MILP model for volt-var optimization considering chronological operation of distribution systems containing DERs

Abstract

This paper presents a mixed-integer linear programming model for volt-var optimization considering the chronological operation of distribution systems containing distributed energy resources (DERs). The proposed model describes the operation problem of capacitor banks (CBs) and voltage regulators (VRs), and it is further based on the steady-state operation during each time interval contained in typical scenarios of distribution systems. A procedure using a K-means clustering algorithm is used to select the scenarios, thus preserving the simultaneity and chronological combination of different loads and DERs. According to the formulation that we developed, the regulation devices become sensitive to downstream load variations, since we use explicit current variables to control automatic CBs, and since we include means to compensate voltage drops along distribution lines in the control of VRs. The model is validated by comparing the results obtained during several tests of two typical cases with those obtained through nonlinear power flow. The typical case studies presented in the paper highlight the good agreement between the results obtained with the linearized model and with power flow method; further, the practical results confirm that the use of typical scenarios allows representing different levels of loads and DERs, while keeping the validity and performance of the proposed model.

Efficient Day-Ahead Scheduling Voltage Control Scheme of ULTC and Var of Distributed Generation in Distribution System

“…Further, many studies deal with the nonlinear optimization problem (NLP), and they attempt to solve this problem through various optimization techniques such as using genetic algorithms, mixed integer NLP, fuzzy algorithm, etc. [21][22][23][24]. Most studies related to VVO have been formulated as optimization problems to satisfy various objectives such as economic, loss, and operation problems using the predicted profile of load and DGs, and the solutions are derived using various optimization methods.…”

Multi-Time-Scale Volt/var Control in Distribution networks with the Coordination of PV Inverters and Capacitor Banks

“…A successive linear programming method is used in [5] to linearize the VVO problem based on voltage sensibilities, and the optimal dispatch for PV inverters is given during the considered days. In [6], a scenario method is applied to model the varying loads and distributed energy resources in VVO, and steady-state device operations can be appropriately obtained in each 1-hour time step.…”

Whale Optimization Algorithm Based Optimal Operation of Power Distribution Systems

“…Volt-Var optimization is a common method for operating inverters and capacitors [1]- [10]. For example, the article [1] shows the performance of volt-var controlled PV inverters using the circuit reduction method.…”

“…In the paper [6], voltage control based on local optimization using battery storage in residential buildings was studied, and in the paper [8], PV control was used. A chronological operation based volt-var optimization for daily scenarios with piecewise linearization was shown in [10]. In the paper [9], reliability was enhanced using optimal operation of distributed generation.…”

“…10) where Can i,j shows the values of the control values in the allowed ranges. The candidate matrix consists of k different candidate solution sets, each consist of d variables.…”