Shufeng Dong

Enhanced Security-Constrained OPF With Distributed Battery Energy Storage

This paper discusses how fast-response distributed battery energy storage could be used to implement post-contingency corrective control actions. Immediately after a contingency, the injections of distributed batteries could be adjusted to alleviate overloads and reduce flows below their short-term emergency rating. This ensures that the post-contingency system remains stable until the operator has redispatched the generation. Implementing this form of corrective control would allow operators to take advantage of the difference between the short- and long-term ratings of the lines and would therefore increase the available transmission capacity. This problem is formulated as a two-stage, enhanced security-constrained OPF problem, in which the first-stage optimizes the pre-contingency generation dispatch, while the second-stage minimizes the corrective actions for each contingency. Case studies based on a six-bus test system and on the RTS 96 demonstrate that the proposed method provides effective corrective actions and can guarantee operational reliability and economy.

Robust State Estimator Based on Maximum Normal Measurement Rate

In this paper, the concept of normal measurement rate (NMR) is defined based on the theory of uncertainty in measurement and a robust state estimator named maximum normal measurement rate (MNMR) estimator is proposed. Comparison is made between the MNMR estimator and other robust estimators. The robustness and precision of this estimator is tested with the IEEE 14-bus, 30-bus, and 118-bus systems. Simulation results show that the MNMR estimator is effective in identifying bad data and is also time efficient.

Probabilistic Load Flow Based on Generalized Polynomial Chaos

An analytical method based on generalized polynomial chaos (gPC) is proposed for probabilistic load flow (PLF). The method preserves the nonlinearity of power flow equations whose rectangular formulations are adopted to facilitate the gPC expansion. The feasibility of the method is demonstrated by case studies from a 9-bus system.

Decentralized synergetic dispatch considering operating risk of interconnected power systems

Locational marginal price (LMP) is a market-pricing method used to determine optimal dispatch of interconnected power systems. In order to take systems operating risk into consideration, a modified risk-based LMP (RLMP) calculation method is given in this paper. We design a risk-based decentralized synergetic dispatch pattern in electricity market environment to avoid the drawbacks of centralized dispatch. A double-layer optimization model is considered. In the lower level, local dispatch centers operate autonomously to arrange their own generation plans and guarantee the risk constrains. In the upper level, the main dispatch center compares the updated RLMP curves sent from the lower level and figures out ideal power flows on tie lines to achieve the highest social welfare. Three different synergetic strategies for various system structures are respectively demonstrated. The validity and effectiveness of the proposed approach in interconnected power systems are illustrated on a 6-bus system and a three-area 42-bus system.

Software implementation of risk-based dispatch

In this paper, the implementation of a risk based dispatch system (RBDS) for identifying, assessing and controlling system operational risk associated with weather & natural disasters is illustrated. Firstly, a risk-based dispatch framework is presented, then SOA based software architecture of RBDS is discussed. Practical experiences show RBDS could be a useful decision-making tool for operators.

Probabilistic load flow by generalized polynomial chaos method

The probabilistic load flow (PLF) problem is solved by a new approach named generalized polynomial chaos (gPC) method. This method combines the techniques of gPC expansion and Galerkin method and transforms the PLF equations into a set of deterministic equations. After the deterministic equations being solved by conventional methods, the means and variances of PLF random variables can be easily obtained and the probabilistic density functions of relevant variables can be estimated by Monte Carlo simulation. The load flow equations in rectangular form are adopted to avoid high order truncation errors of the expansions of PLF equations. Compared with other analytical PLF methods, this method preserves the nonlinearity of the load flow equations and hence can achieve better accuracy, which are verified by the case studies of a 9 bus system.

Cyber-Physical Power System (CPPS) reliability assessment considering cyber attacks against monitoring functions

In Cyber-Physical Power System (CPPS), cyber system and the possible cyber attacks may affect the behavior of physical system. This paper deals with the reliability impact of cyber attacks against monitoring functions to CPPS. Firstly, the monitoring function failure model considering possible cyber attacks is proposed. Secondly, the reliability impact of transmission line monitoring function failure is analyzed. Then, an improved reliability assessment method is presented for quantitative calculation of this impact. Finally, the proposed approach is simulated and analyzed on an benchmark system to verify its necessity and feasibility.

An Improved Algorithm for State Estimator Based on Maximum Normal Measurement Rate

Previous work has shown that robust state estimator based on maximum normal measurement rate is accurate and reliable. However, in the existing algorithm, the optimal solutions cannot be obtained due to the approximation of evaluation function. Besides, there are no noise-filtering effects on normal measurements. To deal with these two problems, this letter presents an improved algorithm to get a more accurate solution with higher normal measurement rate. Numerical tests on different systems show the proposed algorithm is efficient.