Photovoltaic MPPT (Maximum Power Point Tracking) control method and system introducing improved step factor, medium and equipment

Abstract

The invention provides a photovoltaic MPPT (Maximum Power Point Tracking) control method and system introducing an improved step length factor, a medium and equipment. The method comprises the steps of: S1, introducing a step factor in photovoltaic cell MPPT control according to the principle of a perturbation and observation method and the power-voltage characteristics of a photovoltaic cell; and S2, on the basis of the introduced step factor, determining a continuous disturbance direction according to a power difference value before and after disturbance and a voltage difference value before and after disturbance, and obtaining improved photovoltaic cell MPPT control, thereby ensuring convergence speed and precision at the two ends of a characteristic curve. According to the method, the step factor is introduced and used for adjusting the step length of disturbance, so that the step length of MPPT can be dynamically adjusted, and the convergence speed and precision at the two ends of a characteristic curve are guaranteed.

Description

technical field [0001] The invention relates to the field of industrial technology, in particular to a photovoltaic MPPT control method and system introducing an improved step factor, and more specifically to a photovoltaic MPPT control strategy introducing an improved step factor. Background technique [0002] At present, the most widely used MPPT control method for photovoltaic power generation units is the disturbance and observation method, which is also called the hill-climbing search method, which is divided into voltage type and current type, and the voltage type is more common. When using the disturbance observation method, give the voltage a positive disturbance amount ΔU, and calculate the output power P of the photovoltaic cell. If the output power increases, it means that the disturbance direction is correct; otherwise, the disturbance direction is opposite. However, the traditional method uses a fixed step size, and the choice of the step size has a great influe...

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Problems solved by technology

However, the traditional method uses a fixed step size, and the choice of the step size has a greater impact on the perturbation effect.

When the disturbance step size is too large, although the tracking speed is fast, it is not accurate enough, and the system is prone to oscillation; while the disturbance step size is too small, although the tracking speed is relatively slow, once the external environment changes rapidly If a good tracking effect cannot be achieved, how to determine the appropriate step size for fast tracking and better tracking effect is an important issue

[0003] In the existing technology, when the disturbance step size is too large, although the tracking speed is fast, it is not accurate enough, and the system is prone to oscillation; while the disturbance step size is too small, although the tracking speed is relatively slow, it will be more accurate

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