CN107040110A - The structure switch magnetic resistance motor of four phase 32/24 and its rotor position detecting method - Google Patents

Abstract

The invention discloses a four-phase 32/24 structure switched reluctance motor and its rotor position detection method, which comprises a rotor, a photosensitive rotor position sensor and a stator, the stator includes four phases A, B, C and D, the photosensitive The rotor position sensor consists of a turntable installed on the rotor shaft and a photoelectric pulse generator installed at 7.5° and (11.25+15×(n-1))° on both sides of the stator centerline. Through the feedback signal of the position sensor, the phase windings of the motor are guaranteed to be conducted in accordance with the predetermined target sequence, and the accurate relative position information is used for angular position control, so that the motor can run stably.

Description

Four-phase 32/24 structure switched reluctance motor and its rotor position detection method

technical field

The invention relates to the field of switched reluctance motors, in particular to a four-phase 32/24 structured switched reluctance motor and a rotor position detection method thereof.

Background technique

At present, the transmission motor system is gradually tending to develop in the direction of stepless speed change, high reliability and digitalization. The research and development of a new motor system that can realize continuously variable speed operation, high reliability, and digital speed regulation to directly drive electric vehicles has become a new development trend and an important direction of cutting-edge innovative research work in the field of electric transmission. The switched reluctance motor has a simple and compact structure and a small moment of inertia, and is suitable for working in high-temperature and high-speed environments; the windings of the motor are independent of each other, the fault tolerance is good, and the structure of the power converter is simple; the motor has many controllable parameters, The speed regulation performance is very good, the speed regulation range is wide, the starting torque is large, the transmission efficiency is high, and the power consumption is small. At present, the motor transmission system widely used at home and abroad is an induction motor, which cannot be continuously variable. If the stepless variable speed transmission is realized by a DC speed regulating motor, the structure of the DC motor is complicated, the cost is high, the maintenance is difficult and the service life is short. If the induction motor frequency conversion speed regulation system realizes the continuously variable speed transmission, the system control scheme adopts vector conversion control or direct torque control, but the calculation of vector conversion or direct torque control is complicated, and its low-speed torque is small and low-speed performance is not good. . The structure of the switched reluctance motor is simple and durable. There is no winding of any kind on the rotor, but only a simple concentrated winding on the stator. It has the characteristics of good speed regulation performance, flexible control, high working reliability, good fault tolerance and long service life, and has a good market application prospect.

Switched reluctance must work in a self-synchronous state. The position closed loop is the basic condition for the normal operation of the switched reluctance motor system, and it is also one of the important signs that distinguish the switched reluctance motor from the stepping motor. Through the feedback signal of the position sensor, the switched reluctance motor control system can ensure that the motor phase windings are conducted in accordance with the predetermined target sequence, and the phases are commutated at the correct position. At the same time, the position information is also used as the speed feedback signal of the switched reluctance motor. Speed closed-loop control of the resistance motor system. Therefore, the position feedback signal is very important in the switched reluctance motor system. The switched reluctance motor transmission system is a new type of electromechanical integrated AC speed control system, which is mainly composed of four parts: switched reluctance motor, power converter, controller and position detector. Among them, the purpose of position detection is to determine the relative position of the motor stator and rotor, as the basis for controlling the on-off of the main switching device of the power converter. At present, the switched reluctance motor transmission system generally uses a photosensitive position detector, which is composed of a photoelectric sensor fixed on the stator and an inductor (commonly known as a masking disc) that rotates coaxially with the rotor. The photoelectric sensor is usually a U-shaped structure, the transmitter is a light-emitting diode, and the receiver is a photosensitive transistor. They are respectively located on both sides of the U-shaped groove and form an optical axis. When the object passes through the U-shaped groove and blocks the optical axis, The photoelectric sensor generates a switching signal. The inductor has teeth and cogging, and the number of teeth and cogging is equal to the number of rotor poles. When the teeth or slots of the sensor pass through the U-shaped slot of the photoelectric sensor, the photosensitive element is turned on or off, and a periodic pulse signal containing rotor position information is generated. Since the existing detectors all adopt induction discs with equal tooth and slot widths, the high and low level widths of the pulse signals generated by each photoelectric sensor are equal. The combination of N position pulses separated by a certain angle, such as N=2 for four-phase motors and N=3 for three-phase motors, generates 2N position signal states with uniform widths in one power-on cycle. This position detector can determine the on-off time of each phase winding, but it cannot be used for angle control of commonly used switched reluctance motors such as four-phase 8/6-stage and three-phase 6/4-pole switched reluctance motors. At the same time, the winding commutation moment detected by this detector is not the best breaking moment. For this reason, Chinese invention patent application number CN201010622914.3 discloses an angular position detector and a detection method of a switched reluctance motor. The angular position detector has N stationary sensors and a rotating inductor; the sensor adopts a photoelectric sensor or a magnetosensitive sensor; but its structure is complex, the control strategy is cumbersome, and the torque ripple is relatively large; another example is the Chinese invention patent application number CN201510123495.1 which discloses the position detection device of the switched reluctance motor rotor and the positioning control method of the rotor, including fixing it on the rotor shaft The encoder disk, the position sensor and the supporting controller arranged on the motor housing, m teeth are evenly distributed on the encoder disk, the width of the teeth is smaller than the width of the groove between adjacent teeth, the position sensor and the rotor The axes of the rotating shafts are equally spaced and separated, K=0, 1, 2, 3, 4, 5...m-1, where n is the number of stator poles of the switched reluctance motor, and m is the number of poles of the switched reluctance motor The number of rotor poles requires high manufacturing process, high cost, and large torque ripple.

Contents of the invention

The technical problem to be solved by the present invention is that the existing switched reluctance motor rotor position detection structure is complicated, the manufacturing process cost is high, and the torque ripple is large. Therefore, a four-phase 32/24 structure switched reluctance motor and its rotor position are provided Detection method.

The technical solution of the present invention is: a four-phase 32/24 structure switched reluctance motor, which includes a rotor, a photosensitive rotor position sensor and a stator, the stator includes four phases A, B, C, and D, and the A phase includes A1, A2 , A3, A4, A5, A6, A7, A8, B phase includes B1, B2, B3, B4, B5, B6, B7, B8, C phase includes C1, C2, C3, C4, C5, C6, C7, C8 , D phase includes D1, D2, D3, D4, D5, D6, D7, D8, the concentrated windings on the eight salient poles of each phase are connected in series to form a phase winding, and the photosensitive rotor position sensor includes a The turntable and the photoelectric pulse generators installed at 7.5° and (11.25+15×(n-1))° on both sides of the stator center line, n is a positive integer, and the turntable includes uniformly staggered distribution and salient poles connected to the rotor Teeth and grooves correspond one-to-one to grooves.

The rotor position detection method of the four-phase 32/24 structure switched reluctance motor, when the teeth of the turntable turn to the position of the photoelectric pulse generator, the output state of the photosensitive rotor position sensor is 0, when the slot of the turntable turns to the position of the photoelectric pulse generator , its output state is 1, and within a rotor angle period of 15°, the photoelectric pulse generator generates two square wave signals with a phase difference of 3.75° and a duty cycle of 50%, which are combined into four different states , respectively represent the different reference positions of the four-phase windings of the motor. When the motor rotates forward and reverse, the rising edge or falling edge of the photoelectric pulse generator is reversed corresponding to the minimum inductance position of the motor inductance, which is used in the digital controller. The relative angle of the motor is calculated in the digital controller, and the logic delay is used for the angular position control of the switched reluctance motor.

The beneficial effect of the present invention is that the photosensitive rotor position sensor is used to detect the motor rotor position of the four-phase 32/24 pole structure switched reluctance motor through the half detection scheme, so that the phase windings of the motor can be conducted according to the predetermined target sequence, and the Correct position commutation ensures stable operation of the motor, high operational reliability and fault tolerance, and broad application prospects.

Description of drawings

Fig. 1 is the structural representation of four-phase 32/24 structure switched reluctance motor of the present invention;

Fig. 2 is the installation position schematic diagram of two photoelectric pulse generators of the present invention;

Fig. 3 is a schematic diagram of the positional relationship between the photoelectric pulse generator signal and the inductance change when the motor of the present invention rotates forward;

Fig. 4 is a schematic diagram of the relationship between the signal of the photoelectric pulse generator and the change position of the inductance when the motor is reversed according to the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, the present invention overcomes the prejudice of the prior art, that is, the photosensitive rotor position sensor cannot be used for the angle control of the switched reluctance motor, and a four-phase 32/24 structured switched reluctance motor is used as the photosensitive rotor position sensor. The carrier of the rotor position sensor judges the relative position of the motor inductance according to the rising edge and falling edge of the motor. It is used in the digital controller to calculate the relative angle of the motor in the digital controller and perform logic delay for the switched reluctance motor. angle position control.

Four-phase 32/24 structure switched reluctance motor, which includes a rotor, a photosensitive rotor position sensor and a stator, the stator includes four phases A, B, C, and D, and the A phase includes A1, A2, A3, A4, A5, A6, A7, A8, B phase includes B1, B2, B3, B4, B5, B6, B7, B8, C phase includes C1, C2, C3, C4, C5, C6, C7, C8, D phase includes D1, D2 , D3, D4, D5, D6, D7, D8, the concentrated windings on the eight salient poles of each phase are connected in series to form a phase winding, and the photosensitive rotor position sensor includes a turntable mounted on the rotor shaft and a The photoelectric pulse generator at 7.5° on both sides of the line, (11.25+15×(n-1))°, n is a positive integer, and the turntable includes uniformly staggered distribution and one-to-one correspondence with the salient poles and grooves of the rotor teeth and slots.

The rotor position detection device of the 32/24 pole structure four-phase switched reluctance motor is a photosensitive rotor position sensor, which operates according to the "minimum reluctance principle": the rotor position is detected by the rotor position detector, and the rotor position is detected by the DSP or single-chip microcomputer according to the position of the rotor position detector. output signal to determine the relative position of the stator and rotor; then the DSP or microcontroller outputs the control signal to control the conduction and shutdown of the upper tube and the lower tube of the four-phase asymmetrical half-bridge power converter, so that the power supply is connected to the four phases The phase winding of the switched reluctance motor with 32/24 pole structure is energized and de-energized to attract the rotor to rotate in the direction of the minimum reluctance position between the stator and the rotor. The rotor position detection scheme adopts the half detection scheme. Through the feedback signal of the position sensor, the phase windings of the motor are guaranteed to be conducted in accordance with the predetermined target order, and the phases are commutated at the correct position, so that the motor can run stably. The photosensitive rotor position sensor is composed of photoelectric pulse Composed of a generator and a turntable, the teeth and slots of the turntable are equal to the number of salient poles of the motor rotor and the number of concave grooves of the rotor, both of which are 24, and the teeth and slots of the turntable are evenly distributed, occupying an angle of 7.5°, and the turntable is fixed on the rotor On the shaft, it rotates synchronously with the motor rotor. The rotor position detection scheme adopts half of the detection scheme and uses two photoelectric pulse generators P and Q. The angle between the photoelectric pulse generators P and Q is (15×n+3.75)°, and respectively Fixed at 7.5°, (11.25+15×(n-1))° on the left and right sides of the center line of the stator pole, n is a positive integer, at this time, when the motor rotates forward and reverse, the rising edge of the photoelectric pulse generator is reversed Or the falling edge flip corresponds to the minimum inductance position of the motor inductance. When n=1, the angle between the photoelectric pulse generator P and Q is 18.75°, which are respectively located at 7.5° and 11.25° on the left and right sides of the center line of the stator pole; when When n=2, the angle between P and Q of the photoelectric pulse generator is 33.75°, which are respectively located at 7.5° and 26.25° on the left and right sides of the center line of the stator pole; and so on, the angle between the minimum inductance position and the maximum inductance position of the motor is 7.5°. At this time, the adjustable turntable makes the motor rotate forward and reverse, the corresponding relationship between the motor position signal and the inductance is shown in Figure 3 or 4, where Figure 3 is the corresponding relationship between the position signal and the inductance corresponding to the forward rotation of the motor , Figure 4 is the corresponding relationship between the position signal and the inductance corresponding to the motor reversal. The rising edge reversal or falling edge reversal of the photoelectric pulse generator corresponds to the minimum inductance position of the motor inductance, which is used in the digital controller. In the digital controller Calculate the relative angle of the motor and perform logic delay for angular position control of the switched reluctance motor. .

When the protruding teeth of the turntable turn to the slotted photoelectric pulse generator P, Q position, when the light of the light-emitting tube of the position sensor is blocked, the output state of the sensor is 0, and when it is not blocked, its output state is 1, Within a rotor angular period of 15°, P and Q generate two square wave signals with a phase difference of 3.75° and a duty cycle of 50%, which are combined into four different states, representing the different phases of the four-phase windings of the motor. Reference location.

As shown in Figure 2, if the relative position shown in the figure is set as the zero point of the timing, the output state of the position sensor is P=1, Q=1; the rotor rotates counterclockwise and turns 3.75°, and the output state of the position sensor changes to P =1, Q=0; turn 3.75° further, the output state of the position sensor becomes P=0, Q=0; turn 3.75° further, the output state of the position sensor becomes P=0, Q=1; turn again 3.75°, the rotor has rotated through a rotor angle cycle of 15°, the output state of the position sensor returns to the initial state P=1, Q=1, and so on, the rotor position state information of the switched reluctance motor can be obtained, so that the motor phase The windings are conducted in accordance with the predetermined target sequence, and the phases are commutated at the correct position to ensure the stable operation of the motor.

For a switched reluctance motor with a rated power of 30kw, a rated speed of 5600r/min, and a rated voltage of 336V, the torque ripple coefficient of a motor with a 32/24 structure and the above position detection method is 1.96, and a motor with a 16/12 structure The torque ripple coefficient of the motor is 3.07, and the torque ripple coefficient of the motor with 12/8 structure is 5.13. It can be seen that the above-mentioned four-phase 32/24 structure switched reluctance motor and its rotor position detection method can reduce the torque ripple. The rotor position detection scheme adopts a half detection scheme, and the feedback signal of the position sensor can ensure that the motor phase winding is in accordance with the predetermined target. The sequence is turned on and used for angular position control based on accurate relative position information, so that the motor can run stably.

Claims (2)

1. Four-phase 32/24 structure switched reluctance motor, characterized in that it includes a rotor, a photosensitive rotor position sensor and a stator, the stator includes four phases A, B, C, and D, and the A phase includes A1, A2, and A3 , A4, A5, A6, A7, A8, B phase includes B1, B2, B3, B4, B5, B6, B7, B8, C phase includes C1, C2, C3, C4, C5, C6, C7, C8, D The phases include D1, D2, D3, D4, D5, D6, D7, D8, and the concentrated windings on the eight salient poles of each phase are connected in series to form a phase winding. The photosensitive rotor position sensor includes a turntable installed on the rotor shaft and Photoelectric pulse generators installed at 7.5° and (11.25+15×(n-1))° on both sides of the stator center line, n is a positive integer, and the turntable includes uniformly staggered distribution and the salient poles and concave poles of the rotor Slots correspond to teeth and slots one-to-one. 2. The rotor position detection method of a four-phase 32/24 structure switched reluctance motor as claimed in claim 1, wherein the output state of the photosensitive rotor position sensor is 0 when the teeth of the turntable turn to the position of the photoelectric pulse generator , when the slot of the turntable turns to the position of the photoelectric pulse generator, its output state is 1. Within a rotor angular period of 15°, the photoelectric pulse generator generates two square wave signals with a phase difference of 3.75° and a duty cycle of is 50%, and combined into four different states, representing the different reference positions of the four-phase windings of the motor. The minimum inductance position is used in the digital controller, where the relative angle of the motor is calculated, and the logic delay is used for the angular position control of the switched reluctance motor.