Y. Lai’s scientific contributions

It is critically important to maintain long-term adequacy for power systems. With market rules, bidding strategies and investment strategies of market participants being represented as experimental environment, this paper studies long term dynamics of generation capacity adequacy by using dynamic simulations of investment market interacted with power market. Mechanisms of long term oscillation of the generation capacity adequacy are explored. The influences of generation capacity construction delays, surveillant approval to augment new capacity and game strategies of the investors on the oscillation cycle, swing magnitude and market concentration index are investigated, which is helpful to keep power market and power system healthy.

The available generation capacity can be divided into three sections, i.e. static inadequacy, dynamic risk adequacy and dynamic adequacy. Margins of static adequacy and dynamic adequacy are defined respectively, the effects of static and dynamic disturbances could be quantitatively analyzed. Risks of generation capacity are dealt with in a 3-D space consisting of static adequacy margin, dynamic adequacy margin and cost. The risk-optimized uninterruptible load can be estimated by treating interruptible loads as one kind of emergency generation reserve. Simulations show the validity of the presented method.

Decision-making on operational reserve capacity has been guided by deterministic criteria in most of cases, or by probabilistic algorithms in a few researches. Both kinds of approaches don't consider the loss resulting from generation inadequacy and cannot coordinate different kinds of reserves. Risk is a computable quantity which can be used to integrate the security with economics into a formal decision-making algorithm. Based on risk management, an optimal decision-making method is presented for reserve capacity, which coordinates various kinds of reserve resources including instantaneous and non-instantaneous generation capacities as well as interruptible loads. Simulations show that the presented method can balance the supply-demand reliably as well as cost effectively.