Active and Reactive Power PSCOPF for Mixed AC- HVDC-Systems

By current security definitions, the N-1 security of AC-HVDC-systems has to be evaluated separately for both the AC- and the HVDC-system, whilst the Voltage Source Converter (VSC) technology ensures a controlled power exchange between both systems. Under this premise, new system operation strategies are possible like a combined N-1 security definition. Critical contingencies to be respected in this case comprise outages of AC and HVDC lines and VSC. This paper proposes an advanced Preventive Security Constrained Optimal Power Flow (PSCOPF). The algorithm adapts the VSC set-points comprising the active power and DC node voltages. The PSCOPF algorithm is based on a Differential Evolution algorithm whose performance has been further improved by a sophisticated contingency handling technique.