JPH04299062A - Driver for high voltage semiconductor switch - Google Patents

Abstract

PURPOSE:To obtain a driver for high voltage semiconductor switch having high noise resistance which causes no erroneous function nor failure even when the current rise rate of main circuit is quite high at the time of turn ON of a pulse laser power supply, for example. CONSTITUTION:Electrical energy for driving semiconductor elements is transmitted to a high voltage semiconductor switch comprising a plurality of semiconductor elements 24, 25 electrically connected in series with a power supply of ground potential through transformers 31, 31A employing race track type or rectangular cores 32, 37 mounting a primary winding 33 with secondary windings 34, 35 being disposed on a magnetic path in the longitudinal direction of the core.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage semiconductor switch used as a power source for an accelerator or a pulsed laser, and particularly to a drive device thereof.

0002

[Prior art] Figure 3 shows, for example, Mitsubishi Electric Technical Report Vol. 45, No. 6.
1 is a configuration diagram showing a conventional drive device for a high-voltage semiconductor switch disclosed in the No. High voltage semiconductor switches such as thyristor stacks 1 and 2 are connected in series with each other across a power supply (not shown). 3 is a control signal generator that generates a control signal for driving the thyristor; 4 is an uninterruptible power supply; 5 is a pulse generator connected to the output side of the control signal generator 3; 6 and 7 are uninterruptible power supplies 4 A high withstand voltage 1 is connected to the uninterruptible power supply 4 and is connected to the
The secondary conductors 8 and 9 are high voltage primary conductors connected to the pulse generator 5 and for passing the pulse current supplied from the pulse generator 5, and 10 is a toroidal core through which the high voltage primary conductor 6 passes. , 11 is a secondary winding wound around this toroidal core 10, 12 is a toroidal core through which the high voltage primary conductor 7 passes, 13 is a secondary winding wound around this toroidal core 12, 14 is a high A toroidal core through which the voltage-resistant primary conductor 8 passes, 15 a secondary winding wound around this toroidal core 14, 16 a toroidal core through which a high-voltage primary conductor 9 passes, and 17 wound around this toroidal core 16. 18 is a drive circuit for thyristor stack 1, 19 is a drive circuit for thyristor stack 2, 20
is provided in the drive circuit 18, and the secondary windings 13 and 17
A modulation gate amplifier 21 is provided in the drive circuit 18 and is connected to the output side of the modulation gate amplifier 20. A distribution gate transformer 22 is provided in the drive circuit 19 and connected to the secondary winding. Modulation type gate amplifiers 11 and 15 are connected, and 23 is a distribution gate transformer provided in the drive circuit 19 and connected to the output side of the modulation type gate amplifier.

The conventional drive device is constructed as described above. First, the high voltage primary conductor 6 is connected from the uninterruptible power supply 4 to the high voltage primary conductor 6.
and 7 are supplied with alternating current. When an alternating current flows through the high voltage primary conductor 7, magnetic flux is generated in the toroidal core 12 through which the high voltage primary conductor 7 passes due to the magnetic field created by the alternating current. As a result, an electromotive force is generated in the secondary winding 13 wound around the toroidal core 12. That is, the high voltage primary conductor 7, toroidal core 12, and secondary winding 13 constitute a transformer. Electrical energy is supplied from the uninterruptible power supply 4 to the drive circuit 18 at a high potential via this transformer. In addition, high voltage primary conductor 6, toroidal core 1
Similarly, the 0 and secondary windings 11 constitute a transformer. Electrical energy is supplied from the uninterruptible power supply 4 to the drive circuit 19 at a high potential via this transformer.

Next, a pulse current is supplied from the pulse generator 5 to the high voltage primary conductors 8 and 9 in response to a control signal sent from the control signal generator 3. The high voltage primary conductor 9, toroidal core 16, and secondary winding 17 constitute a transformer in the same way as the high voltage primary conductor 7, toroidal core 12, and secondary winding 13 described above. The pulse current supplied to the primary conductor 9 is transformed and supplied to the drive circuit 18. This pulse current is shaped by a modulating gate amplifier 20 provided in the drive circuit 18 and then distributed by a distribution gate transformer 21 to the four thyristors electrically connected in series in the thyristor stack 1. supplied to As a result, thyristor stack 1 is turned on. High voltage primary conductor 8, toroidal core 14, secondary winding 1
Since 5 also constitutes a transformer, the pulse current supplied to the high voltage primary conductor 8 is transformed and supplied to the drive circuit 19. This pulse current is shaped by a modulating gate amplifier 22 provided in the drive circuit 19 and then distributed by a distribution gate transformer 23 to the four thyristors electrically connected in series in the thyristor stack 2. supplied to As a result, the thyristor stack 2 is turned on.

In this way, when all the thyristor stacks constituting the high-voltage semiconductor switch are turned on at the same time and the high-voltage semiconductor switch becomes low impedance, the main circuit current i is conducted.

[0006]

[Problems to be Solved by the Invention] In conventional high-voltage semiconductor switches, as in DC power transmission and SVC, the current increase rate di/dt of the main circuit current i at turn-on is, for example, several tens of A/dt.
There is no problem when the current increase rate di/dt of the main circuit current i at turn-on is high, for example, several tens of A/μs, as in the case of a pulsed laser power supply, when the uninterruptible power supply 4 , pulse generator 5 and drive circuit 18,
There was a problem in that noise entered the 19, causing malfunction or failure of the high voltage semiconductor switch.

That is, in the conventional drive device, the high withstand voltage 1
The secondary conductors 6, 7, 8, 9 are largely routed along the thyristor stacks 1, 2. For this reason, a loop of the uninterruptible power supply 4 and the high voltage primary conductors 6 and 7 (this loop is connected to L1
The cross section of the pulse generator 5 and the loop of the high voltage primary conductors 8 and 9 (this loop is designated as L2) becomes larger.

On the other hand, a part of the magnetic flux created by the main circuit current i is
Since it passes through each section of the loops L1 and L2 described above, noise based on this is generated in the loops L1 and L2 as shown in the following equation.

[0009]

[Math 1]

[0010] However, e1 and e2 are the electromotive forces of noise generated in the loops L1 and L2, and φ1 and φ2 are the electromotive forces of the noise generated in the loops L1 and L2.
1, magnetic flux passing through L2, s1, s2 are loops L1, L
This is the cross-sectional area of 2.

As can be seen from equations (1) and (2), the magnitude of the noise, that is, the electromotive forces e1, e2, is determined by the current increase rate di/dt of the main circuit current i at turn-on and the loops L1, L2. It can be seen that it is proportional to the cross-sectional areas S1 and S2.

Therefore, even if noise is not a problem when the current increase rate di/dt is as low as several tens of A/μs, such as in DC power transmission or SVC, the current increase rate di/dt is low, such as in a pulsed laser power supply. When dt is large, such as several tens of A/μs, the nozzles also become large if the cross-sectional areas S1 and S2 of the loops L1 and L2 are large, resulting in problems such as malfunctions and failures of the high-voltage semiconductor switches.

[0013] The present invention was made in order to solve the above-mentioned problems, and the current increase rate di/dt of the main circuit current i at turn-on is several tens of A/μs, such as in a pulsed laser power supply. It is an object of the present invention to provide a drive device for a high-voltage semiconductor switch that has high noise resistance and does not cause malfunction or failure due to a nozzle even if the nozzle is large.

[0014]

[Means for Solving the Problems] A drive device for a high voltage semiconductor switch according to the present invention includes a power supply at ground potential, a racetrack-shaped or square core, and a core wound around the core and connected to the power supply. The transformer is provided with a primary winding and a secondary winding wound around the core and connected to each semiconductor element constituting the high voltage semiconductor switch.

[0015]

[Operation] In this invention, electrical energy is transmitted to a potential higher than the ground potential via a transformer, so
There is no need to route the primary winding at ground potential as large a route as in the past, and the cross-sectional area of the loop through which current flows through the primary winding can be reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the figure, 3, 4, 18, and 19 are the same as those described with respect to FIG. IGBTs 24 and 25 are a type of semiconductor element, and these IGBTs 24 and 25 are connected in series with each other across a power source (not shown). Reference numeral 26 is an E/O converter connected to the output side of the control signal generator 3 and converts an electrical signal into an optical signal, and includes light emitting diodes 27 and 28. 29
, 30 are optical fibers that connect the light emitting diodes 27, 28 to the drive circuits 18, 19, respectively. 31 is connected between the uninterruptible power supply 4 and the drive circuits 18, 19, and connects the uninterruptible power supply 4 at ground potential to the high potential. Drive circuit 18, 19
A transformer for supplying electrical energy to a racetrack core 32, the racetrack core 3
2 and connected to the uninterruptible power supply 4; secondary windings 34 and 35 wound around the racetrack core 32 and connected to the drive circuits 18 and 19, respectively; Further, an insulator 36 is disposed between the racetrack-shaped core 32 at ground potential and the secondary windings 34 and 35 at a high potential to maintain electrical insulation between them.

Next, the operation will be explained. First, alternating current is supplied from the uninterruptible power supply 4 to the primary winding 33 of the transformer 31 . When an alternating current flows through the primary winding 33, magnetic flux is generated in the racetrack-shaped core 32 due to the magnetic field created by this alternating current. As a result, the racetrack-shaped core 32
Since an electromotive force is generated in the secondary windings 34 and 35 wound around the drive circuits 18 and 19, which are electrically connected to the secondary windings 34 and 35, Electrical energy is supplied from a power source 4 via a transformer 31 .

Next, the control signal sent from the control signal generator 3 is converted into an optical signal by the light emitting diodes 27 and 28 provided in the E/O converter 26, and the optical fiber 2
9 and 30 to the drive circuits 18 and 19. The transmitted optical signal is converted back into an electrical signal by the drive circuits 18 and 19 using the electrical energy transmitted via the transformer 31, and is supplied to the IGBTs 24 and 25. As a result, IGBTs 24 and 25 are turned on.

In this way, when all the IGBTs constituting the high voltage semiconductor switch are turned on at the same time and the high voltage becomes a low impedance, the main circuit current i is conducted.

In this case, the cross-sectional area of the current loop of the uninterruptible power supply 4 and the primary winding 33 can be extremely small, so as is clear from the above equations (1) and (2), the conventional high voltage semiconductor Noise can be significantly suppressed compared to switches.

In the above embodiment, a racetrack core 32 is used as the core of the transformer 31, but a rectangular core 37 may be used as shown in FIG. In the embodiment of FIG. 2, each of the pair of longitudinal magnetic paths of the rectangular core 37 of the transformer 31A has a secondary winding (secondary windings 34 and 35 in one magnetic path, secondary windings 34 and 35 in the other magnetic path, Provide windings 34A and 35A, IGB
A circuit in which T24, 25 are connected in series and IGBT24A, 2
It is configured such that one transformer 31A can supply electrical energy to two parallel circuits of 5A connected in series.

[0022] The thickness of the amorphous magnetic material is 25 mm.
Since it is an extremely thin ribbon-like magnetic material on the order of μm, it can be easily formed into a racetrack-shaped core 32 or a rectangular core 37 with one side at least twice as long as the other side. It is suitable for the magnetic material of the core of transformers 31 and 31A.

As described above, according to the present invention, a power source at ground potential, a racetrack-shaped or square core,
A transformer having a primary winding wound around the core and connected to the power source, and a secondary winding wound around the core and connected to semiconductor elements constituting a high voltage semiconductor switch. , the cross-section of the current loop in the primary winding of the transformer can be made extremely small, resulting in
Since noise can be significantly suppressed, a high voltage semiconductor switch drive device with high noise resistance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the invention.

FIG. 3 is a configuration diagram showing a conventional drive device for a high voltage semiconductor switch.

[Explanation of symbols]

4 Uninterruptible power supply 18 Drive circuit 19 Drive circuit 24 IGBT 25 IGBT 26 E/O conversion device 29 Optical fiber 30 Optical fiber 31 Transformer 32 Racetrack-shaped core 33 Primary winding 34 Secondary winding 35 Secondary winding 37 Square core 18A drive circuit 19A Drive circuit 24A IGBT 25A IGBT 29A Optical fiber 30A optical fiber 31A Transformer 34A, 46 Secondary winding 35A, 46 Secondary winding

Claims (2)

[Claims] 1. A power source at ground potential, a racetrack or square core, a primary winding wound around the core and connected to the power source, and a high voltage semiconductor wound around the core. A transformer having a secondary winding connected to each semiconductor element constituting the switch, and driving each of the conductive elements at a high voltage with electrical energy transmitted from the ground potential to a high voltage. Features: High voltage semiconductor switch drive device. 2. The drive device for a high voltage semiconductor switch according to claim 1, wherein an amorphous magnetic material is applied to the core of the transformer.