Direct current system insulation adaptive detection method and insulation detection device

Abstract

The invention discloses a direct current system insulation adaptive detection method and an insulation detection device, and relates to the technical field of insulation detection, and the method comprises the steps: checking and confirming the insulation state of a direct current system before equipment is put into operation; if the DC system insulation is in a good state, the equipment is put into operation, and whether voltage to ground is balanced is judged; if the voltage to ground is balanced, a negative insulation resistor is input, and the voltage change condition is recorded; according to the voltage change condition, the operating principle of the insulation device is analyzed. The temporary insulation monitoring device is designed, the defect of bridge resistance of an original system insulation monitoring device can be automatically made up, insulation faults are accurately tested, the device is compatible with the original system device, parallel operation is supported, the insulation monitoring problem of a newly-added direct-current screen cabinet is effectively solved, the detection sensitivity and the system safety are improved, and the false alarm rate is reduced. Intelligent and automatic monitoring is realized, man-machine interaction is optimized, and the communication capability is enhanced, so that the overall performance of insulation monitoring of the direct current system is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of insulation detection, in particular to a DC system insulation adaptive detection method and an insulation detection device. Background Art

[0002] The problem of the balancing bridge of the existing insulation monitoring device. Based on a comprehensive principle analysis, the possible problems with the existing insulation detection device are: the detection principle is unreasonable, resulting in a dead zone in the detection or posing a threat to the safe operation of the system; the selection of the bridge resistance value is unreasonable, posing a threat to the safe operation of the system.

[0003] Problems with parallel operation of multiple insulation monitoring devices. In order to monitor the parameters of the DC system, the insulation monitoring hosts are all designed with bridge circuits. When multiple machines are operated in parallel, multiple bridges in the DC system operate, which brings the following problems: multiple balanced bridge devices operate in parallel - affecting the insulation sensitivity of the operating equipment and reducing the detection capability; multiple ping-pong bridges or balanced bridges + detection bridge devices operate in parallel - the equipment is affected (fighted) during testing, causing false grounding and affecting the test results; balanced bridge devices and ping-pong bridges or balanced bridges + detection bridge devices operate in parallel - the test sensitivity of the balanced bridge devices decreases, and the ping-pong bridge or balanced bridge + detection bridge devices detect bipolar grounding faults.

[0004] The patent of this invention studies a DC system insulation state calculation method for a balance bridge of an adaptive operating insulation detection device. The method solves the problem of operating insulation devices: adaptively calculates insulation faults based on the bridge resistance of the original DC system insulation device; when there are defects in the bridge resistance of the original system insulation monitoring device, the defects are automatically compensated to accurately test the insulation fault. A temporary insulation monitoring device is designed based on the method. The temporary insulation monitoring device designed by this method is compatible with the original system insulation monitoring device, and two devices can be operated in parallel to solve the insulation state monitoring problem of the newly added DC panel cabinet. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is: how to solve the problem that the existing detection principle is unreasonable, resulting in dead zones in detection or posing a threat to the safe operation of the system; the selection of bridge resistance value is unreasonable, posing a threat to the safe operation of the system; the problem of multiple balanced bridge devices running in parallel, multiple ping-pong bridges or balanced bridges + detection bridge devices running in parallel, and the problem of balanced bridge devices and ping-pong bridges or balanced bridges + detection bridge devices running in parallel.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a DC system insulation adaptive detection method, comprising: checking and confirming the insulation status of the DC system before the equipment is put into operation; if the insulation of the DC system is in good condition, the equipment is put into operation to determine whether the voltage to the ground is balanced; if the voltage to the ground is balanced, the negative pole insulation resistance is input and the voltage change is recorded; according to the voltage change, the operating principle of the insulation device is analyzed.

[0008] As a preferred solution of the DC system insulation adaptive detection method described in the present invention, the equipment commissioning includes connecting the new equipment to a high input impedance circuit for voltage detection to detect the voltage.

[0009] As a preferred solution of the DC system insulation adaptive detection method described in the present invention, the judgment of whether the voltage to ground is balanced includes rechecking and confirming the insulation state of the DC system if the voltage to ground is unbalanced; if the voltage to ground is balanced, inputting the negative pole insulation resistance and recording the voltage change.

[0010] As a preferred solution of the DC system insulation adaptive detection method described in the present invention, the voltage change condition includes no voltage fluctuation, the presence of a positive pole to ground leakage current U + = 0 phenomenon and fluctuation and no U + =0 situation.

[0011] As a preferred solution of the DC system insulation adaptive detection method described in the present invention, the principle of analyzing the operation of the insulation device includes: if it is a voltage non-fluctuation phenomenon, then according to the balanced bridge principle, evaluating the balanced bridge resistance value, judging the balanced bridge resistance, if the bridge resistance is large, compensating the balanced bridge, and adjusting a suitable detection bridge based on the compensated balanced bridge and the uncompensated balanced bridge, and testing the system insulation based on the compensated balanced bridge and the adjusted detection bridge.

[0012] As a preferred solution of the DC system insulation adaptive detection method described in the present invention, the analysis and operation principle of the insulation device also includes if there is a positive pole to ground leakage current U + =0 phenomenon, then according to the ping-pong bridge principle, evaluate the resistance value of the ping-pong bridge, compensate the balanced bridge, use the ping-pong bridge as a detection bridge, and test the insulation of the system based on the compensated balanced bridge and the ping-pong bridge.

[0013] As a preferred solution of the DC system insulation adaptive detection method of the present invention, wherein: the analysis and operation insulation device principle also includes if there is fluctuation and no U + =0, the principle of balancing bridge plus detection bridge is used to evaluate and calculate the resistance values ​​of the balancing bridge and the detection bridge, and the insulation status is directly detected with the help of the bridge circuit with the original resistance value.

[0014] Another object of the present invention is to provide a device for a DC system insulation adaptive detection method, which can solve a DC system insulation adaptive detection problem by constructing an adaptive insulation monitoring device.

[0015] In order to solve the above technical problems, the present invention provides the following technical solutions: a DC system insulation adaptive detection device, comprising a power supply circuit, a control CPU circuit, a display unit, a voltage measurement circuit, a communication circuit, a bridge resistance compensation circuit and an alarm circuit; the power supply circuit is used to supply the entire device; the control CPU circuit is used to complete data calculation, display processing, and communication processing functions; the display unit is used to complete the human-computer interaction function; the voltage measurement circuit is used to complete the DC system voltage data acquisition function; the communication circuit is a functional circuit for communicating with equipment components and a host computer; the bridge resistance compensation circuit is used to design a multi-channel resistor and a control input circuit, and the input resistor can change the system bridge resistance; the alarm circuit is used to output an alarm signal; the signal source power supply adopts a multi-channel output switching power supply design, outputs 12V and 5V, and the power supply chip ASM1117 is designed to achieve a stable 3.3V output.

[0016] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned DC system insulation adaptive detection method when executing the computer program.

[0017] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above-mentioned DC system insulation adaptive detection method.

[0018] The beneficial effects of the present invention are as follows: a temporary insulation monitoring device designed by a DC system insulation adaptive detection method provided by the present invention can automatically compensate for the defects of the bridge resistance of the original system insulation monitoring device, accurately test insulation faults, and is compatible with the original system device, supporting parallel operation, effectively solving the insulation monitoring problem of newly added DC panel cabinets, improving detection sensitivity and system safety, reducing false alarm rate, realizing intelligent and automated monitoring, optimizing human-computer interaction, and enhancing communication capabilities, thereby significantly improving the overall performance of DC system insulation monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0020] Figure 1A flow chart of a DC system insulation adaptive detection method provided by the first embodiment of the present invention.

[0021] Figure 2 A flow chart of an adaptive original insulation device balancing bridge algorithm of a DC system insulation adaptive detection method provided in the first embodiment of the present invention.

[0022] Figure 3 This is a diagram showing the architecture of an adaptive insulation monitoring device for a DC system insulation adaptive detection device provided in accordance with a second embodiment of the present invention.

[0023] Figure 4 A 3.3V power supply circuit diagram of a DC system insulation adaptive detection device provided in the second embodiment of the present invention.

[0024] Figure 5 A main control CPU and peripheral minimum circuit diagram of a DC system insulation adaptive detection device provided in the second embodiment of the present invention.

[0025] Figure 6 A high input impedance circuit diagram of a DC system insulation adaptive detection device provided in the second embodiment of the present invention.

[0026] Figure 7 An operational amplifier diagram of a DC system insulation adaptive detection device provided by the second embodiment of the present invention.

[0027] Figure 8 A signal amplifying circuit diagram of a DC system insulation adaptive detection device provided in the second embodiment of the present invention.

[0028] Fig. 9 A current signal acquisition circuit diagram of a DC system insulation adaptive detection device provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Example 1, reference Figure 1 and Figure 2, which is the first embodiment of the present invention, provides a DC system insulation adaptive detection method, including: checking and confirming the DC system insulation status before the equipment is put into operation; if the DC system insulation is in good condition, the equipment is put into operation to determine whether the voltage to the ground is balanced; if the voltage to the ground is balanced, the negative pole insulation resistance is input and the voltage change is recorded; according to the voltage change, the operating principle of the insulation device is analyzed.

[0032] like Figure 2 As shown in the figure, before the adaptive insulation monitoring device is put into operation, it is necessary to ensure that the insulation state of the DC system is in good condition; at the initial stage of the equipment operation, only the voltage acquisition circuit is put into operation (the voltage acquisition circuit is designed with high impedance input), which does not affect the resistance of the system balance bridge; the voltage acquisition circuit is used to collect the voltage of the DC system to the ground, and the collected voltage result is used to judge whether the DC system is really in a good insulation state. If there is still a deviation in the voltage, it is prompted to manually check and eliminate the insulation fault. If the insulation is good, proceed to the next step; a 50kΩ resistor is put between the negative pole and the ground to simulate the insulation drop of the DC system, and the monitoring is carried out for 100s. The voltage changes inside the insulation device are recorded, and the voltage value of each change state is recorded. The insulation device principle of the original system is analyzed through the recorded voltage change state values. When the balanced bridge principle is used, the resistance of the balanced bridge needs to be evaluated. When the resistance is too large, the balanced bridge needs to be compensated, and a detection bridge is added to realize the balanced bridge + detection bridge technology to detect the insulation state. When the ping-pong bridge principle is used, the resistance of the ping-pong bridge needs to be evaluated, the balanced bridge needs to be compensated, and the ping-pong bridge can be used as a detection bridge. In this way, the balanced bridge + detection bridge technology can be used to detect the insulation state. When the balanced bridge + detection bridge principle is used, the resistance values ​​of the balanced bridge and the detection bridge are evaluated and calculated, and the insulation state is directly detected with the help of the bridge circuit with the original resistance value.

[0033] S1. Check and confirm the insulation status of the DC system before putting the equipment into operation.

[0034] S2. If the insulation of the DC system is in good condition, the equipment is put into operation to determine whether the voltage to ground is balanced.

[0035] The new device only detects voltage by connecting to the high input impedance circuit of the voltage detection.

[0036] Determine whether the voltage to ground is balanced. If the voltage to ground is unbalanced, recheck and confirm the insulation status of the DC system; if the voltage to ground is balanced, test the negative pole insulation resistance and record the voltage change.

[0037] S3. If the voltage to ground is balanced, then the negative electrode insulation resistance is input and the voltage change is recorded.

[0038] Voltage changes include no voltage fluctuation and the presence of a positive-to-ground leakage current U + = 0 phenomenon and fluctuation and no U + =0 situation.

[0039] S4. Analyze the operating principle of the insulation device based on voltage changes.

[0040] If the voltage does not fluctuate, evaluate the resistance value of the balanced bridge according to the balanced bridge principle and judge the balanced bridge resistance. If the bridge resistance is large, compensate the balanced bridge. Adjust the appropriate detection bridge based on the compensated balanced bridge and the uncompensated balanced bridge. Test the insulation of the system based on the compensated balanced bridge and the adjusted detection bridge.

[0041] If there is a leakage current U from the positive electrode to the ground + =0 phenomenon, then according to the ping-pong bridge principle, evaluate the resistance value of the ping-pong bridge, compensate the balanced bridge, use the ping-pong bridge as a detection bridge, and test the insulation of the system based on the compensated balanced bridge and the ping-pong bridge.

[0042] If it is a fluctuation and there is no U + =0, the principle of balancing bridge plus detection bridge is used to evaluate and calculate the resistance values ​​of the balancing bridge and the detection bridge, and the insulation status is directly detected with the help of the bridge circuit with the original resistance value.

[0043] Example 2, reference Figure 3 to Figure 9 , which is the second embodiment of the present invention, which is different from the previous embodiment in that it provides a DC system insulation adaptive detection device, including: a power supply circuit 100, a control CPU 200, a display unit 300, a voltage measurement circuit 400, a communication circuit 500, a bridge resistance compensation circuit 600 and an alarm circuit 700;

[0044] The power supply circuit 100 is used to supply the entire device; the control CPU circuit 200 is used to complete data calculation, display processing, communication processing and other functions; the display unit 300 is used to complete the human-computer interaction function; the voltage measurement circuit 400 is used to complete the DC system voltage data acquisition function; the communication circuit 500 is used to communicate with the equipment components, the host computer and other functional circuits; the bridge resistance compensation circuit 600 is used to design multi-channel resistance and control input circuit, and the input resistance can change the system bridge resistance; the alarm circuit 700 is used to output the alarm signal. Figure 3 shown.

[0045] The signal source power supply adopts a multi-channel output switching power supply design, outputs 12V and 5V, and designs the power chip ASM1117 to achieve a stable 3.3V output. Figure 4 shown.

[0046] The main control CPU uses STM32F103ZET6. This chip is an ARM 32-bit Cortex TM --M3 CPU, with the characteristics of fast running speed, large storage capacity, low power consumption and a large number of various functional interfaces. Control CPU200 such as Figure 5 shown.

[0047] The display unit is designed with a 7-inch industrial touch screen.

[0048] The voltage measurement circuit 400 is designed as Figure 6 As shown in the figure, the voltage sampling circuit is designed with 4 resistors, and the total resistance of the resistors exceeds 1MΩ, which does not affect the bridge resistance loop of tens of kilo-ohms. After the input voltage is divided by the resistors, an optical coupler is designed to isolate and amplify the high voltage, and then differential amplification is performed through the operational amplifier, and finally data acquisition is performed. The circuit is as follows Figure 7 and Figure 8 shown.

[0049] The communication circuit 500 is designed, and a 485 communication level chip is used to design a 3-way serial port communication circuit to meet the communication needs of the device and related equipment.

[0050] The bridge resistance compensation circuit 600 is designed as Fig. 9 As shown, a relay drive circuit is designed with a triode, and the power resistor is switched by controlling the on and off of the relay. The capacitor and diode of the relay are designed to eliminate the interference of the jitter to prevent the relay from erroneously switching the resistor to change the bridge resistance value of the system. Multiple similar resistor control circuits are designed between the positive and negative grounds to achieve the requirements of balanced bridge compensation and bridge input detection. The multiple power resistors include: 15kΩ, 20kΩ, 25kΩ, 30kΩ, 50kΩ, 100kΩ, 150kΩ, and 200kΩ.

[0051] The alarm circuit 700 is designed, and relays and transistors are used to complete the relay control and output circuit design to complete the alarm circuit design.

[0052] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0053] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0054] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0055] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0056] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A DC system insulation adaptive detection method, characterized in that: include, Check and confirm the insulation status of the DC system before the equipment is put into operation; If the insulation of the DC system is in good condition, the equipment is put into operation to determine whether the voltage to ground is balanced; If the voltage to ground is balanced, then the negative electrode insulation resistance is input and the voltage change is recorded; Analyze the operating principle of the insulation device based on the voltage changes.

2. A DC system insulation adaptive detection method according to claim 1, characterized in that: The equipment commissioning includes connecting the new equipment only to a high input impedance circuit for voltage detection to detect voltage.

3. A DC system insulation adaptive detection method as claimed in claim 2, characterized in that: The determining whether the voltage to ground is balanced includes rechecking and confirming the insulation state of the DC system if the voltage to ground is unbalanced; If the voltage to ground is balanced, then the negative electrode insulation resistance is input and the voltage change is recorded.

4. A DC system insulation adaptive detection method as claimed in claim 3, characterized in that: The voltage change conditions include no voltage fluctuation, the presence of a positive pole to ground leakage current U + = 0 phenomenon and fluctuation and no U + =0 situation.

5. A DC system insulation adaptive detection method as claimed in claim 4, characterized in that: The principle of analyzing and operating the insulation device includes: if there is a voltage fluctuation phenomenon, then based on the balanced bridge principle, evaluating the balanced bridge resistance value, judging the balanced bridge resistance, if the bridge resistance is large, compensating the balanced bridge, and adjusting a suitable detection bridge based on the compensated balanced bridge and the uncompensated balanced bridge, and testing the system insulation based on the compensated balanced bridge and the adjusted detection bridge.

6. A DC system insulation adaptive detection method as claimed in claim 5, characterized in that: The analysis and operation of the insulating device principle also includes the following: if there is a positive pole to ground leakage current U + =0 phenomenon, then according to the ping-pong bridge principle, evaluate the resistance value of the ping-pong bridge, compensate the balanced bridge, use the ping-pong bridge as a detection bridge, and test the insulation of the system based on the compensated balanced bridge and the ping-pong bridge.

7. A DC system insulation adaptive detection method according to claim 6, characterized in that: The analysis and operation of the insulation device principle also includes if there is fluctuation and no U + =0, the principle of balancing bridge plus detection bridge is used to evaluate and calculate the resistance values ​​of the balancing bridge and the detection bridge, and the insulation status is directly detected with the help of the bridge circuit with the original resistance value.

8. A device using a DC system insulation adaptive detection method as claimed in any one of claims 1 to 7, characterized in that: It comprises a power supply circuit (100), a control CPU circuit (200), a display unit (300), a voltage measurement circuit (400), a communication circuit (500), a bridge resistance compensation circuit (600) and an alarm circuit (700); The power supply circuit (100) is used to supply power to the entire device; The control CPU circuit (200) is used to complete data calculation, display processing, and communication processing functions; The display unit (300) is used to complete the human-computer interaction function; The voltage measurement circuit (400) is used to complete the DC system voltage data collection function; The communication circuit (500) is a functional circuit used for communicating with device components and a host computer; The bridge resistance compensation circuit (600) is used to design a multi-channel resistance and control input circuit, and can input resistance to change the bridge resistance of the system; The alarm circuit (700) is used to output an alarm signal; The signal source power supply adopts a multi-channel output switching power supply design, outputs 12V and 5V, and designs the power chip ASM1117 to achieve a stable 3.3V output.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a DC system insulation adaptive detection method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a DC system insulation adaptive detection method according to any one of claims 1 to 7 are implemented.

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