Power System Small-Signal Stability as Affected by Grid-Connected SmartPark

Large-scale smart charging stations can effectively satisfy and control the charging demands of tremendous plug-in electric vehicles (PEVs). But, simultaneously, their penetrations inevitably induce new challenges to the operation of power systems. In this chapter, damping torque analysis (DTA) was employed to examine the effects of the integration of smart charging station on the dynamic stability of the transmission system. A single-machine infinite-bus power system with a smart charging station that denoted the equivalent of several ones was used for analysis. The results obtained from DTA reveal that in view of the damping ratio, the optimal charging capacity is better to be considered in the design of the smart charging station. Under the proposed charging capacity, the power system can achieve the best maintained dynamic stability, and the damping ratio can reach the crest value. Phase compensation method was utilized to design the stabilizer via the active and reactive power regulators of the smart charging station respectively. With the help of the stabilizers, damping of the system oscillation under certain operating conditions can be significantly improved, and the power oscillation in the tie-line can be suppressed more quickly.