This paper proposes the new clamping angle control (CAC) pulse width modulation (PWM) method to restore its maximum linear modulation range of voltage source inverters (VSIs) reduced by the duty ratio limitation in hardware implementation, which makes the VSIs to operate nonlinearly in the high modulation range. The deadtime and the bootstrap gate driver circuit mainly cause this duty ratio limitation in practice. In particular, the bootstrap gate driver circuit is used in many industrial applications by avoiding the additional power supply to apply the gate-source voltage of power switches, and therefore making the VSIs to be small size with the low cost. First, the proposed CACPWM method is theoretically analyzed. Then, it is applied in the high modulation range to overcome the limitation of the duty ratio due to the use of the bootstrap gate driver circuit. Thereafter, its practical effectiveness is verified by both simulation and experimental tests. Also, the resulting harmonic distortions are compared with those by the conventional PWM methods.
Manuscript received June 12, 2017; revised December 27, 2017; accepted February 4, 2018. Date of publication February 15, 2018; date of current version September 28, 2018. This work was supported in part by the National Research Foundation of Korea funded by the Korea government under Grant 2016R1E1A1A-02920095 and in part by the Power Generation and Electricity Delivery Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning funded by the Ministry of Trade, Industry and Energy, Republic of Korea, under Grant 20171220100330. Recommended for publication by Associate Editor Dorin O Neacsu. (Corresponding author: Jung-Wook Park.) J.-G. Kim and J.-W. Park are with the School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, South Korea (e-mail: jaegoo@ yonsei.ac.kr; jungpark@yonsei.ac.kr).
