Photovoltaic power generation physical reference control method

Abstract

The invention relates to a photovoltaic power generation physical reference control method, in particular to a control method adopting physical reference, and belongs to the field of photovoltaic power generation or optimal control methods. The photovoltaic power generation real object reference control method realizes the maximum output power of the photovoltaic cell. According to the first method, the open-circuit voltage and the short-circuit current of the reference photovoltaic cell are measured, the optimal reference resistance is calculated, and the working photovoltaic cell is controlled to reach the maximum output power. The second method comprises the following steps: measuring the open-circuit voltage and the short-circuit current of the reference photovoltaic cell, measuring the current at 80% of the open-circuit voltage and the voltage at 80% of the short-circuit current, calculating the optimal reference resistance, and controlling the working photovoltaic cell to reach the maximum output power. The third method comprises the following steps: measuring the open-circuit voltage or short-circuit current of the reference photovoltaic cell, scanning in a range of 50%-100% of the open-circuit voltage or short-circuit current, measuring the current or voltage at the same time, calculating the voltage and current or optimal reference resistance when the maximum output power is recorded, and controlling the working photovoltaic cell to reach the maximum output power.

Description

technical field [0001] The invention relates to a photovoltaic power generation physical reference control method, in particular to a control method using physical reference instead of model reference, and belongs to the field of photovoltaic power generation or optimal control methods. Background technique [0002] Green and environmentally friendly photovoltaic power generation is one of the important development directions of clean energy. [0003] Photovoltaic power generation converts solar energy into electrical energy. An important technology is to emit as much electrical energy as possible under the same light conditions. The simple circuit model and common circuit model of photovoltaic cells are as follows: Figure 1a , 1b shown. [0004] A simplified circuit model of a photovoltaic cell is figure 2 As shown, the corresponding mathematical model is Among them: I L is the photogenerated current, I S is the reverse saturation current, the ideal constant A usual...

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Problems solved by technology

[0004] A simplified circuit model of a photovoltaic cell is figure 2 As shown, the corresponding mathematical model is Among them: I L is the photogenerated current, I S is the reverse saturation current, the ideal constant A usually takes 1~2, U T =KT / q, T is the thermodynamic temperature, Boltzmann constant K=1.38*10 -23 J / K, charge q=1.6*10 -19 C, U at room temperature T ≈26mV; It can be seen that the volt-ampere characteristics of photovoltaic cells are nonlinear. Since the photo-generated current and parameters inside photovoltaic cells will change with changes in light intensity and ambient temperature, it is difficult to control photovoltaic power generation to achieve maximum power output.

[0005] At present, the monitoring of the working state of photovoltaic cells and the preset algorithm of the controller are used to adjust the load rate to achieve the maximum power output of photovoltaic power generation. The circuit diagram is as follows image 3 As shown, although the circuit structure of this method is relatively simple, the control algorithm is more complex, the optimization speed is slow, the effect is poor when the weather changes rapidly, and sometimes even stability problems occur

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