ABB Non-Isolated DC-DC Converter with IGBT and Diode User Manual

ABB Non-Isolated DC-DC Converter with IGBT and Diode

INTRODUCTION

SEMIS is a web-based semiconductor simulation tool providing a thermal calculation of the semiconductor losses for common converter circuits. The simulation simplifies significantly the selection of the switching de-vice and enables the optimal selection of semiconductors for further investigations. The SEMIS Simulation Tool is a user-friendly online application found on ABB Semiconductors website www.abb.com/semi-conductors/semis SEMIS users select from a substantial selection of topologies. By assigning the circuit parameters and selecting the desired switching device, multiple ABB products can be simulated at the same time. Once a simulation is run, SEMIS returns compre-hensive results on semiconductor losses as well as on the electrical parameters in the input and output of the circuit. The re-sults are shown in both graphical (waveforms) and numerical (tables) way. The SEMIS tool is based on the PLECS simulation software. PLECS users can download our product models in the XML file format from the ABB Semiconductors website and use them for their own simulations. For more specific topologies ABB offers customized converter simulations for non-standard topologies with PLECS simulation software on a project basis.

COPYRIGHTS

• All rights to copyrights, registered trademarks, and trademarks reside with their respective owners.
• Copyright © 2019 ABB Power Grids Switzerland Ltd.
• All rights reserved.
• Release: December 2019
• Document number: 5SYA 2132

NON ISOLATED DC-DC CONVERTER MODELS

Non-Isolated DC-DC converters are widely used in battery charging and DC motor drive applications. In general, the output of an AC-DC converter is a fluctuating DC voltage due to the changes in the line voltage magnitude. DC-DC converters are used to convert the unregulated DC input into a controlled DC output at the desired volt-age level. These converters can be categorized as Non-Isolated and Isolated types. The difference lies in the fact that isolated converters use high-frequency transformers. This manual discusses only the Non-Isolated type of converters.

ABB offers the following Non-Isolated DC-DC converters for thermal analysis simulation in non-Isolated DC-DC converters:

• Non-Isolated Buck converter (Uout < Uin)
• Non-Isolated Boost converter (Uout > Uin)
• Non-Isolated Buck-Boost converter (Uout <> Uin)

Furthermore, ABB offers the following Isolated DC-DC converters for thermal analysis simulation

• Isolated Flyback converter (Derived from Buck-Boost converter)
• Isolated Forward converter (Derived from step-down converter)
• Isolated Push-Pull converter
• Isolated Half-Bridge converter
• Isolated Full-Bridge converter

OVERVIEW

SIMULATION SETTINGS

Circuit parameters

The user can choose between the 3 types of converters here. For the case when the output voltage required is less than the input voltage, the buck converter can be chosen. If the output must be stepped up, the Boost converter can be chosen. To do either step-up or step-down operation, the buck-boost converter can be chosen.

Figure 2 Converter settings input blocks

• CONVERTER TYPE Converter is operated as Buck, Boost or Selection Buck-Boost mode
• INPUT DC VOLTAGE Input DC Voltage of the converter Range 10 .. 1500 V AMBIENT TEMPERATURE Ambient Temperature Range -25 .. 90 ºC
• OUTPUT POWER Power demand of load Range 1 .. 150 kW
• OUTPUT DC VOLTAGE The constant DC output voltage Range 30 .. 1000V on load
• SWITCHING FREQUENCY Frequency at which the IGBT Range 200 .. 10000 Hz is turned ON/OFF

IGBT Settings

Figure 3 Thermal settings and IGBT selection

• Heat Sink Thermal Resistance Range 0.0001 .. 0.5 K/W Definition of thermal resistance of the cooling system applied.

Remark

The value entered is attributed to each individual switch shown in the electrical configuration schematic of the IGBT module datasheet. Therefore, if the user selects a dual switch module, the Rth should be multiplied with a factor of 2 to differentiate from the single switch case, if the same heatsink would be used in both cases. The selected Rth is also accounted for the diode position for which same consideration applies for its electrical configuration.

• IGBT module type Select housing type of IGBT for filtering Selection
• IGBT selection Select voltage class of IGBT for filtering Selection
• Module configuration Select topology of IGBT module for filtering Selection

Matching IGBTs

Once the previous IGBT properties are selected the matching IGBT options appear. By clicking on the product code name the user may access the datasheet from ABB website.

• Users can select the desired IGBTs and Diodes product names for simulation.
• Up to 4 elements can be selected simultaneously and simulated. If one or more elements produce results exceeding the safe operating area (SOA) then they will return no results. In this case, the user should run the simulation again with changed
• parameters and/or product selection to enable results within SOA operating conditions.

Matching Diodes

Once the IGBT’s are selected, the user can choose between Chopper diodes or FRDs based on the choice in the MODULE CONFIGURATION of section 3.2.1. Chopper diodes are populated in this dropdown in addition to the FRDs if Chopper is chosen in MODULE CONFIGURATION. After choosing the DIODE TYPE, the matching Di-odes can be selected according to the voltage and current ratings. By clicking on the product code name the user may access the datasheet from the ABB website.

Selection of articles / Start simulation

• To simulate one or more articles, select from the list by activating the checkbox
• Simulate Starts the simulation
• The progress of the simulation is shown with the number of calculated Jacobian.
• Abort Stops the simulation; No results generated
• Hold results To compare multiple simulations, results can be held for later viewing. By selecting the button, the result are hold after the simulation has finalized for later comparison with succeeding simulations

SIMULATION RESULTS

• The simulation results are displayed in two different ways for all selected articles simulated.
• To hide curves of selected articles, unselect in the table “Results History”
• Graphical results – Waveforms Visual analysis of waveforms for fast and efficient detection of most significant sources
• Numerical / Tabular results Numeric indication of all simulations values for direct comparison

Graphical Output – Waveforms

When the simulation finishes the semiconductor and DC side waveforms are shown as follows:

Control

• For an indication of values within the graph, a cursor can be activated to show curve values in a table.
• Sections of graphs can be zoomed in by click, move and release mouse button for more details

Parameters values indication

Tabular indication of graphical waveforms values according to the cursor position selected. Values are indicated for each parameter Color of the waveform is indicated. The third column shows the differ-ence between the two cursors per parameter.

Remark
The numerical values of Voltage/Current at the position of respective cursors are shown in the Table. The numer-ical values of IGBT current/Diode Current along with their Switching loss, Conduction loss and Junction tempera-tures at the position of respective cursors are shown in the Table.

Numerical / Tabular results

The following parameters are given in a tabular format in multiple sections. All calculations and simulation results are based on datasheet typical values. All types of semiconductor losses are calculated according to the PLEXIM PLECS software principle through the reference to the lookup table and linear interpolation of the actual device current, voltage and junction tempera-ture. The indicated elements (numbered) in the table correspond to the different semiconductor devices in the DC-DC converters as shown in 2. As converter losses, the aggregated losses in all devices are accounted for. The buck and boost converters have 2 devices each (an IGBT and a diode), so the losses and other parameters for IGBT2 and Diode2 are shown as zero. These values will be non-zero in the case of the Buck-Boost converter as it has 2 IGBTS and 2 Diodes.

Figure 10 Device Losses & Temperatures

• Switching Loss Single IGBT or Diode Losses during turn on and turn off events (dynamic)
• Conduction loss Single IGBT or Diode Losses during on state (static)
• Combined losses Sum of single IGBT or Diode switching and conduction loss.
• Converter losses Sum of all IGBT and Diode losses % Losses Defined as the (%) ratio of calculated combined converter losses with respect to the total output power and losses i.e., total apparent power flow.
• Junction Temperature Avg Junction temperature average during the simulation period
• Junction Temperature Max Maximum junction temperature during the simulation period
• Junction Temperature BLS Junction temperature at the time point just before the switching, after which the maximum junction temperature is achieved

DC-DC parameters

• Input DC power Active power supplied by the source including the thermal losses
• Output DC power Load power set by the user as explained in section 3.1.1.
• Input DC voltage DC voltage supplied at the input of the converter (Usually the output of a rectifier)
• Output DC voltage DC voltage output set by the user as explained in section 3.1.1.
• DC Current DC current is drawn by the load at the power set by the user.
• Duty ratio Duty ratio is calculated and displayed as per section 6.

General parameters

• Switching Freq. According to the definition
• Ambient Temp. According to the definition

ALERTS & FEATURES

The system verifies results and generated warning messages in case of limits are violated.

• Parameter Junction temperature
• Verification If the maximum junction temperature of IGBT and/or diode is above its maximum junction temperature limit, the alert message is displayed
• Warning message IGBT temperature out of the safe operating area
• Parameter DC Blocking voltage
• Verification If the voltage rating of the IGBT and/or diode is less than the DC blocking voltage, the alert message is displayed
• Warning message For the selected device voltage rating, the operating range of the device is dis-played Parameter Duty ratio
• Verification Range of Duty ratio is 0 to 1. If the duty ratio is out of these limits and an alert message is displayed
• Warning message(s) Output voltage should be less than the input voltage for Buck operation
• Output voltage should be greater than the input voltage for Boost operation

APPLIED CALCULATIONS

Input Parameter Definitions

• VDC Input DC voltage
• VOUT Output DC voltage

Duty ratio of the converter

The following calculations have been used in the model to calculate the duty ratio

• For Buck converter
• For Boost converter
• For Buck-Boost converter

Load side

The resistive load is formulated based on the following equations for each of the converters

• POUT DC power / real power at the load
• D Duty cycle as per section 6.2
• Rout Resistive load of the converter
• For Buck converter
• For Boost converter
• For Buck-Boost converter

VALIDATION OF PLECS RESULTS WITH PSCAD

To ensure supplied simulation results are reliable, each of the Non-Isolated DC-DC converter model is validated with another simulation platform or compared to real measurement data. The circuit topology is reconstructed in PSCAD to validate the results obtained from the SEMIS web simulation tool. The objective of the work is to develop an open-loop, Buck, Boost and Buck-Boost converter models with loss and temperature estimation in PSCAD and to validate the steady-state results obtained through SEMIS-22 web simulation model using pulse-width modulation. The IGBT and Diode XML data which was created from the device datasheets for SEMIS simulations is modified to individual .txt files for switch turn-on energy (Eon), switch turn-off energy (Eoff), diode reverse recovery en-ergy (Erec), on-state voltage drop of IGBT (Vt), and on state voltage drop of diode (Vd) at different temperatures, to make the data readable in PSCAD. The PSCAD and SEMIS circuit models are made as identical as possible to prevent any errors in validation due to the dissimilarities. Junction to Case and Case to Heat sink thermal resistances for the IGBT and Diode have been captured from the device datasheet while the Heat sink to ambient thermal resistance Rth(h-a) is assumed as 2K/kW with different ambient temperatures. Five cases are simulated in PSCAD and SEMIS by varying different parameters like DC Voltage, Switching Fre-quency, Load Power, Heat Sink, etc. with the electrical parameters presented in the tables below for comparison.

Results analysis according settings

Results analysis according settings

Results analysis according settings

USER MANUAL REVISION HISTORY

SIMULATION SOFTWARE RELEASE HISTORY

Contact

ABB Power Grids Switzerland Ltd.Semiconductors Fabrikstrasse 3 5600 Lenzburg, Switzerland Phone: +41 58 586 1419 Fax: +41 58 586 1306 E-Mail: abbsem@ch.abb.com abb.com/semiconductors

Note
We reserve the right to make technical changes or modify the contents of this document without prior notice. With regard to purchase orders, the agreed particulars shall prevail. ABB does not accept any responsibility whatsoever for potential errors or possible lack of information in this document. We reserve all rights in this document in the subject matter and illustrations contained therein. Any reproduction- in whole or in parts- is forbidden without ABB’s prior written consent.

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