A system of frequency converter based on DeviceNet Fieldbus

2012 ◽  
Author(s):  
Feng Jin ◽  
Liang Dong ◽  
Wenwei Liu
Keyword(s):  
Frequency Converter

FREQUENCY CONVERTER WITH THE REDUCED THD OF THE OUTPUT VOLTAGE

2016 ◽  
Vol 2016 (5) ◽  
pp. 14-16 ◽  
Author(s):  
G.V. Pavlov ◽  
◽  
I.L. Vinnichenko ◽  
A.V. Obrubov ◽  
◽  
...  
Keyword(s):  
Output Voltage ◽  
Frequency Converter

Steady-state modelling method for matrix-reactance frequency converter with boost topology

2011 ◽  
Vol 60 (2) ◽  
pp. 137-148
Author(s):  
Igor Korotyeyev ◽  
Beata Zięba
Keyword(s):  
Fourier Series ◽  
Steady State ◽  
Differential Equations ◽  
Numerical Method ◽  
Frequency Converter ◽  
Double Fourier Series ◽  
Galerkin’S Method ◽  
Galerkin's Method ◽  
Modelling Method ◽  
Three Phase

Steady-state modelling method for matrix-reactance frequency converter with boost topologyThis paper presents a method intended for calculation of steady-state processes in AC/AC three-phase converters that are described by nonstationary periodical differential equations. The method is based on the extension of nonstationary differential equations and the use of Galerkin's method. The results of calculations are presented in the form of a double Fourier series. As an example, a three-phase matrix-reactance frequency converter (MRFC) with boost topology is considered and the results of computation are compared with a numerical method.

Measurement of the Air Pressure for a Rotary Vane Compressor

2003 ◽  
Author(s):  
Yuan Mao Huang ◽  
Sheng An Yang
Keyword(s):  
Frequency Converter ◽  
Air Pressure ◽  
Cover Plate ◽  
Rotary Compressor ◽  
Compression Phase ◽  
Pressure Transducers ◽  
Compressor Rotor ◽  
Two Phases ◽  
Rotary Vane Compressor ◽  
Type Pressure

This study introduces an experimental method that can measure air pressures in the vane segments when a sliding-vane rotary compressor performs suction and compression phases in stable or unstable rotational speeds. When the air pressures of these two phases can be measured, the intake effect of the compressor’s inlet and the seal effect of the vane segments can be evaluated, respectively. Because a frequency converter provides unstable rotational speeds when it controls rotational speeds of a motor with a compressor, an encoder mounted on the output shaft of the motor was applied to record the angular location of the compressor rotor. Two strain gauge type pressure transducers were inserted into the cover plate of the compressor to measure air pressures in the vane segments. Comparing the signals of the encoder with pressure transducers, the air pressures in completions of suction and compression phases could be determined in stable or unstable rotational speeds. The air pressures when the compressor performed suction and compression phases were 99.5 kPa and 153 kPa, respectively, in 1400 rpm. The air pressure when the compressor performed suction phase decreased with the rotational speed faster than 800 rpm. The size or shape of the inlet port of the compressor should be enlarged or modified to provide the suction air pressure without dropping too much. The designed air pressure when the compressor performed compression phase was 244 kPa in 140 rpm, the manufacture precision of the compressor should be increased to decrease leakage.

Research and Develop on Static Frequency Converter of Pumped Storage Power Plant

2012 ◽  
Vol 608-609 ◽  
pp. 1120-1126 ◽  
Author(s):  
De Shun Wang ◽  
Bo Yang ◽  
Lian Tao Ji
Keyword(s):  
Power Plant ◽  
Control Strategy ◽  
Large Scale ◽  
Frequency Converter ◽  
Position Estimation ◽  
Position Sensor ◽  
Storage Unit ◽  
Rotor Position ◽  
Start Up ◽  
Pumped Storage

A static frequency converter start-up control strategy for pumped-storage power unit is presented. And rotor position detecting without position sensor is realized according to voltage and magnetism equations of ideal synchronous motor mathematics model. The mechanism and implementation method of initial rotor position determination and rotor position estimation under low frequency without position sensor are expounded and validated by simulations. Based on the mentioned control strategy, first set of a static frequency converter start-up device in China for large-scale pumped-storage unit is developed, which is applied to start-up control test in the 90 MW generator/motor of Panjiakou Pumped-storage Power Plant. Test results show that rotor position detecting, pulse commutation, natural commutation, and unit synchronous procedure control of static start-up are all proved. The outcomes have been applied in running equipment, which proves the feasibility of mentioned method.

scholarly journals Insulation Life Span of Low-Voltage Electric Motors—A Survey

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1738
Author(s):  
Vanessa Neves Höpner ◽  
Volmir Eugênio Wilhelm
Keyword(s):  
Life Span ◽  
Electric Motor ◽  
Low Voltage ◽  
Frequency Converter ◽  
Rate Of Change ◽  
High Rate ◽  
Switching Frequency ◽  
Electric Motors ◽  
Frequency Converters ◽  
High Switching Frequency

The use of static frequency converters, which have a high switching frequency, generates voltage pulses with a high rate of change over time. In combination with cable and motor impedance, this generates repetitive overvoltage at the motor terminals, influencing the occurrence of partial discharges between conductors, causing degradation of the insulation of electric motors. Understanding the effects resulting from the frequency converter–electric motor interaction is essential for developing and implementing insulation systems with characteristics that support the most diverse applications, have an operating life under economically viable conditions, and promote energy efficiency. With this objective, a search was carried out in three recognized databases. Duplicate articles were eliminated, resulting in 1069 articles, which were systematically categorized and reviewed, resulting in 481 articles discussing the causes of degradation in the insulation of electric motors powered by frequency converters. A bibliographic portfolio was built and evaluated, with 230 articles that present results on the factors that can be used in estimating the life span of electric motor insulation. In this structure, the historical evolution of the collected information, the authors who conducted the most research on the theme, and the relevance of the knowledge presented in the works were considered.

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