Stabilizing the power supply in microgrid using sensor selection

Abstract

Integration of distributed energy resources (DERs) into microgrid makes power supply more reliable and reduces the cost. However, the connection of a large number of DERs among the load on middle voltage/low voltage (MV/LV) feeders may result in a severe voltage regulation problem. These challenges motivate the application of wireless sensor and actuator networks (WSANs) into smart grid to coordinate DERs with the traditional voltage regulators, such as onload tap changer (OLTC), line regulators and switched shunt capacitors. Thus, to achieve proper voltage regulation it is absolutely necessary to improve the voltage measurement accuracy and assure a long voltage sensor network lifetime. In this paper, two sensor selection schemes are proposed to improve the voltage measurement performance. We first propose an opportunistic sensor selection scheme under equal power allocation and investigate the asymptotic behaviors. Then we address sensor selection scheme under optimal power allocation and derive a reminiscent of the “water-filling” solution for this scenario. Finally present are numerous studies on improving the power efficiency using sensor selection. The theoretical analysis and proofs are instrumental to the future sensor network design in smart grid.