Due to their versatility of control, and their ability to be used in dc grids, the Voltage Sourced Converters (VSC) are rapidly gaining popularity in HVDC Transmission. However, certain instability behaviours can arise with their use. This talk will start with steady-state behaviours such as voltage-stability violation initiated by weakening ac system strength. Then it will present small signal instability behaviour resulting from controller gains, focusing particularly on the parameters of the phase locked loops. Most emerging VSC converters will be of the multi-level modular (MMC) type. Finally the talk will discuss a dynamic phasor based analysis of harmonic instabilities that involve only the internal components of the MMC such as at its capacitors and arm reactors, and which are not easily observable in the ac side network. Some solutions to mitigate these instabilities will also be presented.
Prof. Aniruddha Gole is Distinguished Professor and NSERC Industrial Chair in Power Systems Simulation at the Department of Electrical and Computer Engineering, at the University of Manitoba. He is an alumnus of IIT Bombay, having graduated with a B.Tech. (EE) degree in 1978. He has over 35 years’ experience in the development of modelling tools for power networks incorporating power-electronic equipment such as HVDC and FACTS converters. He is one of the original developers of the widely used PSCAD/ EMTDC simulation program. Dr. Gole has also made important contributions to the development of the real-time digital simulator RTDS from RTDS Technologies of Winnipeg, Canada. For his contributions to the modelling of Flexible Ac Transmission System (FACTS) devices, Dr. Gole was awarded the IEEE PES Nari Hingorani FACTS Award in 2007. Dr. Gole is a Fellow of the IEEE, a Fellow of the Canadian Academy of Engineering and is a Registered Professional Engineer in the Province of Manitoba, Canada.