Three-phase

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

A Real-Time Multiple Open-Circuit Fault Diagnosis Method in Voltage-Source-Inverter Fed Vector Controlled Drives

Abstract: This paper proposed a fast, real-time and fair robustness scheme for single switch and double switches open-circuit fault diagnosis in pulse-width-modulated voltage source inverter (VSI) for vector-controlled induction motor drives based on three phase output currents, which is also easy to insert into the controlled algorithm as a subroutine without major modification. The concept of allelic points is proposed and corresponding functions are defined to describe the symmetry of the VSI physical topology under healthy and faulty conditions. The residuals between any two phase functions are applied as criterion for allelic points. Under healthy condition, three legs are symmetrical and the residuals are all closed to zero, when open-circuit fault occurs, the residuals will be larger than a predefined threshold, so it is used to detect fault occurrence. When fault occurs, the near-zero current samples per fundamental period will get large, its proportions in a period will be different when different fault classes occur. The fault can be located combined the functions and residuals based on the analysis of VSI topology. The simulations and experiments are carried out and the results show the effectiveness and the merits of the proposed method.

Active Damping for Three-Phase PWM Rectifiers With High-Order Line-Side Filters

Abstract: Active rectifiers interfacing the grid have gained much attention in recent years due to their current control capability that enables the application to exchange a certain range of power at the benefit of low harmonic distortion compared to line commutated converters. Moreover, the amount of active and reactive powers can be arbitrarily chosen within certain limits. These limits as well as the degree of harmonic attenuation is determined by the line-side filter. This paper basically focuses on the current control of active rectifiers incorporating a line-side filter of first- up to third-order degree. Thus, it treats both the current-source converter (CSC) as well as the voltage-source converter (VSC). The basic models of the plant are derived for each case, and important dualities are pointed out. As a conclusion, a recipe for the controller design of particularly CSCs with LC filters and VSCs with LCL filters is proposed.

Railway Static Power Conditioners for High-speed Train Traction Power Supply Systems Using Three-phase V/V Transformers

Abstract: In order to eliminate the negative-sequence and harmonic currents in the high-speed train traction systems with three-phase V/V transformers, a compensation strategy based on the railway static power conditioners (RPC) is proposed in this paper. An RPC contains two converters that are connected back to back by sharing the same dc link. In this paper, the structure and principle to compensate negative-sequence currents for the RPC with a three-phase V/V transformer are explained, and a strategy to provide the compensation references for negative-sequence and harmonic currents is proposed. Also, a method to separate active current, reactive current, and harmonic current references from the total negative-sequence and harmonic current references is given. Moreover, a controller is proposed to maintain the dc-link voltage and to compensate the negative-sequence and harmonic currents. Simulation and experimental results are provided to demonstrate that the proposed strategy is very effective.

Six Phase Synchronous Machine with AC and DC Stator Connections, Part I: Equivalent Circuit Representation and Steady-State Analysis

Abstract: This paper describes a detailed circuit representation of a six phase synchronous machine wherein mutual leakage couplings between the two sets of three phase stator windings are included. The main modes of power transfer of a six phase machine with sinusoidal inputs are examined. A harmonic phasor method of steady-state analysis to obtain the current, voltage and torque waveforms of a six phase machine with mixed AC-DC stator connections is described. It is shown that the output waveforms for various operating conditions from a digital computer program using the harmonic phasor method agree remarkably well with those obtained from an established detailed analog simulation.

Three-Phase Power Flow Based on Four-Conductor Current Injection Method for Unbalanced Distribution Networks

Abstract: This work presents a new formulation for the power flow problem, with explicit representation of the neutral conductor and grounding. This methodology has been named the four-conductor current injection method (FCIM). The Newton-Raphson method is applied to solve the set of nonlinear current injection equations that are derived using phase coordinates, and the complex variables are written in rectangular form. The proposed algorithm can be used to analyze both balanced and unbalanced systems, meshed or radial, with controls and distributed generation, and is shown to be very efficient and robust for large scale systems.