CN110890740A - Motor phase loss detection method - Google Patents

Motor phase loss detection method Download PDF

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Publication number
CN110890740A
CN110890740A CN201911129569.7A CN201911129569A CN110890740A CN 110890740 A CN110890740 A CN 110890740A CN 201911129569 A CN201911129569 A CN 201911129569A CN 110890740 A CN110890740 A CN 110890740A
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sequence
phase
sampling
values
value
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丛凤龙
管博
殷浩
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Gezhi Control Intelligent Power Technology (shanghai) Co Ltd
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Gezhi Control Intelligent Power Technology (shanghai) Co Ltd
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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
    • H02H7/09—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 over-voltage; against reduction of voltage; against phase interruption
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
    • G01R29/16—Measuring asymmetry of polyphase networks
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/34—Testing dynamo-electric machines
    • G01R31/343—Testing dynamo-electric machines in operation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00—Details of emergency protective circuit arrangements
    • H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means

Abstract

The invention relates to the field of protection devices for preventing phase failure of motors, in particular to a motor phase failure detection method which is characterized by being sequentially implemented according to the following steps of ① sampling, ② filtering and ③ phase failure judgment.

Description

Motor phase loss detection method
Technical Field
The invention relates to the field of protection devices for preventing phase failure of motors, in particular to a motor phase failure detection method.
Background
At present, most of the open-phase detection modes of the motor are based on phase current detection, and the method generally does not consider the problem of data processing and the problem of external interference or interference in the sampling process. The detection result is unreliable, and the motor phase loss protection is influenced.
Disclosure of Invention
The invention discloses a motor open-phase detection method, which aims to overcome the defects of the prior art and provide an open-phase protection device with strong anti-interference performance and high detection precision.
The invention achieves the purpose by the following technical scheme:
a motor phase loss detection method is characterized in that a three-phase input end of a three-phase permanent magnet synchronous motor is respectively connected with a three-phase power supply through a lead, a current sensor is respectively connected with the lead of each phase in series, and the three current sensors are all connected with a controller through signal wires, and the method comprises the following steps: the method is implemented in sequence according to the following steps:
① sampling, wherein three current sensors respectively sample phase A current Ia, phase B current Ib and phase C current Ic of three-phase power supply, and the operating frequency of space vector modulation (foc) controlled by three-phase permanent magnet synchronous motor is set as ffocThen each current sampling period TfocIs composed of
Figure BDA0002277909350000011
Each calculation period T of phase currentfCalculated as follows:
Figure BDA0002277909350000012
(1) in the formula:
n is the actual rotating speed of the motor after per unit,
Nbaseis a reference value of the rotating speed in the software,
p is the number of pole pairs of the motor;
unlike other implementations, which require integration over the entire phase current calculation period, the algorithm only needs half of the phase current calculation period to obtain the peak value (peak or trough) because of the square sum,
the phase currents Ia, Ib and Ic obtained in each sampling period are divided intoRespectively squaring to obtain
Figure BDA0002277909350000013
And
Figure BDA0002277909350000014
respectively obtained in each half phase current calculation period
Figure BDA0002277909350000021
And
Figure BDA0002277909350000022
maximum value of
Figure BDA0002277909350000023
And
Figure BDA0002277909350000024
② filtering, in order to filter out the sampling problem caused by interference, a pair of recursive average filtering and median filtering algorithm is adopted
Figure BDA0002277909350000025
And
Figure BDA0002277909350000026
respectively carrying out the filtering treatment on the raw materials,
the recursive average filtering algorithm is also called as a sliding average filtering algorithm, namely, N continuous sampling values are regarded as a sequence, the length of the sequence is fixed to N, a new sampling value is sampled at each time and is placed at the tail end of the sequence, the sampling value at the head of the original sequence is removed, thus the length of the sequence is always kept fixed to N by a method of removing the sequence from the sampling values which enter the sequence first, and N data in the queue are subjected to arithmetic average calculation to obtain a sequence average value;
the median filtering algorithm can also be an anti-pulse interference filtering algorithm, continuously samples N sequences and obtains N sequence average values, removes the maximum and minimum two sequence average values, and obtains an arithmetic average value which is a filtering result value for the rest N-2 sequence average values;
specifically, the method comprises the following steps: setting:
the sequence obtained in the 1 st sampling period is L (1), the sampling values in the initial state of L (1) are { L (1), L (2), … …, L (N) }, and the arithmetic average of the N sampling values L (1) -L (N) is carried out to obtain
Figure BDA0002277909350000027
Continuing sampling to obtain a new sampling value L (N +1), adding L (N +1) into the L (1) sequence and locating at the tail end, removing the L (1) sequence from the L (1) sequence to obtain a new sequence L (2) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (2) -L (N +1) to obtain
Figure BDA0002277909350000028
……，
Continuing sampling to obtain a new sampling value L (N + i), adding L (N + i) into the sequence L (i) and locating at the tail end, removing the sequence L (i) from the sequence L (i) so as to obtain a new sequence L (i +1) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (i +1) -L (N + i) to obtain an arithmetic average value
Figure BDA0002277909350000029
……，
Continuing sampling to obtain a new sampling value L (2N-1), adding L (2N-1) into the L (2N-1) sequence and locating at the tail end, removing the L (2N-1) sequence from L (2N-1) so as to obtain a new sequence L (2N) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (N) to L (2N-1) to obtain
Figure BDA00022779093500000210
Figure BDA00022779093500000211
……、
Figure BDA00022779093500000212
… … and
Figure BDA00022779093500000213
forming a sequence L (N) containing N average values, eliminating the maximum value and the minimum value in the sequence L (N), and calculating the arithmetic average of the rest N-2 average values
Figure BDA00022779093500000214
The result value is the filtering result value;
wherein: n is a positive integer not less than 5, i is a positive integer and i belongs to (1, N);
filtered
Figure BDA0002277909350000031
And
Figure BDA0002277909350000032
are respectively marked as
Figure BDA0002277909350000033
And
Figure BDA0002277909350000034
in order to eliminate the error judgment in the static state of the motor, a phase current judgment threshold I is setDWhen is coming into contact with
Figure BDA0002277909350000035
And
Figure BDA0002277909350000036
at least one of the three values is greater than IDWhen the phase is short, the phase failure judgment is carried out;
③ phase loss judgment, first judgment
Figure BDA0002277909350000037
And
Figure BDA0002277909350000038
the maximum and minimum of these three values are noted as
Figure BDA0002277909350000039
And
Figure BDA00022779093500000310
order to
Figure BDA00022779093500000311
And comparing the I with a phase current judgment threshold D, if the I is smaller than the D, considering that the motor is in phase failure, and immediately stopping the operation of the three-phase permanent magnet synchronous motor by the controller after judging that the motor is in phase failure so as to prevent the three-phase permanent magnet synchronous motor and the controller from being damaged due to unbalanced three-phase operation.
The motor open-phase detection method is characterized in that in the step ①, ffocTaking 10 kHz;
at step ②, N is not less than 10.
Although the phase failure is judged by detecting the phase current, the invention mainly solves the problems caused by external interference and sampling interference, judges the phase failure by the square sum of the phase current and has the advantages of strong anti-interference performance and high detection precision
Drawings
Fig. 1 is a schematic diagram of the connection of the present invention.
Detailed Description
The invention is further illustrated by the following specific examples.
Example 1
A motor phase loss detection method, as shown in fig. 1: the three-phase input end of a three-phase permanent magnet synchronous motor 1 is respectively connected with a three-phase power supply 2 by leads, a current sensor 3 is respectively connected in series on the lead of each phase, the three current sensors 3 are all connected with a controller 4 by signal wires, and the method is implemented in sequence according to the following steps:
① sampling, three current sensors 3 respectively sample phase A current Ia, phase B current Ib and phase C current Ic of the three-phase power supply 2, and the operating frequency of space vector modulation (foc for short) controlled by the three-phase permanent magnet synchronous motor 1 is set as ffocThen each current sampling period TfocIs composed of
Figure BDA00022779093500000312
Such as ffocTaking 10kHz, then Tfoc0.1ms, phase current each calculation period TfCalculated as follows:
Figure BDA00022779093500000313
(1) in the formula:
n is the actual rotating speed of the motor after per unit,
Nbaseis a reference value of the rotating speed in the software,
p is the number of pole pairs of the motor;
unlike other implementations that require integration over the entire phase current calculation period, this embodiment, because of the sum of squares, only half of the phase current calculation period is needed to obtain the peak value (peak or trough),
respectively squaring the phase currents Ia, Ib and Ic obtained in each sampling period to obtain
Figure BDA0002277909350000041
And
Figure BDA0002277909350000042
respectively obtained in each half phase current calculation period
Figure BDA0002277909350000043
And
Figure BDA0002277909350000044
maximum value of
Figure BDA0002277909350000045
And
Figure BDA0002277909350000046
② filtering, in order to filter out the sampling problem caused by interference, a pair of recursive average filtering and median filtering algorithm is adopted
Figure BDA0002277909350000047
And
Figure BDA0002277909350000048
respectively carrying out the filtering treatment on the raw materials,
the recursive average filtering algorithm is also called as a sliding average filtering algorithm, namely, N continuous sampling values are regarded as a sequence, the length of the sequence is fixed to N, a new sampling value is sampled at each time and is placed at the tail end of the sequence, the sampling value at the head of the original sequence is removed, thus the length of the sequence is always kept fixed to N by a method of removing the sequence from the sampling values which enter the sequence first, and N data in the queue are subjected to arithmetic average calculation to obtain a sequence average value;
the median filtering algorithm can also be an anti-pulse interference filtering algorithm, continuously samples N sequences and obtains N sequence average values, removes the maximum and minimum two sequence average values, and obtains an arithmetic average value which is a filtering result value for the rest N-2 sequence average values;
specifically, the method comprises the following steps: setting:
the sequence obtained in the 1 st sampling period is L (1), the sampling values in the initial state of L (1) are { L (1), L (2), … …, L (N) }, and the arithmetic average of the N sampling values L (1) -L (N) is carried out to obtain
Figure BDA0002277909350000049
Continuing sampling to obtain a new sampling value L (N +1), adding L (N +1) into the L (1) sequence and locating at the tail end, removing the L (1) sequence from the L (1) sequence to obtain a new sequence L (2) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (2) -L (N +1) to obtain
Figure BDA00022779093500000410
……，
Continuing sampling to obtain a new sampling value L (N + i), adding L (N + i) into the sequence L (i) and locating at the tail end, removing the sequence L (i) from the sequence L (i) so as to obtain a new sequence L (i +1) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (i +1) -L (N + i) to obtain an arithmetic average value
Figure BDA00022779093500000411
……，
Continuing sampling to obtain a new sampling value L (2N-1), adding L (2N-1) into the L (2N-1) sequence and locating at the tail end, removing the L (2N-1) sequence from L (2N-1) so as to obtain a new sequence L (2N) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (N) to L (2N-1) to obtain
Figure BDA00022779093500000412
Figure BDA0002277909350000051
……、
Figure BDA0002277909350000052
… … and
Figure BDA0002277909350000053
forming a sequence L (N) containing N average values, eliminating the maximum value and the minimum value in the sequence L (N), and calculating the arithmetic average of the rest N-2 average values
Figure BDA0002277909350000054
The result value is the filtering result value;
wherein: n is a positive integer not less than 10, i is a positive integer and i belongs to (1, N);
filtered
Figure BDA0002277909350000055
And
Figure BDA0002277909350000056
are respectively marked as
Figure BDA0002277909350000057
And
Figure BDA0002277909350000058
to eliminate erroneous determination in a stationary state of a motor, a phase current is setFlow decision threshold IDWhen is coming into contact with
Figure BDA0002277909350000059
And
Figure BDA00022779093500000510
at least one of the three values is greater than IDWhen the phase is short, the phase failure judgment is carried out;
③ phase loss judgment, first judgment
Figure BDA00022779093500000511
And
Figure BDA00022779093500000512
the maximum and minimum of these three values are noted as
Figure BDA00022779093500000513
And
Figure BDA00022779093500000514
order to
Figure BDA00022779093500000515
And comparing the I with a phase current judgment threshold D, if the I is smaller than the D, considering that the motor is in phase failure, and immediately stopping the operation of the three-phase permanent magnet synchronous motor 1 by the controller 4 after judging that the motor is in phase failure so as to prevent the three-phase permanent magnet synchronous motor 1 and the controller 4 from being damaged due to unbalanced three-phase operation.

Claims (2)

1. The utility model provides a motor phase failure detection method, connects three-phase power (2) with the wire respectively with the three-phase input of three-phase permanent magnet synchronous motor (1), connects a current sensor (3) in series respectively on the wire of every looks, and three current sensor (3) all use signal line connection director (4), characterized by: the method is implemented in sequence according to the following steps:
① sampling, wherein three current sensors (3) respectively sample phase A current Ia, phase B current Ib and phase C current Ic of a three-phase power supply (2), and the space vector modulation operating frequency controlled by the three-phase permanent magnet synchronous motor (1) is set as ffocThen each current is adoptedSample period TfocIs composed of
Figure FDA0002277909340000011
Each calculation period T of phase currentfCalculated as follows:
Figure FDA0002277909340000012
(1) in the formula:
n is the actual rotating speed of the motor after per unit,
Nbaseis a reference value of the rotating speed in the software,
p is the number of pole pairs of the motor;
respectively squaring the phase currents Ia, Ib and Ic obtained in each sampling period to obtain
Figure FDA0002277909340000013
And
Figure FDA0002277909340000014
respectively obtained in each half phase current calculation period
Figure FDA0002277909340000015
And
Figure FDA0002277909340000016
maximum value of
Figure FDA0002277909340000017
And
Figure FDA0002277909340000018
② filtering, namely, adopting a pair of recursive average filtering and median filtering algorithms
Figure FDA0002277909340000019
And
Figure FDA00022779093400000110
respectively carrying out the filtering treatment on the raw materials,
the recursive average filtering algorithm is also called as a sliding average filtering algorithm, namely, N continuous sampling values are regarded as a sequence, the length of the sequence is fixed to N, a new sampling value is sampled at each time and is placed at the tail end of the sequence, the sampling value at the head of the original sequence is removed, thus the length of the sequence is always kept fixed to N by a method of removing the sequence from the sampling values which enter the sequence first, and N data in the queue are subjected to arithmetic average calculation to obtain a sequence average value;
the median filtering algorithm can also be an anti-pulse interference filtering algorithm, continuously samples N sequences and obtains N sequence average values, removes the maximum and minimum two sequence average values, and obtains an arithmetic average value which is a filtering result value for the rest N-2 sequence average values;
specifically, the method comprises the following steps: setting:
the sequence obtained in the 1 st sampling period is L (1), the sampling values in the initial state of L (1) are { L (1), L (2), … …, L (N) }, and the arithmetic average of the N sampling values L (1) -L (N) is carried out to obtain
Figure FDA00022779093400000111
Continuing sampling to obtain a new sampling value L (N +1), adding L (N +1) into the L (1) sequence and locating at the tail end, removing the L (1) sequence from the L (1) sequence to obtain a new sequence L (2) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (2) -L (N +1) to obtain
Figure FDA0002277909340000021
……，
Continuing sampling to obtain a new sampling value L (N + i), adding L (N + i) into the sequence L (i) and locating at the tail end, removing the sequence L (i) from the sequence L (i) so as to obtain a new sequence L (i +1) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (i +1) -L (N + i) to obtain an arithmetic average value
Figure FDA0002277909340000022
……，
Continuing sampling to obtain a new sampling value L (2N-1), adding L (2N-1) into the L (2N-1) sequence and locating at the tail end, removing the L (2N-1) sequence from L (2N-1) so as to obtain a new sequence L (2N) still containing N sampling values, and carrying out arithmetic average on the N sampling values L (N) to L (2N-1) to obtain
Figure FDA0002277909340000023
Figure FDA0002277909340000024
And
Figure FDA0002277909340000025
forming a sequence L (N) containing N average values, eliminating the maximum value and the minimum value in the sequence L (N), and calculating the arithmetic average of the rest N-2 average values
Figure FDA0002277909340000026
The result value is the filtering result value;
wherein: n is a positive integer not less than 5, i is a positive integer and i belongs to (1, N);
filtered
Figure FDA0002277909340000027
And
Figure FDA0002277909340000028
are respectively marked as
Figure FDA0002277909340000029
And
Figure FDA00022779093400000210
setting a phase current determination threshold IDWhen is coming into contact with
Figure FDA00022779093400000211
And
Figure FDA00022779093400000212
at least one of the three values is greater than IDWhen the phase is short, the phase failure judgment is carried out;
③ phase loss judgment, first judgment
Figure FDA00022779093400000213
And
Figure FDA00022779093400000214
the maximum and minimum of these three values are noted as
Figure FDA00022779093400000215
And
Figure FDA00022779093400000216
order to
Figure FDA00022779093400000217
Comparing I with a phase current decision threshold IDIf I is smaller than IDAnd if the motor is in the open phase, the controller (4) immediately stops the operation of the three-phase permanent magnet synchronous motor (1) after the motor is judged to be in the open phase.
2. The method for detecting the phase loss of an electric motor as claimed in claim 1, wherein in step ①, f isfocTaking 10 kHz;
at step ②, N is not less than 10.
CN201911129569.7A 2019-11-11 2019-11-18 Motor phase loss detection method Pending CN110890740A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112540295A (en) * 2020-11-06 2021-03-23 珠海格力电器股份有限公司 Motor phase loss detection method, device, controller, phase loss detection circuit and equipment
CN116381492A (en) * 2023-06-07 2023-07-04 上海灵动微电子股份有限公司 Detection device for phase failure of three-phase DC brushless motor in operation

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CN102005727A (en) * 2010-11-12 2011-04-06 煤炭科学研究总院重庆研究院 Single motor protection device for dragging double motor through single frequency conversion
CN102195268A (en) * 2011-04-14 2011-09-21 新乡市夏烽电器有限公司 Integrated protector of alternating-current motor
CN102721923A (en) * 2011-03-29 2012-10-10 上海永大电梯设备有限公司 Motor phase loss detection method
CN106353609A (en) * 2016-09-29 2017-01-25 珠海格力节能环保制冷技术研究中心有限公司 Method and system for detecting phase failure of motor

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CN101615538A (en) * 2008-06-27 2009-12-30 上海亿盟电气自动化技术有限公司 A kind of release filter method
CN102005727A (en) * 2010-11-12 2011-04-06 煤炭科学研究总院重庆研究院 Single motor protection device for dragging double motor through single frequency conversion
CN102721923A (en) * 2011-03-29 2012-10-10 上海永大电梯设备有限公司 Motor phase loss detection method
CN102195268A (en) * 2011-04-14 2011-09-21 新乡市夏烽电器有限公司 Integrated protector of alternating-current motor
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Publication number Priority date Publication date Assignee Title
CN112540295A (en) * 2020-11-06 2021-03-23 珠海格力电器股份有限公司 Motor phase loss detection method, device, controller, phase loss detection circuit and equipment
CN116381492A (en) * 2023-06-07 2023-07-04 上海灵动微电子股份有限公司 Detection device for phase failure of three-phase DC brushless motor in operation
CN116381492B (en) * 2023-06-07 2023-09-15 上海灵动微电子股份有限公司 Detection device for phase failure of three-phase DC brushless motor in operation

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