RU37834U1 - DEVICE FOR CHECKING POWER DIODES AND THYRISTORS IN THE CONVERTER - Google Patents

Description

DEVICE FOR CHECKING POWER DIODES AND THYRISTORS

IN THE CONVERTER

The utility model relates to electrical engineering and can be used for diagnostics of power diodes and thyristors, as well as for the maintenance / maintenance of semiconductor converters.

A known device for monitoring the quality of power semiconductor devices containing a high-voltage power source, analog-to-digital converter, microprocessor, memory device, power source control device, test leads, resistors (Diode - Tester - SD. Technical description and operation manual. -M. : Energy, 2000. -34s.).

The peda of the known device for controlling the quality of power floors) of wire-plug devices is that it does not provide the possibility of diagnostics during a short circuit in the converter branch.

The closest in technical essence to the proposed device for checking power diodes and thyristors in the converter is a device selected for prototype testing of diodes and thyristors containing two switches, a milliammeter, three resistors, a voltmeter, a thread source, a signal lamp, a button, probes (Anikeev IP, Antropov BC Repair of electrical equipment of electric locomotives: a Textbook for SPTU. - M.: Transnort, 1989. -200p.).

The pedagogue of the known prototype is the need to dismantle the converter circuit when determining a through short circuit in one of several branches with a series connection of power diodes and thyristors.

20 Oh ....... ,,.

IPC: G01R31 / 02 IPC: O01K31 / 28

including short circuit in the semiconductor branch

converter without dismantling the latter.

To achieve the technical result, a device for checking power diodes and thyristors in a converter containing a power source, a milliammeter, two measuring resistors, a first voltmeter, a first measuring probe, is equipped with a protection unit, a second and third measuring probes, a second voltmeter, while the first and second the inputs of the power supply unit are connected to the positive and negative terminals of the power source, respectively, the first output of the power supply unit is connected to a common point of the cathode group of power elements a transistor converter, and the second output of the protection unit is connected to the input of a milliammeter, the output of which is connected to a common point of two measuring resistors connected in series, the input of the first measuring probe is connected to a common point of measuring resistors, the other terminals of the measuring resistors are connected to the inputs of the second and third measuring probes, and the outputs of all measuring probes are connected to the anodes of the tested power elements of the parallel branches of the cathode group of the semiconductor converter The first and second voltmeters are connected in parallel with two) um measuring resistors, respectively.

Comparative analysis with the prototype shows that the inventive device for checking power diodes and thyristors is characterized by the presence of new units: a protection unit, two additional measuring probes, a second voltmeter.

The drawing shows a diagram of a device for checking power diodes in the converter. The circuit of the device for checking power thyristors in the converter will be similar.

A device for checking power diodes and thyristors in the converter contains a power source 1, the positive and negative terminals of which are connected to the first and second inputs

protection unit 2 is appropriate, the first output of which is connected to a common point of the cathodic group power elements of the semiconductor converter, the second output is connected to the input of a milliammeter 3, the output of which is connected to a common point of the inputs of measuring resistors 4 and 5, connected in series, voltmeters 6 and 7, connected in parallel to the measuring resistors 4 and 5, respectively, the first measuring probe 8, the input of which is connected to the common point of the measuring resistors 4 and 5, and the output - with the anodes of the power elements of the cathode group converter transducers, additional test probes 9 and 10, the inputs of which are connected to the outputs of the measuring resistors 4 and 5, respectively, and the outputs are connected to the anodes of the tested power elements of the cathode group of the transducer.

To determine the branches with short-circuited series-connected power elements, the first output of the protection unit 2 is connected to the common point of the cathode group of the semiconductor converter, and the measuring probes 8, 9, 10 are connected to the anodes of the tested power elements of the cathode converter.

The resistance of the measuring resistors 4 and 5 is selected from the ratio

R Hist. ,

where is the resistance of the measuring resistors 4 and 5, Ohm;

IHCT. pit - current of a power source operating in a current source mode, mA;

UTO - threshold voltage of tested power semiconductor elements, V.

Moreover, if, for example, a short circuit of the power element VD2 occurs, then the current will flow as follows: from the power source 1 through the protection unit 2, the first output of the protection unit 2, the semiconductor element VD2, the probe 9, the measurement resistor 4, milliammeter 3, which will detect the presence of current in the circuit.

while the voltmeter 6 will record the presence of voltage on the measuring resistor 4.

With a short circuit VD4, the current will flow along the circuit: the first output of the protection unit 2, the semiconductor element VD4, the first measuring probe 8, milliammeter 3, which will detect the presence of current in the ash. In this case, voltmeters 6 and 7 have zero readings.

In the event of a short circuit of the power element VD6, the current will flow as follows: from the power source 1 through the protection unit 2, the first output of the protection unit 2, the semiconductor element VD6, the measuring probe 10, the measuring resistor 5, milliammeter 3, which will detect the presence of current in the circuit. In this case, the voltmeter 7 will detect the presence of voltage on the measuring resistor 5.

If there is no short circuit of power elements in the floor-to-wire converter, then the readings of voltmeters 4 and 5 and milliammeter 3 will be equal to zero. The protection unit 2 provides the inclusion of a power source 1 operating in the current source mode when a certain voltage level is reached.

The protection unit 2 can be raised in the form of a device to protect the DC source from overload (USSR Author's Certificate No. 1261039. Bull. No. 36. -30.09.86).

Claims (1)

A device for checking power diodes and thyristors in a converter containing a power source, a milliammeter, two measuring resistors, a first voltmeter, a first measuring probe, characterized in that it is equipped with a protection unit, a second and third measuring probes, a second voltmeter, while the first and second the inputs of the protection unit are connected to the positive and negative terminals of the power source, respectively, the first output of the protection unit is connected to a common point of the cathode group of power elements of the semiconductor converter The second output of the protection unit is connected to the input of a milliammeter, the output of which is connected to a common point of two measuring resistors connected in series, the input of the first measuring probe is connected to a common point of measuring resistors, other outputs of the measuring resistors are connected to the inputs of the second and third measuring probes and the outputs of all measuring probes are connected to the anodes of the tested power elements of the parallel branches of the cathode group of the semiconductor converter, the first and second voltmeters are connected in parallel to two measuring resistors respectively.