考虑广域信号时滞的直流附加控制器设计

Design of HVDC Supplementary Control Considering Signal Time-delay Based on LMI Method

针对测量信号在广域测量系统中由于信道、传输协议等环节而引入的延迟经过累积将达到严重影响控制器动态性能的问题,分析了信号延迟的产生及其对直流附加控制器动态性能的影响,提出了一种考虑广域测量系统(WAMS)中信号传输延迟的直流附加控制器;并基于线性矩阵不等式方法(LMI)设计了考虑时滞影响的直流附加控制器。根据算例进行了时域仿真分析,并与一种未考虑时滞的控制器进行了比较,所得结果证明LMI方法设计的直流附加控制器的有效性。

Time delay arises in a wide range of practical engineering applications such as signal processing, fiber optics research and VLSI circuit design. The problem of delay and its analysis has already attracted much attention in these areas. The time delay in power system will bring about negative effect too when it accumulates to some extend. HVDC transmission system can be used as a means of dynamic adjustment in power system due to its fast response characteristics. With the new technology of PMUs since the 1990s, it is found that system dynamic performance can be enhanced significantly with respect to inter-area oscillations if remote signals are applied to the damping controller. In this paper a new HVDC supplementary controller based on WAMS signal is designed which can accommodate the transfer time delay. It will deteriorate the control effect when the time delay in transfer channels and those caused by transfer protocols is accumulated to some extent. In this paper, firstly, cause of transfer time delay is analyzed and so its influence on the HVDC supplementary control. Then the new controller is designed based on linear matrix inequality（LMI） theory to accommodate the time delay effect. Last, the new controller is compared with another one which does not consider the time delay effect. By the time domain simulation a conclusion is drawn that this design way is effective.