Zero-Sequence Current Suppression Strategy With Reduced Switching Frequency for Open-End Winding PMSM Drives With Common DC BUS

A Zero-Sequence Steerable CBPWM Strategy for Eliminating Zero-Sequence Current of Dual-Inverter Fed Open-End Winding Transformer Based PV Grid-Tied System With Common DC Bus

“…L i_0 is a relatively small value due to the lack of independent flux return paths in the three-phase three-limb inductor L i . Hence, if using the ZSC suppression method which only considering the elimination of low-frequency ZSV [25]- [27], the excessive highfrequency ZSC can be easily induced by the high-frequency ZSV disturbance. Therefore, in order to suppress the ZSC effectively, both the low-frequency and high-frequency ZSV need to be reduced to a promising value.…”

“…It can be found from (27) and (28) that, if the switching frequency is selected, the generated ZSV range is proportional to the zero vector's dwell time T 0 and the DC voltage v dc . Obviously, if T 0 is equal to zero, there is no adjustment margin for generating the desired ZSV and the ZSC will exist inevitably.…”

“…In [26], a proportional resonant (PR) regulator and zero vector redistribution (ZVR) SVPWM strategy based ZSC suppression method was proposed. In [27], a novel ZSC suppression method with a PR regulator and a reduced switching frequency modulation strategy was presented. All [25], [26] and [27] achieved good ZSC suppression effect in the open-end winding PMSG system with the corresponding method.…”

“…In [27], a novel ZSC suppression method with a PR regulator and a reduced switching frequency modulation strategy was presented. All [25], [26] and [27] achieved good ZSC suppression effect in the open-end winding PMSG system with the corresponding method. However, it should be noted that these methods mainly consider the suppression of low-frequency ZSC, the high-frequency ZSC is generally suppressed by the motor stator inductance.…”

“…For the OEWT-DI based PV inverters, the three-phase three-limb inductors are usually used as the filter inductors for the purpose of cost and size reduction. But this kind of inductor has the characteristic that the zero-sequence inductance is relatively small owing to the lack of independent flux return paths [31], so the adoption of these methods [25]- [27] will inevitably result in excessive high-frequency ZSC, which is unacceptable. In [28], a PR regulator and a switching signal phase shift based sinusoidal PWM strategy was proposed to suppress the ZSC, both the high-and low-frequency ZSC were effectively suppressed.…”