Yanbo Chen

A Seidel-Type Recursive Bayesian Approach and Its Applications to Power Systems

This letter proposes a Seidel-type recursive Bayesian approach for the power system parameter estimation. By timely using the latest probabilities calculated in the current iteration instead of the posteriori probabilities obtained in the last iteration, the proposed approach significantly enhances the efficiency and robustness of the recursive Bayesian estimation, especially in case of large noise.

Robust State Estimator Based on Maximum Exponential Absolute Value

In this paper, a robust state estimator based on maximum exponential absolute value (MEAV) is proposed by using the maximum correntropy criterion (MCC) with Laplace kernel function as the objective function of state estimation. Since the objective function of MEAV model is continuous but non-differentiable, its equivalent model is given, which is then solved based on the primal-dual interior point method. To further improve the computational efficiency, a new correction equation with much lower order is presented and the number of fill-ins in the solving process is reduced by a systematic method. Simulations based on the IEEE benchmark systems and two real grids of China demonstrate that the proposed MEAV estimator is very robust with high efficiency.

An Improved Recursive Bayesian Approach for Transformer Tap Position Estimation

In this paper, a reliable and efficient methodology based on the recursive Bayesian approach (RBA) and its improved version (SRBA) is proposed for the transformer tap position (TTP) estimation. By recursively computing the posteriori probabilities of all the tap positions of the suspicious transformer, the proposed approach can find the correct TTP reliably. Furthermore, we remarkably improve the computational efficiency of SRBA from the following aspects: 1) reducing the number of transformers to be estimated by identifying suspicious tap positions; 2) proposing a fast prediction-correction algorithm to calculate the residuals; 3) reducing the set including the correct tap position by using a heuristic method during the recursive process; 4) reducing iteration numbers by proposing a stopping criterion with solid theoretical foundation. Simulations are carried on the IEEE 14-bus system and a real power grid of China, illustrating that our methodology is reliable with high efficiency.

Reliability evaluation of the new generation smart substation considering relay protection system

The new generation smart substation has become the future development direction of substation. At present, the reliability assessment method of the new generation smart substation are based on substation system itself or relay protection system separately, without considering the comprehensive influence of these two systems, leading high reliability index obtained. Based on minimum path algorithm, this paper firstly establishes the reliability assessment model of the new generation smart substation considering relay protection system. Then, an equivalent reliability index considering the comprehensive influence of the primary system and relay protection system is proposed. Finally, the proposed model and approach are tested on a real new generation smart substation..

Analysis of technology and economy of new generation smart substation

With the development of power grid, great progress have been achieved on the integrated design, smart device manufacturing, modular distribution construction of the new generation smart substation, which are revolutionarily innovative. This paper introduces design characteristics, construction goal and functions of the new generation smart substation, key equipments and core technologies such as disconnecting circuit breaker, station area protection and control system, and analyzes the technology advantages, such as reducing footprint, shortening construction period, reducing maintenance cost, improving the reliability. Based on analytic hierarchy process and fuzzy comprehensive evaluation, a method to evaluate economic performance of substation in a whole life cycle is proposed. First, the structural model is established for the economic factor in the whole life cycle of substation. Then a comprehensive evaluation system is constructed, and the evaluation and calculation method of the factors in the system are deduced. Evaluation on a 110kV new generation smart substation shows that it could effectively reduce the substation life-cycle cost.

A Robust WLAV State Estimation Using Optimal Transformations

Works by Celik and Abur suggest a weighted least absolute value state estimation with transformations (WLAV-T) for attaining insensitiveness of state estimation (SE) to bad measurements by mitigating the effect of leverage points. To further improve its applicability, this letter proposes a systematic approach to compute the optimal rotation angles and scaling factors of the WLAV-T, deriving a robust WLAV estimation approach with optimal transformations (WLAV-OT). The proposed approach has been preliminarily tested with promising results.

Many-objective reactive power optimization using Particle Swarm Optimization algorithm based on Pareto entropy

This paper presents a many-objective reactive power optimization model which consists of minimum active power loss, minimum node voltage deviation, maximum static voltage stability and maximum power supply capability. To efficiently solve this model, a novel approach by using particle swarm optimization is proposed. This approach is called many-objective particle swarm optimization algorithm based on Pareto entropy which adopts loose Pareto dominant relationship and maps the Pareto front from cartesian coordinate system to parallel cell coordinate system, thus designing evolutionary strategies using Pareto fronts distribution entropy and entropy difference in the new coordinate system. The presented algorithm is capable to balance convergence and diversity of the approximate Pareto front. Moreover, cell dominant intensity and individual density are introduced to assess the individual environment fitness of the Pareto optimal solution, and we hereby design the selection strategy of the global best solution. Simulations based on the IEEE 14-bus systems demonstrate the effectiveness of the proposed model and the efficiency of the proposed algorithm.

Multi-objectives OPF of AC-DC systems considering VSC-HVDC integration

The existing optimal power flow (OPF) of AC-DC systems considering VSC-HVDC integration is a single-objective optimization problem. This paper proposes a multi-objectives OPF model of AC-DC Systems considering VSC-HVDC integration, which taking into account the minimum net loss, the voltage and transient stability constraints. To effectively solve the proposed model, this paper presents a mixed solving method, i.e. primal-dual interior point method for solving continuous variables and NSGA2 for solving discrete variables. Tests on IEEE benchmark systems illustrate the effectiveness and efficiency of the proposed approach.

Surrogate Modeling-Based Multi-Objective Dynamic VAR Planning Considering Short-Term Voltage Stability and Transient Stability

Transient stability and short-term voltage stability have successively attracted the attention of electric power industry. This paper proposes a novel systematic approach for dynamic VAR planning to improve short-term voltage stability level and transient stability level. The dynamic VAR planning problem is formulated as a multi-objective optimization (MOO) model with objectives including investment cost, short-term voltage stability level, and transient stability level. To reduce the complexity of the proposed MOO model, K-means clustering-based severe contingencies selection and global sensitivity analysis-based potential buses selection are employed, leading to a simplified MOO model. The combination of a surrogate modeling technique called support vector regression and the multi-objective evolutionary algorithm (MOEA) are then used to solve the simplified MOO model, considering both the accuracy of models and the optimization computation cost. This combination makes it feasible to perform multiple runs of MOEAs for weakening the effect of the MOEAs randomness to optimal results and offering more diverse Pareto-optimal solutions for decision makers. Simulations are carried on the IEEE 39-bus system and a real power grid of China, illustrating that our methodology is reliable with high efficiency.

Improved SEC model based evaluation approach for design scheme of the new generation smart substation

When evaluating a substation design scheme, the existing evaluation methods have not consider a series of uncertainty factors such as the number of faults, the cost of operation, the economic losses caused by the failure of power outages and so on in the life cycle, meanwhile, the evaluation methods of safety and efficiency in the design scheme of substation are also insufficient. In this paper, by comprehensive considering the above uncertain variables, safety, efficiency and cost of the design scheme, an uncertainty evaluation model is proposed. In the proposed model, the weight of each index is determined by entropy-weighted fuzzy comprehensive evaluation method and then the Monte Carlo simulation method is used to solve the model. The example shows that the proposed method is effective for the new generation smart substation comprehensive assessment, so as to provide guidance for the planning and construction of the new generation smart substation.