scholarly journals Voltage Control of Multiphase Cage Induction Generators at a Speed Varying over a Wide Range

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7080
Author(s):  
Piotr Drozdowski ◽  
Dariusz Cholewa
Keyword(s):  
Output Voltage ◽  
Voltage Regulation ◽  
Magnetic Core ◽  
Induction Generator ◽  
Pwm Rectifier ◽  
Induction Generators ◽  
Phase Sequence ◽  
Wide Range ◽  
The Difference ◽  
Simultaneous Switching

The subject of this publication is a method of controlling the DC voltage of a PWM rectifier supplied by a multiphase cage induction generator with the number of stator phases greater than three operating in a wide range of driving speeds. Voltage regulation is performed by changing the frequency and amplitude of the stator voltages with simultaneous switching of the phase sequence of these voltages. The step change of the voltage sequence is made in the designated ranges of the generator speed, which enables the stabilization of the output voltage in a wide range from the minimum speed of about 25% of the rated speed. Such sequence switching changes the number of pole pairs produced by the winding for each supply sequence. The difference compared to multi-speed induction machines is that, in the presented solution, there is only one winding, not a few, which enables good use of the machine’s magnetic core in the same dimensions as for the three-phase machine of a similar power. Steady-state characteristics and dynamic operation were obtained using laboratory measurements of a standalone nine-phase induction generator. The automatic control system maintained the output voltage at the set level, regardless of the generator load and driving power.

scholarly journals AC-AC voltage regulation by switch mode PWM Cûk voltage controller with improved performance

2021 ◽  
Author(s):  
Palash K. Banerjee
Keyword(s):  
Output Voltage ◽  
Supply Voltage ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Control Circuit ◽  
Voltage Regulator ◽  
Error Signal ◽  
Constant Voltage ◽  
Wide Range ◽  
Switching Devices

In this research project, an AC Cûk voltage regulator has been proposed for maintaining constant voltage across the load during wide range of input voltage fluctuations. The proposed AC Ck voltage regulator made of practical IGBT switches has been investigated for both manual and automatic control circuit. A fraction of the output voltage is taken as the input voltage of the control circuit and produce the error signal if any changes occur in the output voltage. The modified error signal is used to make PWM signals for switching devices as per output voltage of regulator. The PWM controls the ON/OFF time (Duty cycle) of switching devices (IGBTs) of the proposed regulator. As a result the regulator is maintaining a constant voltage across the load during any change in supply voltage. The simulation waveforms and the calculated total harmonics distortion (THD) values are compared with previously studied AC Buck-Boost regulator. The observed simulated waveforms of output voltage, output current and input current and THD values have been improved in case of proposed AC Cûk voltage regulator.

Steady State Analysis Operation of Self-Excited Wound Rotor Induction Generator Under Constant Frequency and Tolerated Output Voltage

2016 ◽  
Vol 25 (06) ◽  
pp. 1650060 ◽  
Author(s):  
Selmi Mourad ◽  
Rehaoulia Habib
Keyword(s):  
Output Voltage ◽  
Frequency Control ◽  
Induction Generator ◽  
Prime Mover ◽  
Constant Frequency ◽  
Suitable Candidate ◽  
Wind Energy Conversion ◽  
Induction Generators ◽  
Rotor Resistance ◽  
The Poor

Self-excited induction generators (SEIG) are found to be most suitable candidate for wind energy conversion application required at remote windy locations. The major drawbacks of these generators are the poor voltage and frequency control under load and prime mover speed perturbations. In this paper, an attempt has been made to optimize the control strategy under various load and prime mover conditions, of the self-excited wound rotor induction generator (SEWRIG). By tolerating a slight deviation of the output voltage and ensuring a constant frequency with an adequate external rotor resistance, only four values of excitation capacitor are required for the whole range of operation. The effectiveness of the adopted strategy has been confirmed by comparing on a 0.8-[Formula: see text]kW wound rotor induction generator the simulated results to the corresponding obtained with an experimental test. A close agreement between the computed and experimental results confirms the efficiency of the adopted method.

scholarly journals Development of Brushless Claw Pole Electrical Excitation and Combined Permanent Magnet Hybrid Excitation Generator for Vehicles

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4723 ◽  
Author(s):  
Huihui Geng ◽  
Xueyi Zhang ◽  
Yufeng Zhang ◽  
Wenjing Hu ◽  
Yulong Lei ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Output Voltage ◽  
High Efficiency ◽  
Voltage Regulation ◽  
Electrical Excitation ◽  
Excitation Generator ◽  
Finite Element Software ◽  
Wide Range ◽  
Hybrid Excitation

Aiming at the problems of large excitation loss and low power generation efficiency of silicon rectifier generators and the unstable output voltage of permanent magnet (PM) generators, a hybrid excitation generator (HEG) with suspended brushless claw pole electrical excitation rotor (EER) and combined magnetic pole PM rotor is proposed in the present work. With only one fractional slot winding stator, the generator adopts PM field as the main magnetic field and electrical excitation field as the auxiliary magnetic field, which not only retains the advantages of high efficiency of PM generators but also effectively reduces excitation consumption. The main structure parameters and the design method were analyzed, and a simulation analysis of no-load magnetic field distribution and flux regulation ability was carried out using finite element software to verify the rationality of the hybrid excitation parallel magnetic circuit design. Moreover, the no-load, load, regulation, and voltage regulation characteristics of the designed generator were tested, and the results show that the designed generator has a wide range of voltage regulation, which can ensure stable output voltage under variable speed and load conditions.

Behaviour of single-phase self-excited induction generator during short-circuit at terminals

2018 ◽  
Vol 37 (5) ◽  
pp. 1815-1823
Author(s):  
Krzysztof Makowski ◽  
Aleksander Leicht
Keyword(s):  
Output Voltage ◽  
Design Methodology ◽  
Single Phase ◽  
Short Circuit ◽  
Voltage Regulation ◽  
Circuit Model ◽  
Field Analysis ◽  
Induction Generator ◽  
Content Type ◽  
Current Drop

PurposeThe purpose of this paper is to present analysis of short-circuit transients in a single-phase self-excited induction generator (SP-SEIG) for different capacitor topologies.Design/methodology/approachThe paper presents field analysis of the short-circuit problem in the SP-SEIG on the base of two-dimensional field-circuit model of the generator.FindingsThe carried-out field computations of the tested SP-SEIG show that the self-excited induction generator is intrinsically protected from the results of sudden short-circuit, as output voltage and current drop rapidly to zero. Short-circuit is a problem when a series capacitor is used to improve output voltage regulation. Experimental results show that re-excitation of the generator is possible after the short-circuit is removed.Originality/valueThe originality of the paper is the presented analysis of short-circuit transients at terminals of SP-SEIG. A finite elements method-based field circuit model was used. The simulation results were validated by the measurements conducted on a laboratory test setup.

scholarly journals Stability Domain Analysis and Enhancement of Squirrel Cage Induction Generator Wind Turbines in Weak Grids

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4786
Author(s):  
Jonathan Devadason ◽  
Paul S. Moses ◽  
Mohammad A. S. Masoum
Keyword(s):  
Stability Domain ◽  
Power Grids ◽  
Induction Generator ◽  
Series Compensation ◽  
Induction Generators ◽  
Squirrel Cage ◽  
R Ratio ◽  
Space Modeling ◽  
Wide Range ◽  
The Stability

There are significant concerns regarding the stability of increased wind power generation in weak power grids. This paper investigates and improves the stability of Wind Turbine Squirrel Cage Induction Generators (WT-SCIGs) with series compensation and weak interconnections to the power grid. Detailed time-domain and state-space modeling have revealed new bifurcations and oscillatory modes for a WT-SCIG connected radially to a weak grid through a series compensated line. The stability domain analyses are carried out by computing bifurcations in the system by analyzing eigenvalues of the linearized system. The analyses demonstrate for the first time how the degree of compensation at which the Hopf bifurcation occurs depends on the X/R ratio of the line, operating slip of the induction generator, and voltage regulator parameters as well as the time delays in measurements. A new damping controller is proposed, which greatly improves the dynamic stability of the WT-SCIG and eliminates destructive Hopf bifurcations in weak grids for a wide range of series compensation. This allows for a much larger percentage of series compensation than what is usually possible, while avoiding instabilities, thereby maximizing the power transfer capability.

scholarly journals High Efficiency Isolated On-Board EV Battery Charger Using LLC Resonant Converter

2021 ◽  
Author(s):  
Sevilay Cetin ◽  
Keyword(s):  
Output Voltage ◽  
High Efficiency ◽  
Load Condition ◽  
Voltage Regulation ◽  
Resonant Converter ◽  
Battery Charger ◽  
Voltage Range ◽  
Wide Range ◽  
Electrical Vehicle ◽  
Llc Resonant Converter

In this study, high efficiency design of an on-board Electrical Vehicle (EV) battery charger is presented. The presented charger has two stages where the first stage is conventional front-end boost converter and the second stage is LLC resonant converter. The basic principles of both stage are discussed and the detailed design procedures are presented in terms of wide range output voltage regulation, wide range load condition, high efficiency and high power density. The presented design approach is tested with a prototype implemented with 2.5 kW output power at 250 V-450 V output voltage range. The peak efficiency of system is obtained as 95.53% at full load condition.

scholarly journals AC-AC voltage regulation by switch mode PWM Cûk voltage controller with improved performance

2021 ◽  
Author(s):  
Palash K. Banerjee
Keyword(s):  
Output Voltage ◽  
Supply Voltage ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Control Circuit ◽  
Voltage Regulator ◽  
Error Signal ◽  
Constant Voltage ◽  
Wide Range ◽  
Switching Devices

In this research project, an AC Cûk voltage regulator has been proposed for maintaining constant voltage across the load during wide range of input voltage fluctuations. The proposed AC Ck voltage regulator made of practical IGBT switches has been investigated for both manual and automatic control circuit. A fraction of the output voltage is taken as the input voltage of the control circuit and produce the error signal if any changes occur in the output voltage. The modified error signal is used to make PWM signals for switching devices as per output voltage of regulator. The PWM controls the ON/OFF time (Duty cycle) of switching devices (IGBTs) of the proposed regulator. As a result the regulator is maintaining a constant voltage across the load during any change in supply voltage. The simulation waveforms and the calculated total harmonics distortion (THD) values are compared with previously studied AC Buck-Boost regulator. The observed simulated waveforms of output voltage, output current and input current and THD values have been improved in case of proposed AC Cûk voltage regulator.

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