CN114362623B - Permanent magnet synchronous motor high-reliability starting method based on position control - Google Patents
Permanent magnet synchronous motor high-reliability starting method based on position control Download PDFInfo
- Publication number
- CN114362623B CN114362623B CN202210174702.6A CN202210174702A CN114362623B CN 114362623 B CN114362623 B CN 114362623B CN 202210174702 A CN202210174702 A CN 202210174702A CN 114362623 B CN114362623 B CN 114362623B
- Authority
- CN
- China
- Prior art keywords
- commutation
- zero
- phase
- time
- starting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
The invention discloses a permanent magnet synchronous motor high-reliability starting method based on position control, which is used for solving the starting reliability from zero speed to low speed of a motor and the step loss problem in the starting process. The start-up procedure is divided into two phases: an outer synchronization stage and a transition synchronization stage, performing a total of 32 commutation; and (3) an external synchronization stage, namely accelerating the phase change in a fixed time length, and accelerating the rotor in advance, wherein the total phase change is 14 times. The 14 th phase change is a phase change process with fixed duration. A transition synchronization stage for phase-changing according to the zero-crossing signal, wherein the total phase-changing is 18 times; and judging the authenticity of the zero crossing signal of each phase according to the relation between the phase voltage and the bus voltage of 1/2. Wherein the zero type of the 15 th phase-change zero-crossing signal is the rising edge. The invention is based on the six-step commutation control strategy of the back electromotive force zero crossing, and has low performance requirement on MCU. The open loop is started to successfully cut into the closed loop, the commutation frequency is controllable, no step is lost, the position deduction calculation is accurate, the starting reliability is good, and the false triggering and locked-rotor fault probability is low.
Description
Technical Field
The invention relates to a synchronous starting method of a permanent magnet motor, in particular to a high-reliability starting method of the permanent magnet synchronous motor based on position control.
Background
At present, the sensorless control technology is applied to a vector control and direct torque control system of a permanent magnet synchronous motor, and can well run in middle and high speed sections. However, the performance is greatly degraded in the low speed section, particularly at the time of starting, and the control accuracy is not high.
According to domestic and foreign documents and the prior art, the sensorless control technology of the permanent magnet synchronous motor can be roughly divided into two main types: one class is suitable for medium and high speeds and the other class is suitable for zero and low speeds.
The medium-speed and high-speed control method is mainly based on a motor fundamental wave model, and rotor position information is directly or indirectly obtained from counter electromotive force, so that the method is relatively easy to realize. However, the back emf signal is small at zero and low speeds and is not easily detected, especially when the motor is stationary, the back emf is zero and it is difficult to obtain the rotor position from the back emf. Therefore, zero-speed and low-speed sensorless control techniques are key and difficult to study.
Defects and deficiencies of the prior art:
the open loop starting method is more traditional, and the starting mode is simple to realize and is generally three-section starting based on six-step commutation. The motor rotor can rotate during pre-positioning, the phenomenon of step-out is easily caused during external synchronous acceleration, the number of phase-change times in the process of switching into a closed loop is uncertain after the external synchronous acceleration is finished, step-out is easily caused, and when the closed loop cannot be correctly switched into, bus current fluctuation is large, and the locked rotor fault is easily triggered by mistake.
In the position control mode, the position increment is obtained by accumulating and deducing the number of phase-change steps of the motor, and in order to ensure the accuracy of position control, the noninductive starting needs to accurately control the consistency of the number of phase-change steps of the stator in the open loop starting process and the actual rotation angle of the rotor.
The starting failure or the open loop starting process has step loss, the position increment can generate deviation through the phase change frequency calculation, the position control generally has frequent starting and stopping, the position error is overlarge due to the accumulation of the starting errors for many times, and the position control is invalid.
The position control requires that the start-up procedure cannot be performed without step loss and the number of start-up procedure steps is determined, and the start-up failure rate is extremely low.
Disclosure of Invention
In order to solve the problems, the invention provides a starting mode of a permanent magnet synchronous motor, realizes high-precision position control, and solves the problems of starting reliability from zero speed to low speed and step loss in the starting process of the motor.
The technical scheme adopted for solving the technical problems is as follows:
the method is characterized in that a six-step commutation strategy based on zero crossing of counter electromotive force is adopted for motor control, an open loop starting mode is adopted for software driving starting, and a zero crossing signal of the counter electromotive force is obtained by comparing voltage of a UVW three-phase terminal sampled by software through AD with bus_voltage/2.
The start-up procedure is divided into two phases: an outer sync phase and a transition sync phase, which perform a total of 32 commutation.
And (3) an external synchronization stage, namely accelerating the phase change in a fixed time length, and accelerating the rotor in advance, wherein the total phase change is 14 times.
The 14 th commutation timeout time is 1/4 of the 13 th commutation, the phase is a commutation process with fixed duration, the commutation is accelerated, the included angle between the magnetomotive force of the stator and the magnetomotive force of the rotor is reduced from 180 degrees, and finally, the included angle between the magnetomotive force vectors of the stator and the rotor is ensured to be kept within the range of 60-120 degrees.
And a transition synchronization stage, wherein the stage has obvious back electromotive force, reads zero crossing points, and commutates according to zero crossing signals, and the stage is totally 18 times of commutates.
In this stage, the authenticity of zero crossing signals of each phase is judged according to the relation between the phase voltage and the bus voltage of 1/2 so as to shield zero misjudgment caused by uncertainty of demagnetization time.
The zero type of the 15 th phase-change zero-crossing signal is a rising edge, and the zero-crossing scanning timeout time is longer than 15ms, so that enough zero-crossing detection time is ensured to adapt to load change and change of the synchronous effect;
when the 15 th commutation scan reaches a qualified zero crossing signal: the advance angle time is set to be 1/2 of the zero crossing time of the current commutation period; setting the demagnetizing time to be 1/8 of the 14 th commutation period time; the zero crossing scan timeout is set to 15ms.
When the 15 th commutation does not scan for a qualified zero crossing signal and the zero crossing scan times out: updating commutation period time according to the amplitude of the back electromotive force captured by the last commutation ending point, starting the commutation failure count to be increased by 1, and executing the following three choices by software:
the time of the advance angle is changed according to the last commutation period time, so as to estimate the optimal commutation point;
changing the demagnetizing time according to the last commutation period time;
the pwm duty cycle limit is changed according to the last commutation period time to adapt to load change, so that load adaptability is improved.
The 15 th commutation process is repeated from 16 th to 32 th commutation to ensure the reliability of successful starting. When the 32 times of commutation are finished, when the commutation starting failure count is more than or equal to 4 times, the commutation starting failure is judged, and a locked-up fault is reported; and when the commutation starting failure count is smaller than 4 times, starting is successful, and commutation is continuously executed.
Further, the pwm period is 50us, and zero point detection and judgment are performed in the pwm period interrupt.
The invention has the beneficial effects that
The invention adopts a six-step phase-change control strategy based on the zero crossing of the back electromotive force, does not need a complex algorithm, has low performance requirement on MCU, and can use low-cost MCU.
The open loop is started to successfully cut into the closed loop, the commutation frequency is controllable, no step is lost, the position deduction calculation is accurate, the starting reliability is good, and the false triggering and locked-rotor fault probability is low.
Drawings
Fig. 1 is a flowchart of the starting of the permanent magnet synchronous motor provided by the invention.
Fig. 2 is a 6-step commutation timing diagram of a permanent magnet synchronous motor.
In fig. 2: t0_cnt represents the count value of the timer0 timer, and ab C represents the terminal voltage waveform of the three phases of the motor uv W.
In fig. 2, six steps of commutation are respectively: STEP1: b+c-, STEP2: a+c-, STEP3: a+b-, STEP4: c+b-, STEP5: c+a-, STEP6: B+A-, the six steps represent a commutation complete cycle, and T1, T2, T3, T4, T5, T6 represent commutation cycle times.
Fig. 2 defines variables used by the commutation initiation algorithm process, which are described as follows:
demag zone: true degaussing event
CommuT: software estimated commutation period
DemagT: demagnetizing time
Advanced: advance angle time
Zc_scant: zero crossing scan timeout time
Zc_time: zero crossing time
Other description of variables used:
step: number of commutation steps
Zero_type: ascending or descending (up or down)
V_phaseu: u-phase voltage
V_phasev: v-phase voltage
V_phasew: w-phase voltage
V_Bus: bus voltage
Zerocross_flag: zero crossing event flag, bool type variable
Zc_fail_flag: no qualified zero point is detected, and the commutation is overtime
Bemf_zero_err: difference between phase voltage and V_Bus/2
Bemf_peak_err: maximum value of phase voltage and V_Bus/2 difference
StartUp_CommuFail_CNT: a commutation failure count is started.
The commutation TABLE commu_table [ Step ] is calculated and sets of dimensions 1x32, the commutation TABLE storing count values of timeout times for 32 commutations (CNT based on timer 0). The commutation time of 32 times is calculated by a motor voltage equation, a torque equation and a transmission equation through solving an overrun equation of the commutation period time, and the commutation period time is determined by motor parameters and loads.
Detailed Description
As described in fig. 1 and 2, the overall start-up process is divided into two phases: an S1 external synchronization phase and an S2 transitional synchronization phase.
S1 outer synchronization stage: 14 times of commutation and external synchronous acceleration, at the moment, the commutation is performed according to the time timeout of the commutation table, and a counter electromotive force zero crossing signal is not used.
S2, transition synchronization stage: and 18 times of commutation and a transitional synchronization stage, wherein the stage mainly relies on detecting the counter electromotive force zero-crossing commutation and immediately executing the locked-rotor fault detection after 32 times of commutation.
The following steps are detailed descriptions of the start-up process of fig. 1, and are specifically described below.
The first step: the pwm module is configured and enabled, the pwm period is 50us, and the pwm period interrupt is enabled,
the commutation Timer0 is configured and enabled, with a Timer0 period of 30ms.
And a second step of: judging whether the startup mark motor_startup is 1, immediately starting to enter the next step if the startup mark motor_startup is 1, entering the standby step if the startup mark motor_startup is 0, and not executing the following steps.
And a third step of: the commutation TABLE COMMU_TABLE [ Step ] is loaded, 13 commutations are performed, the rotor is accelerated in advance, and the process records BEMF_Peak_Err of each Step and temporarily stores the BEMF_Peak [ Step ] array.
Fourth step: when the 13 th commutation is completed, the BEMF_Peak [ step ] array values are traversed and compared with STALL_THD,
BEMF_Peak [ step ] > STALL_THD has a comparison value of 1, start_Start_Cnt++;
BEMF_Peak [ step ] < STALL_THD comparison value of 0, start_Start_Cnt-;
fifth step: if Start_Start_Cnt > 4, the load is too large or the rotor is blocked, the phase change is continued according to the COMMU_TABLE [ Step ] TABLE in time out at the moment, when the phase change is completed for 32 times, the phase change fault is reported at the moment when the phase change is completed, the fault mode is entered, and the following steps are not executed.
Sixth step: if start_state_cnt < =4, it indicates that there is a significant fluctuation in back emf, at which point the next stage S2 can be smoothly entered.
Seventh step: the 14 th commutation is rotor accelerating phase, and the commutation is continuously carried out according to the COMMUTABLE Step TABLE overtime, the commutation overtime time of the phase is 1/4 of the 13 th commutation, and the aim is to keep the included angle between the stator and the rotor magnetomotive force within the range of 60-120 degrees.
Timer0 Timer overflow interrupt trigger, 14 th commutation is finished, and at this time, the variable time for updating the next phase is set as
DemagT = COMMU_TABLE[14]/8；
AdvanceT = ZC_Time/2；
ZC_ScanT = COMMU_TABLE[5]；
The time represented by COMMUTABLE [5] is 15ms.
Eighth step: at this time, 15 th commutation is entered, the back electromotive force Zero-crossing signal is detected from this step and the commutation is performed according to this signal, and the bemf_zero_err variable is detected and recorded at each pwm interrupt.
Because of the uncertainty of the load, the degaussing time setting of this phase is very short, so that there is a possibility of incomplete masking of the degaussing event, for which purpose it is necessary to determine the true value of the following relation
(phase voltage amplitude > =v_bus/2) & & (phase voltage amplitude < =v_bus-3)
Or (phase voltage amplitude < = v_bus/2) & & (phase voltage amplitude > = 3)
These two decisions are based on the zero type and are also performed in each pwm interrupt, with the true result being stored in the zerocross_flag variable.
When zerocross_flag=1, the effective zero point is detected, calculation is performed:
Commu_T = ZC_Time + AdvanceT；
ZC_Fail_flag =0；
the cycle count register of Timer0 is updated to (CNT 0+ advanced). The Timer0 Timer is updated, at this time, the Timer0 period counting overflow interrupt trigger is waited, when the 15 th phase change is ended due to the Timer0 interrupt trigger, the variable time for updating the next phase is set at this time:
DemagT = Commu_T/8；
AdvanceT = ZC_Time/2；
ZC_ScanT = COMMU_TABLE[5]；
the time represented by COMMUTABLE [5] is 15ms.
When zerocross_flag=0, and no effective Zero point is detected, zero crossing scanning is overtime, waiting for Timer0 period counting overflow interrupt trigger, when Timer0 interrupt trigger, finishing 15 th phase change, calling the BEMF_zero_Err value of the last pwm period of 15 th phase change, and executing calculation:
Commu_T = ABS(BEMF_Zero_Err)* COMMU_TABLE[1]/V_Bus*2；
ZC_Fail_flag =1；
setting variable time for updating the next phase:
DemagT = Commu_T/8；
AdvanceT = Commu_T /2；
ZC_ScanT = COMMU_TABLE[2]；
the time represented by COMMUTABLE 2 is 20ms.
Finally, according to the value of ZC_Fail_flag, calculating:
if zc_fail_flag=1, startup_commufail_cnt++;
ninth step: at this time, 16 times of commutation are entered, and the 15 th commutation process is repeated from 16 to 32 times of commutation.
Tenth step: when 32 times of commutation are finished, judging the StartUp_CommuFail_CNT variable
If StartUp_CommuFail_CNT > =4, the start fails and a stall fault is reported.
If StartUp_CommuFail_CNT < 4, the start-up is successful and the commutation is continued.
The above examples are preferred embodiments of the present invention, but the present invention is not limited to the above examples, and any other modifications without departing from the spirit and principle of the present invention should be equivalent to the above examples, and are included in the scope of the present invention.
Claims (2)
1. The utility model provides a permanent magnet synchronous motor high reliability starting method based on position control, six steps of commutation strategies based on back electromotive force zero crossing are adopted in motor control, adopts software drive open loop start mode, and back electromotive force zero crossing signal is obtained by software through the comparison of UVW three-phase terminal voltage and bus_voltage/2 of AD sampling, characterized by:
the start-up procedure is divided into two phases: an outer synchronization phase and a transition synchronization phase, which perform a total of 32 commutation;
an external synchronization stage, in which the rotor is accelerated in advance for 14 times in total, for phase inversion;
the 14 th commutation timeout time is 1/4 of the 13 th commutation, the phase is a commutation process with fixed duration, the commutation is accelerated, the included angle between the magnetomotive force of the stator and the magnetomotive force of the rotor is reduced from 180 degrees, and finally, the included angle between the magnetomotive force vectors of the stator and the rotor is ensured to be kept within the range of 60-120 degrees;
a transition synchronization stage, wherein the stage has obvious back electromotive force, reads zero crossing points, and commutates according to zero crossing signals, and the stage is totally 18 commutates;
in the stage, according to the relation between the phase voltage and the bus voltage of 1/2, the authenticity of zero crossing signals of each phase is judged so as to shield zero misjudgment caused by uncertainty of demagnetization time;
when the 15 th commutation scan reaches a qualified zero crossing signal: the advance angle time is set to be 1/2 of the zero crossing time of the current commutation period; setting the demagnetizing time to be 1/8 of the 14 th commutation period time; setting the zero crossing scanning timeout time to 15ms;
when the 15 th commutation does not scan for a qualified zero crossing signal and the zero crossing scan times out: updating commutation period time according to the amplitude of the back electromotive force captured by the last commutation ending point, starting the commutation failure count to be increased by 1, and executing the following three choices by software:
the time of the advance angle is changed according to the last commutation period time, so as to estimate the optimal commutation point;
changing the demagnetizing time according to the last commutation period time;
the pwm duty cycle is changed to adapt to the load change according to the last commutation period time, so that the load adaptability is improved;
the zero type of the 15 th phase-change zero-crossing signal is a rising edge, and the zero-crossing scanning timeout time is longer than 15ms, so that enough zero-crossing detection time is ensured to adapt to load change and change of the synchronous effect;
the reliability of successful starting is ensured through 15 th commutation, and the 15 th commutation process is repeated from 16 th to 32 th commutation; when the 32 times of commutation are finished, when the commutation starting failure count is more than or equal to 4 times, the commutation starting failure is judged, and a locked-up fault is reported; and when the commutation starting failure count is smaller than 4 times, starting is successful, and commutation is continuously executed.
2. The method for starting the permanent magnet synchronous motor with high reliability based on position control according to claim 1, wherein the method comprises the following steps: the pwm period is 50us, and zero point detection and judgment are performed in the pwm period interrupt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210174702.6A CN114362623B (en) | 2022-02-25 | 2022-02-25 | Permanent magnet synchronous motor high-reliability starting method based on position control |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210174702.6A CN114362623B (en) | 2022-02-25 | 2022-02-25 | Permanent magnet synchronous motor high-reliability starting method based on position control |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114362623A CN114362623A (en) | 2022-04-15 |
| CN114362623B true CN114362623B (en) | 2023-06-30 |
Family
ID=81093102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210174702.6A Active CN114362623B (en) | 2022-02-25 | 2022-02-25 | Permanent magnet synchronous motor high-reliability starting method based on position control |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114362623B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103051262A (en) * | 2012-12-26 | 2013-04-17 | 广西师范大学 | Brushless direct current motor electronic speed governor based on STM32 |
| CN105356796A (en) * | 2015-12-02 | 2016-02-24 | 国家电网公司 | Permanent magnet brushless DC Motor position sensorless control system |
| CN110535378A (en) * | 2019-08-27 | 2019-12-03 | 江苏科技大学 | Brshless DC motor high-precision changes facies-controlled method and system |
| CN113364368A (en) * | 2021-05-21 | 2021-09-07 | 联合汽车电子有限公司 | Motor starting method and readable storage medium |
-
2022
- 2022-02-25 CN CN202210174702.6A patent/CN114362623B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103051262A (en) * | 2012-12-26 | 2013-04-17 | 广西师范大学 | Brushless direct current motor electronic speed governor based on STM32 |
| CN105356796A (en) * | 2015-12-02 | 2016-02-24 | 国家电网公司 | Permanent magnet brushless DC Motor position sensorless control system |
| CN110535378A (en) * | 2019-08-27 | 2019-12-03 | 江苏科技大学 | Brshless DC motor high-precision changes facies-controlled method and system |
| CN113364368A (en) * | 2021-05-21 | 2021-09-07 | 联合汽车电子有限公司 | Motor starting method and readable storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114362623A (en) | 2022-04-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5969491A (en) | Detection of instantaneous position of the rotor of a brushless DC motor driven in a tripolar mode | |
| US7652441B2 (en) | Method and system for starting a sensorless motor | |
| EP3849073A1 (en) | Catch spin method for permanent magnet synchronous motor with sensorless field oriented control | |
| CN105453412B (en) | For the controller of brushless motor | |
| WO2020193957A1 (en) | A method of determining a position of a rotor of a brushless permanent magnet motor | |
| CN113131805A (en) | Control device and method of brushless direct current motor | |
| EP0881761B1 (en) | A controller for a brushless DC motor without a position sensor | |
| KR100289496B1 (en) | sensorlee speed control method of high speed motor | |
| EP0892489B1 (en) | Detection of instantaneous position of the rotor of a brushless DC motor driven in a tripolar mode | |
| Damodharan et al. | Indirect back-EMF zero crossing detection for sensorless BLDC motor operation | |
| CN105490612B (en) | Method for controlling position-less sensor of switched reluctance motor and system | |
| Kan et al. | Adaptive soft starting method with current limit strategy for sensorless BLDC motors | |
| CN114362623B (en) | Permanent magnet synchronous motor high-reliability starting method based on position control | |
| Wang et al. | A novel sensorless control method for brushless DC motor | |
| Iwaji et al. | Position-sensorless control method at low speed for permanent magnet synchronous motors using induced voltage caused by magnetic saturation | |
| CN115395835A (en) | Brushless direct current motor commutation accurate detection method | |
| Yao et al. | Line voltage difference integral method of commutation error adjustment for sensorless brushless DC motor | |
| Du et al. | A new starting method for 12/8-pole doubly salient permanent-magnet motors without position sensor | |
| Lu et al. | New design for sensorless bldc motor using half-bridge driver circuit | |
| KR101684807B1 (en) | Lead Angle Controller | |
| Hu et al. | A new start method for sensorless brushless DC motor based on pulse injection | |
| Nair et al. | A novel back-EMF detection scheme based sensorless control of permanent magnet brushless DC motor drive | |
| CN117937992A (en) | Brushless motor operation control driving method | |
| Qiu et al. | A Full-speed range sensorless control scheme of brushless DC motor based on saliency effects | |
| Yousfi | Encoderless PM brushless drive for electric vehicle traction |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |