CN-122017560-A - Motor winding turn-to-turn short circuit and interphase short circuit fault diagnosis device and method

CN122017560ACN 122017560 ACN122017560 ACN 122017560ACN-122017560-A

Abstract

The invention discloses a motor winding turn-to-turn short circuit and interphase short circuit fault diagnosis device and method. The device comprises a phase detection unit, an inter-phase short circuit detection unit, a winding short circuit audible and visual alarm unit, an inter-phase short circuit positioning indication unit, a microcontroller and an execution driving unit. The method comprises the steps of S1, signal acquisition, S2, winding short circuit detection and indication, S3, interphase short circuit judgment and indication, S4, fault type distinguishing, S5, protection action, and S6, fault recording. The invention has simple structure, low cost, high response speed and high sensitivity, can clearly distinguish and indicate the types and the phases of turn-to-turn short circuit and interphase short circuit faults, and realizes the rapid detection and the protection of the early short circuit faults of the motor winding.

Inventors

LI CHUANG
DING ZHIJUN
WANG JINXIAN
SUN WENBIN
LI HAIMAO

Assignees

南通贝卡迪电力科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (8)

1. The motor winding turn-to-turn short circuit and interphase short circuit fault diagnosis device is characterized by comprising a phase detection unit, an interphase short circuit detection unit, a winding short circuit audible and visual alarm unit, an interphase short circuit positioning indication unit, a microcontroller and an execution driving unit, The phase detection unit comprises a first reed switch (1), a second reed switch (2) and a third reed switch (3), wherein single windings are respectively arranged on the first reed switch (1), the second reed switch (2) and the third reed switch (3), the single windings are respectively a first winding (11) arranged on the first reed switch (1), a second winding (21) arranged on the second reed switch (2) and a third winding (31) arranged on the third reed switch (3), the first winding (11) is connected in series with a motor A phase incoming line, the second winding (21) is connected in series with a motor B phase incoming line, and the third winding (31) is connected in series with a motor C phase incoming line; The inter-phase short circuit detection unit comprises a first differential reed switch (4), a second differential reed switch (5) and a third differential reed switch (6), wherein double windings are respectively arranged on the first differential reed switch (4), the second differential reed switch (5) and the third differential reed switch (6), namely a fourth winding (41) and a fifth winding (42) which are respectively arranged on the first differential reed switch (4), a sixth winding (51) and a seventh winding (52) which are respectively arranged on the second differential reed switch (5), and an eighth winding (61) and a ninth winding (62) which are respectively arranged on the third differential reed switch (6), and the fourth winding (41), the sixth winding (51), the eighth winding (61), the fifth winding (42), the seventh winding (52) and the ninth winding (62) are respectively wound reversely, wherein the fourth winding (41), the sixth winding (51) and the eighth winding (61) are respectively connected into a phase, a phase B, a phase C and a phase, a phase C and a phase C and a phase are respectively connected into a series circuit, and a neutral circuit; The input end of the microcontroller (7) is electrically connected with the first reed switch (1), the second reed switch (2), the third reed switch (3), the first differential reed switch (4), the second differential reed switch (5) and the third differential reed switch (6) respectively; The execution driving unit comprises a driving mechanism (8), and the input end of the driving mechanism (8) is electrically connected with the output end of the microcontroller (7); The winding short-circuit audible and visual alarm unit comprises a winding short-circuit audible and visual alarm (9), and the winding short-circuit audible and visual alarm (9) is connected to the output end of the microcontroller (7) through a driving mechanism (8); The interphase short circuit positioning indication unit comprises a winding interphase short circuit indication lamp set (10), the winding interphase short circuit indication lamp set (10) comprises three indication lamps corresponding to an A phase, a B phase and a C phase of the motor respectively, and the three indication lamps are connected to a corresponding first differential reed switch (4), a corresponding second differential reed switch (5) and a corresponding third differential reed switch (6) respectively through three independent indication lamp driving units or are directly connected to corresponding output ends of the microcontroller (7).
2. The motor winding turn-to-turn short circuit and inter-phase short circuit fault diagnosis device according to claim 1, characterized in that the parameters and specifications of the first reed switch (1), the second reed switch (2) and the third reed switch (3) are the same.
3. The device for diagnosing motor winding turn-to-turn short circuit and inter-phase short circuit according to claim 1, wherein the magnetic induction intensities generated by the two windings of the differential reed switch of the same phase are equal in magnitude and opposite in direction at the sensitive element, the resultant magnetic induction intensity is smaller than the action threshold value, and the resultant magnetic induction intensity of the differential reed switch of the corresponding phase exceeds the threshold value to reliably act the contact only when the inter-phase short circuit occurs in the motor, so that the current relation between the power side and the neutral point side of the fault phase is fundamentally changed.
4. The motor winding turn-to-turn short circuit and inter-phase short circuit fault diagnosis device according to claim 1, characterized in that the microcontroller (7) is internally integrated with: A plurality of timers for measuring time intervals between the respective reed switch trigger signals; The logic comparison unit is used for calculating the phase angle according to the time interval and comparing the phase angle with a preset threshold value; And the memory is used for storing the threshold value parameter, the delay logic and the fault record.
5. The device for diagnosing motor winding turn-to-turn short circuit and inter-phase short circuit fault according to claim 1, wherein a starting locking logic unit is arranged in the microcontroller (7), and at the moment of motor starting, a short delay is started by the microcontroller (7), and the turn-to-turn short circuit judging function is temporarily shielded within the short delay.
6. The apparatus for diagnosing a turn-to-turn short circuit and an inter-phase short circuit fault of a motor winding according to claim 1, wherein said indicator lamp driving unit comprises: A PNP triode with its emitter connected to +5V power supply; The anode of the light-emitting diode is connected to the collector electrode of the corresponding PNP triode through a current-limiting resistor, and the cathode of the light-emitting diode is grounded; the base resistor is connected between the contact of the corresponding reed switch and the base of the corresponding PNP triode; A current limiting resistor; A pull-up resistor; one end of each differential reed switch contact is grounded, and the other end is connected to a +5V power supply through a corresponding pull-up resistor and is simultaneously connected to a corresponding input pin and a corresponding base resistor of the microcontroller (7).
7. A motor winding turn-to-turn short circuit and interphase short circuit fault diagnosis method based on any one of claims 1-6, characterized by comprising the following steps: s1, signal acquisition: acquiring zero crossing or amplitude triggering signals of three-phase current of the motor in real time through the first reed switch (1), the second reed switch (2) and the third reed switch (3); s2, winding short circuit detection and indication: the microcontroller (7) calculates the phase angle between the currents of each phase of the motor according to the time difference of the trigger signals of the reed switches detected by each phase, and if the amplitude of any phase angle deviating from the rated symmetry value by 120 degrees exceeds a first preset threshold value and the duration meets the condition, the occurrence of winding short circuit is judged, and at the moment, the winding short circuit audible and visual alarm unit starts to alarm; s3, judging and indicating interphase short circuit: the microcontroller (7) monitors the contact states of the first differential reed switch (4), the second differential reed switch (5) and the third differential reed switch (6): if the first differential reed switch (4) and the second differential reed switch (5) are closed at the same time, judging that an A-B interphase short circuit occurs, and controlling the corresponding indicator lamps of the A phase and the B to be lighted; If the second differential reed switch (5) and the third differential reed switch (6) are closed at the same time, judging that B-C interphase short circuit occurs, and controlling the corresponding indicator lamps of the B phase and the C to be lighted; if the first differential reed switch (4) and the third differential reed switch (6) are closed at the same time, judging that an A-C interphase short circuit occurs, and controlling the corresponding indicator lamps of the A phase and the C to be lighted; s4, distinguishing fault types: If the winding short-circuit audible and visual alarm unit alarms, no indicator lamp in the winding interphase short-circuit indicator lamp group (10) is lighted, the fault is comprehensively judged to be an inter-turn short circuit, and if any indicator lamp in the winding interphase short-circuit indicator lamp group (10) is lighted while the winding short-circuit audible and visual alarm unit alarms, the fault is comprehensively judged to be an interphase short circuit of a corresponding type; S5, protection action: when the occurrence of winding short circuit is judged, the microcontroller (7) controls the execution driving unit to drive the contactor to open, and the motor power supply is cut off; S6, fault record: The microcontroller (7) stores the time, type, and related phase information of the occurrence of the fault in a memory.
8. The method for diagnosing motor winding turn-to-turn short and inter-phase short fault according to claim 7, wherein in step S1: At the moment of starting the motor, the microcontroller (7) starts a starting locking logic unit to start a short delay locking period, and the turn-to-turn short circuit judgment logic is suspended in the short delay locking period to prevent misoperation caused by starting current impact.

Description

Motor winding turn-to-turn short circuit and interphase short circuit fault diagnosis device and method Technical Field The invention relates to the technical field of motor fault diagnosis and protection, in particular to a device and a method for detecting turn-to-turn short circuit and interphase short circuit faults of a stator winding of a motor. Background The motor is used as a core power device, is widely applied to various fields of industrial manufacture, transportation, construction engineering, new energy power generation and the like, and the running reliability and the running safety of the motor are very important. The turn-to-turn short circuit and the inter-phase short circuit of the stator winding are common electric faults of the motor, if the electric faults are not detected and processed in time, the local overheating of the motor and the accelerated degradation of the insulation performance are easily caused, and even the safety accidents such as fire or explosion can be caused when the electric faults are serious. At present, a protection device commonly adopted by a motor mainly comprises a thermal relay, a fuse, an electromagnetic circuit breaker and the like. The traditional protection modes mainly aim at overload, locked rotor and serious interphase short-circuit faults, the action characteristics of the traditional protection modes are often based on current amplitude detection, and the sensitivity of the traditional protection modes to early and slight interphase short-circuit faults is seriously insufficient, so that a protection dead zone exists. In addition, such devices operate at a relatively slow rate, often requiring hundreds of milliseconds or even seconds to operate, and are difficult to meet the requirements of a quick-break fault. In order to improve the capability of detecting turn-to-turn short circuit faults, various methods are proposed in the prior art, such as monitoring negative sequence current, detecting a stator end part synthetic magnetic field, analyzing zero sequence voltage components and the like. However, the method is more applied to the protection of the high-voltage motor, and has obvious obstacles in popularization in the field of the high-voltage motor, namely, the first method is not provided with a special current and voltage transformer, the cost for installing the sensor is high, the transformation is complex, the second method based on negative sequence current is easily interfered by power grid asymmetry and two-phase short circuit outside the motor and is difficult to set, and the third method can only detect turn-to-turn short circuit and cannot give consideration to interphase short circuit and open-phase fault. Therefore, the universal motor protection device and method which have the advantages of simple structure, low cost and quick response and can detect turn-to-turn and inter-phase short circuit faults simultaneously are developed, and the universal motor protection device and method have important engineering practical values. Disclosure of Invention The invention provides a motor winding turn-to-turn short circuit and interphase short circuit fault diagnosis device and method based on reed switch and phase angle monitoring, which aims to overcome the defects of low sensitivity, low speed, single function and higher cost of the prior motor protection technology on early winding short circuit faults. The device does not need a traditional current transformer, directly uses the reed switch as a current sensing and logic triggering element, diagnoses turn-to-turn short circuit by monitoring phase angle abnormality between three-phase currents of the motor, and reliably identifies the inter-phase short circuit inside the motor by using an innovative differential reed switch structure, thereby realizing rapid, accurate and low-cost multiple fault protection. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The motor winding turn-to-turn short circuit and interphase short circuit fault diagnosis device comprises a phase detection unit, an interphase short circuit detection unit, a winding short circuit audible and visual alarm unit, an interphase short circuit positioning indication unit, a microcontroller and an execution driving unit, The phase detection unit comprises a first reed switch, a second reed switch and a third reed switch, wherein single windings are respectively arranged on the first reed switch, the second reed switch and the third reed switch, and are respectively a first winding arranged on the first reed switch, a second winding arranged on the second reed switch and a third winding arranged on the third reed switch, the first winding is connected in series with a phase A wire of a motor, the second winding is connected in series with a phase B wire of the motor, and the third winding is connected in series with a phase C wire of the motor; The interphase short circuit