讲坛题目：Protection and Control Systems and Wide Area Schemes
Title: Protection and Control Systems and Wide Area Schemes
Power system state estimation is the enabler of energy management system (EMS), and plays a vital role in power system protection and control. The state estimator is responsible for providing accurate data for the EMS so that it can work so that it can work reliably. To be more specifically, the functions of the state estimator include making the optimal estimate based on a redundant set of measurements (which is true for transmission networks) with certain levels of errors, detecting and identifying bad data, sudden load changes, unreported topology changes and even cyber attacks with false data injection. Classical state estimators have relied on the measurements provided by Supervisory Control and Data Acquisition (SCADA) system to estimate the states. Recently, with the advent of synchronised measurement technology (SMT) facilitated by a new type of measurement device called phasor measurement unit (PMU), state estimator is expected to substantially improve its performance with much higher estimation accuracy and even real-time monitoring of the power system. However, challenges are also established to improve the state estimators so that they can work with SMT and take its full benefits. This lecture will present an introduction of power system state estimation in transmission networks, including details of the functions of the state estimator as given above and a story of how state estimators evolve with the advent of SMT.
Title: Distribution System State Estimation
The key component of DMS (Distribution Management System) is state estimation function. The task of state estimation is to provide an optimal estimate of the complex bus voltages in the entire distribution system by using the set of available measurements. Distribution system state estimation currently employs conventional real-time measurements from SCADA (Supervisory Control and Data Acquisition), which are typically available at the high-to-medium voltage substation. The rest of the distribution network is poorly monitored what causes low redundancy. A large number of pseudo measurements must be provided to achieve a full network observability. Pseudo measurements are usually based on daily profiles from historical database or weather forecast. Consequently, they are characterized by limited accuracy which affects the quality of state estimates. Modern distribution networks are expected to include PMUs (Phasor Measurement Units) in the future, which can increase the accuracy level of state estimation or even pave the path to the real-time state estimation. Unlike transmission networks, distribution networks consist of radially supplied short, untransposed and unbalanced overhead power lines/underground cables. These are characterized with high R/X ratio and could be single-, two- or three-phase. Therefore, the other challenge is development of three-phase state estimation algorithms which are essential for distribution networks. This lecture will present the challenges and solutions for state estimation at distribution level, analyse different types of state estimation algorithms, explain basic functions that state estimator typically includes (topology processor, bad data processing), as well as benefits of employing PMUs in the future distribution networks.
主 持 人：亚游国际游戏官网副研究员 蔡德宇