Photovoltaic mains compensation device and control method for water pump system

Abstract

The invention provides a photovoltaic mains supply compensation device for a water pump system and a control method. The photovoltaic mains supply compensation device comprises a photovoltaic array, abidirectional AC-DC converter, a first DC-DC converter, a second DC-DC converter, a three-phase inverter, a three-phase AC water pump, a startup controller, an MPPT controller and a mains supply compensation controller, wherein the first DC-DC converter converts output voltage of the photovoltaic array; the bidirectional AC-DC converter supplements the power needed by a load when the photovoltaicpower is insufficient, and feeds the surplus power back to a power grid when the photovoltaic power is sufficient; the second DC-DC converter boosts the voltage of a DC bus; the three-phase inverterdrives the three-phase AC water pump; the MPPT controller tracks the maximum power of the photovoltaic array; the startup controller starts the water pump; and the mains supply compensation controllerdecides the power flowing direction of the bidirectional AC-DC converter. The photovoltaic mains supply compensation device judges the relationship between the output power of the photovoltaic arrayand the load through monitoring voltage changes of the DC bus, and compensates the insufficient power of the photovoltaic output or recycle of the residual power, thereby utilizing the solar energy tothe greatest extent, and ensuring the water pump system to continuously operate around the clock at the same time.

Description

technical field [0001] The invention relates to the field of water pumps, in particular to a photovoltaic mains compensation device and a control method for a water pump system. Background technique [0002] Traditional photovoltaic water pump systems usually use solar energy as the only energy source, and water can only be discharged when the light intensity meets certain requirements, which places a large limit on the working time of photovoltaic water pump systems. In addition, when the light intensity changes drastically, it may cause the system to start and stop frequently, which will cause a large impact on the system and affect the system stability and production efficiency. Therefore, it is still difficult for the traditional photovoltaic water pump system to be applied to occasions requiring a large amount of stable water, such as large factories and residential areas. [0003] Patent document CN206775228U discloses a power compensation controller for an AC photovo...

AI Technical Summary

Problems solved by technology

However, this method only considers the insufficient output power of the photovoltaic array, and there are no specific recovery measures when the output power of the photovoltaic array is excessive, resulting in energy waste

[0006] In addition, in order to compare the power of the photovoltaic side and the load side, it is necessary to install power measurement devices separately, which increases the complexity of the system and the construction cost

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