Current sensitivity based OPF framework for active distribution network

Abstract

Proliferation of distributed energy resources (DERs) and proactive consumers has mooted over the pre-existing pricing mechanisms for active distribution networks (ADNs). This entails the need for a pricing mechanism in conjunction with cost-effective ADN operations. Locational marginal price (LMP) is a well-established pricing mechanism of the day-ahead wholesale market in most countries and provides economic signals and incentives to market participants. However, the alternating current optimal power flow (ACOPF) model (being non-deterministic polynomial-time hard) has inherent complexities and convergence issues. Besides, the approximations involved in its implementation for transmission networks may not be applicable to ADN due to their technical and structural differences. Hence, a distribution LMP (DLMP) model is indispensable for the evolving ADN. This paper proposes a network-dependent sensitivity-based branch-flow quadratic OPF model for evaluating active and reactive power DLMPs of ADNs. The DLMPs are calculated using the sensitivities and dual variables of the OPF model, which consist of incremental costs for energy, loss, congestion, and voltage components. These signals would offer an equitable price for each DER, accounting for their contribution to network conditions. The efficacy of the proposed model has been elucidated on the 33, 69, 118, and 141-node ADNs, and the results are compared with five state-of-the-art models.

Keywords

• Active distribution network
• Current sensitivity
• Distributed energy resources
• Distribution locational marginal price
• Optimal power flow