Main transformer non-electric quantity protection control circuit and working method

Abstract

The invention relates to the technical field of transformer protection control, and particularly discloses a main transformer non-electric quantity protection control circuit and a working method, and the circuit comprises a main transformer non-electric quantity signal collection circuit, a main transformer non-electric quantity signal alarm circuit, a main transformer non-electric quantity protection tripping starting circuit, and a main transformer non-electric quantity protection circuit breaker tripping circuit. When a main transformer has an abnormal working fault or defect, contacts of corresponding non-electric quantity protection signals such as non-electric quantity protection, high oil temperature, on-load light gas, on-load gas, cold control power loss, body light gas, body heavy gas and pressure release on site are closed, and a direct-current power supply is connected with a corresponding signal acquisition circuit; a corresponding non-electric quantity protection relay coil is electrified, and a corresponding normally open contact of the non-electric quantity protection relay can be respectively connected with a main transformer non-electric quantity signal alarm circuit and a main transformer non-electric quantity tripping starting circuit; protection tripping of high-voltage and low-voltage circuit breakers on the two sides of the main transformer can be achieved, and safety of a power supply system is

Description

Technical Field

[0001] The present invention relates to the technical field of transformer protection control, and in particular to a main transformer non-electrical quantity protection control circuit and a working method. Background Art

[0002] Transformers are important electrical equipment in the power system of substations. Differential protection and gas protection are the main protections of main transformers. When a serious (short circuit) fault occurs in the differential protection zone of the main transformer or a fault occurs outside the non-electrical area of ​​the transformer, an unbalanced current will be generated. When a serious fault occurs inside the main transformer, the main protection should act quickly and accurately to cut off the fault and avoid the expansion of the accident. In the prior art, some faults will have some hidden dangers before they occur. Therefore, if early warnings and processing are issued in time when faults and hidden dangers occur, or protection tripping is performed in some serious fault conditions, the expansion of the fault range can be avoided. Therefore, it is very important to timely obtain non-electrical fault information such as the temperature, gas, air cooling power loss, pressure of the main transformer body, and gas of the tap switch, and to issue alarms and tripping signals in real time. To this end, a main transformer non-electrical protection control circuit and a working method are provided to solve the problem that the existing transformer protection circuit cannot effectively pre-identify the hidden dangers of the fault, so as to realize the effective early warning of the non-electrical protection under the hidden danger and fault state of the main transformer and the protection tripping of the high and low voltage circuit breakers on both sides of the main transformer under the fault condition, so as to ensure the safety of the power supply system. Summary of the invention

[0003] In view of the problems existing in the prior art, the purpose of the present invention is to provide a main transformer non-electrical quantity protection control circuit and working method, which can effectively warn when the main transformer has hidden dangers or faults, and protect the high and low voltage circuit breakers on both sides of the main transformer from tripping in the case of more serious faults, thereby ensuring the safety of the power supply system.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a main transformer non-electrical quantity protection control circuit, including a main transformer non-electrical quantity signal collection circuit, a main transformer non-electrical quantity signal alarm circuit, a main transformer non-electrical quantity protection tripping start circuit and a main transformer non-electrical quantity protection circuit breaker tripping circuit, the main transformer non-electrical quantity signal collection circuit includes but is not limited to an oil temperature high signal collection branch, a loaded light gas signal collection branch, a loaded heavy gas signal collection branch, a cold control power failure signal collection branch, a main body light gas signal collection branch, a main body heavy gas signal collection branch, and a pressure release signal collection branch connected in parallel to each other, and the collection branches of the main transformer non-electrical quantity signal collection circuit are all connected in parallel to the positive and negative electrodes of a DC power supply;

[0005] The main transformer non-electric signal alarm circuit includes but is not limited to a high oil temperature alarm branch, a light gas alarm branch under load, a heavy gas alarm branch under load, a cold control power failure alarm branch, a light gas alarm branch of the main body, a heavy gas alarm branch of the main body, and a pressure release alarm branch;

[0006] The main transformer non-electrical quantity protection tripping starting circuit includes but is not limited to a DC power supply, a non-electrical quantity protection tripping starting coil, and a main body heavy gas tripping starting branch, a load gas tripping starting branch, a pressure release tripping starting branch, and an ultra-high temperature tripping starting branch connected in parallel.

[0007] The main transformer non-electrical quantity protection circuit breaker tripping circuit includes a main transformer non-electrical quantity protection high-voltage side circuit breaker tripping circuit and a main transformer non-electrical quantity protection low-voltage side circuit breaker tripping circuit. The main transformer non-electrical quantity protection high-voltage side circuit breaker tripping circuit includes a DC power supply, a main transformer high-voltage side circuit breaker non-electrical quantity protection tripping output relay normally open contact, a high-voltage side circuit breaker non-electrical quantity protection tripping pressure plate, a tripping holding relay 1, a main transformer high-voltage side circuit breaker auxiliary normally open contact, and a main transformer high-voltage side circuit breaker tripping coil; the main transformer non-electrical quantity protection low-voltage side circuit breaker tripping circuit includes a DC power supply, a main transformer low-voltage side circuit breaker non-electrical quantity protection tripping output relay normally open contact, a low-voltage side circuit breaker non-electrical quantity protection tripping pressure plate, a tripping holding relay 2, a main transformer low-voltage side circuit breaker auxiliary normally open contact, and a main transformer low-voltage side circuit breaker tripping coil.

[0008] Specifically, the first normally open contact of the high oil temperature electric contact pressure and the high oil temperature relay coil are connected in series on the high oil temperature signal collection branch; the normally open contact of the loaded light gas and the loaded light gas relay coil are connected in series on the loaded light gas signal collection branch; the first normally open contact of the loaded gas and the loaded gas relay coil are connected in series on the loaded gas signal collection branch; the normally open contact of the cold control power failure and the cold control power failure relay coil are connected in series on the cold control power failure signal collection branch; the normally open contact of the main body light gas and the main body light gas relay coil are connected in series on the main body light gas signal collection branch; the first normally open contact of the main body weight gas and the main body weight gas relay coil are connected in series on the main body weight gas signal collection branch; the first normally open contact of the pressure release and the pressure release relay coil are connected in series on the pressure release signal collection branch.

[0009] Specifically, the light-loaded gas signal collection branch and the heavy-loaded gas signal collection branch share a DC positive power supply line; the main body light-loaded gas signal collection branch and the main body heavy-loaded gas signal collection branch share a DC positive power supply line;

[0010] The first normally open contact of the high oil temperature electric contact pressure is located in the oil temperature electric contact pressure gauge installed on the main transformer. The loaded light gas normally open contact and the loaded heavy gas first normally open contact are both installed in the loaded gas relay on the pipeline between the loaded oil pillow and the oil tank of the main transformer. The cold control power-off normally open contact is installed in the air-cooled control box of the main transformer body. The main body light gas normally open contact and the main body heavy gas first normally open contact are installed in the gas relay on the pipeline between the main transformer main body oil pillow and the oil tank. The first normally open contact of pressure release is installed in the pressure release valve on the main transformer main body oil tank. The high oil temperature relay coil, the loaded light gas relay coil, the loaded gas relay coil, the cold control power-off relay coil, the main body light gas relay coil, the main body heavy gas relay coil and the pressure release relay coil are all located in the non-electrical protection measurement and control device.

[0011] Specifically, the high oil temperature alarm branch is provided with the first normally open contact of the main transformer high oil temperature relay; the light-load gas alarm branch is provided with the normally open contact of the light-load gas relay; the heavy-load gas alarm branch is provided with the first normally open contact of the heavy-load gas relay; the cold control power failure alarm branch is provided with the normally open contact of the cold control power failure relay; the main body light gas alarm branch is provided with the normally open contact of the main body light gas relay; the main body heavy gas alarm branch is provided with the first normally open contact of the main body heavy gas relay; the pressure release alarm branch is provided with the first normally open contact of the pressure release relay;

[0012] The first normally open contact of the main transformer oil high temperature relay, the normally open contact of the loaded light gas relay, the first normally open contact of the loaded heavy gas relay, the normally open contact of the cold control power failure relay, the normally open contact of the main body light gas relay, the first normally open contact of the main body heavy gas relay, and the first normally open contact of the pressure release relay are all located in the non-electrical protection measurement and control device.

[0013] Specifically, the DC positive power supplies of the high oil temperature alarm branch, the loaded light gas alarm branch and the loaded heavy gas alarm branch share a power terminal, the DC positive power supplies of the cold control power failure alarm branch, the main body light gas alarm branch, the main body heavy gas alarm branch and the pressure release alarm branch share a power terminal, and the DC positive power supplies are all connected to the positive pole of the DC power supply.

[0014] Specifically, the second normally open contact of the main body heavy gas and the main body heavy gas protection tripping pressure plate connected in series on the main body heavy gas tripping starting branch, the second normally open contact of the load gas and the load gas protection tripping pressure plate connected in series on the load gas tripping starting branch, the second normally open contact of the pressure release and the pressure release protection tripping pressure plate connected in series on the pressure release tripping starting branch, and the second normally open contact of the ultra-high temperature and the ultra-high temperature protection tripping pressure plate connected in series on the ultra-high temperature tripping starting branch;

[0015] The second normally open contact of the main body's heavy gas, the second normally open contact of the loaded gas, the second normally open contact of the pressure release, and the second normally open contact of the ultra-high temperature are all located in the non-electrical protection measurement and control device.

[0016] Specifically, the positive pole of the DC power supply of the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit is connected to one end of the normally open contact of the main transformer high-voltage side circuit breaker non-electrical protection tripping output relay, the other end of the normally open contact of the main transformer high-voltage side circuit breaker non-electrical protection tripping output relay is connected to one end of the high-voltage side circuit breaker non-electrical protection tripping pressure plate, the other end of the high-voltage side circuit breaker non-electrical protection tripping pressure plate is connected to one end of the tripping holding relay one, the other end of the tripping holding relay one is connected to one end of the auxiliary normally open contact of the main transformer high-voltage side circuit breaker, the other end of the auxiliary normally open contact of the main transformer high-voltage side circuit breaker is connected to one end of the main transformer high-voltage side circuit breaker opening coil, and the other end of the main transformer high-voltage side circuit breaker opening coil is connected to the negative pole of the DC power supply;

[0017] The positive pole of the DC power supply of the tripping circuit of the low-voltage side circuit breaker of the main transformer non-electrical protection is connected to one end of the normally open contact of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer, the other end of the normally open contact of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer is connected to one end of the non-electrical protection tripping pressure plate of the low-voltage side circuit breaker, the other end of the non-electrical protection tripping pressure plate of the low-voltage side circuit breaker is connected to one end of the trip holding relay 2, the other end of the trip holding relay 2 is connected to one end of the auxiliary normally open contact of the low-voltage side circuit breaker of the main transformer, the other end of the auxiliary normally open contact of the low-voltage side circuit breaker of the main transformer is connected to one end of the opening coil of the low-voltage side circuit breaker of the main transformer, and the other end of the opening coil of the low-voltage side circuit breaker of the main transformer is connected to the negative pole of the DC power supply.

[0018] Specifically, the self-holding contacts of the trip holding relay 1 and the trip holding relay 2 are respectively connected in parallel to the positive pole of the DC power supply and one end of the coil of the trip holding relay; the self-holding contacts of the trip holding relay 1 and the trip holding relay 2 and their coils are both located inside the microcomputer protection measurement and control device.

[0019] Specifically, the states of the normally open contacts of the non-electrical protection tripping output relay of the high-voltage side circuit breaker of the main transformer and the normally open contacts of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer are respectively controlled by their own non-electrical protection tripping output relays; the normally open contacts and coils of the non-electrical protection tripping output relay of the high-voltage side circuit breaker of the main transformer and the normally open contacts and coils of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer are both located inside the microcomputer protection and measurement and control device.

[0020] A working method of a main transformer non-electrical quantity protection control circuit comprises the following steps:

[0021] S1. When the main transformer has abnormal working or equipment defects, the relevant contacts of the non-electrical protection signals of the corresponding on-site non-electrical protection, such as high oil temperature, light gas on load, heavy gas on load, cold control power failure, light gas on the main body, heavy gas on the main body, and pressure release, will be closed, the DC power supply will connect the corresponding signal acquisition branch, the corresponding non-electrical protection relay coil will be energized, and the corresponding normally open contacts of the non-electrical protection relay will connect the main transformer non-electrical signal alarm circuit and the main transformer non-electrical protection trip start circuit respectively;

[0022] S2. When any of the normally open contacts of non-electrical alarms such as high oil temperature, light gas on load, heavy gas on load, power failure of cold control, light gas on body, heavy gas on body, and pressure release is closed, the DC power supply will connect the corresponding non-electrical signal alarm circuit of the main transformer, and issue the corresponding non-electrical signal alarm, which will be transmitted to the background monitoring microcomputer through the communication interface of the microcomputer protection measurement and control device via the communication line, and an abnormal alarm message will be issued to prompt the on-duty personnel to pay attention and handle it;

[0023] S3. When any of the tripping contacts of the main transformer body's heavy gas, load gas, pressure release, and over-high temperature is closed and connected, the DC power supply will connect the corresponding main transformer non-electrical protection tripping starting circuit through the corresponding non-electrical protection tripping pressure plate, and the main transformer non-electrical protection tripping output relay coil will be energized. The corresponding normally open contacts of the main transformer non-electrical protection tripping output relay can connect the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit and the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit, and disconnect the circuit breakers on both the high and low voltage sides of the main transformer.

[0024] The present invention has the following beneficial effects:

[0025] The main transformer non-electrical quantity protection control circuit and working method designed by the present invention can realize the protection tripping of high and low voltage circuit breakers on both sides of the main transformer in the event of non-electrical quantity protection effective warning and failure in the hidden danger state of the main transformer, thereby ensuring the safety of the power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a block diagram of the main transformer non-electrical protection control circuit.

[0027] Figure 2 It is the circuit diagram of the main transformer non-electrical quantity signal acquisition circuit.

[0028] Figure 3 This is the circuit diagram of the main transformer non-electrical quantity signal alarm circuit.

[0029] Figure 4 It is the circuit diagram of the main transformer non-electrical quantity protection tripping starting circuit.

[0030] Figure 5 It is the circuit diagram of the main transformer non-electrical quantity protection circuit breaker tripping circuit. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely further describe the technical solutions in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] like Figure 1-Figure 5 As shown, a main transformer non-electrical quantity protection control circuit can effectively warn when the main transformer has hidden dangers or faults, and can protect the high and low voltage circuit breakers on both sides of the main transformer from tripping in the case of more serious faults, thereby ensuring the safety of the power supply system.

[0033] like Figure 1 As shown, a main transformer non-electric quantity protection control circuit includes a main transformer non-electric quantity signal acquisition circuit, a main transformer non-electric quantity signal alarm circuit, a main transformer non-electric quantity protection tripping start circuit and a main transformer non-electric quantity protection circuit breaker tripping circuit.

[0034] like Figure 2 As shown, the main transformer non-electrical signal collection circuit includes an oil temperature high signal collection branch, a loaded light gas signal collection branch, a loaded heavy gas signal collection branch, a cold control power failure signal collection branch, a main body light gas signal collection branch, a main body heavy gas signal collection branch, and a pressure release signal collection branch, which are connected in parallel to each other. The collection branches of the main transformer non-electrical signal collection circuit are all connected in parallel to the positive pole +KM and the negative pole -KM of the DC power supply.

[0035] The first normally open contacts ①, ② of the high oil temperature electric contact pressure and the high oil temperature relay J1 coil connected in series on the high oil temperature signal collection branch; the normally open contacts ①, ② of the loaded light gas and the J2 coil of the loaded light gas relay connected in series on the loaded light gas signal collection branch; the first normally open contacts ①, ② of the loaded gas and the J3 coil of the loaded gas relay connected in series on the loaded gas signal collection branch; the normally open contacts ①, ② of the cold control power failure and the J5 coil of the cold control power failure relay connected in series on the cold control power failure signal collection branch; the normally open contacts ①, ② of the main body light gas and the J6 coil of the main body light gas relay connected in series on the main body light gas signal collection branch; the first normally open contacts ①, ② of the main body heavy gas and the J7 coil of the main body heavy gas relay connected in series on the main body heavy gas signal collection branch; the first normally open contacts ①, ② of the pressure release and the J8 coil of the pressure release relay connected in series on the pressure release signal collection branch.

[0036] The loaded light gas signal collection branch and the loaded heavy gas signal collection branch share a DC positive power supply line; the main body light gas signal collection branch and the main body heavy gas signal collection branch share a DC positive power supply line.

[0037] The first normally open contacts ① and ② of the high oil temperature electric contact pressure are located in the oil temperature electric contact pressure gauge installed on the main transformer. The normally open contacts ① and ② of the light gas on load and the first normally open contacts ① and ② of the heavy gas on load are both installed in the on-load gas relay on the pipeline between the on-load oil pillow and the oil tank of the main transformer. The normally open contacts ① and ② of the cold control power failure are installed in the air-cooled control box of the main transformer body. The normally open contacts ① and ② of the light gas on the main body and the first normally open contacts ① and ② of the heavy gas on the main body are installed in the gas relay on the pipeline between the oil pillow and the oil tank of the main transformer body. The first normally open contacts ① and ② of the pressure release are installed in the pressure release valve on the main transformer body oil tank. The coil of the high oil temperature relay J1, the coil of the light gas on load relay J2, the coil of the heavy gas relay J3, the coil of the cold control power failure relay J5, the coil of the light gas on the main body relay J6, the coil of the heavy gas on the main body relay J7 and the coil of the pressure release relay J8 are all located in the non-electrical protection measurement and control device.

[0038] like Figure 3 As shown, the main transformer non-electrical signal alarm circuit includes but is not limited to high oil temperature alarm branch, loaded light gas alarm branch, loaded heavy gas alarm branch, cold control power failure alarm branch, main body light gas alarm branch, main body heavy gas alarm branch and pressure release alarm branch.

[0039] The high oil temperature alarm branch is provided with the first normally open contact J11 of the main transformer high oil temperature relay; the on-load light gas alarm branch is provided with the normally open contact J2 of the on-load light gas relay; the on-load heavy gas alarm branch is provided with the first normally open contact J31 of the on-load gas relay; the cold control power failure alarm branch is provided with the normally open contact J5 of the cold control power failure relay; the main body light gas alarm branch is provided with the normally open contact J6 of the main body light gas relay; the main body heavy gas alarm branch is provided with the first normally open contact J71 of the main body relay; the pressure release alarm branch is provided with the first normally open contact J81 of the pressure release relay.

[0040] The first normally open contact J11 of the main transformer oil high temperature relay, the normally open contact J2 of the loaded light gas relay, the first normally open contact J31 of the loaded heavy gas relay, the normally open contact J5 of the cold control power failure relay, the normally open contact J6 of the main body light gas relay, the first normally open contact J71 of the main body heavy gas relay, and the first normally open contact J81 of the pressure release relay are all located in the non-electrical protection measurement and control device.

[0041] The DC positive power supplies of the high oil temperature alarm branch, the loaded light gas alarm branch and the loaded heavy gas alarm branch share a power connection terminal, the DC positive power supplies of the cold control power failure alarm branch, the main body light gas alarm branch, the main body heavy gas alarm branch and the pressure release alarm branch share a power connection terminal, and the DC positive power supplies of each alarm branch are connected to the positive pole +KM of the DC power supply.

[0042] like Figure 4As shown, the main transformer non-electrical protection tripping starting circuit includes but is not limited to a DC power supply ±KM, a non-electrical protection tripping starting coil BTJ, and a main body weight gas tripping starting branch, a load gas tripping starting branch, a pressure release tripping starting branch, and an ultra-high temperature tripping starting branch connected in parallel.

[0043] The second normally open contact J72 of the main body heavy gas and the main body heavy gas protection tripping pressure plate 4LP1 are connected in series on the main body heavy gas tripping starting branch, the second normally open contact J32 of the load gas and the load gas protection tripping pressure plate 4LP2 are connected in series on the load gas tripping starting branch, the second normally open contact J82 of the pressure release and the pressure release protection tripping pressure plate 4LP3 are connected in series on the pressure release tripping starting branch, and the second normally open contact J12 of the ultra-high temperature and the ultra-high temperature protection tripping pressure plate 4LP4 are connected in series on the ultra-high temperature tripping starting branch.

[0044] The second normally open contact J72 of the main body's heavy gas, the second normally open contact J32 of the loaded gas, the second normally open contact J82 of the pressure release, and the second normally open contact J12 of the ultra-high temperature are all located in the non-electrical protection measurement and control device.

[0045] like Figure 5 As shown in the figure, the main transformer non-electrical quantity protection circuit breaker tripping circuit includes the main transformer non-electrical quantity protection high-voltage side circuit breaker tripping circuit and the main transformer non-electrical quantity protection low-voltage side circuit breaker tripping circuit. The main transformer non-electrical quantity protection high-voltage side circuit breaker tripping circuit includes a DC power supply ±KM, a main transformer high-voltage side circuit breaker non-electrical quantity protection tripping output relay normally open contact BTJ-1, a high-voltage side circuit breaker non-electrical quantity protection tripping pressure plate 4LP7, a tripping holding relay TBJ-1, a main transformer high-voltage side circuit breaker The auxiliary normally open contact QF1 of the circuit breaker on the high-voltage side of the main transformer, and the tripping coil TQ1 of the circuit breaker on the low-voltage side of the main transformer; the tripping circuit of the circuit breaker on the low-voltage side of the main transformer non-electrical protection includes the DC power supply ±KM, the normally open contact BTJ-2 of the non-electrical protection tripping output relay of the circuit breaker on the low-voltage side of the main transformer, the non-electrical protection tripping pressure plate 4LP9 of the circuit breaker on the low-voltage side, the tripping holding relay TBJ-2, ​​the auxiliary normally open contact QF2 of the circuit breaker on the low-voltage side of the main transformer, and the tripping coil TQ2 of the circuit breaker on the low-voltage side of the main transformer.

[0046] The positive pole +KM of the DC power supply of the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit is connected to one end of the normally open contact BTJ-1 of the non-electrical protection tripping output relay of the main transformer high-voltage side circuit breaker, the other end of the normally open contact BTJ-1 of the non-electrical protection tripping output relay of the main transformer high-voltage side circuit breaker is connected to one end of the non-electrical protection tripping pressure plate 4LP7 of the high-voltage side circuit breaker, the other end of the non-electrical protection tripping pressure plate 4LP7 of the high-voltage side circuit breaker is connected to one end of the trip holding relay TBJ-1, the other end of the trip holding relay TBJ-1 is connected to one end of the auxiliary normally open contact QF1 of the main transformer high-voltage side circuit breaker, the other end of the auxiliary normally open contact QF1 of the main transformer high-voltage side circuit breaker is connected to one end of the main transformer high-voltage side circuit breaker opening coil TQ1, and the other end of the main transformer high-voltage side circuit breaker opening coil TQ1 is connected to the negative pole -KM of the DC power supply.

[0047] The positive pole +KM of the DC power supply of the main transformer non-electrical protection low-voltage side circuit breaker tripping circuit is connected to one end of the normally open contact BTJ-2 of the non-electrical protection tripping output relay of the main transformer low-voltage side circuit breaker, the other end of the normally open contact BTJ-2 of the non-electrical protection tripping output relay of the main transformer low-voltage side circuit breaker is connected to one end of the non-electrical protection tripping pressure plate 4LP9 of the low-voltage side circuit breaker, the other end of the non-electrical protection tripping pressure plate 4LP9 of the low-voltage side circuit breaker is connected to one end of the trip holding relay 2 TBJ-2, ​​the other end of the trip holding relay 2 TBJ-2 is connected to one end of the auxiliary normally open contact QF2 of the main transformer low-voltage side circuit breaker, the other end of the auxiliary normally open contact QF2 of the main transformer low-voltage side circuit breaker is connected to one end of the main transformer low-voltage side circuit breaker opening coil TQ2, and the other end of the main transformer low-voltage side circuit breaker opening coil TQ2 is connected to the negative pole -KM of the DC power supply.

[0048] The self-holding contacts of the trip holding relay TBJ-1 and the trip holding relay TBJ-2 are respectively connected in parallel to the positive pole +KM of the DC power supply and one end of the coil of the trip holding relay; the self-holding contacts and coils of the trip holding relay TBJ-1 and the trip holding relay TBJ-2 are both located inside the microcomputer protection measurement and control device.

[0049] The states of the normally open contact BTJ-1 of the non-electrical protection tripping output relay of the high-voltage side circuit breaker of the main transformer and the normally open contact BTJ-2 of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer are controlled by the non-electrical protection tripping output relay; the normally open contact BTJ-1 of the non-electrical protection tripping output relay of the high-voltage side circuit breaker of the main transformer and its coil and the normally open contact BTJ-2 of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer and its coil are both located inside the microcomputer protection and measurement and control device.

[0050] The DC working power supply voltage of the main transformer microcomputer non-electrical protection control circuit is 220V.

[0051] The non-electrical protection of each device in the main transformer non-electrical protection control circuit can be activated or deactivated by an independent soft pressure plate. Each non-electrical protection can be selected to alarm or trip through an independent control word (setting to "0" means alarm, setting to "1" means trip).

[0052] The working principle of the main transformer non-electrical quantity protection control circuit is as follows:

[0053] 1. When the main transformer has an abnormal operation or equipment defect, the relevant contacts of the non-electrical protection signals of the corresponding on-site non-electrical protection, such as high oil temperature, light gas on load, heavy gas on load, power failure of cold control, light gas on the main body, heavy gas on the main body, and pressure release will be closed, the DC power supply will be connected to the corresponding signal acquisition branch, the corresponding non-electrical protection relay coil will be energized, and the corresponding normally open contacts of the non-electrical protection relay will be connected to the main transformer non-electrical signal alarm circuit and the main transformer non-electrical protection tripping start circuit respectively.

[0054] 2. When any of the normally open contacts of non-electrical alarm such as high oil temperature, light gas on load, heavy gas on load, power failure of cold control, light gas on body, heavy gas on body, and pressure release is closed, the DC power supply will connect the corresponding main transformer non-electrical signal alarm circuit and send out the corresponding non-electrical signal alarm, which will be transmitted to the background monitoring microcomputer through the communication interface of the microcomputer protection and measurement and control device via the communication line, and an abnormal alarm message will be issued to prompt the on-duty personnel to pay attention and handle it.

[0055] 3. When any of the tripping contacts of the main transformer body's heavy gas, load gas, pressure release, and ultra-high temperature is closed and connected, the DC power supply will connect the corresponding main transformer non-electrical protection tripping starting circuit through the corresponding non-electrical protection tripping pressure plate, and the main transformer non-electrical protection tripping output relay coil will be energized. The corresponding normally open contacts of the main transformer non-electrical protection tripping output relay can connect the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit and the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit, and disconnect the circuit breakers on both sides of the main transformer high and low voltage.

[0056] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.

[0057] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A main transformer non-electrical quantity protection control circuit, characterized in that: It includes a main transformer non-electrical quantity signal collection circuit, a main transformer non-electrical quantity signal alarm circuit, a main transformer non-electrical quantity protection tripping start circuit and a main transformer non-electrical quantity protection circuit breaker tripping circuit. The main transformer non-electrical quantity signal collection circuit includes but is not limited to an oil temperature high signal collection branch, a loaded light gas signal collection branch, a loaded heavy gas signal collection branch, a cold control power failure signal collection branch, a main body light gas signal collection branch, a main body heavy gas signal collection branch, and a pressure release signal collection branch connected in parallel to each other. The collection branches of the main transformer non-electrical quantity signal collection circuit are all connected in parallel to the positive and negative electrodes of the DC power supply; The main transformer non-electric signal alarm circuit includes but is not limited to a high oil temperature alarm branch, a light gas alarm branch under load, a heavy gas alarm branch under load, a cold control power failure alarm branch, a light gas alarm branch of the main body, a heavy gas alarm branch of the main body, and a pressure release alarm branch; The main transformer non-electrical quantity protection tripping start circuit includes but is not limited to a DC power supply, a non-electrical quantity protection tripping start coil, and a main body heavy gas tripping start branch, a load gas tripping start branch, a pressure release tripping start branch, and an ultra-high temperature tripping start branch connected in parallel; The main transformer non-electrical quantity protection circuit breaker tripping circuit includes a main transformer non-electrical quantity protection high-voltage side circuit breaker tripping circuit and a main transformer non-electrical quantity protection low-voltage side circuit breaker tripping circuit. The main transformer non-electrical quantity protection high-voltage side circuit breaker tripping circuit includes a DC power supply, a main transformer high-voltage side circuit breaker non-electrical quantity protection tripping output relay normally open contact, a high-voltage side circuit breaker non-electrical quantity protection tripping pressure plate, a tripping holding relay 1, a main transformer high-voltage side circuit breaker auxiliary normally open contact, and a main transformer high-voltage side circuit breaker tripping coil; the main transformer non-electrical quantity protection low-voltage side circuit breaker tripping circuit includes a DC power supply, a main transformer low-voltage side circuit breaker non-electrical quantity protection tripping output relay normally open contact, a low-voltage side circuit breaker non-electrical quantity protection tripping pressure plate, a tripping holding relay 2, a main transformer low-voltage side circuit breaker auxiliary normally open contact, and a main transformer low-voltage side circuit breaker tripping coil.

2. The main transformer non-electrical quantity protection control circuit according to claim 1 is characterized in that: The first normally open contact of the high oil temperature electric contact pressure and the high oil temperature relay coil connected in series on the high oil temperature signal collection branch; the normally open contact of the loaded light gas and the loaded light gas relay coil connected in series on the loaded light gas signal collection branch; the first normally open contact of the loaded gas and the loaded gas relay coil connected in series on the loaded gas signal collection branch; the normally open contact of the cold control power failure and the cold control power failure relay coil connected in series on the cold control power failure signal collection branch; the normally open contact of the main body light gas and the main body light gas relay coil connected in series on the main body light gas signal collection branch; the first normally open contact of the main body weight gas and the main body weight gas relay coil connected in series on the main body weight gas signal collection branch; the first normally open contact of the pressure release and the pressure release relay coil connected in series on the pressure release signal collection branch.

3. The main transformer non-electrical quantity protection control circuit according to claim 2 is characterized in that: The light-loaded gas signal collection branch and the heavy-loaded gas signal collection branch share a DC positive power supply line; the main body light-loaded gas signal collection branch and the main body heavy-loaded gas signal collection branch share a DC positive power supply line; The first normally open contact of the high oil temperature electric contact pressure is located in the oil temperature electric contact pressure gauge installed on the main transformer. The loaded light gas normally open contact and the loaded heavy gas first normally open contact are both installed in the loaded gas relay on the pipeline between the loaded oil pillow and the oil tank of the main transformer. The cold control power-off normally open contact is installed in the air-cooled control box of the main transformer body. The main body light gas normally open contact and the main body heavy gas first normally open contact are installed in the gas relay on the pipeline between the main transformer main body oil pillow and the oil tank. The first normally open contact of pressure release is installed in the pressure release valve on the main transformer main body oil tank. The high oil temperature relay coil, the loaded light gas relay coil, the loaded gas relay coil, the cold control power-off relay coil, the main body light gas relay coil, the main body heavy gas relay coil and the pressure release relay coil are all located in the non-electrical protection measurement and control device.

4. The main transformer non-electrical quantity protection control circuit according to claim 1 is characterized in that: The high oil temperature alarm branch is provided with the first normally open contact of the main transformer oil temperature high relay; the light-load gas alarm branch is provided with the normally open contact of the light-load gas relay; the heavy-load gas alarm branch is provided with the first normally open contact of the heavy-load gas relay; the cold control power failure alarm branch is provided with the normally open contact of the cold control power failure relay; the main body light gas alarm branch is provided with the normally open contact of the main body light gas relay; the main body heavy gas alarm branch is provided with the first normally open contact of the main body heavy gas relay; the pressure release alarm branch is provided with the first normally open contact of the pressure release relay; The first normally open contact of the main transformer oil high temperature relay, the normally open contact of the loaded light gas relay, the first normally open contact of the loaded heavy gas relay, the normally open contact of the cold control power failure relay, the normally open contact of the main body light gas relay, the first normally open contact of the main body heavy gas relay, and the first normally open contact of the pressure release relay are all located in the non-electrical protection measurement and control device.

5. The main transformer non-electrical quantity protection control circuit according to claim 4 is characterized in that: The DC positive power supplies of the high oil temperature alarm branch, the loaded light gas alarm branch and the loaded heavy gas alarm branch share a power connection terminal, the DC positive power supplies of the cold control power failure alarm branch, the main body light gas alarm branch, the main body heavy gas alarm branch and the pressure release alarm branch share a power connection terminal, and the DC positive power supplies are all connected to the positive pole of the DC power supply.

6. The main transformer non-electrical quantity protection control circuit according to claim 1 is characterized in that: The second normally open contact of the main body heavy gas and the main body heavy gas protection tripping pressure plate connected in series on the main body heavy gas tripping starting branch, the second normally open contact of the load gas and the load gas protection tripping pressure plate connected in series on the load gas tripping starting branch, the second normally open contact of the pressure release and the pressure release protection tripping pressure plate connected in series on the pressure release tripping starting branch, and the second normally open contact of the ultra-high temperature and the ultra-high temperature protection tripping pressure plate connected in series on the ultra-high temperature tripping starting branch; The second normally open contact of the main body's heavy gas, the second normally open contact of the loaded gas, the second normally open contact of the pressure release, and the second normally open contact of the ultra-high temperature are all located in the non-electrical protection measurement and control device.

7. The main transformer non-electrical quantity protection control circuit according to claim 1 is characterized in that: The positive pole of the DC power supply of the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit is connected to one end of the normally open contact of the main transformer high-voltage side circuit breaker non-electrical protection tripping output relay, the other end of the normally open contact of the main transformer high-voltage side circuit breaker non-electrical protection tripping output relay is connected to one end of the high-voltage side circuit breaker non-electrical protection tripping pressure plate, the other end of the high-voltage side circuit breaker non-electrical protection tripping pressure plate is connected to one end of the tripping holding relay 1, the other end of the tripping holding relay 1 is connected to one end of the auxiliary normally open contact of the main transformer high-voltage side circuit breaker, the other end of the auxiliary normally open contact of the main transformer high-voltage side circuit breaker is connected to one end of the main transformer high-voltage side circuit breaker opening coil, and the other end of the main transformer high-voltage side circuit breaker opening coil is connected to the negative pole of the DC power supply; The positive pole of the DC power supply of the tripping circuit of the low-voltage side circuit breaker of the main transformer non-electrical protection is connected to one end of the normally open contact of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer, the other end of the normally open contact of the non-electrical protection tripping output relay of the low-voltage side circuit breaker of the main transformer is connected to one end of the non-electrical protection tripping pressure plate of the low-voltage side circuit breaker, the other end of the non-electrical protection tripping pressure plate of the low-voltage side circuit breaker is connected to one end of the trip holding relay 2, the other end of the trip holding relay 2 is connected to one end of the auxiliary normally open contact of the low-voltage side circuit breaker of the main transformer, the other end of the auxiliary normally open contact of the low-voltage side circuit breaker of the main transformer is connected to one end of the opening coil of the low-voltage side circuit breaker of the main transformer, and the other end of the opening coil of the low-voltage side circuit breaker of the main transformer is connected to the negative pole of the DC power supply.

8. The main transformer non-electrical quantity protection control circuit according to claim 7 is characterized in that: The self-holding contacts of the trip-holding relay 1 and the trip-holding relay 2 are respectively connected in parallel to the positive pole of the DC power supply and one end of the coil of the trip-holding relay; the self-holding contacts of the trip-holding relay 1 and the trip-holding relay 2 and their coils are all located inside the microcomputer protection measurement and control device.

9. The main transformer non-electrical quantity protection control circuit according to claim 7, characterized in that: The states of the normally open contacts of the non-electrical protection tripping output relay of the main transformer high-voltage side circuit breaker and the normally open contacts of the non-electrical protection tripping output relay of the main transformer low-voltage side circuit breaker are respectively controlled by their own non-electrical protection tripping output relays; the normally open contacts and coils of the non-electrical protection tripping output relay of the main transformer high-voltage side circuit breaker and the normally open contacts and coils of the non-electrical protection tripping output relay of the main transformer low-voltage side circuit breaker are both located inside the microcomputer protection measurement and control device.

10. The working method of the main transformer non-electrical quantity protection control circuit according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. When the main transformer has abnormal working or equipment defects, the relevant contacts of the non-electrical protection signals of the corresponding on-site non-electrical protection, such as high oil temperature, light gas on load, heavy gas on load, cold control power failure, light gas on the main body, heavy gas on the main body, and pressure release, will be closed, the DC power supply will connect the corresponding signal acquisition branch, the corresponding non-electrical protection relay coil will be energized, and the corresponding normally open contacts of the non-electrical protection relay will connect the main transformer non-electrical signal alarm circuit and the main transformer non-electrical protection trip start circuit respectively; S2. When any of the normally open contacts of non-electrical alarms such as high oil temperature, light gas on load, heavy gas on load, power failure of cold control, light gas on body, heavy gas on body, and pressure release is closed, the DC power supply will connect the corresponding non-electrical signal alarm circuit of the main transformer, and issue the corresponding non-electrical signal alarm, which will be transmitted to the background monitoring microcomputer through the communication interface of the microcomputer protection measurement and control device via the communication line, and an abnormal alarm message will be issued to prompt the on-duty personnel to pay attention and handle it; S3. When any of the tripping contacts of the main transformer body's heavy gas, load gas, pressure release, and over-high temperature is closed and connected, the DC power supply will connect the corresponding main transformer non-electrical protection tripping starting circuit through the corresponding non-electrical protection tripping pressure plate, and the main transformer non-electrical protection tripping output relay coil will be energized. The corresponding normally open contacts of the main transformer non-electrical protection tripping output relay can connect the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit and the main transformer non-electrical protection high-voltage side circuit breaker tripping circuit, and disconnect the circuit breakers on both the high and low voltage sides of the main transformer.

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