DC power grid insulation detection device

Abstract

The utility model discloses a DC power grid insulation detection device comprising a power supply module and an operation system electrically connected to the power supply module. The operation system comprises a single-chip microcomputer system, a sampling voltage isolation following module, a balance bridge detection module, a non-balance bridge detection module, a CAN output module, a digital and LED display module and a relay output module, and the sampling voltage isolation following module is electrically connected to the single-chip microcomputer system. The balance bridge detection module is electrically connected to the sampling voltage isolation following module, the non-balance bridge detection module is electrically connected to the balance bridge detection module, and the CAN output module is electrically connected to the single-chip microcomputer system. The utility model relates to the field of DC power grid insulation detection tool design, in particular to a DC power grid insulation detection device.

Description

Technical Field

[0001] The utility model relates to the field of DC power grid insulation detection tool design, in particular to a DC power grid insulation detection device. Background Art

[0002] The DC grid insulation detection device mainly refers to an electronic device used to detect insulation reduction or grounding of the DC system, with branch line selection and alarm functions.

[0003] The conventional way to test the insulation condition of a DC power grid is to operate with a single power supply, measuring the total voltage and the negative terminal voltage. The positive terminal voltage is equal to the total voltage minus the negative terminal voltage. In this way, if the negative terminal voltage is close to zero or the total voltage is close to zero, it is easy to misjudge. Utility Model Content

[0004] The technical problem to be solved by the utility model is that misjudgment is easy to occur.

[0005] In order to solve the above problems, the technical solution adopted by the utility model is as follows: The utility model is a DC power grid insulation detection device, including a power supply module and an operating system, the operating system is electrically connected to the power supply module, the operating system includes a single-chip computer system, a sampling voltage isolation follower module, a balanced bridge detection module, an unbalanced bridge detection module, a CAN output module, a digital and LED display module and a relay output module, the sampling voltage isolation follower module is electrically connected to the single-chip computer system, the balanced bridge detection module is electrically connected to the sampling voltage isolation follower module, the unbalanced bridge detection module is electrically connected to the balanced bridge detection module, the CAN output module is electrically connected to the single-chip computer system, the digital and LED display module is electrically connected to the single-chip computer system, the relay output module is electrically connected to the single-chip computer system, and the power supply module supplies power to the single-chip computer system, the sampling voltage isolation follower module, the balanced bridge detection module, the unbalanced bridge detection module, the CAN output module, the digital and LED display module and the relay output module.

[0006] Furthermore, the unbalanced bridge detection module uses an unbalanced bridge method for data collection.

[0007] Preferably, the digital and LED display modules, A1 and A2 are connected to the DC working power supply, and the digital tube first displays "8.8.8.8.", indicating that the digital tube display is normal, and the two indicator lights flash at the same time, and then the digital tube displays "0L". After the two indicator lights go out at the same time, the device enters the monitoring state, and the digital tube displays the insulation resistance value of the monitored power grid to the ground. When the digital tube displays "OL", it means that the insulation resistance exceeds the detection range. When the system detects a disconnection, the digital tube displays "E---", the two indicator lights flash at the same time, and the two relays operate at the same time.

[0008] Preferably, positive terminal alarm, negative terminal alarm, level 1 alarm, and level 2 alarm are set. The positive terminal alarm corresponds to indicator light 1; the negative terminal alarm corresponds to indicator light 2; level 1 alarm corresponds to K1 relay; and level 2 alarm corresponds to K2 relay. The level of level 1 alarm is higher than that of level 2 alarm (i.e., when the level 1 alarm state is reached, the level 2 alarm state has been reached for sure, and the K1 relay and the K2 relay are simultaneously actuated, and the indicator lights corresponding to the positive and negative terminals are lit).

[0009] The factory setting of the alarm initial value is: Level 1 alarm - 100KΩ (setting value 1); Level 2 alarm - 200KΩ (setting value 2).

[0010] Preferably, long press the "Set" key for 3 seconds to enter the level 1 alarm setting state, and the digital tube displays the currently set level 1 initial alarm value. Subsequently, each time the "Set" key is pressed, the set value increases by 10KΩ, and after reaching 100KΩ, it starts to increase from 10KΩ again. After selecting the set value, press the "Confirm" key to enter the level 2 alarm value setting state. The digital tube displays the currently set level 2 initial alarm value. Subsequently, each time the "Set" key is pressed, the set value increases by 10KΩ, and after reaching 300KΩ, it starts to increase from 100KΩ again. After selecting the set value, press the "Confirm" key and the system re-enters the monitoring state. After the alarm value is set, the system automatically saves the set value in the system's built-in memory (power-off retention).

[0011] The beneficial effects achieved by the utility model using the above structure are as follows:

[0012] 1. This product has a small and beautiful appearance, stable performance and simple structure. It adopts new single-chip microcomputer and display chip technology, and the reading is eye-catching and clear. The control adopts a touch-type membrane switch, and the set value has a power-off retention function. The alarm value of the insulation resistance can be set between 10KΩ and 300KΩ, which is completely suitable for low insulation alarm of the power grid under normal circumstances. This continuous automatic monitoring alarm device is of great significance in preventing electrical fire accidents, ensuring the safe operation of the power grid and realizing automated management.

[0013] 2. In terms of electrical control design, this product uses industrial-grade or even military-grade components and utilizes advanced voltage-stabilized power supply technology. The product can still work normally even when the working power supply voltage deviation reaches ±30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit framework diagram of a DC power grid insulation detection device proposed by the utility model;

[0015] Figure 2 This is a circuit diagram of an unbalanced bridge detection module of a DC power grid insulation detection device proposed by the utility model;

[0016] Figure 3This is a schematic diagram of the appearance of a host of a DC power grid insulation detection device proposed by the utility model;

[0017] Figure 4 This is a circuit diagram of a relay output module of a DC power grid insulation detection device proposed by the utility model;

[0018] Figure 5 A wiring diagram of a DC power grid insulation detection device proposed by the utility model;

[0019] Figure 6 This is a function display diagram of a DC power grid insulation detection device proposed by the utility model.

[0020] Among them, 1. operating system, 2. single-chip microcomputer system, 3. sampling voltage isolation follower module, 4. balanced bridge detection module, 5. unbalanced bridge detection module, 6. CAN output module, 7. digital and LED display module, 8. relay output module. DETAILED DESCRIPTION

[0021] like Figure 1 As shown, the utility model is a DC grid insulation detection device, including a power supply module (not shown in the figure) and an operating system 1, the operating system 1 is electrically connected to the power supply module, the operating system 1 includes a single-chip computer system 2, a sampling voltage isolation follower module 3, a balanced bridge detection module 4, an unbalanced bridge detection module 5, a CAN output module 6, a digital and LED display module 7 and a relay output module 8, the sampling voltage isolation follower module 3 is electrically connected to the single-chip computer system 2, the balanced bridge detection module 4 is electrically connected to the sampling voltage isolation follower module 3, the unbalanced bridge detection module 5 is electrically connected to the balanced bridge detection module 4, the CAN output module 6 is electrically connected to the single-chip computer system 2, the digital and LED display module 7 is electrically connected to the single-chip computer system 2, and the relay output module 8 is electrically connected to the single-chip computer system 2. The power supply module supplies power to the single-chip computer system 2, the sampling voltage isolation follower module 3, the balanced bridge detection module 4, the unbalanced bridge detection module 5, the CAN output module 6, the digital and LED display module 7 and the relay output module 8, and the unbalanced bridge detection module 5 adopts an unbalanced bridge method for collection.

[0022] like Figure 3 As mentioned above, A1 and A2 are connected to the DC working power supply, and the digital tube first displays "8.8.8.8.", indicating that the digital tube display is normal, and the two indicator lights flash at the same time, and then the digital tube displays "0L". After the two indicator lights go out at the same time, the device enters the monitoring state, and the digital tube displays the insulation resistance value of the monitored power grid to the ground. When the digital tube displays "OL", it means that the insulation resistance exceeds the detection range. When the system detects a disconnection, the digital tube displays "E---", the two indicator lights flash at the same time, and the two relays act at the same time.

[0023] Positive alarm, negative alarm, level 1 alarm, and level 2 alarm are set. The positive alarm corresponds to indicator light 1; the negative alarm corresponds to indicator light 2; the level 1 alarm corresponds to the K1 relay; the level 2 alarm corresponds to the K2 relay. The level of the level 1 alarm is higher than the level 2 alarm (that is, when the level 1 alarm state is reached, the level 2 alarm state has been reached, and the K1 relay and the K2 relay are activated at the same time, and the indicators corresponding to the positive and negative ends are lit).

[0024] The factory setting of the alarm initial value is: Level 1 alarm - 100KΩ (setting value 1); Level 2 alarm - 200KΩ (setting value 2).

[0025] Long press the "Set" key for 3 seconds to enter the 1st level alarm setting state, and the digital tube displays the currently set 1st level initial alarm value. Then, each time you press the "Set" key, the set value increases by 10KΩ. After reaching 100KΩ, it starts to increase from 10KΩ again. After selecting the set value, press the "Confirm" key to enter the 2nd level alarm value setting state. The digital tube displays the currently set 2nd level initial alarm value. Then, each time you press the "Set" key, the set value increases by 10KΩ. After reaching 300KΩ, it starts to increase from 100KΩ again. After selecting the set value, press the "Confirm" key and the system re-enters the monitoring state. After the alarm value is set, the system automatically saves the set value in the system's built-in memory (power-off retention).

[0026] like Figure 2 As described above, 110V+, 110V- and / KE are the external connection terminals of the system, R+ and R- are the insulation resistance between the positive and negative busbars to be measured and the ground, R55, R56, R57, and R58 are standard resistors of known resistance for measurement, and ADC_0 and ADC_1 are voltage sampling ports.

[0027] When all electronic switches U14 are disconnected, the positive and negative ground voltages V+ and V- are obtained through ADC_0 and ADC_1.

[0028] (The resistance of R59 and R61 is very large, so the current generated by them can be ignored)

[0029] When PC6 turns on the high level control electronic switch 7 and 8, standard resistors R55 and R56 are added between the positive bus and the ground, and the positive and negative terminal voltages V+′ and V-′ to the ground are obtained through ADC_0 and ADC_1.

[0030]

[0031]

[0032] By solving the above formula, we can get R+ and R-

[0033] Similarly, when PC7 turns on the 5th and 6th pins of the high-level control electronic switch, standard resistors R57 and R58 are added between the positive bus and the ground, and the positive and negative terminal voltages V+′ and V-′ to the ground are obtained through ADC_0 and ADC_1.

[0034]

[0035]

[0036] By solving the above formula, we can get R+ and R-. The existing DC online insulation detection device (CHIR125) on the HXD1 locomotive displays OL when the resistance is greater than 200KΩ. This device can display 0~1MΩ, truly displaying the actual value of online insulation.

[0037] It should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A DC power grid insulation detection device, characterized in that: It includes a power supply module and an operating system, wherein the operating system is electrically connected to the power supply module, and the operating system includes a single-chip computer system, a sampling voltage isolation follower module, a balanced bridge detection module, an unbalanced bridge detection module, a CAN output module, a digital and LED display module, and a relay output module. The sampling voltage isolation follower module is electrically connected to the single-chip computer system, the balanced bridge detection module is electrically connected to the sampling voltage isolation follower module, the unbalanced bridge detection module is electrically connected to the balanced bridge detection module, the CAN output module is electrically connected to the single-chip computer system, the digital and LED display module is electrically connected to the single-chip computer system, and the relay output module is electrically connected to the single-chip computer system. The power supply module supplies power to the single-chip computer system, the sampling voltage isolation follower module, the balanced bridge detection module, the unbalanced bridge detection module, the CAN output module, the digital and LED display module, and the relay output module.

2. A DC grid insulation detection device according to claim 1, characterized in that: The unbalanced bridge detection module uses an unbalanced bridge method for data collection.

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