Harmonics and instabilities in switching circuits
- Univ. of Wisconsin, Madison, WI (United States). Coll. of Engineering
Over the last couple of years there has been significant activity in the development of Flexible AC Transmission Systems (FACTS). Much of this work has been directed towards advanced series compensation (ASC) systems based on a Thyristor Controlled Reactor (TCR) connected in parallel with a fixed capacitor. This results in a controllable series impedance element for use in transmission systems. FACTS devices generate harmonics which interact with the transmission system causing voltage distortions. These distortions can change the operation of such circuits. The authors have found new instabilities in both FACTS and static VAR circuits in which switching times change suddenly, or bifurcate as a system parameter varies slowly. The switching time bifurcation instabilities are explained and their mechanisms are illustrated by both analysis and simulation. The TCR is a periodically operated, nonlinear circuit which may be studied using a Poincare map. The Poincare map is computed and a simple formula for its Jacobian matrix is derived. This formula which describes the stability of the steady state periodic operation of the circuit is used to demonstrate that conventional bifurcations do not occur in this TCR example. The harmonic coupling solution method as developed by Bohmann and Lasseter has been extensively used to compute the steady state solutions of the TCR circuits. In this method, Fourier techniques are used to calculate the system harmonics. By expressing the TCR voltage and current as a Fourier series, a TCR harmonic admittance matrix is constructed and incorporated into a power system providing a general method of computing the power system harmonics. The authors have extended this method to single phase line commutated converters and shown how much circuit may have highly nonlinear and unexpected behavior.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (United States); Wisconsin Univ., Madison, WI (United States). Coll. of Engineering
- Sponsoring Organization:
- EPRI; Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 7368939
- Report Number(s):
- EPRI-TR-102317
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AC SYSTEMS
SWITCHING CIRCUITS
HARMONICS
CALCULATION METHODS
COMPUTERIZED SIMULATION
DATA ANALYSIS
DESIGN
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
INSTABILITY
MATHEMATICAL MODELS
POWER DISTRIBUTION SYSTEMS
POWER SUBSTATIONS
POWER TRANSMISSION
PROCESS CONTROL
PROGRESS REPORT
STEADY-STATE CONDITIONS
CONTROL
CURRENTS
DOCUMENT TYPES
ELECTRONIC CIRCUITS
ENERGY SYSTEMS
OSCILLATIONS
POWER SYSTEMS
SIMULATION
240201* - Power System Networks
Transmission & Distribution- AC Systems- (1990-)