# Loss Discrepancy Between PLECS Thermal Model and Fuji Electric Online Simulator (7MBR50VD120-50) **URL:** \ **Category:** PLECS\ **Tags:** plecs, thermal-model, switching-losses, conduction-losses\ **Created:** [February 3, 2026, 6:23am UTC](https://forum.plexim.com/t/loss-discrepancy-between-plecs-thermal-model-and-fuji-electric-online-simulator-7mbr50vd120-50/2830 "2026-02-03T06:23:29Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![yashaswini](https://avatars.discourse-cdn.com/v4/letter/y/e68b1a/32.png) [@yashaswini](https://forum.plexim.com/u/yashaswini)\ **Post date:** [February 3, 2026, 6:23am UTC](https://forum.plexim.com/t/loss-discrepancy-between-plecs-thermal-model-and-fuji-electric-online-simulator-7mbr50vd120-50/2830/1 "2026-02-03T06:23:29Z")
Hi Plecs team, I am fairly new to plecs and I have developed a three-phase, two-level inverter in PLECS using sinusoidal PWM. For the loss and thermal analysis, I am using the Fuji Electric IGBT module **7MBR50VD120-50** , with the IGBT and diode thermally modeled based on the parameters provided in the datasheet. After performing the steady-state analysis in PLECS, I calculated the conduction and switching losses and compared them with the results obtained from the Fuji Electric online simulator under what I believe are equivalent operating conditions. However, I am observing a significant discrepancy between the two sets of results. I would appreciate any guidance on what aspects of my PLECS model might need adjustment (for example, device parameters, switching loss modeling, modulation assumptions, thermal setup, or operating conditions) in order to obtain loss values that are closer to those reported by the Fuji Electric online simulator. attaching the simulation and xml files for reference Thank you very much for your time and support. Any suggestions or best practices for aligning PLECS simulations with manufacturer-provided simulation tools would be greatly appreciated. Best regards, Yashaswini [fuji\_typeg.plecs](https://forum.plexim.com/uploads/short-url/p1YViVz3ELDJT6qcQxoJgQRIjqv.plecs) (94.7 KB) [new\_fuji.xml](https://forum.plexim.com/uploads/short-url/qFgLGpwES3Vif5AJGR4ScXCjmUd.xml) (171.8 KB)(igbt xml file) ---
**Author:** ![yashaswini](https://avatars.discourse-cdn.com/v4/letter/y/e68b1a/32.png) [@yashaswini](https://forum.plexim.com/u/yashaswini)\ **Post date:** [February 3, 2026, 6:24am UTC](https://forum.plexim.com/t/loss-discrepancy-between-plecs-thermal-model-and-fuji-electric-online-simulator-7mbr50vd120-50/2830/2 "2026-02-03T06:24:00Z")
was not able to add diode xml file earlier adding it now [new\_fuji\_diode.xml](https://forum.plexim.com/uploads/short-url/l1TABXSqDvmzhJ2Pt3Rr2PVz0BN.xml) (134.1 KB) the plecs model losses are: IGBT Conduction : 1.74W Turn on loss : 0.4744W Turn off loss : 1.7815W DIODE Conduction loss : 0.2726W Reverse recovery loss: 0.1617W Fuji electric online simulator losses IGBT Conduction : 1.54W Turn on loss : 0.47W Turn off loss : 1.15W DIODE Conduction loss : 0.45W Reverse recovery loss: 1.07W the input parameters for both are same ---
**Author:** ![RetoChristen](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/retochristen/32/1225_2.png) [@RetoChristen](https://forum.plexim.com/u/RetoChristen)\ **Post date:** [February 5, 2026, 8:58am UTC](https://forum.plexim.com/t/loss-discrepancy-between-plecs-thermal-model-and-fuji-electric-online-simulator-7mbr50vd120-50/2830/3 "2026-02-05T08:58:15Z")
Thanks for sharing the model and the XML files. I had a look at the setup and I don’t see any major issues in your PLECS model. The device modeling, loss calculation approach, and thermal setup all look reasonable and consistent. One minor point is that you are constructing the PWM generator manually instead of using the built-in PWM blocks available in PLECS. While this is perfectly valid, it does introduce an additional source of potential differences. In particular, details such as dead-time implementation, carrier type (sawtooth vs. symmetrical), comparator logic, and any additional gating logic can all influence switching behavior and therefore the calculated losses. It is also important to note that the internal assumptions and implementations used in the Fuji Electric online simulator (e.g., PWM strategy, dead-time handling, current ripple assumptions, switching loss interpolation, or internal derating factors) are not publicly documented. For this reason, it is not possible to make further detailed comments on the simulator’s results or to guarantee a close numerical match. In practice, some discrepancy between PLECS and manufacturer-provided simulation tools is expected unless all modulation, operating conditions, and loss modeling assumptions are matched very closely. If tighter agreement is required, I would recommend carefully aligning PWM details (especially dead-time and carrier definition) and double-checking that the electrical operating points (DC-link voltage, modulation index, current amplitude and phase, switching frequency, and temperature) are truly identical in both tools. Hope this helps. Best regards, Reto ---
**Author:** ![yashaswini](https://avatars.discourse-cdn.com/v4/letter/y/e68b1a/32.png) [@yashaswini](https://forum.plexim.com/u/yashaswini)\ **Post date:** [February 5, 2026, 9:33am UTC](https://forum.plexim.com/t/loss-discrepancy-between-plecs-thermal-model-and-fuji-electric-online-simulator-7mbr50vd120-50/2830/4 "2026-02-05T09:33:53Z")
Thank you for taking the time to review and greatly appreciate the confirmation. Based on your suggestion, I will rework the model using the built-in PWM blocks in PLECS and align the carrier definition and dead-time handling as closely as possible, to check whether this reduces the discrepancy in the calculated losses. I also wanted to ask if there are any recommended best practices or checks within PLECS to ensure that the loss estimation error stays within a reasonable bound, say ±10%, when comparing against manufacturer-provided simulation tools. For example, are there specific parameters, custom tables, assumptions, or validation steps that you would typically focus on to improve confidence in the loss results? Best regards, Yashaswini ---
**Author:** ![RetoChristen](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/retochristen/32/1225_2.png) [@RetoChristen](https://forum.plexim.com/u/RetoChristen)\ **Post date:** [February 5, 2026, 9:41am UTC](https://forum.plexim.com/t/loss-discrepancy-between-plecs-thermal-model-and-fuji-electric-online-simulator-7mbr50vd120-50/2830/5 "2026-02-05T09:41:23Z")
Dear @yashaswini To clarify, we do not have insight into the internal implementation or assumptions of the Fuji Electric online simulator. Since its PWM strategy, loss modeling, and internal settings are not documented and not accessible to us, we cannot comment on or explain its results. Best regards, Reto ---
**Author:** ![yashaswini](https://avatars.discourse-cdn.com/v4/letter/y/e68b1a/32.png) [@yashaswini](https://forum.plexim.com/u/yashaswini)\ **Post date:** [February 5, 2026, 9:44am UTC](https://forum.plexim.com/t/loss-discrepancy-between-plecs-thermal-model-and-fuji-electric-online-simulator-7mbr50vd120-50/2830/6 "2026-02-05T09:44:12Z")
Thank you very much for your help