# T-Type Inverter total losses **URL:** \ **Category:** PLECS\ **Tags:** losses, total, phi, svpwm0, t-type\ **Created:** [July 7, 2023, 9:15am UTC](https://forum.plexim.com/t/t-type-inverter-total-losses/1253 "2023-07-07T09:15:46Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Marianna](https://avatars.discourse-cdn.com/v4/letter/m/f19dbf/32.png) [@Marianna](https://forum.plexim.com/u/Marianna)\ **Post date:** [July 7, 2023, 9:15am UTC](https://forum.plexim.com/t/t-type-inverter-total-losses/1253/1 "2023-07-07T09:15:46Z")
Hi! I’m doing a study on the three-phase T-Type Inverter, the model of which can be downloaded from PLEXIM. In particular, I have to focus on how the total losses (which can be seen already from the downloaded model) change as phi changes. I have to vary phi from -180 to 180. By taking SVPWM1 Space Vector modulation (or others, like SPWM, THIPWM, THZSPWM), I get smaller losses when phi=0. In Space Vector SVPWM0, however, I have minimal losses at phi=30 (and phi=-150), and not at phi=0, as I expected. I can’t explain the reason why, I would need a little help. Thank you very much, Mary P.S: in attachments, under the name of “T-Type results” I put the Excel table and graph that compares SVPWM1 and SVPWM0. ---
**Author:** ![Kris\_Eberle](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/kris_eberle/32/6_2.png) [@Kris\_Eberle](https://forum.plexim.com/u/Kris_Eberle)\ **Post date:** [July 7, 2023, 4:24pm UTC](https://forum.plexim.com/t/t-type-inverter-total-losses/1253/2 "2023-07-07T16:24:46Z")
There are no attachments, but also we would need your model to understand how you modified the Plexim demo. ---
**Author:** ![Marianna](https://avatars.discourse-cdn.com/v4/letter/m/f19dbf/32.png) [@Marianna](https://forum.plexim.com/u/Marianna)\ **Post date:** [July 10, 2023, 5:26am UTC](https://forum.plexim.com/t/t-type-inverter-total-losses/1253/3 "2023-07-10T05:26:56Z")
Sorry, my mistake. Here it is all the needed attachments 🙂 Thank you for your attention! [T-Type results.pdf](https://forum.plexim.com/uploads/short-url/wVHABG3pUOx711LIR6YuQVhiXHa.pdf) (71.2 KB) [three\_phase\_t\_type\_inverter.plecs](https://forum.plexim.com/uploads/short-url/oSLKHbn0CzeMs3oNGh1bBPjZVkG.plecs) (468 KB) ---
**Author:** ![Bryan\_Lieblick](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/bryan_lieblick/32/10_2.png) [@Bryan\_Lieblick](https://forum.plexim.com/u/Bryan_Lieblick)\ **Post date:** [July 10, 2023, 3:36pm UTC](https://forum.plexim.com/t/t-type-inverter-total-losses/1253/4 "2023-07-10T15:36:35Z")
I can recreate your findings. I also assume that by SVPWM1 you’re referring to the first option in the 3-Phase Index-Based modulation component, DPWM0. If we look at the zero sequence injection shown in the component’s help for DPWM0, we can see that the zero sequence injection is phase shifted relative to the fundamental by 30 degrees. I suspect this is the reason why the loss profile is also shifted for this modulation scheme, as if the current peak occurs during the max/min duty cycle, then there will be less switching losses. Two of the papers referenced in the demo model (copied below) show the derivation of the theoretical loss profile for different modulation schemes. I would expect a theoretical analysis of the topic will reveal a similar shift in the loss profile. ![61](https://europe1.discourse-cdn.com/flex006/uploads/plecs/original/1X/bef070dae3c519737edfa0fa7d0e74fb7f076d68.jpeg) E. Serban, C. Pondiche, and M. Ordonez, “Power-loss analysis in 3-level TNPC inverters: Modulation effects,” in 2017 IEEE Energy Conversion Congress and Exposition (ECCE), Cincinnati, OH, 2017, pp. 490-497. Click to access online: [IEEE Xplore webpage](https://ieeexplore.ieee.org/document/8519612). ---
**Author:** ![Bryan\_Lieblick](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/bryan_lieblick/32/10_2.png) [@Bryan\_Lieblick](https://forum.plexim.com/u/Bryan_Lieblick)\ **Post date:** [July 10, 2023, 4:46pm UTC](https://forum.plexim.com/t/t-type-inverter-total-losses/1253/5 "2023-07-10T16:46:19Z")
Refer to [Figure 5.17](https://odr.chalmers.se/server/api/core/bitstreams/0f3479f4-9ea6-4da9-8745-19116d1e75de/content) of the attached two linked references showing similar behavior. Note that the DPWM numbering can vary from reference to reference.