No-load voltage waveform optimization and damper bars heat reduction of tubular hydro-generator by adjusting damper bar pitch and skewing stator slot

2011 ◽  
Author(s):  
Zhen-nan Fan ◽  
Li-dan Xie ◽  
Guang-hou Zhou
Keyword(s):  
Voltage Waveform ◽  
Load Voltage ◽  
Waveform Optimization

No-Load Voltage Waveform Optimization of Integral Number Slots Large Hydro-Generator by Increase the Number of Damper Bars per Pole

2013 ◽  
Vol 756-759 ◽  
pp. 3909-3913
Author(s):  
Zhi Gang Zhang ◽  
Zhen Nan Fan
Keyword(s):  
Electromagnetic Field ◽  
Coupling Model ◽  
Voltage Waveform ◽  
Load Voltage ◽  
Electric Network ◽  
Design Standard ◽  
Waveform Optimization ◽  
Integral Number

In order to analyze the influence of integral-number slots large hydro-generator no-load voltage waveform by the number of damper bars per pole increase, the 2D moving electromagnetic field-circuit coupling model is established, and the no-load voltage waveforms of a 600MW integral-number slots hydro-generator are calculated and analyzed. The results show that the harmonics are weakened and the waveforms of the no-load voltage are improved observably when reasonable increase the number of the damper bars per pole. The research is helpful for improving design standard and enhancing the operation reliability of the large hydro-generator and electric network.

No-Load Voltage Waveform Optimization of Integral Number Slots Large Hydro-Generator by Shift Damper Winding

2013 ◽  
Vol 765-767 ◽  
pp. 8-12
Author(s):  
Hong Lian Wang ◽  
Zhen Nan Fan
Keyword(s):  
Electromagnetic Field ◽  
Coupling Model ◽  
Voltage Waveform ◽  
Load Voltage ◽  
Design Standard ◽  
Waveform Optimization ◽  
Integral Number ◽  
Damper Winding

In order to analyze the influence of integral-number slots large hydro-generator no-load voltage waveform by the damper winding shift schemes, the 2D moving electromagnetic field-circuit coupling model is established, and the no-load voltage waveforms of a 600MW integral-number slots hydro-generator are calculated and analyzed. The results show that the tooth harmonics are weakened and the waveforms of the no-load voltage are improved observably when damper winding shift scheme adopted. The research is helpful for improving design standard and enhancing the operation reliability of the large hydro-generator.

Failure Analysis and No-Load Voltage Waveform Optimization and Damper Bar Heat Reduction of a Large Tubular Hydro-Generator

2014 ◽  
Vol 488-489 ◽  
pp. 834-838
Author(s):  
Jian Gao ◽  
Zhen Nan Fan
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Failure Analysis ◽  
Test Data ◽  
Fe Model ◽  
Optimized Design ◽  
Voltage Waveform ◽  
Load Voltage ◽  
Waveform Optimization ◽  
Calculation Results

For the failures of a 30MW tubular hydro-generator such as no-load voltage waveform is bad, damper bars are over heat, a multi-slice moving electromagnetic field-circuit coupling FE model of tubular hydro-generator and a 3D temperature field FE model of the rotor are built respectively.And the computations about the failure reasons and the optimized design schemes are implemented and analyzed by these modles.And the calculation results are coincident well with the test data.

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.

Waveform optimization of a two-axis smooth impact drive mechanism actuator

2020 ◽  
pp. 1045389X2095126 ◽  
Author(s):  
Jianxiang Wang ◽  
Yuxi Chen ◽  
Yuxin Peng ◽  
Xian Song ◽  
Yangkun Zhang ◽  
...  
Keyword(s):  
Short Term Memory ◽  
Maximum Velocity ◽  
Input Voltage ◽  
Data Driven ◽  
Voltage Waveform ◽  
Drive Mechanism ◽  
Waveform Optimization ◽  
Piezoelectric Elements ◽  
Long Short Term Memory ◽  
Optimum Input

This paper presents a data-driven method for waveform optimization of a two-axis smooth impact drive mechanism (SIDM) actuator. The actuator was constructed by two piezoelectric elements (PZTs) perpendicularly fixed to an L-shaped base for two-axis positioning. An XY stage was designed and constructed by assembling the two-axis SIDM actuator. The XY stage could position long motion ranges of several millimeters with nanometer-level resolution, and the size was confined to be 20 mm (X) × 20 mm (Y) × 4.5 mm (H). The data-driven method based on the long short-term memory (LSTM) neural networks was used to predict the optimum input voltage waveform of the actuator. With the optimized input voltage waveform, it was verified that the maximum velocity of the stage could be improved about two times.

scholarly journals Actuating Voltage Waveform Optimization of Piezoelectric Inkjet Printhead for Suppression of Residual Vibrations

Micromachines ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 900
Author(s):  
Muhammad Ali Shah ◽  
Duck-Gyu Lee ◽  
Bo Yeon Lee ◽  
Nam Woon Kim ◽  
Hyojin An ◽  
...  
Keyword(s):  
Dwell Time ◽  
Voltage Amplitude ◽  
Optimal Parameters ◽  
Voltage Waveform ◽  
Tuning Time ◽  
Waveform Optimization ◽  
Lumped Element ◽  
Bipolar Voltage ◽  
Inkjet Printhead ◽  
Rising Time

After a piezoelectric inkjet printhead jets the first droplet, the actuating membrane still vibrates, creating residual vibrations in the ink channel, which can degrade the inkjet printhead performance. For suppressing these vibrations, an optimized actuating voltage waveform with two pulses must be obtained, of which the first pulse is used for jetting and the second pulse is used to suppress the residual vibrations. In this study, the pressure history within the ink channel of a recirculating piezoelectric inkjet printhead was first acquired using lumped element modeling. Then, for suppressing residual vibrations, a bipolar voltage waveform was optimized via analysis of the tuning time (tt ), dwell time (td2), rising time (tr2), falling time (tf2), and voltage amplitude of the second pulse. Two voltage waveforms, Waveform 01 and Waveform 02, were optimized thereafter. In Waveform 01, tt=2 μs, td2=2 μs, and tr2 and tf2=1 μs were finalized as the optimal parameters; in the case of another waveform, the optimal parameters of td2, tr2, and tf2 were found to be 4, 1, and 1 μs, respectively. The optimal voltage amplitude of the second pulse was found to be 1/3 the amplitude of the first pulse. On the basis of our analysis, the tuning time in Waveform 01 is the most sensitive parameter, and the performance yielded is even poorer than that yielded by standard waveform, if not optimized. Therefore, the other waveform is recommended for the suppression of residual vibrations.

Optimization of No-Load Voltage Waveform in a Large Hydro-Generator by the Schemes which Shift the Damper Winding and Skew Stator Slots

2012 ◽  
Vol 614-615 ◽  
pp. 397-403
Author(s):  
Yong Gang Luo ◽  
Zhen Nan Fan
Keyword(s):  
Electromagnetic Field ◽  
Test Data ◽  
Coupling Model ◽  
Voltage Waveform ◽  
Load Voltage ◽  
Electric Network ◽  
Design Standard ◽  
Design Scheme ◽  
Calculation Results ◽  
Damper Winding

Improvement of no-load voltage waveform is a important problems for designing hydro-generators and ensuring operation reliability of the generators and electric network. The no-load voltage waveforms of a 335MW hydro-generator are optimized with the design scheme which shift damper winding and skew stator slots, and the computations are implemented and analyzed by the multi-slice moving electromagnetic field-circuit coupling model of the hydro-generator The results show that the waveforms of the no-load voltage are improved observably when reasonable shift damper winding and skewing stator slots. The calculation results are coincident well with the test data. The research is helpful for improving design standard and enhancing the operation reliability of the large hydro-generator and electric network.

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.

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