Decentralized Control of Multiterminal HVDC Systems Embedded in AC Networks

摘要

A continuations approach to eigenvalue assignment through dynamic decentralized output feedback is developed. The underlying system model is the Component Connection Model. In such a context it is possible to parameterize the connection information and derive a differential equation whose solution trajectory characterizes appropriate decentralized feedback gains. The design technique is used to investigate the pole placement problem in a two-machine, infinite bus, two-terminal HVDC system. Joint current modulation at the rectifier and voltage modulation at the inverter is utilized. It is shown by eigenvalue analysis and analog simulation that this modulating strategy is more effective than decentralized current modulation alone: greater flexibility in assigning the eigenvalues, smaller dc current swings. Finally the technique is used in the design of decentralized power modulation in multiterminal HVDC systems. Decentralized output feedback gains are computed to reassign specified eigenvalues so that stability margins and dynamic responses are improved. A computer simulation of an integrated ac/dc power system demonstrates resulting control performance for typical disturbances. Comparisons are made with centralized modulation and several designs with limited communications. The nonlinear coordination problem of the power modulation is briefly addressed. (ERA citation 09:013642)