Three-phase

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

A Three-Phase Optimal Power-Flow Algorithm to Mitigate Voltage Unbalance

Abstract: This paper describes a new methodology for three-phase electrical system optimization, in which the phase unbalances are to be taken into account. A formulation for the three-phase optimal power-flow solution was developed using the primal-dual interior point method and the three-phase current injection method in rectangular coordinates. The Hessian matrix has a 6 × 6 blocked structure, where most of the elements are constant or equal to zero during the solution process. This characteristic brings computational efficiency when applied to three-phase systems.

A WBG based three phase 12.5 kW 500 kHz CLLC resonant converter with integrated PCB winding transformer

Abstract: The three phase resonant converter gains its popularity in high power areas like off-board charger due to its ability to reduce the current stress on devices and achieve higher efficiency. However, very few takes this advantage for the transformer integration to reduce the size of the magnetic components. In addition, by using wide-band-gap devices, the switching frequency of power electronics converters can be pushed to a much higher level, making it possible to implement Printed Circuit Board (PCB) transformer. In this paper, a novel 6-layer only PCB winding transformer is proposed for a three phase CLLC resonant converter. Not only all the resonant inductors are integrated into the transformer, but also the three phase transformers are integrated together so that the size of the magnetic component is significantly reduced. A 12.5 kW 500 kHz hardware prototype with over 97.3% efficiency and 155 W/in3 power density is built to verify the feasibility of the proposed structure.

Integrated Field and Armature Current Control for Dual Three-Phase Variable Flux Reluctance Machine Drives

Abstract: An integrated field and armature current control strategy is proposed for dual three-phase variable flux reluctance machines (VFRMs). The proposed method utilizes a sinusoidal current biased by dc offset rather than separated field and armature currents in an external field current control. In order to generate the dc and ac components together, a dual three-phase inverter is adopted, in which one side of each stator winding is connected to a neutral point. The dq -axis currents are controlled by the dual three-phase inverter, whereas zero sequence current is generated as a field current by the zero vector redistribution between two inverters. Since the integrated current control allows an integrated winding, which reduces the winding resistance to half, the copper loss can be also reduced to half. To apply the vector control scheme, the voltage and torque equations are derived for dual three-phase VFRMs in a synchronous dq -axis frame. These equations are also utilized for the dynamic simulation with the aid of MATLAB/Simulink. The experimental results validate that the proposed strategy can effectively increase the efficiency and extend the operating speed range.

Evaluation of 1200 V-Si-IGBTs and 1300 V-SiC-JFETs for application in three-phase very sparse matrix AC-AC converter systems

Abstract: In this paper based on experimental investigations of the power semiconductor switching behavior and on analytical calculations the conduction and switching losses of it three-phase very sparse AC-AC matrix converter (VSMC) supplying a permanent magnet synchronous motor are discussed in detail. There, 1200 V-Si-IGBTs/1200 V-Si-ultra-fast-recovery diodes and 1300 V-SiC-JFET/Si-MOSFET cascodes are employed for realizing the converter power circuit. The worst case operating conditions are identified and the efficiencies resulting in dependency of the switching frequency and load current amplitude are shown in graphical form. Furthermore, the operating range of the VSMC with respect to the maximum admissible junction temperature of the power semiconductors is determined. Finally, topics to be treated in the continuation of the research are discussed briefly.

An Improved Three-Phase Five-Level Inverter Topology With Reduced Number of Switching Power Devices

Abstract: This paper presents an optimized topology of 3- $\phi$ , multilevel inverter (MLI) configuration for five or higher level operation with reduced switch count. The proposed solution consists of two basic units (BUs) of multilevel converter and a T-structured 3-level inverter (3-LI). Both BUs are equally shared by the three phases maintaining symmetry among the phases. Moreover, for a higher level operation of the proposed MLI, the modifications required are at two BUs only and not at three legs of the inverter. It further helps in reducing the requirement of extra components for higher level operation compared to the conventional solutions. Furthermore, the topology also has the benefits of reduced switching and conduction loss. An algorithm is also devised to generate the switching pulses for the BUs and the 3-LI, using a carrier-based space vector modulation technique. Presented topology is compared with other existing topologies to prove its advantage. All the details regarding the operating modes and pulse width modulation techniques employed for the proposed system are given and supported by the simulation and experimental results.