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Poly-phase systems have been used for many years in machines and recently in wind power generations. They usually are built by a dual three-phase system, shifted by 30 electrical degrees from each other and with no neutral connection. Typically, this system employs a twelve-pulse diode rectifier to converter ac to dc voltages. However, it may be improved if an active rectifier is used, because it can provide lower distortion in generator currents and regulated output voltage. Taking that into account, this paper proposes a six-phase active rectifier topology for a dual three-phase system. A stationary frame reference for six-phase system is applied to obtain the converter dynamic model in the αβ coordinates and thus a control strategy is proposed in this frame reference. The proposed topology, dynamic model and control strategy were verified by simulation for following specification: 12 kW, 220 V at input voltage and 800 V at the output voltage. The results were appropriated, providing a regulated output voltage, an input current with reduced harmonic distortion and thus high power factor.

Poly-phase systems have been used for many years in machines and recently in wind power generations. Typically, this system employs diode rectifiers, however, it may be improved employing active rectifier. Considering it, this paper proposes a six-phase active rectifier topology controlled in synchronous frame reference. Results were validated by simulation.

This paper proposes a method for calculation of the instantaneous active and reactive power in six-phase system, derived from the Akagi three-phase instantaneous power theory, the proposed method is physical analyzed and the results are validated by simulation.

This paper approaches the implementation of a control strategy with communication for three-phase four-wire VSI parallel connected, which is based on distributed control. The paper presents details of implementation of one control strategy that employs two loops, one voltage control and one parallelism control, all system is done on instantaneous values and the parallelism control shares only a voltage reference signal among the VISs. The strategy ensures power load shared among the inverters in steady-state and a fast dynamic response during connection or disconnection of VSI and load step. The control system was implemented in a TMS320F28069 DSP and verified in two 2 kVA VSI parallel-connected.

This paper describes a theoretical and experimental study on a digital communication system, which is employed in a control strategy for parallelism of three-phase voltage inverter (VSI). This control strategy only needs that all VSIs use a same voltage reference and thus it ensures the sharing of the load current and avoids current circulation among the inverters during transient and steady-state operation. Therefore, the communication among the inverter is implemented to transmit only the voltage reference. The paper proposes this communication system based on two bus, one that uses the own electrical grid and is called of Voltage Reference bus and another makes by CAN bus. The first puts the reference voltage of all inverters in synchronism and the second keeps the reference voltage in synchronism even during a fault of electrical grid. The proposed system was digitally implemented in a TMS320F2812 DSP and was verified through experimental results with a 10 kVA prototype, which has the parallel operation of two three-phase VSIs.