A DC power supply monitor with insulation monitoring function

Abstract

This utility model discloses a DC power supply monitor with insulation monitoring function, including a DC power supply system, a monitoring module, an operating host, and an alarm unit. The DC power supply system consists of a DC signal source and multiple branch circuits. The monitoring module includes a resistance balance bridge and a voltage monitoring relay, used to detect the voltage of the positive and negative poles to ground and determine the insulation status. The operating host includes a hardware system, an embedded software system, and a user interface module, realizing data acquisition, analysis, and parameter setting. The alarm unit issues an audible and visual alarm and records alarm information when insulation is abnormal. The monitoring module and the operating host are connected through a communication bus. The operating host in this utility model supports multiple voltage levels and has an automatic identification function, which can adapt to the insulation monitoring needs of different DC power supply systems, improving system operation safety and maintenance efficiency.

Description

Technical Field

[0001] This utility model relates to the field of power system commissioning technology, specifically to a DC power supply monitoring instrument with insulation monitoring function. Background Technology

[0002] In the commissioning of power system relay protection, DC test power supply instruments are used as key power supply equipment in substation renovation, expansion and new equipment commissioning and acceptance. The quality and safety of their power supply directly affect the reliability of relay protection devices and thus the safe operation of the entire substation. In current practical engineering applications, the output terminals of the test power supply panels and existing DC power supply instruments in the substation are generally not equipped with insulation monitoring devices, making it difficult to monitor the insulation status of the secondary circuit in real time during the commissioning process.

[0003] When a grounding fault or a drop in insulation performance occurs in the DC circuit of a newly connected device, the existing equipment cannot perform automatic detection and alarm functions. Operators often find it difficult to detect the hidden danger in time, which can easily lead to serious consequences such as protection malfunction and control circuit failure. Traditional insulation detection methods mainly rely on manual testing with insulation resistance testers periodically or in stages. This method is not only inefficient and dependent on the operator's experience, but also lacks continuity and real-time performance, making it impossible to implement full-process insulation monitoring of the secondary circuit during the entire commissioning process.

[0004] Therefore, it is necessary to provide a DC power supply monitoring device with a reasonable structure, complete functions, and convenient operation, which can monitor the insulation status of the DC test power supply system in real time and has functions such as grounding alarm, insulation abnormality recording, and voltage display. Utility Model Content

[0005] This utility model discloses a DC power supply monitoring instrument with insulation monitoring function, which aims to solve the problems of no insulation monitoring, no monitoring alarm, and no grounding record of DC test power supply during the commissioning and acceptance process in the above-mentioned background art.

[0006] To achieve the above objectives, the technical solution adopted is:

[0007] A DC power supply monitor with insulation monitoring function includes a DC power supply system, a monitoring module, an operating host, and an alarm unit. The DC power supply system is connected to the monitoring module, the monitoring module is connected to the operating host via a communication bus, and the alarm unit is connected to the operating host.

[0008] The DC power supply system mainly consists of a DC signal source and multiple branch circuits. The positive and negative terminals of the DC signal source are connected to the positive bus and the negative bus, respectively. Each branch circuit includes a load element and a distributed capacitor. All load elements are connected to the DC signal source.

[0009] The monitoring module includes a resistance balance bridge monitoring module and a voltage monitoring relay. The resistance balance bridge monitoring module is connected between the positive and negative terminals of the DC power supply system and the ground to provide a reference ground potential and form a ground voltage detection circuit. The voltage monitoring relay is electrically connected to the resistance balance bridge monitoring module and is used to determine the insulation status of the secondary circuit based on the voltage deviation.

[0010] The host computer includes a hardware system, an embedded software system, and a user interface module;

[0011] The alarm unit includes an alarm device and a counter. The alarm device is used to issue an audible and visual alarm signal when an abnormality is detected. The counter records the number of alarms and stores the alarm information.

[0012] The resistance balance bridge monitoring module consists of two high-precision resistors with the same resistance value, forming a symmetrical bridge structure to provide a stable reference ground potential, and detects changes in the positive and negative voltages to ground through a voltage monitoring relay.

[0013] The hardware system includes a voltage acquisition module, a data processing module, and an alarm output module; the embedded software system is used to realize the functions of voltage data acquisition, insulation status analysis, alarm judgment, and alarm count recording.

[0014] The user interface module is used to display voltage values, alarm status, and historical data, and supports parameter setting and data export through a graphical interface.

[0015] Preferably, the alarm device is an audible and visual alarm light connected to the contacts of a voltage monitoring relay. When the voltage between the positive or negative terminal of the DC power supply system and ground deviates from the set range, an alarm is automatically triggered to remind on-site personnel to handle the insulation abnormality in a timely manner.

[0016] Preferably, the host computer supports the access of DC power supply systems with multiple voltage levels, and has a built-in automatic identification module that can detect the input voltage level and set different insulation alarm thresholds according to different voltage levels, so as to realize the monitoring of different test DC power supplies and grounding fault early warning.

[0017] Preferably, the voltage acquisition module uses a differential amplifier circuit to acquire the positive and negative voltage signals of the system under test to ground.

[0018] Preferably, the voltage acquisition module includes an amplifier, which is an operational amplifier and a data amplifier that employs low noise, low drift, low power consumption, and high isolation.

[0019] Preferably, the user interface module uses a touch screen display and supports setting alarm thresholds, sampling frequency, and communication parameters through a graphical interface.

[0020] Preferably, the DC signal source is a DC power supply with a rated voltage of 220V; the monitoring module is set with a ground voltage deviation alarm threshold of 23V; and the communication bus is an RS485 or CAN bus.

[0021] This utility model has the following beneficial effects:

[0022] 1. This utility model discloses a DC power supply monitoring instrument with insulation monitoring function. By adopting a dual detection system composed of a resistance balance bridge monitoring module and a voltage monitoring relay, it can monitor the changes in the positive and negative pole voltages to ground of the DC power supply system in real time, accurately determine the insulation status of the secondary circuit, improve the detection accuracy, and ensure timely detection of insulation abnormalities.

[0023] 2. The hardware circuit system and embedded software system of this utility model's DC power supply monitor with insulation monitoring function work together to achieve intelligent monitoring. The voltage acquisition module adopts a differential amplifier circuit and a high-quality operational amplifier to ensure the accuracy and stability of signal acquisition. The data processing module, in conjunction with the embedded software, can automatically analyze the insulation status and make alarm judgments, improving the reliability of the system. The user interface module adopts a touch screen display, which is simple and intuitive to operate. Operators can easily set various parameters and view real-time monitoring data and historical records through the graphical interface, improving the ease of use and work efficiency of the equipment. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the present utility model;

[0025] Figure 2 This is a circuit diagram of the DC power supply system of this utility model;

[0026] Figure 3 This is a schematic diagram of the resistance balance bridge monitoring module of this utility model;

[0027] Figure 4 This is a structural diagram of the operating host of this utility model;

[0028] Figure 5 This is a connection diagram of the operating host of this utility model.

[0029] Marked in the image:

[0030] 1. DC power supply system; 11. DC signal source; 12. Branch circuit; 2. Monitoring module; 21. Resistance balance bridge monitoring module; 22. Voltage monitoring relay; 3. Operating host; 31. Hardware system; 311. Voltage acquisition module; 312. Data processing module; 313. Alarm output module; 32. Embedded software system; 33. User interface module; 4. Alarm unit; 41. Alarm device; 42. Counter. Detailed Implementation

[0031] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the technical solutions in the specific embodiments of this utility model are clearly and completely described below to further illustrate this utility model. Obviously, the specific embodiments described are only a part of the embodiments of this utility model, and not all of them.

[0032] Example:

[0033] The following is in conjunction with the appendix Figure 1-5 The present invention will be described in further detail below.

[0034] Please see Figure 1-3 This utility model provides a technical solution: a DC power supply monitor with insulation monitoring function, including a DC power supply system 1, a monitoring module 2, an operating host 3, and an alarm unit 4. The DC power supply system 1 is connected to the monitoring module 2, the monitoring module 2 is connected to the operating host 3 through a communication bus, and the alarm unit 4 is connected to the operating host 3.

[0035] The DC power supply system 1 mainly consists of a DC signal source 11 and multiple branch circuits 12. The positive terminal of the DC signal source 11 is connected to the positive bus, and the negative terminal is connected to the negative bus. Each branch circuit 12 includes a load element and a distributed capacitor. The load element is connected in parallel with the DC signal source 11 to form a complete power supply circuit.

[0036] The DC power supply system 1 includes a DC signal source 11 and multiple branch circuits 12. The DC signal source 11 is connected to a positive bus and a negative bus. The branch circuits 12 include loads and distributed capacitance Cd connected to the DC signal source respectively. The DC signal source 11 is a 220V DC voltage source. The DC power supply system 1 also includes a system positive to ground insulation resistance R+ and a system negative to ground insulation resistance R-. The system positive to ground insulation resistance R+ and system negative to ground insulation resistance R- are connected to the positive bus and the negative bus respectively and then grounded.

[0037] Monitoring module 2 includes a resistance balance bridge monitoring module 21 and a voltage monitoring relay 22. The resistance balance bridge monitoring module 21 consists of two high-precision resistors with the same resistance value, forming a bridge symmetrical structure. The bridge circuit is connected between the positive and negative terminals of the DC power supply system and is connected to the ground through the grounding terminal to provide a stable reference ground potential. Through this bridge structure, the changes in the voltage between the positive and negative terminals of the DC system and the ground can be detected, thereby determining the insulation status of the system. The voltage monitoring relay 22 is electrically connected to the resistance balance bridge monitoring module 21 and is used to determine the insulation status of the secondary circuit based on the deviation of the voltage between the positive and negative terminals and the ground. When the voltage between the positive and negative terminals and the ground deviates from the set range, the voltage monitoring relay 22 triggers an alarm signal and sends abnormal information to the operating host 3.

[0038] Based on insulation detection technology, the monitoring module 2 is equipped with a resistance balance bridge monitoring module 21. The balance bridge monitoring module can provide the "ground" potential, enabling the voltage monitoring device to effectively measure the positive and negative power values ​​of the test power supply. The voltage monitoring relay triggers the alarm device and connects it to the counter. When a DC circuit grounding or insulation degradation occurs during construction, it can be detected in time and an alarm can be issued through an audible and visual alarm light to eliminate potential hazards in the secondary circuit and reduce the risk of equipment failure.

[0039] See Figure 4 As shown, the operating host 3 includes a hardware system 31, an embedded software system 32, and a user interface module 33. The operating host 3 has a built-in automatic identification module that can detect the voltage level of the DC power supply and automatically set the corresponding insulation alarm threshold according to the voltage level, making it suitable for DC systems with multiple voltage levels.

[0040] See Figure 5 As shown, in this embodiment, the hardware system 31 includes a voltage acquisition module 311, a data processing module 312, and an alarm output module 313. The voltage acquisition module 311 uses a differential amplifier circuit to acquire the positive and negative voltage signals of the DC power supply system to ground. The amplifiers are selected as low-noise, low-drift, low-power, and high-isolation operational amplifiers and data amplifiers to ensure acquisition accuracy and system stability. The data processing module 312 performs analog-to-digital conversion and data analysis on the received voltage signals to determine the insulation status. The alarm output module 313 is used to control the output of the alarm device 41 to realize the triggering and transmission of the alarm signal.

[0041] The embedded software system 32 collects voltage data in real time, performs insulation status analysis on the collected voltage data, determines whether an insulation abnormality has occurred, records the number of alarms and alarm information, communicates with the alarm unit 4, controls the triggering of the alarm device, and supports automatic identification and parameter configuration of different voltage levels.

[0042] The user interface module 33 uses a touch screen display and supports a graphical operation interface. It can display the current voltage value, alarm status and historical information, and provides a parameter setting interface. It supports users to set alarm thresholds, sampling frequency, communication parameters, etc. It also supports the function of exporting historical data, which is beneficial for subsequent analysis and archiving. The display screen uses the built-in system touch screen technology, and the communication connection uses Modbus protocol serial port technology to improve the stability of the system.

[0043] The alarm unit 4 includes an alarm device 41 and a counter 42. The alarm device 41 is used to issue an audible and visual alarm signal when an abnormality is detected. The alarm device 41 is an audible and visual alarm light connected to the contacts of the voltage monitoring relay 22. When the voltage between the positive or negative terminal of the DC power supply system 1 and ground exceeds a set threshold, the alarm device 41 automatically triggers an audible and visual alarm to remind on-site personnel to handle the grounding fault in a timely manner. The counter 42 records the number of times each alarm is triggered and stores information such as the time, type, and voltage value of the alarm, which is convenient for later maintenance and fault analysis. The counter 42 can store 100 test data points, which can be arranged by date and time for easy data retrieval and supports external export.

[0044] In this embodiment, the DC signal source 11 is a DC power supply with a rated voltage of 220V; the monitoring module 2 sets the ground voltage deviation alarm threshold to 23V; the communication bus adopts RS485 or CAN bus; the voltage acquisition module 311 uses a high-precision operational amplifier, which has good anti-interference performance and measurement accuracy.

[0045] The monitoring module 2 is connected to the operating host 3 via a communication bus, which uses RS485 or CAN bus and has the advantages of strong anti-interference ability, long transmission distance and high communication rate, ensuring stable transmission of monitoring data.

[0046] The technical principle of this invention is as follows: By monitoring the voltage drop across the ground of the resistor connected in parallel to the positive and negative terminals of the power supply system, the insulation condition of the secondary circuit system is determined through the voltage deviation. Simultaneously, a low insulation alarm is triggered, and the alarm count and level are recorded. The invention is connected to test power supply systems of various voltage levels to monitor the grounding condition of the secondary circuit. In use, the voltage input and output lines are connected, the equipment power is turned on, and when the DC power supply system 1 is running normally, the voltages of the positive and negative busbars to ground remain balanced. The equipment automatically enters the monitoring state. The resistance balance bridge monitoring module 21 in the monitoring module 2 collects the voltages of the positive and negative terminals to ground and transmits the voltage signals. The voltage is handed over to the voltage monitoring relay 22, which sends the collected voltage signal to the voltage acquisition module 311 of the operating host 3. After amplification, filtering, and analog-to-digital conversion, the signal is sent to the data processing module 312 for analysis. If the detected voltage deviation exceeds the set threshold, the embedded software system 32 determines that it is an insulation abnormality and triggers the alarm output module 313. The alarm device 41 receives the signal from the alarm output module 313 and starts to issue an audible and visual alarm. The counter 42 records the alarm information at the same time. The user can view the alarm status, set parameters, and export historical data through the user interface module 33. The device power is turned off when the work is finished.

[0047] This invention features an automatic identification function, making it compatible with DC power supply systems of various voltage levels. When connected to DC power supplies of different voltage levels, the built-in automatic identification module detects the input voltage and automatically adjusts the corresponding insulation alarm threshold to ensure the accuracy and reliability of monitoring. During the use of this monitor, all modules work together to achieve real-time monitoring and fault warning of the insulation status of the DC power supply system, effectively ensuring the safe and stable operation of the power system.

[0048] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A DC power supply monitoring instrument with insulation monitoring function, characterized in that, It includes a DC power supply system (1), a monitoring module (2), an operating host (3), and an alarm unit (4). The DC power supply system (1) is connected to the monitoring module (2), the monitoring module (2) is connected to the operating host (3) via a communication bus, and the alarm unit (4) is connected to the operating host (3). The DC power supply system (1) mainly consists of a DC signal source (11) and multiple branch circuits (12). The positive and negative terminals of the DC signal source (11) are connected to the positive bus and the negative bus, respectively. Each branch circuit (12) includes a load element and a distributed capacitor. The load element is connected to the DC signal source (11). The monitoring module (2) includes a resistance balance bridge monitoring module (21) and a voltage monitoring relay (22). The resistance balance bridge monitoring module (21) is connected between the positive and negative terminals of the DC power supply system (1) and the ground, and is used to provide a reference ground potential and form a ground voltage detection circuit. The voltage monitoring relay (22) is electrically connected to the resistance balance bridge monitoring module (21) and is used to determine the insulation status of the secondary circuit based on the voltage deviation. The host computer (3) includes a hardware system (31), an embedded software system (32), and a user interface module (33). The alarm unit (4) includes an alarm device (41) and a counter (42). The alarm device (41) is used to issue an audible and visual alarm signal when an abnormality is detected. The counter (42) records the number of alarms and stores alarm information.

2. A DC power supply monitoring instrument with insulation monitoring function according to claim 1, characterized in that, The resistance balance bridge monitoring module (21) consists of two high-precision resistors with the same resistance value, forming a symmetrical bridge structure to provide a stable reference ground potential, and detects the change of positive and negative voltage to ground through a voltage monitoring relay.

3. A DC power supply monitoring instrument with insulation monitoring function according to claim 1, characterized in that, The hardware system (31) includes a voltage acquisition module (311), a data processing module (312), and an alarm output module (313); the embedded software system (32) is used to realize voltage data acquisition, insulation status analysis, alarm judgment, and alarm count recording functions. The user interface module (33) is used to display voltage values, alarm status and historical information, and supports parameter setting and data export through a graphical interface.

4. A DC power supply monitoring instrument with insulation monitoring function according to claim 1, characterized in that, The alarm device (41) is an audible and visual alarm light, which is connected to the contacts of the voltage monitoring relay (22). When the voltage of the positive or negative terminal of the DC power supply system (1) to ground deviates from the set range, the alarm will be automatically triggered to remind the on-site personnel to deal with the insulation abnormality in a timely manner.

5. A DC power supply monitoring instrument with insulation monitoring function according to claim 1, characterized in that, The host computer (3) supports the access of DC power supply systems with multiple voltage levels. The built-in automatic identification module can detect the input voltage level and set different insulation alarm thresholds according to different voltage levels, so as to realize the monitoring of different test DC power supplies and grounding fault early warning.

6. A DC power supply monitoring instrument with insulation monitoring function according to claim 3, characterized in that, The voltage acquisition module (311) uses a differential amplifier circuit to acquire the positive and negative voltage signals of the system under test to ground.

7. A DC power supply monitoring instrument with insulation monitoring function according to claim 6, characterized in that, The voltage acquisition module (311) contains an amplifier, which is an operational amplifier and a data amplifier with low noise, low drift, low power consumption and high isolation.

8. A DC power supply monitoring instrument with insulation monitoring function according to claim 1 or 3, characterized in that, The user interface module (33) uses a touch screen display and supports setting alarm thresholds, sampling frequency and communication parameters through a graphical interface.

9. A DC power supply monitoring instrument with insulation monitoring function according to claim 1, characterized in that, The DC signal source (11) is a DC power supply with a rated voltage of 220V; the monitoring module (2) is set with a ground voltage deviation alarm threshold of 23V; and the communication bus is RS485 or CAN bus.

Images