Secondary power supply circuit for single-circuit incoming line of flame-proof high-voltage combined power distribution device

Abstract

The utility model provides a secondary power supply circuit for a single-circuit incoming line of an explosion-proof type high-voltage combined power distribution device. The secondary power supply circuit comprises a high-voltage control transformer T1, a secondary side main switch S1, circuit breakers ZK0, ZK1, ZK2, ZK3, ZK4, ZK5 and ZK6, a dual-power switching device U1, an overvoltage relay GY and an undervoltage relay QY, the primary side of the high-voltage control transformer T1 is used for being connected with primary side high voltage; the secondary side of the high-voltage control transformer T1 comprises a main winding and an auxiliary winding; wherein the main winding is provided with a center tap; the first type of power utilization loop comprises a circuit breaker 1ZK, a door control switch S1 and a relay K1; the second type of power utilization loop comprises a circuit breaker 1-1ZK, a door control switch 1-S1 and a relay 1-K1; according to the utility model, the 220v voltage power supply of the secondary side can be ensured when the high voltage of the primary side is switched, and the 220v voltage power supply can be timely and automatically switched to the external power supply for 220v voltage power supply when the self-power supply is powered off in cooperation with the dual-power-supply switching device.

Description

Technical Field

[0001] The utility model relates to an electric circuit, in particular to a secondary power supply circuit for a single-circuit incoming line of an explosion-proof high-voltage combined power distribution device. Background Art

[0002] At present, the voltage level of explosion-proof high-voltage combined distribution devices is generally 10kV or 6kV. When the working environment voltage of the equipment is switched from 10kV to 6kV, the staff needs to replace the control transformer inside the equipment, 10kV / 220V to 6kV / 220V, which is not only time-consuming and labor-intensive, but also delays underground production in coal mines.

[0003] In addition, when the transformer of the coal mine's underground self-power supply fails, the secondary-side electrical equipment will lose power and will not be able to operate normally. Summary of the invention

[0004] In view of the deficiencies in the prior art, the embodiment of the utility model provides a secondary power supply circuit for a single-circuit incoming line of a flameproof high-voltage combined power distribution device, which can ensure the 220v voltage supply on the secondary side when the high voltage on the primary side is switched, and cooperate with a dual power supply switching device, when the self-power supply is cut off, it can automatically switch to the external power supply for 220v voltage supply in time, thereby ensuring the power safety of the secondary side electrical equipment. In order to achieve the above technical objectives, the technical solution adopted by the embodiment of the utility model is:

[0005] In the first aspect, the embodiment of the utility model provides a secondary power supply circuit for a single-circuit incoming line of a flameproof high-voltage combined power distribution device, including: a high-voltage control transformer T1, a secondary side main switch S1, circuit breakers ZK0, ZK1, ZK2, ZK3, ZK4, ZK5, ZK6, a dual power switching device U1, an overvoltage relay GY, and an undervoltage relay QY;

[0006] The primary side of the high-voltage control transformer T1 is used to connect the primary side high voltage;

[0007] The secondary side of the high-voltage control transformer T1 includes a main winding and an auxiliary winding; wherein the main winding is provided with an intermediate tap;

[0008] One end of the secondary side main winding of the high-voltage control transformer T1 is connected to one end of the first connection of the secondary side main switch S1, the other end of the first connection of the secondary side main switch S1 is connected to one end of the circuit breaker ZK0, the other end of the circuit breaker ZK0 is connected to one end of the normally open contact QY-1 of the undervoltage relay QY, the other end of the normally open contact QY-1 of the undervoltage relay QY is connected to one end of the normally closed contact GY-1 of the overvoltage relay GY, the other end of the normally closed contact GY-1 of the overvoltage relay GY is connected to one end of the first connection of the switch QF1 in the dual power switching device U1; the other end of the first connection of the switch QF1 in the dual power switching device U1 is connected to one end of the first connection of the circuit breaker ZK4 and one end of the first connection of the circuit breaker ZK5;

[0009] One end of the middle tap on the secondary side of the high-voltage control transformer T1 is connected to one end of the second link of the secondary side main switch S1, the other end of the second link of the secondary side main switch S1 is connected to one end of the circuit breaker ZK1, the other end of the circuit breaker ZK1 is connected to one end of the power supply end of the undervoltage relay QY, one end of the power supply end of the overvoltage relay GY and one end of the normally closed contact QY-2 of the undervoltage relay QY, the normally closed contact QY-2 of the undervoltage relay QY is connected to one end of the normally open contact GY-2 of the overvoltage relay GY, and the other end of the normally open contact GY-2 of the overvoltage relay GY is connected to one end of the first link of the switch QF1 in the dual power switching device U1;

[0010] The other end of the secondary side main winding of the high-voltage control transformer T1 is connected to one end of the third link of the secondary side main switch S1, the other end of the third link of the secondary side main switch S1 is connected to one end of the circuit breaker ZK2, the other end of the circuit breaker ZK2 is connected to the other end of the power supply end of the undervoltage relay QY, the other end of the power supply end of the overvoltage relay GY and one end of the second link of the switch QF1 in the dual power switching device U1; the other end of the second link of the switch QF1 in the dual power switching device U1 is connected to one end of the second link of the circuit breaker ZK4 and one end of the second link of the circuit breaker ZK5;

[0011] The other end of the first link and the other end of the second link of the circuit breaker ZK4 are connected to the first type of power circuit; the other end of the first link and the other end of the second link of the circuit breaker ZK5 are connected to the second type of power circuit;

[0012] One end of the secondary side auxiliary winding of the high voltage control transformer T1 is connected to one end of the fourth link of the secondary side main switch S1, the other end of the fourth link of the secondary side main switch S1 is connected to one end of the first link of the circuit breaker ZK3, the other end of the first link of the circuit breaker ZK3 is connected to one end of the detection end of the undervoltage relay QY and one end of the detection end of the overvoltage relay GY;

[0013] The other end of the secondary side auxiliary winding of the high voltage control transformer T1 is connected to one end of the fifth connection of the secondary side main switch S1, the other end of the fifth connection of the secondary side main switch S1 is connected to one end of the second connection of the circuit breaker ZK3, the other end of the second connection of the circuit breaker ZK3 is connected to the other end of the detection end of the undervoltage relay QY and the other end of the detection end of the overvoltage relay GY;

[0014] One end of the first connection and one end of the second connection of the circuit breaker ZK6 are used to connect to an external power supply, the other end of the first connection of the circuit breaker ZK6 is connected to one end of the first connection of the switch QF2 in the dual power switching device U1, and the other end of the second connection of the circuit breaker ZK6 is connected to one end of the second connection of the switch QF2 in the dual power switching device U1; the other end of the first connection of the switch QF2 in the dual power switching device U1 is connected to one end of the first connection of the circuit breaker ZK4 and one end of the first connection of the circuit breaker ZK5; the other end of the second connection of the switch QF2 in the dual power switching device U1 is connected to one end of the second connection of the circuit breaker ZK4 and one end of the second connection of the circuit breaker ZK5;

[0015] The overvoltage relay GY and undervoltage relay QY are configured so that when the primary side of the high-voltage control transformer T1 is connected to the first high voltage, the overvoltage relay GY is energized but the undervoltage relay QY is not energized, and when the primary side of the high-voltage control transformer T1 is connected to the second high voltage, the overvoltage relay GY is not energized but the undervoltage relay QY is energized; the first high voltage is greater than the second voltage.

[0016] Furthermore, the first type of power circuit includes: a circuit breaker 1ZK, a gate switch S1, and a relay K1;

[0017] One end of the first group of circuit breaker 1ZK is connected to the other end of the first group of circuit breaker ZK4, and one end of the second group of circuit breaker 1ZK is connected to the other end of the second group of circuit breaker ZK4; the other end of the first group of circuit breaker 1ZK is connected to one end of the gate-controlled switch S1 and one end of the first group of normally open contact K1-1 of relay K1; the other end of the second group of circuit breaker 1ZK is connected to one end of the coil of relay K1 and one end of the second group of normally open contact K1-1 of relay K1; the other end of the coil of relay K1 is connected to the other end of the gate-controlled switch S1; the other end of the first group of normally open contact K1-1 of relay K1 and the other end of the second group of normally open contact K1-1 are used to connect to comprehensive protection electrical equipment.

[0018] Furthermore, the second type of power circuit includes: a circuit breaker 1-1ZK, a gate switch 1-S1, and a relay 1-K1;

[0019] One end of the first group of circuit breaker 1-1ZK is connected to the other end of the first group of circuit breaker ZK5, and one end of the second group of circuit breaker 1-1ZK is connected to the other end of the second group of circuit breaker ZK5; the other end of the first group of circuit breaker 1-1ZK is connected to one end of gate switch 1-S1 and one end of the first group of normally open contact 1-K1-1 of relay 1-K1; the other end of the second group of circuit breaker 1-1ZK is connected to one end of relay 1-K1 coil and one end of the second group of normally open contact 1-K1-1 of relay 1-K1; the other end of relay 1-K1 coil is connected to the other end of gate switch 1-S1; the other end of the first group of normally open contact 1-K1-1 of relay 1-K1 and the other end of the second group of normally open contact 1-K1-1 are used to connect lighting or heating equipment.

[0020] The beneficial effects of the technical solution provided by the embodiment of the utility model are: when the high voltage on the primary side is switched, the power supply on the secondary side can be automatically switched to ensure the 220V voltage power supply on the secondary side; and when the primary side is powered off, it can automatically switch to the external power supply to achieve uninterrupted power supply to the secondary side electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the circuit in the embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0023] like Figure 1 As shown, a secondary power supply circuit for a single-circuit incoming line of a flameproof high-voltage combined power distribution device proposed in an embodiment of the utility model includes: a high-voltage control transformer T1, a secondary side main switch S1, circuit breakers ZK0, ZK1, ZK2, ZK3, ZK4, ZK5, ZK6, a dual power supply switching device U1, an overvoltage relay GY, and an undervoltage relay QY;

[0024] The primary side of the high-voltage control transformer T1 is used to connect the primary high voltage; in this embodiment, the primary high voltage can be switched between 10kV and 6kv; the high-voltage control transformer T1 is a self-powered transformer;

[0025] The secondary side of the high-voltage control transformer T1 includes a main winding and an auxiliary winding; wherein the main winding is provided with an intermediate tap; the main winding can output a 220v voltage when the primary side high voltage is 6kv, and the intermediate tap can output a 220v voltage when the primary side high voltage is 10kv;

[0026] One end of the secondary side main winding of the high-voltage control transformer T1 is connected to one end of the first connection of the secondary side main switch S1, the other end of the first connection of the secondary side main switch S1 is connected to one end of the circuit breaker ZK0, the other end of the circuit breaker ZK0 is connected to one end of the normally open contact QY-1 of the undervoltage relay QY, the other end of the normally open contact QY-1 of the undervoltage relay QY is connected to one end of the normally closed contact GY-1 of the overvoltage relay GY, the other end of the normally closed contact GY-1 of the overvoltage relay GY is connected to one end of the first connection of the switch QF1 in the dual power switching device U1; the other end of the first connection of the switch QF1 in the dual power switching device U1 is connected to one end of the first connection of the circuit breaker ZK4 and one end of the first connection of the circuit breaker ZK5;

[0027] One end of the middle tap on the secondary side of the high-voltage control transformer T1 is connected to one end of the second link of the secondary side main switch S1, the other end of the second link of the secondary side main switch S1 is connected to one end of the circuit breaker ZK1, the other end of the circuit breaker ZK1 is connected to one end of the power supply end of the undervoltage relay QY, one end of the power supply end of the overvoltage relay GY and one end of the normally closed contact QY-2 of the undervoltage relay QY, the normally closed contact QY-2 of the undervoltage relay QY is connected to one end of the normally open contact GY-2 of the overvoltage relay GY, and the other end of the normally open contact GY-2 of the overvoltage relay GY is connected to one end of the first link of the switch QF1 in the dual power switching device U1;

[0028] The other end of the secondary side main winding of the high-voltage control transformer T1 is connected to one end of the third link of the secondary side main switch S1, the other end of the third link of the secondary side main switch S1 is connected to one end of the circuit breaker ZK2, the other end of the circuit breaker ZK2 is connected to the other end of the power supply end of the undervoltage relay QY, the other end of the power supply end of the overvoltage relay GY and one end of the second link of the switch QF1 in the dual power switching device U1; the other end of the second link of the switch QF1 in the dual power switching device U1 is connected to one end of the second link of the circuit breaker ZK4 and one end of the second link of the circuit breaker ZK5;

[0029] The other end of the first connection of the circuit breaker ZK4 and the other end of the second connection are connected to the first type of power circuit; the other end of the first connection of the circuit breaker ZK5 and the other end of the second connection are connected to the second type of power circuit; in this embodiment, the first type of power circuit is a comprehensive protection circuit, and the second type of power circuit is a heating or lighting circuit; the comprehensive protection circuit is used to connect electric chassis, electric grounding knife, LCD screen and other electric equipment; the lighting circuit is used to connect the lighting electric equipment in the cabinet, and the heating circuit is used to connect the heater electric equipment in the cabinet;

[0030] One end of the secondary side auxiliary winding of the high voltage control transformer T1 is connected to one end of the fourth link of the secondary side main switch S1, the other end of the fourth link of the secondary side main switch S1 is connected to one end of the first link of the circuit breaker ZK3, the other end of the first link of the circuit breaker ZK3 is connected to one end of the detection end of the undervoltage relay QY and one end of the detection end of the overvoltage relay GY;

[0031] The other end of the secondary side auxiliary winding of the high voltage control transformer T1 is connected to one end of the fifth connection of the secondary side main switch S1, the other end of the fifth connection of the secondary side main switch S1 is connected to one end of the second connection of the circuit breaker ZK3, the other end of the second connection of the circuit breaker ZK3 is connected to the other end of the detection end of the undervoltage relay QY and the other end of the detection end of the overvoltage relay GY;

[0032] One end of the first connection and one end of the second connection of the circuit breaker ZK6 are used to connect to an external power supply, the other end of the first connection of the circuit breaker ZK6 is connected to one end of the first connection of the switch QF2 in the dual power switching device U1, and the other end of the second connection of the circuit breaker ZK6 is connected to one end of the second connection of the switch QF2 in the dual power switching device U1; the other end of the first connection of the switch QF2 in the dual power switching device U1 is connected to one end of the first connection of the circuit breaker ZK4 and one end of the first connection of the circuit breaker ZK5; the other end of the second connection of the switch QF2 in the dual power switching device U1 is connected to one end of the second connection of the circuit breaker ZK4 and one end of the second connection of the circuit breaker ZK5;

[0033] The overvoltage relay GY and the undervoltage relay QY are configured such that when the primary side of the high-voltage control transformer T1 is connected to the first high voltage, the overvoltage relay GY is energized but the undervoltage relay QY is not energized, and when the primary side of the high-voltage control transformer T1 is connected to the second high voltage, the overvoltage relay GY is not energized but the undervoltage relay QY is energized; the first high voltage is greater than the second voltage; in the present embodiment, the first high voltage is 10 kV and the second high voltage is 6 kV.

[0034] The working principle of this embodiment is as follows: first, close the secondary side main switch S1, circuit breakers ZK0, ZK1, ZK2, ZK3, ZK4, ZK5, and ZK6; when the primary side high voltage is 10kv, the overvoltage relay GY is energized, at which time the normally open contact GY-2 of the overvoltage relay GY is closed, and the normally closed contact GY-1 is disconnected, and the middle tap of the secondary side of the high-voltage control transformer T1 outputs a 220v voltage to the dual power switching device U1; the dual power switching device U1 can be configured to have the default switch QF1 closed, and when it is detected that the switch QF1 loses power, the switch QF2 is automatically closed and the switch QF1 is disconnected; the dual power switching device U1 is a mature product available on the market; at this time, the switch QF1 of the dual power switching device U1 supplies power to the circuit breakers ZK4 and ZK5, and the electrical equipment connected to the first type of power circuit and the second type of power circuit is powered on and works;

[0035] When the primary side high voltage is switched from 10kv to 6kv, the undervoltage relay QY is energized, at which time the normally open contact QY-1 of the undervoltage relay QY is closed, and the normally closed contact QY-2 is disconnected, and the main winding of the high-voltage control transformer T1 outputs 220v voltage to the dual power switching device U1; at this time, the switch QF1 of the dual power switching device U1 supplies power to the circuit breakers ZK4 and ZK5, and the electrical equipment connected to the first and second power circuits is powered on;

[0036] When the self-powered power supply needs to be repaired or the high-voltage control transformer T1 needs to be disconnected, the switch QF1 in the dual power switching device U1 loses power and the switch QF2 is automatically closed. At this time, the 220V voltage is output to the dual power switching device U1 through the external power supply;

[0037] In this embodiment, the first type of power circuit includes: circuit breaker 1ZK, gate switch S1, relay K1;

[0038] One end of the first link of circuit breaker 1ZK is connected to the other end of the first link of circuit breaker ZK4, and one end of the second link of circuit breaker 1ZK is connected to the other end of the second link of circuit breaker ZK4; the other end of the first link of circuit breaker 1ZK is connected to one end of gate-controlled switch S1 and one end of the first link of normally open contact K1-1 of relay K1; the other end of the second link of circuit breaker 1ZK is connected to one end of relay K1 coil and one end of the second link of normally open contact K1-1 of relay K1; the other end of relay K1 coil is connected to the other end of gate-controlled switch S1; the other end of the first link of normally open contact K1-1 of relay K1 and the other end of the second link of normally open contact K1-1 are used to connect to comprehensive protection electrical equipment;

[0039] In this embodiment, the second type of power circuit includes: a circuit breaker 1-1ZK, a gate switch 1-S1, and a relay 1-K1;

[0040] One end of the first group of circuit breaker 1-1ZK is connected to the other end of the first group of circuit breaker ZK5, and one end of the second group of circuit breaker 1-1ZK is connected to the other end of the second group of circuit breaker ZK5; the other end of the first group of circuit breaker 1-1ZK is connected to one end of gate switch 1-S1 and one end of the first group of normally open contact 1-K1-1 of relay 1-K1; the other end of the second group of circuit breaker 1-1ZK is connected to one end of relay 1-K1 coil and one end of the second group of normally open contact 1-K1-1 of relay 1-K1; the other end of relay 1-K1 coil is connected to the other end of gate switch 1-S1; the other end of the first group of normally open contact 1-K1-1 of relay 1-K1 and the other end of the second group of normally open contact 1-K1-1 are used to connect lighting or heating equipment.

[0041] The working principles of the first and second type of power circuits are the same. Taking the first type of power circuit as an example, close the circuit breaker 1ZK. When the cabinet door is closed, the door-controlled switch S1 is closed, the relay K1 coil is energized, the first and second links of the normally closed contacts K1-1 of the relay K1 are closed, and the electrical equipment is energized.

[0042] Several first-class power circuits and several second-class power circuits can be configured.

[0043] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A secondary power supply circuit for a single-circuit incoming line of a flameproof high-voltage combined power distribution device, characterized in that: include: High-voltage control transformer T1, secondary side main switch S1, circuit breakers ZK0, ZK1, ZK2, ZK3, ZK4, ZK5, ZK6, dual power switching device U1, overvoltage relay GY, undervoltage relay QY; The primary side of the high-voltage control transformer T1 is used to connect to the primary side high voltage; The secondary side of the high-voltage control transformer T1 includes a main winding and an auxiliary winding; wherein the main winding is provided with an intermediate tap; One end of the secondary-side main winding of the high-voltage control transformer T1 is connected to one end of the first connection of the secondary-side main switch S1, the other end of the first connection of the secondary-side main switch S1 is connected to one end of the circuit breaker ZK0, the other end of the circuit breaker ZK0 is connected to one end of the normally-open contact QY-1 of the undervoltage relay QY, the other end of the normally-open contact QY-1 of the undervoltage relay QY is connected to one end of the normally-closed contact GY-1 of the overvoltage relay GY, the other end of the normally-closed contact GY-1 of the overvoltage relay GY is connected to one end of the first connection of the switch QF1 in the dual-power switching device U1; the other end of the first connection of the switch QF1 in the dual-power switching device U1 is connected to one end of the first connection of the circuit breaker ZK4 and one end of the first connection of the circuit breaker ZK5; One end of the center tap on the secondary side of the high-voltage control transformer T1 is connected to one end of the second leg of the secondary-side main switch S1, the other end of the second leg of the secondary-side main switch S1 is connected to one end of the circuit breaker ZK1, the other end of the circuit breaker ZK1 is connected to one end of the power supply terminal of the undervoltage relay QY, one end of the power supply terminal of the overvoltage relay GY, and one end of the normally closed contact QY-2 of the undervoltage relay QY, the normally closed contact QY-2 of the undervoltage relay QY is connected to one end of the normally open contact GY-2 of the overvoltage relay GY, and the other end of the normally open contact GY-2 of the overvoltage relay GY is connected to one end of the first leg of the switch QF1 in the dual power switching device U1; The other end of the secondary side main winding of the high-voltage control transformer T1 is connected to one end of the third branch of the secondary side main switch S1, the other end of the third branch of the secondary side main switch S1 is connected to one end of the circuit breaker ZK2, the other end of the circuit breaker ZK2 is connected to the other end of the power supply terminal of the undervoltage relay QY, the other end of the power supply terminal of the overvoltage relay GY, and one end of the second branch of the switch QF1 in the dual power switching device U1; the other end of the second branch of the switch QF1 in the dual power switching device U1 is connected to one end of the second branch of the circuit breaker ZK4 and one end of the second branch of the circuit breaker ZK5; The other end of the first and second ends of the circuit breaker ZK4 are connected to the first type of power circuit; the other end of the first and second ends of the circuit breaker ZK5 are connected to the second type of power circuit; One end of the secondary-side auxiliary winding of the high-voltage control transformer T1 is connected to one end of the fourth leg of the secondary-side main switch S1, the other end of the fourth leg of the secondary-side main switch S1 is connected to one end of the first leg of the circuit breaker ZK3, the other end of the first leg of the circuit breaker ZK3 is connected to one end of the detection terminal of the undervoltage relay QY and one end of the detection terminal of the overvoltage relay GY; The other end of the secondary-side auxiliary winding of the high-voltage control transformer T1 is connected to one end of the fifth leg of the secondary-side main switch S1. The other end of the fifth leg of the secondary-side main switch S1 is connected to one end of the second leg of the circuit breaker ZK3. The other end of the second leg of the circuit breaker ZK3 is connected to the other end of the detection terminal of the undervoltage relay QY and the other end of the detection terminal of the overvoltage relay GY. One end of the first and second connections of circuit breaker ZK6 are used to connect to an external power supply. The other end of the first connection of circuit breaker ZK6 is connected to one end of the first connection of switch QF2 in the dual power switching device U1, and the other end of the second connection of circuit breaker ZK6 is connected to one end of the second connection of switch QF2 in the dual power switching device U1. The other end of the first connection of switch QF2 in the dual power switching device U1 is connected to one end of the first connection of circuit breaker ZK4 and one end of the first connection of circuit breaker ZK5. The other end of the second connection of switch QF2 in the dual power switching device U1 is connected to one end of the second connection of circuit breaker ZK4 and one end of the second connection of circuit breaker ZK5. The overvoltage relay GY and undervoltage relay QY are configured so that when the primary side of the high-voltage control transformer T1 is connected to a first high voltage, the overvoltage relay GY is energized but the undervoltage relay QY is not energized; and when the primary side of the high-voltage control transformer T1 is connected to a second high voltage, the overvoltage relay GY is not energized but the undervoltage relay QY is energized; the first high voltage is greater than the second voltage.

2. The secondary power supply circuit for a single-circuit incoming line of a flameproof high-voltage combined power distribution device according to claim 1, characterized in that: The first type of power circuit includes: circuit breaker 1ZK, gate switch S1, relay K1; One end of the first group of circuit breaker 1ZK is connected to the other end of the first group of circuit breaker ZK4, and one end of the second group of circuit breaker 1ZK is connected to the other end of the second group of circuit breaker ZK4; the other end of the first group of circuit breaker 1ZK is connected to one end of the gate-controlled switch S1 and one end of the first group of normally open contact K1-1 of relay K1; the other end of the second group of circuit breaker 1ZK is connected to one end of the coil of relay K1 and one end of the second group of normally open contact K1-1 of relay K1; the other end of the coil of relay K1 is connected to the other end of the gate-controlled switch S1; the other end of the first group of normally open contact K1-1 of relay K1 and the other end of the second group of normally open contact K1-1 are used to connect to comprehensive protection electrical equipment.

3. The secondary power supply circuit for a single-circuit incoming line of a flameproof high-voltage combined power distribution device according to claim 1, characterized in that: The second type of power circuit includes: circuit breaker 1-1ZK, door switch 1-S1, relay 1-K1; One end of the first group of circuit breaker 1-1ZK is connected to the other end of the first group of circuit breaker ZK5, and one end of the second group of circuit breaker 1-1ZK is connected to the other end of the second group of circuit breaker ZK5; the other end of the first group of circuit breaker 1-1ZK is connected to one end of the door-controlled switch 1-S1 and one end of the first group of normally open contact 1-K1-1 of relay 1-K1; the other end of the second group of circuit breaker 1-1ZK is connected to one end of the coil of relay 1-K1 and one end of the second group of normally open contact 1-K1-1 of relay 1-K1; the other end of the coil of relay 1-K1 is connected to the other end of the door-controlled switch 1-S1; the other end of the first group of normally open contact 1-K1-1 of relay 1-K1 and the other end of the second group of normally open contact 1-K1-1 are used to connect to lighting or heating equipment.

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