Security and optimization rule-based coordinated generator simultaneous tap changing dispatch scheme for transmission voltage regulation

Abstract

To regulate transmission network voltage within statutory limits, transmission system operators (TSO) can issue instructions to the grid synchronized generators to simultaneously change their transformer tap positions, and these instructions are normally preceded by advance notice and executed at the required time. This operation action is known as “Simultaneous Tap Change Dispatch” (STCD).This paper presents a security and optimization rule-based generator Simultaneous Tap Change Dispatch (STCD) scheme, which aims to maintain system wide-area voltage stability through effective and fast voltage regulation, and to minimize the total amount of reactive power utilization; thus, indirectly reduces the line losses. Technical implementation of the proposed STCD is discussed, and the costs of MVar utilization by the STCD is compared with the employment of new shunt reactors. The proposed STCD scheme is validated in a DIgSILENT Power Factory platform to simulate a real regional system model in Great Britain (GB). And, the effectiveness of STCD scheme in transmission voltage regulation, generator MVar optimization, and operational security are verified by comparing to the baseline (a system with uncoordinated schemes).