Maximum power point tracking method for dP/dV I near-linear photovoltaic generating system

Abstract

The invention belongs to the light volt generating system controlling technology domain, the independent light volt generating system based on the maximal power point tracing technology includes: (1)the solar cell; (2)the storage cell; (3)BUCK circuit; (4)the light voltage combining net system. Because of the light volt cell array having the dP / Dv and I almost linear characteristic connection when working in the maximal power working point and the stable working zone. The invention is aiming at the adopt the light volt array output circuit, the MPPT controlling of the light volt array can be realized by controlling BUCK circuit accounting empty percent as the power switching tache or the PWM driving signal of the combining net system reverse changing machine. When the light intension has the quick change, the light volt array output circuit can trace the change with the lineal, the quick and the smooth mode, the light volt cell array maximal power point trace controlling can be realized better.

Description

technical field [0001] The invention relates to a maximum power point tracking method applied in an independent and grid-connected photovoltaic power generation system, and belongs to the technical field of photovoltaic power generation system control. Background technique [0002] The independent photovoltaic power generation system has its own energy storage link, which can provide continuous power output without being connected to the grid, so it has been gradually applied in remote areas without electricity; the grid-connected photovoltaic power generation system can be equipped with or without energy storage link. The output end is connected to the mains and outputs electric energy to the grid, just like a small distributed power station, the traditional control method is more complicated, usually requires a double-loop control circuit, the inner loop is a current loop to realize the output current of the grid-connected photovoltaic inverter It is output synchronously w...

AI Technical Summary

Problems solved by technology

But the relationship between photovoltaic array dP / dV and V is nonlinear, such as Figure 4 shown

Therefore, various maximum power tracking control conversion methods based on the relationship of dP / dV-V will have some shortcomings, such as complexity and rapidity, and will inevitably cause power fluctuations due to disturbances, resulting in additional losses.

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