## 6 Discussion
However, most real-time controllers are sufficient to control both inverters simultaneously, allowing the proposed method to be implemented effectively. Studies [10; 11] use feedforward compensation to equalize the rectifier side current and the inverter side current. In research [12], the harmonics of the boost converter are cancelled out by the harmonics of the inverter by applying a phase difference between the carriers of these converters. The results show a 70% reduction in the dc-link capacitor current. In this paper, no converter (boost converter or rectifier) is required on the source side, and the dual-source inverters are connected directly to the battery bank. In other words, the harmonics of one VSI are cancelled by the harmonics of the other VSI. The study in [14] found similar results to this article. Inserting \(\pi/2\) rad phase difference between the carrier waves reduces the second carrier harmonic of the dc-link capacitor current. The load is a six-phase motor controlled by dual VSIs. In addition, there is a rectifier at the input of the VSIs. The method proposed in this article does not require a six-phase motor; it is sufficient to have two different three-phase motors working together. Some studies [15; 16; 17] introduce the carrier phase shifting method to reduce the high-frequency current noise and vibration noise of the two-segment three-phase motor. The shifting angle is \(\pi/2\) rad, as concluded in this article. The two-segmented three-phase motor means that it is a motor with six phases. However in this article, two three-phase PMSMs are driven and used in the experiments. The advantage of this article is that PMSMs can work in different operating conditions. Considering the result of research [15; 16; 17], there is a phase difference between the carrier waves, which causes a decrease in the vibration noise for the dual-branch motor. In other words, when there is a \(\pi/2\) phase difference between the carrier waves of VSIs driving two motors, the vibration and noise of one motor is decreased by the other motor if two motors are connected to the same system. In research [18], optimal phase shift is studied for different PWM techniques such as SVPWM and discontinuous PWMs. The phase shift of \(\pi/2\) rad found a similar result in this article for the SVPWM technique. The maximum reduction in the dc-link capacitor current is 84% according to the simulation results of [18]. However, in this article, the maximum reduction in the dc-link capacitor current is about 75%. Since the power factor of the VSIs in [18] is chosen as unity, the current reduction is lower than in this article, where the power factor is chosen as 0.96. In addition, load is the six-phase PMSM in [18]. According to [19], the insertion of \(\pi\) rad difference between the sawtooth carriers leads to a greater reduction in the dc-link capacitor current compared to the \(\pi/2\) rad difference between the triangular carriers, as shown in the PLECS simulation. In this article, only the triangular carrier waves with the SVPWM technique are researched. In the future, research could also be conducted on this topic. The advantage of this article is that there is an experimental setup for driving two PMSMs.