Melcosim IGBT Loss Simulator

Transcription

1 Application NOTES: First Release May 17, 2005 Melcosim IGBT Loss Simulator Software Disclaimer Powerex assumes no responsibility for the use of this software and makes no guarantees, expressed or implied, about the quality, reliability, accuracy or any other characteristic of this software or the results obtained. The loss simulation program provides a comprehensive means of evaluating many Powerex IGBT products in inverter and chopper type applications. Given a set of operating conditions the loss simulator calculates power module losses and module junction temperatures that aid the design engineer in properly selecting Powerex products. Three modes of operation are available, two modulation schemes based on a three leg inverter topology and one based on a chopper topology. The current version, Ver. 2.00, may be downloaded from Mitsubishi through the Powerex website ( Registration with both Powerex and Mitsubishi is required. The Loss Simulation Program is compatible with Microsoft Windows 98SE and newer Windows versions. Getting Started To download the Melcosim LossSimulator log onto the Powerex website, and click on the Average Loss Simulation Software Icon in the lower left corner of the Powerex webpage. The Powerex User page will appear. If you already have a Powerex user ID and password enter you ID and password in the appropriate boxes and click on Login. If you are not a Powerex User click on Register Now. On the Register Now page all required information is flagged by the word reguired. After completing the required fields click on Continue. Click on the Average Loss Simulation Software*. Another Registration page will appear. Please fill out the appropriate information and click Submit. Required information on this page is indicated by an asterisk. Another webpage will appear; click on the Download icon. A file download window will appear; click save. After the download is complete there will be a zipped folder on your computer with a file name of the form Melcosim_Ver_YY_MM_VV. The zipped folder may be copied and shared; however, once the folder is unzipped the program cannot be shared as it will longer work on other computers. Unzip the contents of this folder by clicking on the Melcosim.exe icon. A new folder will be created for the unzipped contents. You are now ready to use the Loss Simulation program. To start the program, go to the folder created by unzipping process and click on the Program Icon. The opening screen will appear with a small window indicating how long that the simulator will continue to function. To remove this reminder, just click OK. Please note that the Simulator is being continuously improved and newer versions or updated data files may be available for download. If your version has expired or the module that you wish to use is not in your current version just go and download the latest version. If you enter you username and password you will not be required to fill out the Powerex registration window; however, the Mitsubishi 1

2 registration window will need to be completed each time a new version is downloaded. The current version number and data file number are displayed at the top of the Mitsubishi registration page. Current users can determine if they have the latest version or data file without going through the down load procedure. Running a simulation This is the main window: The opening window consists of the menu bar, the tool bar and an analysis window organized into four sections: Target Device: The power module that will be used during the simulation. The power module will be selected by the user. Application Conditions: This section sets up the operating conditions that will be used during the simulation. The operating conditions will be entered by the user. Device Data Profile: This section displays pertinent thermal data for the target device. Calculation Results: This section displays the different power losses, temperature rises and junction temperatures calculated by the simulation as a function of the Application conditions. 2

3 Running a simulation is easy and straight forward. First, select a Target Device; next enter the Application Conditions and Start the simulation. The results will be displayed in the Calculation Results Section. Selecting a Target Device Select a device for the analysis by clicking the Module Menu on the menu bar or by clicking on the Module select icon on the tool bar. The Module select window will appear on the screen. A module may be selected in two ways. First, a module may be selected by selecting the series and then the Module within the series or by selecting the module from an all inclusive list of all the modules in the simulator. To select a module family, click the arrow symbol on the series box; a list of available module families will appear. Just click on the family of choice and the selected family will appear in the Series box. Now click on the arrow symbol on the Module box and a list of module part numbers within the family will appear. Click on the desired Module part number. The selected part number will appear in the Module box. Click OK and the Module Select window will disappear. Second, a module may also be selected by clicking on the arrow symbol on the Module box first. In this case a list of all available modules will appear. Select the desired module from the list by clicking on the Module part number. The module part number will appear in the Module box. Click Ok and the Module Select window will disappear. In either case, the selected module part number will be in the Target Device box on the main window along with device data profile information being shown and initial application conditions. Setting the Application Conditions Having selected the Module, the application conditions should be reviewed and changed to meet your application conditions. The Application Conditions section consists of several parameters that you may change to fit the simulator to your application: Modulation selects the modulation scheme used in the analysis. o 3-Arm represents a sine coded inverter circuit. o 2-Arm represents a three phase inverter circuit in which the PWM pattern is varied such that each device is subject to switching for two-thirds of a cycle. See the section titled Two Arm Modulation for a description of this modulation scheme. o Chopper represents a chopper circuit typically used in DC to DC converter circuits. Io: - This is the circuit output current. Either Peak or RMS current values may be selected. The default is the Peak. Note: the Chopper scheme only allows the Peak value to be used. Vcc: - This is the circuit DC bus voltage. Fsw: - This is the switching frequency Rg: - This is the gate resistance value. On modules such as IPMs that don t require an external gate resistor Rg will be displayed as a dash. 3

4 PF: - This is the output power factor. Note, that the any PF value less than one must be entered with a leading zero. 0.7 is ok;.7 is not ok. Modulation Ratio: - The modulation ratio is the ratio of the modulation signal to the carrier signal. A modulation ratio of 1 means that the amplitude of the modulation signal and the carrier signal are equal. Note, the any Modulation Ratio value less than one must be entered with a leading zero is ok;.65 is not ok. Duty: - This is the ratio of on time to cycle time in the chopper mode. Modulation ratio is selected by the simulator when the duty value changes. Note, the any Duty value less than one must be entered with a leading zero. 0.8 is ok;.8 is not ok. Tf: - This is the heat sink temperature under the IGBT module. The simulator uses the thermal resistance values that relate to temperatures directly under the chip. Changes may be made by clicking the condition to be changed, deleting the current entry and typing in the new value. Conversely, one may continually press the tab button until the condition is selected and a new value may be entered with first deleting the contents. Running a Simulation Having selected a module and entered the appropriate application condition parameters complete the simulation by either clicking the Calculate menu item or by clicking the equal sign Icon on the toolbar. Results The Calculation results section displays the results of the simulation. Total losses for one IGBT in the module Total losses for one Free Wheeling Diode in the Module Total losses for all the IGBTs in the module Total losses for all the diodes in the Module total losses t from base plate directly under the IGBT chips to the IGBT junction t from base plate directly under the diode chips to the diode junction Conduction losses for one IGBT in the module Switching losses for one IGBT in the module Switching losses for one diode in the module Conduction losses for one diode in the module Base plate temperature The IGBT junction temperature given the heat sink temperature The diode junction temperature given the heat sink temperature 4

5 The Results as well as the application conditions may be saved to the Windows clipboard by selecting the Edit menu or by pressing the double page Icon on the tool bar. The data is saved in text format that can be pasted into text editors or word processors for viewing, printing. This same text output can be printed directly by pressing the printer Icon on the tool bar or be using the print command in the File menu. [Application Conditions] Target Device: PM50CLA060 Modulation: 3-Arm (Standard) Io: 25.0 A (peak) Vcc: V fsw: 5.0 khz Rg: - Ohm PF: 0.8 Modulation Ratio: 1.0 Tf: 90.0 degree(centigrade) Just under the chip. [Calculation Results] Power Losses(Average) P(IGBT):Total W/Device DC: 6.75 W/Device SW: 4.40 W/Device P(Diode):Total 2.20 W/Device DC: 1.78 W/Device SW: 0.42 W/Device P(IGBT): W/Module(INV.part) P(Diode): W/Module(INV.part) P(Total): W/Module(INV.part) Temperature Rises(Average) Delta-Tj-c(IGBT): degree(centigrade) Delta-Tj-c(Diode): 3.54 degree(centigrade) Tc(under the chip): degree(centigrade) Tj(IGBT): degree(centigrade) Tj(Diode): degree(centigrade) Note: These calculation results does not include a ripple. The ripple should be considered especially for an output frequency. Example of the Text Output Format 5

6 Menus MENU MENU ITEM DISCRIPTION File New Opens a new simulation window (Ctrl-N is the short key). Close Closes the active window. Export Saves the simulation data as a text file. Print Prints the current active window contents to the default printer (Ctrl-P is the short key). Print Preview Displays document to be printed. Print Setup Configures the printer for the desired document format. Exit Closes the simulation program. Edit Copy Places the simulation results on the Windows clipboard. Does not work in graph mode. Module Displays the Module selection window. Calculate Cause the simulation to run. Graph Conditions Displays the normal simulation window. Temperature vs. Current Displays the junction temperature for both the diode and the IGBT versus collector current. Temperature vs. sw. Frequency Displays the junction temperature for both the IGBT and the diode versus switching frequency. Power vs. Current Displays the power loss in both the IGBT and the diode versus the peak collector current. Power vs. sw. Frequency Displays the power loss in both the IGBT and the diode versus the switching frequency. Max. Current vs. sw. Frequency Displays the Maximum peak collect current in both the IGBT and the diode versus switching frequency while maintaining the junction temperature at 125 C. Tj vs. Icp & P vs. Icp Displays the combined results of the Temperature vs. Current graph and the Power vs. Current graphs. Tj vs. Fsw & P vs. Fsw Displays the combined results of the Temperature vs. sw. Frequency and the Power vs. sw. Frequency graphs. Tj vs. Fsw & max Icp vs. Fsw Displays the combined results of the Temperature vs. sw. Frequency and the Max. Current vs. sw. Frequency graphs. P vs. Fsw & max Icp Displays the combined results of the Power vs. sw. Display View Window vs. Fsw Tj max Grid Frame Title Back Color Toolbar Status Bar New window Cascade Frequency and the Max. Current vs. sw. Frequency graphs. Allows the user to set the maximum junction temperature for the simulation. The maximum junction temperature cannot exceed 150 C. Turns on the grid on the graphs. Turns on a frame around the graph. Turns on the graph title. Allows changes in the graph background color. Turns on the Icon Toolbar at the top of the simulator window. Turns on the status bar at the bottom of the simulator window. Opens a new simulation window. Arranges all open simulation windows in cascade format in which all windows are overlaid so that each window header is visible. Tile Arranges all open simulation windows as tiles in a floor. Equal portions of all open windows are visible. Arrange Icons Future use. Help About Melcosim Displays version information. 6

7 Toolbar Icons, their meaning and usage ICON FUNCTION Starts a new simulation window Opens the module selection window New conditions (for future use) Runs the simulation. The two bars turn red after a module has been selected. The simulation will not run until the bars are red. Saves the simulation results in a text file. Graphs are save as a.csv (Comma Separated Value) text file. This type of file may be opened using Microsoft Excel, Word or most text editors. Copies the simulation results to the Microsoft clipboard. Graphs cannot be copied to the clipboard Prints the simulation results in text or any of the available graphs using the default printer. Each item must be printed separately Provides information about the Loss Simulator Error Messages Error messages are displayed in pop up windows whenever a recommended application condition or parameter has been exceeded or the value entered is not of the correct form. Note that all values between -1 and 1 must have a leading zero (0.5 is ok.5 is not) or a message will display in the form <parameter name> is illegal!! Message The value for MAX Tj must be 150.0[decC] or less! The value for MAX Tj must be 25.0[decC] or more! Modulation Ratio is illegal!! The value for Rg must be xx.x[ohms] or more! The value of Rg must be xx.x[ohms] or less! The value of Icp must be xxx.x[a] (peak) or less! Tj is too high. This application is not recommended. Meaning The maximum junction temperature has been set to greater than 150 C in the Graph/Tj max menu. Enter a value of 150 C or less. The maximum junction temperature has been set to less than 25 C in the Graph/Tj max menu. Enter a value of 25 C or more. The modulation ratio is missing a leading zero, the value is blank. The Rg value is less than recommended for the particular module. The program will calculate the results regardless of the Rg value being set too low. The Rg value is greater than recommended for the particular module. The program will calculate the results regardless of the Rg value being set too high. The Icp value is greater than recommended for the particular module and application. The program will calculate the results regardless of the Icp value being set too low. The calculations yield a junction temperature in excess of 150 C for the application conditions. 7

8 Message The value for Vcc must be xxx.x[v] or less! The value for Vcc must be xxx.x[v] or more! Vcc value is illegal!! Meaning The Vcc value is higher than recommended for use with this module. The xxx.x will be for 600 volt modules, for 1200 volt modules, and for 1700 volt modules. The program will calculate the results regardless of Vcc being set to high. The VCC value is lower than recommended for use with this module. The xxx.x will be for 600 volt modules, for 1200 volt modules, and for 1700 volt modules. Note that IGBT operation is possible at less than the minimum voltage given in the message. The program will calculate results regardless of Vcc being set too low. The value for Vcc is negative or blank. You must enter an acceptable value before the simulation will run. The value for Fsw must be xx.x[khz] or less! The switching frequency is higher than the recommended value for the module. The program will run regardless of the switching being set too high. The value for Tf must be 25.0[deg C] or more! The value for Tf must be 125.0[deg C] or less! Icp value is illegal!! The Tf value is less than 25.0 C. The program will run regardless of the Tf value used. The Tf value is greater than C. The program will run regardless of the Tf value used. Icp is blank or Icp is negative. You must enter an acceptable value before the simulation will run. Fsw value is illegal!! Fsw is blank or Fsw in negative or Fsw is less than 1 khz and the leading zero is missing. You must enter an acceptable value before the simulation will run The Pf value is illegal!! The Pf value is blank or missing the leading zero. The value for Modulation Ratio must be 0.0 or more! The Modulation Ratio value is negative. Enter a value for the Modulation Ratio from 0.0 to 1. Duty value is illegal!! The Duty value is blank or missing a leading zero The value for Modulation Ratio must be or less! The Modulation Ratio has been set greater than 1. Enter a value between 0.0 and 1 The value for the Pf must be or less! The Pf value is set to greater the 1. Enter a Pf value from -1 to 1. The value of Pf must be -1.0 or more! The Pf value is set to less the -1. Enter a Pf value from - Rg do not set. Software Notes: 1 to 1 An Rg value has been entered for a Intelligent Power Module (IPM) that does not require an Rg. The program will ignore the value and remove it from Rg text box. 1. Ripple is not included in the simulation. The program assumes a sine wave current shape for the inverter simulation. For the chopper the program assumes a constant current output (i.e. perfect filtering). 2. Because the program allows calculations to be performed beyond the intended ranges of various operating conditions, the program may calculate results impossible to achieve in the real world. 3. IGBT calculations are based on 125 C for both conduction and switching; diode calculations are based on 125 C for switching and 25 C for conduction resulting in losses and temperatures slightly higher than real world results. 8

9 Two Arm Modulation Two arm modulation, sometimes called discontinuous modulation, provides a means of reducing the switching losses in a standard inverter circuit by one-third. Basically, a neutral voltage is added to fundamental phase voltages before comparison to the carrier waveform. If you start with the above three phase sine waves and add the neutral wave you get the following waveforms. The equation for any one waveform is of the form: V-n(t)=Vphase(t)+Vneutral(t). Were V-n is Van, Vbn and Vcn. The neutral voltage wave form drops out when looking from line to line. For Vab: Vab=Va-Vb = (Van + Vneutral)-(Vbn+Vneutral) = Van-Vbn. These are then compared to the carrier frequency wave form, typically a triangle wave form to form the pwm ave form needed to control the IGBT The result is a sine wave fundamental voltage impressed on the load with two thirds the switching losses as compared to the traditional sine coded PWM approach. 9