METHOD FOR CONTROLLING THE OPERATION OF A PERMANENT MAGNET SYNCHRONOUS MOTOR BASED ON NON-INDUCTIVE VECTOR CONTROL

Abstract

A method for controlling the operation of a permanent magnet synchronous motor based on non-inductive vector control is provided, characterized in that: during motor operation, when a shutdown control signal is received from an external device, a microprocessor MCU does not directly execute the blocking PWM pulse in an inverter, but continues to send a pulse to the inverter to reduce speed and constantly detects the control signals sent by the external device;During speed reduction, when the real-time operating rotation speed Vi of the motor is greater than or equal to the set rotation speed Vref, the microprocessor MCU reacquires a new start control signal, then the control motor approaches the target rotation speed V or target torque T corresponding to the new start control signal reacquired from the current real-time operating rotation speed Vi;When the real-time operating rotation speed Vi of the motor is less than the set rotation speed Vref, the microprocessor's MCU executes PWM pulse blocking and turns off and blocks the pulses after the speed reduction, in such a way that the torque at a predetermined position of the motor can stably stop a load, thereby avoiding disturbances, vibrations, noise and the like, reducing the impact of the current and prolonging the life of the motor.

Description

METHOD FOR CONTROLLING THE OPERATION OF A PERMANENT MAGNET SYNCHRONOUS MOTOR BASED ON NON-INDUCTIVE VECTOR CONTROL Field of Invention The presentation refers to a method for controlling the operation of a permanent magnet synchronous motor through sensorless vector control. QQRP Ln / Cznz / B / YIAI Background of the Invention Permanent magnet synchronous motors with Hall sensors are capable of constantly detecting the rotor's position and speed, thus ensuring stable and reliable control of the entire process. However, the use of Hall sensors increases the motor's size and cost, and the wiring between them leads to interference, reducing motor performance. Furthermore, the precise installation of Hall sensors increases the complexity of motor manufacturing processes. Currently, many manufacturers are gradually promoting permanent magnet synchronous motors without Hall sensors to overcome the disadvantages of using them, thereby expanding the application range of permanent magnet synchronous motors. However, since the motor's rotor position is estimated using complex algorithms, the control algorithm requires high reliability. To improve starting torque, especially for large inertia loads, a commonly used method is pre-positioning. However, this method allows the permanent magnet synchronous motor to continue rotating for an extended period when the large inertia load receives a shutdown signal (intended to stop the permanent magnet synchronous motor) from an external source. If a run signal is restored during this period, the permanent magnet synchronous motor will restart while still rotating, which can result in overcurrent, vibration, noise, and other problems. - 2 abnormal situations. In extreme cases, it can even cause damage to the components. Currently, there are two methods to solve the problems: 1) wait for the load to stop completely before starting the permanent magnet synchronous motor; however, due to the high inertia of the load, this method is time-consuming, resulting in a poor user experience; 2) after the drive is switched off and the operating signal is received from the outside, the permanent magnet synchronous motor still needs to continue rotating due to the high inertia of the load. And if the permanent magnet synchronous motor is started according to the pre-positioning method when the rotation speed is high, it can produce a surge voltage that can damage the switching device.Furthermore, if the permanent magnet synchronous motor is started directly from the pre-positioning position while rotating at high speed, it can cause a large current surge, as well as jerking, vibration, noise, and other problems. This necessitates an additional hardware redundancy design, but the jerking, vibration, noise, and other issues cannot be completely resolved, and there is still a possibility of the permanent magnet synchronous motor failing to start. QQRP Ln / Cznz / B / YIAI Summary of the Invention One objective of this presentation is to provide a method for controlling the operation of a permanent magnet synchronous motor using sensorless vector control. This addresses the problem that, after the drive is switched off and the operating signal is received from an external source, the permanent magnet synchronous motor continues to rotate due to the high inertia of the load. Furthermore, if the permanent magnet synchronous motor is started using the pre-positioning method at high rotational speed, it can produce a surge voltage that may damage the switching device. Additionally, if the permanent magnet synchronous motor is started directly from the pre-positioning method while rotating at high speed, it can cause a -3 high current impact, as well as shocks, vibrations, noise and other problems. The method for controlling the operation of a permanent magnet synchronous motor by means of sensorless vector control comprises: during the operation of the permanent magnet synchronous motor, receiving, by the permanent magnet synchronous motor, a shutdown signal from an external device; continuously emitting, by means of a microcontroller unit (MCU), a deceleration pulse to an inverter, instead of directly blocking a PWM (Pulse Width Modulation) pulse to the inverter, and constantly monitoring a control signal sent by the external device;During a deceleration process, when the MCU receives a new start signal and the real-time speed Vi of the permanent magnet synchronous motor is greater than or equal to the reference speed Vref, the MCU controls the permanent magnet synchronous motor to rotate with a parameter that approximates a target torque Toa at a target speed V corresponding to the new start signal from the real-time speed Vi; and blocks, by means of the MCU, the PWM pulse when the real-time speed Vi of the permanent magnet synchronous motor is less than the reference speed Vref. In a class of this type, when the MCU blocks the PWM pulse, the permanent magnet synchronous motor continues to rotate due to inertia, and the control signal sent by the external device is constantly monitored; if, at this stage, the MCU receives another new start signal, all the switching transistors of the lower bridge are activated, causing the permanent magnet synchronous motor to enter a dynamic braking mode for a duration ti; the MCU gives commands to introduce currents into the phase windings sequentially to lock the rotor position for a duration t2; and the permanent magnet synchronous motor re-enters a sensorless start state according to the new start signal. In a class of this type, the synchronous magnet motor QQRP Ln / Cznz / B / YIAI -4permanent is a three-phase permanent magnet synchronous motor with a three-phase winding comprising three sets of coils U, V, W; when the MCU blocks the PWM pulse and the MCU receives the new start signal, three lower bridge switching transistors Q4, Q5 and Q6 are activated, causing the motor to enter dynamic braking mode for the duration ti; and the MCU gives commands to introduce currents to the three sets of coils U, V and W sequentially to lock the rotor position for the duration t2. In a class of this mode, when the motor receives a shutdown signal from the outside, the MCU controls the motor to decelerate; when the shutdown signal exceeds or is equal to the set time duration t3, the MCU blocks the PWM pulses. In a class of this type, the reference speed Vref is in the range of 200 to 400 rpm. In a class of this type, the permanent magnet synchronous motor rotates at the parameter that approximates the target speed V corresponding to the new real-time speed start signal Vi with a progressive step V0 increasing or decreasing. In a class of this modality, the progressive step V0 is determined based on rotational inertia and the difference between the real-time speed Vi and the target speed V corresponds to the acquired take-off position signal. The following advantages are associated with exposure: 1) The permanent magnet synchronous motor receives a shutdown signal from an external device during operation; instead of directly blocking a PWM pulse to the inverter, the MCU continues to generate a deceleration pulse to an inverter and constantly monitors the control signal sent by the external device; during the deceleration process, when the real-time speed Vi of the motor is greater than or equal to the reference speed Vref, and the MCU receives a new start signal, the permanent magnet synchronous motor is controlled to rotate with a parameter close to a torque QQRP Ln / Cznz / B / YIAI The MCU sets a target speed V corresponding to the new start signal from a real-time speed Vi. When the real-time speed Vi of the permanent magnet synchronous motor is less than the reference speed Vref, the MCU blocks the PWM pulses. In applications with high-inertia loads, this method allows the permanent magnet synchronous motor to respond quickly and smoothly during tap position signal recovery, frequent start-stop cycles, and tap position changes, thus preventing problems such as jerking, vibration, and noise. 2) The other advantages of the exhibition are described in detail in the modalities. Brief Description of the Figures of the Invention Figure 1 is a perspective view of a permanent magnet synchronous motor according to Example 1 of the exhibit; Figure 2 is a perspective view of a motor controller for a permanent magnet synchronous motor according to Example 1 of the exhibit; Figure 3 is a cross-sectional view of a permanent magnet synchronous motor according to Example 1 of the exhibit; Figure 4 is a schematic diagram illustrating the control principle of a motor controller according to Example 1 of the exposition; Figure 5 is a schematic diagram illustrating a sensorless vector control principle of a permanent magnet synchronous motor according to Example 1 of the exhibit; Figure 6 is a diagram showing the relationship of the coordinate system for the vector control of a permanent magnet synchronous motor according to Example 1 of the exposition; Figure 7 is a block diagram illustrating the principle of a motor controller according to Example 1 of the exhibit; Figure 8 is a flowchart illustrating a control process QQRP Ln / Cznz / B / YIAI -6 of a permanent magnet synchronous motor according to Example 1 of the exhibit; Figure 9 is a schematic diagram illustrating the connection between the permanent magnet synchronous motor and an external device according to Example 1 of the exhibit; Figure 10 is a flowchart illustrating a control method for controlling the operation of a permanent magnet synchronous motor based on sensorless vector control according to Example 1 of the exposition; Figure 11 is a flowchart illustrating a reacquisition control process of a new start signal during the PWM pulse blocking process according to Example 1 of the exposition; Figure 12 is a schematic diagram illustrating the connection between the permanent magnet synchronous motor and an external device drive according to Example 2 of the exposition; and Figure 13 is a circuit block diagram of a motor controller according to Example 2 of the exhibit. Detailed Description of the Invention To better illustrate the discussion, the following modalities detail a method for controlling the operation of a permanent magnet synchronous motor using sensorless vector control. It should be noted that the following modalities are intended to describe, not to limit, the discussion. QQRP Ln / Cznz / B / YIAI Example 1 As shown in Figures 1-3, a three-phase permanent magnet synchronous motor comprises a motor controller 2 and a motor body 1. The motor body 1 comprises a stator assembly 12, a rotor assembly 13, and a housing assembly 11. The stator assembly 13 is arranged in the housing assembly 11, and the assembly of The rotor 13 is located inside or outside the stator assembly 12. The motor controller 2 comprises a control box 22 and a control circuit board 21 located within the control box 22. The control circuit board 21 comprises a power supply circuit, a microcontroller unit (MCU), a bus voltage sensing circuit, and an inverter. The power supply circuit is configured to provide electrical power to each part of the circuit. The bus voltage sensing circuit is configured to input the DC bus voltage Uabc to the MCU. The MCU is configured to control the inverter. The inverter is configured to manage the switching state of the phase winding of the stator assembly 12. The stator assembly 12 comprises a stator core and a three-phase winding. The three-phase winding comprises three sets of coils U, V, and W. The three-phase permanent magnet synchronous motor further comprises a phase current sensing circuit configured to input two-phase currents ia and ib from three coil sets to the MCU. Based on the relationship between the three-phase currents ia, ib, and ic, the phase current ic can be calculated, and the MCU can calculate the current iq of shaft q. These calculations are already described in textbooks and will not be repeated here. A full-wave rectifier circuit comprises diodes D7, D8, D9, and DIO, which are configured to convert the input AC voltage to a DC bus voltage Vbus. The DC bus voltage Vbus is output from one end of capacitor C1 and is relative to the input AC voltage. The MCU is configured to send the PWM signal to the inverter. The inverter comprises six electronic switching transistors Q1, Q2, Q3, Q4, Q5, and Q6, each of which includes a control terminal.The six control terminals are regulated by six PWM pulse signals (P1, P2, P3, P4, P5, and P6) emitted from the MCU, respectively. The electronic switching transistors Q1, Q2, Q3, Q4, Q5, and Q6 are divided into two sets: a set of three upper bridge switching transistors Q1, Q2, and Q3, and a set of three lower bridge switching transistors Q4, Q5, and Q6. QQRP Ln / Cznz / B / YIAI -8As shown in Figure 4, the MCU comprises a plurality of tap position input signals Tap1, Tap2... Tapn, where n is an integer. Each tap position input signal is connected to a tap position detection circuit via a switch. The MCU uses several tap position detection circuits to detect the corresponding tap position input signals. The tap position input signals Tap1, Tap2... Tapn correspond to switches K1, K2... Kn, respectively. For example, when switch K1 is closed, the corresponding tap position input signal Tap1 is detected by the connected tap position detection circuit and sent to the MCU, which then controls the motor to operate at a preset speed.For example, the Tap1 tap position input signal corresponds to a motor speed of 700 rpm, the Tap2 tap position input signal corresponds to 800 rpm, the Tap3 tap position input signal corresponds to 900 rpm, and the Tapn tap position input signal corresponds to 1400 rpm. The MCU controls the motor to operate at a specific speed corresponding to the tap position input signal received. When the MCU does not receive any of the tap position input signals (i.e., when all switches are open), the MCU blocks the PWM signal output, resulting in the deactivation of the electronic switch transistors Q1, Q2, Q3, Q4, Q5, and P6. This state is commonly known in the industry as pulse-block shutdown. When all switches K1, K2... Kn are open, all tap position input signals Tap1, Tap2... Tapn are disconnected from the MCU. In this situation, the tap position input signals can be referred to as shutdown signals sent by the external device. However, when one of the switches K1, K2... Kn is closed, the corresponding tap position input signal Tap1, Tap2... Tapn is fed into the MCU. As shown in Figure 5, a principle is briefly described. QQRP Ln / Cznz / B / YIAI -9 Basic operation of a permanent magnet synchronous motor based on sensorless vector control (detailed descriptions can be found in textbooks). The permanent magnet synchronous motor operates based on the interaction between the rotating magnetic field of the stator and the rotating magnetic field of the rotor. Figure 5 illustrates two coordinate systems: a dq coordinate system representing the rotating coordinate system of the rotor and a stationary ABC coordinate system of the stator. The stationary ABC coordinate system can be transformed into the αβ coordinate system, which consists of two coordinate axes, the axes and the βxes. The axes and the βxes are perpendicular to each other, as illustrated in Figure 6. The rotor can be understood to rotate at a speed wr as a result of the excitation current is, while the stator can be understood to rotate at a speed ws due to the excitation current is.As shown in Figure 5, the stator composite vector is denoted by S. The electromagnetic torque is calculated using the formula:. T = K x iq where T is the electromagnetic torque, K is the coefficient and iq is the current component of the q-axis of the composite vector S. As shown in Figure 6, the stationary ABC coordinate system is replaced by the αβ coordinate system. The αβ coordinate system represents the stationary stator coordinate system, and the dq coordinate system represents the rotating rotor coordinate system. The angle between the αβ coordinate system and the dq coordinate system is denoted as Θ. Figure 7 is a block diagram illustrating the hardware control of the permanent magnet synchronous motor. Figure 8 is a block diagram illustrating the software control of the permanent magnet synchronous motor based on sensorless vector control. The MCU calculates the current iq of shaft q and the current id of shaft d based on the phase currents ia, ib, and ic. The real-time speed Vi of the motor is estimated using a position and velocity observer. QQRP Ln / Cznz / B / YIAI - 10 Assuming a desired speed Vsp is selected via the acquired tap position input signal, the MCU controls the motor to operate at the desired speed (Vsp). When the motor's real-time speed Vi does not reach the selected speed Vsp, the torque iq_in is adjusted until the real-time speed Vi aligns with the selected speed Vsp. As shown in Figures 9, 10, and 11, a method for controlling the operation of a permanent magnet synchronous motor by sensorless vector control comprises the following steps: the permanent magnet synchronous motor receives a shutdown signal from an external device during operation; instead of directly blocking a PWM pulse to the inverter, the MCU continues to generate a deceleration pulse to an inverter and constantly monitors a control signal sent by the external device; during the deceleration process, when the real-time speed Vi of the motor is greater than or equal to the reference speed Vref, and the MCU receives a new start signal, the permanent magnet synchronous motor is controlled to rotate with a parameter close to a target torque T or a target speed V corresponding to the new start signal;When the real-time speed Vi of the permanent magnet synchronous motor is less than the reference speed Vref, the MCU blocks the PWM pulses. When the MCU blocks the PWM pulses, the permanent magnet synchronous motor continues to rotate due to inertia, and the external control signal is constantly monitored. If, at this stage, the MCU receives a new start signal, all the transistors in the lower bridge switch are activated, causing the monitor to enter a dynamic braking mode for a duration t1. Subsequently, the MCU commands to sequentially introduce currents into the phase windings to lock the rotor position for a duration t2. The permanent magnet synchronous motor then re-enters a sensorless start state in accordance with the new start signal. QQRP Ln / Cznz / B / YIAI - 11 The permanent magnet synchronous motor is a three-phase permanent magnet synchronous motor with a three-phase winding comprising three sets of coils U, V, and W. During the PWM pulse-blocking process, when the MCU receives a new start signal, the three lower bridge-switching transistors Q4, Q5, and Q6 are activated, causing the motor to enter dynamic braking mode for a duration ti (e.g., 1 second). Subsequently, the MCU commands to introduce currents into the three sets of coils U, V, and W sequentially to lock the rotor position for a duration t2 (e.g., 2 seconds). When the motor receives a shutdown signal from an external source, the MCU controls the motor to decelerate. When the shutdown signal exceeds or equals a set duration t3 (e.g., 3 seconds), the MCU strongly blocks the PWM pulses. The reference speed Vref is in the range of 200 to 400 rpm. Specifically, the reference speed Vref is 300 rpm. When all tap position signals are removed (i.e., all switches K1, K2...Kn are open, and all tap position input signals Tap1, Tap2...Tapn are disconnected from the MCU), the MCU continues to send pulses to the inverter for deceleration. When the real-time speed Vi is lower than the reference speed Vref (e.g., Vref = 300 rpm), the MCU blocks the PWM pulses, effectively stopping the motor at low speeds. This method exhibits a fast response and adaptability to large inertial loads, ensuring a high-quality user experience. Despite the significant load inertia, torque at speeds of 300 rpm and below is sufficient to stop inertial loads without causing anomalies such as jerking or noise. At this stage, the starting process shares the same logic as a normal stationary start, ensuring a smooth start.During the PWM pulse blocking process, even if a new tap position signal is received (i.e., when one of the switches K1, K2...Kn closes and one of the... QQRP Ln / Cznz / B / YIAI - Twelve tap position input signals (Tap1, Tap2...Tapn) are provided as input to the MCU, effectively giving the MCU a new start signal. The new tap position signal is not processed until the motor has completely stopped. Subsequently, the motor restarts based on the new tap position signal. However, during the deceleration process, if the real-time speed Vi reaches or exceeds the set speed Vref, and the MCU acquires a new tap position signal, the motor gradually runs from the real-time speed Vi to the target speed V corresponding to the new tap position signal. This method eliminates the need for the traditional method of switching the motor's tap position for pre-positioning during high-speed rotation, thus avoiding problems such as jerking, vibration, and noise, and reducing the impact on current.The commutators are effectively protected, extending the service life of the permanent magnet synchronous motor. In applications with high inertia loads, this method allows the permanent magnet synchronous motor to respond quickly and smoothly during tap position signal recovery, frequent start-stop cycles, and tap position changes, thus preventing problems such as jerking, vibration, and noise. By incrementally adjusting the real-time speed Vi with a progressive step VO toward the target speed V, the real-time speed Vi is adjusted to approximate the target speed V corresponding to the new PTO position signal. Specifically, when the real-time speed Vi is greater than the target speed V corresponding to the new PTO position signal, the motor decelerates with a progressive step VO toward speed V. Conversely, when the real-time speed Vi is less than the target speed V, the motor accelerates with a progressive step VO to approach the target speed V. The five PTO position input signals in Table 1 can be interpreted as new start signals. Table 1 Input signals for PTO position and motor speeds QQRP Ln / Cznz / B / YIAI - 13 corresponding Input signals for tap position speed (rpm) Tap position input Tap1 600 Tap position input Tap2 750 Tap position input Tap3 900 Tap position input Tap4 1000 Tap position input Tap5 1150 For example, assume a permanent magnet synchronous motor has five tap positions: Tap1, Tap2, Tap3, Tap4, and Tap5. The corresponding speed for each tap position is shown in Table 1. The MCU is connected to five tap position detection circuits, as shown in Figure 4. The MCU continuously monitors the tap position input signals from these five circuits. When the motor is operating in the tap position, the corresponding motor speed for tap position input signal Tap3 is 900 rpm. When tap position input signal Tap3 is removed, the motor speed gradually decreases from 900 rpm to 300 rpm. During this deceleration process, if the MCU does not receive the corresponding tap position input signal, the motor speed continues to decrease until it reaches 300 rpm.At this point, the MCU blocks the PWM pulses, causing the motor to stop immediately. However, if the MCU receives a new TDC position signal during the PWM pulse blocking process, even with a significant inertial load, the torque at speeds of 300 rpm and below is sufficient to stop the load without issues such as jerking or noise. In such cases, the starting process follows the same logic as a normal stationary start, ensuring a smooth start. If the MCU recovers the Tapl position input signal after the motor has stopped, the motor restarts using the default positioning method. Upon restart, the motor speed gradually increases and stabilizes at 600 rpm. When the motor is running in the 3rd PTO position, the speed The input signal for the Tap position signal 14 is 900 rpm. When the Tap position input signal 3 is removed, the engine speed gradually decreases from 900 rpm to 300 rpm. Assuming that when the engine speed drops to 800 rpm, the Tap position input signal 11 is received. Since the Tap position input signal 11 corresponds to an engine speed of 600 rpm, which is lower than the current speed of 800 rpm, the engine continues to decelerate until it reaches a stable speed of 600 rpm. When the motor is operating in the third PTO position, the corresponding speed for the Tap3 PTO position input signal is 900 rpm. When the Tap3 PTO position input signal is removed, the motor speed gradually decreases from 900 rpm to 300 rpm. Assuming that when the motor speed drops to 800 rpm, the Tap5 PTO position input signal is received. Since the Tap5 PTO position input signal corresponds to a motor speed of 1150 rpm, which is higher than the current speed of 800 rpm, the motor accelerates until it reaches a stable speed of 1150 rpm. By employing this method, during the deceleration of the permanent magnet synchronous motor, if the tap position signal is restored, the MCU adjusts the motor speed accordingly. This method allows the permanent magnet synchronous motor to respond quickly and restart smoothly in situations such as signal recovery, frequent start-stop cycles, and tap position changes. It prevents problems such as jerking, vibration, and noise, reduces current impact, effectively protects the commutators, extends the service life of the permanent magnet synchronous motor, and improves the user experience. The progressive step V0 is determined based on rotational inertia and the difference between the real-time speed Vi and the target speed V corresponding to the acquired position signal. Specifically, V0 = K* (Vi - V) / G, where K is a coefficient that QQRP Ln / Cznz / B / YIAI The coefficient K can be experimentally determined, Vi is the real-time speed, V is the target speed corresponding to the acquired tap position signal, and G is the rotational inertia of the motor. The K coefficient is determined experimentally, and the step value V0 is determined based on the actual values ​​of the rotational inertia G, the real-time speed Vi, and the target speed V. Therefore, the step VO is automatically adjusted to an appropriate value, allowing the permanent magnet synchronous motor to match the adjusted step VO for acceleration or deceleration. Consequently, the motor can respond quickly and restart smoothly in scenarios such as signal recovery, frequent start-stop cycles, and tap position changes, effectively improving the restart success rate of the permanent magnet synchronous motor. Assuming a progressive step VO of 10 revolutions per second, the motor progressively increases or decreases its real-time speed Vi by 10 revolutions per second, to achieve acceleration or deceleration towards the target speed V. When all take-off position signals are removed, the MCU continues sending pulses to the inverter for deceleration. Specifically, for deceleration, the step rate VIO is determined based on the difference between the real-time speed Vi and the reference speed Vref. The step rate is calculated as VIO = (Vi - Vref) / T, where T is a predetermined time. The deceleration process involves gradually reducing the motor speed from the real-time speed Vi to the reference speed Vref using the incremental step V0. This process continues until the real-time speed Vi falls below the reference speed Vref. At this point, the MCU blocks the PWM pulses. In this example, the reference speed Vref is determined experimentally, while the real-time speed Vi is measured by a speed observer. QQRPLn / CZnZ / B / Y Example 2 - 16 This example presents an improvement over Example 1, focusing on the use of a Variable Speed ​​Potentiometer (VSP) circuit as a replacement for the plurality of tap position sensing circuits and optocouplers. As shown in Figures 12 and 13, an external device sends a VSP signal to the permanent magnet synchronous motor based on sensorless vector control. The VSP signal ranges from 0 to 10 VDC, and the VSP signal types are described in Table 2. When the VSP signal reaches 0 V, it functions as a shutdown signal. During motor operation, when the permanent magnet synchronous motor receives the shutdown signal from the outside, the MCU does not immediately block the PWM pulses to the inverter. Instead, the MCU continues sending pulses to the inverter to slow it down while constantly monitoring the control signals received from the outside.During the deceleration process, when the real-time speed Vi is greater than or equal to the reference speed Vref, and the MCU receives a new start signal, the motor operates at approximately the target torque Toa and the target speed V corresponding to the new start signal. However, when the real-time speed Vi falls below the reference speed Vref, the MCU blocks the PWM pulses. Several types of new start signals are provided, including a 0.5 V–2 V signal, a 2 V–4 V signal, a 4 V–6 V signal, a 6 V–8 V signal, and an 8 V–10 V signal. QQRP Ln / Cznz / B / YIAI Table 2 Various types of new start signals 0-10 VDC VSP Signal (Voltage Signal) Speed ​​(rpm) Signal Type OV 0 Off Signal 0.5V-2V 600 Start Signal 2V-4V 750 Start Signal 4V-6V 900 Start Signal 6V-8V 1000 Start Signal 8V-10V 1150 Start Signal Similarly, a VSP circuit is used to select the pair - 17. Motor operation, as shown in Table 3. For example, when the VSP signal is 0 V, it functions as a shutdown signal. During motor operation, when the motor receives a shutdown signal from the outside, the MCU does not immediately block the PWM pulses to the inverter. Instead, the MCU continues sending pulses to the inverter to decelerate while constantly monitoring the control signals received from the outside. During the deceleration process, if the motor's real-time operating speed Vi is greater than or equal to the reference speed Vref, and the microcontroller's MCU acquires a new start signal, the motor operates to approach the target torque T corresponding to the newly acquired start signal. However, when the real-time speed Vi is less than the reference speed Vref, the MCU blocks the PWM pulses.Several new starting signals are provided for torque selection. For example, the 0.5 V - 2 V signal corresponds to a torque of 20 Nm, the 2 V - 4 V signal corresponds to a torque of 40 Nm, the 4 V - 6 V signal corresponds to a torque of 60 Nm, the 6 V - 8 V ​​signal corresponds to a torque of 80 Nm, and the 8 V - 10 V signal corresponds to a torque of 100 Nm. When the VSP signal is a start signal in the 2V–4V range, the motor operates at a torque of 40 Nm. While the motor is running, if the VSP signal drops to 0V, it acts as a stop signal. Instead of directly blocking the PWM pulses to the inverter, the MCU continues sending pulses to the inverter for deceleration. During the deceleration process, when the real-time speed Vi is greater than or equal to the reference speed Vref, and the MCU receives a new start signal (e.g., a new VSP start signal in the 4V–6V range), the motor operates at a torque of 60 Nm. Further details regarding other control aspects are not provided herein. QQRP Ln / Cznz / B / YIAI - 18 Table 3 Various types of new start signals Signal 0-10 VDC VSP (Voltage Signal) Torque (N / m) Signal Type OV 0 Off Signal 0.5V-2V 20 Start Signal 2V-4V 40 Start Signal 4V-6V 60 Start Signal 6V-8V 80 Start Signal 8V-10V 100 Start Signal QQRP Ln / Cznz / B / YIAI Furthermore, when an external device controls the sensorless vector-controlled permanent magnet synchronous motor using PWM signals, the principle is similar to that of the VSP signal, as shown in Table 4. A detailed description is not provided herein. Table 4 Various types of new start signals PWM Signal Torque (N / m) Signal Type OV 0 Off signal 10 pulses 20 Start signal 20 pulses 40 Start signal 30 pulses 60 Start signal 40 pulses 80 Start signal 50 pulses 100 Start signal It will be obvious to those skilled in the art that changes and modifications may be made, and therefore the objective of the appended claims is to cover all such changes and modifications.

Claims

1. A method for controlling the operation of a permanent magnet synchronous motor by sensorless vector control, the method comprising: during the operation of the permanent magnet synchronous motor, receiving, by means of the permanent magnet synchronous motor, a shutdown signal from an external device; continuously emitting, by means of a microcontroller unit (MCU), a deceleration pulse to an inverter, instead of directly blocking a PWM pulse to the inverter, and constantly monitoring a control signal sent by the external device;During a deceleration process, when the MCU receives a new start signal and the real-time speed Vi of the permanent magnet synchronous motor is greater than or equal to the reference speed Vref, control the permanent magnet synchronous motor to rotate at a parameter close to a target torque T or a target speed V corresponding to the new start signal from the real-time speed Vi; and block, by means of the MCU, the PWM pulse when the real-time speed Vi of the permanent magnet synchronous motor is less than the reference speed Vref.

2. The method of claim 1, wherein when the MCU blocks the PWM pulse, the permanent magnet synchronous motor continues to rotate due to inertia and the control signal sent by the external device is constantly monitored; if, at this stage, the MCU receives another new start signal, all the switching transistors of the lower bridge are activated, causing the permanent magnet synchronous motor to enter a dynamic braking mode for a duration ti; the MCU gives commands to introduce currents into the phase windings sequentially to lock the rotor position for a duration t2; and the permanent magnet synchronous motor re-enters a sensorless start state -20 in accordance with the new start signal.

3. The method of claim 2, wherein the permanent magnet synchronous motor is a three-phase permanent magnet synchronous motor with a three-phase winding comprising three sets of coils U, V, W; when the MCU blocks the PWM pulse and the MCU receives the new start signal, three lower bridge switching transistors Q4, Q5, and Q6 are activated, causing the permanent magnet synchronous motor to enter dynamic braking mode for the duration t1; and the MCU gives commands to introduce currents to the three sets of coils U, V, and W sequentially to lock the rotor position for the duration t2.

4. The method of claim 1, wherein when the motor receives a shutdown signal from the outside, the MCU controls the motor to decelerate; when the shutdown signal exceeds or is equal to the set time duration t3, the MCU blocks the PWM pulses.

5. The method of claim 1, 2, 3 or 4, wherein the reference speed Vref is in the range of 200 to 400 rpm.

6. The method of claim 1, 2 or 3, wherein the permanent magnet synchronous motor rotates at the parameter that approximates the target speed V corresponding to the new real-time speed start signal Vi with a progressively increasing or decreasing step V0.

7. The method of claim 4, wherein the progressive step V0 is determined based on the rotational inertia and the difference between the real-time speed Vi and the target speed V corresponding to an acquired takeoff position signal.

Images