Experimental Comparisons and Evaluations of Different Types of DC-link Capacitors for VSI-Based Electric Compressors in Battery Electric Vehicle Systems
Electric compressor systems for air conditioning operations are an essential part in battery electric vehicle systems, which are not applicable to conventional belt-driven compressors due to no combustion engines. Three-phase voltage source inverters (VSI) and interior permanent magnet (IPM) motors are generally used for electric compressor systems in battery electric vehicles. Direct current (DC)-link capacitors are a critical component in the power converter systems, which affect the cost, size, performances and scale. Metallized polypropylene film capacitors are considered more reliable than conventional electrolytic capacitors for high temperature environments such as electric vehicle applications. This paper presents comprehensive comparisons and evaluations of electric compressors with two types of DC-link capacitors. Based on a 5 kW IPM motor drives and a VSI with a nominal DC voltage of 360 V for electric compressors, performances with electrolytic and film capacitors have been evaluated by experimental tests.