No-Load Voltage Waveform Computation of the Different Design Schemes of Stator Slots Skewing Degree of Tubular Hydro-Generator

2015 ◽  
Vol 1092-1093 ◽  
pp. 296-299
Author(s):  
De Wei Zhang ◽  
Zhen Nan Fan
Keyword(s):  
Harmonic Distortion ◽  
Voltage Waveform ◽  
Distortion Factor ◽  
Load Voltage ◽  
Waveform Distortion ◽  
Design And Manufacture ◽  
Fractional Slot

To reduce the tubular hydro-generator no-load voltage waveform distortion,some different design schemes of stator slot skewing degree in a 36MW fractional slot tubular hydro-generator (q=11/2 ) are calculated and compared. Then, the relation of the no-load voltage waveform harmonic distortion factor (HDF) and stator slot skewing degree are revealed. The research provides the important reference informations for the optimization of no-load voltage waveform , and it is helpful for improving the industral design and manufacture standard of tubular hydro-generator.

Research of Simulation in the Main Circuit of Static Var Generator Based on Cascade H-Bride

2013 ◽  
Vol 392 ◽  
pp. 409-412
Author(s):  
Xian Bin Dai ◽  
Xiao Hua Yuan ◽  
Wei Du
Keyword(s):  
Output Voltage ◽  
Power Index ◽  
Matlab Simulation ◽  
Voltage Waveform ◽  
Distortion Factor ◽  
Harmonic Content ◽  
Three Phase ◽  
Static Var Generator ◽  
Waveform Distortion ◽  
Working Principle

This paper introduces the working principle of the research of simulation in the main circuit of Static Var Generator based on Cascade H-Bride and takes the three-phase Static Var Generator based on cascade H-Bride with rated capacity 10kVar,rated voltage 380V for example to proceed the MATLAB simulation. The research shows that the more amount of cascade H-Bride, the more number of output voltage levels in the main circuit of Static Var Generator, the smaller value of voltage waveform distortion factor, and the less harmonic content be inject in electric network, which improves power index.

scholarly journals Effect of Damper Winding and Stator Slot Skewing Structure on No-Load Voltage Waveform Distortion and Damper Bar Heat in Large Tubular Hydro Generator

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 22281-22291 ◽  
Author(s):  
Zhen-Nan Fan ◽  
Li Han ◽  
Yong Liao ◽  
Li-Dan Xie ◽  
Kun Wen ◽  
...  
Keyword(s):  
Voltage Waveform ◽  
Load Voltage ◽  
Waveform Distortion ◽  
Damper Winding

scholarly journals A New Approach to the PWM Modulation for the Multiphase Matrix Converters Supplying Loads with Open-End Winding

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 466
Author(s):  
Pawel Szczepankowski ◽  
Natalia Strzelecka ◽  
Enrique Romero-Cadaval
Keyword(s):  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Simulation Software ◽  
Common Mode ◽  
New Approach ◽  
Matrix Converters ◽  
Load Voltage ◽  
Common Mode Voltage ◽  
The Common ◽  
Open End Winding

This article presents three variants of the Pulse Width Modulation (PWM) for the Double Square Multiphase type Conventional Matrix Converters (DSM-CMC) supplying loads with the open-end winding. The first variant of PWM offers the ability to obtain zero value of the common-mode voltage at the load’s terminals and applies only six switches within the modulation period. The second proposal archives for less Total Harmonic Distortion (THD) of the generated load voltage. The third variant of modulation concerns maximizing the voltage transfer ratio, minimizing the number of switching, and the common-mode voltage cancellation. The discussed modulations are based on the concept of sinusoidal voltage quadrature signals, which can be an effective alternative to the classic space-vector approach. In the proposed approach, the geometrical arrangement of basic vectors needed to synthesize output voltages is built from the less number of vectors, which is equal to the number of the matrix converter’s terminals. The PWM duty cycle computation is performed using only a second-order determinant of the voltages coordinate matrix without using trigonometric functions. A new approach to the PWM duty cycles computing and the load voltage synthesis by 5 × 5 and 12 × 12 topologies has been verified using the PSIM simulation software.

Open Loop Stability on Hybrid Synchronous Motor

2010 ◽  
Vol 121-122 ◽  
pp. 860-865
Author(s):  
Xue Zhen Chen
Keyword(s):  
Permanent Magnet ◽  
Harmonic Distortion ◽  
Synchronous Motor ◽  
Open Loop ◽  
Mathematics Model ◽  
Distortion Factor ◽  
Part D ◽  
Fraction Length ◽  
The Stability ◽  
Loop Stability

This paper searched open loop stability on hybrid synchronous motor which is made of a permanent magnet part and a reluctance part, there is important influence for the ratio k, the fraction length of the permanent magnet part, and the displaced angle α, the between the two part d-axis, the small-signal mathematics model was derived based on d-q reference frame, and optimized the appropriate k and α value considering the stability and the harmonic distortion factor (THD), The simulation results show that the model is correct.

scholarly journals Research on Output Waveform of Generator with Rectifier Load considering Commutation Overlap Angle

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bingyi Zhang ◽  
Gongfei He ◽  
Guihong Feng
Keyword(s):  
Circuit Simulation ◽  
Harmonic Distortion ◽  
Simulation Method ◽  
Conduction Time ◽  
Current Waveform ◽  
Voltage Waveform ◽  
Rectifier Circuit ◽  
Output Waveform ◽  
Output Side ◽  
Distortion Rate

The purpose of this paper is to study the influence of the uncontrolled rectifier circuit on the generator’s output waveform when considering the commutation overlap angle. Taking the nonsalient permanent magnet (PM) generator directly connected with the uncontrolled rectifier circuit as an example, the equivalent circuit of the generator with rectifier load is established, and the commutation process of the rectifier circuit is analyzed when the effect of the commutation overlap angle is considered. The output waveforms of generator’s output side are obtained by analytical method, circuit simulation method, field-circuit coupled simulation method, and experimental method. The validity of the analysis methods is demonstrated by comparison. According to the results of analytical analysis, we know the characteristics of the output waveform under the influence of the commutation overlap angle. The existence of the commutation overlap angle will cause the voltage waveform to concave or convex, prolong the conduction time of the winding, and result in phase difference between the voltage waveform and current waveform. The influence of synchronous inductance and extra inductance on the output waveforms and harmonic distortion rate is analyzed. The research of this paper provides a theoretical basis for improving the output waveform of the generator with rectifier load.

Simulation and Analysis of Novel Extendable Multilevel Inverter Topology

2019 ◽  
Vol 28 (06) ◽  
pp. 1950089 ◽  
Author(s):  
V. Thiyagarajan ◽  
P. Somasundaram ◽  
K. Ramash Kumar
Keyword(s):  
Single Phase ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Voltage Waveform ◽  
Dc Voltage ◽  
Switching Losses ◽  
Comparison Results ◽  
Symmetrical Condition ◽  
Gate Driver ◽  
Inverter Topology

Multilevel inverter (MLI) has become more popular in high power, high voltage industries owing to its high quality output voltage waveform. This paper proposes a novel single phase extendable type MLI topology. The term ‘extendable’ is included since the presented topology can be extended with maximum number of dc voltage sources to synthesize larger output levels. This topology can be operated in both symmetrical and asymmetrical conditions. The major advantages of the proposed inverter topology include minimum switching components, reduced gate driver circuits, less harmonic distortion and reduced switching losses. The comparative analysis based on the number of switches, dc voltage sources and conduction switches between the proposed topology and other existing topologies is presented in this paper. The comparison results show that the proposed inverter topology requires fewer components. The performance of the proposed MLI topology has been analyzed in both symmetrical and asymmetrical conditions. The simulation model is developed using MATLAB/SIMULINK software to verify the performance of the proposed inverter topology and also the feasibility of the presented topology during the symmetrical condition has been validated experimentally.

The No-Load Voltage Waveform and Damper Bar Temperature Computation of Integral Number Slots Large Hydro-Generator which the Number of Damper Bars per Pole Increased

2014 ◽  
Vol 488-489 ◽  
pp. 843-846
Author(s):  
Ru Yang ◽  
Hong Jun Li ◽  
Zhen Nan Fan
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Coupling Model ◽  
Fe Model ◽  
Voltage Waveform ◽  
Load Voltage ◽  
Electric Network ◽  
Design Standard ◽  
Integral Number

In order to analyze the no-load voltage waveform and damper bars temperature of integral number slots large hydro-generator which the number of damper bars per pole increased, the 2D moving electromagnetic field-circuit coupling model of a 600MW integral number slots hydro-generator and 3D temperature field FE model of the rotor are established, and the no-load voltage waveforms and temperature are calculated. The research is helpful for improving design standard and enhancing the operation reliability of the large hydro-generator and electric network.

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