Insulation resistance automatic detection system

Abstract

The invention discloses an insulation resistance automatic detection system, and relates to the technical field of insulation resistance automatic detection. The insulation resistance automatic detection system comprises a KA2 relay module, a KA3 relay module and a resistance insulation detector. The KA2 relay module and the KA3 relay module can be connected through an SA1 change-over switch. The resistance insulation detector of the insulation resistance automatic detection system transmits insulation resistance detection data to the PLC, converts the insulation resistance detection data into RS-485 signals through self voltage signals and then transmits the RS-485 signals to the DCS computer, and the DCS computer displays a resistance value on the display. An inspector can directly know the insulation resistance value of the motor in a standby state through the resistance value on the display, so that the insulation resistance value of the standby motor can be conveniently monitored in real time, and the situation that the motor is burnt out when the motor is used due to the fact that the insulation resistance is reduced and cannot be found in time when the motor is affected with damp is prevented; and meanwhile, the labor cost of workers is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of automatic insulation resistance detection, in particular to an automatic insulation resistance detection system. Background Art

[0002] The motor-to-ground resistance refers to the resistance between the motor winding and the ground. Under normal circumstances, the motor winding should be insulated from the ground, and the resistance value should be very high. If the motor-to-ground resistance value is too low, it will cause current to appear between the motor winding and the ground, which will cause motor failure and safety hazards. Therefore, the motor-to-ground resistance is one of the important indicators of motor insulation performance. The magnitude of the motor-to-ground resistance value is related to factors such as the insulation quality of the motor winding, the structure and material of the winding, and the temperature of the winding. Under normal circumstances, the motor-to-ground resistance value should be above several megohms. If the motor-to-ground resistance value is lower than a certain threshold, insulation testing and maintenance should be performed. In modern motor control systems, the monitoring and protection of the motor-to-ground resistance value has become an indispensable technology.

[0003] The insulation resistance of the motor to the ground is generally measured by shaking the meter to measure the resistance value. First, the stator coil of the high-voltage motor is measured with a 2500V megohmmeter, and its insulation resistance value is not less than 1MΩ per kilovolt; second, the stator coil of the low-voltage motor is measured with a 500V megohmmeter, and the resistance value is not less than 0.5MΩ; third, the stator coil of the DC motor is measured with a 1000V megohmmeter, and the resistance value is not less than 0.5MΩ; fourth, the measured value should be compared with the previous value at the same temperature. If it is lower than 70% of the previous measured value, the reason should be found out; fifth, the absorption ratio R60' / R15', the ratio is not less than 1.3. The resistance can also be measured with a multimeter or an electronic tester, which is more accurate than the value displayed by the shaking meter.

[0004] In daily work, some motors are in standby mode for a long time. Since the motor is in standby mode for a long time, the motor is likely to be affected by moisture, resulting in reduced insulation resistance. When the insulation resistance of the motor is reduced to below 0.5MΩ, once the motor is turned on, the motor will burn due to low insulation resistance. If the motor can be tested in real time in standby mode, the low insulation resistance of the motor can be discovered early, so that it can be properly handled, which can avoid the motor burning due to low insulation resistance and affect production, and at the same time protect the motor itself.

[0005] Therefore, we proposed an automatic insulation resistance detection system to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide an automatic insulation resistance detection system to solve the problem raised in the above background technology that some motors on the market are in standby state for a long time. Since the motor is in standby state for a long time, the motor is likely to be affected by moisture, resulting in reduced insulation resistance. When the insulation resistance of the motor is reduced to below 0.5MΩ, once the motor is turned on, the motor will burn out due to the low insulation resistance value.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an automatic insulation resistance detection system, which includes a KA2 relay module, a KA3 relay module and a resistance insulation tester. The KA2 relay module and the KA3 relay module can be connected to each other through the SA1 conversion switch respectively, and the KA3 relay module is connected to the resistance detection contactor KM2, the KA2 relay module is connected to the running contactor KM1, and the running contactor KM1 is connected to the motor, and the resistance detection contactor KM2 is connected to the resistance insulation tester.

[0008] Preferably, the SA1 switching switch can be connected to the KA2 relay module and the KA3 relay module respectively, and the SA1 switching switch can only be connected to one of the KA2 relay module and the KA3 relay module at a time, and the connection method is electrical connection.

[0009] With the above-mentioned design, when the SA1 transfer switch is connected to the KA2 relay module, the SA1 transfer switch is disconnected from the KA3 relay module. At this time, the KA2 relay module is turned on through the SA1 transfer switch. At this time, the KA3 relay module is in a disconnected state, that is, the resistance detection contactor KM2 is in a disconnected state, and the resistance detection contactor KM2 cannot trigger the resistance insulation detector to detect the insulation resistance of the motor. At the same time, the KA2 relay module turns on the running contactor KM1, so that the running contactor KM1 promotes the operation of the motor; when the SA1 transfer switch is connected to the KA3 relay module, the SA1 transfer switch and The KA2 relay module is disconnected, and the motor is in standby mode. The KA3 relay module is turned on through the SA1 switching switch. The KA3 relay module is connected to the resistance detection contactor KM2. The resistance detection contactor KM2 triggers the resistance insulation tester to detect the insulation resistance of the motor. The resistance insulation tester transmits the insulation resistance detection data to the PLC controller, and converts it into an RS-485 signal through its own voltage signal, and then transmits it to the DCS computer. The DCS computer displays the resistance value on the display. The inspection personnel can directly know the insulation resistance value of the motor in the standby mode through the resistance value on the display.

[0010] Preferably, the resistance insulation tester can detect the insulation resistance in the motor, and the AC power supply on the motor circuit can be converted through a rectifier module.

[0011] By adopting the above design scheme, the AC power supply on the motor circuit can be converted into DC power supply through the rectifier module, and then the DC power supply is used to power the resistance insulation tester, thereby improving the voltage stability of the resistance insulation tester when detecting the insulation resistance in the motor, and improving the detection efficiency of the resistance insulation tester.

[0012] Preferably, the rectifier module and the resistance insulation tester can be connected to each other, and the rectifier module and the resistance insulation tester are electrically connected, so that the rectifier module and the resistance insulation tester form a combined component.

[0013] By adopting the above design scheme, a regulated power supply is provided to the resistance insulation tester through a rectifier module, thereby realizing energy supply to the resistance insulation tester.

[0014] Preferably, the resistance insulation tester is connected to a PLC controller, and the resistance insulation tester can convert the detected motor insulation resistance value through its own voltage signal.

[0015] With the above design, the resistance insulation tester transmits the resistance detection data to the PLC controller, and converts it into RS-485 signal through its own voltage signal, which is convenient for the subsequent reading of the motor insulation resistance data.

[0016] Preferably, the resistance insulation tester is connected to a DCS computer, and the DCS computer is connected to a display, and the DCS computer and the display are electrically connected.

[0017] With the above design, the resistance insulation tester transmits the detected resistance data to the DCS computer, and then the insulation resistance data is transmitted to the display through the DCS computer, so that the staff can view it in real time.

[0018] Preferably, the running contactor KM1 and the resistance detection contactor KM2 can be electrically interlocked through their respective normally closed contacts, so that the running contactor KM1 and the resistance detection contactor KM2 cannot operate at the same time.

[0019] When the above-mentioned design scheme is adopted and the running contactor KM1 and the resistance detection contactor KM2 are interlocked, it can be ensured that when the motor is running, the running contactor KM1 is connected and the resistance detection contactor KM2 is disconnected. At this time, the insulation resistance of the motor cannot be detected. At the same time, when detecting the insulation resistance of the motor, the running contactor KM1 is disconnected and the resistance detection contactor KM2 is connected. At this time, the motor cannot be run, thereby ensuring the safety of the staff when detecting the insulation resistance.

[0020] Preferably, when the resistance insulation tester is powered on to detect the insulation resistance of the motor, the motor is in a standby state.

[0021] With the above design, for motors that are in standby mode for a long time, inspection personnel can observe the insulation condition of the standby motor at any time to prevent the insulation resistance of the motor from being reduced when it is damp and not being discovered in time, resulting in the motor burning out when it is used.

[0022] Preferably, the working process of the automatic insulation resistance detection system is as follows:

[0023] S1. Assemble the resistance insulation tester inside the motor control circuit, and take AC220V AC power supply on the motor circuit, pass the AC220V AC power supply through the rectifier module, and convert it into DC power supply after passing through the rectifier module. Then, the converted DC power supply is used to power the resistance insulation tester, so that the resistance insulation tester can stably detect the insulation resistance of the motor;

[0024] S2. When the motor is in the standby state, the KA3 relay module is turned on through the SA1 conversion switch. The KA3 relay module is connected to the resistance detection contactor KM2. The resistance detection contactor KM2 triggers the resistance insulation tester to detect the insulation resistance of the motor. The resistance insulation tester transmits the insulation resistance detection data to the PLC controller, and converts it into an RS-485 signal through its own voltage signal, and then transmits it to the DCS computer. The DCS computer displays the resistance value on the display. The inspection personnel can directly know the insulation resistance value of the motor in the standby state through the resistance value on the display; when the motor is in the enabled state, the KA2 relay module is turned on through the SA1 conversion switch. At this time, the KA3 relay module is in the disconnected state, that is, the resistance detection contactor KM2 is in the disconnected state, and the resistance detection contactor KM2 cannot trigger the resistance insulation tester to detect the insulation resistance of the motor. At the same time, the KA2 relay module turns on the running contactor KM1, so that the running contactor KM1 promotes the operation of the motor.

[0025] Compared with the prior art, the invention has the following beneficial effects: the automatic insulation resistance detection system:

[0026] 1. An operating contactor KM1 and a resistance detection contactor KM2 are provided. When the operating contactor KM1 and the resistance detection contactor KM2 are in an interlocking structure, it can be ensured that when the motor is running, the operating contactor KM1 is connected and the resistance detection contactor KM2 is disconnected. At this time, the insulation resistance of the motor cannot be detected. At the same time, when the insulation resistance of the motor is detected, the operating contactor KM1 is disconnected and the resistance detection contactor KM2 is connected. At this time, the motor cannot be operated, thereby ensuring the safety of the staff when detecting the insulation resistance;

[0027] 2. Provide a regulated power supply to the resistance insulation tester through the rectifier module to realize the energy supply to the resistance insulation tester, so that the resistance insulation tester can stably detect the insulation resistance of the motor;

[0028] 3. The resistance insulation tester transmits the insulation resistance test data to the PLC controller, and converts it into RS-485 signal through its own voltage signal, and then transmits it to the DCS computer. The DCS computer displays the resistance value on the display. The inspection personnel can directly know the insulation resistance value of the motor in the standby state through the resistance value on the display, which is convenient for real-time monitoring of the insulation resistance value of the standby motor, to prevent the insulation resistance of the motor from being reduced when it is damp and cannot be discovered in time, resulting in the motor burning when it is used, and at the same time reducing the labor cost;

[0029] 4. When running the motor, you only need to connect the SA1 switch to the KA2 relay module, and disconnect the SA1 switch from the KA3 relay module. At this time, the KA2 relay module is connected through the SA1 switch. At this time, the KA3 relay module is in the disconnected state, that is, the resistance detection contactor KM2 is in the disconnected state. The resistance detection contactor KM2 cannot trigger the resistance insulation tester to detect the insulation resistance of the motor. At the same time, the KA2 relay module connects the running contactor KM1, so that the running contactor KM1 promotes the operation of the motor, thereby ensuring that the motor can be put into operation at any time, which is convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall circuit structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the working process of the present invention;

[0032] Figure 3 The figure is a schematic diagram of the test data conversion process of the resistance insulation tester of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1-3The present invention provides a technical solution: an insulation resistance automatic detection system, the insulation resistance automatic detection system includes a KA2 relay module, a KA3 relay module and a resistance insulation detector, the KA2 relay module and the KA3 relay module can be connected through a SA1 conversion switch respectively, and the KA3 relay module is connected to a resistance detection contactor KM2, the KA2 relay module is connected to a running contactor KM1, and the running contactor KM1 is connected to a motor, and the resistance detection contactor KM2 is connected to the resistance insulation detector.

[0035] The resistance insulation tester can detect the insulation resistance in the motor, and the AC power supply on the motor circuit can be converted into DC power supply through the rectifier module. The DC power supply is then used to power the resistance insulation tester, thereby improving the voltage stability of the resistance insulation tester when detecting the insulation resistance in the motor and improving the detection efficiency of the resistance insulation tester.

[0036] The rectifier module and the resistance insulation tester can be interconnected, and the rectifier module and the resistance insulation tester are electrically connected, so that the rectifier module and the resistance insulation tester form a combined component. The rectifier module provides a regulated power supply to the resistance insulation tester to realize energy supply to the resistance insulation tester.

[0037] The resistance insulation tester is connected to the PLC controller, and the resistance insulation tester can convert the detected motor insulation resistance value through its own voltage signal. The resistance insulation tester transmits the resistance detection data to the PLC controller and converts it into RS-485 signal through its own voltage signal, which is convenient for the subsequent reading of the motor insulation resistance data.

[0038] The resistance insulation tester is connected to the DCS computer, and the DCS computer is connected to the display, and the DCS computer and the display are electrically connected. The resistance insulation tester transmits the detected resistance data to the DCS computer, and then transmits the insulation resistance data to the display through the DCS computer, which is convenient for the staff to view in real time.

[0039] The running contactor KM1 and the resistance detection contactor KM2 can be electrically interlocked through their respective normally closed contacts, so that the running contactor KM1 and the resistance detection contactor KM2 cannot run at the same time. When the running contactor KM1 and the resistance detection contactor KM2 are interlocked, it can be ensured that when the motor is running, the running contactor KM1 is connected and the resistance detection contactor KM2 is disconnected. At this time, the insulation resistance of the motor cannot be detected. At the same time, when detecting the insulation resistance of the motor, the running contactor KM1 is disconnected and the resistance detection contactor KM2 is connected. At this time, the motor cannot be run, thereby ensuring the safety of the staff when detecting the insulation resistance.

[0040] When the resistance insulation tester is powered on to test the insulation resistance of the motor, the motor is in standby mode. For motors that are in standby mode for a long time, inspection personnel can observe the insulation condition of the standby motor at any time to prevent the insulation resistance of the motor from being reduced when it is damp and cannot be discovered in time, resulting in the motor burning out when it is used.

[0041] The working process of the insulation resistance automatic detection system is as follows:

[0042] S1. Assemble the resistance insulation tester inside the motor control circuit, and take AC220V AC power supply on the motor circuit, pass the AC220V AC power supply through the rectifier module, and convert it into DC power supply after passing through the rectifier module. Then, the converted DC power supply is used to power the resistance insulation tester, so that the resistance insulation tester can stably detect the insulation resistance of the motor;

[0043] S2. When the motor is in the standby state, the KA3 relay module is turned on through the SA1 conversion switch. The KA3 relay module is connected to the resistance detection contactor KM2. The resistance detection contactor KM2 triggers the resistance insulation tester to detect the insulation resistance of the motor. The resistance insulation tester transmits the insulation resistance detection data to the PLC controller, and converts it into an RS-485 signal through its own voltage signal, and then transmits it to the DCS computer. The DCS computer displays the resistance value on the display. The inspection personnel can directly know the insulation resistance value of the motor in the standby state through the resistance value on the display; when the motor is in the enabled state, the KA2 relay module is turned on through the SA1 conversion switch. At this time, the KA3 relay module is in the disconnected state, that is, the resistance detection contactor KM2 is in the disconnected state, and the resistance detection contactor KM2 cannot trigger the resistance insulation tester to detect the insulation resistance of the motor. At the same time, the KA2 relay module turns on the running contactor KM1, so that the running contactor KM1 promotes the operation of the motor.

[0044] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0045] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art 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. An automatic insulation resistance detection system, characterized in that: The automatic insulation resistance detection system includes a KA2 relay module, a KA3 relay module and a resistance insulation tester. The KA2 relay module and the KA3 relay module can be connected respectively through the SA1 conversion switch, and the KA3 relay module is connected to the resistance detection contactor KM2, the KA2 relay module is connected to the running contactor KM1, and the running contactor KM1 is connected to the motor, and the resistance detection contactor KM2 is connected to the resistance insulation tester.

2. The automatic insulation resistance detection system according to claim 1, characterized in that: The SA1 switching switch can be connected to the KA2 relay module and the KA3 relay module respectively, and the SA1 switching switch can only be connected to one of the KA2 relay module and the KA3 relay module at a time, and the connection method is electrical connection.

3. The automatic insulation resistance detection system according to claim 1 is characterized in that: The resistance insulation tester can detect the insulation resistance in the motor, and the AC power supply on the motor circuit can be converted through the rectifier module.

4. The automatic insulation resistance detection system according to claim 3 is characterized in that: The rectifier module and the resistance insulation tester can be connected to each other, and the rectifier module and the resistance insulation tester are electrically connected, so that the rectifier module and the resistance insulation tester form a combined component.

5. The automatic insulation resistance detection system according to claim 1 is characterized in that: The resistance insulation tester is connected to the PLC controller, and the resistance insulation tester can convert the detected motor insulation resistance value through its own voltage signal.

6. The automatic insulation resistance detection system according to claim 1, characterized in that: The resistance insulation tester is connected to a DCS computer, and the DCS computer is connected to a display, and the DCS computer and the display are electrically connected.

7. The automatic insulation resistance detection system according to claim 1, characterized in that: The running contactor KM1 and the resistance detection contactor KM2 can be electrically interlocked through their respective normally closed contacts, so that the running contactor KM1 and the resistance detection contactor KM2 cannot operate at the same time.

8. The automatic insulation resistance detection system according to claim 1, characterized in that: When the resistance insulation tester is powered on to test the insulation resistance of the motor, the motor is in a standby state.

9. The automatic insulation resistance detection system according to claim 1, characterized in that: The working process of the insulation resistance automatic detection system is as follows: S1. Assemble the resistance insulation tester inside the motor control circuit, and take AC220V AC power supply on the motor circuit, pass the AC220V AC power supply through the rectifier module, and convert it into DC power supply after passing through the rectifier module. Then, the converted DC power supply is used to power the resistance insulation tester, so that the resistance insulation tester can stably detect the insulation resistance of the motor; S2. When the motor is in the standby state, the KA3 relay module is turned on through the SA1 conversion switch. The KA3 relay module is connected to the resistance detection contactor KM2. The resistance detection contactor KM2 triggers the resistance insulation tester to detect the insulation resistance of the motor. The resistance insulation tester transmits the insulation resistance detection data to the PLC controller, and converts it into an RS-485 signal through its own voltage signal, and then transmits it to the DCS computer. The DCS computer displays the resistance value on the display. The inspection personnel can directly know the insulation resistance value of the motor in the standby state through the resistance value on the display; when the motor is in the enabled state, the KA2 relay module is turned on through the SA1 conversion switch. At this time, the KA3 relay module is in the disconnected state, that is, the resistance detection contactor KM2 is in the disconnected state, and the resistance detection contactor KM2 cannot trigger the resistance insulation tester to detect the insulation resistance of the motor. At the same time, the KA2 relay module turns on the running contactor KM1, so that the running contactor KM1 promotes the operation of the motor.

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