A self-starting safety power supply system

Abstract

This invention discloses a self-starting emergency power supply system, including a power supply circuit, an output circuit, and a diesel generator starting circuit. The power supply circuit includes an AC mains circuit powered by AC mains power and a diesel power supply circuit powered by a diesel generator. The output circuit includes an AC output circuit and a UPS output circuit. The diesel generator starting circuit includes a starting battery, a self-starting circuit, a manual starting circuit, and a diesel engine control circuit. By connecting to the self-starting circuit, the self-starting emergency power supply system of this invention ensures rapid power restoration in the event of AC mains power failure, thus guaranteeing the safety of the power supply line.

Description

Technical Field

[0001] The present invention relates to the technical field of security power supply systems, in particular to a self-starting security power supply system. Background Art

[0002] To ensure the stability of the power grid, a security power supply system is usually configured in the low-voltage distribution system in important power consumption scenarios;

[0003] The security power supply system in the prior art is as follows Figure 1 As shown, Figure 1 The right side of the middle is the diesel generator start-up circuit. Under normal circumstances, the air switch SA1 of the AC mains circuit is closed, and the air switch SA2 of the diesel power supply circuit is also closed. When the voltage relays KV1 and KV2 detect that the AC mains is normal, they will operate, and their moving contacts KV1 and KV2 will be closed. The coil of the AC contactor KM1 will be energized, and the mains power will be switched to the AC output bus, supplying power to non-critical loads while charging the UPS system;

[0004] If the AC mains power disappears, the voltage relays KV1 and KV2 lose pressure, their make contacts open, the AC contactor KM1 coil loses power, the AC mains power circuit is cut off, and its break contacts close at the same time, opening the diesel power supply circuit. At this time, the diesel generator is started by manually turning the start knob ST (when starting, first turn the start knob ST to the "power on" position, and the diesel generator is filled with oil. After the oil filling is normal, check that the oil level is normal, then turn the start knob ST to the "motor start" position, the diesel generator ignites, and then release the start knob, and the start knob returns to the "power on" position. When the voltage of the diesel generator is lower than 85%, the voltage relays KV3 and KV4 will not operate because they cannot reach their operating voltage. When the voltage of the diesel generator reaches 85% or above the rated voltage, the voltage relays KV3 and KV4 will operate, and their make contacts KV3 and KV4 will close. At this time, the AC mains is still in a state of disappearance, so the coil of the AC contactor KM1 is still in a state of power failure, and its break contacts are still closed. The AC contactor KM2 operates, switching the diesel power supply circuit to the AC output circuit, supplying power to non-important loads while charging the UPS equipment;

[0005] When the AC mains is restored during the power supply of the diesel generator, the voltage relays KV1 and KV2 will be activated, and the AC contactor KM1 will be activated. First, the AC contactor KM1 will be disconnected, causing the diesel generator input circuit KM2 to be demagnetized and disconnected, cutting off the diesel generator, and then switching the AC mains circuit to the AC output circuit. After the AC mains is normally supplied, the diesel generator start knob ST is manually turned to the "0" position to stop the diesel generator.

[0006] In actual operation, the system needs to manually start the diesel generator after AC power failure, and the power supply recovery speed is slow. Because the power failure time is too long, the startup process may be long or the startup procedure may be cumbersome. Some equipment may even have unforeseen problems. Therefore, how to quickly restore power supply is the key to ensuring power supply continuity and protecting equipment. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the present invention provides a self-starting safety power supply system, which ensures that power supply can be quickly restored in the event of AC mains power failure by connecting to a self-starting circuit, thereby ensuring the safety of line power supply.

[0008] To achieve the above object, the present invention adopts the following technical solution:

[0009] The present invention provides a self-starting safety power supply system, comprising a power supply circuit, an output circuit and a diesel generator starting circuit, wherein the power supply circuit comprises an AC mains circuit powered by AC mains and a diesel power supply circuit powered by a diesel generator;

[0010] The output circuit includes an AC output circuit and a UPS output circuit. The AC mains circuit and the diesel power supply circuit are connected in parallel to the AC output circuit. The AC output circuit is also connected to a UPS device. The UPS device is connected to the UPS output circuit. The air switch SA1 linkage switch of the AC mains circuit is connected in series on the connection line between the AC output circuit and the UPS device. The air switch SA2 linkage switch of the diesel power supply circuit is connected in series on the connection line between the UPS device and the UPS output circuit.

[0011] The diesel generator starting circuit comprises a starting battery, a self-starting circuit, a manual starting circuit and a diesel engine control circuit.

[0012] The self-starting safety power supply system of the present invention designs a self-starting circuit and a manual starting circuit in the diesel generator starting circuit, so the automatic starting and manual starting modes can be freely selected. In the automatic starting mode, the diesel generator can automatically start quickly when the city power fails, thereby realizing rapid restoration of power supply and avoiding losses to important units due to power outages.

[0013] The self-starting safety power supply system of the present invention ensures that power supply can be quickly restored in the event of AC mains power failure by connecting to a self-starting circuit, thereby ensuring the safety of line power supply.

[0014] In a further technical solution, in the starting circuit of the diesel generator, the breaking contacts of the input contactor KM1 of the AC mains circuit are connected in series between the positive and negative poles of the starting battery, and the starting mode switching switch QK is connected in series between the positive and negative poles of the starting battery. The starting mode switching switch QK is respectively connected to the self-starting circuit and the manual starting circuit. The breaking contacts of the input contactor KM2 of the diesel power supply circuit are connected in series in the self-starting circuit. The manual starting circuit includes a starting knob ST and a diesel engine control circuit. The other end of the starting knob ST is connected to the self-starting circuit, and an isolation diode is connected in parallel between the self-starting circuit and the manual starting circuit.

[0015] In a further technical solution, the diesel power supply circuit also includes a delay circuit.

[0016] In a further technical solution, the delay loop includes a bridge rectifier circuit.

[0017] The beneficial effects are:

[0018] 1. The self-starting safety power supply system of the present invention is connected to a self-starting circuit, thereby ensuring that power supply can be quickly restored in the event of AC mains power failure, thereby ensuring the safety of line power supply.

[0019] 2. By utilizing the original moving and breaking contacts of the AC contactors KM1 and KM2 in the AC mains circuit and the diesel power supply circuit, only one switching switch QK and an isolation diode are added compared to the prior art, and the cost of upgrading and reconstruction is lower.

[0020] 3. By adding a delay circuit, the diesel generator can be powered on only after it starts normally, solving the self-starting problem when the diesel generator output load is greater than 10% of the rated capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a circuit diagram of a security power supply system in the prior art;

[0022] Figure 2 1 is a circuit diagram of a self-starting safety power supply system according to an embodiment of the present invention.

[0023] 10. AC mains circuit; 20. Diesel power supply circuit; 30. AC output circuit; 40. UPS output circuit; 50. UPS equipment; 60. Starting battery; 70. Diesel engine control circuit. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings:

[0025] Example:

[0026] A self-starting security power supply system, such as Figure 2As shown, it includes a power supply circuit, an output circuit and a diesel generator starting circuit, and the power supply circuit includes an AC mains circuit 10 powered by AC mains and a diesel power supply circuit 20 powered by a diesel generator;

[0027] The output circuit includes an AC output circuit 30 and a UPS output circuit 40. The AC mains circuit 10 and the diesel power supply circuit 20 are connected in parallel to the AC output circuit 30. The AC output circuit 30 is also connected to a UPS device 50. The UPS device 50 is connected to the UPS output circuit 40. The connection line between the AC output circuit 30 and the UPS device 50 is connected in series with the air switch SA1 linkage switch of the AC mains circuit 10. The connection line between the UPS device 50 and the UPS output circuit 40 is connected in series with the air switch SA2 linkage switch of the diesel power supply circuit 20.

[0028] The diesel generator starting circuit includes a starting battery 60 , a self-starting circuit, a manual starting circuit and a diesel engine control circuit 70 .

[0029] When the AC system is powered normally, the AC mains circuit 10 supplies power to all loads, the start knob of the diesel generator start circuit is in the "0" position, the moving contact of the input contactor KM1 of the AC mains circuit 10 is disconnected, and the diesel engine start circuit is reliably inoperative; the diesel power supply circuit 20 is reliably disconnected by KM2.

[0030] During normal operation, the switch QK can be used to select any starting mode under the accident state. Switching to the upper part is "automatic start" and switching to the lower part is "manual start".

[0031] The self-starting safety power supply system of the present invention designs a self-starting circuit and a manual starting circuit in the diesel generator starting circuit, so the automatic starting and manual starting modes can be freely selected. In the automatic starting mode, the diesel generator can automatically start quickly when the city power fails, thereby realizing rapid restoration of power supply and avoiding losses to important units due to power outages.

[0032] The self-starting safety power supply system of the present invention ensures that power supply can be quickly restored in the event of AC mains power failure by connecting to a self-starting circuit, thereby ensuring the safety of line power supply.

[0033] In another embodiment, in the diesel generator starting circuit, the breaking contacts of the input contactor KM1 of the AC mains circuit 10 are connected in series between the positive and negative poles of the starting battery 60, and the starting mode switching switch QK is connected in series between the positive and negative poles of the starting battery 60. The starting mode switching switch QK is respectively connected to the self-starting circuit and the manual starting circuit. The breaking contacts of the input contactor KM2 of the diesel power supply circuit 20 are connected in series in the self-starting circuit. The manual starting circuit includes a starting knob ST and a diesel engine control circuit 70. The other end of the starting knob ST is connected to the self-starting circuit, and an isolation diode is connected in parallel between the self-starting circuit and the manual starting circuit.

[0034] When the AC mains loses power, if the "self-start" mode is selected in advance, the mains input contactor KM1 loses power and the break contact is closed. Since the diesel generator is in a shutdown state in advance, its input contactor KM2 is also in a power-off state, and its break contact is closed, the diesel generator starting motor runs with power, and the diesel generator is started: at this time, because KM1 is in a power-off state after the mains disappears, the break contact of the contactor KM2 coil circuit located in the diesel generator input circuit is still closed, and the diesel generator input starting circuit is opened; after the diesel generator is started by the starter motor, KV3 and KV4 detect that the output voltage of the diesel generator is higher than 85% of the rated voltage, and the make contact is closed, the coil circuit of the diesel generator input contactor KM2 is completely connected, and the contactor KM2 of the open diesel generator input starting circuit is actuated, and its break contact is disconnected, the diesel generator motor circuit is reliably cut off, and the motor stops: at the same time, after KM2 is actuated, the diesel generator power supply is cut off to the AC output circuit 30.

[0035] When the AC power is restored, the AC power input contactor KM1 is actuated, and its break contact KM1a is disconnected, cutting off the operating power supply of the diesel generator input contactor KM2, cutting off the power supply to the diesel generator, and at the same time, KM1 is actuated to supply the AC power to the AC output bus; at the same time, KM1b is actuated to cut off the control power supply of the diesel generator, and the diesel generator automatically stops running.

[0036] If the load carried by the diesel generator is less than 10% of its rated capacity, the input air switch SA2 can be closed under normal circumstances. If the AC mains disappears, the diesel generator can immediately start quickly with load to ensure the continuity of power supply.

[0037] By utilizing the original breaking contacts of the AC contactors KM1 and KM2 of the AC mains circuit 10 and the diesel power supply circuit 20, only one switching switch QK and an isolation diode are added compared to the prior art, and the cost of upgrading and reconstruction is lower.

[0038] This embodiment can ensure that the diesel generator can be quickly started in the event of AC mains failure to supply power to certain special systems. If the total load is less than 10% of the rated capacity of the diesel generator, its air switch SA2 can be closed in advance to make the startup faster, thereby meeting the requirement of improving power supply reliability.

[0039] This system has high reliability. Since the AC contactor has a certain action time, the moving contacts of the two contactors KM1 and KM2 can be guaranteed to be in the state of "open first" and "close later" in turn under any circumstances, so it will not cause abnormal parallel connection of AC mains and diesel generator.

[0040] In another embodiment, if Figure 2 As shown, the diesel power supply circuit 20 also includes a delay circuit.

[0041] By adding a delay circuit, the diesel generator can be powered on only after it starts normally, solving the self-starting problem of the diesel generator when the output load is greater than 10% of the rated capacity.

[0042] In another embodiment, the delay loop includes a bridge rectifier circuit.

[0043] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A self-starting safety power supply system, characterized in that: It includes a power supply circuit, an output circuit and a diesel generator starting circuit, wherein the power supply circuit includes an AC mains circuit powered by the AC mains and a diesel power supply circuit powered by the diesel generator; The output circuit includes an AC output circuit and a UPS output circuit. The AC mains circuit and the diesel power supply circuit are connected in parallel to the AC output circuit. The AC output circuit is also connected to a UPS device. The UPS device is connected to the UPS output circuit. The air switch SA1 linkage switch of the AC mains circuit is connected in series on the connection line between the AC output circuit and the UPS device. The air switch SA2 linkage switch of the diesel power supply circuit is connected in series on the connection line between the UPS device and the UPS output circuit. The diesel generator starting circuit comprises a starting battery, a self-starting circuit, a manual starting circuit and a diesel engine control circuit.

2. The self-starting safety power supply system according to claim 1, characterized in that: In the diesel generator starting circuit, the breaking contacts of the input contactor KM1 of the AC mains circuit are connected in series between the positive and negative poles of the starting battery, and the starting mode switching switch QK is connected in series between the positive and negative poles of the starting battery. The starting mode switching switch QK is connected to the self-starting circuit and the manual starting circuit respectively. The breaking contacts of the input contactor KM2 of the diesel power supply circuit are connected in series in the self-starting circuit. The manual starting circuit includes a starting knob ST and a diesel engine control circuit. The other end of the starting knob ST is connected to the self-starting circuit, and an isolation diode is connected in parallel between the self-starting circuit and the manual starting circuit.

3. The self-starting safety power supply system according to claim 1, characterized in that: The diesel power supply circuit also includes a delay circuit.

4. The self-starting safety power supply system according to claim 3, characterized in that: The delay loop includes a bridge rectifier circuit.

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