CN114006561B - Abnormal detection method for locked-rotor state of brushless direct current motor under sensorless square wave control working condition - Google Patents
Abnormal detection method for locked-rotor state of brushless direct current motor under sensorless square wave control working condition Download PDFInfo
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- CN114006561B CN114006561B CN202111361053.2A CN202111361053A CN114006561B CN 114006561 B CN114006561 B CN 114006561B CN 202111361053 A CN202111361053 A CN 202111361053A CN 114006561 B CN114006561 B CN 114006561B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/08—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors
- H02H7/093—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against increase beyond, or decrease below, a predetermined level of rotational speed
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/64—Electric machine technologies in electromobility
Abstract
A method for detecting abnormal locked-rotor state of a brushless DC motor under a square wave control working condition without a sensor comprises the steps of collecting two-phase counter-potential signals; acquiring and calculating a counter potential zero crossing point according to the obtained counter potential signal; calculating the maximum value, the minimum value and the average value of the period of the latest 6 zero crossing points according to the acquired counter potential zero crossing point information, carrying out reference comparison on the counter potential zero crossing point period, and judging whether the counter potential zero crossing point is in an abnormal state or not; judging a locked rotor detection fault factor value according to the counter potential zero crossing reference comparison result; and judging whether to trigger a locked rotor shutdown event according to the locked rotor detection fault factor value. The abnormal detection method of the locked rotor state can be realized on the existing brushless direct current motor driving hardware structure, and has good adaptability; the method has simple step structure and is easy to realize. The abnormal detection method for the locked rotor state can reliably and effectively detect the locked rotor event no matter in the starting stage or the normal operation stage.
Description
Technical Field
The invention relates to the field of brushless direct current motor control, in particular to a method for detecting abnormal locked-rotor state of a brushless direct current motor under a square wave control working condition without a sensor.
Background
Along with the continuous improvement of the automation degree of automobiles, the motor is also widely applied to automobiles. Whether it is a conventional fuel car or a new energy car, the motor plays an increasingly important role as an actuator. The large family of automobile motors has a class of motors called fluid control motors, including various fans, blowers, water pumps, oil pumps, compressors and the like. Many of these motors currently use brushless dc motors or during switching to brushless dc motors. The brushless DC motor has the characteristics of high efficiency and high reliability, and the fluid motor is hardly operated in a low-speed area, so that the sensorless control of the brushless DC motor is particularly suitable for the applications of automobiles.
When the motor is at zero speed, the torque is still output, and the stalling occurs. There are many reasons for motor stalling, including mechanical or man-made, such as: the rotor and the stator are blocked by contact, the driven equipment is blocked, the motor cannot be driven due to too large equipment load, and the like, so that the locked rotor is caused. Because no sensor signal is connected, once external resistance or huge sudden load change is encountered, the system can enter a locked-rotor state. In the locked-rotor state in this square wave control, the motor simply shakes in place and consumes current, and the system is in an abnormal state. Maintaining such a state for a long period of time is certainly harmful.
Therefore, a method for realizing locked rotor detection is needed for the brushless direct current motor under the condition of no-sensor square wave control.
Disclosure of Invention
The invention provides a method for detecting abnormal locked-rotor state of a brushless direct current motor under a sensorless square wave control working condition, which aims to solve the problem that the mode of detecting abnormal locked-rotor state of the brushless direct current motor under the sensorless square wave control working condition in the prior art is not better.
A method for detecting abnormal locked-rotor state of a brushless DC motor under a sensorless square wave control working condition comprises the following steps:
step one: collecting two opposite potential signals;
step two: acquiring and calculating a counter potential zero crossing point according to the counter potential signal obtained in the first step;
step three: calculating the maximum value, the minimum value and the average value of the period of the last 6 zero crossing points according to the counter potential zero crossing point information obtained in the second step, and carrying out counter potential zero crossing point period reference comparison to judge whether the counter potential zero crossing point information belongs to an abnormal state or not;
step four: judging a locked rotor detection fault factor value according to the counter potential zero crossing reference comparison result in the step three;
step five: and judging whether to trigger a locked-rotor shutdown event according to the locked-rotor detection fault factor value obtained in the step four.
In the first step, the reconstruction calculation of the back electromotive force signals is realized by collecting any two-phase electric signals in the three-phase back electromotive force electric signals.
Further, the digital signals obtained by collecting two opposite potential signals and converting the two opposite potential signals by the two comparators and the two ADC are connected into the control module.
In the second step, the counter potential zero crossing point obtaining and calculating is specifically that the controller obtains the counter potential zero crossing point by comparing the digital signal value after ADC conversion with the neutral potential value, and calibrates the time information of the counter potential zero crossing point, and calculates the time difference value with the last counter potential zero crossing point to obtain a zero crossing point period.
Further, in the third step, the maximum value and the minimum value of the counter potential zero crossing period are found out by comparing the last 6 counter potential zero crossing periods, and then the average value of the 6 zero crossing periods is calculated; comparing the zero-crossing period average value with half of the maximum value and 2 times of the zero-crossing period average value and the minimum value, and if the zero-crossing period average value is smaller than half of the maximum value or larger than 2 times of the minimum value, the zero-crossing period average value belongs to an abnormal state; if the minimum value of the zero crossing period is smaller than the minimum value of the set block detection commutation period, the abnormal state is also included.
Further, in the fourth step, the value of the locked rotor detection fault factor is associated with an abnormal state, and if the abnormal state occurs, the value of the locked rotor detection fault factor is accumulated; if no abnormal state exists, the value of the locked rotor detection fault factor is reduced.
Further, in the step five, judging whether a locked rotor stopping event is triggered to be related to the locked rotor detection fault factor value in the step four, wherein the locked rotor stopping event is triggered to be related to the locked rotor detection fault factor value in the step four, the default value of the locked rotor factor is 0, when the locked rotor stopping event is triggered, the locked rotor factor is increased by 1, and when the locked rotor stopping event is eliminated, the locked rotor factor is reduced by 1; if the value of the locked rotor detection fault factor is more than or equal to 3, triggering a locked rotor stopping event; if the value of the locked rotor detection fault factor is smaller than 3, the motor control program is normally executed.
The invention has the beneficial effects that:
1. the method for detecting the abnormal locked rotor state in the technical scheme of the invention can be realized on the existing brushless direct current motor driving hardware structure, and has better adaptability.
2. The method for detecting the abnormal locked rotor state in the technical scheme is simple in steps and easy to realize. The abnormal detection method for the locked rotor state can reliably and effectively detect the locked rotor event no matter in the starting stage or the normal operation stage.
Drawings
Fig. 1 is a flowchart of a method for detecting abnormal locked rotor state of a brushless dc motor according to an embodiment of the present invention.
Fig. 2 is a system configuration block diagram of a method for detecting abnormal locked rotor state of a brushless dc motor according to an embodiment of the present invention.
Fig. 3 is a flowchart of detection and judgment of a locked rotor detection failure in an embodiment of the present invention.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the attached drawings.
The invention provides a method for detecting abnormal locked-rotor state of a brushless DC motor under the working condition of sensorless square wave control, as shown in figure 2, optionally comprising the following steps: three-phase stator winding, dc-to-ac converter module, back electromotive force collection module, the control module of brushless DC motor, wherein: the inverter module is connected with a three-phase stator winding of the brushless direct current motor and is used for driving the motor and feeding back phase line voltage and current information; the back electromotive force acquisition module is connected with the inverter module and is used for acquiring three-phase back electromotive force; the control module is connected with the counter potential acquisition module and is used for detecting and calculating zero crossing point information of the counter potential.
The invention provides a method for detecting abnormal locked-rotor state of a brushless direct current motor under a square wave control working condition without a sensor, which is shown in figure 2 and comprises the following steps:
step S10: collecting three opposite potential signals;
according to the symmetrical three-phase brushless direct current motor, the sum of all counter potential voltage signals is zero, and the three-phase counter potential signals can be collected and replaced by the two-phase counter potential electric signals. The digital signals converted by the two paths of comparators and the two paths of ADC are accessed into the control module.
Step S20: and (3) acquiring and calculating a counter potential zero crossing point according to the counter potential signal obtained in the step S10.
In step S20, the counter potential zero crossing point is obtained and calculated, the controller obtains the counter potential zero crossing point by comparing the digital signal value converted by the ADC with the neutral potential value, and calibrates the time information thereof, calculates the time difference value with the last counter potential zero crossing point, and obtains a zero crossing point period.
Step S30: and (3) calculating the maximum value of the latest 6 zero crossing periods to be assigned to MAX, the minimum value to be assigned to MIN and the average value to be assigned to AVER according to the counter potential zero crossing information obtained in the step S30, and comparing the counter potential zero crossing period reference.
In step S30, the maximum value, the minimum value and the average value of the period of the last 6 zero crossing points are calculated, the maximum value and the minimum value are found out by comparing the period of the last 6 counter potential zero crossing points, and the average value of the 6 zero crossing points is calculated. Comparing counter potential zero crossing period reference, namely comparing half of a zero crossing period average value with a maximum value and 2 times of the zero crossing period average value with a minimum value, and if the zero crossing period average value is smaller than half of the maximum value or larger than 2 times of the minimum value, the counter potential zero crossing period reference belongs to an abnormal state; if the minimum value of the zero crossing period is smaller than the minimum value of the set block detection commutation period, the abnormal state is also included.
Step S40: and judging the value of the locked rotor detection fault factor according to the counter potential zero crossing reference comparison result in the step S30.
As shown in fig. 3, in step S40, the stall detection failure factor value is associated with the abnormal state in step S30, and if an abnormal state occurs once in the comparison, the stall detection failure factor value θ is increased by 1; if no abnormal state occurs in this comparison, the stall detection failure factor value θ is reduced by 1.
Step S50: and judging whether to trigger a locked-rotor shutdown event according to the locked-rotor detection fault factor value obtained in the step S40.
As shown in fig. 3, in step S50, it is determined whether or not the locked-rotor shutdown event is triggered in association with the locked-rotor detection fault factor value in step S40, the locked-rotor shutdown event is triggered in association with the locked-rotor detection fault factor value in step four, the default value of the locked-rotor factor value θ is 0, when the locked-rotor shutdown event is triggered, the locked-rotor factor value θ is increased by 1, and when the locked-rotor shutdown event is eliminated, the locked-rotor factor value θ is decreased by 1. If the value theta of the locked rotor detection fault factor is more than or equal to 3, triggering a locked rotor stopping event; if the value theta of the locked rotor detection fault factor is smaller than 3, the motor control program is normally executed.
The above description is merely of preferred embodiments of the present invention, and the scope of the present invention is not limited to the above embodiments, but all equivalent modifications or variations according to the present disclosure will be within the scope of the claims.
Claims (4)
1. A method for detecting abnormal locked-rotor state of a brushless direct current motor under a sensorless square wave control working condition is characterized by comprising the following steps of: the method comprises the following steps:
step one: collecting two opposite potential signals;
step two: acquiring and calculating a counter potential zero crossing point according to the counter potential signal obtained in the first step;
step three: calculating the maximum value, the minimum value and the average value of the period of the last 6 zero crossing points according to the counter potential zero crossing point information obtained in the second step, and carrying out counter potential zero crossing point period reference comparison to judge whether the counter potential zero crossing point information belongs to an abnormal state or not;
step three, finding out the maximum value and the minimum value of the counter potential zero crossing period by comparing the last 6 times, and calculating the average value of the 6 zero crossing periods; comparing the zero-crossing period average value with half of the maximum value and 2 times of the zero-crossing period average value and the minimum value, and if the zero-crossing period average value is smaller than half of the maximum value or larger than 2 times of the minimum value, the zero-crossing period average value belongs to an abnormal state; if the minimum value of the zero crossing period is smaller than the minimum value of the set block detection phase conversion period, the state is abnormal;
step four: judging a locked rotor detection fault factor value according to the counter potential zero crossing reference comparison result in the step three;
step four, associating the locked rotor detection fault factor value with an abnormal state, and accumulating the locked rotor detection fault factor value if the abnormal state occurs; if no abnormal state exists, the value of the locked rotor detection fault factor is reduced;
step five: judging whether to trigger a locked-rotor shutdown event according to the locked-rotor detection fault factor value obtained in the step four;
in the fifth step, the triggering locked rotor stopping event is related to the locked rotor detection fault factor value in the fourth step, the default value of the locked rotor detection fault factor is 0, when the locked rotor stopping event is triggered, the locked rotor detection fault factor is increased by 1, and when the locked rotor stopping event is eliminated, the locked rotor detection fault factor is decreased by 1; if the value of the locked rotor detection fault factor is more than or equal to 3, triggering a locked rotor stopping event; if the value of the locked rotor detection fault factor is smaller than 3, the motor control program is normally executed.
2. The method for detecting abnormal locked-rotor state of a brushless direct current motor under the condition of sensorless square wave control according to claim 1, wherein the method comprises the following steps: in the first step, the two-phase counter potential electric signals are collected, and the reconstruction calculation of the counter potential signals is realized by collecting any two-phase electric signals in the three-phase counter potential electric signals.
3. The method for detecting abnormal locked-rotor state of a brushless direct current motor under the condition of sensorless square wave control according to claim 2, wherein the method comprises the following steps: and the digital signals converted by the two comparators and the two ADC are connected into the control module.
4. The method for detecting abnormal locked rotor state of a brushless direct current motor under a sensorless square wave control condition according to claim 3, wherein the method comprises the following steps: in the second step, the counter potential zero crossing point is obtained and calculated specifically, the controller obtains the counter potential zero crossing point by comparing the digital signal value after ADC conversion with the neutral potential value, and calibrates the time information thereof, calculates the time difference value with the last counter potential zero crossing point, and obtains a zero crossing point period.
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