THE VECTOR CONTROL TECHNIQUES FOR LOW VOLTAGE IPM MACHINE IN

Due to the decreasing level of fuel and concern for clean environment, the automotive industry is being pushed for manufacturing more and more fuel-economic and environment friendly cars. As a result many mechanically driven auxiliaries are being replaced by electrical ones. The passengers’ comforts and safety are also increasing with time. All these are leading us to an elevated on board power demand. In order to cope with the higher demands, present dc bus voltage level of 12 V need to be increased to 42 V. Considering efficiency and size, the IPM(Interior type Permanent Magnet) machines are attracting attentions from research community for variety of automotive applications-from vehicle propulsion to integrated starter alternator (ISA). Although the design of IPM machine for extended speed operation itself poses many technical difficulties, the success of the complete drive system depends on the availability of a control algorithm that can extract the most efficient performance capability from the machine. Due to the practical constraint of some applications such as ISA, the IPM machines can have characteristic current less than its peak current rating. In this paper an investigation has been made to find out the most suitable control algorithm for a low voltage IPM machine of 42 V system that have characteristic current less than its peak rated curren