CN119519474A - Detection system and detection method for rotor position and rotation speed of switched reluctance motor - Google Patents

Abstract

A detection system and a detection method for the position and the rotation speed of a rotor of a switched reluctance motor belong to the technical field of position detection and rotation speed control of the switched reluctance motor. The automatic transmission device comprises a synchronous rotating position coding fluted disc (2) and a sensor mechanism (3), and is characterized in that the position coding fluted disc (2) comprises an absolute position coding fluted disc (5) and an incremental position coding fluted disc (6) which are coaxially arranged, the absolute position coding fluted disc (5) or the incremental position coding fluted disc (6) is coaxially fixed with a motor shaft (4), and the sensor mechanism (3) comprises an absolute position sensor (24) and an incremental position sensor (27). In the system and the method for detecting the rotor position and the rotating speed of the switched reluctance motor, the increment position coding fluted disc is arranged, so that the increment position coding with high resolution is increased, the dynamic response performance of the switched reluctance motor is good when the switched reluctance motor runs at a low speed, and the rotating speed of the motor can still be kept stable when the load torque fluctuates in a large range.

Description

Detection system and detection method for rotor position and rotation speed of switched reluctance motor

Technical Field

A detection system and a detection method for the position and the rotation speed of a rotor of a switched reluctance motor belong to the technical field of position detection and rotation speed control of the switched reluctance motor.

Background

The switch reluctance motor is a stator and rotor doubly salient variable reluctance motor, the stator and the rotor are formed by laminating silicon steel sheets, concentrated windings are wound on the stator poles, and the rotor is free of windings and permanent magnets. The motor can be designed into a plurality of different phase number structures, and the pole numbers of the stator and the rotor can be matched in a plurality of different ways. The motor has the advantages of simple structure, reliable performance, strong impact resistance, small starting current, large starting torque, wide speed regulation range, high efficiency and the like.

In order to control the operation of the switched reluctance motor, the controller needs to know the position information of the rotor, which can be acquired by a position detection sensor, and the position information is converted into an electric pulse signal to be sent to the controller. Rotor position detection performance is a key to reliable operation of a switched reluctance motor and is also a hot spot of research.

The most commonly used rotor position detection mode of the switch reluctance motor at present is a mode of coding fluted disc and a position sensor, the coding fluted disc adopts a fluted structure, the position sensor adopts a fluted hall sensor or a fluted photoelectric sensor, the fluted disc rotates in the fluted of the sensor to generate a position code, the angle period of the code is the angle that the coding fluted disc rotates by one tooth and one groove, and also the angle that the motor rotor rotates by one tooth and one groove, the position code characterizes the relative position of the motor rotor and the stator, at least comprises the maximum inductance position and the minimum inductance position of the switch reluctance motor, the switch reluctance controller controls the switching and the phase change of motor current according to the position code, meanwhile, the actual rotating speed of the motor is calculated according to the position signal, and the controller controls the motor winding current according to the deviation of the set rotating speed and the actual rotating speed, so as to control the torque of the motor. The detection method has the problems that when the motor runs at a low speed, the time for changing the position code is long, the time for calculating and updating the rotating speed is also long, if the load is suddenly changed, the fluctuation of the rotating speed of the motor is large, and the dynamic response performance of the motor is poor, so that the detection method has influence on the usability of the rapier loom, the electric screw press, the pumping unit and other occasions needing low-speed running, frequent start and stop and frequent forward and reverse running.

The switch reluctance motor also adopts an integrated encoder to realize the motor rotor position detection at the non-shaft end of the motor through mechanical connection, so that the motor can generate a lot of pulses for one turn, the problem of dynamic response during low-speed operation of the motor can be solved, but the motor is used in the occasion with large impact load, frequent start and stop or frequent forward and reverse rotation, and the encoder is easy to be damaged by impact.

The switch reluctance motor can also adopt a split rotary transformer to detect the rotor position, and the mechanical connection problem of the integral encoder is overcome. Because the angular resolution is high, the rotary transformer can solve the problem of dynamic response at low speed, but is used in the occasion of frequent start-stop, frequent forward and reverse rotation and large impact load, the motor shaft has play, and the bearing abrasion fast play becomes large, so that the play fluctuation between the stator and the rotor of the rotary transformer is large, thereby influencing the acquisition precision of the rotary transformer. Because the signals generated by the rotary transformer are sine and cosine voltage signals and are generated by magnetic field induction between the stator and the rotor, the signals are easily influenced by the magnetic field of the motor or the external magnetic field, and the reliability is also influenced.

Disclosure of Invention

The invention aims to solve the technical problems of overcoming the defects of the prior art and providing a detection system and a detection method for the rotor position and the rotation speed of a switched reluctance motor, wherein the high-resolution incremental position coding is increased by arranging an incremental position coding fluted disc, the dynamic response performance of the switched reluctance motor is good when the switched reluctance motor runs at a low speed, and the rotation speed of the motor can still be kept stable when the load torque fluctuates in a large range.

The technical scheme adopted for solving the technical problems is as follows: the detection system for the rotor position and the rotating speed of the switch reluctance motor comprises a position coding fluted disc which rotates synchronously with a motor shaft and a sensor mechanism which rotates relative to the position coding fluted disc, wherein the position coding fluted disc and the sensor mechanism are coaxially arranged, and the detection system is characterized in that: the position coding fluted disc comprises an absolute position coding fluted disc and an incremental position coding fluted disc which are coaxially arranged, the absolute position coding fluted disc or the incremental position coding fluted disc is coaxially fixed with a motor shaft, and the sensor mechanism comprises an absolute position sensor which is mutually induced with the absolute position coding fluted disc and generates pulse signals and an incremental position sensor which is mutually induced with the incremental position coding fluted disc and generates the pulse signals.

Preferably, the absolute position coding fluted disc is sleeved outside the incremental position coding fluted disc at intervals, absolute fluted disc teeth are vertically arranged at the edge of the absolute position coding fluted disc, the absolute fluted disc teeth pass through the absolute position sensor, incremental fluted disc teeth are vertically arranged at the edge of the incremental position coding fluted disc, and the incremental fluted disc teeth pass through the incremental position sensor.

Preferably, a plurality of absolute fluted disc fixing holes are formed in the disc surface of the absolute position coding fluted disc, incremental fluted disc fastening holes corresponding to the absolute fluted disc fixing holes one by one are formed in the disc surface of the incremental position coding fluted disc, and a positioning mechanism is further arranged between the absolute position coding fluted disc and the incremental position coding fluted disc.

Preferably, the sensor mechanism comprises a housing fixed to a surface of a motor end cap of the switched reluctance motor, the motor shaft passing through the housing, the housing the position-encoding fluted disc therein.

Preferably, a detection circuit board is fixed on the inner wall of the cover body, a position signal processing circuit is arranged on the surface of the detection circuit board, and the absolute position sensor and the incremental position sensor are connected with the position signal processing circuit.

Preferably, the detection circuit board is fan-shaped, the absolute position sensor and the increment position sensor are respectively provided with a plurality of detection circuit boards, the circle center of the detection circuit board is taken as the vertex, the plurality of the absolute position sensors are arranged at equal angular intervals, and the plurality of the increment position sensors are arranged at equal angular intervals.

Preferably, on the surface of the detection circuit board, the circle center of the detection circuit board is taken as a vertex, the included angle between any two adjacent absolute position sensors is 15 degrees, the included angle between any two adjacent incremental position sensors is 18 degrees, and the incremental position sensors are arranged between the two adjacent absolute position sensors.

Preferably, a lead terminal is provided on a side portion of the cover body, and the guide is connected to the detection circuit board through the lead terminal.

A detection method implemented by the detection system for the rotor position and the rotation speed of the switched reluctance motor according to any one of claims 1 to 8, comprising the following steps:

step1, defining a 32-bit circular queue array, wherein the pulse number generated by rotating an incremental coding tooth circle is P, the length of the array is P+2, and defining a 16-bit head pointer variable and a 16-bit tail pointer variable;

step 2, the increment position coding fluted disc rotates, the increment position sensor signal jumps, a microprocessor connected with the increment position sensor captures the jump and then generates interruption, and an interruption program records the time and the code of the timer when the interruption occurs;

Step 3, the interrupt program judges whether the circular queue is full, if yes, the head pointer is added by one, the tail pointer is added by one, and the interrupt time at the current position is stored in the circular queue;

Step 4, the microprocessor determines the pulse number of the current calculated rotating speed according to the previous rotating speed value, and sets the previous rotating speed value as S, the proportionality coefficient as R and the pulse number of the current calculated rotating speed as C, wherein C=S/R, if C is larger than the pulse number P generated by rotating the increment position coding tooth circle once, C=P, and if C is smaller than 1, C=1;

Step 5, judging whether the length of the data stored in the circular queue is more than or equal to C+1, if not, waiting for a sufficient number of position pulse time to be stored in the circular queue, if so, taking out the data T1 pointed by the tail pointer from the circular queue, then taking out the data T2 at the C position before the tail pointer, and calculating the interval time difference of the two to be T;

And 6, setting the time of M timing units of the timer to be 1 mu s, and calculating the rotating speed n of the motor to be n=60000000 times M times C/T/P (r/min) according to the total pulse number P of one circle of the tooth disc and the interval time T of C, C pulses required for calculating the rotating speed.

Compared with the prior art, the invention has the following beneficial effects:

In the system and the method for detecting the rotor position and the rotating speed of the switched reluctance motor, the increment position coding fluted disc is arranged, so that the increment position coding with high resolution is increased, the dynamic response performance of the switched reluctance motor is good when the switched reluctance motor runs at a low speed, and the rotating speed of the motor can still be kept stable when the load torque fluctuates in a large range.

In the detection system and the detection method for the rotor position and the rotating speed of the switch reluctance motor, the coding fluted disc and the position sensor are arranged in a split mode, and the rotor position signal is detected in a non-contact mode, so that the requirements of motor application occasions of frequent impact, frequent start and stop and frequent forward and reverse rotation can be met.

In the system and the method for detecting the rotor position and the rotating speed of the switched reluctance motor, an algorithm for dynamically changing the pulse number required by calculating the rotating speed according to the actual rotating speed is adopted, and the same dynamic response performance can be realized by adopting one set of PID parameters within the full rotating speed range of the motor, so that the problem of unstable operation caused by different changes of the PID parameters according to different rotating speeds is solved.

In the detection system and the detection method for the position and the rotating speed of the rotor of the switch reluctance motor, the position circuit board is arranged in the sensor cover, and a cable fastening head wire outlet mode is adopted, so that the tightness is good, and the installation, the adjustment and the maintenance are more convenient.

The system and the method for detecting the rotor position and the rotating speed of the switch reluctance motor have the advantages of good dynamic response performance and impact resistance at low speed, being applicable to switch reluctance motor driving occasions requiring low-speed operation, impact load, frequent start and stop or frequent forward and reverse rotation and the like, and having simple structure, reliable operation, low cost and the like.

Drawings

FIG. 1 is an exploded view of a system for detecting rotor position and rotational speed of a switched reluctance motor.

FIG. 2 is a schematic diagram of a position encoding fluted disc of a detecting system for detecting the position and the rotation speed of a rotor of a switch reluctance motor.

FIG. 3 is a schematic diagram of the structure of the incremental position encoding fluted disc of the detecting system for the rotor position and the rotating speed of the switch reluctance motor.

FIG. 4 is a schematic diagram of the structure of the absolute position encoding fluted disc of the detecting system for the rotor position and the rotating speed of the switch reluctance motor.

FIG. 5 is a schematic diagram of a sensor mechanism of a system for detecting rotor position and rotational speed of a switched reluctance motor.

FIG. 6 is a schematic diagram of a detecting system for rotor position and speed of a switched reluctance motor.

Fig. 7 is a schematic diagram of a circuit board structure of a detection system for detecting the rotor position and the rotation speed of the switched reluctance motor.

Fig. 8 is a schematic diagram of a motor end cover structure of a detecting system for rotor position and rotation speed of a switched reluctance motor.

Fig. 9 is a schematic diagram of a position detection circuit of a detection system for rotor position and rotational speed of a switched reluctance motor.

FIG. 10 is a schematic diagram of the input of pulse signals to the microprocessor and the isolation circuit of the detection system for rotor position and speed of the switched reluctance motor.

FIG. 11 is a flow chart of a method for detecting rotor position and rotational speed of a switched reluctance motor.

The motor end cover 2, the position coding fluted disc 3, the sensor mechanism 4, the motor shaft 5, the absolute position coding fluted disc 6, the increment position coding fluted disc 7, the increment gear ring 8, the increment fluted disc surface 9, the increment fluted disc fastening hole 10, the increment fluted disc positioning hole 11, the increment fluted disc spigot 12, the absolute fluted disc tooth 13, the absolute fluted disc surface 14, the absolute fluted disc fixing hole 15, the absolute fluted disc positioning column 16, the absolute fluted disc spigot 17, the detection circuit board 18, the lead terminal 19, the cover body shaft hole 20, the cover body 21, the circuit board fixing hole 22, the cover body mounting hole 23, the cover body fixing hole 24, the absolute position sensor 25, the plate body 26, the plate body fixing hole 27, the increment position sensor 28, the end cover mounting spigot 29 and the end cover fixing hole.

Detailed Description

Fig. 1 to 11 are diagrams illustrating preferred embodiments of the present invention, and the present invention is further described below with reference to fig. 1 to 11.

As shown in fig. 1, a system for detecting the rotor position and the rotation speed of a switched reluctance motor (hereinafter referred to as a detection system) includes a position coding fluted disc 2 coaxially fixed with a motor shaft 4 of the switched reluctance motor, and a sensor mechanism 3, wherein the sensor mechanism 3 is coaxially fixed with a motor end cover 1 of the switched reluctance motor, and the position coding fluted disc 2 is covered therein. In the detection system, a motor end cover 1 is an end cover of a non-shaft extending end in a switch reluctance motor, a motor shaft 4 passes through the center of the motor end cover 1, and the switch reluctance motor drives the motor shaft 4 to coaxially rotate at the motor end cover 1 during rotation, and as a position coding fluted disc 2 is coaxially fixed with the motor shaft 4, a sensor mechanism 3 is coaxially fixed with the motor end cover 1, and therefore, when the motor shaft 4 rotates, the position coding fluted disc 2 and the sensor mechanism 3 relatively rotate.

As shown in fig. 2, the position-coding fluted disc 2 includes an absolute position-coding fluted disc 5 and an incremental position-coding fluted disc 6 which are coaxially fixed, wherein the incremental position-coding fluted disc 6 is integrally located at the inner side of the absolute position-coding fluted disc 5, and the absolute position-coding fluted disc 5 is coaxially fixed with the motor shaft 4 in a shrink fit manner, so that the switch reluctance motor will not loosen even if frequently starts and stops to be impacted. The outer ring of the absolute position coding fluted disc 5 and the outer ring of the increment position coding fluted disc 6 are arranged at intervals, and the difference between the outer diameter of the absolute position coding fluted disc 5 and the outer diameter of the increment position coding fluted disc 6 is preferably 10mm.

Referring to fig. 3, the incremental position encoding fluted disc 6 comprises a circular incremental fluted disc surface 8, a circular incremental gear ring 7 is arranged at the edge of the incremental fluted disc surface 8, the incremental gear ring 7 is perpendicular to the incremental fluted disc surface 8, and a plurality of incremental position disc teeth are arranged in the incremental gear ring 7 at intervals. The center hole of the increment fluted disc surface 8 is provided with an increment fluted disc spigot 11 of the increment position coding fluted disc 6, three increment fluted disc fastening holes 9 are uniformly arranged on the outer side of the increment fluted disc spigot 11, the increment fluted disc fastening holes 9 are arc-shaped holes penetrating through the increment fluted disc surface 8, and the three increment fluted disc fastening holes 9 are positioned on the same circumference. An incremental fluted disc positioning hole 10 is formed on the side part of any one of the incremental fluted disc fastening holes 9.

Referring to fig. 4, the absolute position encoding fluted disc 5 includes a circular absolute fluted disc surface 13, a plurality of absolute fluted disc teeth 12 are uniformly arranged at the edge of the incremental fluted disc surface 8, an absolute fluted disc spigot 16 is arranged at the central hole of the incremental fluted disc surface 8, the central hole of the absolute fluted disc spigot 16 is equal to the central hole of the incremental fluted disc surface 8 in diameter, and the thickness of the absolute fluted disc spigot 16 is about 10mm greater than the thickness of the incremental fluted disc surface 8, so that the absolute position encoding fluted disc 5 and the motor shaft 4 are ensured to be fixed, and a large enough holding force is provided. The diameter of the absolute fluted disc surface 13 of the absolute position coding fluted disc 5 is determined by the number of the motor seat, if the number of the motor seat is large, the diameter of the motor shaft 4 is large, the diameter of the fluted disc is large, and for a motor with the number of the motor seat of 180-315, the diameter of the disc is generally selected to be 150 mm. For a common 12/8-pole switched reluctance motor with a stator and a rotor, the rotor is of an 8-tooth 8-slot structure, and in the detection system, the absolute position coding fluted disc 5 is also designed to be of an 8-tooth 8-slot structure.

Three absolute tooth disc fixing holes 14 are uniformly arranged on the outer side of the absolute tooth disc spigot 16, and the three absolute tooth disc fixing holes 14 are in one-to-one correspondence with the three incremental tooth disc fastening holes 9 on the incremental position coding tooth disc 6. And an absolute fluted disc positioning column 15 is arranged at the side part of any one absolute fluted disc fixing hole 14. The absolute fluted disc positioning column 15 on the surface of the absolute fluted disc surface 13 corresponds to the incremental fluted disc positioning hole 10 on the surface of the incremental fluted disc surface 8.

When the absolute position coding fluted disc 5 and the incremental position coding fluted disc 6 are combined, the absolute fluted disc positioning column 15 passes through the incremental fluted disc positioning holes 10, at the moment, three absolute fluted disc fixing holes 14 are correspondingly arranged on the lower sides of the three incremental fluted disc fastening holes 9, and the incremental fluted disc fastening holes 9 are arc-shaped holes so as to be aligned with the absolute fluted disc fixing holes 14, so that the assembly is easy. The absolute position coding fluted disc 5 and the increment position coding fluted disc 6 are radially arranged at intervals through the absolute fluted disc spigot 16, and finally the absolute position coding fluted disc 5 and the increment position coding fluted disc 6 are coaxially fixed through bolts penetrating through the increment fluted disc fastening holes 9 and screwed into the absolute fluted disc fixing holes 14.

After the absolute position coding fluted disc 5 and the increment position coding fluted disc 6 are coaxially fixed, increment position disc teeth on the outer ring of the increment position coding fluted disc 6 are positioned on the outer side of absolute fluted disc teeth 12 on the outer ring of the absolute position coding fluted disc 5, the number of the increment position disc teeth is 10-20 times that of the absolute fluted disc teeth 12, and the edge parts of the increment position disc teeth cannot be washed away due to the small tooth width of the increment position disc teeth so as to ensure that the edges of the fluted disc teeth are connected into a whole and cannot deform due to collision.

As shown in fig. 5, the sensor mechanism 3 includes a housing 20, a detection circuit board 17 is fixed on a cavity wall of an inner cavity of the housing 20, a lead terminal 18 is provided on one side of the cavity wall of the inner cavity of the housing 20, and a wire is connected to a detection circuit on the detection circuit board 17 through the lead terminal 18 and led out through a signal output by the detection circuit. A cover shaft hole 19 is formed in the middle of the cover 20, the motor shaft 4 passes through the cover shaft hole 19, and a labyrinth seal is arranged at the cover shaft hole 19 for preventing dust from entering the cover 20.

As shown in fig. 6, a circuit board fixing hole 21 is formed in the surface of the inner cavity of the cover body 20, the detection circuit board 17 is fixed in the cover body 20 through the circuit board fixing hole 21, an annular edge is arranged on the outer ring of the cover body 20, a plurality of cover body mounting holes 22 are uniformly formed in the edge, and the cover body mounting holes 22 are arc-shaped through holes. Cover fixing holes 23 are also formed between any two cover mounting holes 22, and three cover fixing holes 23 are formed. A knocking groove is respectively arranged at the outer side of each cover body fixing hole 23, and the knocking groove is formed along the radial direction of the edge.

As shown in fig. 7, the detection circuit board 17 includes a fan-shaped board body 25, and three absolute position sensors 24 are uniformly disposed on the surface of the board body 25, and an included angle between any two adjacent absolute position sensors 24 of the three absolute position sensors 24 is 15 ° with a center of a circle on the surface of the detection circuit board 17 as a vertex. The absolute position sensor 24 employs a slot type photoelectric sensor or a slot type hall sensor, which are known in the art, and the absolute toothed disc teeth 12 of the outer ring of the absolute position encoding toothed disc 5 in the position encoding toothed disc 2 pass through the three absolute position sensors 24 after the sensor mechanism 3 is fixed on the surface of the motor end cover 1.

The absolute fluted disc teeth 12 rotate in the grooves of the three absolute position sensors 24 to generate three position signals with 120 DEG phase difference, 6 pulse codes can be synthesized, the positive rotation code of a motor is '101- >100- >110- >010- >011- > 001', and the negative rotation code of the motor is '001- >011- >010- >110- >100- > 101'. The code is Gray code, only one bit jump is needed at any time, so that the microprocessor can conveniently filter interference pulse. The rotation of the rotor of the absolute position encoding fluted disc 5 for one revolution generates 48 pulses. The absolute position code characterizes the relative position of the rotor and the stator of the switched reluctance motor, is used for controlling the winding current switch and commutation, controlling the opening angle and Guan Duanjiao, and can be used for calculating the rotating speed of the motor when the rotating speed is higher.

Two incremental position sensors 27 are also provided between any adjacent two of the absolute position sensors 24, the diameter of the circumference in which the two incremental position sensors 27 are located being smaller than the diameter of the circumference in which the three absolute position sensors 24 are located. The angle between the two incremental position sensors 27 is 18 ° with the center of the plate 25 as the apex. After the sensor means 3 is fixed to the surface of the motor end cap 1, the incremental toothed disk teeth of the outer ring of the incremental position-encoding toothed disk 6 of the position-encoding toothed disk 2 pass through the two incremental position sensors 27.

In the present inspection system, the incremental position encoder disk 6 employs 80-tooth 80-slot, the incremental position sensor 27 employs a slot-type photoelectric sensor or slot hall sensor as is known in the art, and the incremental disk teeth pass through the incremental position sensor 27. The increment fluted disc teeth rotate in the two increment position sensors 27, so that pulse codes of 2 sequences of forward rotation and reverse rotation can be synthesized, wherein the forward rotation code is '00- >10- >11- > 01', and the reverse rotation code is '01- >11- >10- > 00'. The incremental position code is also Gray code, and only one bit jumps at any time, so that the microprocessor can conveniently filter interference pulses. The incremental position code can be used for calculating the rotating speed of the motor when the motor runs at medium and low speeds, can also participate in controlling the opening angle and the closing angle, and can improve the precision of the opening angle and the closing angle in the occasion of frequent start and stop and forward and reverse rotation. The increment position coding fluted disc 6 generates 320 position pulses altogether every time it rotates, when the motor speed is running to low speed 10r/min, the interval time between two pulses is 18.75ms, the microprocessor can calculate and refresh the speed every 18.75ms, and the suitable PID parameter is cooperated, the dynamic response performance requirement of load mutation can be satisfied. If only absolute code acquisition is adopted, the microprocessor can refresh the rotating speed every 125ms when the motor runs at 10r/min, and the dynamic response performance is poor.

Plate body fixing holes 26 are respectively formed in two sides of the surface of the detection circuit board 17, the arrangement mode of the plate body fixing holes 26 on two sides corresponds to that of the circuit board fixing holes 21, and fixing bolts penetrate through each plate body fixing hole 26 and then are screwed into the corresponding circuit board fixing holes 21 to fix the plate body 25 in the cover body 20.

As shown in fig. 8, an end cover mounting spigot 28 is arranged at the center of the motor end cover 1, three end cover fixing holes 29 are uniformly arranged on the outer ring of the end cover mounting spigot 28, the three end cover fixing holes 29 are in one-to-one correspondence with the three cover fixing holes 23 at the edge of the cover 20, and fixing bolts are screwed into the corresponding end cover fixing holes 29 after passing through each cover fixing hole 23, so that the cover 20 is fixed on the surface of the motor end cover 1, and the sensor mechanism 3 and the motor end cover 1 are fixed.

Because the absolute position coding fluted disc 5 does not do the angular positioning in the circumferential direction when hot-set is on the axle, therefore need to obtain the corresponding relation of position coding and motor rotor and stator position through rotating the cover body 20, therefore cover body mounting hole 22 of cover body 20 edge adopts the arc hole, and the angle of cover body mounting hole 22 is the angle of a tooth groove of absolute position coding fluted disc 5, guarantees to rotate required positioning code. The positioning mode of the position code specifically comprises the steps that a controller is adopted to electrify an A-phase winding of the motor, a stator salient pole of the A-phase winding is aligned with a rotor salient pole, the cover body 20 is rotated to a certain position, when the position code jumps between two codes, such as jump between 001 and 101, the position is the maximum inductance position of the A-phase, positioning is completed, and then a bolt for fixing the cover body 20 is screwed. The cover 20 is knocked to rotate during positioning by a knocking groove arranged at the edge of the cover 20.

As is clear from the above, the absolute position sensor 24 and the incremental position sensor 27 are provided in total with five, and the position signal processing circuits having the same five circuit configurations are provided correspondingly. The detection circuit board 17 is powered by a 12V power supply, and the power supply is provided by a power isolation module S1 of the controller main control board. Because the winding voltage and current of the switch reluctance motor are controlled to be switched on and off by the IGBT of the controller, the time of the large current of the IGBT switch is about 1 mu s, so that ringing wave interference exists, and an isolation circuit is required to be arranged in the position signal processing circuit so as to realize the anti-interference effect. The position signal processing circuit and the isolation circuit are all arranged on the surface of the plate body 25.

As shown in fig. 9, the position signal processing circuit includes a position sensor H1 (an absolute position sensor 24 or an incremental position sensor 27), the ground of the position sensor H1 is grounded, the signal output end thereof is simultaneously connected to one end of a resistor R1 and one end of a capacitor C2, the other end of the resistor R1 is connected to the positive electrode of a 12V dc power supply, and the other end of the capacitor C2 is grounded. The output end of the position sensor H1 is simultaneously connected with the input end of the Darlington tube T1, the grounding end of the Darlington tube T1 is grounded, the output end of the Darlington tube T1 is connected with the anode of the diode D1 and the cathode of the diode D2, the cathode of the diode D1 is connected with the anode of the 12V direct current power supply, and the anode of the diode D2 is grounded. The output end of the Darlington tube T1 is also connected with one end of a resistor R2, the other end of the resistor R2 is connected with one end of a capacitor C3 and a controller main board U2, and the other end of the capacitor C3 is grounded.

The position sensor H1 senses pulse signals generated by the absolute fluted disc teeth 12 or the incremental fluted disc teeth, the pulse signals are filtered through a low-pass filter circuit formed by a resistor R1 and a capacitor C2, current driving capacity is improved through a Darlington tube T1, possible high-voltage interference is filtered through level clamping diodes D1-D2, and the pulse signals are sent to a controller main control board after passing through an output current limiting resistor R2 and a filter capacitor C3. The Darlington tube can select ULN2004, has 7 paths of driving, and meets the requirement of 5 paths of sensor signals.

The detection circuit board 17 sends the position coding signal to the controller main board U2 through a cable, the signal is required to be sent to the microprocessor U3 after being isolated, and the influence of motor side interference on a control circuit is reduced. The isolation circuit includes a high-speed optocoupler U1, as shown in fig. 10, a signal output by the darlington tube T1 is connected to one end of a resistor R3 through a corresponding port of the controller main board U2, and the other end of the resistor R3 is simultaneously connected to one end of a capacitor C6, one end of a resistor R4, an anode of a diode D3, and an input cathode of the optocoupler U1. The positive pole of the 12V direct current power supply is connected with the other end of the capacitor C6, the other end of the resistor R4, the cathode of the diode D3 and the input positive pole of the optocoupler U1.

The positive pole of 3.3V DC power supply connects one end of electric capacity C7, the power input of opto-coupler U1. The output end of the optical coupler U1 is connected with a resistor R5 in series and is connected with a capacitor C8 and the input end of an inverter U4, the other end of the capacitor C8 is grounded, and the output end of the inverter U4 is connected with a microprocessor U3.

The position pulse signal is sent to the input port of the high-speed optocoupler through a current-limiting resistor R3, a filter capacitor C6, a protection resistor R4 and a reverse voltage clamping diode D3, and the output signal of the optocoupler is subjected to low-pass filtering composed of R5 and C8, is subjected to signal shaping through an inverter U4 and is then sent to high-speed capturing input ports CIN 0-CIN 4 of the microprocessor U3. The high-speed optocoupler can select TLP2168, the microprocessor U3 can select ARM kernel chips such as LPC43xx series, and the high-speed optocoupler is provided with a plurality of high-speed capturing input ports and PWM output, and is suitable for motor control.

When the position signal pulse jumps, the high-speed capturing input port of the microprocessor U3 triggers an interrupt, and the interrupt program can record the absolute position code and the increment position code at the moment and the jump time. The interruption program of absolute position coding controls the on-off of winding current, and can also be used for calculating the rotating speed, and the interruption control program of incremental position coding is mainly used for pulse time storage and rotating speed calculation, and can also be used for high-precision on-angle and off-angle control.

The microprocessor U3 stores the incremental position pulse time in a circular queue mode, after the queue is full, the newly acquired pulse time automatically covers the earliest pulse time, the circular queue sequentially stores the latest position pulse sequence time, and the rotating speed calculation program takes out data from the circular queue to calculate the rotating speed of the motor. The microprocessor U3 determines the position pulse number of the motor rotating speed calculated at this time according to the previous rotating speed value of the motor, the pulse number is in direct proportion to the rotating speed, the maximum value is the pulse number generated by one rotation of the rotor plus 1, and the minimum value is 2 pulses.

As shown in fig. 11, the detection method implemented by the detection system includes the following steps:

step 1, initializing a program, and establishing a circular queue:

Defining a 32-bit circular array, and the pulse number generated by rotating the incremental coding tooth disk one circle is P, the array length is P+2, and defining a 16-bit head pointer variable and a 16-bit tail pointer variable.

Step 2, recording position pulse jump time by an interrupt program:

The increment position coding fluted disc 6 rotates, the increment position sensor 27 generates a signal jump, the microprocessor U3 high-speed capturing input pin CTIN _3 or CTIN _4 generates a jump, an interrupt is generated, and an interrupt program records the time and the code of the timer when the interrupt occurs.

Step 3, storing the position pulse interrupt time into a circulation queue:

the interrupt routine determines whether the circular queue is full, and if so, increments the head pointer by one. The tail pointer is added by one, and the interrupt time of the current position is stored in the circular queue.

Step 4, determining the number of position pulses required for calculating the rotating speed:

the rotation speed calculation program determines the pulse number of the current calculation rotation speed according to the previous rotation speed value. Let the previous rotation speed value be S, the proportionality coefficient be R, the current pulse number of the calculated rotation speed be C, c=s/R, c=p if C is greater than the pulse number P generated by one rotation of the incremental position encoding fluted disc 6, c=1 if C is less than 1.

Step 5, the corresponding position pulse time is taken out from the circular queue, and the time difference is calculated:

Judging whether the length of the data stored in the circular queue is greater than or equal to C+1, if not, waiting for a sufficient number of position pulse time to be stored in the circular queue, if so, taking out the data T1 pointed by the tail pointer from the circular queue, then taking out the data T2 at the C position before the tail pointer, and calculating the interval time difference of the two to be T.

Step6, calculating the rotating speed of the motor:

setting the time of M timing units of the timer to be 1 mu s, and calculating the rotating speed n of the motor to be n=60000000 xMxC/T/P (r/min) according to the total pulse number P of one circle of the tooth disc and the interval time T of C, C pulses of the pulse number required for calculating the rotating speed.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the invention in any way, and any person skilled in the art may make modifications or alterations to the disclosed technical content to the equivalent embodiments. However, any simple modification, equivalent variation and variation of the above embodiments according to the technical substance of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. A detection system for the rotor position and the rotating speed of a switch reluctance motor comprises a position coding fluted disc (2) which rotates synchronously with a motor shaft (4), and a sensor mechanism (3) which rotates relative to the position coding fluted disc (2), wherein the position coding fluted disc (2) and the sensor mechanism (3) are coaxially arranged, and the switch reluctance motor rotor position and rotating speed detection system is characterized in that the position coding fluted disc (2) comprises an absolute position coding fluted disc (5) and an increment position coding fluted disc (6) which are coaxially arranged, the absolute position coding fluted disc (5) or the increment position coding fluted disc (6) is coaxially fixed with the motor shaft (4), and the sensor mechanism (3) comprises an absolute position sensor (24) which is mutually inducted with the absolute position coding fluted disc (5) and generates pulse signals, and an increment position sensor (27) which is mutually inducted with the increment position coding fluted disc (6) and generates pulse signals.

2. The system for detecting the rotor position and the rotating speed of the switched reluctance motor according to claim 1, wherein the absolute position coding fluted disc (5) is sleeved outside the incremental position coding fluted disc (6) at intervals, absolute fluted disc teeth (12) are vertically arranged at the edge of the absolute position coding fluted disc (5), the absolute fluted disc teeth (12) pass through an absolute position sensor (24), incremental fluted disc teeth are vertically arranged at the edge of the incremental position coding fluted disc (6), and the incremental fluted disc teeth pass through an incremental position sensor (27).

3. The system for detecting the rotor position and the rotating speed of the switched reluctance motor according to claim 2, wherein a plurality of absolute fluted disc fixing holes (14) are formed in the disc surface of the absolute position coding fluted disc (5), incremental fluted disc fastening holes (9) which are in one-to-one correspondence with the absolute fluted disc fixing holes (14) are formed in the disc surface of the incremental position coding fluted disc (6), and a positioning mechanism is further arranged between the absolute position coding fluted disc (5) and the incremental position coding fluted disc (6).

4. The system for detecting the rotor position and the rotating speed of the switched reluctance motor according to claim 1, wherein the sensor mechanism (3) comprises a cover body (20), the cover body (20) is fixed on the surface of a motor end cover (1) of the switched reluctance motor, the motor shaft (4) passes through the cover body (20), and the position coding fluted disc (2) is covered in the cover body (20).

5. The system for detecting the rotor position and the rotating speed of the switched reluctance motor according to claim 4, wherein a detection circuit board (17) is fixed on the inner wall of the cover body (20), a position signal processing circuit is arranged on the surface of the detection circuit board (17), and an absolute position sensor (24) and an incremental position sensor (27) are connected to the position signal processing circuit.

6. The system for detecting the rotor position and the rotating speed of the switched reluctance motor according to claim 5, wherein the detecting circuit board (17) is fan-shaped, the absolute position sensor (24) and the incremental position sensor (27) are respectively arranged in a plurality, the circle center of the detecting circuit board (17) is taken as an apex, the absolute position sensors (24) are arranged at equal angular intervals, and the incremental position sensors (27) are arranged at equal angular intervals.

7. The system for detecting the rotor position and the rotating speed of the switched reluctance motor according to claim 5 or 6, wherein the angle between any two adjacent absolute position sensors (24) is 15 degrees, the angle between any two adjacent incremental position sensors (27) is 18 degrees, and the incremental position sensors (27) are arranged between the two adjacent absolute position sensors (24) on the surface of the detection circuit board (17) by taking the center of a circle of the detection circuit board (17) as an apex.

8. The system for detecting the rotor position and the rotation speed of the switched reluctance motor according to claim 4, wherein the lead terminal (18) is arranged at the side part of the cover body (20), and the lead terminal (18) is connected with the detection circuit board (17).

9. A detection method implemented by the detection system for the rotor position and the rotation speed of the switched reluctance motor according to any one of claims 1 to 8, comprising the following steps:

step1, defining a 32-bit circular queue array, wherein the pulse number generated by rotating an incremental coding tooth circle is P, the length of the array is P+2, and defining a 16-bit head pointer variable and a 16-bit tail pointer variable;

Step 2, the increment position coding fluted disc (6) rotates, the increment position sensor (27) generates jump in signal, the microprocessor connected with the increment position sensor (27) captures the jump and then generates interruption, and the interruption program records the time and the code of the timer when the interruption occurs;

Step 3, the interrupt program judges whether the circular queue is full, if yes, the head pointer is added by one, the tail pointer is added by one, and the interrupt time at the current position is stored in the circular queue;

step 4, the microprocessor determines the pulse number of the current calculated rotating speed according to the previous rotating speed value, and sets the previous rotating speed value as S, the proportionality coefficient as R and the pulse number of the current calculated rotating speed as C, wherein C=S/R, if C is larger than the pulse number P generated by one rotation of the increment position coding fluted disc (6), C=P, and if C is smaller than 1, C=1;

Step 5, judging whether the length of the data stored in the circular queue is more than or equal to C+1, if not, waiting for a sufficient number of position pulse time to be stored in the circular queue, if so, taking out the data T1 pointed by the tail pointer from the circular queue, then taking out the data T2 at the C position before the tail pointer, and calculating the interval time difference of the two to be T;

And 6, setting the time of M timing units of the timer to be 1 mu s, and calculating the rotating speed n of the motor to be n=60000000 times M times C/T/P (r/min) according to the total pulse number P of one circle of the tooth disc and the interval time T of C, C pulses required for calculating the rotating speed.