A Study on the Relationship between Probabilistic and Deterministic Reliabilities in Korea

This paper introduces the characteristics of relationship between probabilistic reliability (LOLE; loss of load expectation) and deterministic reliability (SRR; supply reserve rate) for 2008 and 2010 years in Korea power system. Korea power system has been using the loss of load expectation criterion (0.5 days/year) to determine the adequacy of installed capacity (ICAP) requirement. The criterion is that load shall not exceed the available capacity, on the average, more than five days in ten years. In order to identify the relationship, this paper describes an effective algorithm for evaluating probabilistic reliability and calculating the production cost for all the generators in the system using fast hartley transform (FHT). The FHT has been used in convolution process. Convolution process is not performed in the capacity domain. But original function is transformed into the frequency domain by FHT and convolution process is performed in this domain. The FHT is as fast as or faster than using FFT because the transformed function using FHT has real numbers, while the transformed function using FFT has complex numbers. The convolution becomes quite simple. In here, the scheduling of pumped-storage plants and hydro plants with energy constraints is considered. To do this, the de-convolution formula is newly derived. Also, the models which includes multi-block by loading of units to equal marginal cost levels in an economic dispatch mode and multi-state by the partial loading caused from de-rates are considered. In future, the proposed method will be useful for the reliability pricing model (RPM), which is the capacity construct to implement forward procurement of generating capacity requirement recognizing its locational value.