Distribution Distribution State Estimation Of Research And Application

Distribution system is one of a tache of power system that facing largeness user. With the improvement of reliability and quality, Distribution Automation has been a general trend. Advanced Application Software is an important component of Distribution Automation System that plays great part in guaranteeing the safe and economical operation of the system. State Estimation is an important component of Advanced Application Software. It uses breaker state, measurement data and pseudo-measurement data provide by load forecasting to detect and identify bad data, and then estimate completed, consistent and believable real-time network state. Afterwards State Estimation provides reliable and comprehensive real-time operation mode to other application software of PAS.The characteristic of distribution system make the State Estimation different from ESM. However the basic principle is still Least-square. So far, distribution State Estimation has already many algorithms, but these algorithms all have shortcomings, such as complex programming, weak in dealing with measurement or being bad in convergence. This paper presents a new modified approach, which is based on branch current and measurement transformation. This approach uses branch current as state variable, and brings current magnitude measurement to algorithm. At first, we get state variable (brunch current) by analyzing system network, then get node voltage by afterward. This algorithm does not need form matrix, saves memory, and calculates quickly. This algorithm is feasible and efficient by testing with IEEE 12 nodes system.A network reduction method used in distribution state estimation is proposed in this paper .This method is based on the Branch-current-based state estimation .Using the reduced model in distribution state estimation soft can improve the performance of the SE in the real-world applications. This method is reliable and practical after testing with IEEE 36 nodes system.