value on the q-axis to output a frequency limit value; when it is detected that the DC bus voltage is higher than the preset voltage, using the frequency limit value to limit the maximum frequency change per unit time of the motor controller.

[0094] Figure 7 yes Figure 4 The schematic diagram of the bus voltage suppression strategy based on current limitation mentioned in Figure 7 As shown, PI adjustment is performed based on the highest DC bus voltage Udcmax currently detected by the system and compared with the actually measured DC bus voltage Udc to obtain the q-axis current limit value iqmax. After the actual q-axis current is low-pass filtered, PI adjustment is performed with iqmax. The PI output is used as the maximum frequency change limit fmax_err. This value is used for the given frequency limit. When the bus voltage is too high, the maximum frequency change per unit time of the motor controller is limited to reduce energy feedback, thereby suppressing voltage increase.

[0095] The parameters in the method provided in the present application are obtained through real-time correction through online identification, which greatly improves the stability of the system; and there is no need to increase the system cost, solves the problem of improving the power factor on the grid side of the motor driver, and ensures higher dynamic performance of the motor.

[0096] Figure 8 and Fig. 9 They are schematic diagrams of the grid-side harmonic suppression effect before and after using the power factor improvement method proposed in this application, such as Figure 8 and Fig. 9 As shown in the figure, after use, the input current harmonics are greatly reduced, the harmonic content is reduced from 86.4% to 32.6%, and the power factor is increased from 75.6% to 95%.

[0097] Fig.10 and Fig.11 They are schematic diagrams of the overvoltage suppression effect before and after using the overvoltage suppression method proposed in this application, such as Fig.10 and Fig.11 As shown, an overvoltage fault occurs before use, but after use, the rapid change of bus voltage can be obviously suppressed.

[0098] Fig.10 The parameters are set as follows: overvoltage point 700V, speed 85Hz, deceleration time 0.5s, deceleration base frequency 120Hz, overvoltage stall protection gain 30.

[0099] Note: The deceleration time is set to about 0.5s, the actual bus voltage overshoots, and an overvoltage fault error is reported.

[0100] Fig.11 The parameters are set as follows: overvoltage point 700V, speed 85Hz, deceleration time 1s, deceleration reference frequency 120Hz, overvoltage stall protection gain 30;

[0101] The deceleration time is set to about 0.5s for rapid deceleration, the bus voltage is controlled at around 700V, there is no overvoltage, and the actual deceleration time is about 4.2s.

[0102] The method for improving the grid-side power factor and the overvoltage suppression method of the motor driver proposed in this application adopts a pure software method to achieve grid-side power factor improvement and controller bus overvoltage limitation under small capacitance state, without increasing hardware cost, easy to debug, and highly robust; it can ensure higher motor dynamic performance; and it does not rely on motor parameters, so it is not affected by the motor operating state; in addition, this solution can be used for position sensorless control.

[0103] The technical solution proposed in this application does not require additional equipment when multiple drivers are connected in parallel.

[0104] The embodiment of the present application also provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication. The memory stores a computer program executable by the at least one processor, and the computer program is used to enable the electronic device to perform the method of the embodiment of the present application when executed by the at least one processor.

[0105] An embodiment of the present application also provides a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method of the embodiment of the present application.

[0106] The embodiment of the present application also provides a computer program product, including a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method of the embodiment of the present application.

[0107] refer to Fig.12, the structural block diagram of the electronic device that can be used as the server or client of the embodiment of the present application will now be described, which is an example of the hardware device that can be applied to various aspects of the present application. The electronic device is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only examples, and are not intended to limit the implementation of the present application described and / or required herein.

[0108] like Fig.12 As shown, the electronic device includes a computing unit 1201, which can store data stored in a read-only memory (ROM)

[0109] The computer program in the computing unit 1201, the ROM 1202 or the computer program loaded from the storage unit 1208 into the random access memory (RAM) 1203 is used to perform various appropriate actions and processes. In the RAM 1203, various programs and data required for the operation of the electronic device can also be stored. The computing unit 1201, the ROM 1202 and the RAM 1203 are connected to each other via a bus 1204. An input / output (I / O) interface 1205 is also connected to the bus 1204.

[0110] Multiple components in the electronic device are connected to the I / O interface 1205, including: an input unit 1206, an output unit 1207, a storage unit 1208, and a communication unit 1209. The input unit 1206 can be any type of device that can input information to the electronic device, and the input unit 1206 can receive input digital or character information, and generate key signal input related to user settings and / or function control of the electronic device. The output unit 1207 can be any type of device that can present information, and can include but is not limited to a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 1208 can include but is not limited to a disk, an optical disk. The communication unit 1209 allows the electronic device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks, and can include but is not limited to a modem, a network card, an infrared communication device, a wireless communication transceiver, and / or a chipset, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0111] The computing unit 1201 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 1201 include, but are not limited to, a CPU, a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 1201 performs the various methods and processes described above. For example, in some embodiments, the method embodiments of the present application may be implemented as a computer program, which is tangibly contained in a machine-readable medium, such as a storage unit 1208. In some embodiments, part or all of the computer program may be loaded and / or installed on an electronic device via ROM 1202 and / or communication unit 1209. In some embodiments, the computing unit 1201 may be configured to perform the above method in any other appropriate manner (e.g., by means of firmware).

[0112] The computer program for implementing the method of the embodiment of the present application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0113] In the context of the present application embodiment, machine-readable medium can be a tangible medium that can contain or store a program for use by an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable signal medium can include but is not limited to electronic, magnetic, optical, electromagnetic or infrared systems, devices or equipment, or any suitable combination of the above. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0114] It should be noted that the term "including" and its variations used in the embodiments of the present application are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present application are illustrative and not restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0115] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0116] The various steps described in the method implementation methods provided in the embodiments of the present application can be performed in different orders and / or in parallel. In addition, the method implementation methods may include additional steps and / or omit the steps shown. The scope of protection of the present application is not limited in this respect.

[0117] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments refer to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0118] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A control method for a motor driver, characterized in that: include: The grid-side power factor of the motor driver is improved based on the harmonic suppression strategy of bus disturbance following, wherein the method comprises the following steps: obtaining the DC bus voltage currently detected in the circuit; performing low-pass filtering on the DC bus voltage to obtain a first voltage; performing analog filtering on the DC bus voltage to obtain a second voltage; improving the grid-side power factor of the motor driver according to the first voltage, the second voltage and the voltage obtained after suppressing the DC bus voltage; A bus voltage suppression strategy based on current limitation suppresses the DC bus voltage of the motor driver.

2. The method according to claim 1, characterized in that The grid-side power factor of the motor driver is increased according to the first voltage, the second voltage and the voltage obtained after suppressing the DC bus voltage, including: determining a voltage difference between the first voltage and the second voltage; Taking the voltage difference as the disturbance amount of the DC bus voltage; The grid-side power factor of the motor driver is improved according to the disturbance amount and a voltage obtained after suppressing the DC bus voltage.

3. The method according to claim 2, characterized in that Improving the grid-side power factor of the motor driver according to the disturbance amount and the voltage obtained after suppressing the DC bus voltage, including: Proportional control is performed on the disturbance amount to obtain a first voltage compensation amount and a second voltage compensation amount; Superimposing the first voltage compensation amount on the voltage component of the output voltage of the motor driver on the d-axis of the dq coordinate system to obtain a first output voltage on the d-axis, wherein the output voltage is determined according to a voltage obtained after suppressing the DC bus voltage; Superimposing the second voltage compensation amount on the voltage component of the output voltage of the motor driver on the q-axis of the dq coordinate system to obtain a second output voltage on the q-axis; The grid-side power factor of the motor driver is improved according to the first output voltage and the second output voltage.

4. The method according to claim 3, characterized in that Improving the grid-side power factor of the motor driver according to the first output voltage and the second output voltage includes: Performing space vector pulse width modulation using the first output voltage and the second output voltage to obtain a modulated signal; The motor is controlled using the modulation signal.

5. The method according to claim 4, characterized in that The method further comprises: When space vector pulse width modulation is performed using the first output voltage and the second output voltage, when the frequency of the carrier used to generate the pulse width modulation signal is lower than the first preset frequency, two interruptions are triggered in each pulse width modulation signal cycle to update the waveform parameters of the pulse width modulation signal; when the frequency of the carrier used to generate the pulse width modulation signal is higher than the second preset frequency, one interruption is triggered in each pulse width modulation signal cycle to update the waveform parameters of the pulse width modulation signal.

6. The method according to claim 1, characterized in that The bus voltage suppression strategy based on current limitation suppresses the DC bus voltage of the motor driver, including: The currently detected DC bus voltage and the detected maximum DC bus voltage are subjected to PI regulation to obtain a current limit value on the q-axis of the dq coordinate system; The DC bus voltage is suppressed according to the current limit value on the q-axis and the actual current on the q-axis.

7. The method according to claim 6, characterized in that The DC bus voltage is suppressed according to the current limit value on the q-axis and the actual current on the q-axis, including: Performing low-pass filtering on the actual current on the q-axis to obtain a current value after low-pass filtering; Perform PI adjustment on the current value after low-pass filtering and the current limit value on the q-axis to output a frequency limit value; When it is detected that the DC bus voltage is higher than a preset voltage, the frequency limit value is used to limit the maximum frequency variation per unit time of the motor controller.

8. An electronic device comprising: A processor and a memory storing a program, wherein the program comprises instructions, which, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 7.

9. A non-transitory machine-readable medium storing computer instructions, characterized in that: The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor of a computer, the computer is used to cause the computer to execute the method according to any one of claims 1 to 7.

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