Three-phase

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

Simulation and comparison of spwm and svpwm control for three phase inverter

Abstract: A voltage source inverter is commonly used to supply a three-phase induction motor with variable frequency and variable voltage for variable speed applications. A suitable pulse width modulation (PWM) technique is employed to obtain the required output voltage in the line side of the inverter. The different methods for PWM generation can be broadly classified into Triangle comparison based PWM (TCPWM) and Space Vector based PWM (SVPWM). In TCPWM methods such as sine-triangle PWM, three phase reference modulating signals are compared against a common triangular carrier to generate the PWM signals for the three phases. In SVPWM methods, a revolving reference voltage vector is provided as voltage reference instead of three phase modulating waves. The magnitude and frequency of the fundamental component in the line side are controlled by the magnitude and frequency, respectively, of the reference vector. The highest possible peak phase fundamental is very less in sine triangle PWM when compared with space vector PWM. Space Vector Modulation (SVM) Technique has become the important PWM technique for three phase Voltage Source Inverters for the control of AC Induction, Brushless DC, Switched Reluctance and Permanent Magnet Synchronous Motors. The study of space vector modulation technique reveals that space vector modulation technique utilizes DC bus voltage more efficiently and generates less harmonic distortion when compared with Sinusoidal PWM (SPWM) technique. In this paper first a model for Space vector PWM is made and simulated using MATLAB/SIMULINK software and its performance is compared with Sinusoidal PWM. The simulation study reveals that Space vector PWM utilizes dc bus voltage more effectively and generates less THD when compared with sine PWM.

Circulating current suppressing controller in modular multilevel converter

Abstract: A circulating current suppressing controller (CCSC) is presented to eliminate the inner balancing currents in modular multilevel converter (MMC) Based on the double-fundamental-frequency, negative-sequence rotational frame, the three phase alternative circulating currents are decomposed to two DC components, and are limited to a low level by a pair of proportional integral controllers This control strategy does not affect the MMC outer dynamics in the ac side Simulation results based on PSCAD/EMTDC demonstrated the circulating current suppressing effect of the proposed CCSC and proved that the distortion of the arm current is mitigated significantly

An algorithm and implementation system for measuring impedance in the D-Q domain

Abstract: As power electronics infiltrates the electric power distribution and conversion systems, stability issues become increasingly significant. The risk of instability due to the use of constant power loads stems from the implementation of controlled output power conversion systems. In three phase converters, these issues are difficult to measure. Although there have been developments in the determination of system stability at interfaces due to stability, a framework to perform measurements necessary for such a determination has not been fully developed. This paper presents a method to measure three phase impedances in the D-Q rotating reference frame for three phase AC systems and demonstrates the successful implementation and operation of such a system. Results are shown measuring a three phase passive load with a 2 kW source.

Three-Phase AC/DC PWM Converter with Sinusoidal AC Currents and Minimum Filter Requirements

Abstract: A pulsewidth modulation (PWM) control technique suitable for fully controlled three-phase ac/dc converters is analyzed, which gives sinusoidal input currents and ideally smoothed dc voltage. The technique allows four-quadrant operation and full-range control of the input power factor. An extension to a simplified converter scheme, capable of one-quadrant operation, is also considered. Operation of the converter is analyzed under both ideal and actual conditions. Control implementation and design criteria are discussed and experimental results are reported.

Analysis and design of a new active power filter to cancel neutral current harmonics in three phase four wire electric distribution systems

Abstract: An active power filter for cancelling harmonic currents in the neutral of a three-phase four-wire system is proposed. This approach employs a star/delta transformer along with a two-switch PWM (pulse-width-modulated) controlled active filter. The closed-loop control of the active power filter guarantees cancellation of neutral current harmonics under varying load conditions. The proposed system greatly improves the overall system performance and virtually eliminates transformer overheating due to harmonics. Experimental results from a prototype active power filter confirm the suitability of the proposed approach. >