{"id":13842,"date":"2019-09-27T07:50:18","date_gmt":"2019-09-27T05:50:18","guid":{"rendered":"https:\/\/mag.ebmpapst.com\/en\/?p=13842"},"modified":"2025-08-21T08:39:00","modified_gmt":"2025-08-21T06:39:00","slug":"the-formula-for-current-harmonics","status":"publish","type":"post","link":"https:\/\/mag.ebmpapst.com\/en\/insights\/the-formula-for-current-harmonics_13842\/","title":{"rendered":"The formula for current harmonics"},"content":{"rendered":"\n<p>The need for data centers is growing world\u00adwide, just like the quan\u00adti\u00adties of data to be processed and the power density of the indi\u00advidual compo\u00adnents. In spite of this trend, the average annual power consump\u00adtion for air condi\u00adtioning in data centers fell by eleven percentage points in the past ten years, <br>mainly due to the increased use of adjustable and effi\u00adcient EC tech\u00adnology in fans.<\/p>\n\n\n\n<div class=\"wp-block-group alignfull mgznkr-cta-retrofit-banner\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<style>\n.mgznkr-cta-retrofit-banner .alignwide.banner-width {\n  max-width: 100%;\n  width: 1240px;\n  margin: 0 auto;\n--mark-bgcolor: #00a633;\n--mark-color: white;\n}\n@media (max-width: 781px) {\n.mgznkr-cta-retrofit-banner .wp-block-cover .wp-block-cover__image-background {\nobject-position: 17% 50%!important;\n}\n\n.mgznkr-column-spacer p {display: none; }\n}\n@media (min-width: 782px) {\n.mgznkr-column-spacer p a {\n  min-height: 290px;\n  min-width: 100%;\n  display: block;\n  border-radius: 50px;\nfont-size: 0;\n}\n}\n\n.mgznkr-cta-retrofit-banner .wp-block-columns .wp-block-column:first-of-type{\n    position:relative;\n}\n.mgznkr-cta-retrofit-banner .wp-block-columns .wp-block-column:first-of-type::before {\n    content: \"\";\n    position: absolute;\n    width: 170%;\n    height: 100%;\n    background: #a2b91e;\n    z-index: 0;\n    top: 0;\n    left: 0;\n}\n.mgznkr-cta-retrofit-banner .wp-block-column{\n    z-index: 10;\n    &:first-of-type{\n        padding-left: 4rem;\n    }\n}\n.mgznkr-cta-retrofit-banner .wp-block-column *{\nposition: relative;\nz-index: 10;\n}\n.mgznkr-cta-retrofit-banner .wp-block-column figure.wp-block-image{\n    margin-bottom: 0;\n}\n@media (width < 782px){\n.mgznkr-cta-retrofit-banner .mgznkr-mobile-hidden{\ndisplay: none;\n}\n.mgznkr-cta-retrofit-banner .wp-block-columns .wp-block-column:first-of-type{\n  padding-right: 4rem;\n}\n.mgznkr-cta-retrofit-banner .wp-block-columns .wp-block-column:first-of-type::before {\n  width: 100%;\n}\n}\n\n<\/style>\n\n\n\n<div style=\"height:32px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-cover\" style=\"min-height:350px;aspect-ratio:unset;\"><img decoding=\"async\" class=\"wp-block-cover__image-background wp-image-38370 size-large\" alt src=\"https:\/\/ebmpapst-7237.kxcdn.com\/de\/files\/2025\/08\/L2A-Awareness-Campaign-960x400.webp\" data-object-fit=\"cover\"><span aria-hidden=\"true\" class=\"wp-block-cover__background has-background-dim-0 has-background-dim\" style=\"background-color:#e0e6e6\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-block-cover-is-layout-constrained\">\n<div class=\"wp-block-columns alignwide banner-width is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<h2 class=\"wp-block-heading mgznkr-click has-white-color has-text-color has-link-color wp-elements-9c437f00d7951dd60554c7a2708cd1c5\" id=\"retrofit-banner-head\" style=\"font-size:1.6em;text-transform:uppercase\"><a href=\"https:\/\/www.ebmpapst.com\/de\/en\/campaigns\/industry-campaigns\/data-center.html#cooling-solutions\" target=\"_blank\" rel=\"noreferrer noopener\">High perfor\u00admance, low carbon:<\/a><\/h2>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p>ebm-papst reimag\u00adines data center cooling. Our effi\u00adcient cooling solu\u00adtions combine energy effi\u00adciency with high power density.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-fill mgznkr-click\" id=\"retrofit-banner-button\"><a class=\"wp-block-button__link has-background has-custom-font-size wp-element-button\" href=\"https:\/\/www.ebmpapst.com\/de\/en\/campaigns\/industry-campaigns\/data-center.html#cooling-solutions\" style=\"background-color:#0072bb;font-size:18px\" target=\"_blank\" rel=\"noreferrer noopener\">Ensure reli\u00adable cooling now <i class=\"mgznkr-icon fa fa-chevron-right fas\"><\/i><\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-bottom mgznkr-column-spacer mgznkr-mobile-hidden is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/de\/files\/2025\/08\/L2A-Awareness-Campaign-00-scaled.webp\" alt class=\"wp-image-38386\" style=\"object-fit:cover\"><\/figure>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:36px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n\n\n<div class=\"wp-block-image wp-image-13841\">\n<figure class=\"alignright size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"853\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/IMG_3846_GROB-FREI_COL_01GW.png\" alt class=\"wp-image-13841\" style=\"width:200px\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/IMG_3846_GROB-FREI_COL_01GW.png 268w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/IMG_3846_GROB-FREI_COL_01GW-260x828.png 260w\" sizes=\"auto, (max-width: 268px) 100vw, 268px\"><figcaption class=\"wp-element-caption\">Bern\u00adhard Siedler, Team Leader Air Condi\u00adtioning, ebm-papst Mulfingen (Foto: ebm-papst)<\/figcaption><\/figure>\n<\/div>\n\n<div class=\"wp-block-image wp-image-13839 size-article-300\">\n<figure class=\"alignleft size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"436\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Passiv-PFC_EN-e1568988756168.jpg\" alt class=\"wp-image-13839\" style=\"width:250px\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Passiv-PFC_EN-e1568988756168.jpg 800w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Passiv-PFC_EN-e1568988756168-260x142.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Passiv-PFC_EN-e1568988756168-660x360.jpg 660w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Passiv-PFC_EN-e1568988756168-450x245.jpg 450w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Passiv-PFC_EN-e1568988756168-300x164.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\"><figcaption class=\"wp-element-caption\">Current wave\u00adform with passive PFC<br>ebm-papst series product:<br>Power factor (\u03bb) = 0.94; THDI 33.5%<\/figcaption><\/figure>\n<\/div>\n\n\n<p>Modern motors are oper\u00adated with vari\u00adable frequency drives to exactly adjust their speed to require\u00adments, which results in nonlinear currents. A non-sinu\u00adsoidal current curve arises, which can be repre\u00adsented as a sum of sinu\u00adsoidal curves with frequen\u00adcies that are an exact multiple h of the funda\u00admental frequency. This is total harmonic distor\u00adtion (THDI), which is given in percent. A THDI of 33 percent means that in addi\u00adtion <br>to the 100 percent total active current, a 33 percent distor\u00adtion reac\u00adtive current is lost. The current harmonics also result in a heavy load on the supply network, distur\u00adbances, and high main\u00adte\u00adnance and replace\u00adment costs. So the aim is to mini\u00admize THDI. That is usually done with external passive or active filters that are barely able to reach a single-digit THDI&nbsp;value even with very high devel\u00adop\u00adment and vali\u00adda\u00adtion costs. They also involve other disad\u00advan\u00adtages such as space require\u00adments, high system complexity, or high procure\u00adment costs. The best approach is to prevent harmonics from arising in the first place.<\/p>\n\n\n<div class=\"wp-block-image wp-image-13840 size-article-300\">\n<figure class=\"alignleft size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"438\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Aktiv-PFC_EN-e1568988846985.jpg\" alt class=\"wp-image-13840\" style=\"width:250px\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Aktiv-PFC_EN-e1568988846985.jpg 800w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Aktiv-PFC_EN-e1568988846985-260x142.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Aktiv-PFC_EN-e1568988846985-660x361.jpg 660w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Aktiv-PFC_EN-e1568988846985-450x246.jpg 450w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/09\/Stromverlauf-mit-Aktiv-PFC_EN-e1568988846985-300x164.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\"><figcaption class=\"wp-element-caption\">Current wave\u00adform with active PFC<br>New ebm-papst product:<br>Power factor (\u03bb) = 0.99; THDI \u2264 5%<\/figcaption><\/figure>\n<\/div>\n\n\n<p>To do so, we devel\u00adoped the inte\u00adgrated 3-phase active PFC solu\u00adtion. \u201cActive recti\u00adfi\u00adca\u00adtion\u201d causes the input current to be sinu\u00adsoidal instead of pulsed, with the current curve shifted so that the current level and voltage are in phase. The power factor&nbsp; is an impor\u00adtant para\u00admeter, describing the ratio between effec\u00adtive power and apparent power. A value of&nbsp; = 1 is consid\u00adered optimum. By filtering the harmonics, the 3-phase elec\u00adtronics with active PFC in the RadiCal and RadiPac series of EC centrifugal fans reach&nbsp; = 0.99 and a THDI&nbsp;value of less than five percent. Compared with the industry stan\u00addard, active PFC tech\u00adnology reduces the costs for the required energy supply compo\u00adnents by about 38 percent.\u2002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The need for data centers is growing world\u00adwide, just like the quan\u00adti\u00adties of data to be processed and the power density of the indi\u00advidual compo\u00adnents. In spite of this trend, the average annual power consump\u00adtion for air condi\u00adtioning in data centers fell by eleven percentage points in the past ten years, mainly due to the [\u2026]<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"wp_typography_post_enhancements_disabled":false,"footnotes":""},"categories":[5,16,4,20],"tags":[],"class_list":["post-13842","post","type-post","status-publish","format-standard","hentry","category-electronics","category-fans","category-insights","category-motors"],"acf":[],"_links":{"self":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/13842","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/comments?post=13842"}],"version-history":[{"count":10,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/13842\/revisions"}],"predecessor-version":[{"id":21817,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/13842\/revisions\/21817"}],"wp:attachment":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/media?parent=13842"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/categories?post=13842"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/tags?post=13842"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}