Wenping Cao

By Wenping Cao

Part of the book: Wind Turbines

By Wenping Cao, Ying Xie and Zheng Tan

Part of the book: Advances in Wind Power

By Yihua Hu, Chun Gan, Wenping Cao and Stephen Finney

Electric vehicles (EVs) and hybrid electric vehicles (HEVs) can reduce greenhouse gas emissions while switched reluctance motors (SRMs) are one promising motor technology for EVs. This chapter illustrates the fault diagnosis and fault tolerance operation of SRM-based EVs/HEVs, where high reliability is a vital factor involving human lives. Based on the traditional asymmetric half-bridge topology for SRM drives, the characteristics of switching devices upon open-circuit and short-circuit are analyzed, and the corresponding fault diagnosis methods are developed. In order to achieve fault tolerance operation, the central point of SRM stator winding is tapped to form a modular half-bridge configuration to provide fault diagnosis and fault tolerance functions. The fault diagnosis functions are set idle in normal conditions. Simulation results in Matlab/Simulink and experimental results on a 150-W four-phase 8/6 SRM are used to validate the fault identification, and on a 750-W, three-phase 12/8 SRM are used to validate the fault tolerance operation of the proposed strategy, which may have significant implications for EV/HEV applications.

Part of the book: New Applications of Electric Drives

By Yihua Hu and Wenping Cao

The utilization of solar energy by photovoltaics (PVs) is seen in increase across the world since the technologies are getting mature and the material costs are being driven down. However, their operating costs are still very high, owing to their vulnerability to harsh outdoor environments they are working. Currently, the reliability of PV systems is the bottle-neck issue and is becoming a heated research topic. This chapter presents the state-of-the-art technologies for photovoltaic fault diagnosis, based on an intensive literature review and theoretical analysis. The chapter evaluates the fault mechanisms of photovoltaics at the cell, module, string and array levels. Analytical models are developed to understand the PV’s terminal characteristics for diagnostic purposes. Offline and online fault diagnosis technologies are reviewed and compared based on the use of electrical sensors and thermal cameras. The aim of this chapter is to illustrate the PV faulty characteristics, to develop offline and online fault diagnosis, and to use the fault diagnosis information to achieve optimal operation (maximum power point tracking) under various PV faulty conditions, by using multi-disciplinary analytical, empirical and experimental methods.

Part of the book: Renewable Energy