Efficient Centralized Economic Dispatch in AC/DC Interconnected Power Systems Considering Bilateral Contracts Supported by FTRs and Transmission and VSC Losses

Abstract

This paper presents a formulation for performing economic dispatch (ED) in AC/DC interconnected power systems (AC/DC-IPS). Its main feature is that it uses a generalized model for power transfer distribution factors (PTDF) in such a way that its application is straightforward for AC power systems connected in either series or parallel to DC power systems. Additionally, a piecewise linear (PWL) approach is used to modeling the cost curves of the generation units and transmission losses of the entire AC/DC-IPS, comprising voltage source converters (VSC) for AC/DC links. The losses of these elements were evaluated using a linearized second-order function of the reactor current. To achieve acceptable operation of the VSCs, the control functions of programmed flow, voltage, and angular reference are enclosed in our formulation, and based on these features, a search algorithm to find ED areas is proposed, to obtain the minimum cost centralized ED for each of these areas. Moreover, bilateral contracts between producers and consumers supported by financial transmission rights (FTRs) are included in our developed model. The performance of this ED model is illustrated by two examples, concluding that our proposal is attractive for incorporation into the ED solution problem for AC/DC-IPS.