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Title: Effect of load models on ac/dc system stability and modulation control design

Journal Article · · IEEE Trans. Power Syst.; (United States)
DOI:https://doi.org/10.1109/59.193810· OSTI ID:6116421

This paper investigates important aspects related to the effect of load models on the modulation control design and stability of a modulated ac/dc system. Static load is modeled as a nonlinear function of load bus voltage and dynamic load is modeled by an equivalent induction motor. DC power and reactive power modulations are considered for the modulation controllers. A method for eigenvalue sensitivity calculation is developed to predict the effect of load characteristics on the system stability. Eigenvalue sensitivity and simulation results show that static and dynamic load characteristics may have a considerable effect on the system stability. The impact of static and dynamic load models on the modulation controller gains obtained via optimal control theory is examined and it is shown that load models may have a marked influence on the controller gains. It is also shown that there are specific situations where the choice of load model can make a difference in system stability prediction. In particular, simulation with constant active power and induction motor loads shows system instability when the reactive power modulation controller is designed assuming constant impedance load.

Research Organization:
West Virginia Univ., Electrical and Computer Engineering Dept., Morgantown, WV (US)
OSTI ID:
6116421
Journal Information:
IEEE Trans. Power Syst.; (United States), Vol. 4:2
Country of Publication:
United States
Language:
English