Optimization approach to unified AC/DC power flow applied to traction systems with catenary voltage constraints

Abstract

This paper presents two innovative contributions related to the combined AC/DC power ow in railway power supply systems (RPSS). First, most of the power ow equations (the linear ones) are expressed in a compact matrix form by using graph theory based protocol. Such approach simpli- es the statement of the uni ed power ow problem and allows the train motion to be modeled without varying the system topology. Second, the problem is formulated as an Optimization Problem (OP) instead of using the non-constrained power ow approach. This technique allows the authors to simulate the e ect of trains regenerative braking, considering system con- straints such us the catenary voltage limit, which determines the amount of available regenerated energy injected to the network, and burned through the resistors