HITACHI SEMIS Simulation Tool Thyristor Based EV Charging Converters User Manual

HITACHI SEMIS Simulation Tool Thyristor Based EV Charging Converters

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 device 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/semiconductors/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 comprehensive results on semiconductor losses as well as on the electrical parameters in the input and output of the circuit. The results 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.
© 2020 Hitachi ABB Power Grids. All rights reserved.
Release: November 2020
Document number: 5SYA 2136

THYRISTOR BASED EV CHARGING CONVERTERS

Electric vehicle chargers are typical AC-DC converters based on diodes, IGBTs or thyristors at the first stage and DC-DC converters at the second stage to suit the battery charging voltage and to improve the power quality. The first stage of the converters used in this model is Thyristor based:

– 3 phase 12 pulse series-connected thyristor rectifier
– 3 phase 12 pulse parallel-connected thyristor rectifier
The DC-DC converters used are non-isolated ones:
– Buck converter
– Boost converter
ABB offers the following Non-isolated DC-DC converters for thermal analysis simulation in Thyristor based EV charging converters
– 3 phase 12 pulse series-connected thyristor rectifier + Buck converter: Domestic low voltage three phase of 415V is stepped down to values as low as 60V
– 3 phase 12 pulse parallel-connected thyristor rectifier + Boost converter: High power applications like E-Bus charging infrastructure.

OVERVIEW

IGBT, Thyristor selection         Results tables

SIMULATION SETTINGS

Rectifier settings

The user can choose between the 2 types of rectifiers that are mentioned in section 1. The output of the rectifier can be set here.

**Figure 2 Rectifier settings input blocks**

Converter settings

The user can choose between the 2 types of converters here. The user shall select the buck converter for stepping down the output voltage of the rectifier and boost converter for stepping up the output voltage. These converters are modeled to operate in Continuous Conduction Mode (CCM), one shall change the user inputs as shown in Figure 3 Converter settings input blocks to operate the converters in CCM.

Figure 3 Converter settings input blocks

on
SWITCHING FREQUENCY| Frequency at which the IGBT Hz is turned ON/OFF| Range 200 .. 5000

IGBT settings

Figure 4 Thermal settings and device selection

Heat Sink Thermal Resistance| Definition of thermal resistance of the cooling system applied.| R ange 0.0001 .. 0.5 K/W
---|---|---
Remark:| The value entered is attributed to each individual switch is shown in the electrical configuration schematic of the IGBT module datasheet. Therefore, if a 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
Thyristor selection| Select voltage class of Thyristor 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 option appears. By clicking on the product code name the user may access the datasheet from the ABB website.

Figure 5 Matching IGBTs for selection

Users can select the desired IGBTs 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 Thyristors

Once the IGBT’s are selected, the user can do the Rectifier Thyristors selection for the front end rectifier based on the voltage rating chosen. By clicking on the product code name the user may access the datasheet from the ABB website.

Figure 6 Matching Rectifier Thyristors for selection

Selection of articles / Start simulation

To simulate one or more articles, select from the list by activating the checkbox The progress of the simulation is shown with the number of calculated Jacobians.

viewing By selecting the button, results are held 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| Visual analysis of waveforms for fast and efficient detection of most significant sources
---|---
Numerical results| Numeric indication of all simulations values for direct comparison

Graphical Output – Waveforms

When the simulation finishes the semiconductor and DC side waveforms are appearing 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

| Hide selectively waveforms of products
---|---
| Rest zoom to full view
| Activate cursors and to show parameter values table according to the cursor position
| Zoom selectable rectangle
| Zoom horizontal or vertical band

Parameters values indication

Tabular indication of graphical waveforms values according to the cursor position selected. Values are indicated for each parameter. The third column shows the difference between the two cursors per parameter.

Remark:

The numerical values of Phase Voltage/Current at the position of respective cursors are shown in the Table.
The numerical values of IGBT/Diode/Thyristor current along with their Switching loss, Conduction loss and Junction temperatures 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 temperature.
The losses per thyristor are tabulated. The rectifier losses are arrived at by multiplying the per rectifier device losses by 12 for both kinds of rectifiers. The cumulative losses for the topology are calculated as the sum of the losses of the rectifier and the converter.

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 BLS

AC-DC parameters

ℎ_ ∗ (1 )
Phase Voltage (RMS)| AC voltage per phase at the source
Phase current (RMS)| AC current drawn at the source by the load
Input Frequency (Hz)| Frequency of the source voltage

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

ALERTS & FEATURES

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

the last switch is above its maximum junction temperature limit, an alert message is displayed
Warning message| IGBT/Diode 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 displayed
Parameter| Output DC voltage of the rectifier (Vdc)
Verification| If the output dc voltage of the rectifier is above 2.70VLLcos(α) and 1.35VLL cos(α) for series-connected rectifier and parallel-connected rectifier respectively.
Warning message| For the given VLL, Vdc must be reduced (or) for the given Vdc, VLL must be increased
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

Firing angle (α) of the converter

IDC is the load current drawn by the DC-DC converter:

The firing angle α is based on the IDC according

A) 3 phase thyristor series-connected:

B) 3 phase thyristor parallel-connected:

Output Capacitance of the rectifier

The output capacitance is designed based on the ripple percentage with reference to the peak voltage (VDC). The ripple factor is calculated as a product of ripple percentage which is considered as 1 %.

Duty ratio of the converter

The output of the rectifiers serves as input to the DC-DC converters. The following calculations have been used in the model to calculate the duty ratio:

Buck converter:

Boost converter:

Load side

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

Buck converter:

Boost converter:

Inductance design for CCM

The inductance design for Continuous Conduction Mode (CCM) of the converter is according

Buck converter:

Boost converter:

Output smoothing C

The output capacitance for smoothing the is according

Buck converter:

Boost converter:

VALIDATION OF PLECS RESULTS WITH PSCAD

To ensure supplied simulation results are reliable, each of the Thyristor rectifier models in combination with either buck or boost on the secondary is validated with another simulation platform.
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 a 12 pulse series connected thy bridge + buck, 12 pulse series connected thy bridge + boost, 12 pulse parallel connected thy bridge + buck, and 12 pulse parallel connected thy bridge + boost with loss and temperature estimation in PSCAD and to validate the steady-state results obtained through EV charging topology based on Thyristor web simulation model.
Two different thyristor models and two different IGBTs have been chosen for the process of validation. The XML data of both these Thyristors and IGBTs which were 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), on-state voltage drop of IGBT (VCE), and on state voltage drop of the thyristor (VT) 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 Thyristors and IGBTs have been captured from the device datasheet while the Heat sink to ambient thermal resistance Rth(h-a) is assumed as 2 K/kW with different ambient temperatures.
7 test cases are simulated for two rectifier topologies and simulated in PSCAD and SEMIS by varying different parameters like input line to line voltage, device, Load power, firing angle, Switching frequency, Duty ratio etc.

Rectifier 1:   12 pulse series connected bridge + Buck/Boost
Rectifier 2: 12 pulse parallel connected bridge + Buck/Boost

Remark:

The following corrections and simplifications are made on PSCAD for 6 pulse and 12 pulse converters:

• The thyristor bridge model and the control to generate pulses from alpha on PSCAD is different from the converter built with individual thyristors and the control scheme on PLECS.
• A correction of -2.5˚to 3˚ was made to alpha on PSCAD w.r.t the alpha in PLECS for the 12 pulse  series connected rectifier and 12 pulse parallel connected rectifier respectively to achieve the same electrical parameters like real power, reactive power, phase voltages and currents on both the platforms.
• The correction in alpha is required to reduce the influence of the differences in the numerical approximation methods (conversion of the circuit to differential equations) employed by these software’s.
• This approach serves the purpose of estimating losses as similar powers are operated on both models.
• The errors shown in red may be ignored as this is a correction in the alpha to achieve the same AC and DC parameters.

 USER MANUAL REVISION HISTORY

PGGI/SD

SIMULATION SOFTWARE RELEASE HISTORY

ABB Power Grids Switzerland Ltd
Semiconductors
A Hitachi ABB Joint Venture
Fabrik Strasse 3
5600 Lenzburg, Switzerland
Phone: +41 58 586 1419
Fax: +41 58 586 1306
E-Mail: abbsem@hitachi-powergrids.com
www.hitachiabb-powergrids.com/semiconductors

Note
We reserve all rights in this document and in the information contained therein.
Reproduction, use or disclosure to third parties without expressed authority is strictly forbidden.
© 2020 Hitachi Power Grids. All rights reserved

References

• ABB Group. Leading digital technologies for industry — ABB Group
• Semiconductors

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