Title :
Novel control strategy for three-stage 18-level hybrid multilevel inverter
Author :
Abdul Kadir, Mohamad N. ; Mekhlif, Saad ; Ping, Hew Wei
Author_Institution :
Dept. of Electr. Eng., Malaya Univ., Kuala Lumpur
Abstract :
This paper presents a multilevel multistage inverter design and its corresponding control strategy. The hybrid inverter has a high voltage stage composed of the six-switch conventional three phase inverter with its output connected in series with the outputs of three-level H-bridge medium and low voltage stages. The voltage ratio has been selected to enable both one state - approximation and PWM control modes effectively. The suggested control strategy has been developed to ensure minimum switching losses focusing on holding the higher voltage stage state as long as it is feasible. The reference voltage vector has been approximated to the nearest of the 919 vectors provided by the 18-level inverter. A special definition of state zone has been introduced for the low voltage stage to enable the achievement of the reference vector with minimum error. The proposed control strategy has been tested and its short computational time and low memory requirement has been proven.
Keywords :
PWM invertors; control system synthesis; PWM control modes; reference voltage vector; six-switch three phase inverter; three-stage 18-level hybrid multilevel inverter; Circuit topology; Control systems; Costs; Low voltage; Pulse width modulation; Pulse width modulation converters; Pulse width modulation inverters; Space vector pulse width modulation; Switching frequency; Voltage control; Converters; DSP control; multilevel inverters; pulse width modulation;
Conference_Titel :
Systems, Signals and Devices, 2009. SSD '09. 6th International Multi-Conference on
Conference_Location :
Djerba
Print_ISBN :
978-1-4244-4345-1
Electronic_ISBN :
978-1-4244-4346-8
DOI :
10.1109/SSD.2009.4956745