Control method and device for preventing MPPT misjudgment

Abstract

The invention provides a control method and device for preventing MPPT misjudgment. In the method, a first working point, a second working point and a third working point are acquired first. Due to the fact that a characteristic curve of a photovoltaic cell determines that the power of the maximum power point is the highest and the power of points at other positions is lower than that of the maximum power point, if the current moving direction is correct, the third working point should be closer to the maximum power point than the second working point, and namely, the power of the third working point is higher than that of the second working point. Thus, when the power of the second working point is higher than that of the third working point, it can be determined that misjudgment occurs. Then, the next working point behind the third working point moves in the reverse direction so that the moving direction of the working points of the photovoltaic cell can be adjusted in time. According to the control method and device, the judgment principle is simple and fast and easy to realize, and therefore adjustment can be carried out in time after misjudgment of the photovoltaic cell occurs, and the utilization ratio of solar energy can be increased.

Description

technical field [0001] The invention relates to the technical field of automatic control, in particular to a control method and device for preventing MPPT misjudgment. Background technique [0002] Now solar energy is one of the new energy sources. In order to convert solar energy into usable electrical energy, a circuit with MPPT (max power point tracking, maximum power tracking) function is needed. This circuit uses photovoltaic cells to convert solar energy into electrical energy. The PU characteristic curve when the light intensity is constant is as follows: figure 1 As shown, where the horizontal axis is the voltage U, and the vertical axis is the power P, by figure 1 It can be seen that there is a maximum power point in the entire PU characteristic curve of the photovoltaic cell, which is called the MPP point. The greater the power of the photovoltaic cell, the more output power and the higher the utilization rate of solar energy. Therefore, during the working process...

AI Technical Summary

Problems solved by technology

[0013] The invention provides a control method and device for preventing the misjudgment of the MPPT circuit. The invention can effectively solve the problem of misjudgment of the MPPT circuit and cause the problem of low use of photovoltaic cells, thereby improving the solar energy utilization rate of the MPPT circuit

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