Pulswidth modulation (PWM) methods were developed to grant the voltage source inverter (VSI) output signal better quality measures. The PWM method that VSI relies on must consider the utilization of the direct current (DC) source, especially when the drive system works in the overmodulation region. In this paper, different zero-sequence harmonic injection PWM methods are proposed. Two essential objectives are optimized by minimizing total harmonic distortion and maximizing the DC bus utilization. All schemes' results are compared with each other and with some of the commonly used PWM schemes. This paper concludes the usage of third, ninth, and fifteenth harmonic injections and any combination of them to reach a new PWM method that overtakes the disadvantages of other methods. Meanwhile, it provides a handy tool to operate VSI optimally. Ultimately, this work concludes to what extent is the zero-sequence injection is helpful. The work is evaluated experimentally, and the practical results match the simulation outcomes.