Download A Trigger System with High Voltage Isolation for

A
PRESENTATION
ON
A TRIGGER SYSTEM WITH HIGH VOLTAGE ISOLATION FOR
MULTIPLE SWITCHING DEVICES
by
S K Rai
Assistant Professor
Electronics Engineering Department
B K Birla Institute of Engineering & Technology
(BKBIET)
Pilani (Raj.)-333 031
Authors: S K Rai, P Tandon, S Jangid & Rahul Varma
Defining Problem:
The semiconductor switches are the main elements of all kind of power
converters or pulse power supply design.
So, the trigger pulses to control these switches play most important role
in these designs.
There are a number of research papers related to these designs based on
different topologies. But, the trigger pulse generators i.e. trigger systems
has not been explained completely.
In this paper, a trigger system with high voltage isolation is
described in detail.
2/15
Conclusions:
1. The proposed trigger system is an open loop design.
2. The design of a simple pulse generator has been presented
with two different types of pulses:
Frequency: Variable
Pulse-1: 80 μs (Fixed)
up to 10kHz
Pulse-2: Variable up to 5 μs
Delay between Pulses: 10 μs (Fixed)
3. Optical isolation has been used.
4. High frequency inverter and induced voltage is used to isolate
driver Circuit.
5. The trigger system has been tested successfully with a Marx
Generator.
3/15
This work has been carried out at IEG, CSIR-CEERI, Pilani.
Trigger System: Provides trigger pulses to Semiconductor Switches to
turn ON or OFF.
High
Low
Trigger
System
4/15
=
Pulse
Generator
(With Controller)
+
Driver
Circuit
Trigger System & Isolation Issue:
No issue of Isolation……..
Trigger
Pulse
Reference of Trigger System
Common
Reference of Power Circuit
A Basic Switching Circuit
5/15
When & Why
Isolation Required ???
So, Isolation is required among
individual trigger pulses
(i.e. Pulses generated by Pulse Generator
and driver circuits both should be
isolated)
Q1
Floating or Series
Connected Devices
In Power Circuit
Q2
Trigger
System
Q3
Reference of Trigger System
6/15
A Basic Switching Circuit
Proposed Design: Two types of synchronized pulses have been
generated with high voltage isolation.
Pulse Generator Specifications:
Frequency of the pulses (fs)= up to 10 kHz
Pulse width of Pulse-1 = 80 µs (Fix)
Pulse width of Pulse-2 = up to5 µs
Delay = 10 µs (From trailing edge of Pulse-1)
Master Pulse to get
Frequency Variation
Max up to 10 kHz
Pulse-1:
80 µs
Delay:
10 µs
Pulse-2:
Variable up to 5 µs
7/15
Pulse Generator Design:
+15V
+15V
NE555
(Variable
Frequency)
+15V
+15V
4047BP
4047BP
4047BP
In Monostable
In Monostable
Master In Monostable
Pulse-1
Delay
Pulse-2
Mode
Mode
Mode
Frequency
+ve Edge
-ve Edge
-ve Edge
Triggered
Triggered
Triggered
Pulse
Generator
Variable
Resistors to
change Pulse
width &
Frequency
8/15
Pulse Generator Testing:
Conclusion-1:
It is an open loop design.
Pulse-1 (80µ s)
Pulse-2 (up to 5µ s)
9/15
Single Output Pulses
Output Pulses
Multiple Pulse Generation with Isolation:
To get a number of similar
pulses, a buffer IC ULN 2003 is used and since, pulses should be isolated to optical
transmitters are used to transmit the pulses.
Requirement is multiple
isolated pulses.
10/15
Variable Resistors to change
Pulse width of Pulse-2 &
Frequency of the pulses
Optical Transmitter
HFBR1521
ULN 2003
Isolated Driver Circuit:
Since pulses are transmitted via optical way so
driver circuit includes to sub-circuit-(i) Optical Receiver and (ii) Gate Driver
Circuit. Again, the driver circuit must be isolated.
Driver Circuit = Optical Receiver + Gate Driver Circuit
It must be isolated i.e.
its DC Supply must be isolated.
Regulator
Regulator
D
R
I
V
E
R
D
R
I
V
E
R
Inverter
(Operating Frequency = 20 kHz)
15
Induced Voltage in the Coil
11/15
Regulated DC Power Supply
Regulator
Optical Pulse
D
R
I
V
E
R
Isolated Gate Driver & Receiver Supply:
Regulator
Regulator
D
R
I
V
E
R
D
R
I
V
E
R
15
Regulator
D
R
I
V
E
R
Receiver: HFBR2521
Optical Pulse
Driver: IXDD414CI
Conclusion-3:
Optical isolation has been used.
+15 V for the driver
from the induced
voltage in the inductor
Conclusion-4:
High frequency inverter and induced voltage is used to isolate
driver Circuit.
12/15
Testing With Marx Generator:
R
D1
D2
D3
D4
D39
D40
X
C
C1
Q21
Gate
Pulse-2
Gate
Pulse-1
13/15
Q22
Gate
Pulse-2
Q1
Y
C20
C2
Q2
Gate
Pulse-1
Gate
Pulse-2
Q20
Gate
Pulse-1
Q40
RL
Top View of the PCB
Prototype Testing Arrangement
Conclusion-5
The trigger system has been tested successfully with Marx
Generator.
Output Pulse
Input dc Voltage
14/15
REFERENCES
D. Deb, J. Siambis, R. Symons, and G. Genovese, "Beam Switch Tube Modulator
Technology for Plasma Ion Implantation Broad Industrial Application", 9th IEEE International
Pulse Power Conf., 1993, pp. 333-336.
D. M. Goebel, R. J. Adler, D. F. Beals, and W. A. Reass, “Handbook of Plasma Immersion
Ion Implantation and Deposition”, Andre Anders, New York: 2000, pp. 472-477.
R. J. Adler, J. Scheuer, and W. Horne, "Thyratron modulators in plasma source ion
implantation", 10th IEEE International Pulse Power Conf., 1995, pp. 1243-1248.
Rahul Verma and K. S. Sangwan, “Development of a solid state versatile pulsar for high
voltage and high power applications”, IEEE Pulsed Power Conference, 2009, pp. 1312 - 1316.
H.J Ryoo, J.S Kim, G.H Rim, Danil Sytykh and Guennadi Gussev, “Development of 60kV
Pulse Power Generator Based on IGBT Stacks for Wide Application”, 27 th IEEE International
Power Modulator Symposium, 2006, pp. 511 - 514.