CN101499754B - Double salient motor system for non-position sensor and control method thereof - Google Patents

Abstract

The invention discloses a position sensorless double salient motor system and a control method thereof, belonging to a double salient motor system and a control method thereof. The system of the present invention consists of a doubly salient pole motor, an excitation winding, a main power circuit and a control circuit, wherein the main power circuit includes a power supply and an IPM, and the control circuit includes an isolation circuit, a fault detection circuit, a three-phase current sampling circuit, and an excitation current sampling circuit. circuit, PWM control circuit, overcurrent and overvoltage protection circuit, ADC module, position detection circuit, speed calculation circuit, logic control circuit, capture unit, speed loop, current loop, hysteresis comparator and PI regulator. The control method of the present invention adopts a dual-loop control mode of current inner loop and rotational speed outer loop, and indirectly controls the current of the doubly salient motor by comparing the given rotational speed with the actual rotational speed fed back. The invention has the advantages of simple system, stronger structure, reliable operation and high efficiency.

Description

Position sensorless doubly salient motor system and its control method

technical field

The invention relates to a doubly salient motor system and a control method thereof, in particular to a position sensorless doubly salient motor system and a control method thereof.

Background technique

For the electrically excited doubly salient motor drive system, real-time and accurate rotor position information is a necessary prerequisite for its reliable operation. Obtaining position information by using shaft position sensors or other types of detection position detectors will not only increase the size of the motor, increase the cost and complexity of the system, but more importantly, reduce the robustness of the system structure and affect the reliable operation of the entire system . Therefore, how to remove the position detector and directly use the voltage and current information of the motor to indirectly determine the rotor position, so as to make the system structure stronger, the operation more reliable, efficient, and lower cost, is undoubtedly a very potential research direction. Aerospace, wind power fields are of great value. So far, research in this field at home and abroad is still in its infancy, and the research objects are mostly focused on the position sensorless switched reluctance motor with similar motor structure. There are two research ideas: (1) Pulse injection positioning method-although the algorithm of the pulse injection method is relatively simple, it inevitably has an inherent speed limit based on the input of high-frequency pulses, and the test current may bring Negative torque, its impact on the output and efficiency of the entire system is also a great deficiency; (2) Back EMF method--this method requires auxiliary starting facilities, phase compensation, and the matching of the count value speed current limit question. Because of the existence of these shortcomings, none of the above methods can be well realized in the end. Therefore, how to accurately obtain the rotor position angle information in real time has always been a difficult problem in the doubly salient position sensorless technology. At present, there is no effective method for position sensorless control of doubly salient motors at home and abroad.

Contents of the invention

The technical problem to be solved by the present invention is to propose a position sensorless double salient motor system and its control method for the defects of the prior art.

The sensorless doubly salient motor system of the present invention is composed of a doubly salient motor, an excitation winding, a main power circuit and a control circuit, wherein the main power circuit includes a power supply and an IPM, and the two output terminals of the power supply are connected to the two input terminals of the IPM respectively. The three output terminals of the IPM are respectively connected to the three input terminals of the doubly salient pole motor, and the output terminals of the doubly salient pole motor are connected to the input terminals of the excitation winding. The control circuit includes an isolation circuit, a fault detection circuit, three Phase current sampling circuit, excitation current sampling circuit, PWM control circuit, overcurrent and overvoltage protection circuit, ADC module, position detection circuit, speed calculation circuit, logic control circuit, capture unit, speed loop, current loop, hysteresis comparator and PI regulator, wherein the input terminal of the fault detection circuit is connected to the output terminal of the IPM, the output terminal of the fault detection circuit is connected to the input terminal of the overcurrent and overvoltage protection circuit, and the output terminal of the overcurrent and overvoltage protection circuit is connected to the input of the logic control circuit terminal; the three input terminals of the three-phase current sampling circuit are respectively connected to the three output terminals of the IPM, the output terminal of the three-phase current sampling circuit is connected to the input terminal of the ADC module, and the output terminal of the ADC module is connected to the negative input terminal of the current loop Connection; the input end of the excitation current sampling circuit is connected with the output end of the excitation winding, the output end of the excitation current sampling circuit is connected with the input end of the position detection circuit, one output end of the position detection circuit is connected with the input end of the capture unit, and the capture unit The output end of the position detection circuit is connected with the input end of the logic control circuit, the other output end of the position detection circuit is connected with the input end of the speed calculation circuit, the output end of the speed calculation circuit is connected with the negative input end of the speed loop; the output end of the speed loop is connected with the negative input end of the speed loop The input terminal of the PI regulator is connected, the output terminal of the PI regulator is connected to the positive input terminal of the current loop, the output terminal of the current loop is connected to the input terminal of the logic control circuit, and the output terminal of the logic control circuit is sequentially passed through the PWM control circuit, isolated The circuit is connected to the input of the IPM.

The control method of the position sensorless doubly salient motor system is to use the power supply to drive the doubly salient motor through the IPM, use the excitation current sampling circuit to sample the output excitation current if of the excitation winding, the excitation current sampling circuit outputs the pulse position signal, and sample the excitation current The output pulse position signal of the circuit passes through the position detection circuit and the speed calculation circuit in turn to obtain the actual speed ω _m of the doubly salient motor, and the output excitation current of the excitation winding passes through the position detection circuit and the capture unit in turn to obtain the trigger signal; a three-phase current sampling circuit is adopted Collect the three-phase input current of the doubly salient motor, pass the collected three-phase input current of the doubly salient motor through the ADC module to obtain the phase current i _P , and compare the actual speed ω _m of the doubly salient motor with the given doubly salient The real-time speed difference of the doubly salient pole motor is obtained through the speed loop ω _m ^* , and the given phase current i _P ^* is obtained by passing the real-time speed difference of the doubly salient pole motor through the PI regulator, and the given The phase current _iP ^* and the phase current _iP pass through the current loop to obtain the real-time current difference, and pass the real-time current difference through the hysteresis comparator to obtain a step signal; use the fault detection circuit to detect the IPM to obtain the fault signal of the doubly salient motor, and the The fault signal of the doubly salient motor passes through the overcurrent and overvoltage protection circuit to obtain high and low level signals; the trigger signal, step signal, and high and low level signals are passed through the logic control circuit to obtain the excitation signal, and the excitation signal is passed through the isolation circuit to obtain the IPM The driving signal is used to control the driving voltage and driving current output by the IPM, that is, the three-phase input current of the doubly salient motor.

The doubly salient motor of the present invention has a simple structure and large output, so the wind turbine simulator using the doubly salient motor can simplify the structure of the simulation system and reduce the cost when carrying out high-power or high-power simulation experiments. The invention can simulate various wind speed models under wind tunnel or wind field conditions by using artificial wind speed setting, has great flexibility, saves research funds for wind tunnel experiments, and shortens the research cycle of wind power generation technology. The invention utilizes the wind speed and rotational speed to obtain the characteristics of the wind turbine, which is used to control the given torque of the simulator, and uses the torque inner ring to realize the simulation of the wind turbine, which saves the research time for the early design of the wind turbine and brings great benefits. convenient.

Description of drawings

Fig. 1: block diagram of the control system of the present invention;

Figure 2: Waveform diagram of the three-phase mutual inductance and excitation current of the doubly salient motor of the present invention;

Figure 3: Sampling and conditioning circuit diagram of the excitation current of the doubly salient motor of the present invention;

Fig. 4: Waveform diagram of excitation current and position signal of the doubly salient motor of the present invention;

Fig. 5: The position signal and three-phase current waveform diagram of the doubly salient motor of the present invention.

Detailed ways

As shown in Figure 1. A sensorless doubly salient motor system consisting of a doubly salient motor, an excitation winding, a main power circuit and a control circuit, wherein the main power circuit includes a power supply and an IPM, and the two output ends of the power supply are respectively connected to the two inputs of the IPM The three output terminals of the IPM are respectively connected to the three input terminals of the doubly salient pole motor, and the output terminals of the doubly salient pole motor are connected to the input terminals of the excitation winding. The control circuit includes an isolation circuit, a fault detection circuit, three Phase current sampling circuit, excitation current sampling circuit, PWM control circuit, overcurrent and overvoltage protection circuit, ADC module, position detection circuit, speed calculation circuit, logic control circuit, capture unit, speed loop, current loop, hysteresis comparator and PI regulator, wherein the input terminal of the fault detection circuit is connected to the output terminal of the IPM, the output terminal of the fault detection circuit is connected to the input terminal of the overcurrent and overvoltage protection circuit, and the output terminal of the overcurrent and overvoltage protection circuit is connected to the input of the logic control circuit terminal; the three input terminals of the three-phase current sampling circuit are respectively connected to the three output terminals of the IPM, the output terminal of the three-phase current sampling circuit is connected to the input terminal of the ADC module, and the output terminal of the ADC module is connected to the negative input terminal of the current loop Connection; the input end of the excitation current sampling circuit is connected with the output end of the excitation winding, the output end of the excitation current sampling circuit is connected with the input end of the position detection circuit, one output end of the position detection circuit is connected with the input end of the capture unit, and the capture unit The output end of the position detection circuit is connected with the input end of the logic control circuit, the other output end of the position detection circuit is connected with the input end of the speed calculation circuit, the output end of the speed calculation circuit is connected with the negative input end of the speed loop; the output end of the speed loop is connected with the negative input end of the speed loop The input terminal of the PI regulator is connected, the output terminal of the PI regulator is connected to the positive input terminal of the current loop, the output terminal of the current loop is connected to the input terminal of the logic control circuit, and the output terminal of the logic control circuit is sequentially passed through the PWM control circuit, isolated The circuit is connected to the input of the IPM.

The control method of the position sensorless doubly salient motor system is to use the power supply to drive the doubly salient motor through the IPM, use the excitation current sampling circuit to sample the output excitation current if of the excitation winding, the excitation current sampling circuit outputs the pulse position signal, and sample the excitation current The pulse position signal output by the circuit passes through the position detection circuit and the speed calculation circuit in turn to obtain the actual speed ω _m of the doubly salient motor, and the output excitation current of the excitation winding passes through the position detection circuit and the capture unit in turn to obtain the trigger signal; a three-phase current sampling circuit is adopted Collect the three-phase input current of the doubly salient motor, pass the collected three-phase input current of the doubly salient motor through the ADC module to obtain the phase current i _P , and compare the actual speed ω _m of the doubly salient motor with the given doubly salient The real-time speed difference of the doubly salient motor is obtained through the speed loop ω _m ^* of the double-salient motor, and the given phase current i _P ^* is obtained by passing the real-time speed difference of the doubly salient motor through the PI regulator, and the given The phase current _iP ^* and the phase current _iP pass through the current loop to obtain the real-time current difference, and pass the real-time current difference through the hysteresis comparator to obtain a step signal; use the fault detection circuit to detect IPM to obtain the fault signal of the doubly salient pole motor, and the The fault signal of the doubly salient motor passes through the overcurrent and overvoltage protection circuit to obtain high and low level signals; the trigger signal, step signal, and high and low level signals are passed through the logic control circuit to obtain the excitation signal, and the excitation signal is passed through the isolation circuit to obtain the IPM The driving signal is used to control the driving voltage and driving current output by the IPM, that is, the three-phase input current of the doubly salient motor.

As shown in Figure 2, the mutual inductance of the position sensorless electrically excited double salient pole motor is the largest at the coincidence of the stator tooth pole and the rotor tooth pole, and the minimum mutual inductance is when the stator tooth pole and the rotor tooth pole are farthest apart. According to the basic theory of the electrically excited double salient pole motor, the operation of the electrically excited double salient pole motor depends on the positive current in the inductance rising area and the negative current in the inductance falling area. When the electric excitation double salient pole motor with position sensor is running, the rotor position information is obtained by relying on the position sensor, the phase current is at the moment when the inductance starts to rise from the minimum value, the moment when the inductance starts to fall from the maximum value, and the moment when the inductance drops to the minimum value to reverse. It can be seen from Figure 2 that there is a corresponding relationship between the excitation current fluctuation of the electrically excited doubly salient pole motor and the position of the stator and rotor as well as the three-phase mutual inductance, the excitation current fluctuation cycle is consistent with the current commutation cycle, and the excitation current fluctuation position is exactly the position in phase. Different rotor positions correspond to different distributions of the motor's magnetic field, and the excitation magnetic field will change with the rotor position, so the excitation current fluctuations can be used to obtain rotor position information.

As shown in Figure 3, the excitation current sampling circuit consists of a current sensor, two low-pass filters, a differentiator, an inverter, a zero-crossing comparator and a one-shot trigger. The excitation current sampled by the current sensor is filtered by the first-stage low-pass filter to eliminate high-frequency burrs; and then passed through the differentiator, inverter, second-stage low-pass filter, zero-crossing comparator and one-shot Get the pulse position signal.

As shown in Figure 4, the pulse position signal of the electric excitation double salient motor is obtained after the excitation current passes through the sampling conditioning circuit. It can be seen that the pulse position signal has a corresponding relationship with the excitation current fluctuation. Every time the excitation current fluctuates, a pulse position signal is generated. The pulse signal is in the same phase as the position where the excitation current fluctuates, and the position of the pulse signal is exactly the three-phase current commutation s position. Therefore, the pulse signal can just be used to replace the position sensor to drive the electrically excited double salient pole motor.

As shown in FIG. 5 , the pulse position signal is used to obtain the driving signal of the IPM through the control system shown in FIG. 1 to control the driving current output by the IPM, that is, the three-phase input current of the doubly salient motor. It can be seen from Fig. 5 that using the pulse position signal can realize the correct commutation of the three-phase input current of the electric excitation double salient pole motor without position sensor, that is, the positive current is passed into the phase winding in the inductance rising region, and the phase winding in the inductance falling region Apply negative current.

Claims (2)

1. double salient motor system for non-position sensor, by double salient-pole electric machine, excitation winding, main power circuit and control circuit are formed, wherein main power circuit comprises power supply and IPM, two outputs of power supply are connected with two inputs of IPM respectively, three outputs of IPM are connected with three inputs of double salient-pole electric machine respectively, the output of double salient-pole electric machine is connected with the input of excitation winding, it is characterized in that described control circuit comprises buffer circuit, failure detector circuit, the three-phase current sample circuit, the exciting current sample circuit, pwm control circuit, overcurrent-overvoltage protecting circuit, the ADC module, position detecting circuit, the revolution speed calculating circuit, logic control circuit, capturing unit, speed ring, electric current loop, hysteresis comparator and pi regulator, the fault-signal output of the input termination IPM of failure detector circuit wherein, the output of failure detector circuit is taken over the input that flows through voltage protection circuit, the input of the output termination logic control circuit of overcurrent-overvoltage protecting circuit; Three inputs of three-phase current sample circuit are connected with three outputs of IPM respectively, and the output of three-phase current sample circuit is connected with the input of ADC module, and the output of ADC module is connected with the negative input end of electric current loop; The input of exciting current sample circuit is connected with the output of excitation winding, the output of exciting current sample circuit is connected with the input of position detecting circuit, an output of position detecting circuit is connected with the input of capturing unit, the output of capturing unit is connected with the input of logic control circuit, another output of position detecting circuit is connected with the input of revolution speed calculating circuit, and the output of revolution speed calculating circuit is connected with the negative input end of der Geschwindigkeitkreis; The output of der Geschwindigkeitkreis is connected with the input of pi regulator, the output of pi regulator is connected with the positive input terminal of electric current loop, the output of electric current loop is connected with the input of logic control circuit, and the output of logic control circuit is connected with the input of IPM by pwm control circuit, buffer circuit successively.

2. control method based on the described double salient motor system for non-position sensor of claim 1, adopt power supply to drive double salient-pole electric machine by IPM, it is characterized in that adopting the sampling of exciting current sample circuit to obtain the output exciting current if of excitation winding, exciting current sample circuit output pulse position signal is exported the pulse position signal obtains double salient-pole electric machine successively through position detecting circuit, revolution speed calculating circuit actual speed ω with the exciting current sample circuit _m, the output exciting current of excitation winding is obtained triggering signal through position detecting circuit, capturing unit successively; Adopt the three-phase current sample circuit to gather the three-phase input current of double salient-pole electric machine, the three-phase input current of the double salient-pole electric machine gathered is obtained phase current i through the ADC module _P, with the actual speed ω of described double salient-pole electric machine _mWith given double salient-pole electric machine rotational speed omega _m ^*Obtain the real-time speed discrepancy of double salient-pole electric machine through speed ring, the real-time speed discrepancy of described double salient-pole electric machine is obtained given phase current i through pi regulator _P ^*, with described given phase current i _P ^*With phase current i _PIt is poor to obtain real-time current through electric current loop, and described real-time current difference is obtained step signal through hysteresis comparator; Adopt failure detector circuit to detect the fault-signal that IPM obtains double salient-pole electric machine, the fault-signal of double salient-pole electric machine is obtained the high-low level signal through overcurrent-overvoltage protecting circuit; Described triggering signal, step signal, high-low level signal are obtained pumping signal through logic control circuit, and the drive current that the drive signal that pumping signal is obtained IPM through buffer circuit is used to control IPM output is the three-phase input current of double salient-pole electric machine.

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