CN201497782U - DC operating system insulation performance monitoring device - Google Patents

Abstract

The utility model relates to a device for monitoring the insulating property of a DC (direct current) operation system. The device is embedded between an equipment DC switch and an equipment DC control and replay protection system, and is characterized in that a first detection unit, a second detection unit and a third detection unit are included; an input terminal of the first detection unit is connected with a positive pole of the DC switch, and an output terminal of the first detection unit is connected with a positive pole input terminal of the equipment DC control and relay protection system, so that the first detection unit can be used for detecting the insulation performance of a DC positive pole; an input terminal of the second detection unit is connected with a negative pole of the DC switch, and an output terminal of the second detection unit is connected with a negative pole input terminal of the equipment DC control and relay protection system, so that the second detection unit can be used for detecting the insulation performance of a DC negative pole; and a positive pole and a negative pole of the third detection unit are respectively connected with the positive pole and the negative pole of the DC switch, and an earthing terminal of the third detection unit is connected with an earthing bus of a control cabinet, so that the third detection unit can be used for detecting the earthing performance of the DC positive and negative poles. Therefore, with the adoption of the utility model, the DC insulation failure equipment can be automatically judged and fast found out.

Description

DC operating system insulation performance monitoring device

technical field

The utility model relates to an electrical system monitoring device, in particular to an on-line substation DC system insulation performance detection device.

Background technique

The DC power supply of power plants and high-voltage substations is used as the security power supply and control signal power supply of the main electrical equipment. It is a very large multi-branch power supply network. The common fault is a point ground fault. The DC operating system in the power system adopts the ground insulation operation mode. The DC operating system runs for a long time, and the positive and negative ground insulations are often evenly reduced to a lower level. When a point is grounded, it does not cause any harm, but must be timely Otherwise, when another point is grounded, the relay protection equipment may malfunction or refuse to operate. It may even cause misoperation or refusal to operate the equipment using DC control, and even damage the equipment, resulting in serious consequences of large-scale power outages and system collapse. Therefore, in order to reduce this kind of insulation failure, there must be a reliable insulation monitoring method, so as to find problems in time and avoid major accidents.

At present, the known monitoring device for the DC positive and negative pole-to-ground insulation performance of the DC operating system of a high-voltage substation is composed of a voltage dividing resistor, a changeover switch, a relay, a voltmeter, and the like. Use a voltmeter to detect the voltage value of the positive and negative poles of the DC operating system to the ground to determine the insulation performance of the positive and negative poles to the ground, and use the voltage difference between the positive and negative poles of the DC operating system to drive the relay to send an alarm signal. However, this type of device can only detect and judge whether the insulation performance of the entire DC operating system is good or bad, and cannot find the faulty equipment number and fault point. In order to find the fault point, it is necessary to stop the DC control system of the high-voltage equipment one by one, or stop the DC bus in sections. When the DC control system is out of operation, the relay protection system of the equipment will lose its function, which poses a serious safety hazard to the high-voltage system.

Utility model content

The utility model is proposed to solve the above problems, and its purpose is to provide a DC operating system insulation performance monitoring device, which is embedded between the equipment DC switch and the equipment DC control and relay protection system. It is characterized in that it includes: the input terminal is connected to the positive pole of the DC switch, and the output terminal is connected to the positive pole input terminal of the equipment DC control and relay protection system, which is used to detect the insulation performance of the DC positive pole; the input terminal is connected to the first detection unit. The negative pole of the above-mentioned DC switch, and the output terminal is connected to the negative pole input terminal of the equipment DC control and relay protection system, which is used to detect the insulation performance of the DC negative pole. The second detection unit; the positive and negative poles are respectively connected to the positive and negative poles of the DC switch, And the ground terminal is connected to the ground bus bar of the control cabinet, which is used for the third detection unit to detect the grounding performance of the DC positive and negative poles.

The utility model also includes a conversion switch for respectively connecting the positive and negative poles of the DC switch of the equipment with the positive and negative poles of the DC control and relay protection system of the equipment.

The utility model also includes a DC power input wiring board for connecting the first detection unit or the second detection unit with the DC switch of the equipment and a wiring board for connecting the first detection unit or the second detection unit It is connected with the DC power output wiring board of the DC control and relay protection system of the equipment.

The first detection unit and the second detection unit respectively include a relay and a light-emitting diode connected in series with it, and when the current value passing through the relay is greater than 8mA, the light-emitting diode is turned on.

The first detection unit and the second detection unit respectively include an over-current voltage regulation protection circuit.

According to the insulation performance monitoring device of the DC operating system of the present invention, it can quickly and accurately determine and find the DC fault equipment, which can avoid the failure of the equipment control system of the entire busbar and the relay protection system If it loses its function, it will cause serious safety hazards to the high-voltage system.

Description of drawings

The above and other objects and features of the present invention will become more apparent through the following description in conjunction with the accompanying drawings exemplarily showing an example, wherein:

Fig. 1 is a brief schematic diagram of a DC operating system insulation performance monitoring device according to the present invention;

Fig. 2 is a schematic circuit configuration diagram of a DC operating system insulation performance monitoring device according to the utility model.

Explanation of main symbols: 100 is the equipment DC switch; 110 is the first detection unit; 120 is the second detection unit; 130 is the third detection unit; 140a is the first transfer switch; 140b is the second transfer switch; 150 is the equipment DC control And relay protection system; J1, J2, J3 are relays; D3, D7 are light-emitting diodes; D9 is indicator light.

Detailed ways

Hereinafter, preferred embodiments of the present utility model will be described in detail with reference to the accompanying drawings. Those skilled in the art should know that the embodiments and drawings described in this specification are only preferred embodiments of the present utility model, and do not represent all technical ideas of the present utility model, so there are various alternative embodiments.

The DC operating system insulation performance monitoring device of the present utility model is arranged in the high-voltage equipment control cabinet of the DC system, as shown in Figure 1 and Figure 2, the DC operating system insulation monitoring device is installed in the equipment DC switch 100 and the equipment DC control and The relay protection system 150 includes a casing (not shown), a first detection unit 110 , a second detection unit 120 , a third detection unit 130 , and first and second transfer switches 140 a and 140 b. The first detection unit 110 is arranged in the housing (not shown), its input terminal is connected to the positive pole of the equipment DC switch 100, and its output terminal is connected to the equipment DC control and relay protection system 150 positive pole, so as to It is used to test the insulation performance of DC positive pole. The second detection unit 120 is arranged in the housing (not shown), its input terminal is connected to the negative pole of the equipment DC switch 100, and its output terminal is connected to the negative pole of the equipment DC control and relay protection system 150, so as to It is used to test the insulation performance of DC negative pole. The third detection unit 130 is arranged in the housing (not shown), the positive and negative poles of which are respectively connected to the positive and negative poles of the DC switch 100, and the ground terminal is connected to the ground bus bar of the control cabinet for detecting the positive and negative poles of the DC grounding performance. The first and second transfer switches 140a and 140b are respectively connected to the positive and negative poles of the equipment DC switch 100 and the positive and negative poles of the equipment DC control and relay protection system 150 for selectively using the first detection unit 110 or the second detection unit 120 performs detection. In this way, when the first conversion switch 140a is turned off and the second conversion switch 140b is turned on, the first detection unit 110 and the third detection unit work; when the first conversion switch 140a is turned on When the switch 140b is turned on and the second switch 140b is turned off, the second detection unit 120 and the third detection unit work. It can be seen that the disconnection and conduction of the transfer switches 140a and 140b can control the insulation performance monitoring device of the DC operating system of the present invention to be put into operation or out of use. Those skilled in the art should know that only any one of the first, second and third detection units is reserved, and the detection unit can still work. The utility model also includes a DC power input wiring board and a DC power output wiring board (not shown), so that the first detection unit 110 and the second detection unit 120 can pass through the DC power input wiring board and the DC The power output wiring board is connected with the equipment DC switch 100 and the equipment DC control and relay protection system 150 . Here, those skilled in the art should know that the connection mode between the first detection unit 110 and the second detection unit 120 and the equipment DC switch 100 and the equipment DC control and relay protection system is not limited to the method in this embodiment. Wiring board connection, various connection methods can be adopted according to needs.

As shown in FIG. 2 , the first detection unit 110 includes a relay J1 , resistors R1 , R2 , a thyristor T1 , a voltage regulator tube D4 , rectifier diodes D1 , D2 , and a light emitting diode D3 . The relay J1 is a dry yellow relay, and its anode is connected to the anode of the DC switch 100 of the equipment. When the current passing through is greater than a predetermined value, its normally open output contact is closed to conduct the circuit, and when the passing current is less than a predetermined value, Its normally open output contacts remain unchanged and continue to break the circuit. The resistor R1 is connected in series with the relay J1 and is used as a current limiting resistor of the circuit. The light-emitting diode D3 is connected in series with the resistor R1, and when the current passing through it is greater than a predetermined value and the relay J1 is turned on, it is turned on to give an alarm to the user. The regulator tube D4 is connected in parallel with the relay J1, the resistor R1 and the light emitting diode D3. The rectifier diodes D1, D2 are connected in series with the resistor R2, and the rectifier diodes D1, D2, resistor R2 are connected in parallel with the regulator tube D4. The anode of the thyristor is connected to the anode of the rectifier diode D1 , the cathode is connected to the cathode of the regulator tube D4 , and the control electrode is connected to one end of the resistor R2 . The resistor R2 is a current limiting resistor of the thyristor trigger circuit. Thus, the rectifier diodes D1 , D2 , the regulator tube D4 , the resistor R2 , and the thyristor T1 constitute an overcurrent and voltage regulator protection circuit of the first detection unit 110 . When the circuit breaker is switching on and off, the positive and negative electrodes of the monitoring circuit pass through a large current (generally greater than 5A), which may damage the relay J1 or cause a malfunction of the relay J1 and cause an alarm. The utility model bypasses the large current generated when switching on and off by adding an overcurrent and voltage stabilizing protection circuit, thereby improving the stability of the equipment.

As shown in FIG. 2 , the second detection unit 120 includes a relay J2 , resistors R3 , R4 , a thyristor T2 , a voltage regulator tube D8 , rectifier diodes D5 , D6 , and a light emitting diode D7 . The relay J2 is a dry yellow relay, its positive pole is connected to the negative pole of the equipment DC switch 100 equipment DC control and relay protection system 150, when the current passing through is greater than a predetermined value, its normally open output contact is closed and the circuit is turned on, and When the passing current is less than a predetermined value, its normally open output contact remains unchanged and continues to break the circuit. The resistor R4 is connected in series with the relay J2 and is used as a current limiting resistor of the circuit. The light-emitting diode D7 is connected in series with the resistor R4, and when the passing current is greater than a predetermined value and the relay J2 is turned on, it is lit to give an alarm to the user. The regulator tube D8 is connected in parallel with the relay J2, the resistor R4, and the light emitting diode D7. The rectifier diodes D5, D6 are connected in series with the resistor R3, and the rectifier diodes D5, D6, resistor R3 are connected in parallel with the regulator tube D8. The positive pole of the thyristor T2 is connected to the positive pole of the rectifier diode D5, the negative pole is connected to the negative pole of the voltage regulator transistor D8, and the control pole is connected to one end of the resistor R3. The resistor R3 is a current limiting resistor of the thyristor trigger circuit. Thus, the rectifier diodes D5 , D6 , the regulator tube D8 , the resistor R3 , and the thyristor T2 constitute an overcurrent and voltage regulator protection circuit of the second detection unit 120 . When the circuit breaker is switching on and off, the positive and negative poles of the monitoring circuit pass through a large current (generally greater than 5A), which may damage the relay J2 or cause a malfunction of the relay J2 and cause an alarm. The utility model bypasses the large current generated when switching on and off by adding an overcurrent and voltage stabilizing protection circuit, thereby improving the stability of the equipment.

As shown in FIG. 2 , the third detection unit 130 includes a relay J3 , an indicator light D9 , and resistors R5 and R6 . The relay J3 is a DC voltage relay, J3a in the figure represents a normally open auxiliary contact, and J3b represents a coil. When either positive pole or negative pole of the DC system is grounded, the normally open auxiliary contact J3a is closed, and a switch alarm signal is sent out, whereby the indicator light D9 flickers to alert the user. The indicator light D9 is connected in series with the normally open auxiliary contact J3a, and gives an alarm to the user by being lit or flashing, that is, when the normally open auxiliary contact J3a is closed, the power is turned on and is lit or flashing. The resistor R5 is connected in series with the resistor R6, and R5 and R6 are connected in parallel with the normally open auxiliary contact J3a and the indicator light D9. The resistors R5, R6 and the resistors R1, R4 are used to set the current threshold, so the threshold can be changed by changing the resistance of the resistors as required. The resistance values of the resistors R1, R4, R5 and R6 can be adjusted by using resistor potentiometers. In this embodiment, the threshold values are 4mA and 8mA respectively, wherein 4mA is the maximum threshold value of the operating current when the DC system is in normal operation and the high-voltage circuit breaker does not switch on and off, and 8mA is the minimum value when the DC system insulation performance is low or grounded. current threshold. Therefore, when the insulation performance of the positive pole or the negative pole of the DC system is good, the current value passing through the relay J1 or J2 and the light-emitting diode D3 or D7 is less than 4mA, the light-emitting diode D3 or D7 will not be lit, and the relay J1 or J2 will not work ; When the insulation performance of the positive pole or the negative pole of the DC system is deteriorated or grounded, when the current value passing through the relay J1 or J2, the light-emitting diode D3 or D7 is > 8mA, the light-emitting diode D3 or D7 is lit, and the normal state of the relay J1 or J2 The open contact is closed, thereby sending an alarm signal.

Hereinafter, the working process according to the embodiment of the present utility model will be described with reference to FIG. 1 and FIG. 2 .

The insulation performance monitoring device of the DC operating system according to the embodiment of the utility model is set in the high-voltage equipment control cabinet of the DC system, wherein the input terminal of the first detection unit 110 is connected to the positive pole of the DC switch 100 of the equipment through the DC input wiring board, and the output The terminal is connected to the positive pole of the DC control and relay protection system of the equipment through the DC output wiring board; the input terminal of the second detection unit 120 is connected to the negative pole of the equipment DC switch 100 through the DC input wiring board, and the output terminal is connected to the negative pole of the equipment DC switch 100 through the DC output wiring board. The negative pole of the DC control and relay protection system of the equipment; the positive and negative poles of the third detection unit 130 are respectively connected to the positive and negative poles of the DC switch 100, and the ground terminal is connected to the ground bus bar of the control cabinet. The first and second transfer switches 140a and 140b are respectively connected to the positive and negative poles of the equipment DC switch 100 and the positive and negative poles of the equipment DC control and relay protection system 150 .

Firstly, by turning off the first and second transfer switches 140a and 140b at the same time, the insulation performance monitoring device of the DC operating system starts to work. At this time, if only the first conversion switch 140a is turned off, only the first detection unit 110 can work; on the contrary, if only the second conversion switch 140b is turned off, only the second detection unit can work.

Then, when the positive insulation performance of the DC system is good, the current value of the relay J1 and the light-emitting diode D3 is less than 4mA, the light-emitting diode D3 will not be lit, and the relay J1 will not act; when the positive insulation performance of the DC system When it becomes worse or grounded, the current value of the relay J1 and the light-emitting diode D3 is >8mA, the light-emitting diode D3 is lit, the relay J1 acts, its normally open contact is closed, and a switch alarm signal is sent. At the same time, the relay J3 of the third detection unit 130 is activated, and its normally open contact is closed, thus the indicator light D9 is turned on. At this time, since the light-emitting diode D3 and the indicator light D3 are turned on at the same time, the user can judge that the insulation performance of the positive pole of the DC system is deteriorated or grounded.

When the insulation performance of the negative electrode of the DC system is good, the current value of the relay J2 and the light-emitting diode D7 is less than 4mA, the light-emitting diode D7 will not be lit, and the relay J2 will not act; when the insulation performance of the negative electrode of the DC system becomes poor Or when grounded, the current value of the relay J2 and the light-emitting diode D7>8mA, the light-emitting diode D7 is lighted, the relay J2 makes an action, its normally open contact is closed, and a switch alarm signal is sent. At the same time, the relay J3 of the third detection unit 130 is activated, and its normally open contact is closed, thus the indicator light D9 is turned on. At this time, since the light-emitting diode D3 and the indicator light D3 are turned on at the same time, the user can judge that the insulation performance of the positive pole of the DC system is deteriorated or grounded.

It can be seen that through the lit or flashing indicator light D9, the user can know that there is an insulation fault in the DC system. At this time, the user can quickly judge that the DC system is faulty by further confirming whether the light-emitting diode D3 or D7 is lit. Whether there is an insulation fault in the positive pole or an insulation fault in the negative pole of the DC system, or the positive and negative poles of the DC system are faulty at the same time. Those skilled in the art should know that the insulation performance monitoring device of the DC operating system according to the present invention can be installed in each DC equipment to realize insulation monitoring, and the relays J1 and J2 of the detection units in each detection device can be connected to the signal PLC and controller background, thus realizing real-time automatic alarm monitoring and report printing.

The above-described embodiments are only illustrative rather than restrictive, and any equivalent modifications or changes that do not deviate from the spirit of the utility model are included in the scope of claims of the utility model.

Claims (5)

1. dc operation system insulation performance monitoring device, this insulating property monitoring device embeds and is arranged between equipment dc switch and equipment DC control and the relay protection system, it is characterized in that comprising:

Input end connects the positive pole of described dc switch, and the electrode input end of output terminal connection device DC control and relay protection system, with first detecting unit of the insulating property that are used to detect direct-flow positive pole;

Input end connects the negative pole of described dc switch, and the negative input of output terminal connection device DC control and relay protection system, with second detecting unit of the insulating property that are used to detect the direct current negative pole;

Both positive and negative polarity connects the both positive and negative polarity of dc switch respectively, and earth terminal connects the switch board ground strap, with the 3rd detecting unit of the ground connection performance that is used to detect the direct current both positive and negative polarity.

2. dc operation system insulation performance monitoring device according to claim 1 is characterized in that also comprising the switch of the both positive and negative polarity of the both positive and negative polarity of connection device dc switch respectively and equipment DC control and relay protection system.

3. dc operation system insulation performance monitoring device according to claim 1 is characterized in that also comprising and is used to connect described first detecting unit or described second detecting unit and the direct supply input panel of described equipment dc switch and the direct supply output wiring board that is used to be connected described first detecting unit or described second detecting unit and described equipment DC control and relay protection system.

4. dc operation system insulation performance monitoring device according to claim 1, it is characterized in that described first detecting unit and second detecting unit comprise the light emitting diode of relay and series connection with it connection respectively, when the current value by relay during greater than 8mA, described light emitting diode is lighted.

5. dc operation system insulation performance monitoring device according to claim 1 is characterized in that described first detecting unit and second detecting unit comprise the overcurrent protective circuit of voltage regulation respectively.