CN212012252U - A switching circuit and power distribution system for mains power generation - Google Patents

Abstract

The application belongs to the technical field of electric power supply systems, and in particular relates to a mains power generation power switching circuit and a power distribution system, which control the connection state between the mains power supply and the load through a first circuit breaker; The output mains voltage is detected, and a mains detection signal is generated; the second circuit breaker controls the connection state between the power generation source and the load according to the mains detection signal; the load is at most connected to the mains power supply and the power generation power source. A power supply connection; realizes automatic, fast and effective switching between the mains power supply and the auxiliary power supply power supply. The switching time of the mains power supply and the power generation power supply is short and the efficiency is high, which reduces the economic loss caused by the long power switching time and saves money. cost, and improve the practicability of the mains power generation power switching circuit.

Description

A switching circuit and power distribution system for mains power generation

technical field

The application belongs to the technical field of electric power supply systems, and in particular relates to a mains power generation power switching circuit and a power distribution system.

Background technique

At present, in general factories and residential commercial power supply and distribution systems, in order to ensure the uninterrupted power supply of important loads (such as fire elevators, fire pumps, emergency lighting and other loads), the mains and power generation dual power supply methods are often used; the mains refers to the transformer. Power supply, power generation refers to the power supply of diesel generators; both the mains and the power generation supply power to the loads on the same section of the bus. Under normal circumstances, the mains supply power, but when the mains fails, it needs to be switched to the power generation equipment, which is powered by the power generation equipment. Power generation and power supply to reduce the impact of power outages; when the mains power supply is restored again, it is necessary to switch back to the mains power supply. The traditional switch between mains and power generation uses manual switching. The power distribution room needs to be set up to be on duty, which will result in labor costs, and manual switching will cause the power outage interval to be too long, resulting in certain economic losses.

Therefore, in the traditional technical solution, there are problems such as long switching time between manual switching of mains power and power generation, resulting in a long power outage interval, low power switching efficiency and high cost.

Utility model content

The purpose of this application is to provide a mains power generation power switching circuit and power distribution system, which aims to solve the traditional manual switching power supply switching time is long, resulting in a long power outage interval, low power switching efficiency, and high cost.

The first aspect of the embodiments of the present application provides a mains power generation power switching circuit, which is respectively connected to the mains power source, the power generation power source and the load, and the mains power generation power supply switching circuit includes:

a first circuit breaker, connected to the mains power supply and the load respectively, and configured to control the connection state between the mains power supply and the load;

a detection relay, the coil of the detection relay is connected to the mains power supply, and is configured to detect the mains voltage output by the mains power supply, and generate a mains detection signal;

The second circuit breaker is respectively connected to the first circuit breaker, the power generation source, the load and the detection relay, and is configured to control the connection between the generation power source and the load according to the mains detection signal. The connection state is controlled; wherein, the load is connected to at most one of the commercial power source and the power generation source.

In one embodiment, the mains power generation power switching circuit further includes:

a first time relay, which is respectively connected to the normally closed auxiliary contacts of the mains power supply, the first circuit breaker and the second circuit breaker, and is configured to delay the connection of the first circuit breaker according to the mains voltage the closing coil of the device;

The second time relay is respectively connected to the power generation source, the second circuit breaker, the normally closed auxiliary contact of the first circuit breaker and the normally closed contact of the detection relay, and is configured to delay according to the generation voltage The closing coil of the second circuit breaker is connected.

In one embodiment, the mains power generation power switching circuit further includes:

a mode changeover switch, which is respectively connected to the commercial power supply, the power generation power supply, the first time relay and the second time relay, and is configured to switch the power distribution mode according to the first input signal;

A gate control assembly, respectively associated with the mode changeover switch, the normally closed auxiliary contact of the second circuit breaker, the first circuit breaker, the normally closed auxiliary contact of the first circuit breaker, and the second circuit breaker The device is connected and configured to connect the mains power supply or the power generation power supply according to the second input signal in the manual mode.

In one embodiment, the mains power generation power switching circuit further includes:

The first indication circuit is respectively connected to the mains power supply and the first circuit breaker, and is configured to indicate the state of the first circuit breaker according to the mains voltage.

In one embodiment, the mains power generation power switching circuit further includes:

A second indication circuit is connected to the power generation source and the second circuit breaker respectively, and is configured to indicate the state of the second circuit breaker according to the generation voltage.

In one embodiment, the mains power generation power switching circuit further includes:

a first protection circuit, which is respectively connected to the mains power supply, the detection relay and the first circuit breaker, and is configured to perform overcurrent protection on the mains voltage;

A second protection circuit is connected to the power generation source and the second circuit breaker respectively, and is configured to perform overcurrent protection on the power generation voltage.

In one of the embodiments, the detection relay includes: a first intermediate relay and a second intermediate relay; wherein,

The coil of the first intermediate relay and the coil of the second intermediate relay are connected to the commercial power supply, and the normally closed contact of the first intermediate relay is connected to the normally closed contact of the second intermediate relay, The normally closed contact of the first intermediate relay is also connected to the power generation source, and the normally closed contact of the second intermediate relay is also connected to the second circuit breaker.

In one embodiment, a mechanical interlock and an electrical interlock are further provided between the first circuit breaker and the second circuit breaker.

A first aspect of the embodiments of the present application provides a power distribution system, the power distribution system includes: a commercial power source, a power generation power source, a load, and the commercial power generation power source switching circuit described in any one of the above.

The mains power generation switching circuit of the embodiment of the present invention controls the connection state between the mains power supply and the load through the first circuit breaker; the detection relay detects the mains voltage output by the mains power supply, and generates a mains detection signal; the second circuit breaker controls the connection state between the power generation source and the load according to the mains detection signal; the load is connected to at most one of the mains power source and the power generation power source; realizes automatic, fast and effective switching of mains power The power supply and the power generation power supply are used to supply power to the load. The power supply switching time is short and the efficiency is high, which reduces the economic loss caused by the long power switching time, saves the cost, and improves the practicability of the mains power generation power switching circuit.

Description of drawings

FIG. 1 is an exemplary circuit schematic diagram of a mains power generation power switching circuit provided by an embodiment of the present application;

2 is a schematic structural diagram of mechanical interlocking and electrical interlocking between a first circuit breaker and a second circuit breaker in a commercial power generation power switching circuit provided by an embodiment of the present application;

FIG. 3 is another exemplary circuit schematic diagram of a mains power generation power switching circuit provided by an embodiment of the present application;

FIG. 4 is another exemplary circuit schematic diagram of a mains power generation power switching circuit provided by an embodiment of the present application.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

It is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top" , "bottom", "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the indicated device. Or elements must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present application, "plurality" means two or more, unless otherwise expressly and specifically defined.

Fig. 1 shows a schematic structural diagram of ... provided by a preferred embodiment of the present application (Fig. 1 shows the first embodiment of the present application). For the convenience of description, only the parts related to this embodiment are shown. as follows:

The first aspect of the embodiments of the present application provides a mains power generation power switching circuit, which is respectively connected to the mains power source, the power generation power source and the load. The mains power generation power source switching circuit includes: a first circuit breaker S-QF, a second circuit breaker F-QF and detection relay KA.

The first circuit breaker S-QF is connected to the mains power supply and the load respectively, and is configured to control the connection state between the mains power supply and the load; the detection relay KA, the coil of the detection relay KA is connected to the mains power supply, and is configured as The mains voltage output by the mains power supply is detected, and the mains detection signal is generated; the second circuit breaker F-QF is respectively connected with the first circuit breaker S-QF, the power generation source, the load and the detection relay KA, and is configured according to the The mains detection signal controls the connection state between the power generation source and the load; wherein the load is connected to at most one of the mains power source and the power generation source.

In a specific implementation, the mains power generation power switching circuit is arranged in the low-voltage power distribution cabinet. Optionally, the mains power supply provides the mains voltage; the power generation power is a diesel generator power supply, which provides the power generation voltage. The transformer converts the voltage of the mains output by the mains power supply and outputs the mains voltage on the low-voltage side of the transformer, and the incoming end of the first circuit breaker S-QF is connected to the mains voltage. The incoming line end of the second circuit breaker F-QF is connected to the generating voltage output by the generating power supply. The outlet end of the first circuit breaker S-QF and the outlet end of the second circuit breaker F-QF are connected to the load to supply power to the load.

Further, please refer to Fig. 2, a mechanical interlock and an electrical interlock are arranged between the first circuit breaker S-QF and the second circuit breaker F-QF, so as to ensure that only one of the two circuit breakers is connected to prevent the mains and The generators generate electricity and run in parallel. Among them, 1TAa~c and 2TAa~c are current transformers, which are used to detect the corresponding currents of the mains power supply and the power generation power supply, and feed them back to the upper terminal equipment.

When the mains is powered, the coil of the detection relay KA is energized, so that the normally closed contact of the detection relay KA is disconnected, and the closing coil X of the first circuit breaker S-QF is turned on at the same time, so that the first circuit breaker S-QF Closing, the normally closed auxiliary contact of the first circuit breaker S-QF is disconnected, and the generator power is turned off by disconnecting the normally closed contact of the detection relay KA and disconnecting the normally closed auxiliary contact of the first circuit breaker S-QF The connection with the second circuit breaker F-QF, thereby cutting off the automatic closing control circuit of the second circuit breaker F-QF. At this time, the mains supply power to the load, and the generator power supply does not provide the generation voltage; when the mains fails, the power is cut off. When the undervoltage release of the first circuit breaker S-QF acts to open the first circuit breaker S-QF, the normally closed auxiliary contact of the first circuit breaker S-QF is reset and closed, so that the diesel generator starts to generate electricity to generate electricity. Provide the power generation voltage, and at the same time detect the loss of power of the coil of the relay KA, the normally closed contact of the detection relay KA is reset and closed, the closing coil X of the second circuit breaker F-QF is turned on, and the second circuit breaker F-QF is closed. When the mains power is restored, the coil of the detection relay KA is re-energized, the normally closed contact of the detection relay KA is disconnected, and the undervoltage release of the second circuit breaker F-QF operates Open the second circuit breaker F-QF, reset and close the normally closed auxiliary contact of the second circuit breaker F-QF, turn on the closing coil X of the first circuit breaker S-QF, and the first circuit breaker S-QF Close the switch and restore the power supply to the load from the mains. Optionally, the normally closed auxiliary contact of the first circuit breaker S-QF is disconnected, and the feedback control of the diesel generator stops, and stops generating and outputting the power generation voltage.

The embodiment of the present application can automatically, quickly and effectively switch the mains power supply and the auxiliary diesel generator power supply, the power switching time is short, the efficiency is high, the economic loss caused by the long power switching time is reduced, and the relay is used instead of the expensive controller. The switching control of the power supply is carried out, the cost is reduced, and the practicability of the switching circuit of the commercial power generation power supply is improved.

Referring to FIG. 3 , in one embodiment, the mains power generation power switching circuit further includes: a first time relay 1KT and a second time relay 2KT.

The first time relay 1KT is connected to the mains power supply, the normally closed auxiliary contacts of the first circuit breaker S-QF and the second circuit breaker F-QF, and is configured to connect the first circuit breaker S- The closing coil of QF; the second time relay 2KT is respectively connected with the generator power supply, the second circuit breaker F-QF, the normally closed auxiliary contact of the first circuit breaker S-QF and the normally closed contact of the detection relay KA. In order to delay the connection of the closing coil of the second circuit breaker F-QF according to the generation voltage.

When the mains power supply, the coil of the first time relay 1KT is energized, and the normally open contact of the first time relay 1KT is closed after a delay. The closing coil X of S-QF makes the first circuit breaker S-QF close, the normally closed auxiliary contact of the first circuit breaker S-QF is disconnected, and the mains voltage is delayed to the load, and the relay KA is detected at the same time. The coil of the second time relay 2KT is energized, so that the normally closed contact of the detection relay KA is disconnected, and the connection between the power generation source and the coil of the second time relay 2KT is disconnected. The normally open contact remains disconnected, thereby disconnecting the connection between the power generation source and the second circuit breaker F-QF, and cutting off the automatic closing control circuit of the second circuit breaker F-QF. At this time, the mains supply power to the load, The generator power supply does not provide the generator voltage; when the mains fails, the undervoltage release of the first circuit breaker S-QF acts to open the first circuit breaker S-QF, and the normally closed auxiliary of the first circuit breaker S-QF The contact is reset and closed, so that the diesel generator starts power generation to provide the power generation voltage, and at the same time, the coil of the relay KA is detected to be de-energized, and the normally closed contact of the detection relay KA is reset and closed, and the power generation voltage is connected to the second time relay 2KT, so that the second time The coil of the relay 2KT is energized, and the normally open contact of the second time relay 2KT is closed after a delay. The second circuit breaker F-QF is closed, and the delay turns on the power generation voltage to the load. At this time, the diesel generator supplies power to the load; and when the mains power is restored, the coil of the detection relay KA is re-energized, and the detection relay KA is normally closed. The contact is disconnected, the undervoltage release of the second circuit breaker F-QF acts to open the second circuit breaker F-QF, the normally closed auxiliary contact of the second circuit breaker F-QF is reset and closed, and at the same time the first circuit breaker F-QF is closed. The coil of the time relay 1KT is energized, the normally open contact of the first time relay 1KT is delayed and closed, the closing coil X of the first circuit breaker S-QF is turned on, the first circuit breaker S-QF is closed, and the recovery is due to Mains supply power to the load; realize reliable and effective switching of power supply, and improve the safety and reliability of the mains power generation switching circuit. Optionally, the normally closed auxiliary contact of the first circuit breaker S-QF is disconnected, and the feedback controls the diesel generator to stop and stop supplying the generating voltage.

In one of the embodiments, the mains power generation power switching circuit further includes: a mode changeover switch SA and a gate control assembly.

The mode changeover switch SA is respectively connected with the commercial power supply, the power generation power supply, the first time relay 1KT and the second time relay 2KT, and is configured to switch the power distribution mode according to the first input signal; the gate control component is respectively connected with the mode changeover switch SA , the normally closed auxiliary contacts of the second circuit breaker F-QF, the first circuit breaker S-QF, the normally closed auxiliary contacts of the first circuit breaker S-QF, and the second circuit breaker F-QF are connected, configured according to the first circuit breaker S-QF. The two input signals are connected to the mains power supply or the power generation power supply.

In a specific implementation, the user may input the first input signal by operating a switch, a key switch, or a touch screen input to switch the power distribution mode. Specifically, referring to FIG. 3 , the user generates a corresponding first input signal by operating the mode switching switch SA to switch the power supply and distribution system to manual or automatic or stop mode. The gate control assembly is arranged on the low-voltage cabinet door, wherein the gate control assembly includes the closing button 1SBC of the first circuit breaker S-QF, the opening button 1SBS of the first circuit breaker S-QF, and the closing button of the second circuit breaker F-QF. The brake button 2SBC and the opening button 2SBS of the second circuit breaker F-QF. In the manual mode, the user generates a second input signal by operating the gate control component to control the connection of the mains power supply or the power generation power supply. The opening and closing buttons corresponding to the first circuit breaker S-QF and the second circuit breaker F-QF on the upper side respectively control the opening and closing of the first circuit breaker S-QF and the second circuit breaker F-QF in sequence, In this way, the switch between the mains power supply and the power generation power supply is realized. When the mode switch SA is set to the "automatic" position, the first circuit breaker S-QF, the second circuit breaker F-QF, the detection relay KA, the first time relay 1KT and the second time relay 2KT are used to realize the Electricity detection, and shutting off the power generation power according to the detection of connecting to the mains, and supplying power to the load by the mains; starting the power generation according to the detection of not being connected to the mains, and generating electricity from the diesel generator to supply power to the load, realizing automatic Switch between utility power and power generation to supply power to the load.

In one of the embodiments, the mains power generation power switching circuit further includes: a first indication circuit 11 .

The first indication circuit 11 is connected to the mains power supply and the first circuit breaker, and is configured to indicate the state of the first circuit breaker S-QF according to the mains voltage.

In real-time, see FIG. 4, the first indication circuit 11 includes an intermediate relay 1KA3, a first indicator light 1HG and a second indicator light 1HR; wherein, the first end of the coil of the intermediate relay 1KA3 is connected to the mains voltage, and the intermediate relay The second end of the coil of 1KA3 is connected to the first circuit breaker S-QF, the normally closed contact of the intermediate relay 1KA3 is connected to the second end of the first indicator light 1HG and the first circuit breaker S-QF, and the normally closed contact of the intermediate relay 1KA3 is connected to the first circuit breaker S-QF. The open contact is connected to the second end of the second indicator light 1HR and the first circuit breaker S-QF, and the first end of the first indicator light 1HG and the first end of the second indicator light 1HR are connected to the mains voltage together. When connected to the mains, the coil of the intermediate relay 1KA3 is energized, the normally closed contact of the intermediate relay 1KA3 is disconnected, the normally open contact of the intermediate relay 1KA3 is closed, the first indicator light 1HG is off, and the second indicator light 1HR is on. , to indicate the normal closing working state of the first circuit breaker S-QF; when the mains is not connected or the mains power supply fails or the first circuit breaker S-QF fails to connect to the mains, the coil of the intermediate relay 1KA3 No power supply, the normally closed contact of the intermediate relay 1KA3 remains closed, the normally open contact of the intermediate relay 1KA3 remains open, the first indicator light 1HG is on, and the second indicator light 1HR is off. The opening working status is indicated.

In one of the embodiments, the mains power generation power switching circuit further includes: a second indication circuit 15 .

The second indication circuit 15 is connected to the power generation source and the second circuit breaker F-QF, and is configured to indicate the state of the second circuit breaker F-QF according to the generation voltage.

In real time, referring to FIG. 4, the second indication circuit 15 includes an intermediate relay 2KA1, a third indicator light 2HG and a fourth indicator light 2HR; wherein, the first end of the coil of the intermediate relay 2KA1 is connected to the power generation voltage, and the intermediate relay 2KA1 The second end of the coil is connected to the second circuit breaker F-QF, the normally closed contact of the intermediate relay 2KA1 is connected to the second end of the third indicator light 2HG and the second circuit breaker F-QF, and the normally open contact of the intermediate relay 2KA1 The contact is connected to the second end of the fourth indicator light 2HR and the second circuit breaker F-QF, and the first end of the third indicator light 2HG and the first end of the fourth indicator light 2HR are connected to the generating voltage together. When the power generation voltage is connected, the coil of the intermediate relay 2KA1 is energized, the normally closed contact of the intermediate relay 2KA1 is disconnected, the normally open contact of the intermediate relay 2KA1 is closed, the third indicator light 2HG is off, and the fourth indicator light 2HR is on. , to indicate the normal closing working state of the second circuit breaker F-QF; when the generator voltage is not connected or the power supply of the generator fails or the second circuit breaker F-QF fails to connect the generator voltage, the coil of the intermediate relay 2KA1 No power supply, the normally closed contact of the intermediate relay 2KA1 remains closed, the normally open contact of the intermediate relay 2KA1 remains open, the third indicator light 2HG is on, and the fourth indicator light 2HR is off. The opening working status is indicated.

In one of the embodiments, the mains power generation power switching circuit further includes: a first protection circuit 16 and a second protection circuit 17 .

The first protection circuit 16 is respectively connected with the mains power supply, the detection relay KA and the first circuit breaker S-QF, and is configured to perform overcurrent protection on the mains voltage; the second protection circuit 17 is respectively connected with the power generation power supply and the second circuit breaker F-QF connection, configured for over-current protection of the generator voltage.

In a specific implementation, both the first protection circuit 16 and the second protection circuit 17 include fuses. For example, as shown in FIG. 4 , the first protection circuit 16 adopts the fuse 1FU1, and the second protection circuit 17 adopts the second fuse 1FU1, which can To prevent the current corresponding to the mains voltage and the power generation voltage from being too large or the temperature of the mains power supply and the power generation power supply is too high to damage the mains power supply and the power generation power supply and the electronic components in the back-end circuit, and improve the switching circuit of the mains power generation power supply. Safety and reliability.

In one of the embodiments, the detection relay KA includes at least two intermediate relays. To achieve multiple guarantees, only one of the mains power supply and the power generation power supply is connected to the load to supply power to the load.

In one of the embodiments, please refer to FIG. 4 , the detection relay KA includes: a first intermediate relay 1KA1 and a second intermediate relay 1KA2; wherein the coil of the first intermediate relay 1KA1 and the coil of the second intermediate relay 1KA2 are connected to the commercial power supply Connection, the normally closed contact of the first intermediate relay 1KA1 is connected with the normally closed contact of the second intermediate relay 1KA2, the normally closed contact of the first intermediate relay 1KA1 is also connected to the power generation source, and the normally closed contact of the second intermediate relay 1KA2 The point is also connected to the second circuit breaker S-QF.

In the specific implementation, please refer to FIG. 4, the detection relay KA includes a first intermediate relay 1KA1 and a second intermediate relay 1KA2, the normally closed contact of the second intermediate relay 1KA2 is connected in series with the coil of the second time relay 2KT, and then opens with the second intermediate relay The first intermediate relay 1KA1 and the second intermediate relay 1KA2 can detect whether it is connected to the mains. When the mains is connected, the coil of the first intermediate relay 1KA1 and the coil of the second intermediate relay 1KA2 are all connected to the mains. electricity, so that the normally closed contacts of the first intermediate relay 1KA1 and the normally closed contacts of the second intermediate relay 1KA2 are both disconnected, thereby disconnecting the connection between the power generation source and the second circuit breaker F-QF, that is, disconnecting the power generation The power supply is supplied by the mains power supply to the load to prevent the mains power supply and the generator power supply from running in parallel; when the mains power supply is not connected or the mains power supply fails, the coil of the first intermediate relay 1KA1 and the coil of the second intermediate relay 1KA2 shall not be powered , so that the normally closed contact of the first intermediate relay 1KA1 and the normally closed contact of the second intermediate relay 1KA2 are kept closed, thereby connecting the power generation source and the second circuit breaker F-QF, and the power generation power source provides the power generation voltage to supply power to the load; According to the above logic, when the mains power supply is restored, the power generation power is disconnected, and the mains power supply is given priority to supply power to the load. Through the two intermediate relays, double insurance can be realized. Only one of the mains power supply and the power generation power supply supplies power to the load, which effectively improves the safety and reliability of the mains power generation power switching circuit and improves the safety and reliability of power supply. .

In the specific implementation, the first circuit breaker S-QF connected between the live line S-L of the mains and the neutral line S-N of the mains and its peripheral circuits constitute the automatic control loop of the first circuit breaker S-QF, which is connected to the power generation source The second circuit breaker F-QF between the live line F-L and the neutral line F-N of the generating power supply and its peripheral circuits constitute the automatic control loop of the second circuit breaker F-QF.

The following will briefly describe the working principle of the mains power generation power switching circuit with reference to Figure 4:

Initial state: There is electricity in the mains, and the diesel generator is in a shutdown and standby state.

In manual mode, turn the mode switch SA to the "manual" position, and the user can use the corresponding opening and closing buttons on the low-voltage cabinet door (the closing button 1SBC of the first circuit breaker S-QF and the first circuit breaker The opening button 1SBS of S-QF, and the closing button 2SBC of the second circuit breaker F-QF and the opening button 2SBS of the second circuit breaker F-QF) to the first circuit breaker S-QF and the second circuit breaker F -QF performs opening and closing control, and realizes manual control to switch between the mains power supply and the generator power supply to supply power to the load.

When it is automatic, turn the mode switch SA to the "automatic" position, the automatic control circuits of the first circuit breaker S-QF and the second circuit breaker F-QF are connected, and the first time relay in the mains control circuit is 1KT The coil is energized, the normally open contact of the first time relay 1KT is closed with a delay (the delay time is adjustable from 0 to 60 seconds), and the closing coil X of the first circuit breaker S-QF is connected with a delay, so that the first The circuit breaker S-QF is closed. At this time, the mains supply power to the load. At the same time, the coil of the relay KA (including the first intermediate relay 1KA1 and the second intermediate relay 1KA2) is energized, and the normally closed contact of the detection relay KA is broken. Open, cut off the second circuit breaker F-QF to prevent the parallel operation of the mains and generator power supply; when the mains fails, the undervoltage release of the first circuit breaker S-QF acts to make the first circuit breaker S- QF is opened, the normally closed auxiliary contacts of the first circuit breaker S-QF are reset and closed, so that the generator starts to generate electricity, and at the same time, the coil of the relay KA (including the first intermediate relay 1KA1 and the second intermediate relay 1KA2) is detected to be de-energized. The normally closed contact of the relay KA is reset and closed, so that the coil of the second time relay 2KT in the power generation control circuit is energized, and the normally open contact of the second time relay 2KT is delayed and closed (the delay time is adjustable from 0 to 60 seconds) , the closing coil X of the second circuit breaker F-QF is turned on after a delay, so that the second circuit breaker F-QF is closed, and the generator generates power to supply power to the load at this time; The coil of the relay KA (including the first intermediate relay 1KA1 and the second intermediate relay 1KA2) is energized, the normally closed contact of the detection relay KA is disconnected, and the undervoltage release of the second circuit breaker F-QF acts to open the second circuit. At the same time, the coil of the first time relay 1KT of the mains control circuit is energized, so that the normally open contact of the first time relay 1KT is delayed to close, and the closing of the first circuit breaker S-QF is turned on. The brake coil, the first circuit breaker S-QF is closed, and the load is powered by the mains, and the normally closed auxiliary contact of the first circuit breaker S-QF is disconnected to stop the generator, thereby realizing automatic switching between mains and power generation. Generator and ensure the priority power supply of the mains.

A second aspect of the embodiments of the present application provides a power distribution system, where the power distribution system includes a commercial power source, a power generation source, a load, and the commercial power generation source switching circuit described in any one of the above.

The embodiment of the present application can automatically, quickly and effectively switch the mains power supply and the power generation power supply to supply power to the load. The power supply switching time is short and the efficiency is high, which reduces the economic loss caused by the excessively long power switching time, reduces the cost, and improves the power distribution system. safety, reliability and practicality.

Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned functions can be allocated to different functional units, Module completion, that is, dividing the internal structure of the device into different functional units or modules to complete all or part of the functions described above. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing from each other, and are not used to limit the protection scope of the present application.

In the foregoing embodiments, the description of each embodiment has its own emphasis. For parts that are not described or described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above-mentioned embodiments, those of ordinary skill in the art should understand that: it is still possible to implement the above-mentioned implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the application, and should be included in the within the scope of protection of this application.

Claims (9)

1. The utility model provides a commercial power generation power supply switching circuit, is connected with commercial power supply, power generation power supply and load respectively, its characterized in that, commercial power generation power supply switching circuit includes:

a first circuit breaker connected to the commercial power source and the load, respectively, and configured to control a connection state between the commercial power source and the load;

the coil of the detection relay is connected with the mains supply and is configured to detect the mains supply voltage output by the mains supply and generate a mains supply detection signal;

the second circuit breaker is respectively connected with the first circuit breaker, the power generation source, the load and the detection relay and is configured to control the connection state between the power generation source and the load according to the commercial power detection signal; wherein the load is connected to at most one of the mains power supply and the power generation power supply.

2. The mains-generated power supply switching circuit of claim 1, further comprising:

the first time relay is respectively connected with the mains supply, the normally closed auxiliary contacts of the first circuit breaker and the second circuit breaker and is configured to be communicated with the closing coil of the first circuit breaker in a time-delay mode according to the mains supply voltage;

and the second time relay is respectively connected with the power generation power supply, the second circuit breaker, the normally closed auxiliary contact of the first circuit breaker and the normally closed contact of the detection relay and is configured to be communicated with the closing coil of the second circuit breaker in a time-delay manner according to the power generation voltage.

3. The mains-generated power supply switching circuit of claim 2, further comprising:

the mode conversion switch is respectively connected with the mains supply, the power generation supply, the first time relay and the second time relay and is configured to switch a power distribution mode according to a first input signal;

and the gate control assembly is respectively connected with the mode change-over switch, the normally closed auxiliary contact of the second circuit breaker, the first circuit breaker, the normally closed auxiliary contact of the first circuit breaker and the second circuit breaker and is configured to be communicated with the mains supply or the power generation power supply according to a second input signal.

4. The mains-generated power supply switching circuit of claim 1, further comprising:

and the first indicating circuit is respectively connected with the mains supply and the first circuit breaker and is configured to indicate the state of the first circuit breaker according to the mains voltage.

5. The mains-generated power supply switching circuit of claim 1, further comprising:

and the second indicating circuit is respectively connected with the power generation power supply and the second circuit breaker and is configured to indicate the state of the second circuit breaker according to the power generation voltage.

6. The mains-generated power supply switching circuit of claim 1, further comprising:

the first protection circuit is respectively connected with the mains supply, the detection relay and the first circuit breaker and is configured to perform overcurrent protection on the mains supply voltage;

and the second protection circuit is respectively connected with the power generation power supply and the second circuit breaker and is configured to perform overcurrent protection on the generated voltage.

7. The mains-generated power switching circuit of claim 1, wherein the detection relay comprises: a first intermediate relay and a second intermediate relay; wherein,

the coil of first auxiliary relay with the coil of second auxiliary relay with mains power supply connects, the normally closed contact of first auxiliary relay with the normally closed contact of second auxiliary relay is connected, the normally closed contact of first auxiliary relay still with power generation source connects, the normally closed contact of second auxiliary relay still with the second circuit breaker is connected.

8. The mains power switching circuit of claim 1, wherein a mechanical interlock and an electrical interlock are further provided between the first circuit breaker and the second circuit breaker.

9. An electrical distribution system, comprising: a mains supply, a power generation supply, a load and a mains power generation supply switching circuit as claimed in any one of claims 1 to 8.

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