Active disturbance control method of flexible direct current power transmission system

Abstract

The invention relates to an active disturbance control method of a flexible direct current power transmission system. The method adopts the technical scheme that the method comprises the following steps that a rectifier controller is arranged at the head end of a direct current power transmission line of the flexible direct current power transmission system to carry out the constant direct current voltage control on a rectifier at the alternating current system side, an inverter controller is arranged at the tail end of the direct current power transmission line to carry out the constant alternating current voltage control on an inverter, and a double-closed loop type vector control strategy is adopted for the constant alternating current voltage control of the inverter, wherein an outer loop of the voltage is controlled by an active disturbance controller, an inner loop is controlled by current decoupling, and the direction of bus voltage at the inverter alternating current side is fixed to the direction of an axis d. The method has the advantages that the overshoot of the bus voltage at the passive network alternating current side is reduced when the flexible direct current power transmission system starts to respond, the precision and the stability of the alternating current voltage control are improved, the inside and outside total disturbance of the flexible direct current power transmission system can be evaluated in a real-time way, the feedforward compensation can be timely carried out, the disturbance control capability of the flexible direct current power transmission system is improved, and the control requirements of a non-linear system can be met.

Description

technical field [0001] The invention relates to the technical field of direct current transmission, in particular to an active disturbance rejection control method in a flexible direct current transmission system. Background technique [0002] Traditional high-voltage direct current transmission (HVDC) has many incomparable advantages over AC transmission, such as the transmission capacity is not limited by stability, asynchronous networking can be realized, there is basically no capacitive current in the line, and no reactive power compensation is required. However, since the traditional HVDC uses the thyristor as the converter device, and the thyristor is a semi-controlled device, the AC side needs to provide a reverse voltage when it is turned off, which requires that the AC side connected to it must be an active network; at the same time, the HVDC is running in the inverter , prone to commutation failure and other failures. [0003] Flexible DC transmission is the high-...

AI Technical Summary

Problems solved by technology

For a multivariable, strongly coupled, nonlinear system such as VSC-HVDC, it is difficult for the PID regulator to meet the requirements of the actual system under different working conditions. The main disadvantages are as follows:

[0006] (2) Since the PID control directly uses the error between the given signal and the actual output of the controlled object as the signal to be compensated, this often results in the control quantity output by the PID controller at the start of operation Too large, causing the actual output signal of the controlled object to overshoot

[0007] (3) PID control is a linear combination, which is difficult to meet the requirements of high-performance control for nonlinear systems in actual engineering

[0008] (4) When the system is subject to random disturbance, PID control cannot achieve obvious control effect

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