Overview

The GUI interface was designed to reduce the computation time of the snabber RC circuit when designing a thyristor / diode in six-pulse bridge connection (B6).

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The calculation sequence is determined by 5 steps.

1. Entering the parameters of the transformer, grid, busbar

2. Calculation of the maximum line voltage, the desired overvoltage class is set, the phase inductance is calculated, the di / dt is calculated. With a known grid inductance, it is possible to set it manually, then the di / dt value will be recalculated

3. the dynamic parameters of the semiconductor device are set either manually or can be selected from the list. The required capacity is calculated for the snabber RC circuit

4. Calculation of resistance and power of resistor snabber RC circuit

5. Calculation of the expected overvoltage according to the designed parameters. There are 3 options for assessing overvoltage:

• according to the model to which the data from the GUI interface is transferred, the model runs in the background, the simulation result is transferred back to the GUI interface

• solution of the differential equation using Matlab tools, upon completion of the calculation, the plot is displayed

• simplified formula rough estimate

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By clicking the Report button, a report is generated in the Word document format, which displays the calculation results with explanations, as well as all the initial and intermediate calculation data.

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The calculation results are:

• capacitance of the RC-circuit capacitor,

• the resistance of the RC-circuit resistor and the power released in it,

• expected value du / dt on a semiconductor device (thyristor, diode)

• the expected magnitude of overvoltages for the selected RC circuit,

• an automatically generated report in Word with initial, intermediate parameters and results.