平成 30 年電気学会産業応用部門大会

Y-20

Development of High-Speed and High-Voltage
Pulse Generator Using Multi-Toroidal-Core Transformer
Hafidz Elmana*, and Toshihiko Noguchi (Shizuoka University)
Keywords:

DC/DC converter, NOx decomposition, high-speed and high-voltage pulse generator

I.

INTRODUCTION

IV.

This paper focuses on a low-temperature plasma NOx
decomposition method, and an application of power electronics
is attempted to generate ultra-high-speed and high-voltage
pulse for the plasma reactor. There have been many methods
reported to decompose NOx such as a low-temperature plasma
decomposition method using corona discharge [1]. The paper
discusses practical implementation techniques to reduce theline inductance, to achieve simultaneous high-speed switchingof multiple parallel-connected MOSFETs, and to make thecompact mechanical configuration possible.
II.

REFERENCES[1]

N. Tsuji and S. Kondo, “Development of High Efficiency Low-Voltage /High-Current DC Power Supply,” IEEJ Semiconductor Power
Conversion Technical Meeting, SPC-03-141, 2003, pp. 45-50.

PROTOTYPE DESIGN

Fig. 1 shows a main circuit schematic diagram of the highspeed and high-voltage pulse generator. The voltage isstepped up through the first stage from 12 VDC to 420 VDC.
On the second stage, MOSFETs Q1-Q12 are employed toachieve simultaneous switching, and are connected to theprimary windings of the toroidal multi-core transformer. The
total voltage step-up ratio of the second stage is 24 times. The
following equations are used for the design of the toroidal
multi-core transformer:

VB = 12 V, V1 = 420 V, V2 = 10 kVFig. 1. Configuration of main circuit.
12(1)
(2)

where V1 is a primary voltage, V2 is a secondary voltage, N1 isa primary number of turns, N2 is a secondary number of turns,
Bm is magnetic flux density, S is a section area of each toroidal
core, f is an operating frequency, n is a toroidal core count. The
peak voltage of the output pulse can be determined by the turnratio of the transformer and the number of the toroidal cores.

Output voltage (kV)

2Bm SN1 f , andD
2V2  n Bm SN2 f ,DV1 

10864
20Fig. 2.

COMPUTER SIMULATION TEST RESULTS0204060Time (ns)

80

100

Simulation result of output pulse transient behavior.

14

It is required to satisfy the voltage rise time less than 100 ns
to the peak over 10 kV to increase the NOx decomposition rate.
Fig. 2 shows a computer simulation test result to check theinfluence of the line inductance. It can be found from Fig. 2that the output voltage can achieve more than 10 kV within 50
ns which implies that the proposed design has low internalinductance. An output voltage pulse train waveform is shownin Fig. 3. It is confirmed from this result that 1-ms cyclic
voltage pulse with as fast rise time as 50 ns and as high voltage
as 10 kV is obtained.

［ Y - 20 ］

12Output voltage (kV)III.

CONCLUSION

This paper discussed a compact high-speed and high-voltage
pulse generator for a NOx decomposition plasma reactor. It has
been confirmed through several computer simulation tests thatthe pulse generator prototype achieved as fast-rise-time as 50ns and as high-voltage as 12 kV.

10864
200Fig. 3.

0.5

11.5Time (ms)22.5

3Simulation result of voltage pulse train waveform.

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