Isochronous oscillation method based on improved active disturbance rejection for photovoltaic thermal-power bundling

Abstract

The invention discloses an isochronous oscillation method based on improved active disturbance rejection for photovoltaic thermal-power bundling. On the base of a traditional damping controller, the method introduces a non-linear active-disturbance-rejection control specific to a photovoltaic thermal-power bundling series-compensation output system. The method comprises the steps of using the designed improved active disturbance rejection controller with additional damping to collect speed error signals of coal-fired power units, and obtaining a speed component as a controlled object under each type of oscillation states after filtering; after four processes of tracking differentiators, extending state observers, feeding back non-linear errors and disturbing estimation compensation, making each speed component track the reference values of the speed component without overshooting in a short time; adopting fuzzy control to set parameters of error feedback and make the parameters adapt to the characters of high photovoltaic volatility and variable operational states; superimposing generated control signals on a current-mode control section of a photovoltaic inverter to enhance system damping. The isochronous oscillation method based on improved active disturbance rejection for photovoltaic thermal-power bundling provides a novel idea for subsynchronous oscillation suppression which contains a new energy grid connection.

Description

technical field [0001] The invention belongs to the field of electric power systems, and in particular relates to a method for suppressing subsynchronous oscillation of light-fire bundling based on improved self-disturbance rejection. Background technique [0002] Solar energy is a clean and renewable energy that has been vigorously developed in recent years. As the capacity of photovoltaic power plants increases, bundling them with traditional thermal power is an economically feasible power transmission method. In the AC transmission system, the series compensation technology is generally used to improve the transmission capacity of the transmission line. However, the AC series compensation may cause the interaction between the generator and the grid, resulting in the subsynchronous oscillation of the thermal power unit, which seriously affects the stable operation of the power system. [0003] Existing research has paid little attention to the subsynchronous oscillation ...

AI Technical Summary

Problems solved by technology

However, when using PID control, it is difficult to effectively coordinate between "overshoot" and "rapidity", and the accuracy of the system model is required to be high

At the same time, photovoltaic power plants are greatly affected by climate and light, and have high requirements for the adaptability of controller parameters. Traditional PID control is difficult to adapt to the complex and changeable characteristics of photovoltaic operating conditions.

Using modern control methods such as intelligent algorithms to optimize the control parameters of PID, although the suppression effect of subsynchronous oscillation can be improved, but it is highly dependent on the accuracy of the system model, resulting in limitations in its control function

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