scholarly journals The Tesla transformer output voltage with an operating frequency deflection from the resonant value. Purpose

2018 ◽  
Vol 0 (36) ◽  
pp. 187-194
Author(s):  
Yu. V. Batygin ◽  
E. О. Chaplygin ◽  
S. О. Shynderuk ◽  
E. О. Tretinnikov
Keyword(s):  
Output Voltage ◽  
Operating Frequency ◽  
Tesla Transformer ◽  
Transformer Output

Frequency Stabilization and EMI Noise Reduction of COT Method Ripple-Controlled Switching Converters with Output Voltage Ripple Cancellation

2020 ◽  
Vol 38 ◽  
pp. 130-142
Author(s):  
Yasunori Kobori ◽  
Yi Fei Sun ◽  
Minh Tri Tran ◽  
Anna Kuwana ◽  
Haruo Kobayashi
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Peak Level ◽  
Operating Frequency ◽  
Duty Ratio ◽  
Switching Converters ◽  
Clock Frequency ◽  
Voltage Ripple ◽  
Ripple Cancellation ◽  
Emi Reduction

This paper proposes a new EMI reduction and automatic ripple cancellation technique about the ripple-controlled converter with the ripple injection and Constant-On Time (COT) method. The ripple-controlled converters have no stable clock and it is difficult to reduce the EMI noise by shaking the operating frequency. The new method of EMI reduction is that the COT pulse width is modulated by the triangular signal so that the operating frequency is modulated and the spectrum peak level of the clock frequency is greatly reduced. But the output voltage ripple is much increased because of the change of the duty ratio of the operating frequency. The increaced ripple is canceled by adding the modulation signal to the ripple injection circuit. Moreover stabiliztion of the operating frequency on Discontinuous Conduction Mode (DCM) is reported. The operating frequency falls down on DCM mode in the COT converters. To stabilize the operating frequency, cheking the operating period is fedback to control the COT pulse width

EMI Reduction of PFC Rectifier and LLC Converter with Automatic Output Ripple Improvement

2020 ◽  
Vol 38 ◽  
pp. 103-117
Author(s):  
Yasunori Kobori ◽  
Noriyuki Oiwa ◽  
Shogo Katayama ◽  
Ahmad Bustoni ◽  
Yi Fei Sun ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Power Factor ◽  
Output Voltage ◽  
Clock Pulse ◽  
Operating Frequency ◽  
Duty Ratio ◽  
Clock Frequency ◽  
Forward Converter ◽  
Electro Magnetic ◽  
Emi Reduction

This paper proposes the method of the Electro-Magnetic Interference (EMI) noise reduction of the AC-DC rectifiers and the DC-DC converters with the insulated transformers. For the Power Factor Correction (PFC) rectifier, the power factor is the most important item, but the EMI noise emitted from the clock pulse is not remarked. For the DC-DC converters such as the forward converter, the efficiency is the most important. We have focused on the EMI noise reduction for the PFC rectifier and insulated DC-DC converters with the frequency modulation of the clock pulses. First, the spectrum level of the clock pulse is introduced to be much reduced by shaking the clock frequency for the PFC rectifier and the forward converter. Next, we have investigated the EMI reduction of the LLC converter whose operating frequency varies to make the output voltage stable. It is difficult to modify the operating frequency to reduce the EMI noise. We have investigated to reduce the EMI noise by shaking the duty ratio of the resonant signals for the LLC converter. In this case, the output voltage ripple is increased by much EMI noise reduction. Finally, the technology to stabilize the increased ripple is introduced.

scholarly journals Current-pumping performance of axial-symmetric superconducting dynamo designs

2021 ◽  
Author(s):  
◽  
Sin Hoi Phang
Keyword(s):  
Liquid Nitrogen ◽  
Output Voltage ◽  
Short Circuit ◽  
Local Heating ◽  
Open Circuit ◽  
Experimental Results ◽  
Operating Frequency ◽  
Design Parameters ◽  
Dynamic Resistance ◽  
Frequency Regime

<p>In this project, the current pumping performances of three high temperature superconducting (HTS) dynamos (mechanically-rotating flux pumps) were investigated. These flux pumps (FPs) were identified as the Gen 1, Gen 2 and Gen 4 FP respectively. They were modelled using simple DC equivalent circuits and their performances were defined by three output parameters: DC open-circuit voltage (Voc), dynamic resistance (Rd) and DC short-circuit current (Isc). The experimental results showed that these FPs produced non-zero DC output voltages across their stators and each supplied DC output currents into series connected superconducting circuits.  The Gen 1 FP was cooled with liquid nitrogen and operated at 77 K. The stators were made from 12-mm wide copper-coated yttrium barium copper oxide (YBCO) HTS conductors. The objective of the experiment was to investigate the effect of the rotor magnet size, geometry and orientation (with respect to the stators) on the FP performance. The design parameters, based on the width and the length of the magnet with respect to the stator, for optimal FP performance were determined.  The Gen 2 FP was also cooled with liquid nitrogen and operated at 77 K. The stators were made from 46-mm wide Ag-coated YBCO HTS conductors. The objective of the experiment was to investigate the effect of stator width on the FP performance at various magnet frequencies. This was done by slitting two of the stators to form parallel stators with equal width, but smaller than the original conductor width. The experimental results showed that the FP performance was highly dependent on the operating frequency. Three operating frequency regimes were observed: low, mid and high. At high frequency, the Voc decreased and the Rd increased signifcantly. This was attributed to the local heating effect in the stator due to the increase in the current density. As a result, the FP produced zero output current in this regime. The AC voltage waveforms measured across the stators in different frequency regimes were very different in shapes and amplitudes. Therefore, these waveforms can be used to identify the operating frequency regime of the FP. At some operating frequencies in the mid frequency regime, bi-stable operating modes were observed, each mode resulted in different output parameters.  The Gen 4 FP was constructed in this project. It was cooled via thermal conduction method using a cryorefrigerator system. It had an axial-symmetric stator design where the shape of the stator is cylindrical. The width of the stator was considerably larger compared with the Gen 1 and Gen 2 FPs. The experiment objective was to investigate whether this design would produce a DC current, and then characterise the FP performance at different operating temperatures. The experimental results showed that the time-averaged DC output voltage of the Gen 4 FP was much higher compared with the Gen 1 and Gen 2 FPs. The reason is that it produced a DC output voltage for almost the entire rotor cycle. The experimental results also indicated that the Gen 4 FP has the capability to produce output currents in the kA range.</p>

scholarly journals Study of the operating modes of the high voltage power source for barrier type discharge excitation

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 46-51
Author(s):  
A. L. Barakhoev ◽  
O. I. Tikhon ◽  
V. V. Tuboltsev
Keyword(s):  
High Voltage ◽  
Atmospheric Pressure ◽  
Output Voltage ◽  
Current Mode ◽  
Voltage Divider ◽  
Power Source ◽  
Operating Frequency ◽  
Switching Frequency ◽  
Lc Circuit ◽  
Barrier Type

The issues related to the features of operation and modes setting of a high-voltage switching power source based on a sequential autonomous resonant inverter with reverse diodes used to excite an atmospheric pressure barrier type discharge are discussed in the article. It is indicated that the characteristic features of the autonomous resonant inverters operation are the occurrence of damped voltage fluctuations in the LC circuit of the inverter, as well as the dependence of the output alternating voltage on the ratio of the inverter operating frequency (thyristor switching frequency) to the natural resonant frequency of the LC circuit. Depending on this ratio, the inverter can operate in discontinuous, boundary and continuous current mode. The amplitude and shape of the inverter output voltage were controlled using a 1:1000 voltage divider with a C1-65A oscilloscope. The shape of the gate trigger pulses was obtained using a C1-167 oscilloscope. It is established that when the gate trigger pulses are asymmetrical relative to each other due to the operation features of the step-up transformers, the value of the alternating high-voltage at the inverter output is insufficient to excite the atmospheric pressure barrier type discharge. In the case of the gate trigger pulses symmetry, the output voltage of the inverter stage reaches the values required for the breakdown of the dielectric medium. Oscillograms of the inverter output voltage while adjusting its operating frequency are obtained. It is shown that the amplitude value of the voltage at the gas-discharge load increases as the operating frequency of the inverter increases. For the gate trigger pulses frequency of 250 Hz the value of the inverter output voltage amplitude was 3.4 kV, for 460 Hz – 4.0 kV, and for 550 Hz – 4.2 kV.

scholarly journals Current-pumping performance of axial-symmetric superconducting dynamo designs

2021 ◽  
Author(s):  
◽  
Sin Hoi Phang
Keyword(s):  
Liquid Nitrogen ◽  
Output Voltage ◽  
Short Circuit ◽  
Local Heating ◽  
Open Circuit ◽  
Experimental Results ◽  
Operating Frequency ◽  
Design Parameters ◽  
Dynamic Resistance ◽  
Frequency Regime

<p>In this project, the current pumping performances of three high temperature superconducting (HTS) dynamos (mechanically-rotating flux pumps) were investigated. These flux pumps (FPs) were identified as the Gen 1, Gen 2 and Gen 4 FP respectively. They were modelled using simple DC equivalent circuits and their performances were defined by three output parameters: DC open-circuit voltage (Voc), dynamic resistance (Rd) and DC short-circuit current (Isc). The experimental results showed that these FPs produced non-zero DC output voltages across their stators and each supplied DC output currents into series connected superconducting circuits.  The Gen 1 FP was cooled with liquid nitrogen and operated at 77 K. The stators were made from 12-mm wide copper-coated yttrium barium copper oxide (YBCO) HTS conductors. The objective of the experiment was to investigate the effect of the rotor magnet size, geometry and orientation (with respect to the stators) on the FP performance. The design parameters, based on the width and the length of the magnet with respect to the stator, for optimal FP performance were determined.  The Gen 2 FP was also cooled with liquid nitrogen and operated at 77 K. The stators were made from 46-mm wide Ag-coated YBCO HTS conductors. The objective of the experiment was to investigate the effect of stator width on the FP performance at various magnet frequencies. This was done by slitting two of the stators to form parallel stators with equal width, but smaller than the original conductor width. The experimental results showed that the FP performance was highly dependent on the operating frequency. Three operating frequency regimes were observed: low, mid and high. At high frequency, the Voc decreased and the Rd increased signifcantly. This was attributed to the local heating effect in the stator due to the increase in the current density. As a result, the FP produced zero output current in this regime. The AC voltage waveforms measured across the stators in different frequency regimes were very different in shapes and amplitudes. Therefore, these waveforms can be used to identify the operating frequency regime of the FP. At some operating frequencies in the mid frequency regime, bi-stable operating modes were observed, each mode resulted in different output parameters.  The Gen 4 FP was constructed in this project. It was cooled via thermal conduction method using a cryorefrigerator system. It had an axial-symmetric stator design where the shape of the stator is cylindrical. The width of the stator was considerably larger compared with the Gen 1 and Gen 2 FPs. The experiment objective was to investigate whether this design would produce a DC current, and then characterise the FP performance at different operating temperatures. The experimental results showed that the time-averaged DC output voltage of the Gen 4 FP was much higher compared with the Gen 1 and Gen 2 FPs. The reason is that it produced a DC output voltage for almost the entire rotor cycle. The experimental results also indicated that the Gen 4 FP has the capability to produce output currents in the kA range.</p>

scholarly journals Improvements to Secondary Windings of Tesla Transformers

2017 ◽  
Vol 9 (1) ◽  
pp. 93
Author(s):  
Richard M Craven ◽  
Ivor R Smith ◽  
Bucur M Novac
Keyword(s):  
Power Systems ◽  
Higher Order ◽  
Primary Circuit ◽  
Current Response ◽  
Secondary Circuit ◽  
Electronic Warfare ◽  
Higher Order Modes ◽  
Tesla Transformer ◽  
Transformer Output ◽  
Secondary Winding

Impulse excitation of the tuned primary circuit of a Tesla transformer generates a voltage and current response in the similarly tuned secondary circuit that contains both a fundamental component and a series of multiple higher-order modes. This paper investigates the most significant of these modes, in order to demonstrate a design approach that, when applied to the secondary winding, can bring about a reduction in the higher-order modes without significantly affecting the fundamental term. The resulting process leads to an improved spectral purity of the transformer output, making it better suited than existing conventional designs for application in electronic warfare and other high-power systems.

scholarly journals Optimum transfer characteristics of the Tesla transformer on the first and second half-waves of output voltage

2021 ◽  
Vol 2064 (1) ◽  
pp. 012130
Author(s):  
V Kladukhin ◽  
S Khramtsov
Keyword(s):  
Exact Solution ◽  
Output Voltage ◽  
Secondary Circuit ◽  
Capacitive Storage ◽  
Transfer Characteristics ◽  
Tesla Transformer ◽  
Resonance Frequencies ◽  
Natural Resonance ◽  
Generalized Parameters ◽  
Q Factors

Abstract The elements of the theory of the Tesla transformer are stated, the exact solution of the equations of the dynamics of currents and voltages in the transformer circuits through the generalized parameters of the circuits (Q-factors of the primary and secondary circuits, the coupling coefficient of the circuits and mismatching factor of the natural resonance frequencies of the circuits) is given, under the assumption of their constancy. The optimal transfer characteristics of the processes of charging the capacitive storage of the secondary circuit of the transformer on the first and second half-waves are given, demonstrating the capabilities of the Tesla transformer.

Sign in / Sign up

Export Citation Format

Share Document