An improved sensorless DTC-SVM for three-level inverter-fed permanent magnet synchronous motor drive
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A speed-sensorless control strategy is investigated in a wide speed range based on extended Kalman filter (EKF) and direct torque control with space vector modulation (DTC-SVM) for three-level cascaded H-bridge inverter-fed permanent magnet synchronous motor drives. The implementation of conventional SVM technique to the multilevel inverters is considerably complicated and leads to high computational burden. A three-level SVM technique simplified on the basis of two-level voltage vector diagram is proposed to reduce this computational complexity, and in addition, to satisfy some requirements for the safe operation of the inverter such as smooth commutation and minimum number of switching. The estimations of rotor position and speed are achieved using an EKF without high-frequency signal injection, especially at very low and zero speeds. The load torque is also estimated simultaneously to account for the mechanical frictions at steady state to improve the estimation performance. Furthermore, the flux trajectory control based on maximum torque per ampere algorithm is implemented to ensure maximal efficiency for constant torque region. The feasibility and effectiveness of the proposed drive system is tested under different operating conditions and verified by the simulation results.
KeywordsSensorless control Extended Kalman filter Load torque estimation Three-level H-bridge inverter Simplified three-level SVM
First author is supported by TUBITAK with 2214-A Doctorate Research Scholarship Programme. The authors would like to thank TUBITAK.
- 5.Swierczynski D, Kazmierkowski MP (2002) Direct torque control of permanent magnet synchronous motor (PMSM) using space vector modulation (DTC-SVM) simulation and experimental results. In: Proceedings of 28th annual IEEE industrial electronics, pp 751–755Google Scholar
- 16.Patil UV, Suryawanshi HM, Renge MM (2012) Multicarrier SVPWM controlled diode clamped multilevel inverter based DTC induction motor drive using DSP. In: Proceedings of IEEE power electronics, drives and energy systems, pp 1–5Google Scholar
- 17.Wang Y, Li H, Shi X (2006) Direct torque control with space vector modulation for induction motors fed by cascaded multilevel inverters. In: Proceedings of 32nd annual IEEE industrial electronics, pp 1575–1579Google Scholar
- 18.Gholinezhad J, Noroozian R (2012) Application of cascaded H-bridge multilevel inverter in DTC-SVM based induction motor drive. In: Proceedings of IEEE power electronics and drive system technology, pp 127–132Google Scholar
- 32.Muzikova V, Glasberger T, Smidl V, Peroutka Z (2014) Comparison of full-model and reduced-model EKF based position and speed estimators for sensorless DTC of permanent magnet synchronous machines. In: Proceedings of IEEE international conference on applied electronics, pp 1–4Google Scholar