Search

Location of the static VAR compensator (SVC) and other types of shunt compensation devices is important for the enhancement of the voltage stability for practical power systems. With the theory of the normal forms of diffeomorphism, this paper proposes a new method to solve this problem. The proposed method makes use of the nonlinear participation factors, in which the nonlinearity of power systems can be taken into consideration. As a result, the most suitable location where the SVC should be used in power system can be determined, even for the cases in which the system is characterized with strong nonlinearity. In order to show the effectiveness of the proposed method, the New England 39-bus power system with SVC is used as an example. Calculation results show that with the SVC located at the place where the proposed method determined, the voltage stability is considerably enhanced. The steady-state voltage stability index and the time domain simulation results verify the effectiveness of the proposed method. Index Terms--Nonlinear system control, normal forms of diffeomorphism, participation factor, power system, static VAR compensator (SVC).

An optimal coordinated voltage controller (OCVC) is developed based on the spirit of model predictive control (MPC) method. The OCVC consists of three components, namely a predictor, a control candidate pool, and a selector. It has been used in secondary voltage control (SVC) to coordinate dissimilar control actions at different geographical locations in order to maintain desired voltage profiles in a global sense in emergencies. A single-stage Euler state predictor (SESP) is utilized, based on the system model, to predict voltage performance under selected control actions; the selection of the optimum control action from the pool is a complex optimization problem that is achieved by a pseudogradient evolutionary programming (PGEP) technique. Simulation results on a six-bus benchmark system and the New England 10-generator-39-bus system are given to show the potential of this method for online usage. Index Terms--Coordinated voltage control, model predictive control, pseudogradient evolutionary programming, secondary voltage control.

This paper is concerned with an investigation of a methodology using intelligent learning techniques based on system measurements to construct power system load models alongside with distribution network reduction. An comprehensive load model is proposed to represent the loads in an area of a power system. A population diversity-based genetic algorithm (GA) is developed to obtain the structure and parameters of the load model. Simulation results on a five-bus power system and an IEEE 30-bus power system are given to show the potential of this new methodology of power system modeling. Index Terms--Genetic algorithm, load modeling, network reduction, population diversity, power system.

The micro superconducting magnetic energy storage system is becoming a powerful tool for application in power systems. Nowadays, devices include active shielding systems instead of passive ferromagnetic shields. This calls for sophisticated analysis and design techniques able to provide satisfactory performance in terms of stored energy efficiency, reduced stray field, and/or minimal superconductor's volume. In this paper, the features of an active shielding system using multiple parallel solenoid configurations for superconducting magnets are analyzed and the results of their corresponding stray fields are compared. Two optimization strategies are briefly presented. The results using the proposed optimization strategies for magnet systems of energy capacity of 1 MJ, 5 MJ, and 10 MJ are given, respectively. Index Terms--Actively shielding, multiple parallel solenoids, optimized design, superconducting magnetic energy storage (SMES) system.