• THAKUR SUMEET SINGH

• Maximum power per VA control of vector controlled interior permanent magnet motor

Maximum Torque Per Ampere is the commonly used technique for operating interior permanent magnet (IPM) motor while little work is reported towards maximum power-factor operation i.e., Maximum Power Per Volt-Ampere (MPVA). The MPVA operation allows maximum-utilization of the drive-system. Thecontrol technique is developed using detailed mathematical model of IPM motor in MPVA, and the solution to the quartic equations involved is derived and analyzed. The solution is utilized to develop LUT for implementation of MPVA control. The comparison of MTPA and MPVA technique is established to demonstrate itsmerits and demerits. The proposed algorithm is supported by simulation and experimental results on a 5.5 KW vector controlled IPM drive.

• Simplified current minimization control of vector controlled Interior Permanent Magnet motor

This paper presents a simplified current minimizing technique for Interior Permanent Magnet (IPM) motor. This is primarily achieved by utilizing normalized 2D-Look Up Table (LUT) that is parameter independent except for saliency ratio. In addition, torque-flux reference frame is considered for implementation to reduce the complexity generally present in conventional methods utilizing ids - iqs current reference frame. The proposed algorithm also incorporates both the aspects that lead to field weakening operation, i.e., increase in speed and reduction of dc link voltage. A novel compensation method for incorporating saturation effect is also addressed. The current minimizing technique is analyzed in detail, supported by experimental results.

• Voltage minimization control of vector controlled interior permanent magnet motor

Maximum Torque Per Voltage trajectory has been utilized only during field weakening operation of Interior Permanent Magnet (IPM) motor. In this paper, the voltage minimization control from zero-speed is proposed. Voltage minimization results in maximum torque per voltage control of IPM motor. The control implementation is also simple in comparison to current minimization, as the operation is always along the current-limit locus irrespective of operation in field-weakening. Voltage minimization technique minimizes the core losses whereas current minimization would minimize the copper losses. The mathematical model of IPM motor following voltage minimization is derived and the solution to the 4th order quartic equations is obtained using Ferrari’s method. The solution obtained is utilized to develop a look-up table for vector control of IPM motor. A comparative analysis of voltage minimization and current minimization is established which is supported by simulation results and demonstrated by detailed experimental results.