Influence of measurement uncertainty propagation in current-channel-selectable multi objective optimal phasor measurement unit placement problem

This paper proposes current-channel-selectable multi objective optimal Phasor Measurement Unit (PMU) placement problem with measurement uncertainty propagation. In proposed Multi Objective Optimal PMU Placement (MOOPP) problem, allocation of the current phasor channel of the PMU can be selected for reducing the total PMU placement cost. However, in practice, uncertainty of measurement makes the estimation error bigger because of use of pseudo measurement by the current channel selection. This paper proposes the optimal PMU placement method considering minimizing both the total PMU placement cost and the state estimation error with uncertainty propagation. The result of the numerical experiment demonstrates the advantage of considering the measurement uncertainty propagation, compared to the conventional method which ignores it, in IEEE New England 39-bus test system. As a result, the proposed method obtained a better Pareto solution compared to the conventional methods because of consideration of measurement uncertainty in the pseudo measurements

Optimal PMU Placement for Power System Dynamic State Estimation by Using Empirical Observability Gramian

In this paper the empirical observability Gramian calculated around the operating region of a power system is used to quantify the degree of observability of the system states under specific phasor measurement unit (PMU) placement. An optimal PMU placement method for power system dynamic state estimation is further formulated as an optimization problem which maximizes the determinant of the empirical observability Gramian and is efficiently solved by the NOMAD solver, which implements the Mesh Adaptive Direct Search (MADS) algorithm. The implementation, validation, and also the robustness to load fluctuations and contingencies of the proposed method are carefully discussed. The proposed method is tested on WSCC 3-machine 9-bus system and NPCC 48-machine 140-bus system by performing dynamic state estimation with square-root unscented Kalman filter. The simulation results show that the determined optimal PMU placements by the proposed method can guarantee good observability of the system states, which further leads to smaller estimation errors and larger number of convergent states for dynamic state estimation compared with random PMU placements. Under optimal PMU placements an obvious observability transition can be observed. The proposed method is also validated to be very robust to both load fluctuations and contingencies.Comment: Accepted by IEEE Transactions on Power System

A Framework for Phasor Measurement Placement in Hybrid State Estimation via Gauss-Newton

In this paper, we study the placement of Phasor Measurement Units (PMU) for enhancing hybrid state estimation via the traditional Gauss-Newton method, which uses measurements from both PMU devices and Supervisory Control and Data Acquisition (SCADA) systems. To compare the impact of PMU placements, we introduce a useful metric which accounts for three important requirements in power system state estimation: {\it convergence}, {\it observability} and {\it performance} (COP). Our COP metric can be used to evaluate the estimation performance and numerical stability of the state estimator, which is later used to optimize the PMU locations. In particular, we cast the optimal placement problem in a unified formulation as a semi-definite program (SDP) with integer variables and constraints that guarantee observability in case of measurements loss. Last but not least, we propose a relaxation scheme of the original integer-constrained SDP with randomization techniques, which closely approximates the optimum deployment. Simulations of the IEEE-30 and 118 systems corroborate our analysis, showing that the proposed scheme improves the convergence of the state estimator, while maintaining optimal asymptotic performance.Comment: accepted to IEEE Trans. on Power System

Reliably optimal PMU placement using disparity evolution-based genetic algorithm

Phasor Measurement Units (PMUs) are an important component in Wide Area Protection (WAP)- based operations in power systems. It is needed that a certain placement scheme of PMUs is suggested if power system scale gets larger. The optimal placement of PMU in power systems has been considered and formulated in order to reduce the number of installed PMUs while accomplishing a desired level of reliability of observation. Optimal PMU Placement (OPP) problem as the combinatorial optimization problem has been formulated to determine the minimum PMU location in the power system. In this paper, Disparity Evolution-type Genetic Algorithm (DEGA) based on disparity theory of evolution is applied. Genetic Algorithm (GA) is employed for the purpose of comparison with DEGA. The optimization model is solved for IEEE 118 standard bus system. DEGA can find better placement suggestion compared with GA because of the nature of evolution that models the double spiral structure of DNA to hold the diversity of population

Heuristic Method for Optimal Placement of Phasor Measurement Units (PMUs)

The phasor measurement units (PMUs) are very important tool for monitoring and control the power system. PMUs give real time, synchronized measurements of voltages at the buses and also current phasors which are incident to those buses where these PMUs are located. It is unnecessary and impossible to place PMU at each bus to estimate the states because high cost of PMUs and also the cost of communication facilities. It is necessary to find out the minimum number of PMUs to entire power system observable. The optimal placement of PMUs (OPP) problem solved by various techniques such as mathematical programming, metaheuristic techniques. The recently some heuristic optimization technique proposed to determine the minimum number of PMUs for various systems should be completely observable. This optimal PMUs placement (OPP) problem is pure binary optimization problem. A topological observability based three stages optimal PMU placement technique is proposed for solving this problem. For topological observability a set of minimum PMUs is required to make the system completely observable. It is assumed that there are strategic buses in every system using that the PMU placement becomes an easy task. The proposed method tested on standard IEEE bus systems and compared the results of the proposed method to the previously methods