Premium
An Induction‐Motor Control Method for Minimization of Capacitor‐Voltage Fluctuations in a Modular Multilevel DSCC Inverter: Its Applications to a Quadratic‐Torque Load
Author(s) -
OKAZAKI YUHEI,
MATSUI HITOSHI,
MUHORO M. MOSES,
HAGIWARA MAKOTO,
AKAGI HIROFUMI
Publication year - 2017
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.23001
Subject(s) - control theory (sociology) , induction motor , torque , inverter , voltage , capacitor , direct torque control , modular design , cascade , stator , engineering , rotor (electric) , computer science , physics , electrical engineering , control (management) , artificial intelligence , chemical engineering , thermodynamics , operating system
Summary This paper aims at minimizing capacitor‐voltage fluctuations inherent in a modular multilevel cascade inverter based on double‐star chopper cell (DSCC) or a modular multilevel DSCC inverter. The inverter can drive an induction motor loaded with a quadratic‐torque load. Both theoretical analysis and numerical calculation reveal that the voltage fluctuations can be minimized when the ratio of a magnetizing‐current component with respect to a torque‐current component in the motor current is set to unity, regardless of the motor mechanical speed. A three‐phase DSCC inverter is designed and constructed to drive a 380‐V, 15‐kW, 50‐Hz, four‐pole, induction motor loaded with a quadratic torque that is proportional to a square of the motor mechanical speed. Experimental results confirm the validity of the theoretical and numerical calculations.