Automatic detection system of low-voltage electric appliance cabinet

Abstract

The utility model provides an automatic detection system of a low-voltage electric appliance cabinet, which belongs to the field of alternating-current locomotive detection and comprises an industrial personal computer, a control unit, an insulation and line sequence detection unit, a resistance and action detection unit, an energy consumption meter detection unit and a withstand voltage test unit. The industrial personal computer is used for sending a detection instruction to the control unit; and the control unit is used for sending a detection instruction to the insulation and line sequence detection unit, the resistance and action detection unit, the energy consumption meter detection unit and the withstand voltage test unit, and controlling each unit to realize a corresponding detection function. The system can automatically perform various detections on thousands of lines in the low-voltage electrical cabinet, solves the problems of informatization lag, excessive dependence on personnel experience, lack of automatic test equipment and insufficient test data accumulation in the detection and maintenance of the low-voltage electrical cabinet of the current alternating-current locomotive, reduces the maintenance period of the low-voltage electrical cabinet, and improves the maintenance efficiency of the low-voltage electrical cabinet. The human error probability is reduced, and the detection automation level and reliability are improved.

Description

Technical Field

[0001] The present application belongs to the field of AC locomotive detection, and specifically relates to an automatic detection system for a low-voltage electrical cabinet. Background Art

[0002] The low-voltage electrical cabinet is the carrier of various electrical equipment and microcomputer network control systems in the main circuit, auxiliary circuit and control circuit of the AC locomotive. It is an important part of the locomotive control system. It has a large number of lines and complex logic. When the low-voltage electrical cabinet is shipped or repaired, it is a heavy and important task to detect its wiring logic, insulation condition, withstand voltage performance and contact resistance. At present, there are problems such as lagging in information technology, over-reliance on personnel experience, lack of automated testing equipment, and insufficient accumulation of test data in the inspection and maintenance of locomotive electrical cabinets. The main problems are as follows:

[0003] (1) The use of manual detection and manual judgment results leads to low troubleshooting efficiency. For example, in the wiring logic detection process, operators need to check thousands of wires one by one. This is a huge workload and inefficient, which can easily cause visual fatigue and seriously affect work efficiency. If there is an abnormal interaction between device signals, it cannot be directly extracted and the inspectors cannot quickly find the cause of the problem.

[0004] (2) The test methods are primitive and the technical level of operators is high, which restricts the improvement of production capacity. The main processes of the electrical cabinet test are all manually operated and inspected by naked eyes. Various inspection items require multiple equipment and instruments to test. Different operation methods, inspection positions and viewing angles will affect the accuracy of the results. The test results are completely dependent on the technical level of the operators. The training of operators mainly relies on the training method of master-apprentice combined with on-site operation. The training cycle is long and the output quality cannot be guaranteed during the training process.

[0005] (3) A unified and complete information management system has not yet been established. Currently, test reports are recorded and stored in paper form, which is not convenient for data review and transmission, is not conducive to the tracking and management of locomotive quality throughout its life cycle, and cannot provide historical traceability functions.

[0006] Based on the above problems, there is an urgent need for an automatic detection system for low-voltage electrical cabinets in AC locomotives, which can not only complete automatic functional detection of wiring logic, insulation performance, withstand voltage performance, contact resistance, relay action, etc., but also reduce the probability of human error, improve the automation level and reliability of maintenance, and reduce the maintenance cycle of low-voltage electrical cabinets. Utility Model Content

[0007] Based on the above technical problems, the present application proposes an automatic detection system for a low-voltage electrical cabinet, including: an industrial computer, a control unit, an insulation and line sequence detection unit, a resistance and action detection unit, an energy consumption meter detection unit, and a withstand voltage test unit;

[0008] The industrial computer is connected to the control unit and is used to send a detection instruction to the control unit;

[0009] The control unit is connected to the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit, respectively, and is used to send detection instructions to the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit;

[0010] The insulation and line sequence detection unit is connected to the cables in the multiple cages and is used to perform insulation and line sequence detection on the cables in the multiple cages;

[0011] The resistance and action detection unit is connected to the contact resistance of the relay in the low-voltage electrical cabinet and is used to detect the contact resistance value of the relay in the low-voltage electrical cabinet and whether the relay action meets the requirements;

[0012] The energy consumption meter detection unit is connected to the load and is used to detect the actual power consumption of the load;

[0013] The withstand voltage test unit is connected to the cables in the multiple cages and is used to perform withstand voltage test on the cables in the multiple cages.

[0014] The cage is provided with cables with the same function and / or wiring mode as those in the low-voltage electrical cabinet.

[0015] The insulation and line sequence detection unit includes: an insulation detection subunit, and the insulation detection subunit includes: a high-voltage circuit board, a low-voltage circuit board, a low-voltage generator, a high-voltage generator, a first switch, a second switch, a voltage monitoring circuit, a first single-chip microcomputer, a resistance acquisition submodule, a first input switching array, and a first output switching array;

[0016] The input end of the first input switching array and the output end of the first output switching array are respectively connected to the cables in the cage, the output end of the first input switching array is connected to the input end of the resistance acquisition submodule, the output end of the resistance acquisition submodule is connected to the first input end of the first single-chip microcomputer, the second input end of the first single-chip microcomputer is connected to the output end of the voltage monitoring circuit, the output end of the first single-chip microcomputer is respectively connected to the input end of the high-voltage circuit board and the input end of the low-voltage circuit board, the output end of the high-voltage circuit board is connected to the input end of the high-voltage generator, the output end of the low-voltage circuit board is connected to the input end of the low-voltage generator, the output end of the high-voltage generator and the output end of the low-voltage generator are respectively connected to the input end of the first switching switch, the output end of the first switching switch is connected to the input end of the second switching switch, the output end of the second switching switch is connected to the input end of the first output switching array, the output end of the high-voltage generator is connected to the first input of the voltage monitoring circuit, the output end of the first switching switch is connected to the second input end of the voltage monitoring circuit, the output end of the second switching switch is connected to the third input end of the voltage monitoring circuit, and the first single-chip microcomputer communicates with the control unit.

[0017] The insulation and line sequence detection unit further comprises: a line sequence detection subunit, the line sequence detection subunit comprises: a switching relay, a protection resistor and a photoelectric coupler;

[0018] One end of the cable to be detected in the cage is connected to the first end of the switching relay, the second end of the switching relay is connected to the first end of the protective resistor, the second end of the protective resistor is connected to the first input end of the photoelectric coupler, the first output end of the photoelectric coupler is connected to the input end of the control unit, the low-voltage circuit board is connected to the first end of the coil of the switching relay, the second end of the coil of the switching relay is grounded, the second input end of the photoelectric coupler is grounded, and the second output end of the photoelectric coupler is grounded.

[0019] The resistor and action detection unit includes: an action voltage board, a third switch, a fourth switch, a voltage detection board, a second single chip microcomputer, a milliohm detection subunit, a second output switch array, a second input switch array and a fifth switch;

[0020] The first output end of the action voltage board is connected to the first input end of the third switch, the second output end of the action voltage board is connected to the second input end of the third switch, the output end of the third switch is respectively connected to the input end of the fourth switch and the first end of the voltage detection board, the output end of the fourth switch is respectively connected to the second end of the voltage detection board and the first end of the second output switching array, the third end of the voltage detection board is connected to the first end of the second single-chip microcomputer, the second end of the second single-chip microcomputer is connected to the first end of the milliohm detection subunit, the second end of the milliohm detection subunit is connected to the second end of the second output switching array, the third end of the second single-chip microcomputer is connected to the third end of the second output switching array, the fourth end of the second single-chip microcomputer is connected to the first end of the second input switching array, the fourth end of the second output switching array is connected to the first end of the fifth switch, the second end of the fifth switch is connected to the third end of the second input switching array, the third end of the fifth switch is connected to the relay access cable in the low-voltage electrical cabinet, and the second single-chip microcomputer communicates with the control unit.

[0021] The energy consumption meter detection unit comprises: a switchboard, a transformer coupling circuit and an energy consumption meter;

[0022] The output end of the switchboard is connected to the input end of the transformer coupling, and the output end of the transformer coupling is connected to the input end of the energy consumption meter;

[0023] The switchboard is used to output a preset voltage and current;

[0024] The transformer coupling circuit is used to input the voltage and current of the simulated load into the energy consumption meter;

[0025] The energy consumption meter is used to display the corresponding energy consumption value based on the voltage and current of the simulated load.

[0026] The switchboard comprises: an AC power supply, a sixth switch and a voltage and current output submodule;

[0027] The output end of the AC power supply is connected to the first end of the sixth switch, the second end of the sixth switch is connected to the input end of the transformer coupling circuit, and the third end of the sixth switch is connected to the input end of the voltage and current output submodule.

[0028] The transformer coupling circuit comprises: a voltage transformer, a current transformer and a simulated load;

[0029] The second end of the sixth switching switch is respectively connected to the input end of the voltage transformer and the input end of the current transformer, the output end of the voltage transformer is connected to the first input end of the energy consumption meter, the output end of the current transformer is connected to the second input end of the energy consumption meter, and the simulated load is connected in series to the input end of the current transformer.

[0030] The withstand voltage test unit includes: a third single chip microcomputer, a withstand voltage test control board, a withstand voltage generator, a seventh switch, an eighth switch and a voltage monitoring circuit;

[0031] The input end of the withstand voltage test control board is connected to the control end of the third single-chip microcomputer, the output end of the withstand voltage test control board is connected to the input end of the withstand voltage generator, the output end of the withstand voltage generator is connected to the first end of the seventh switch, the second end of the seventh switch is respectively connected to the first end of the voltage monitoring circuit and the first end of the eighth switch, the second end of the eighth switch is respectively connected to the second end of the voltage monitoring circuit and the cable to be detected in the cage, and the cable to be detected in the cage is connected to the test end of the withstand voltage test control board. The third single-chip microcomputer communicates with the control unit.

[0032] The control unit, insulation and line sequence detection unit, resistance and action detection unit, energy consumption meter detection unit and withstand voltage test unit are all placed in a control cabinet.

[0033] Beneficial effects:

[0034] The present application proposes an automatic detection system for low-voltage electrical cabinets, which can automatically perform various detections on thousands of lines in the low-voltage electrical cabinets, solving the current problems of information lag, over-reliance on personnel experience, lack of automated testing equipment, and insufficient accumulation of test data in the detection and maintenance of low-voltage electrical cabinets for AC locomotives. The system shortens the maintenance cycle of low-voltage electrical cabinets, reduces the probability of human error, and improves the level of detection automation and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a principle block diagram of the automatic detection system of the low-voltage electrical cabinet of the embodiment of the present application;

[0036] Figure 2 This is a principle block diagram of the insulation detection subunit of an embodiment of the present application;

[0037] Figure 3 This is a principle block diagram of a line sequence detection subunit according to an embodiment of the present application;

[0038] Figure 4 This is a principle block diagram of a resistor and an action detection unit according to an embodiment of the present application;

[0039] Figure 5 This is a principle block diagram of an energy consumption meter detection unit according to an embodiment of the present application;

[0040] Figure 6 This is a principle block diagram of a withstand voltage test unit according to an embodiment of the present application;

[0041] Figure 7 This is a flow chart of automatic detection of a low-voltage electrical cabinet according to an embodiment of the present application;

[0042] Figure 8 This is a schematic diagram of the withstand voltage test parameter interface of an embodiment of the present application;

[0043] Fig. 9 This is a schematic diagram of the insulation parameter test interface of an embodiment of the present application;

[0044] Fig.10 A schematic diagram of contact resistance test parameter configuration according to an embodiment of the present application;

[0045] Fig.11 This is a schematic diagram of the relay action voltage configuration according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] The present disclosure is further described below in conjunction with the embodiments shown in the accompanying drawings.

[0047] There are more than 1,000 cables in the low-voltage electrical cabinet of an AC locomotive. If the manual judgment method is directly used, the troubleshooting efficiency is low. However, if you want to use an automatic method to detect more than 1,000 cables, it is not an easy task. If you directly add detection devices and corresponding loops in the low-voltage electrical cabinet of an AC locomotive, it is bound to increase the design complexity of the low-voltage electrical cabinet of an AC locomotive and reduce the reliability of the low-voltage electrical cabinet of an AC locomotive. Therefore, this application classifies more than 1,000 cables in the low-voltage electrical cabinet of an AC locomotive according to wiring functions and wiring methods, and each category is grouped together as a cage, which is convenient for test control and test wiring. The cables in multiple cages are connected to the test cable interface in the control cabinet, and various test devices and corresponding loops are set in the control cabinet. In this way, on the one hand, the classification method of the cables in the cage can be improved to improve the test efficiency, and on the other hand, the various test devices and corresponding loops in the control cabinet can be improved to improve the test effect. Both improvements do not affect the devices inside the low-voltage electrical cabinet of an AC locomotive, and the reliability of the low-voltage electrical cabinet of an AC locomotive is guaranteed.

[0048] Example:

[0049] This embodiment provides an automatic detection system for a low-voltage electrical cabinet, such as Figure 1 As shown, it includes: an industrial computer, a control unit, an insulation and line sequence detection unit, a resistance and action detection unit, an energy consumption meter detection unit and a withstand voltage test unit;

[0050] The industrial computer is connected to the control unit and is used to send a detection instruction to the control unit;

[0051] The control unit is connected to the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit, respectively, and is used to send detection instructions to the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit;

[0052] The insulation and line sequence detection unit is connected to the cables in the multiple cages and is used to perform insulation and line sequence detection on the cables in the multiple cages;

[0053] The resistance and action detection unit is connected to the contact resistance of the relay in the low-voltage electrical cabinet and is used to detect the contact resistance value of the relay in the low-voltage electrical cabinet and whether the relay action meets the requirements;

[0054] The energy consumption meter detection unit is connected to the load and is used to detect the actual power consumption of the load;

[0055] The withstand voltage test unit is connected to the cables in the multiple cages and is used to perform withstand voltage test on the cables in the multiple cages.

[0056] In this embodiment, the automatic detection system of the low-voltage electrical cabinet is connected to the object to be tested through cables in multiple cages, wherein the object to be tested is an AC locomotive low-voltage electrical cabinet, and the automatic detection system of the low-voltage electrical cabinet includes an industrial computer, a control cabinet, and a test cable interface; wherein the control unit, the insulation and line sequence detection unit, the resistance and action detection unit, the energy consumption meter detection unit, and the withstand voltage test unit are all placed in the control cabinet. More than 1,000 cables in the AC locomotive low-voltage electrical cabinet are classified according to wiring function and wiring method, and each category is collectively referred to as a cage, and more than 1,000 cables are summarized into cages 1 to cages N, wherein N is an integer less than or equal to 1,000. The cables in multiple cages are connected to the test cable interface in the control cabinet, and the control unit, the insulation and line sequence detection unit, the resistance and action detection unit, the energy consumption meter detection unit, and the withstand voltage test unit in the control cabinet are used to test the cables in the multiple cages to obtain insulation and line sequence test results, resistance and action test results, energy consumption test results, and withstand voltage test results. Among them, the industrial computer is used for data transmission between the control cabinet and the control cabinet, mainly for sending various detection instructions to the control unit in the control cabinet; the control cabinet is used for data transmission between the test cable interface; the system test cable interface is used to connect cables in multiple cages.

[0057] The control cabinet includes: a control unit, an insulation and line sequence detection unit, a resistance and motion detection unit, an energy consumption meter detection unit and a withstand voltage test unit; the industrial computer completes data transmission with the control unit through a serial field bus; the control unit transmits data with the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit respectively;

[0058] In this embodiment, a communication control module should also be included between the control unit and the insulation and wire sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit, for data transmission between the control unit and the insulation and wire sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit, and the communication control module is a communication interface device.

[0059] The insulation and line sequence detection unit, such as Figure 2 As shown, it includes: an insulation detection subunit, the insulation detection subunit includes: a high-voltage circuit board, a low-voltage circuit board, a low-voltage generator, a high-voltage generator, a first switching switch, a second switching switch, a voltage monitoring circuit, a first single-chip microcomputer, a resistance acquisition submodule, a first input switching array, and a first output switching array;

[0060] The input end of the first input switching array and the output end of the first output switching array are respectively connected to the cables in the cage, the output end of the first input switching array is connected to the input end of the resistance acquisition submodule, the output end of the resistance acquisition submodule is connected to the first input end of the first single-chip microcomputer, the second input end of the first single-chip microcomputer is connected to the output end of the voltage monitoring circuit, the output end of the first single-chip microcomputer is respectively connected to the input end of the high-voltage circuit board and the input end of the low-voltage circuit board, the output end of the high-voltage circuit board is connected to the input end of the high-voltage generator, the output end of the low-voltage circuit board is connected to the input end of the low-voltage generator, the output end of the high-voltage generator and the output end of the low-voltage generator are respectively connected to the input end of the first switching switch, the output end of the first switching switch is connected to the input end of the second switching switch, the output end of the second switching switch is connected to the input end of the first output switching array, the output end of the high-voltage generator is connected to the first input of the voltage monitoring circuit, the output end of the first switching switch is connected to the second input end of the voltage monitoring circuit, and the output end of the second switching switch is connected to the third input end of the voltage monitoring circuit.

[0061] In this embodiment, the insulation test is a test to check the dielectric strength of the insulating material or the insulating structure of the electrical equipment, the purpose of which is to check the safe operation of the product and equipment and prevent short circuits and subsequent dangerous accidents. The insulation test in this embodiment is to detect the resistance value of any cable to be tested and all other cables (including the ground wire) at a specified voltage (the railway standard voltage index is 500V, and the system design voltage is 550V). When the resistance value is greater than 5M ohms, it is qualified. Among them, the cable to be tested refers to the cable connecting the control cabinet and the AC locomotive low-voltage electrical cabinet, and its function is to communicate the electrical connection between the control cabinet and the electrical cabinet to be tested (i.e., the AC locomotive low-voltage electrical cabinet).

[0062] Insulation detection principle block diagram Figure 2As shown, after the industrial computer issues an insulation detection instruction, the first single-chip microcomputer in the insulation and line sequence detection unit, namely MCU (MCU, Microcontroller Unit, also known as single-chip microcomputer), model STC8A8K64SA12, monitors whether the voltage at point T1 of the high-voltage generator meets the requirements. After the requirements are met, the first switching switch is turned on, and the functions of the first switching switch and the second switching switch are monitored through the voltage monitoring points T2 and T3 to prevent accidental output of high voltage from damaging devices that are not resistant to high voltage. Figure 2 There are two diodes between the low voltage generator, the high voltage generator and the first switch, and the diodes have the function of protecting the circuit. The industrial computer sends a test command with a high voltage output line number, and the first single chip controls the first output switch array to output high voltage to the corresponding line number (line 1, line 2, ... line N) through the output interface, and the high voltage on line 1, line 2, ... line N is then sent to the first input switch array through the input interface. The voltage monitoring circuit detects the induced voltage of all line numbers (line 1, line 2, ... line N) to the output high voltage line number, and then the insulation resistance between the two lines can be calculated by Ohm's law.

[0063] Insulation detection uses a specified voltage output to a certain line under test, and the acquisition part samples the voltage of all lines (voltage monitoring circuit). Based on the obtained sampled voltage, known source voltage and sampling resistance, the resistance between lines and between lines and ground can be obtained by calculation.

[0064] The following example illustrates the calculation method of resistance. A person skilled in the art can easily obtain the calculation method of resistance through the above-mentioned induced voltage. Assuming that high voltage is output on line 1, the insulation resistance between line 1 and line 2 is R12, the insulation resistance between line 1 and line 3 is R13, the insulation resistance between line 1 and line N is R1N, the protection resistor is RL, and the sampling resistor in the voltage detection circuit is RC, then the relationship between the sampling voltage VC (i.e., the induced voltage detected in the voltage monitoring circuit) and the high voltage VH and the resistance is as follows:

[0065] VC2 / VH=RC / (R12+RL+RC);

[0066] VC3 / VH=RC / (R13+RL+RC);

[0067] VCN / VH=RC / (R1N+RL+RC);

[0068] Since VH, RL, and RC are all known quantities and VC is the collected value, R12, R13, and R1N can be inferred in reverse order to obtain the insulation resistance value of each line to line 1.

[0069] The insulation and line sequence detection unit further comprises: a line sequence detection subunit, the line sequence detection subunit comprises: a switching relay, a protection resistor and a photoelectric coupler;

[0070] One end of the cable to be detected in the cage is connected to the first end of the switching relay, the second end of the switching relay is connected to the first end of the protective resistor, the second end of the protective resistor is connected to the first input end of the photoelectric coupler, the first output end of the photoelectric coupler is connected to the input end of the control unit, the low-voltage circuit board is connected to the first end of the coil of the switching relay, the second end of the coil of the switching relay is grounded, the second input end of the photoelectric coupler is grounded, and the second output end of the photoelectric coupler is grounded.

[0071] exist Figure 2 The low voltage generator is used to generate the low voltage used for line sequence detection. Figure 3 As shown in the schematic diagram of line sequence detection, a group of line sequence cables to be tested, namely line 1 to line N, are selected, and one of the lines to be tested is selected by controlling switch S to input the line sequence voltage pulse signal. The control unit can judge whether the line sequence is correctly connected through the high and low levels output by the optical coupler. In order to shorten the detection time, multiple detection units will be tested at the same time, and the output can only be output by one line at a time.

[0072] Working principle of the insulation and line sequence detection unit: The insulation and line sequence detection unit is designed with a first single-chip microcomputer, the single-chip microcomputer model is STC8A8K64SA12, the first single-chip microcomputer is connected to the control unit through the RS485 communication protocol, and the first single-chip microcomputer communicates with the control unit. When it is necessary to test the "line insulation" and "line-to-ground insulation" of the low-voltage electrical cabinet, the industrial computer sends an insulation test command with a high-voltage output line number, and the control unit controls the first output switching array to output high voltage to the corresponding line number (line 1, line 2, ... line N) through the output interface, and the high voltage on line 1, line 2, ... line N is then sent to the input switching array through the first input interface, and the voltage monitoring circuit collects the induced voltage of all line numbers (line 1, line 2, ... line N) to the output high-voltage line number, and then the insulation resistance between the two lines can be calculated by Ohm's law.

[0073] When the "line sequence" of the low-voltage electrical cabinet needs to be tested, after the industrial computer issues a line sequence detection command, the first single-chip microcomputer in the insulation and line sequence detection unit controls the low-voltage circuit board to generate the low voltage used for line sequence detection. Select a group of line sequence cables 1 to N to be tested, select one of the tested cables through the control switch S to input the line sequence voltage pulse signal, and the control unit can determine whether the line sequence is correctly connected through the high and low levels output by the optical coupler.

[0074] The resistor and action detection unit includes: an action voltage board, a third switch, a fourth switch, a voltage detection board, a second single chip microcomputer, a milliohm detection subunit, a second output switch array, a second input switch array and a fifth switch;

[0075] The first output end of the action voltage board is connected to the first input end of the third switch, the second output end of the action voltage board is connected to the second input end of the third switch, the output end of the third switch is respectively connected to the input end of the fourth switch and the first end of the voltage detection board, the output end of the fourth switch is respectively connected to the second end of the voltage detection board and the first end of the second output switching array, the third end of the voltage detection board is connected to the first end of the second single-chip microcomputer, the second end of the second single-chip microcomputer is connected to the first end of the milliohm detection subunit, the second end of the milliohm detection subunit is connected to the second end of the second output switching array, the third end of the second single-chip microcomputer is connected to the third end of the second output switching array, the fourth end of the second single-chip microcomputer is connected to the first end of the second input switching array, the fourth end of the second output switching array is connected to the first end of the fifth switch, the second end of the fifth switch is connected to the third end of the second input switching array, the third end of the fifth switch is connected to the relay access cable in the low-voltage electrical cabinet, and the second single-chip microcomputer communicates with the control unit.

[0076] In this embodiment, the relay contact resistance and action detection principle are as follows: Figure 4 As shown, by giving a specified measurement voltage value (i.e., contact resistance measurement voltage) or driving voltage value (i.e., relay action driving voltage), a two-stage switching (i.e., a third switching switch and a fourth switching switch) switch (in this embodiment, the two-stage switching switch is an electronic switch) is used to turn on the corresponding circuit, so that the relay / contactor is turned on to form a routing path, and then the two ends of the route are respectively connected to the measurement terminals of the milliohm detection subunit, and the resistance value of the route is obtained by the milliohm meter detection subunit. In this embodiment, the milliohm detection subunit is implemented using a milliohm meter.

[0077] Relay contact resistance detection working process: when it is necessary to test the "relay contact resistance" of the low-voltage electrical cabinet, after the industrial computer issues a relay contact resistance detection instruction, the second single-chip microcomputer (single-chip microcomputer model is STC8A8K64SA12) in the relay contact resistance and action detection unit (23) controls the action voltage board to give a specified measurement voltage value and drive voltage value, and uses a two-stage switching switch to turn on the corresponding circuit, so that the relay / contactor is turned on to form a routing path, and then the two ends of the routing are respectively connected to the measurement terminals of the milliohm meter to obtain the resistance value of the routing.

[0078] Relay action detection working process: Relay action detection is to detect whether the relay can achieve complete closure and release under the specified driving voltage. By inputting the specified voltage to the relay driving end and measuring the contact resistance between the relay contacts, it can be determined whether the relay meets the requirements. The principle of relay action detection is the same as that of contact resistance. The difference lies in the different voltages given to the relay. The relay contact resistance test input is the rated driving voltage of the relay, and the relay action detection input is the minimum driving voltage of the relay.

[0079] The energy consumption meter detection unit comprises: a switchboard, a transformer coupling circuit and an energy consumption meter;

[0080] The output end of the switchboard is connected to the input end of the transformer coupling, and the output end of the transformer coupling is connected to the input end of the energy consumption meter;

[0081] The switchboard is used to output a preset voltage and current;

[0082] The transformer coupling circuit is used to input the voltage and current of the simulated load into the energy consumption meter;

[0083] The energy consumption meter is used to display the corresponding energy consumption value based on the voltage and current of the simulated load.

[0084] The switchboard comprises: an AC power supply, a sixth switch and a voltage and current output submodule;

[0085] The output end of the AC power supply is connected to the first end of the sixth switch, the second end of the sixth switch is connected to the input end of the transformer coupling circuit, and the third end of the sixth switch is connected to the input end of the voltage and current output submodule;

[0086] The AC power supply is used to provide a preset voltage and current;

[0087] The voltage and current output submodule is used to display preset voltage and current values.

[0088] The transformer coupling circuit comprises: a voltage transformer, a current transformer and a simulated load;

[0089] The second end of the sixth switching switch is respectively connected to the input end of the voltage transformer and the input end of the current transformer, the output end of the voltage transformer is connected to the first input end of the energy consumption meter, the output end of the current transformer is connected to the second input end of the energy consumption meter, and the simulated load is connected in series to the input end of the current transformer.

[0090] In this embodiment, during energy consumption detection, a voltage and current signal is simulated and input into the energy consumption meter, and the indication of the energy consumption meter is manually observed to determine whether it is reasonable, thereby judging the energy consumption function. This embodiment is for the TQA2-AC-7 electronic single-phase watt-hour meter commonly used in AC locomotives. The input voltage signal is 0-187.5V at 50Hz, the transformation ratio is 25000:150, and the input current signal is 0-1.2A at 50Hz, the transformation ratio is 250:1. The voltage and current signals are input through a voltage transformer and a current transformer. The detection principle of the energy consumption meter is as follows: Figure 5 As shown, 50Hz voltage and current signals are artificially simulated and input into the energy consumption meter through voltage transformer and current transformer. The power consumption value of the energy consumption meter is calculated according to the given voltage, current and transformation ratio. The power consumption value of the energy consumption meter is compared with the actual display value of the energy consumption meter to detect the actual function of the energy consumption meter.

[0091] Energy consumption meter detection working process: When it is necessary to test the "energy consumption meter function" of the low-voltage electrical cabinet, after the industrial computer issues an energy consumption meter detection command, the energy consumption meter detection unit controls the switchboard to give a voltage value and a current value, and then transmits the voltage to the switchboard through the transformer coupling circuit (see Figure 5 The power consumption value of the energy consumption meter is calculated according to the given voltage, current and transformation ratio, and the power consumption value is displayed through the voltage and current output submodule. The power consumption value is compared with the actual display value of the energy consumption meter to detect the actual energy consumption of the energy consumption meter.

[0092] The withstand voltage test unit includes: a third single chip microcomputer, a withstand voltage test control board, a withstand voltage generator, a seventh switch, an eighth switch and a voltage monitoring circuit;

[0093] The input end of the withstand voltage test control board is connected to the control end of the third single-chip microcomputer, the output end of the withstand voltage test control board is connected to the input end of the withstand voltage generator, the output end of the withstand voltage generator is connected to the first end of the seventh switch, the second end of the seventh switch is respectively connected to the first end of the voltage monitoring circuit and the first end of the eighth switch, the second end of the eighth switch is respectively connected to the second end of the voltage monitoring circuit and the cable to be detected in the cage, the cable to be detected in the cage is connected to the test end of the withstand voltage test control board, and the third single-chip microcomputer communicates with the control unit.

[0094] In this embodiment, the withstand voltage test is to give the device a voltage higher than its rated voltage and maintain it for a certain period of time to determine whether the insulation material and space distance of the device meet the requirements. In this embodiment, the withstand voltage test is specifically the maximum leakage current of all lead wires (also understood as cables in the cage) in the AC locomotive low-voltage electrical cabinet to the outer casing under a voltage that lasts for a certain period of time. If the leakage current exceeds the standard, it is unqualified. The withstand voltage test principle diagram is shown in the figure below. Figure 6As shown, during the withstand voltage test, it is necessary to ensure that the cabinet is reliably grounded, and the cable to be tested (which can be understood as a cable to be tested in the cage, or a cable among all the lead-out wires) must be connected to the withstand voltage test interface. The industrial computer sends an instruction, the third single-chip microcomputer receives the instruction sent by the control computer, and controls the withstand voltage test control board so that the withstand voltage generator sends the required voltage and detects the voltage. After the voltage detection feedback is confirmed to be correct, the seventh switch and the eighth switch output the voltage to the circuit under test. At this time, the third single-chip microcomputer monitors the leakage current in the circuit in real time. If the leakage current exceeds the standard, the voltage output withstand voltage generator is immediately turned off, so that the withstand voltage generator no longer outputs voltage, and reports the leakage current value and the abnormal detection state; if the leakage current does not exceed the standard, the detection continues until the end of the preset detection cycle, and the maximum leakage current in the detection cycle and the normal detection state are reported.

[0095] The working process of the withstand voltage test: when it is necessary to test the "withstand voltage function" of the low-voltage electrical cabinet cable, after the industrial computer issues a withstand voltage detection command, the third single-chip microcomputer receives the command sent by the control computer, and controls the withstand voltage board to issue the required voltage and detect the voltage. At this time, the third single-chip microcomputer monitors the leakage current in the loop in real time. If the leakage current exceeds the standard, the voltage output is immediately shut down and the leakage current value and the abnormal detection status are reported; if the leakage current does not exceed the standard, the detection continues until the preset detection cycle ends, and the maximum leakage current within the detection cycle and the normal detection status are reported.

[0096] Through the above description of the principle and hardware structure of the automatic detection system of the low-voltage electrical cabinet, it is easy for those skilled in the art to write a program through software language so that the automatic detection system of the low-voltage electrical cabinet can realize various automatic detection functions. This embodiment only illustrates one implementation method:

[0097] The application software of this embodiment is developed in Java as the basic language and adopts the B / S application program of J2EE architecture. The application software mainly includes seven modules: line sequence detection, contact resistance detection, relay action detection, insulation detection, withstand voltage detection, energy consumption meter detection and system setting. Figure 7 As shown. Each detection function is an independent module, and the test sequence is: line sequence detection > relay action detection > contact resistance detection > insulation detection > withstand voltage detection > energy consumption meter detection. And set up three modules including user management, authority management and parameter setting. Among them, user management is responsible for the entry of tester information. Authority management is responsible for the allocation of administrator authority. The administrator has the functions of data deletion and parameter setting more than the operator. The parameter setting module mainly has the adjustment and setting of the test voltage, alarm threshold and reserved interface of the automatic detection device of the low-voltage electrical control cabinet of the AC locomotive.

[0098] The working process of the automatic detection system of the AC locomotive low-voltage electrical control cabinet is as follows:

[0099] Step S1: Connect the wires according to the actual detection sequence;

[0100] Step S2: Start the automatic detection program of the AC locomotive low-voltage electrical control cabinet and select a tester in the interactive interface;

[0101] Step S3: Enter the home page, where six detection modules are displayed side by side. First, select line sequence detection;

[0102] If you select other functions, the software will pop up an alarm box and you must go through the line sequence detection before you can perform other operations;

[0103] Step S4: Enter the number of the low-voltage control cabinet to be tested in the online sequence detection function. If manual testing is selected first, you will not be able to wait until the manual test is completed before selecting automatic testing. After the test is completed, a pop-up prompt will be displayed to indicate the test result. After confirming that the test is completed, it will automatically return to the main interface.

[0104] Step S5: The remaining detection functions are performed in sequence. When all function detections are completed, a pop-up window prompts that the detection is completed and a report is automatically generated and stored in the system.

[0105] You can view it through the history record in the upper right corner of the system. There is a "System Settings" selection button in the upper right corner of the program. After clicking it, there are three interfaces: user management, permission management and parameter configuration.

[0106] Select User Management to add and delete users.

[0107] Permission management allows users to choose whether to grant administrator permissions.

[0108] The parameter configuration can adjust the remaining ports, withstand voltage test voltage, withstand voltage test result alarm threshold, contact resistance test result alarm threshold, insulation test result alarm threshold and energy consumption test result alarm threshold, such as Figure 8 , Fig. 9 , Fig.10 , Fig.11 shown.

[0109] It should be noted that the test object in this embodiment (i.e., the AC locomotive low-voltage electrical cabinet) has some external connectors, and most of the other interfaces that need to be tested are located on the wiring row inside the electrical cabinet, without external connectors. Since the AC locomotive low-voltage electrical cabinet has many wiring connections, repeated connections are more complicated work, so the cables in the cage should be designed as much as possible to be connected once on the AC locomotive low-voltage electrical cabinet.

[0110] The present embodiment proposes an automatic detection system for a low-voltage electrical cabinet, comprising: an industrial computer, a control cabinet, the control unit, the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit are in the control cabinet, the industrial computer is used to send detection instructions to the control unit; the control unit is used to send detection instructions to the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit, so that each unit realizes the corresponding detection function. The system of the present embodiment can automatically perform various detections on thousands of lines in the low-voltage electrical cabinet, solving the problems of information lag, over-reliance on personnel experience, lack of automated testing equipment, and insufficient accumulation of test data in the current detection and maintenance of low-voltage electrical cabinets for AC locomotives. The system reduces the maintenance cycle of low-voltage electrical cabinets, reduces the probability of human errors, and improves the level of detection automation and reliability.

[0111] The various embodiments in the present disclosure are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0112] The protection scope of the present disclosure is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the scope and spirit of the present disclosure. If these changes and modifications fall within the scope of the claims of the present disclosure and their equivalents, the intention of the present disclosure also includes these changes and modifications.

Claims

1. An automatic detection system for a low-voltage electrical cabinet, characterized in that: include: Industrial computer, control unit, insulation and line sequence detection unit, resistance and motion detection unit, energy consumption meter detection unit and withstand voltage test unit; The industrial computer is connected to the control unit and is used to send a detection instruction to the control unit; The control unit is connected to the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit, respectively, and is used to send detection instructions to the insulation and line sequence detection unit, the resistance and motion detection unit, the energy consumption meter detection unit and the withstand voltage test unit; The insulation and line sequence detection unit is connected to the cables in the multiple cages and is used to perform insulation and line sequence detection on the cables in the multiple cages; The resistance and action detection unit is connected to the contact resistance of the relay in the low-voltage electrical cabinet and is used to detect the contact resistance value of the relay in the low-voltage electrical cabinet and whether the relay action meets the requirements; The energy consumption meter detection unit is connected to the load and is used to detect the actual power consumption of the load; The withstand voltage test unit is connected to the cables in the multiple cages and is used to perform withstand voltage test on the cables in the multiple cages.

2. The automatic detection system for low-voltage electrical cabinet according to claim 1 is characterized in that: The cage is provided with cables with the same function and / or wiring mode as those in the low-voltage electrical cabinet.

3. The automatic detection system for low-voltage electrical cabinet according to claim 1 is characterized in that: The insulation and line sequence detection unit includes: an insulation detection subunit, and the insulation detection subunit includes: a high-voltage circuit board, a low-voltage circuit board, a low-voltage generator, a high-voltage generator, a first switch, a second switch, a voltage monitoring circuit, a first single-chip microcomputer, a resistance acquisition submodule, a first input switching array, and a first output switching array; The input end of the first input switching array and the output end of the first output switching array are respectively connected to the cables in the cage, the output end of the first input switching array is connected to the input end of the resistance acquisition submodule, the output end of the resistance acquisition submodule is connected to the first input end of the first single-chip microcomputer, the second input end of the first single-chip microcomputer is connected to the output end of the voltage monitoring circuit, the output end of the first single-chip microcomputer is respectively connected to the input end of the high-voltage circuit board and the input end of the low-voltage circuit board, the output end of the high-voltage circuit board is connected to the input end of the high-voltage generator, the output end of the low-voltage circuit board is connected to the input end of the low-voltage generator, the output end of the high-voltage generator and the output end of the low-voltage generator are respectively connected to the input end of the first switching switch, the output end of the first switching switch is connected to the input end of the second switching switch, the output end of the second switching switch is connected to the input end of the first output switching array, the output end of the high-voltage generator is connected to the first input of the voltage monitoring circuit, the output end of the first switching switch is connected to the second input end of the voltage monitoring circuit, the output end of the second switching switch is connected to the third input end of the voltage monitoring circuit, and the first single-chip microcomputer communicates with the control unit.

4. The automatic detection system for low-voltage electrical cabinet according to claim 3 is characterized in that: The insulation and line sequence detection unit further comprises: a line sequence detection subunit, the line sequence detection subunit comprises: a switching relay, a protection resistor and a photoelectric coupler; One end of the cable to be detected in the cage is connected to the first end of the switching relay, the second end of the switching relay is connected to the first end of the protective resistor, the second end of the protective resistor is connected to the first input end of the photoelectric coupler, the first output end of the photoelectric coupler is connected to the input end of the control unit, the low-voltage circuit board is connected to the first end of the coil of the switching relay, the second end of the coil of the switching relay is grounded, the second input end of the photoelectric coupler is grounded, and the second output end of the photoelectric coupler is grounded.

5. The automatic detection system for low-voltage electrical cabinet according to claim 1 is characterized in that: The resistor and action detection unit includes: an action voltage board, a third switch, a fourth switch, a voltage detection board, a second single chip microcomputer, a milliohm detection subunit, a second output switch array, a second input switch array and a fifth switch; The first output end of the action voltage board is connected to the first input end of the third switch, the second output end of the action voltage board is connected to the second input end of the third switch, the output end of the third switch is respectively connected to the input end of the fourth switch and the first end of the voltage detection board, the output end of the fourth switch is respectively connected to the second end of the voltage detection board and the first end of the second output switching array, the third end of the voltage detection board is connected to the first end of the second single-chip microcomputer, the second end of the second single-chip microcomputer is connected to the first end of the milliohm detection subunit, the second end of the milliohm detection subunit is connected to the second end of the second output switching array, the third end of the second single-chip microcomputer is connected to the third end of the second output switching array, the fourth end of the second single-chip microcomputer is connected to the first end of the second input switching array, the fourth end of the second output switching array is connected to the first end of the fifth switch, the second end of the fifth switch is connected to the third end of the second input switching array, the third end of the fifth switch is connected to the relay access cable in the low-voltage electrical cabinet, and the second single-chip microcomputer communicates with the control unit.

6. The automatic detection system for low-voltage electrical cabinet according to claim 1 is characterized in that: The energy consumption meter detection unit comprises: a switchboard, a transformer coupling circuit and an energy consumption meter; The output end of the switchboard is connected to the input end of the transformer coupling, and the output end of the transformer coupling is connected to the input end of the energy consumption meter; The switchboard is used to output a preset voltage and current; The transformer coupling circuit is used to input the voltage and current of the simulated load into the energy consumption meter; The energy consumption meter is used to display the corresponding energy consumption value based on the voltage and current of the simulated load.

7. The automatic detection system for low-voltage electrical cabinet according to claim 6, characterized in that: The switchboard comprises: an AC power supply, a sixth switch and a voltage and current output submodule; The output end of the AC power supply is connected to the first end of the sixth switch, the second end of the sixth switch is connected to the input end of the transformer coupling circuit, and the third end of the sixth switch is connected to the input end of the voltage and current output submodule.

8. The automatic detection system for low-voltage electrical cabinet according to claim 7, characterized in that: The transformer coupling circuit comprises: a voltage transformer, a current transformer and a simulated load; The second end of the sixth switching switch is respectively connected to the input end of the voltage transformer and the input end of the current transformer, the output end of the voltage transformer is connected to the first input end of the energy consumption meter, the output end of the current transformer is connected to the second input end of the energy consumption meter, and the simulated load is connected in series to the input end of the current transformer.

9. The automatic detection system for low-voltage electrical cabinet according to claim 1, characterized in that: The withstand voltage test unit includes: a third single chip microcomputer, a withstand voltage test control board, a withstand voltage generator, a seventh switch, an eighth switch and a voltage monitoring circuit; The input end of the withstand voltage test control board is connected to the control end of the third single-chip microcomputer, the output end of the withstand voltage test control board is connected to the input end of the withstand voltage generator, the output end of the withstand voltage generator is connected to the first end of the seventh switch, the second end of the seventh switch is respectively connected to the first end of the voltage monitoring circuit and the first end of the eighth switch, the second end of the eighth switch is respectively connected to the second end of the voltage monitoring circuit and the cable to be detected in the cage, the cable to be detected in the cage is connected to the test end of the withstand voltage test control board, and the third single-chip microcomputer communicates with the control unit.

10. The automatic detection system for low-voltage electrical cabinet according to claim 1, characterized in that: The control unit, insulation and line sequence detection unit, resistance and action detection unit, energy consumption meter detection unit and withstand voltage test unit are all placed in a control cabinet.

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