An Exponential Convergence Control Method for Global Stability of Flexible HVDC Transmission System

Abstract

The invention discloses an exponential convergence control method for the global stability of a voltage source converter based high-voltage direct-current (VSC-HVDC) system, comprising the following steps: (1) obtaining a PCHD model of a VSC-HVDC system; (2) presetting an energy function of the VSC-HVDC system, and changing the original energy function of the system according to a preset interconnection matrix Jd and a damping matrix Ra(x) to obtain a new PCHD model when the VSC-HVDC system is passive; (3) selecting a steady-state equilibrium point needed by the VSC-HVDC system, constructing a needed closed-loop storage function Hd(x), and enabling the closed-loop storage function Hd(x) to meet the conditions of an IDA-PB theorem; and (4) obtaining an exponential stability IDA-PB controller of the VSC-HVDC system, and controlling the VSC-HVDC system according to the exponential stability IDAPB controller. By adopting the method, the VSC-HVDC system is enabled to have good steady-state and transient property when the system is under large disturbance or system parameters cannot be accurately predicted, and the global asymptotic stability is maintained.

Description

technical field [0001] The invention belongs to the design field of a converter station, especially a converter station control system of a flexible direct current transmission system, and relates to an exponential convergence control method and an exponential convergence control method for global stability of a flexible direct current transmission system. Background technique [0002] The core of the flexible direct current transmission system based on the voltage source converter is the use of fully controlled turn-off power electronic devices and pulse width modulation (PWM) technology. It can be used not only to connect to the conventional AC power grid, but also to supply power to the passive network and improve its power quality. It can also realize independent control of active power and reactive power and four-quadrant operation. It is convenient to connect to the multi-terminal DC transmission system and realize Static synchronous compensator (STATCOM) and other fun...

AI Technical Summary

Problems solved by technology

However, traditional PI controllers are more difficult to set and optimize parameters, and the transient adjustment process is longer and the robustness is poor.

However, due to the nonlinearity, strong coupling, and multi-input characteristics of the VSC-HVDC control system, it is often difficult for control systems using other methods to achieve good dynamic performance and eliminate steady-state errors while maintaining large-scale asymptotic stability.

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