PWMSC Controller Design for Damping Electromechanical Oscillations

Abstract

Original scientific paperPulse Width modulated based Series Compensator (PWMSC), a newly FACTS device, can modulate the impedance of a transmission line through the variation of the duty cycle of a train of pulses with fixed frequency, resulting in improvement of system performance. In this study, a current injection model of PWMSC is proposed and incorporated in the transmission system model. The purpose of the work reported in this paper is to design an oscillation damping controller for PWMSC to damp low frequency oscillations. We have used the residue method to the linearized equations of the power system for multiple operating conditions and obtained a generalized form which is suitable for different damping controller input-output channels and therefore suitable for different control devices. The case study results show that the proposed controller is very effective to mitigate the power system critical modes of oscillation. Key words: PWMSC, Current Injection Model, Residue Method, Modal Analysis, Damping Controller.Dizajn PWMSC regulatora za prigušenje elektromehaničkih oscilacija. Pulsno-širinski modulirani serijski kompenzator (PWMSC), novi FACTS ureaj, modulira impendanciju prijenosne linije putem promjene popunjenosti niza signala s konstantnom frekvencijom, što rezultira poboljšanim svojstvima. U ovome radu predložen je model ubrizgavanja struje u PWMSC-u koji je nadodan u model prijenosa. Cilj ovoga rada bio je dizajnirati oscilatorni regulator prigušenja za PWMSC u svrhu prigušenja niskih frekvencija oscilatora. Korištena je metoda reziduala na linearizirani model energetskog sustava za različite uvjete te je dobivena općenita forma pogodna za ulazno-izlazne kanale regulatora prigušenja pogodna za različite upravljačke ulaze. Analiza pokazuje da je regulator učinkovit kod ublažavanja kritičnih oscilacija energetskog sustava.