Effects of leakage inductance on the input current of double-star diode rectifier with active inter-phase

An Active Inter-Phase Reactor (AIPR) is often employed to inject triangle current to improve the input current quality of double-star diode rectier. Due to the existing leakage inductance of transformer, the input current harmonics suppression ability of the injected triangle current would be weakened. In this paper, the current commutation process of the double-star diode rectier with AIPR is analyzed initially. Then, according to the relation between the input current and output current of the double-star transformer, the relation between the leakage inductance and the input line current of double-star diode rectier with AIPR is established. Such factors like the input current THD, the input current lag angle, and power factor of the double-star diode rectier with AIPR as well as their relations with the leakage inductance are also obtained. The theoretical analysis demonstrates that leakage inductance increases the input current THD and lag angle. It indicates that leakage inductance decreases the displacement factor and power factor. To ensure the input current THD is less than 5% and the power factor is more than 0.998, the leakage inductance factor, KLS, should be less than 0.22. Simulation results verify the theoretical analysis.