Designing Rule for Price-Based Operation With Reliability Enhancement by Reducing the Frequency Deviation

In a deregulated power system, the independent system operator (ISO) becomes the central entity which is responsible for the reliable system operation and the real-time balancing. ISO can provide necessary functions through the market mechanism. However, the possibility of a price-based operation is suggested as well, in which time-varying price coordinates non-cooperative players´ actions. In the price-based operation, the main objectives of operation are also to keep the system frequency to the nominal value and to manage the line congestion. In terms of the frequency, the price-based operation should at least assist the frequency regulation functions by reducing the frequency deviation. For this purpose, this paper tries to present a method to reduce the frequency deviation and proposes the application of PID tuning rule to the design of price-based operation. In addition, a modified asymmetric control structure is proposed to obtain a further reduction of the frequency deviation. The performance and suitability of the designing rule are verified through simulations using the IEEE 39-bus network.