{"id":38863,"date":"2019-11-10T14:53:21","date_gmt":"2019-11-10T14:53:21","guid":{"rendered":"\/forum\/forums\/topic\/power-ferrite-core-loss-model-use-of-kdc-maxwell-core-loss-with-dc-bias\/"},"modified":"2019-11-10T14:53:21","modified_gmt":"2019-11-10T14:53:21","slug":"power-ferrite-core-loss-model-use-of-kdc-maxwell-core-loss-with-dc-bias","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/power-ferrite-core-loss-model-use-of-kdc-maxwell-core-loss-with-dc-bias\/","title":{"rendered":"Power Ferrite Core Loss model use of Kdc (Maxwell Core Loss With DC Bias)"},"content":{"rendered":"<p>Hello Ansys Community.<\/p>\n<p><\/p>\n<p>I intend to reproduce inductor core losses of experimental results using Maxwell transient simulation. I have obtained the core losses using the B-H loop method (a.k.a. Two-wire method). The experiment was performed using a boost converter, so variations of current ripple, DC Bias and frequency could be made.<\/p>\n<p><\/p>\n<p>To achieve this, I setup the following Maxwell project:<\/p>\n<p><\/p>\n<ul><\/p>\n<li>A Maxwell Circuit simulation simulates the Boost Converter. The circuit is excited with the values of electrical measurements. The inductor of the circuit is assigned as an external winding (Maxwell 2D);<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<ul><\/p>\n<li>In Maxwell 2D I set the excitation to be the external circuit.<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<ul><\/p>\n<li>To characterize the material, I used experimentally measured B-H curve to set the relative permeability.<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<ul><\/p>\n<li>Core loss data (BP Curve) was set using manufacturer provided curves for two frequencies, 10kHz and 20kHz, for which the best fit is the <strong>Power Ferrite<\/strong> core loss model. The Steinmetz parameters obtained by Maxwell matched the manufacturer provided ones well. My measurements are in 10kHz.<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<p>The project reproduces reality very well: the output voltage matches the measurements, and so does the RMS and ripple current in the inductor. The problem is in core losses with DC Bias.<\/p>\n<p><\/p>\n<p>As far as I understand, the core loss curves provided by the manufacturer are measured given a sinusoidal excitation, and so should be the curves we provide Maxwell with. I believe that maxwell works out the whole non-sinusoidal excitation part by itself.<\/p>\n<p><\/p>\n<p>The manual isn&#8217;t very informative on DC-DC converter simulation, and the nature of the inductor waveforms (Nonsinusoidal + DC Bias) isn&#8217;t easily covered by models. This is where the guessing starts.<\/p>\n<p><\/p>\n<p>1. I <em>assume<\/em> that the <em>B <\/em>in the <em>BP <\/em>curve we provide Maxwell with is actually the Peak value of <em>B<\/em>. Given the DC Bias of my scenario, I <em>guessed<\/em> that Maxwell understands it as: Bpk = &Delta;B\/2. Am I correct? At least this is what matches manufacturer data. I could not find information about this on the manual.<\/p>\n<p><\/p>\n<p>2. In the user manual, on Section &#8220;Assigning Materials 9-39&#8221;, the equation through which the term <strong>Kdc<\/strong> affects the <strong>Electrical Steel <\/strong>core loss model is presented, but I haven&#8217;t been able to find anything about the <strong>Power Ferrite<\/strong> core loss model. In fact, I couldn&#8217;t even find the equation for Power Ferrite core loss model, but I have <em>guessed<\/em> that it is: Pv = Cm * f^x * B^y.<\/p>\n<p><\/p>\n<p>So how does the <strong>Kdc <\/strong>term comes into play here? I have been trying to <em>guess<\/em> how it works by trial and error, mainly assuming that it works exactly like it does for the <strong>Electrical Steel <\/strong>core loss model, as a simple multiplier inside the <strong>Cdc<\/strong> term, which would then multiply the <strong>Pv<\/strong> equation.<strong> Can I have confirmation on this?<\/strong><\/p>\n<p><\/p>\n<p>3. Also, I am aware that the program has an automated way of determining <strong>Kdc<\/strong> if I just leave it at zero, but then the results don&#8217;t agree with experimental data. I have also tested and confirmed that if I put in a very small value for <strong>Kdc<\/strong>, say, 1E-10, the results agree with experimental data for low DC Bias. It does act different that just leaving it at zero, which led me to believe that the use of <strong>Kdc <\/strong>for the<strong> Power Ferrite <\/strong>core loss model would be similar to the <strong>Electrical Steel<\/strong> core loss model.<\/p>\n<p><\/p>\n<p>4. My approach to determine the weight of DC Bias on material core loss is fitting the experimental results, but then again, without confirmation of how <strong>Kdc<\/strong> affects the <strong>Pv<\/strong> equation for <strong>Power<\/strong> <strong>Ferrite<\/strong>, it is difficult to work it out.<\/p>\n<p><\/p>\n<p>The main question here then is:<\/p>\n<p><\/p>\n<p><strong>How is the &#8220;Power Ferrite&#8221; core loss model affected by Kdc? <\/strong><\/p>\n","protected":false},"template":"","class_list":["post-38863","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["11042"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["1"],"_btv_view_count":["2032"],"_bbp_subscription":["244767"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["38863"],"_bbp_forum_id":["27793"],"_bbp_engagement":["170387","186019"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["148777"],"_bbp_last_active_id":["148777"],"_bbp_last_active_time":["2021-03-30 11:04:35"]},"test":"pbolsi"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/38863","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/38863\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=38863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}