Analysis Methodology for Evaluation of Time-Delay Impact on Network-Based System for Droop-Controlled AC Microgrid

Abstract

Potential performance improvements can be obtained by introducing communication techniques in the power electronic systems. However, network-induced time-delay could bring negative consequences of degrading performance or destabilizing the system in many cases. To investigate and handle the impacts of time-delay, a suit of analytical methodology is proposed, where both delay-insensitive and delay-sensitive control strategies of network-based system have their theoretical methods and different problem-solving paths. The former is to predict the maximum allowable boundaries of time-delay for releasing more network resources, and the latter is to use the controller-altering method for changing its original instability, respectively. The proposed methodology is concretely applied in network-based system of droop-controlled AC (Alternating Current) microgrid in islanded mode. Two different current-sharing strategies are mathematically analyzed and given to verify their validity. Experimental results also show the effectiveness of the proposed methodology in droop-controlled AC microgrid system, which provides theoretical guidance on how to use network-based control for the other power electronic systems.

A fully probabilistic control framework for stochastic systems with input and state delay

“…This leads to the randomised control solution specified by the following theorem, Theorem 3 By substituting the ideal distribution of the system dynamics (13), the ideal distribution of the controller (14), and the actual distributions of the system dynamics (12) into Eqs. (8)(9)(10), the optimal randomised controller c(u…”

Recent Developments in Time-Delay Systems and Their Applications

“…As for networked control systems, some significant issues are addressed: the impact of delays on network-based systems for droop-controlled AC microgrid is investigated in Reference [8]; Tracking control for cloud robotic systems with delayed measurements is considered in Reference [9]; An event-triggered fault detection approach to cyber-physical systems with sensor nonlinearities and deception attacks is presented in Reference [10]; and a non-standard discretization method is introduced to stability analysis of sampled-data systems in Reference [11].…”