Integrated Inverter/Converter Circuit and Control Technique of Motor Drives With Dual-Mode Control for EV/HEV Applications

A new integrated circuit for motor drives with dual-mode control for EV/HEV applications is proposed. The proposed integrated circuit allows the permanent magnet synchronous motor to operate in motormode or acts as boost inductors of the boost converter, and thereby boosting the output torque coupled to the same transmission system or dc-link voltage of the inverter connected to the output of the integrated circuit. In motor mode, the proposed integrated circuit acts as an inverter and it becomes a boost-type boost converter, while using the motor windings as the boost inductors to boost the converter output voltage. Moreover, a new control technique for the proposed integrated circuit under boost converter mode is proposed to increase the efficiency. The proposed control technique is to use interleaved control to significantly reduce the current ripple and thereby reducing the losses and thermal stress under heavy-load condition. In contrast, single-phase control is used for not invoking additional switching and conduction losses under light-load condition. Experimental results derived from digital-controlled 3-kW inverter/converter using digital signal processing show the voltage boost ratio can go up to 600 W to 3 kW. And the efficiency is 93.83% under full-load condition while keeping the motor temperature at the atmosphere level. These results fully confirm the claimed merits for the proposed integrated circuit.