On Influence of Non Deterministic Modulation Schemes on a Drive Train System With a PMSM Within an Electric Vehicle

A drive train system (DTS) powered by an ideal voltage source and driving a permanent-magnet synchronous motor (PMSM) is discussed in this paper. A two-level three-phase voltage source inverter is used as a means of power conditioning. This converter is not equipped with any harmonic filters on neither the ac nor the dc side. The mechanical part of the DTS is modeled as a double oscillator according to a drive train in an electric vehicle (EV). Various inverter modulation schemes are applied, namely, a single-phase hysteresis scheme, two-space vector-based hysteresis control schemes, for one, a stator aligned hysteresis and for another, a rotor aligned hysteresis, a modulation scheme based on pulsewidth modulation (PWM), such as sinusoidal modulation (including zero-sequence components) and space-vector pulsewidth modulation (SVPWM). The hysteresis-based pulsing methods are nondeterministic and build a current controller in their structure by nature. The other pulsing methods are deterministic due to their underlying PWM and require a separate control unit. The influence of these modulation schemes on the performance of the DTS is determined by assessing the level of inverter generated harmonics flowing to the PMSM and to the tires [downforce, (mechanical part)] as well as the resulting switching frequency (electrical part). The simulated results presented in the paper indicate that the pulsing frequency can be reduced by means of the hysteresis controller. In addition, the dispersion of the harmonic energy of the inverter generated spectrum partly compensate the absence of filters.