Three-phase

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

Method and system for ride-through of an adjustable speed drive for voltage sags and short-term power interruption

Abstract: In one embodiment of the present invention, a system for ride-through of an adjustable speed drive for voltage sags is provided. The system comprises an adjustable speed drive including a three phase electric utility, a diode rectifier, a dc-link, an inverter, and a motor. Coupled to the adjustable speed drive is a ride-through circuit which includes a controller having a first input and a second input, the first input operable to receive the voltage from each phase of the three phase electric utility and determine the magnitude and phase of the voltage sag, and the second input operable to receive the dc-link voltage to ensure that the rated dc-link voltage is not exceeded. Also included is an IGBT coupled to an output of the controller and operable to switch on and off rapidly based on the amount of voltage sag. An inductor associated with the IGBT and operable to store energy when the IGBT is switched on and to transfer energy to the dc-link when the IGBT is off is also included. This maintains the dc-link voltage to provide ride-through operation of the adjustable speed drive.

Three-Phase Power Converter-Based Real-Time Synchronous Generator Emulation

Abstract: This paper develops a synchronous generator emulator by using a three-phase voltage source converter for transmission level power system testing. Different interface algorithms are compared, and the voltage type ideal transformer model is selected considering accuracy and stability. At the same time, closed-loop voltage control with current feed-forward is proposed to decrease the emulation error. The emulation is then verified through two different ways. First, the output waveforms of the emulator in experiments are compared with the simulation under the same condition. Second, a transfer function perturbation-based error model is obtained and redefined as the relative error for the amplitude and phase between the emulated and the target system over the frequency range of interest. The major cause of the error is investigated through a quantitative analysis of the error with varying parameters.

Arbitrary Power Sharing Among Three-Phase Winding Sets of Multiphase Machines

Abstract: The paper develops a technique for arbitrary power sharing among three-phase winding sets of a multiphase generator. Multiple d − q modeling is commonly used when independent control of the winding sets is required. This paper utilizes instead the vector space decomposition modeling as the starting point and combines it with a multiple d − q approach to preserve the advantages of the vector space decomposition, while still enabling independent control over each winding set. The power sharing is achieved by imposing appropriate x − y currents at the fundamental frequency so that the flux and average torque are not affected. The theory is developed initially for the nine-phase machine. A general expression for arbitrary current sharing is derived further for any multiphase machine with multiple three-phase windings. The obtained equations are valid for any possible machine topology (asymmetrical/symmetrical, with single or multiple neutral points). The theory is validated experimentally using an asymmetrical nine-phase induction generator with indirect rotor field oriented control.

An Approach to Fault-Tolerant Three-Phase Matrix Converter Drives

Abstract: Despite numerous research efforts in matrix converter-based drives, a study of fault-tolerant topology and control strategy for a matrix converter drive has not been presented in the literature. This paper proposes a matrix converter structure and a modulation technique for the remedial operation in case of opened switch faults and single-phase open circuits. The fault compensation is achieved by reconfiguring the matrix converter topology with the help of a connecting device. Based on the redefined converter structure, a fault-tolerant modulation algorithm is developed to reshape output currents of two unfaulty phases for obtaining continuous operation. The proposed method allows improved system reliability and fault-tolerant capability with no backup leg and no parallel redundancy. Simulation and experimental results are shown to demonstrate the feasibility of the proposed fault-tolerant approach to the matrix converter drives.

Power-Loss Analysis and Efficiency Maximization of a Silicon-Carbide MOSFET-Based Three-Phase 10-kW Bidirectional EV Charger Using Variable-DC-Bus Control

Abstract: It is expected that wide-bandgap devices like silicon-carbide MOSFETs and gallium-nitride HEMTs could replace Si devices in power electronics converters to reach higher system efficiency. This paper adopts the conventional half-bridge LLC topology to realize a 10-kW all-SiC bidirectional charger used in electric vehicles. Though it is a well-known topology for the unidirectional charger, it has not been comprehensively explored for the bidirectional energy flow yet. A double-pulse-test (DPT) platform is utilized to provide accurate power losses. A state-space model is built to obtain accurate switching current waveforms, which is eventually combined with the DPT results to accurately predict the system efficiency. Based on this model, to further enhance the system efficiency, the dc-bus voltage is varied with LLC dc/dc converter running at the resonant frequency through the whole power range. Experimental results validated that the proposed approach could realize the bidirectional power flow. By varying the dc-bus voltage, the V2G and G2V modes reach $\sim 96$ % wall-to-battery efficiency.