Three-phase

About: Three-phase is a research topic. Over the lifetime, 16801 publications have been published within this topic receiving 159477 citations.

Optimal current programming in three-phase high-power-factor rectifier based on two boost converters

Abstract: Current programming in a three-phase high-power-factor rectifier based on two boost converters is discussed in this paper. It is shown that the converter currents can be expressed in terms of two mutually related auxiliary functions. The auxiliary functions are related to the input current spectrum. Optimal auxiliary functions that eliminate harmonics of the input currents are derived. A method to generate reference signals for the optimal current programming is proposed. Experimental results confirming the proposed concepts are presented.

Overvoltage phenomena associated with virtual current chopping in three phase circuits

Abstract: Switching of three phase load currents with low power factors, such as encountered in arc furnace installations can result in a series of reignitions and clearings. Depending on the switch performance and system parameters the switching transients may involve one, two, or three phases. The effect of virtual current chopping which can lead to line to line overvoltages is described. The phenomena are explained for simplified conditions, more complex situations are handled by digital computer studies.

Modeling and Analysis of HVDC Converter by Three-Phase Dynamic Phasor

Abstract: A three-phase dynamic phasor (TPDP) model of high-voltage direct current (HVDC) systems, especially the converter, is proposed. The proposed model can rapidly solve the dynamic characteristics of the converter for symmetrical and asymmetrical operating conditions: 1) the symmetrical faults occur at the ac side or the dc side and 2) the asymmetrical faults occur at the ac side of the converter. Switch functions are used to indicate the commutation process of the converter. By using the sequence component method, it is observed that the vd should contain the 0th and 2nd components and ia,ib,ic should contain the 1st and 3rd components. The TPDP model of the HVDC converter is proposed based on these observations. The interface and the details to establish the proposed model are presented and a method to represent the commutation failure in the TPDP model is also proposed. Simulation results show that the proposed model is effective and acceptable.

Bidirectional Three-Phase DC–AC Converter With Embedded DC–DC Converter and Carrier-Based PWM Strategy for Wide Voltage Range Applications

Abstract: A bidirectional three-phase dc–ac converter with embedded dc–dc converter for bidirectional storage interface is proposed in this paper. With the help of the embedded dc–dc converter, the voltage of the storage battery can vary in a wide range. To minimize the power rating and power losses of the embedded dc–dc converter, a simple carrier-based pulsewidth modulation (PWM) strategy with zero-sequence injection is proposed. By adopting the proposed PWM strategy, only a small ratio of total power needs to be processed by the embedded dc–dc converter, while most of the power is only processed by the three-phase dc–ac stage within a single conversion stage. As a result, quasi single-stage power conversion is achieved to improve the conversion efficiency of the overall dc–ac power system. Principles, characteristics, and implementations of the proposed three-phase dc–ac converter and its PWM strategy are analyzed in detail. The feasibility and effectiveness of the proposed solutions are verified with experimental results.

Design of a Three-Phase Series Resonant Converter for Offshore DC Grids

Abstract: Offshore wind farms for the generation of electrical power is an ongoing discussion for several years. A major challenge today is to reduce the cost for the electrification of these large scale wind farms. A possible solution is to use a DC collector grid instead of conventional AC systems. However, to realize this, high-power DC/DC converters are needed to transform the voltages within the grid. The Series Resonant Converter, which will be discussed in this paper offers a possible solution that is efficient and cost effective. First, the fundamentals on three-phase SRC systems are discussed, before the soft-switching characteristics of high-power semiconductors are discussed and measurement results are presented. Next, a modified topology of the SRC is presented allowing an asymmetric bi-directional power flow which is essential for the usage in offshore wind farms. Finally, the total efficiency of converter will be determined tor different frequencies.