PDSR in Phase Angle Space and SPM Based Security Monitoring of Power Systems

Abstract

As the node power is controllable, the traditional dynamic security region (DSR) is defined on power injection space. The phasor measurement unit (PMU) can measure and transfer the state variables (phase angles) of power system synchronously. How to make full use of the synchronized phasor measurement (SPM) in the security monitoring, protection and control of power system is a challenging research task. In this paper, we presented the concept of practical dynamic security region (PDSR) in phase angle space. A study on PDSR of power systems shows that critical points satisfying transient stability in angle space can still be described by one or a few critical hyper- planes. With the PDSR in the node angle space, a concise expression to calculate the transient stability margin of a current operation point in each direction in node angle space is suggested. Besides, this paper suggested an approach to acquire the PDSR in low-dimensional angle space based on dynamic equivalence of transient stability and a method to select appropriate locations for partially equipping PMU, which provide an innovative way of making use of the PMU information to carry out dynamic security monitoring of power systems.