Isolation switch dynamic performance simulation mathematical system

Abstract

The invention discloses a disconnecting switch dynamic performance simulation mathematical system, which comprises a motor model module and an equivalent rotational inertia and equivalent load analysis module, and is characterized in that for the motor model module, a driving motor model including rotor data and stator data is imported, and the motor model is simulated by adding a simulator; for an equivalent rotational inertia and equivalent load analysis module, rotational inertia and equivalent load need to be calculated in simulation. According to the isolation switch dynamic performance simulation mathematical system disclosed by the invention, a driving motor is simulated through Ansoft, and changes of a current curve, an acceleration curve and a motor torque curve under different faults are obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of high-voltage switches, and in particular relates to a dynamic performance simulation mathematical system for isolating switches. Background Art

[0002] In the existing technology, the dynamic performance analysis of the disconnector in GIS mainly relies on experimental methods, which are expensive and difficult to obtain the physical quantities inside the GIS. Therefore, it is of great significance to develop a simulation system that can accurately simulate the dynamic performance of the disconnector in GIS. Summary of the invention

[0003] The main purpose of the present invention is to provide a mathematical system for simulating the dynamic performance of the disconnector. By building a dynamic simulation model of the disconnector in GIS, the actual opening and closing of the switch is simulated by the model, and the rotation angular displacement curve of the outer arm during the opening and closing process is obtained; the drive motor is simulated by Ansoft, and the changes in the current curve, acceleration curve and motor torque curve under different faults are obtained.

[0004] To achieve the above objectives, the present invention provides a mathematical system for simulating the dynamic performance of an isolating switch, comprising a motor model module and an equivalent moment of inertia and equivalent load analysis module, wherein:

[0005] For the motor model module, import the drive motor model (in Ansoft software), including rotor data and stator data, and simulate the motor model by adding a simulator;

[0006] For the equivalent moment of inertia and equivalent load analysis module, the moment of inertia and equivalent load need to be calculated in the (Ansoft) simulation. Therefore, a simulation model is built for the (Ansoft) simulation. The actual opening and closing of the disconnector is simulated through the simulation model, and the changes in the current curve, acceleration curve and motor torque curve under different faults are obtained.

[0007] As a further preferred technical solution of the above technical solution, for the equivalent moment of inertia and equivalent load analysis module:

[0008] In the simulation, it is necessary to calculate the moment of inertia and equivalent load, and establish the motion relationship of each component of the disconnector in the GIS during the motion process, with the open state as the initial state and the closed state as the end state, as shown below:

[0009]

[0010] O is the main axis of the operating mechanism, OB is the crank arm in the tank, BC is the transmission connecting rod in the tank, CD is the insulating pull rod, Lx is the contact opening distance, Lm is the overtravel, θ αis the motor rotation angle, X is the horizontal movement distance of the insulating pull rod;

[0011] Calculate the equivalent moment of inertia:

[0012] In the calculation process of equivalent moment of inertia, the mass and moment of inertia of all transmission mechanisms are converted to the spindle side according to the law of conservation of energy. According to the law of conservation of energy, the following relationship exists among the mechanical components in the motion system:

[0013]

[0014] In the formula, J eq is the equivalent moment of inertia of the mechanical load side, ω1 is the angular velocity of the crank arm rotating around the main axis O in the tank, J cra is the equivalent moment of inertia of the crank arm in the tank around the main axis O, m lin is the mass of the transmission connecting rod, m mov is the mass of the moving contact, m ins is the mass of the insulating rod, v a is the velocity vector at the connection between the crank arm and the transmission connecting rod in the tank, V c is the velocity vector of the insulating rod, b c is the length of the transmission rod, and the transmission connecting rod is decomposed into rotational motion and linear motion, where V b1 is the linear velocity component of the transmission connecting rod, V b2 is the linear motion velocity component of the transmission connecting rod;

[0015] Assume that the contact pressure component in the opening distance stage during the closing process is f b1 , the contact pressure component in the overtravel stage is f b2 , the length of the inner arm of the tank is l a , the length of the transmission connecting rod is l b , the vertical distance between the main axis O and the insulating pull rod is l c , the angle between the crank arm in the tank and the initial angle at any time is θ α ;

[0016] During the opening phase of the operation, the equivalent load reaction force F at the spindle O point is b1 for:

[0017]

[0018] During the overtravel phase of the operation, the b1 and f b2 The action of the resultant force, the equivalent reaction force F at the main axis point O b2 for:

[0019]

[0020] When the disconnector is opening and closing, the angle between the transmission arm and the insulating rod changes very little. Therefore, when calculating the load torque, the angle θ α The load torque has a greater impact. When the disconnector is in the open distance stage, the equivalent load torque will change with the rotation angle θ α When the isolating switch is in the overtravel stage, the lever arm decreases, but due to the continuous increase in the contact pressure of the moving and static contacts in the overtravel stage, the increase in contact pressure is greater than the decrease in the lever arm. Therefore, the load torque still keeps increasing.

[0021] As a further preferred technical solution of the above technical solution, for the motor model module, a drive motor model is imported into the Ansoft software.

[0022] As a further preferred technical solution of the above technical solution, under the same control method, the degree of load fault is differentiated according to the difference in current and acceleration.

[0023] As a further preferred technical solution of the above technical solution, when all indicators of the angular displacement curve meet the standards, if the current curves are after the upper and lower envelopes, it is considered that the disconnector is fault-free; if the current curves exceed the upper and lower envelopes, it is considered that the disconnector has a mechanical fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the driving motor model diagram.

[0025] Figure 2 It is a simulation model diagram for Ansoft simulation.

[0026] Figure 3 It is the equivalent velocity component diagram of the main nodes of the transmission mechanism.

[0027] Figure 4 It is a curve chart of simulation results of abnormal structural jamming.

[0028] Figure 5 It is the curve diagram of transmission chain failure simulation results. DETAILED DESCRIPTION

[0029] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0030] In the preferred embodiment of the present invention, those skilled in the art should note that the isolating switch in GIS and the like involved in the present invention can be regarded as prior art.

[0031] Preferred embodiments.

[0032] The opening and closing process of the isolating switch in GIS is driven by the drive motor. During the opening and closing process, if there is a jam or increased friction, the current of the drive motor will increase instantly. When passing through this point, the current of the drive motor tends to be stable. Therefore, it is possible to determine whether the isolating switch has a mechanical fault by measuring the change in the current of the drive motor.

[0033] The present invention discloses a mathematical system for simulating dynamic performance of an isolating switch, comprising a motor model module and an equivalent moment of inertia and equivalent load analysis module, wherein:

[0034] For the motor model module, import the drive motor model (in Ansoft software), including rotor data and stator data, and simulate the motor model by adding a simulator;

[0035] For the equivalent moment of inertia and equivalent load analysis modules, the moment of inertia and equivalent load calculations need to be calculated in the (Ansoft) simulation, so a simulation model is built for the (Ansoft) simulation, such as Figure 2 As shown, the actual opening and closing of the disconnector is simulated by the simulation model, and the changes of the current curve, acceleration curve and motor torque curve under different faults are obtained.

[0036] Specifically, for the equivalent moment of inertia and equivalent load analysis modules:

[0037] In the simulation, it is necessary to calculate the moment of inertia and equivalent load, and establish the motion relationship of each component of the disconnector in the GIS during the motion process, with the open state as the initial state and the closed state as the end state, as shown below:

[0038]

[0039] O is the main axis of the operating mechanism, OB is the crank arm in the tank, BC is the transmission connecting rod in the tank, CD is the insulating pull rod, Lx is the contact opening distance, Lm is the overtravel, θ α is the motor rotation angle, X is the horizontal movement distance of the insulating pull rod;

[0040] Calculate the equivalent moment of inertia:

[0041] In the calculation process of equivalent moment of inertia, according to the law of conservation of energy, the mass and moment of inertia of all transmission mechanisms are returned to the main shaft side (during operation, the equivalent velocity components of the main nodes of the transmission mechanism are as follows Figure 3 As shown in Figure 2, according to the law of conservation of energy, the following relationships exist among the mechanical components in the motion system:

[0042]

[0043] In the formula, J eq is the equivalent moment of inertia of the mechanical load side, ω1 is the angular velocity of the crank arm rotating around the main axis O in the tank, J cra is the equivalent moment of inertia of the crank arm in the tank around the main axis O, m lin is the mass of the transmission connecting rod, m mov is the mass of the moving contact, m ins is the mass of the insulating rod, v a is the velocity vector at the connection between the crank arm and the transmission connecting rod in the tank, v c is the velocity vector of the insulating rod, b c is the length of the transmission rod, and the transmission connecting rod is decomposed into rotational motion and linear motion, where v b1 is the linear velocity component of the transmission connecting rod, v b2 is the linear motion velocity component of the transmission connecting rod;

[0044] Assume that the contact pressure component in the opening distance stage during the closing process is f b1 , the contact pressure component in the overtravel stage is f b2 , the length of the inner arm of the tank is l a , the length of the transmission connecting rod is l b , the vertical distance between the main axis O and the insulating pull rod is l c , the angle between the crank arm in the tank and the initial angle at any time is θ α ;

[0045] During the opening phase of the operation, the equivalent load reaction force F at the spindle O point is b1 for:

[0046]

[0047] During the overtravel phase of the operation, the b1 and f b2 The action of the resultant force, the equivalent reaction force F at the main axis point O b2 for:

[0048]

[0049] When the disconnector is opening and closing, the angle between the transmission arm and the insulating rod changes very little. Therefore, when calculating the load torque, the angle θ α The load torque has a greater impact. When the disconnector is in the open distance stage, the equivalent load torque will change with the rotation angle θ α When the isolating switch is in the overtravel stage, the lever arm decreases, but due to the continuous increase in the contact pressure of the moving and static contacts during the overtravel stage, the increase in contact pressure is greater than the decrease in the lever arm. Therefore, the load torque still keeps increasing.

[0050] More specifically, for the motor model module, the drive motor model is imported into the Ansoft software.

[0051] Furthermore, under the same control method, the load fault degree is differentiated according to the difference of current and acceleration.

[0052] Furthermore, when all indicators of the angular displacement curve meet the standards, if the current curves are after the upper and lower envelopes, it is considered that the disconnector has no fault; if the current curves exceed the upper and lower envelopes, it is considered that the disconnector has a mechanical fault.

[0053] Analyze the simulation results:

[0054] According to the fault conditions that have occurred on site, the external mechanical transmission structure is simulated for the loose pins in the transmission mechanism resulting in no-load mechanism, jamming due to structural abnormalities, and normal load. The results are as follows Figure 4 As shown below. Under normal circumstances, the current peak is 260.2A, the torque peak is 742N·m, the current peak is 185.9A, the torque peak is 575N·m, the stall current is 292A, the stall torque is 752N·m, and the three-phase current peak only appears before the first phase change. Under no-load conditions, the torque is 77.4% of the normal value, and the current is 71.5% of the normal value. Under normal circumstances, the torque and current show similar trends under no-load conditions, but there are many factors affecting torque fluctuations. In comparison, it is more stable to use current to judge the movement. The occurrence of jamming defects has obvious characteristics, the number of commutation is missing (the motor model used in this simulation should be commutated three times to complete the closing normally), the current and torque do not fluctuate at the commutation moment, and the motor angular acceleration mutates at the jamming position. When the no-load defect occurs, due to the idling of the motor, the starting torque and current are less than the normal working values, the motor acceleration changes violently and the amplitude is 5 times the normal value, the current commutation moment is significantly earlier than normal, and the motor collides violently at the limiter.

[0055] For the failure of the transmission chain that causes the mechanism phase to be disconnected in place but the non-mechanism phase is not separated, the motor torque, current, and acceleration under no-load, one-phase, two-phase, and three-phase loads are simulated and analyzed. Figure 5 As shown in the figure, the peak torque under one-phase load is 681N·m, the peak current is 230.1A, the peak torque under two-phase load is 715.2N·m, the peak current is 246.5A, the torque under one-phase load is 91.8% of the normal value, the current is 88.5% of the normal value; the torque under two-phase load is 96.4% of the normal value, the current is 94.7% of the normal value. The motor acceleration amplitude is 1908.8rad / s under no-load 2 , 1158.8rad / s under one phase load 2, 584.5rad / s under two-phase load 2 , 381.4rad / s under normal circumstances 2 , the acceleration values ​​under fault conditions are 5, 3, and 1.5 times the normal values, respectively. Compared with current and torque, in this type of fault, the acceleration reflects this type of fault more obviously, and the earlier the fault occurs, the more obvious the acceleration difference is.

[0056] The simulation results are summarized in Table 1. Through analysis, it can be known that if the current commutation is still not detected after exceeding the normal commutation time range and the current is basically stable, it means that a jamming fault has occurred; if the first commutation time is significantly different from the normal situation, it means that the load has changed significantly. If the time is advanced, the transmission components may be loosened, resulting in a decrease in load. If the time is delayed, the components may be stuck, causing increased friction and an increase in load. Under the same control method, the degree of load fault can be roughly distinguished according to the difference in current and acceleration. If the current is less than 70% of the normal value and the acceleration is several times the normal value, it can be considered that a serious fault has occurred; if the current is lower than the normal value and the acceleration has a large jitter, it can be considered that a fault has occurred.

[0057] Table 1

[0058]

[0059] After judging the angular displacement curve, what needs to be done is to judge the current signal. When all indicators of the angular displacement curve meet the standards (stroke, overtravel, curve similarity), if the current curves are all after the upper and lower envelopes, it is considered that the disconnector in the GIS is fault-free; if the current curve exceeds the upper and lower envelopes, it is considered that there is a mechanical failure in the disconnector in the GIS. The cause of this phenomenon may be the falling off of the internal crank arm pin, and the drive motor only drives the crank arm to rotate. At this time, no large torque is required, so the current will also decrease. However, since the angular displacement measures the rotational angular displacement of the external crank arm, the angular displacement curve is a normal curve. It is just that the phase-to-phase connecting rod is not connected to the external connecting rod, and the closing is not completed.

[0060] It is worth mentioning that the technical features such as the isolating switch in the GIS involved in the patent application of this invention should be regarded as the prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional methods in the field, and should not be regarded as the inventive point of the patent of this invention. The patent of this invention will not be further elaborated.

[0061] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A mathematical system for simulating dynamic performance of disconnectors, characterized in that: It includes motor model module and equivalent moment of inertia and equivalent load analysis module, among which: For the motor model module, import the drive motor model, including rotor data and stator data, and simulate the motor model by adding a simulator; For the equivalent moment of inertia and equivalent load analysis module, the moment of inertia and equivalent load need to be calculated in the simulation. Therefore, a simulation model is built for the simulation. The actual opening and closing of the disconnector is simulated through the simulation model, and the changes in the current curve, acceleration curve and motor torque curve under different faults are obtained.

2. A mathematical system for simulating dynamic performance of disconnectors according to claim 1, characterized in that: For equivalent moment of inertia and equivalent load analysis modules: In the simulation, it is necessary to calculate the moment of inertia and equivalent load, and establish the motion relationship of each component of the disconnector in the GIS during the motion process, with the open state as the initial state and the closed state as the end state, as shown below: O is the main axis of the operating mechanism, OB is the crank arm in the tank, BC is the transmission connecting rod in the tank, CD is the insulating pull rod, Lx is the contact opening distance, Lm is the overtravel, θ α is the motor rotation angle, X is the horizontal movement distance of the insulating pull rod; Calculate the equivalent moment of inertia: In the calculation process of equivalent moment of inertia, the mass and moment of inertia of all transmission mechanisms are converted to the spindle side according to the law of conservation of energy. According to the law of conservation of energy, the following relationship exists among the mechanical components in the motion system: In the formula, J eq is the equivalent moment of inertia of the mechanical load side, ω1 is the angular velocity of the crank arm rotating around the main axis O in the tank, J cra is the equivalent moment of inertia of the crank arm in the tank around the main axis O, m lin is the mass of the transmission connecting rod, m mov is the mass of the moving contact, m ins is the mass of the insulating rod, v a is the velocity vector at the connection between the crank arm and the transmission connecting rod in the tank, v c is the velocity vector of the insulating rod, b c is the length of the transmission rod, and the transmission connecting rod is decomposed into rotational motion and linear motion, where v b1 is the linear velocity component of the transmission connecting rod, v b2 is the linear motion velocity component of the transmission connecting rod; Assume that the contact pressure component in the opening distance stage during the closing process is f b1 , the contact pressure component in the overtravel stage is f b2 , the length of the inner arm of the tank is l a , the length of the transmission connecting rod is l b , the vertical distance between the main axis O and the insulating pull rod is l c , the angle between the crank arm in the tank and the initial angle at any time is θ α ; During the opening phase of the operation, the equivalent load reaction force F at the spindle O point is b1 for: During the overtravel phase of the operation, the b1 and f b2 The action of the resultant force, the equivalent reaction force F at the main axis point O b2 for: When the disconnector is opening and closing, the angle between the transmission arm and the insulating rod changes very little. Therefore, when calculating the load torque, the angle θ α The load torque has a greater impact. When the disconnector is in the open distance stage, the equivalent load torque will change with the rotation angle θ α When the isolating switch is in the overtravel stage, the lever arm decreases, but due to the continuous increase in the contact pressure of the moving and static contacts in the overtravel stage, the increase in contact pressure is greater than the decrease in the lever arm. Therefore, the load torque still keeps increasing.

3. A mathematical system for simulating dynamic performance of disconnectors according to claim 2, characterized in that: For the motor model module, import the drive motor model in Ansoft software.

4. A mathematical system for simulating dynamic performance of disconnectors according to claim 3, characterized in that: Under the same control method, the load fault degree is differentiated according to the difference in current and acceleration.

5. A mathematical system for simulating dynamic performance of disconnectors according to claim 4, characterized in that: When all indicators of the angular displacement curve meet the standards, if the current curves are after the upper and lower envelopes, it is considered that the disconnector has no fault; if the current curves exceed the upper and lower envelopes, it is considered that the disconnector has a mechanical fault.

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