Stability and Stabilization Scheme for Systems with Time Delay

Abstract

This paper describes stability analysis and a stabilizing control design for a system with time delay. A delay often occurs when the transmission path includes a computer network. For a time delay, the stability analysis in the frequency domain approach is not sufficient; thus, stability analysis in the time domain is required and typical method is based on the Lyapunov-Krasovskii functional (LKF). This paper describes stability analysis and the design of stabilizing controllers based on various types of LKFs. The paper also describes a model-based control for a system with time delay and it resolves the issue on the communication disturbance observer (CDOB), which generates steady state error if there exists model error. Results of experiments conducted on a DC motor are shown and they confirmed the validity of the proposed model based control method.

Robust-control using model-error-feedback CDOB and DOB under variable-time-delay

“…Due to this, it is not easy to decrease the conservative of the controllers. On the other hand, the papers [13], [14] have proposed the CDOB consists of H∞ state observer based on LKF. Additionally, the controller considers the CDOB is also proposed.…”

“…The structure of frequency-weight G f w shown in Fig. 2 is LPF in [13], [14], and discussed in III-A.…”

“…To solve the destabilization caused by time-delay, some compensation methods have been proposed [8]- [14]. The first method is "smith-method", this uses a time-delay model for feedforward controller.…”

“…Whereas, it is difficult to decrease the conservative of the H∞ controller. As one of solutions, it has been proposed that CDOB modified by using the LKF based design [13] [14]. The papers presents a design method of CDOB considering LKF, it consists of H∞ state-observer based on the LMI.…”

Complete Models of Transmission-connected Photovoltaic Plant Using Modularity Principle for Power System Small Signal Stability Study

“…Under this circumstance, some control signals may come from the cyber system. As a result, network induced problems may occur such as the time delay, the packet losing and so on (9) (10) . So, in order to meet the needs of the future smart a) Correspondence to: Yichen Zhou.…”