Planning and operation of dynamic energy storage for improved integration of wind energy

In this paper, a power-electronic based storage device is presented, which can control both active and reactive power at the point of connection. The device is based on a STATCOM and a Battery Energy Storage System (BESS). The device is utilized to maintain the system stability under contingency operating condition with high wind generation in the system. The objective of this paper is to demonstrate the operational and economical benefits obtained with this dynamic storage device. First, the paper identifies the system problems under high level of wind generation in the Tehachapi area of Southern California Edison system. Steady state and dynamic studies were conducted to evaluate different system contingencies and their impact. A mitigation method was suggested using the energy storage device to sustain the system stability under N-1 contingency conditions. A sensitivity analysis was conducted to evaluate the required battery size and its reactive capability. The analysis also demonstrates that the BESS can help to dispatch the wind farms in the area during steady state. The BESS can be used to reduce the local wind generation curtailment under high local wind generation and low local system load due to N-1 contingency constraints. Finally, an economic analysis is conducted to calculate the return on investment for BESS.