Automatic alternating current and direct current switching power supply system

Abstract

The invention discloses an automatic alternating current and direct current switching power supply system. The system is characterized by comprising a three phase and two phase shifting circuit connected with an outside three-phase alternating current power supply, a first resistor, an IGBT switching circuit and a three-phase rectifying circuit which are sequentially connected with a two-phase circuit end of the three phase and two phase shifting circuit and a photovoltaic cell panel input connection line connected with the three-phase rectifying circuit, wherein the other end of the photovoltaic cell panel input connection line is connected with an external photovoltaic cell panel power supply output end, the automatic alternating current and direct current switching power supply system further comprises a voltage detecting circuit and an MCU module, the voltage detecting circuit is connected with the photovoltaic cell panel input connection line, and the automatic alternating currentand direct current switching power supply system further comprises a relay which is connected with the first resistor in parallel and is used for supplying power to an outside water pump motor. By means of the automatic alternating current and direct current switching power supply system, an automatic alternating current and direct current switching function of a photovoltaic pumping system is achieved, moreover, compared with a mode of alternating current power supply input controlled by an alternating current contactor, the automatic alternating current and direct current switching power supply system has the advantages that a system scheme is simplified, the reliability is improved, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of power supply circuits, in particular to an AC-DC automatic switching power supply system. Background technique [0002] For the photovoltaic water pumping system, when the light conditions are sufficient, the solar energy is used to pump and store water. When the light conditions are weak, the grid power is used to drive the photovoltaic water pump inverter. In the past photovoltaic water pumping systems, a photovoltaic water pump is usually used Inverter, DC circuit breaker, AC circuit breaker, manual transfer switch, terminal block, electrical cabinet, etc., such as figure 2 As shown, this structure requires a manual switching switch, and the installation location of the photovoltaic water pumping system electrical cabinet and photovoltaic panels is usually far away from the user's residence, which brings inconvenience to the user's operation. [0003] In view of the above problems, there is also a pow...

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Problems solved by technology

[0002] For the photovoltaic water pumping system, when the light conditions are sufficient, the solar energy is used to pump and store water. When the light conditions are weak, the grid power is used to drive the photovoltaic water pump inverter. In the past photovoltaic water pumping systems, a photovoltaic water pump is usually used Inverter, DC circuit breaker, AC circuit breaker, manual transfer switch, terminal block, electrical cabinet, etc., such as figure 2 As shown, this structure requires a manual switching switch, and the installation location of the photovoltaic water pumping system electrical cabinet and photovoltaic panels is usually far away from the user's residence, which brings inconvenience to the user's operation

[0003] In view of the above problems, there is also a power grid switching circuit, such as image 3 As shown, but this kind of scheme first needs to increase the AC contactor, and the system cost will increase obviously; secondly, it needs to add a separate 220V ~ AC power supply to drive the AC contactor coil, the wiring of the system is complicated, and the AC contactor coil is very important for the drive. The voltage has certain requirements. When the 220V ~ power supply is unstable, it is easy to burn the contactor coil, so this solution is not suitable for areas with unstable power grids

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