JP4854007B2 - Semiconductor power conversion device and test method thereof - Google Patents

Description

  The present invention relates to a semiconductor power conversion device and a test method thereof, and more particularly to a semiconductor power conversion device and a test method thereof capable of appropriately performing an impulse test.

  In the semiconductor power converter connected to the power system, the applied voltage at the time of the impulse test is determined according to the voltage of the connected power system, and by applying this impulse voltage, the insulation design of the semiconductor power converter is designed. Check the soundness and confirm that no malfunction occurs in the semiconductor power converter due to the impulse voltage. This outline is described in, for example, JEC2410 “Semiconductor Power Converter”.

  Here, as a method for determining whether or not a malfunction occurs in the semiconductor power conversion device by the impulse test, the value of the gate current induced in the gate circuit by the application of the impulse voltage is the gate current at which the semiconductor switching element does not operate. It is common to judge whether it is smaller or larger than the value (non-trigger current level).

  Usually, in order to measure the gate current of the semiconductor switching element constituting the semiconductor power conversion device, the voltage across the impedance inserted in series in the gate circuit is measured. A semiconductor power conversion device that partially incorporates the gate current measurement unit has been proposed (see, for example, Patent Document 1).

Therefore, in order to measure the current value induced during the impulse test, when the impulse voltage is applied to the semiconductor switching element of the semiconductor power converter by the impulse test device, the voltage across the impedance inserted in series in the gate circuit Can be measured.
JP2003-143833 (page 4, FIG. 1)

  Although the gate current induced at the time of the impulse test can be measured using the circuit shown in Patent Document 1, it is necessary to provide an external measuring device in order to confirm a minute non-trigger current. In the case of a semiconductor power conversion device used at a high voltage, this measuring instrument has a dielectric strength that can sufficiently withstand the impulse voltage and a small non-trigger current (several milliamps) of the semiconductor element under the environment where the impulse voltage is applied. It is necessary to have high accuracy and high noise resistance.

  However, measuring instruments that satisfy these requirements are extremely complex and expensive due to the special characteristics of the required specifications, and can be used in large-scale power facilities. However, there is a problem when applied to ordinary facilities. was there.

  The present invention has been made in view of the above, and an object of the present invention is to provide a semiconductor power conversion device and a test method thereof that can easily measure a current flowing in a gate circuit of a semiconductor element in an impulse test.

  In order to achieve the above object, a semiconductor power conversion device and a test method thereof according to a first invention of the present invention include a plurality of conversion arms constituting a power converter, and a semiconductor switching element constituting the conversion arm, A semiconductor power conversion device comprising a gate circuit for supplying a gate pulse to the gate electrode of each of the semiconductor switching elements, wherein one or more are provided between the output of the gate circuit and the gate electrode of the semiconductor switching element. When light emitting elements connected in series are attached and an impulse voltage is applied to both ends of the conversion arm, the amount of gate current applied is converted into an optical signal by the light emitting element, and the optical signal is connected by an optical fiber connected to the light emitting element. The impulse test is performed by measuring the gate current through a light quantity measuring device provided outside. It is characterized in that.

The semiconductor power conversion device and the test method thereof according to the second invention of the present invention include a plurality of conversion arms constituting a power converter, a semiconductor switching element constituting the conversion arm,
In a semiconductor power conversion device comprising a gate circuit that supplies a gate pulse to the gate electrode of each semiconductor switching element and has one or a plurality of light emitting elements connected in series at the output part thereof, both ends of the conversion arm When an impulse voltage is applied, the gate current is converted into an optical signal by the light emitting element, and the optical signal is guided to an external light amount measuring device by an optical fiber connected to the light emitting element. It is characterized in that an impulse test is performed by measuring.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor power converter device which can measure easily the electric current which flows into the gate circuit of a semiconductor element in an impulse test, and its test method can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 is a block configuration diagram of a semiconductor power conversion device according to a first embodiment of the present invention.

  The semiconductor power conversion device 1 is a device for converting direct current into alternating current, for example. This semiconductor power conversion device 1 has a power conversion unit and a control unit for controlling the power conversion unit, and one of the conversion arms of the power conversion unit is a conversion arm 2. The conversion arm 2 has a semiconductor switching element 3. The semiconductor switching element in the conversion arm 2 may be a plurality of elements connected in series, connected in parallel, or a combination of these. In that case, the semiconductor switching element 3 represents one of a plurality of semiconductor switching elements. The semiconductor switching element 3 is a semiconductor switching element having a gate electrode, and corresponds to, for example, a thyristor, a transistor, a GTO thyristor, and an IGBT.

  The gate pulse generator 4 that constitutes a part of the control unit described above generates a reference pulse to be applied to the gate of the semiconductor switching element 3. This reference pulse is directly supplied to the gate of the semiconductor switching element 3 through the waveform adjustment circuit 51 and the filter circuit 52 in the gate circuit 5 and controls the on / off operation of the semiconductor switching element 3 during normal operation.

  When performing the impulse test, the light emitting element 6 is inserted in series between the output of the gate circuit 5 and the gate of the semiconductor switching element 3 as shown in the figure. Although the number of the light emitting elements 6 may be one, a plurality of light emitting elements may be connected in series as illustrated.

  In the impulse test, as shown in the figure, a predetermined voltage pulse is applied to both ends of the conversion arm 2 by the impulse test device 7 from the outside of the semiconductor power conversion device 1, and the gate current of the semiconductor switching element 3 at that time is checked. . Since this gate current is a current flowing through the light emitting element 6, the light generated by the light emitting element 6 is led out of the semiconductor power conversion device 1 by the optical fiber 8 connected to the light emitting element 6. When the light emitting element 6 is n series connection bodies, it is set as the structure which gathers this light to one with the optical fiber branched into n pieces.

  The light guided by the optical fiber 8 is converted into an electric signal by the light quantity measuring device 9 and observed by the oscilloscope 10. Here, the light quantity measuring device 9 includes a DC power source 91, a resistor 92, and a photodiode 93 of a light receiving unit.

  With the configuration described above, it is possible to measure the gate current induced during the impulse test. According to this method, since only the small light emitting element 6 requires high breakdown voltage, a relatively large optical signal converter having, for example, power supply portions at both ends of the waveform adjustment circuit 51 as in the prior art. Compared to the method of attaching the battery, not only is the structure simple, but it is also less susceptible to noise.

  Before performing the impulse test, a non-triggered current can be calibrated by applying a simulated gate current with the light emitting element 6 inserted and measuring the output of the light quantity measuring device 9 for this normal gate current. It becomes. The amount of light generated by the light emitting element 6 can be adjusted by adjusting the number of light emitting elements 6 in series.

  FIG. 2 is a block diagram of a semiconductor power conversion device according to the second embodiment of the present invention.

  About each part of this Example 2, the same part as each part of the block block diagram of the semiconductor power converter device which concerns on Example 1 of FIG. 1 is shown with the same code | symbol, and the description is abbreviate | omitted. The second embodiment is different from the first embodiment in that the light emitting element 6A is built in the output portion of the gate circuit 5 in place of the light emitting element 6 added from the outside.

  In Example 1, the light emitting element 6 is added only during the impulse test of the target gate circuit, and is removed during normal operation. On the other hand, in this embodiment, the light emitting element 6A is always built in the gate circuit 5, and a gate pulse is given through the light emitting element 6A even during normal operation.

  Therefore, if the application is such that the gate voltage drop due to the light emitting element 6A is not a problem, the gate current can be measured simply by attaching the optical fiber 8 to the light emitting element 6A during the impulse test.

  As described above, in the present embodiment, since the gate circuit 5 is standardized for impulse testing, not only the design of the semiconductor power converter 1 is facilitated, but also the impulse testing can be performed more easily. It becomes possible.

  FIG. 3 is a block diagram of a semiconductor power conversion device according to Embodiment 3 of the present invention.

  About each part of this Example 3, the same part as each part of the block block diagram of the semiconductor power converter device which concerns on Example 2 of FIG. 2 is shown with the same code | symbol, and the description is abbreviate | omitted. The third embodiment is different from the second embodiment in that a short circuit 53 is provided in parallel with the light emitting element 6A in the gate circuit 5.

  As described in the second embodiment, if the gate voltage drop due to the light emitting element 6A is not a problem, a gate pulse may be applied through the light emitting element 6A even during normal operation. This embodiment is effective when it is necessary to exclude the gate voltage drop due to the light emitting element 6A during operation. As a specific method of the impulse test, the impulse test may be performed by removing the short circuit 53 of the gate circuit to be tested.

  FIG. 4 is a block diagram of a semiconductor power conversion device according to Embodiment 4 of the present invention.

  In each part of the fourth embodiment, the same parts as those in the block configuration diagram of the semiconductor power conversion device according to the first embodiment of FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. The fourth embodiment is different from the first embodiment in that a diode 54 and a short circuit 55 are provided at the output portion in the gate circuit 5, and the gate circuit 5 receives a gate pulse through a parallel circuit of the diode 54 and the short circuit 55. It is the point which comprised so that it might supply.

  In a gate circuit of a high voltage semiconductor power conversion device, a diode 54 may be provided in series in order to prevent the gate current from flowing backward due to the influence of noise or the like. Therefore, when the impulse test is performed, if the diode 54 of the gate circuit to be tested is short-circuited by the short circuit 55, the state equivalent to the case of the first embodiment at the time of the impulse test, that is, the additional impedance of the gate is the light emitting element. 6 impedance. On the other hand, the gate circuit that does not perform the impulse test removes the short circuit 55 and makes use of the backflow prevention function of the diode 54. Here, if the impedance of the light emitting element 6 and the impedance of the diode 54 are equal, the impedance of the gate circuit during the impulse test can be matched with the impedance during normal operation for all the gate circuits. Therefore, since the value of the gate current induced when the impulse voltage is applied is theoretically equal to the gate current in the actual operation state, the measurement accuracy can be further improved.

  In the above, the impedance corresponds to a forward voltage drop. Therefore, for example, when three backflow preventing diodes 54 are connected in series and the impedance per one light emitting element 6 is equal, the impedance becomes substantially equal if three light emitting elements 6 are also connected in series. .

BRIEF DESCRIPTION OF THE DRAWINGS The block block diagram of the semiconductor power converter device which concerns on Example 1 of this invention. The block block diagram of the semiconductor power converter device which concerns on Example 2 of this invention. The block block diagram of the semiconductor power converter device which concerns on Example 3 of this invention. The block block diagram of the semiconductor power converter device which concerns on Example 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor power converter 2 Conversion arm 3 Semiconductor switching element 4 Gate pulse generation circuit 5 Gate circuit 51 Waveform adjustment circuit 52 Filter circuit 53 Short circuit 54 Diode 55 Short circuit

6 Light emitting element 7 Impulse test device 8 Optical fiber 9 Light quantity measuring device 91 DC power source 92 Resistance 93 Photodiode

10 Oscilloscope

Claims (7)

A plurality of conversion arms constituting a power converter;
A semiconductor switching element constituting the conversion arm;
A gate circuit for supplying a gate pulse to the gate electrode of each of the semiconductor switching elements,
When performing an impulse test by applying an impulse voltage to both ends of the conversion arm,
One or more light emitting elements connected in series are attached between the output of the gate circuit and the gate electrode of the semiconductor switching element,
A semiconductor power conversion device, wherein the amount of energization of the gate current during the impulse test is converted into an optical signal and output. A plurality of conversion arms constituting a power converter;
A semiconductor switching element constituting the conversion arm;
A gate circuit for supplying a gate pulse to the gate electrode of each of the semiconductor switching elements,
The gate circuit has one or a plurality of light emitting elements connected in series at an output portion thereof,
When performing an impulse test by applying an impulse voltage to both ends of the conversion arm,
A semiconductor power converter characterized in that the light emitting element converts an energization amount of a gate current into an optical signal and outputs it. Providing a first short circuit in parallel with the light emitting element;
Among the gate circuits, the gate circuit that does not perform the impulse test is:
The semiconductor power conversion device according to claim 2, wherein the light emitting element is short-circuited by the first short circuit. The gate circuit has one or a plurality of diodes connected in series to the output portion thereof and a second short circuit provided in parallel with the diode,
Among the gate circuits, the gate circuit that does not perform the impulse test is:
The semiconductor power conversion device according to claim 1, wherein the diode is short-circuited by the second short circuit.   The semiconductor power conversion device according to claim 4, wherein an impedance of the light emitting element is substantially equal to an impedance of the diode. A plurality of conversion arms constituting a power converter;
A semiconductor switching element constituting the conversion arm;
In a semiconductor power converter comprising a gate circuit for supplying a gate pulse to the gate electrode of each semiconductor switching element,
One or more light emitting elements connected in series are attached between the output of the gate circuit and the gate electrode of the semiconductor switching element,
When an impulse voltage is applied to both ends of the conversion arm, the amount of gate current applied is converted into an optical signal by the light emitting element,
A method for testing a semiconductor power conversion device during an impulse test, wherein the gate current is measured by guiding the optical signal to an external light amount measuring device provided by an optical fiber connected to the light emitting element. A plurality of conversion arms constituting a power converter;
A semiconductor switching element constituting the conversion arm;
In a semiconductor power conversion device comprising a gate circuit that supplies a gate pulse to the gate electrode of each of the semiconductor switching elements and has one or more light emitting elements connected in series at the output part thereof,
When an impulse voltage is applied to both ends of the conversion arm, the amount of gate current applied is converted into an optical signal by the light emitting element,
A method for testing a semiconductor power conversion device during an impulse test, wherein the gate current is measured by guiding the optical signal to an external light amount measuring device provided by an optical fiber connected to the light emitting element.

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