Review of Equivalent Methods for Power System

Accurate modeling and simulation for all power and electronic components can greatly improve the simulation accuracy, but the calculation time is too long. Due to the characteristics of centralized operation and distributed control in power network, each region’s data is highly confidential, so it is difficult for the control center of one region to obtain the data of other regions. In actual engineering, the user's research object is often only a certain part of the system, so it is very necessary to perform equivalent calculations on other parts of the system, which can greatly reduce computer memory and improve simulation speed. This review paper introduces the basic principles, advantages and disadvantages of 3 types of equivalent methods, static equivalents, dynamic equivalents and frequency-dependent network equivalents (FDNE), then introduces the development of equivalent software, summarizes the problems existing in equivalent methods at present, and points out possible research directions in the future.