阅读说明：本技术 一种基于定子电流复数分量的感应电机匝间短路故障诊断方法 (Induction motor turn-to-turn short circuit fault diagnosis method based on stator current complex component ) 是由 谢颖 陈鹏 胡圣明 李道璐 魏静微 于 2019-12-03 设计创作，主要内容包括：一种基于定子电流复数分量的感应电机匝间短路故障诊断方法,涉及电机故障诊断技术领域。本发明是为了解决现有的匝间短路故障诊断技术,由于信号处理复杂,需要大量探测器传感器设备的问题。本发明所述的一种基于定子电流复数分量的感应电机匝间短路故障诊断方法,可用于诊断感应电机匝间短路故障；本发明所需设备少,结果处理简便；不受电机运行工况限制,在空载和负载条件均可有效诊断故障,还能够在故障情况下识别故障发生相。(A method for diagnosing turn-to-turn short circuit fault of an induction motor based on a stator current complex component relates to the technical field of motor fault diagnosis. The invention aims to solve the problem that a large amount of detector sensor equipment is needed due to complex signal processing in the existing turn-to-turn short circuit fault diagnosis technology. The method for diagnosing the turn-to-turn short circuit fault of the induction motor based on the complex component of the stator current can be used for diagnosing the turn-to-turn short circuit fault of the induction motor; the invention needs less equipment and has simple and convenient result processing; the method is not limited by the operation condition of the motor, can effectively diagnose the fault under the conditions of no load and load, and can identify the fault occurrence phase under the fault condition.)

1. A method for diagnosing turn-to-turn short circuit fault of an induction motor based on a stator current complex component is characterized by comprising the following steps:

the method comprises the following steps: collecting three-phase stator current i of induction motor to be diagnosed _a、i _b、i _c，

Step two: substituting the three-phase stator current into a matrix of a complex component method to respectively calculate a complex component i of the three-phase stator current ₁、i ₂、i ₀，

Step three: combining the complex component i ₁Real part of (i) _1xAnd imaginary part i _1yThe picture is drawn on a plurality of planes,

step four: determining the shape of the trace drawn on the plurality of planes,

when the track is circular, step five is executed,

when the track is elliptical, the induction motor is judged to have turn-to-turn short circuit fault,

step five: determining the complex component i ₁Whether the real and imaginary parts of (c) satisfy the following equation:

wherein, delta is a designated threshold value,

if so, judging that the induction motor has turn-to-turn short circuit fault,

otherwise, judging that the induction motor has no turn-to-turn short circuit fault.

2. The method of claim 1, further comprising the steps of, after determining that the induction machine has a turn-to-turn short fault:

when the long axis of the track is positioned at the second and the fourth boundaries of the complex plane, the failure of the phase A of the induction motor is judged,

when the long axis of the track is parallel to the longitudinal axes of the plurality of planes, the failure of the B phase of the induction motor is judged,

and when the long axis of the track is positioned in the first and third boundaries of the complex plane, judging that the phase C of the induction motor has a fault.

3. The method for diagnosing turn-to-turn short circuit fault of induction motor based on stator current complex component according to claim 1 or 2, characterized in that in the second step, the matrix form of the complex component method is as follows:

wherein the content of the first and second substances,

the complex component i of the three-phase stator current is calculated according to ₁、i ₂、i ₀：

4. The method of claim 3, wherein the complex component i of the three-phase stator current is the complex component of the stator current ₁And i ₂Are mutually conjugated complex numbers i ₁The expression of (a) is:

i ₁＝i _1x+ji _1y。

5. the method for diagnosing turn-to-turn short circuit fault of the induction motor based on the stator current complex component as claimed in claim 1 or 2, wherein δ is 1.

Technical Field

The invention belongs to the technical field of motor fault diagnosis, and particularly relates to diagnosis of turn-to-turn short circuit faults of an induction motor.

Background

Induction motors are widely used in various industrial applications due to their advantages of simple structure, robustness, low cost, etc. According to the related statistical data, the proportion of the electric quantity consumed by the induction motor in the total load of the power grid reaches about 40%.

As main power equipment in production and life, whether the induction motor operates healthily and stably or whether the fault can be diagnosed in time at the initial stage of the fault of the motor has important significance on the safety of industrial production equipment and operators.

The induction motor has various faults due to the influence of factors such as complex use working conditions, severe use environment conditions and the like. According to statistics, the stator fault accounts for 30% -40% of the AC motor fault types, wherein the turn-to-turn short circuit fault is the most typical fault type of the stator fault. If the inter-turn short circuit fault cannot be detected and diagnosed in time, the temperature rise caused by the fault current can rapidly destroy the insulation of the motor, so that the more serious inter-turn short circuit fault is caused, the motor can be burnt out, the operation of the whole industrial system is influenced, and huge economic loss and personnel potential safety hazards are caused.

The existing turn-to-turn short circuit fault diagnosis technology has the defects of complex signal processing, requirement of a large number of detector and sensor devices and high cost of a diagnosis system. Therefore, the diagnostic method which is simple in detection method, simple and convenient in signal processing process and good in diagnostic effect has important practical significance.

Disclosure of Invention

The invention provides a turn-to-turn short circuit fault diagnosis method of an induction motor based on a stator current complex component, aiming at solving the problem that a large amount of detector sensor equipment is needed due to complex signal processing in the existing turn-to-turn short circuit fault diagnosis technology.

A method for diagnosing turn-to-turn short circuit fault of an induction motor based on a stator current complex component comprises the following steps:

the method comprises the following steps: collecting three-phase stator current i of induction motor to be diagnosed _a、i _b、i _c，

Step two: substitution of three-phase stator currents into complex component methodCalculating the complex components i of three-phase stator currents in matrix ₁、i ₂、i ₀，

Step three: combining the complex component i ₁Real part of (i) _1xAnd imaginary part i _1yThe picture is drawn on a plurality of planes,

step four: determining the shape of the trace drawn on the plurality of planes,

when the track is circular, step five is executed,

when the track is elliptical, the induction motor is judged to have turn-to-turn short circuit fault,

step five: determining the complex component i ₁Whether the real and imaginary parts of (c) satisfy the following equation:

wherein, delta is a designated threshold value,

if so, judging that the induction motor has turn-to-turn short circuit fault,

otherwise, judging that the induction motor has no turn-to-turn short circuit fault.

Further, after the induction motor is judged to have the turn-to-turn short circuit fault, the method further comprises the following steps:

when the long axis of the track is positioned at the second and the fourth boundaries of the complex plane, the failure of the phase A of the induction motor is judged,

when the long axis of the track is parallel to the longitudinal axes of the plurality of planes, the failure of the B phase of the induction motor is judged,

and when the long axis of the track is positioned in the first and third boundaries of the complex plane, judging that the phase C of the induction motor has a fault.

Further, the matrix form of the complex component method in the second step is as follows:

wherein the content of the first and second substances,

the complex component i of the three-phase stator current is calculated according to ₁、i ₂、i ₀：

Further, the complex component i of the three-phase stator current ₁And i ₂Are mutually conjugated complex numbers i ₁The expression of (a) is:

i ₁＝i _1x+ji _1y。

the invention has the beneficial effects that:

the method for diagnosing the turn-to-turn short circuit fault of the induction motor based on the complex component of the stator current can be used for diagnosing the turn-to-turn short circuit fault of the induction motor; the invention needs less equipment and has simple and convenient result processing; the method is not limited by the operation condition of the motor, can effectively diagnose the fault under the conditions of no load and load, and can identify the fault occurrence phase under the fault condition.

Drawings

FIG. 1 is an equivalent circuit diagram of a phase A turn-to-turn short circuit fault of a motor stator;

FIG. 2 is a flow chart of a method for diagnosing turn-to-turn short circuit faults of an induction motor based on a complex component of stator current;

FIG. 3 is a complex plot of the trajectories for three cases under no-load conditions, wherein (a) no-load healthy, (b) no-load 25 turn fault, (c) no-load 45 turn fault;

FIG. 4 is a diagram showing the ratio of the long axis to the short axis of the trajectory for three conditions under no-load conditions;

FIG. 5 is a complex plan trace plot for three cases under nominal load conditions, wherein (a) load healthy, (b) load 25 turn fault, (c) load 45 turn fault;

FIG. 6 is a schematic diagram of the ratio of the major and minor axes of the trajectory for three conditions under nominal load conditions;

fig. 7 is a complex plane trace diagram of turn-to-turn short circuit faults occurring at different positions of three phases of a stator under an unloaded condition, wherein (a) an unloaded 45-turn fault-a phase, (B) an unloaded 45-turn fault-B phase, and (C) an unloaded 45-turn fault-C phase.

Detailed Description

Fig. 1 is an equivalent circuit diagram of a phase a turn-to-turn short circuit of an induction motor stator, and since the turn-to-turn insulation level of the motor decreases, there is a contact resistance between short-circuited coils, in this embodiment, the contact resistance is 4 Ω under no load and 3 Ω under load, and the specific parameters are as shown in table 1:

TABLE 1 Induction machine stator parameter table

The simulation was performed according to the conditions in table 1 and then processed using the method in the following detailed description.