Intelligent maintenance device for low-voltage alternating-current power distribution system

Abstract

The invention belongs to the technical field of automatic detection, and relates to an intelligent maintenance device for a low-voltage AC power distribution system, and the device comprises a customized pressing force sensor which is used for generating a voltage analog signal representing the pressing force of a main contact and transmitting the voltage analog signal to a current transmitter; the alternating-current programmable constant-current power supply is used for outputting preset current to a main contact and an internal main loop of the tested power distribution drawer; the current transmitter is used for acquiring voltage analog signals of each main contact of the tested power distribution drawer and current analog signals flowing into the tested power distribution drawer and transmitting the voltage analog signals and the current analog signals to the analog quantity processing box; the analog quantity processing box is used for converting the voltage analog signal and the current analog signal into digital signals and transmitting the digital signals to the industrial control all-in-one machine through the serial server and the switch; and the industrial control all-in-one machine is used for controlling the alternating-current programmable constant-current power supply to output the preset current, recording and displaying the digital signal and recording the current output time of the alternating-current programmable constant-current power supply. The device is wide in application range, complete in function, high in automation degree and convenient to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of automatic detection, and in particular relates to an intelligent maintenance device for a low-voltage AC power distribution system. Background Art

[0002] The calibration and maintenance of the distribution drawers of the low-voltage AC power distribution system generally includes the calibration and maintenance of the clamping force of the main contacts of the distribution drawers, the calibration and maintenance of the operating current and operating time of the thermal relays inside the distribution drawers, and the calibration and maintenance of the operating current and operating time of the leakage protection relays inside the distribution drawers.

[0003] At present, the calibration and maintenance of the power drawer of the low-voltage AC power distribution system requires the calibration and maintenance personnel to configure a large number of equipment and instruments, and then use wires to connect the equipment and instruments to the drawer to be calibrated and maintained. The calibration and maintenance personnel refer to the test and calibration procedures to manually adjust the equipment and instruments, and manually enter the test data into the table. The calibration process is inefficient and requires high professional and technical level of the calibration and maintenance personnel. The clamping force calibration of the main contacts of the distribution drawer requires the calibration personnel to use a handheld clamping force tester to measure the multiple main contacts of the distribution drawer one by one. An ordinary three-phase distribution drawer needs to be measured at least six times. When testing the clamping force of each contact, it is necessary to repeatedly align the force point of the clamping force tester to avoid large errors in the measurement results. After the measurement is completed, the data needs to be manually recorded and the clamping force of each contact needs to be determined. The measurement and calibration of the clamping force is particularly time-consuming. In addition, since the calibration operation of the distribution drawer thermal relay requires the current connected to the distribution drawer to be as high as hundreds of amperes, the manual calibration operation is very dangerous. With the advancement of automated testing technology, many intelligent maintenance devices for low-voltage AC power distribution systems have been developed, which have improved the automation level of distribution drawer calibration and maintenance to a certain extent. However, these devices generally have the following shortcomings: the calibration and maintenance functions of the devices are incomplete, such as the lack of automatic test and calibration function for the clamping force of the main contacts of the distribution drawer; the degree of automation is not high, and human intervention is still required during the calibration process, making it impossible to complete the test and calibration of the clamping force of the main contacts of the distribution drawer, the test and calibration of the thermal relay, and the test and calibration of the leakage protection relay in the same test slot. Summary of the invention

[0004] The object of the present invention is to provide an intelligent maintenance device for a low-voltage AC power distribution system, which has a wide range of applications, complete functions, a high degree of automation and is easy to operate.

[0005] The technical solution to achieve the purpose of the present invention is:

[0006] An intelligent maintenance device for a low-voltage AC power distribution system, the device comprising:

[0007] A customized clamping force sensor is used to clamp each main contact of the power distribution drawer, generate a voltage analog signal representing the clamping force of the main contact according to the pressure of each main contact of the clamped power distribution drawer, and transmit the voltage analog signal to the current transmitter;

[0008] AC programmable constant current power supply, used to output preset current to the main contacts and internal main circuit of the tested power distribution drawer;

[0009] The current transmitter is used to collect the voltage analog signals of each main contact of the tested distribution drawer and the current analog signals flowing into the tested distribution drawer, and transmit the voltage analog signals of each main contact of the tested distribution drawer and the current analog signals flowing into the tested distribution drawer to the analog quantity processing box;

[0010] The analog quantity processing box is used to convert the voltage analog signal of each main contact of the tested power distribution drawer and the current analog signal of the tested power distribution drawer into digital signals, and transmit the digital signals to the serial port server;

[0011] Serial port server, used to transmit digital signals to industrial control integrated machine through switch;

[0012] The industrial control all-in-one computer is used to control the AC programmable constant current power supply to output a preset current, record and display digital signals, and record the time when the AC programmable constant current power supply outputs current.

[0013] The AC programmable constant current power supply includes a three-phase AC power supply and a single-phase AC power supply; the three-phase AC power supply is used for a three-phase 0-200A AC power supply for thermal relay calibration; the single-phase AC power supply is used for a single-phase 0-10A AC power supply for a leakage protection relay.

[0014] The device also includes a relay matrix, which is used to control the relay to complete the closing and disconnection of the contactor of this circuit, or to control the relay to complete the power supply and disconnection of the auxiliary power supply of this circuit.

[0015] The device also includes a test slot, which is used to accommodate the tested power distribution drawer, and a customized clamping force sensor is installed in the test slot; the test slot includes an 8E / 2 tested device fixing position, a 4E tested device fixing position, a 6E tested device fixing position, and an 8E tested device fixing position.

[0016] The device also includes a power switch button and a power indicator light; the power switch button is used to power on and off the device; the power indicator light is used to indicate whether the device is connected to a working power supply.

[0017] The device also includes a relay base and a banana plug; the relay base is used for checking the corresponding intermediate relay; the banana plug is used for the external transformer interface of the leakage protection relay.

[0018] The industrial control integrated machine comprises:

[0019] User management module, used to set and control the use permissions of administrators and testers;

[0020] DUT management module, used for drawer cabinet management and intermediate relay management;

[0021] Performance test module, used to implement contact tension test, thermal relay calibration, leakage protection relay calibration, and intermediate relay calibration;

[0022] The data management module is used to save test data, test results and reports, view historical data, and export test data, test results and reports.

[0023] The device is used to calibrate the clamping force of the main contacts of the distribution drawer of the low-voltage AC power distribution system: each main contact of the distribution drawer clamps the corresponding customized clamping force sensor of the AC power distribution system intelligent maintenance device, and the strain gauge inside each customized pressure sensor is stressed to generate a corresponding voltage analog signal which is transmitted to the current transmitter. The current transmitter collects the voltage analog signal and transmits it to the analog quantity processing box. The analog quantity processing box processes the voltage analog signal representing the pressure and converts it into a digital signal. The analog quantity processing box transmits the digital signal representing the clamping force of the main contacts to the industrial control integrated machine through the serial port server and the switch. The industrial control integrated machine records and displays the pressure data and judges whether the clamping force is qualified according to the criteria.

[0024] The device is used to calibrate the thermal relay of the power distribution drawer: the industrial control integrated machine of the power distribution drawer controls the AC programmable constant current power supply to output a preset current through the switch, and the current value is the preset action current value of the thermal relay. Since the main contact of the power distribution drawer is stuck with the customized pressure sensor inside the test slot of the low-voltage AC power distribution system intelligent maintenance device at this time, the current output by the AC programmable constant current power supply is connected to the main contact and the internal main circuit of the tested power distribution drawer through the contactor and the shell of the customized pressure sensor, and the industrial control integrated machine records the time when the AC programmable constant current power supply outputs the current; at the same time, the current transmitter collects the current analog signal flowing into the tested power distribution drawer and transmits it to the analog quantity processing box, the analog quantity processing box processes the current analog signal and converts it into a digital signal, and the analog quantity processing box transmits the digital signal to the industrial control integrated machine through the serial port server and the switch; when the thermal relay of the power distribution drawer is actuated, that is, the main circuit is disconnected, the industrial control integrated machine detects that the current drops to zero through the current transmitter, stops timing, and obtains the action current and action time of the thermal relay.

[0025] The device is used to calibrate the leakage protection relay of the distribution drawer: the industrial control integrated machine of the distribution drawer controls the AC programmable constant current power supply to output a preset three-phase unbalanced current through a switch, the sum of the three-phase currents is the preset action value of the leakage protection relay, the current is connected to the main contacts and the internal leakage protection relay of the distribution drawer under test through the customized pressure sensor shell, and the industrial control integrated machine software records the time when the AC programmable constant current power supply outputs the current; at the same time, the current transmitter collects the current analog signal flowing into the distribution drawer under test and transmits it to the analog quantity processing box, the analog quantity processing box converts the current analog quantity signal into a digital signal and transmits it to the serial port server, and the serial port server then transmits the digital signal to the industrial control integrated machine through the switch; when the leakage protection relay of the distribution drawer is activated, the industrial control integrated machine detects that the current drops to zero through the current transmitter, stops timing, and obtains the action current and action time of the leakage protection relay.

[0026] The beneficial technical effects of the present invention are:

[0027] 1. The present invention provides an intelligent maintenance device for a low-voltage AC power distribution system, which can automatically complete the thermal relay verification, leakage protection relay verification, and main contact clamping force verification of the power distribution drawer.

[0028] 2. By using the intelligent maintenance device for a low-voltage AC power distribution system provided by the present invention, the entire verification process is completed in one test slot, without the need to move the drawer being verified multiple times. It is convenient and fast, and a verification report is automatically generated and the verification data records are stored in a database, which is convenient for data statistical analysis.

[0029] 3. The industrial control integrated machine detection software in the low-voltage AC power distribution system intelligent maintenance device provided by the present invention has a user-friendly interface, simple operation and easy use. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of an intelligent maintenance device for a low-voltage AC power distribution system provided by the present invention;

[0031] Figure 2 A block diagram of an intelligent maintenance device for a low-voltage AC power distribution system provided by the present invention;

[0032] Figure 3 A schematic diagram of the main contact clamping force verification of a power distribution drawer using a low-voltage AC power distribution system intelligent maintenance device provided by the present invention;

[0033] Figure 4 A low-voltage AC power distribution system intelligent maintenance device provided by the present invention is used for the thermal relay verification principle diagram of the power distribution drawer;

[0034] Figure 5A schematic diagram of the calibration of a leakage protection relay of a power distribution drawer for a low-voltage AC power distribution system intelligent maintenance device provided by the present invention;

[0035] Figure 6 The present invention provides a schematic block diagram of an industrial control integrated machine in an intelligent maintenance device for a low-voltage AC power distribution system.

[0036] In the figure: 1. Touch display; 2. Power switch button; 3. Power indicator light; 4. Relay base; 5. Banana plug; 6. 8E / 2 DUT fixing position; 7. 4E DUT fixing position; 8. 6E DUT fixing position; 9. 8E DUT fixing position; 10. Single-phase AC power supply; 11. Three-phase AC power supply. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0038] The present invention provides an intelligent maintenance device for a low-voltage AC power distribution system, comprising: a customized clamping force sensor, an AC programmable constant current power supply, a current transmitter, an analog quantity processing box, a serial port server, a switch, and an industrial control all-in-one machine.

[0039] A customized clamping force sensor is used to clamp each main contact of the power distribution drawer, generate a voltage analog signal representing the clamping force of the main contact according to the pressure of each main contact of the clamped power distribution drawer, and transmit the voltage analog signal to the current transmitter;

[0040] AC programmable constant current power supply, used to output preset current to the main contacts and internal main circuit of the tested power distribution drawer;

[0041] The current transmitter is used to collect the voltage analog signals of each main contact of the tested distribution drawer and the current analog signals flowing into the tested distribution drawer, and transmit the voltage analog signals of each main contact of the tested distribution drawer and the current analog signals flowing into the tested distribution drawer to the analog quantity processing box;

[0042] The analog quantity processing box is used to convert the voltage analog signal of each main contact of the tested power distribution drawer and the current analog signal of the tested power distribution drawer into digital signals, and transmit the digital signals to the serial port server;

[0043] Serial port server, used to transmit digital signals to industrial control integrated machine through switch;

[0044] The industrial control all-in-one computer is used to control the AC programmable constant current power supply to output a preset current, record and display digital signals, and record the time when the AC programmable constant current power supply outputs current.

[0045] The AC programmable constant current power supply includes a three-phase AC power supply 11 and a single-phase AC power supply 10; the three-phase AC power supply 11 is used as a three-phase 0-200A AC power supply for thermal relay calibration; the single-phase AC power supply 10 is used as a single-phase 0-10A AC power supply for leakage protection relays. Figure 1 shown.

[0046] The device of the present invention also includes a relay matrix, which is used to control the relay to complete the closing and disconnection of the contactor of this circuit, or to control the relay to complete the power supply and disconnection of the auxiliary power supply of this circuit.

[0047] like Figure 1 As shown, the device of the present invention includes a test slot, which is used to accommodate the power distribution drawer under test, and the customized clamping force sensor is installed in the test slot. The test slot includes an 8E / 2 test piece fixing position 6, a 4E test piece fixing position 7, a 6E test piece fixing position 8, and an 8E test piece fixing position 9. The 8E / 2 test piece fixing position 6 is used to fix the 8E / 2 test piece for testing; the 4E test piece fixing position 7 is used to fix the 4E test piece for testing; the 6E test piece fixing position 8 is used to fix the 6E test piece for testing; and the 8E test piece fixing position 9 is used to fix the 8E test piece for testing.

[0048] like Figure 1 As shown, the device of the present invention further comprises a power switch button 2 and a power indicator light 3; the power switch button 2 is used to power on and off the device; the power indicator light 3 is used to indicate whether the device is connected to a working power supply.

[0049] like Figure 1 As shown, the device of the present invention further comprises a relay base 4 and a banana plug 5; the relay base 4 is used for checking the corresponding intermediate relay; the banana plug 5 is used for the external transformer interface of the leakage protection relay.

[0050] like Figure 1 As shown, the industrial control all-in-one machine in the device of the present invention is a touch display 1.

[0051] In a specific embodiment, the present invention provides a low-voltage AC power distribution system intelligent maintenance device, including: an industrial control integrated machine, 2 analog acquisition modules, an AC programmable constant current power supply, 3 contactors, 3 current transmitters, 18 customized pressure sensors, 3 AC contactors, power relays, DC power supplies, serial port servers, switches, cabinets, such as Figure 2 shown.

[0052] The low-voltage AC power distribution system intelligent maintenance device provided by the present invention is used to perform maintenance on the low-voltage AC power distribution system. When the verification and maintenance begins, the distribution drawer to be verified is loaded into a test slot of the low-voltage AC power distribution system intelligent maintenance device, and the main contact of the distribution drawer is stuck with the customized clamping force sensor installed in the test slot of the low-voltage AC power distribution system intelligent maintenance device. The verification can be started by starting the verification through the industrial control integrated machine to automatically carry out each verification item one by one.

[0053] A low-voltage AC power distribution system intelligent maintenance device provided by the present invention is used to calibrate the clamping force of the main contacts of the distribution drawer of the low-voltage AC power distribution system: each main contact of the distribution drawer is clamped by a corresponding customized clamping force sensor of the AC power distribution system intelligent maintenance device, and the strain gauge inside each customized pressure sensor is stressed to generate a corresponding voltage analog signal which is transmitted to the current transmitter. The current transmitter collects the voltage analog signal and transmits it to an analog quantity processing box. The analog quantity processing box processes the voltage analog signal representing the pressure and converts it into a digital signal. The analog quantity processing box transmits the digital signal representing the clamping force of the main contacts to the industrial control integrated machine through the serial port server and the switch. The industrial control integrated machine records and displays the pressure data and determines whether the clamping force is qualified according to the criteria.

[0054] like Figure 3 As shown, the test principle and process of using a low-voltage AC power distribution system intelligent maintenance device provided by the present invention to perform a main contact clamping force calibration of a power distribution drawer are as follows:

[0055] Step 1. Insert the drawer into the test slot;

[0056] Step 2: Use the preset parameters of the industrial computer, including setting or selecting the test drawer type, and start the test;

[0057] Step 3: The industrial computer sends a read command through the LAN port according to the preset parameters, and the transmitter collects the voltage signal generated by the customized pressure sensor at this time;

[0058] Step 4: The industrial control integrated machine converts the voltage signal data collected by the transmitter into a digital signal corresponding to the actual contact tension through the analog quantity processing box, and the analog quantity processing box transmits the digital signal to the industrial control integrated machine through the serial port server and the switch;

[0059] Step 5: The industrial computer displays the test force value and records it in the test report;

[0060] Step 6: When the test is completed, remove the drawer from the test slot or continue with other test items.

[0061] A low-voltage AC power distribution system intelligent maintenance device provided by the present invention is used to calibrate the thermal relay of a distribution drawer: the industrial control integrated machine of the distribution drawer controls the AC programmable constant current power supply to output a preset current through a switch, and the current value is the preset action current value of the thermal relay. Since the main contact of the distribution drawer is stuck to the customized pressure sensor inside the test slot of the low-voltage AC power distribution system intelligent maintenance device at this time, the current output by the AC programmable constant current power supply is connected to the main contact and the internal main circuit of the tested distribution drawer through the contactor and the shell of the customized pressure sensor, and the industrial control integrated machine records the time when the AC programmable constant current power supply outputs the current; at the same time, the current transmitter collects the current analog signal flowing into the tested distribution drawer and transmits it to the analog quantity processing box, the analog quantity processing box processes the current analog signal and converts it into a digital signal, and the analog quantity processing box transmits the digital signal to the industrial control integrated machine through the serial port server and the switch; when the thermal relay of the distribution drawer is actuated, that is, the main circuit is disconnected, the industrial control integrated machine detects that the current drops to zero through the current transmitter, stops timing, and obtains the action current and action time of the thermal relay.

[0062] like Figure 4 As shown, the test principle and process of the thermal relay calibration of the power distribution drawer using a low-voltage AC power distribution system intelligent maintenance device provided by the present invention are as follows:

[0063] Step 1. Insert the drawer into the test slot;

[0064] Step 2: Use the industrial computer to preset parameters, including setting or selecting the test drawer type and the thermal relay calibration current, and start the test;

[0065] Step 3: The industrial computer sends the current setting value to the three-phase AC power supply through the LAN port according to the preset parameters, and then controls the relay through the relay matrix to complete the closing of the contactor of this circuit;

[0066] Step 4: The industrial computer starts the three-phase AC power supply through the LAN port to provide a large current to the drawer and starts timing. At the same time, the Hall current transmitter and the analog acquisition card continuously collect current values ​​and transmit them to the industrial computer.

[0067] Step 5: The high current continues until the drawer thermal relay operates, the drawer circuit breaker disconnects the test main circuit, the current becomes zero, and the industrial computer records the moment when the current is disconnected;

[0068] Step 6: Timing to obtain the action time of the thermal relay, and generating test results and reports;

[0069] Step 7: After the test is completed, the industrial control integrated machine controls the relay through the LAN port and the relay matrix to disconnect the contactor of this circuit;

[0070] Step 8: The industrial computer displays that the test is complete. Pull out the drawer from the test slot or continue with other test items.

[0071] A low-voltage AC power distribution system intelligent maintenance device provided by the present invention is used to calibrate the leakage protection relay of the distribution drawer: the industrial control integrated machine of the distribution drawer controls the AC programmable constant current power supply to output a preset three-phase unbalanced current through a switch, the sum of the three-phase currents is the preset action value of the leakage protection relay, the current is connected to the main contacts and the internal leakage protection relay of the tested distribution drawer through a customized pressure sensor housing, and the industrial control integrated machine software records the time when the AC programmable constant current power supply outputs the current; at the same time, the current transmitter collects the current analog signal flowing into the tested distribution drawer and transmits it to the analog quantity processing box, the analog quantity processing box converts the current analog signal into a digital signal and transmits it to the serial port server, and the serial port server then transmits the digital signal to the industrial control integrated machine through the switch; when the leakage protection relay of the distribution drawer is activated, the industrial control integrated machine detects that the current drops to zero through the current transmitter, stops timing, and obtains the action current and action time of the leakage protection relay.

[0072] like Figure 5 As shown, the test principle and process of calibrating the leakage protection relay of the power distribution drawer by using a low-voltage AC power distribution system intelligent maintenance device provided by the present invention are as follows:

[0073] Step 1. Insert the drawer into the test slot;

[0074] Step 2: Use the transformer test cable to connect the leakage current transformer to the signal interface on the cabinet;

[0075] Step 3, using the industrial computer to preset parameters, the preset parameters include setting or selecting the test drawer type and the calibration current of the leakage current transformer, and starting the test;

[0076] Step 4: The industrial computer sends the current setting value to the single-phase AC power supply through the LAN port according to the preset parameters, and controls the relay through the LAN port and the relay matrix to complete the auxiliary power supply of this circuit;

[0077] Step 5: The industrial computer starts the single-phase AC power supply through the LAN port to provide current to the drawer and starts timing. At the same time, the Hall current transmitter and the analog acquisition card continuously and uninterruptedly collect the current value and the on-off status of the main circuit and transmit them to the industrial computer;

[0078] Step 6: The current continues until the drawer leakage protection relay is activated, the drawer circuit breaker disconnects the test main circuit, the main circuit is in a disconnected state, and the industrial control integrated computer records the time when the main circuit is disconnected;

[0079] Step 7: timing to obtain the action time and action current of the leakage protection relay, and generating test results and reports;

[0080] Step 8: After the test is completed, the industrial control integrated machine controls the relay through the LAN port and the relay matrix to disconnect the auxiliary power supply of this circuit;

[0081] Step 9: When the industrial computer displays that the test is complete, remove the drawer from the test slot and disconnect the leakage current transformer wiring.

[0082] The industrial control integrated machine uses Windows operating system and LabView as the development environment. The industrial control integrated machine includes: user management module, device under test management module, performance test module, data management module, such as Figure 6 shown.

[0083] The user management module is used to set and control the usage permissions of administrators and testers;

[0084] The DUT management module is used for drawer cabinet management and intermediate relay management;

[0085] The performance test module is used to implement contact tension test, thermal relay calibration, leakage protection relay calibration, and intermediate relay calibration;

[0086] The data management module is used to save test data, test results and reports, view historical data, and export test data, test results and reports.

[0087] The low-voltage AC power distribution system intelligent maintenance device provided by the present invention is used to perform intelligent maintenance of the low-voltage AC power distribution system, which specifically includes the following steps:

[0088] Step 1: Turn on the computer

[0089] Press the power button on the console. The maintenance device is powered on and the login interface is displayed on the screen of the industrial computer.

[0090] Step 2: Log in to your account

[0091] Log in using the account and password assigned by the administrator. Enter the account and password, and after logging in, you can complete your basic personal information in the user settings.

[0092] Step 3: Insert the DUT

[0093] Depending on whether the device under test is a drawer cabinet or an intermediate relay, select the corresponding interface position for insertion. The drawer cabinet is inserted into the interface of matching specifications at the bottom, and the intermediate relay is inserted into the intermediate relay base on the upper right.

[0094] Step 4: Automatic detection

[0095] Enter the performance test interface, select the model of the device under test by pulling down, and click "Start Detection" with the mouse. The system will automatically start comprehensive detection according to the test case. The system will apply corresponding stimuli to the input in turn and measure the output results. The detection process will display the progress of the detection completion and the current test item information.

[0096] Step 5: Generate report

[0097] After the comprehensive test is completed, the test result data can be automatically generated into a word version test report, which can be connected to a printer to print the word version report on A4 paper; or it can be exported using the USB interface.

[0098] Step 6: End shutdown

[0099] After the detection is completed, remove the power distribution drawer or intermediate relay, click the shutdown button on the software interface to shut down the system computer, and press the table power switch to cut off the power supply of the detection system.

[0100] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. The contents not described in detail in the present invention can adopt the existing technology.

Claims

1. An intelligent maintenance device for a low voltage AC power distribution system, characterized in that: The device comprises: A customized clamping force sensor is used to clamp each main contact of the power distribution drawer, generate a voltage analog signal representing the clamping force of the main contact according to the pressure of each main contact of the clamped power distribution drawer, and transmit the voltage analog signal to the current transmitter; AC programmable constant current power supply, used to output preset current to the main contacts and internal main circuit of the tested power distribution drawer; The current transmitter is used to collect the voltage analog signals of each main contact of the tested distribution drawer and the current analog signals flowing into the tested distribution drawer, and transmit the voltage analog signals of each main contact of the tested distribution drawer and the current analog signals flowing into the tested distribution drawer to the analog quantity processing box; The analog quantity processing box is used to convert the voltage analog signal of each main contact of the tested power distribution drawer and the current analog signal of the tested power distribution drawer into digital signals, and transmit the digital signals to the serial port server; Serial port server, used to transmit digital signals to industrial control integrated machine through switch; The industrial control all-in-one computer is used to control the AC programmable constant current power supply to output a preset current, record and display digital signals, and record the time when the AC programmable constant current power supply outputs current.

2. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The AC programmable constant current power supply includes a three-phase AC power supply and a single-phase AC power supply; the three-phase AC power supply is used for a three-phase 0-200A AC power supply for thermal relay calibration; the single-phase AC power supply is used for a single-phase 0-10A AC power supply for a leakage protection relay.

3. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The device also includes a relay matrix, which is used to control the relay to complete the closing and disconnection of the contactor of this circuit, or to control the relay to complete the power supply and disconnection of the auxiliary power supply of this circuit.

4. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The device also includes a test slot, which is used to accommodate the tested power distribution drawer, and a customized clamping force sensor is installed in the test slot; the test slot includes an 8E / 2 tested device fixing position, a 4E tested device fixing position, a 6E tested device fixing position, and an 8E tested device fixing position.

5. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The device also includes a power switch button and a power indicator light; the power switch button is used to power on and off the device; the power indicator light is used to indicate whether the device is connected to a working power supply.

6. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The device also includes a relay base and a banana plug; the relay base is used for checking the corresponding intermediate relay; the banana plug is used for the external transformer interface of the leakage protection relay.

7. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The industrial control integrated machine comprises: User management module, used to set and control the use permissions of administrators and testers; DUT management module, used for drawer cabinet management and intermediate relay management; Performance test module, used to implement contact tension test, thermal relay calibration, leakage protection relay calibration, and intermediate relay calibration; The data management module is used to save test data, test results and reports, view historical data, and export test data, test results and reports.

8. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The device is used to calibrate the clamping force of the main contacts of the distribution drawer of the low-voltage AC power distribution system: each main contact of the distribution drawer clamps the corresponding customized clamping force sensor of the AC power distribution system intelligent maintenance device, and the strain gauge inside each customized pressure sensor is stressed to generate a corresponding voltage analog signal which is transmitted to the current transmitter. The current transmitter collects the voltage analog signal and transmits it to the analog quantity processing box. The analog quantity processing box processes the voltage analog signal representing the pressure and converts it into a digital signal. The analog quantity processing box transmits the digital signal representing the clamping force of the main contacts to the industrial control integrated machine through the serial port server and the switch. The industrial control integrated machine records and displays the pressure data and judges whether the clamping force is qualified according to the criteria.

9. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The device is used to calibrate the thermal relay of the power distribution drawer: the industrial control integrated machine of the power distribution drawer controls the AC programmable constant current power supply to output a preset current through the switch, and the current value is the preset action current value of the thermal relay. Since the main contact of the power distribution drawer is stuck with the customized pressure sensor inside the test slot of the low-voltage AC power distribution system intelligent maintenance device at this time, the current output by the AC programmable constant current power supply is connected to the main contact and the internal main circuit of the tested power distribution drawer through the contactor and the shell of the customized pressure sensor, and the industrial control integrated machine records the time when the AC programmable constant current power supply outputs the current; at the same time, the current transmitter collects the current analog signal flowing into the tested power distribution drawer and transmits it to the analog quantity processing box, the analog quantity processing box processes the current analog signal and converts it into a digital signal, and the analog quantity processing box transmits the digital signal to the industrial control integrated machine through the serial port server and the switch; when the thermal relay of the power distribution drawer is actuated, that is, the main circuit is disconnected, the industrial control integrated machine detects that the current drops to zero through the current transmitter, stops timing, and obtains the action current and action time of the thermal relay.

10. The low voltage AC power distribution system intelligent maintenance device according to claim 1, characterized in that: The device is used to calibrate the leakage protection relay of the distribution drawer: the industrial control integrated machine of the distribution drawer controls the AC programmable constant current power supply to output a preset three-phase unbalanced current through a switch, the sum of the three-phase currents is the preset action value of the leakage protection relay, the current is connected to the main contacts and the internal leakage protection relay of the distribution drawer under test through the customized pressure sensor shell, and the industrial control integrated machine software records the time when the AC programmable constant current power supply outputs the current; at the same time, the current transmitter collects the current analog signal flowing into the distribution drawer under test and transmits it to the analog quantity processing box, the analog quantity processing box converts the current analog quantity signal into a digital signal and transmits it to the serial port server, and the serial port server then transmits the digital signal to the industrial control integrated machine through the switch; when the leakage protection relay of the distribution drawer is activated, the industrial control integrated machine detects that the current drops to zero through the current transmitter, stops timing, and obtains the action current and action time of the leakage protection relay.

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