Search

This paper describes the application of proposed under-frequency load shedding scheme with dynamic D-factors, i.e., load frequency and voltage dependent coefficients, of various dynamic load models to Taiwan power system. The load models adopted are 1) a single-motor dynamic model, 2) a two motor (one small and one large) dynamic model, and 3) a composite (static and dynamic) model. First, the dynamic D -factor values of these load models are determined by the actual analytical approach employed in Taiwan power system. Then, a single-machine model representing a multi-machine power system is utilized for validating the proposed load shedding scheme with derived dynamic D-factor values. Finally, time simulation results of load shedding applied to various load models are compared with field measurement data, which are obtained from Taiwan power system in the case of three-phase short circuit fault, to evaluate the effects of different load models on the proposed load shedding scheme, based on the restoration of system frequency. [ABSTRACT FROM AUTHOR]

An emergency dispatch strategy (EDS) is proposed as a power system operational support tool following a transformer malfunction. First, a revised model based on IEEE C57.91 provides a method to calculate the remaining life of a transformer from the data of current load and elapsed life. Second, the life function and the constraints of transformers and the system are constructed to formulate the dispatch model. Finally, a realistic test case based on the Taiwan power system is used to demonstrate the practical applications of the EDS method. The results, when compared with those obtained using the traditional balance loads method (BLM), indicate that the EDS method is beneficial because power operators would have more time to replace a damaged transformer and successfully defer a power outage. [ABSTRACT FROM AUTHOR]

Deals with a study which investigated the impact of load models on an unstable low frequency oscillation damping through the eigenvalue analysis approach tested in the power system of Taiwan. Kinds of system-wide load models; Description of the study system; Application of power system stabilizers.

Restructuring of power system stresses the need for economic and reliable generation of power. Therefore generating units should be committed considering fuel cost and reliability level of the system. This necessitates the need for multi-objectives to be met in a unit commitment problem (UCP). Since the above objectives are conflicting in nature, a novel methodology employing optimal deviation based firefly algorithm tuned fuzzy membership function is applied to multi-objective unit commitment problem (MOUCP). The ON/OFF status of the generating units is obtained by binary coded FF whereas the sub-problem economic dispatch (ED) is obtained by real coded FF. Here the conflicting functions are formulated as a single objective function using fuzzy weighted optimal deviation. The fuzzy membership design variables are tuned using real coded FF; thereby the requirement of expertise for setting these variables are eliminated. The proposed methodology is validated on 100-unit system, IEEE RTS 24-bus system, IEEE 118-bus system and a practical Taiwan Power (Taipower) 38-unit system over a 24-h period. Effective strategy on scheduling spinning reserve is demonstrated by comparing its performance with other methods reported in the literature. [ABSTRACT FROM PUBLISHER]

Introduces an application program based on an automated mapping /facilities management geographic information system (AM/FM/GIS) to provide information expectation, load forecasting and power flow calculation capability in electric power distribution systems in Taiwan. Defects of the transformer load management (TLM) program based on AM/FM/GIS used by Taipower; Measures done to improve the defects of the TLM program.

Presents a study which proposed an approach based on neural network for the hydroelectric generation scheduling with pumped-storage units at Taiwan power system. Purpose of hydroelectric generation scheduling; Description of the problem; Overview of the neural network approach; Hydroelectric generation scheduling using noise annealing neural network.

This letter presents a simple criterion for reviewing balanced three-phase fault and unbalanced ground-fault current using the ratio of zero sequence impedance to positive sequence impedance as seen from the fault location, which can be employed to enhance the power system design and protection. The method has been verified by real power systems in Taiwan with satisfactory results. [ABSTRACT FROM AUTHOR]