Coordinated Voltage and Reactive Power Control Strategy with Distributed Generator for Improving the Operational Efficiency

Abstract

-This study proposes a voltage and reactive coordinative control strategy with distributed generator (DG) in a distribution power system. The aim is to determine the optimum dispatch schedules for an on-load tap changer (OLTC), distributed generator settings and all shunt capacitor switching on the load and DG generation profile in a day. The proposed method minimizes the real power losses and improves the voltage profile using squared deviations of bus voltages. The results indicate that the proposed method reduces the real losses and voltage fluctuations and improve receiving power factor. This paper proposes coordinated voltage and reactive power control methods that adjust optimal control values of capacitor banks, OLTC, and the AVR of DGs by using a voltage sensitivity factor (VSF) and dynamic programming (DP) with branch-and-bound (B&B) method. To avoid the computational burden, we try to limit the possible states to 24 stages by using a flexible searching space at each stage. Finally, we will show the effectiveness of the proposed method by using operational cost of real power losses and voltage deviation factor as evaluation index for a whole day in a power system with distributed generators.

Optimal Voltage and Reactive Power Scheduling for Saving Electric Charges using Dynamic Programming with a Heuristic Search Approach

“…The optimal dispatch of the control variables can be determined by employing DP [13]. Nevertheless, to determine the optimal control settings, huge search space is required with enormous computational burden [3].…”

“…A coordinated control strategy between on-load tap changers (OLTCs), DG units, and shunt capacitors in the distribution power system can be considered as a nonlinear discrete optimization problem. The control objective function of this problem is to minimize the electric charges, by considering active power losses and the receiving power factor at the point of common coupling (PCC) based on the forecasted hourly loads of each bus [13]. With the hourly power system day-ahead scheduling, the proposed method aims to find dispatch schedules for positions and DG setting and status of all shunt capacitors according to an optimization process based on the load demand and the DG output for the day ahead [11].…”

“…The second part of Eq. (1) is the demand charge of the receiving power factor penalty or incentive, which is the product of the standing charge and the power factor rate [13], as given by the following equation:…”

Combined control and power hardware in‐the‐loop simulation for testing smart grid control algorithms

“…[1, 2]. As distribution networks become more complex, more coordinated voltage control (CVC) approaches are necessary [3–8] employing novel technologies, such as storage systems, information and communication technologies (ICTs), advanced controllers and so on. In this way, distribution networks can be effectively monitored and controlled, allowing increased DG penetration.…”

Coordinated Voltage-Reactive Power Control Schemes Based on PMU Measurement at Automated Substations

“…Voltage control of distribution system is achieved by using OLTC and S.C. The OLTC and S.C keep the voltage at the substation bus constant [7][8][9].…”