A Fast Carrier-Based Pulse-Width Modulation Scheme Equivalent to Space Vector Modulation for Current Source Inverters

Current source inverters (CSIs) have exhibited significant potential in variable-speed motor drive applications, attributed to their superior dynamic response and robust anti-interference capabilities. Space vector pulse-width modulation (SVPWM) is renowned for its exceptional performance and has been extensively adopted in CSIs. Nevertheless, the implementation of SVPWM is substantially more complex than that of carrier-based pulse-width modulation (CBPWM). This paper proposes a CBPWM strategy for CSIs that achieves full equivalence to SVPWM while delivering enhanced implementation simplicity, computational efficiency, and reduced processor resource demand. In that approach, three-phase pseudo-modulated signals are compared with a triangular carrier waveform to generate three two-level PWM signals. Subsequently, pairwise subtraction of these two-level signals yields three three-level PWM signals. In addition, the injection of zero-sequence current enables the same DC current utilization rate as that achieved by SVPWM. The devices within each bridge arm are then controlled according to the three-level PWM signals, enabling the output of desired current pulses for the CSI. The proposed CBPWM scheme determines all switching states, duty cycles, and switching sequences through straightforward carrier comparisons and basic arithmetic operations, thereby eliminating the need for computationally intensive sinusoidal calculations while achieving equivalence to the SVPWM method. Simulation and experimental results demonstrate that the output performance of CBPWM is equivalent to that of SVPWM, while also validating the proposed method’s structural simplicity and computational efficiency for CSIs.