Motor signal feedback control method and device based on PWM

Abstract

The invention discloses a PWM-based motor signal feedback control method and device, and the device comprises a signal feedback circuit which is disposed on a motor or can be connected with the motor so as to receive a motor feedback signal, and can output a control signal. The method comprises the following steps: setting N different first function relational expressions established by motor state feedback signals and PWM duty ratios d in a main control board, and defining a PWM duty ratio range for each first function relational expression, and the PWM duty ratio ranges are not overlapped; setting A different second function relational expressions established by the motor state feedback signals and the PWM frequency f in the main control board, and defining a PWM frequency f range for each second function relational expression, and the PWM frequency ranges are not overlapped; the main control board accurately adjusts the target value of the motor in real time according to the multiple motor state feedback signals, meanwhile, the hardware structure of the main control board and the hardware structure of the motor are simplified, and cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a motor signal feedback control method and device based on PWM. Background Art

[0002] In traditional motor control systems, PWM technology is widely used to adjust the speed, torque and other output characteristics of the motor. PWM is an effective power control method that controls the average voltage and thus the performance of the motor by changing the width of the voltage pulse applied to the motor. However, traditional systems usually lack an effective feedback mechanism to ensure that the motor operates in the optimal state, especially in the face of load changes or environmental conditions.

[0003] In order to cooperate with the HVAC system motherboard, the existing PSC motor or PWM motor is generally controlled through open loop control, or only controlled by a feedback speed signal, resulting in the problem that the motor state cannot be accurately controlled through the HVAC system motherboard.

[0004] The present invention is made based on the above situation. Summary of the invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a motor signal feedback control method and device based on PWM.

[0006] The present invention is achieved through the following technical solutions:

[0007] A motor signal feedback control method based on PWM includes a signal feedback circuit arranged on the motor or connected to the motor so as to receive the motor feedback signal and output a control signal. The method includes

[0008] S1. A first functional relationship between N different motor state feedback signals and PWM duty cycle d is set in the main control board, and a PWM duty cycle range is defined for each first functional relationship, and the PWM duty cycle ranges do not overlap with each other; A second functional relationship between A different motor state feedback signals and PWM frequency f is set in the main control board, and a PWM frequency f range is defined for each second functional relationship, and the PWM frequency ranges do not overlap with each other;

[0009] S2, the motor outputs the PWM duty cycle signal and PWM frequency signal corresponding to each motor state feedback signal to the main control board;

[0010] S3. The main control board determines the type of motor state feedback signal according to the received PWM signal duty cycle range and PWM frequency range, and calculates the actual value of each motor state feedback signal according to the corresponding first functional relationship and second functional relationship. The main control board adjusts the motor target value according to the actual value of each motor state feedback signal.

[0011] In S1, a sending cycle of the motor is set, and the sending cycle is divided into M sending cycle time periods, and the motor is set to feedback PWM duty cycle signals corresponding to different motor state feedback signals in different sending cycle time periods. The motor outputs the PWM duty cycle signals corresponding to each motor state feedback signal to the main control board according to the sending cycle timing cycle.

[0012] In the PWM-based motor signal feedback control method as described above, N, M and A in S1 are all integers, and N>1, A>1, and M≥N.

[0013] As described above, a motor signal feedback control method based on PWM is provided in the motor, wherein a motor driving module for driving the motor to rotate is provided in the motor, and a motor control module connected to the motor driving module for controlling the motor rotation and capable of initializing motor-related variables and extracting motor operating parameters, the motor control module is connected to a plurality of motor state signal feedback duty cycle function modules for converting corresponding motor-related operating parameters into corresponding motor state signal duty cycles, and a sending signal time counter for calculating the sending signal time; a first receiving signal module for receiving a PWM duty cycle signal and identifying a corresponding motor state feedback signal according to a duty cycle range is provided on the main control board, the first receiving signal module is connected to a plurality of motor state feedback signal decoding modules for calculating the actual value of the corresponding motor state feedback signal by using a first functional relationship corresponding to the motor state feedback signal type according to the PWM duty cycle signal, and the motor state signal feedback module is connected to a main control board control module capable of adjusting the motor target quantity according to the actual value of each motor state feedback signal.

[0014] As described above, a PWM-based motor signal feedback control method is provided on the motor, wherein a control signal parsing module for parsing the motor control signal is connected to the control signal parsing module with multiple motor state signal feedback frequency function modules for converting the corresponding motor control signal into the corresponding motor state signal frequency, and a sending signal time counter for calculating the sending signal time; a second receiving signal module is provided on the main control board for receiving the PWM frequency signal and identifying the corresponding motor state feedback signal according to the frequency range, the second receiving signal module is connected to multiple motor state signal feedback modules for calculating the actual value of the corresponding motor state feedback signal through the second functional relationship of the corresponding motor state feedback signal type according to the PWM frequency signal, and the motor state signal feedback module is connected to a main control board control module capable of adjusting the motor target quantity according to the actual value of each motor state feedback signal.

[0015] In the motor signal feedback control method based on PWM as described above, the motor is also provided with a fault detection interrupt module for fault detection, the fault detection interrupt module is connected to a plurality of fault function modules which convert corresponding motor fault signals into corresponding motor fault signal frequencies; a third receiving signal module which receives the motor fault signal frequency and identifies the motor fault feedback signal according to the frequency range is provided on the main control board, the third receiving signal module is connected to a plurality of motor fault feedback modules which calculate the actual value of the corresponding motor fault feedback signal through the second functional relationship of the corresponding motor fault feedback signal type using the PWM frequency signal, and the main control board control module adjusts the motor target quantity according to the actual value of each motor fault feedback signal.

[0016] In the PWM-based motor signal feedback control method as described above, the motor target quantity is a speed target quantity, a torque target quantity, or an air volume target quantity.

[0017] In the PWM-based motor signal feedback control method as described above, the motor state feedback signal includes a power feedback signal, a speed feedback signal, a state feedback signal, a bus voltage feedback signal, a current feedback signal, a standby feedback signal and a torque feedback signal.

[0018] As described above, a PWM-based motor signal feedback control method, the motor state signal feedback frequency function module includes a speed feedback duty cycle function module, a power feedback duty cycle function module, a state feedback duty cycle function module and a shutdown function module; the motor state feedback signal decoding module includes a speed feedback signal decoding module, a power feedback signal decoding module and a state feedback signal decoding module.

[0019] In the PWM-based motor signal feedback control method as described above, the signal feedback circuit includes an optocoupler feedback circuit and / or a transistor feedback circuit.

[0020] A device uses the above-mentioned PWM-based motor signal feedback control method.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The motor of the present invention and the main control board are controlled by a signal feedback circuit and software logic to realize the function of multiple motor state signal feedback, so that the main control board can accurately adjust the target value of the motor in real time according to the multiple motor state feedback signals, and at the same time simplify the hardware structure of the main control board and the motor to reduce costs. The system analyzes the feedback signal based on the functional relationship and the fixed PWM parameter range and adjusts the working state of the motor accordingly, which helps to maintain the stable operation of the system and reduce the probability of abnormal situations. Due to the use of structured PWM parameter settings and function mapping relationships, when encountering problems, it is easier for technicians to locate the fault point and make necessary adjustments or repairs, thereby improving the maintainability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0024] Figure 1 is the optocoupler feedback circuit diagram of the present invention;

[0025] Figure 2 It is a triode feedback circuit diagram of the present invention;

[0026] Figure 3 The software of the present invention realizes the logic Figure 1 ;

[0027] Figure 4 The software of the present invention realizes the logic Figure 2 ;

[0028] Figure 5 The software of the present invention realizes the logic Figure 3 . DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings:

[0030] like Figures 1 to 5 The motor signal feedback control method based on PWM shown in the figure includes a signal feedback circuit arranged on the motor or connected to the motor so as to receive the motor feedback signal and output the control signal. The signal feedback circuit can be an optocoupler feedback circuit and / or a transistor feedback circuit. The method includes:

[0031] S1. Set the first functional relationship between N different motor state feedback signals and PWM duty cycle d in the main control board, and define a PWM duty cycle range for each first functional relationship, and the PWM duty cycle ranges do not overlap; set the second functional relationship between A different motor state feedback signals and PWM frequency f in the main control board, and define a PWM frequency f range for each second functional relationship, and the PWM frequency ranges do not overlap; set a transmission cycle of the motor, and divide the transmission cycle into M transmission cycle time periods, and set the motor to feedback the PWM duty cycle signals corresponding to different motor state feedback signals in different transmission cycle time periods, and the motor outputs the PWM duty cycle signals corresponding to each motor state feedback signal to the main control board according to the transmission cycle timing cycle. Wherein, N, M and A are all integers, and N>1, A>1, M≥N; the motor is a PSC motor or a PWM motor.

[0032] Preferably, M=N, and the length of each sending cycle time period in a sending cycle is the same; the motor state feedback signal includes a power feedback signal, a speed feedback signal, a state feedback signal, a bus voltage feedback signal, a current feedback signal, a standby feedback signal and a torque feedback signal.

[0033] S2, the motor outputs the PWM duty cycle signal and PWM frequency signal corresponding to each motor state feedback signal to the main control board;

[0034] S3. The main control board determines the type of motor state feedback signal according to the received PWM signal duty cycle range and PWM frequency range, and calculates the actual value of each motor state feedback signal according to the corresponding first functional relationship and second functional relationship. The main control board adjusts the motor target value according to the actual value of each motor state feedback signal.

[0035] Preferably, the motor target quantity is a rotation speed target quantity, a torque target quantity, or an air volume target quantity.

[0036] The above-mentioned signal feedback circuit and main control board can be arranged on the motor, or on a device such as an air conditioner.

[0037] In one implementation, the following takes the output of a power feedback signal, a speed feedback signal and a state feedback signal from a motor to a main control board through a signal feedback circuit as an application example, and the control method is as follows:

[0038] S10, establish a first functional relationship between the motor feedback signal and the PWM duty cycle d, so that the PWM signal duty cycle changes with the change of the motor signal value, and define the duty cycle range of the first functional relationship. The definitions are as follows:

[0039] Define the speed feedback PWM signal duty cycle d1 = d(RPM), and the range of d1 is (1%, 30%); define the power feedback PWM signal duty cycle d2 = d(HP), and the range of d2 is (30%, 60%); define the state feedback PWM signal duty cycle d3 = f(FO), and the range of d3 is (60%, 90%).

[0040] S20. After the PWM signals with different duty cycles are generated, the PWM signals are output to the main control board in a transmission cycle T as agreed. If three frequency signals, namely, power feedback signal, speed feedback signal and state feedback signal, are set in this application, a transmission cycle T can be set to 30S, and the three PWM signals can be set to be sent in the following timing cycle, that is, outputting power feedback PWM signal in 0-10S, outputting speed feedback PWM signal in 11-20S, and outputting state feedback PWM signal in 21-30S.

[0041] S30. After receiving the above three PWM signals, the main control board determines the corresponding motor state feedback signal type according to the agreed duty cycle range characteristics, and reversely calculates the actual value of the corresponding motor state feedback signal according to the corresponding first functional relationship. The main control board then accurately adjusts the motor target value based on these feedback actual values.

[0042] S100, establish a first functional relationship between the motor feedback signal and the PWM frequency f, so that the PWM signal frequency changes with the change of the motor signal value, and define the frequency range of the second functional relationship. The definitions are as follows:

[0043] Define the speed feedback PWM signal frequency f1 = f(RPM), and f1 = speed / 10, the range is (60hz, 200hz); define the power feedback PWM signal frequency f2 = f(HP), (1 / 3HP: 275hz, 1 / 2HP: 300hz, 3 / 4HP: 325hz, 1HP: 350hz); define the fault feedback PWM signal frequency f3 = f(FO), overvoltage: 400hz, undervoltage: 425hz, overcurrent: 450hz; standby feedback PWM signal frequency: f4 = f(STOP), f4 = 30hz.

[0044] S200, after the above PWM signals of different frequencies are generated, they are output to the main control board according to the agreed logic in combination with the gear position signal and the motor's own operating information.

[0045] S300: When the internally defined "fault" state is detected at any time, press f3 to output a PWM signal.

[0046] S400, after receiving these PWM signals, the main control board determines the corresponding motor state feedback signal type according to the agreed frequency range characteristics, and reversely calculates the actual value of the corresponding motor state feedback signal according to the corresponding second functional relationship. The main control board then accurately adjusts the motor target value based on these feedback actual values.

[0047] In this case, more duty cycle ranges, signal frequency ranges and corresponding functional relationships can be further defined in S10 and S100 according to the actual motor feedback signal type requirements. At the same time, in S20, the number of time periods of the sending cycle can be set according to the number of motor feedback signal types in S10.

[0048] In one embodiment, the motor is provided with a motor drive module for driving the motor to rotate, and a motor control module connected to the motor drive module to control the motor rotation and capable of initializing motor-related variables and extracting motor operating parameters. The motor control module is connected with a plurality of motor state signal feedback duty cycle function modules for converting corresponding motor-related operating parameters into corresponding motor state signal duty cycles, and a sending signal time counter for calculating the sending signal time; a first receiving signal module for receiving a PWM duty cycle signal and identifying a corresponding motor state feedback signal according to a duty cycle range is provided on the main control board, the first receiving signal module is connected with a plurality of motor state feedback signal decoding modules for calculating the actual value of the corresponding motor state feedback signal by using a first functional relationship corresponding to the motor state feedback signal type according to the PWM duty cycle signal, and the motor state signal feedback module is connected with a main control board control module capable of adjusting the motor target quantity according to the actual value of each motor state feedback signal.

[0049] The motor is also provided with a control signal analysis module and a fault detection interrupt module for analyzing the motor control signal. The control signal analysis module is connected to multiple motor state signal feedback frequency function modules that convert the corresponding motor control signal into the corresponding motor state signal frequency, and a sending signal time counter that calculates the sending signal time; the fault detection interrupt module is connected to multiple fault function modules that convert the corresponding motor fault signal into the corresponding motor fault signal frequency; the main control board is provided with a receiving signal module that receives the PWM frequency signal and identifies the corresponding motor state feedback signal according to the frequency range, the receiving signal module is connected to multiple motor state signal feedback modules that calculate the actual value of the corresponding motor state feedback signal through the second functional relationship of the corresponding motor state feedback signal type using the PWM frequency signal, and the main control board control module adjusts the motor target amount according to the actual value of each motor state feedback signal.

[0050] Preferably, the motor state signal feedback duty cycle function module includes a speed feedback duty cycle function module, a power feedback duty cycle function module, a state feedback duty cycle function module, a power function module, a speed function module, a fault function module and a shutdown function module; the motor state feedback signal decoding module includes a speed feedback signal decoding module, a power feedback signal decoding module and a state feedback signal decoding module, and the PWM duty cycle signal is a PWM duty cycle square wave signal; the PWM frequency signal is a PWM frequency square wave signal.

[0051] like Figure 3 In the software implementation logic, after the motor starts to rotate, the motor control module initializes the motor-related variables and extracts the corresponding motor motion parameters, and then sends the corresponding motor motion parameters to the speed feedback duty cycle function module, the power feedback duty cycle function module, and the state feedback duty cycle function module respectively; then, according to the calculation time of the sending signal time counter, the speed feedback duty cycle function module, the power feedback duty cycle function module, and the state feedback duty cycle function module send corresponding duty cycle signals to the signal feedback circuit in turn within one sending cycle, wherein the frequency signal range of the speed feedback duty cycle function module is (1%, 30%), the duty cycle signal range of the power feedback duty cycle function module is (30%, 60%), and the state feedback duty cycle function module The frequency signal range is (60%, 90%); then the signal feedback circuit converts each duty cycle signal into a corresponding PWM square wave duty cycle signal and sends it to the main control board; then the main board receiving signal module identifies the motor state feedback signal type corresponding to the PWM square wave duty cycle signal according to the agreed duty cycle signal range, and sends the corresponding PWM square wave duty cycle signal to the speed feedback signal decoding module, the power feedback signal decoding module or the state feedback signal decoding module according to the motor state feedback signal type; then each motor state feedback signal decoding module performs an inverse function calculation based on the corresponding first functional relationship to obtain the actual value of each motor state feedback signal; finally, the main control board control module adjusts the motor target according to the actual value of each motor state feedback signal. Among them, the inverse function calculation is based on the first functional relationship established between the motor state feedback signal and the PWM duty cycle d, and the actual value of the motor state feedback signal is calculated in reverse.

[0052] like Figure 4In the software implementation logic, after the motor starts to rotate, the control signal analysis module enters S101 to determine whether there is an idle / stop request. If yes, the control signal analysis module enters S102 to output the PWM signal according to f(HP). If no, the control signal enters S103 to determine whether there is a running signal. If there is a running signal, the control signal enters S105 to output the speed feedback PWM signal frequency; after S102, the control signal enters S104 to determine whether there is a running request. If yes, the control signal enters S105 to output the PWM signal according to f(RPM). If no, the control signal enters S106 to determine whether it exceeds 10S. If yes, the control signal enters S108 to output the PWM signal according to f(STOP). If no, the control signal returns to step S102; after S105, the control signal enters S107 to determine whether there is an idle / stop request again. If yes, the control signal enters S108 to output the PWM signal according to f(STOP), otherwise, the control signal returns to step S105.

[0053] like Figure 5 In the software implementation logic, after the motor starts to rotate, S201 the motor control module initializes the motor related variables, S202 inputs the control signal to the control signal parsing module, S203 determines whether the motor is in the running state or the shutdown state, when the motor is in the shutdown state, enters S204 the power function module receives the signal for processing, S205 outputs the PWM signal according to f(HP), S206 determines whether there is a mainboard operation request, when there is an operation request, enters S207 the speed function module receives the signal for processing, S208 outputs the PWM signal according to (RPM), S209 determines whether there is an idle / stop request, when there is an idle / stop request, enters S210 the shutdown function module receives the signal for processing, S211 outputs the PWM signal according to f(STOP), S212 determines whether there is a mainboard operation request, if there is a mainboard operation request, enters step S213, if not If yes, return to step S209; when S206 determines that there is no mainboard operation request, enter S222 to determine whether it exceeds 10S, if yes, enter S210, otherwise return to S204; when S203 determines that the motor is in operation, enter S213 to calculate the target speed / air volume / torque, calculate the actual value of the target speed / air volume / torque, S214 the motor drive module adjusts the motor target according to the actual value, S215 the motor state detection module detects the motor target, and then enters step S207; after step S201, it will enter step S216 the fault detection interrupt module for detection, S217 determines whether there is a fault, when there is no fault, S218 the motor runs normally; when S217 determines that there is a fault, S219 the motor stops running and outputting, S220 the fault function module receives the signal for processing, and S221 outputs the PWM signal according to f(ERROR).

[0054] The present application also discloses a device using the above control method, and the device may be a motor or an air conditioner or other electronic products or equipment.

[0055] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A motor signal feedback control method based on PWM, comprising a signal feedback circuit arranged on the motor or connected to the motor so as to receive the motor feedback signal and output a control signal, characterized in that: The method includes S1. A first functional relationship between N different motor state feedback signals and PWM duty cycle d is set in the main control board, and a PWM duty cycle range is defined for each first functional relationship, and the PWM duty cycle ranges do not overlap with each other; A second functional relationship between A different motor state feedback signals and PWM frequency f is set in the main control board, and a PWM frequency f range is defined for each second functional relationship, and the PWM frequency ranges do not overlap with each other; S2, the motor outputs the PWM duty cycle signal and PWM frequency signal corresponding to each motor state feedback signal to the main control board; S3. The main control board determines the type of motor state feedback signal according to the received PWM signal duty cycle range and PWM frequency range, and calculates the actual value of each motor state feedback signal according to the corresponding first functional relationship and second functional relationship. The main control board adjusts the motor target value according to the actual value of each motor state feedback signal.

2. The motor signal feedback control method based on PWM according to claim 1, characterized in that: In S1, a sending cycle of the motor is set, and the sending cycle is divided into M sending cycle time periods, and the motor is set to feedback PWM duty cycle signals corresponding to different motor state feedback signals in different sending cycle time periods. The motor outputs the PWM duty cycle signals corresponding to each motor state feedback signal to the main control board according to the sending cycle timing cycle.

3. The motor signal feedback control method based on PWM according to claim 2, characterized in that: In S1, N, M and A are all integers, and N>1, A>1, and M≥N.

4. The motor signal feedback control method based on PWM according to claim 1, characterized in that: The motor is provided with a motor drive module for driving the motor to rotate, and a motor control module connected to the motor drive module to control the motor rotation and capable of initializing motor-related variables and extracting motor operating parameters. The motor control module is connected with a plurality of motor state signal feedback duty cycle function modules for converting corresponding motor-related operating parameters into corresponding motor state signal duty cycles, and a sending signal time counter for calculating the sending signal time. The main control board is provided with a first receiving signal module for receiving a PWM duty cycle signal and identifying a corresponding motor state feedback signal according to a duty cycle range. The first receiving signal module is connected with a plurality of motor state feedback signal decoding modules for calculating the actual value of the corresponding motor state feedback signal through a first functional relationship corresponding to the motor state feedback signal type using the PWM duty cycle signal. The motor state signal feedback module is connected with a main control board control module capable of adjusting the motor target quantity according to the actual value of each motor state feedback signal.

5. A motor signal feedback control method based on PWM according to claim 3 or 4, characterized in that: The motor is provided with a control signal analysis module for analyzing the motor control signal, the control signal analysis module is connected to a plurality of motor state signal feedback frequency function modules for converting the corresponding motor control signal into the corresponding motor state signal frequency, and a sending signal time counter for calculating the sending signal time; the main control board is provided with a second receiving signal module for receiving the PWM frequency signal and identifying the corresponding motor state feedback signal according to the frequency range, the second receiving signal module is connected to a plurality of motor state signal feedback modules for calculating the actual value of the corresponding motor state feedback signal through the second functional relationship of the corresponding motor state feedback signal type according to the PWM frequency signal, and the motor state signal feedback module is connected to a main control board control module that can adjust the motor target amount according to the actual value of each motor state feedback signal.

6. The motor signal feedback control method based on PWM according to claim 5, characterized in that: The motor is also provided with a fault detection interrupt module for fault detection, and the fault detection interrupt module is connected to a plurality of fault function modules that convert corresponding motor fault signals into corresponding motor fault signal frequencies; the main control board is provided with a third receiving signal module that receives the motor fault signal frequency and identifies the motor fault feedback signal according to the frequency range, and the third receiving signal module is connected to a plurality of motor fault feedback modules that calculate the actual value of the corresponding motor fault feedback signal through the second functional relationship of the corresponding motor fault feedback signal type using the PWM frequency signal, and the main control board control module adjusts the motor target amount according to the actual value of each motor fault feedback signal.

7. The motor signal feedback control method based on PWM according to claim 6, characterized in that: The motor target quantity is a rotation speed target quantity, a torque target quantity, or a wind volume target quantity.

8. The motor signal feedback control method based on PWM according to claim 6, characterized in that: The motor state feedback signal includes a power feedback signal, a speed feedback signal, a state feedback signal, a bus voltage feedback signal, a current feedback signal, a standby feedback signal and a torque feedback signal; the motor state signal feedback frequency function module includes a speed feedback duty cycle function module, a power feedback duty cycle function module, a state feedback duty cycle function module and a shutdown function module; the motor state feedback signal decoding module includes a speed feedback signal decoding module, a power feedback signal decoding module and a state feedback signal decoding module.

9. The motor signal feedback control method based on PWM according to claim 1, characterized in that: The signal feedback circuit includes an optocoupler feedback circuit and / or a transistor feedback circuit.

10. A device, characterized in that: The device uses a PWM-based motor signal feedback control method as described in any one of claims 1-9.

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