Parallel-operation photovoltaic mains supply hybrid power supply device

Abstract

The invention belongs to the technical field of photovoltaic power generation, and particularly relates to a parallel-operation photovoltaic mains supply hybrid power supply device. According to the device, a solar photovoltaic array is adopted for power generation, 48V isolated direct current is converted into 100Hz pulsating waves with the amplitude of 311V after being buffered by a lithium battery pack, 50Hz alternating current 220V is converted into 100Hz pulsating waves with the amplitude of 311V for hybrid confluence power supply, and finally, the 311V pulsating waves obtained after photovoltaic electric energy and a power grid are mixed are converted into 50Hz sine waves through an inverter circuit. A single-chip microcomputer is used for accurately tracking the phases and amplitudes of pulsating waves output by a power grid and a photovoltaic device and is used for photovoltaic power generation and power grid hybrid scheduling; the device is high in mixing efficiency and convenient to dispatch, solves the problem that existing grid-connected photovoltaic power generation and off-grid photovoltaic power generation cannot be dispatched in a mixed mode, and meanwhile can be seamlessly switched to a pure off-grid mode, a pure power grid mode, a solar energy mode and a power grid electric energy mixed power supply mode. And a single-phase alternating-current parallel operation mode and a three-phase alternating-current parallel operation mode or a single-machine working mode can be configured according to actual requirements.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic power generation, and in particular relates to a photovoltaic mains hybrid power supply device that can be paralleled. Background technique [0002] At present, photovoltaic power generation has been commercialized on a large scale, and has produced good economic benefits. However, at present, the mainstream of photovoltaic power generation technology adopts grid-connected power generation, that is, the electricity generated by photovoltaics is integrated into the grid. There are following deficiencies: [0003] 1. Incorporation into the power grid requires application for approval procedures, which is cumbersome, and some areas do not even allow grid connection due to transformer load problems; [0004] 2. The dispatching capacity of the power grid is limited, and it is inconvenient for large-scale photovoltaic power generation to be integrated into the power grid; [0005] 3. For househo...

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Problems solved by technology

[0003] 1. Incorporation into the power grid requires application for approval procedures, which is cumbersome, and some areas do not even allow grid connection due to transformer load problems;

[0004] 2. The dispatching capacity of the power grid is limited, and it is inconvenient for large-scale photovoltaic power generation to be integrated into the power grid;

[0005] 3. For household single-phase grid-connected inverters, excessive grid-connected power may easily cause three-phase imbalance, which restricts single-phase grid-connected power generation;

[0006] 4. It is inconvenient to use for isolated island off-grid power supply or when power grid failure occurs

[0008] 1. The power of a stand-alone machine is generally small, which cannot meet the high-power use above 6kVA;

[0009] 2. Solar energy and grid energy cannot be used at the same time. If the power load is too heavy, all loads will be switched to grid power supply, which will lead to idle waste of solar energy, so that the energy-saving benefits of solar energy cannot be maximized;

[0010] 3. If the switching time is too long during the load switching process, it may cause power failure and shutdown of household equipment;

[0011] 4. When using off-grid inverters, because they completely rely on battery packs for power supply during inversion, the rated current and capacity of the battery packs and inverters that need to be equipped are often relatively large, bulky and expensive

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