{"id":13459,"date":"2025-07-23T12:53:31","date_gmt":"2025-07-23T10:53:31","guid":{"rendered":"https:\/\/mag.ebmpapst.com\/en\/?p=13459"},"modified":"2026-04-30T14:26:14","modified_gmt":"2026-04-30T12:26:14","slug":"active-power-factor-correction-minimizes-circuit-feedback","status":"publish","type":"post","link":"https:\/\/mag.ebmpapst.com\/en\/industries\/electronics\/active-power-factor-correction-minimizes-circuit-feedback_13459\/","title":{"rendered":"Active power-factor correc\u00adtion mini\u00admizes circuit feed\u00adback"},"content":{"rendered":"\n<p>The world badly needs energy-saving solu\u00adtions; from lighting right through to elec\u00adtrical drive systems. Even simply adapting the speed of drive systems to the actual torque\/power require\u00adments saves on unnec\u00ades\u00adsary power consump\u00adtion. The use of effi\u00adcient EC motors also taps into addi\u00adtional poten\u00adtial for savings, which bene\u00adfits the envi\u00adron\u00adment and the operator\u2019s running costs in equal measure. However, this very welcome devel\u00adop\u00adment has a catch: The input currents of the new energy-saving devices \u2013 which are gener\u00adally phase-shifted and pulsed as opposed to sinu\u00adsoidal \u2013 incur addi\u00adtional losses in the gener\u00ada\u00adtors, cables and trans\u00adformers of the power supply. The reac\u00adtive power caused by the phase shift and harmonic currents must be made avail\u00adable. This becomes an unwanted cost factor, partic\u00adu\u00adlarly in such isolated networks as the ones found in data centers. A solu\u00adtion needs to be found for this issue.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full xxtra wp-image-13463 size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1117\" height=\"472\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_1_Datacenter_System_EN.jpg\" alt class=\"wp-image-13463\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_1_Datacenter_System_EN.jpg 1117w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_1_Datacenter_System_EN-260x110.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_1_Datacenter_System_EN-660x279.jpg 660w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_1_Datacenter_System_EN-960x406.jpg 960w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_1_Datacenter_System_EN-450x190.jpg 450w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_1_Datacenter_System_EN-300x127.jpg 300w\" sizes=\"auto, (max-width: 1117px) 100vw, 1117px\"><figcaption class=\"wp-element-caption\">Figure 1: An example of a power supply system in a data center. (Graphic | ebm-papst)<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Circuit feed\u00adback caused by current harmonics<\/h2>\n\n\n\n<p>The power supply of a data center essen\u00adtially consists of a grid infeed trans\u00adformer, UPS system and a standby gener\u00adator (Fig. 1). Together, these compo\u00adnents must ensure a reli\u00adable power supply (through the prin\u00adciple of redun\u00addancy). On the other hand, the provi\u00adsion of addi\u00adtional reac\u00adtive power requires all compo\u00adnents involved in the power supply to deliver higher perfor\u00admance. Unnec\u00ades\u00adsary over-dimen\u00adsioning of this kind is unde\u00adsir\u00adable because of the asso\u00adci\u00adated costs.<\/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\n<p>However, as is the case for asyn\u00adchro\u00adnous motors with vari\u00adable-frequency drives, power-consump\u00adtion-opti\u00admized EC fans now have a pulsed \u2013 as opposed to sinu\u00adsoidal \u2013 current draw due to their circuitry, yet without needing addi\u00adtional measures. Every depar\u00adture from a sinu\u00adsoidal current draw brings about current harmonics, which largely lead to what is known as \u201cdistor\u00adtion reac\u00adtive power\u201d. This puts addi\u00adtional strain on the supply network and leads to increased losses in all compo\u00adnents involved in the power supply.<\/p>\n\n\n<div class=\"wp-block-image wp-image-13469 size-medium\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"994\" height=\"441\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_2_Harmonics_two-fans_EN.jpg\" alt class=\"wp-image-13469\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_2_Harmonics_two-fans_EN.jpg 994w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_2_Harmonics_two-fans_EN-260x115.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_2_Harmonics_two-fans_EN-660x293.jpg 660w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_2_Harmonics_two-fans_EN-960x426.jpg 960w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_2_Harmonics_two-fans_EN-450x200.jpg 450w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_2_Harmonics_two-fans_EN-300x133.jpg 300w\" sizes=\"auto, (max-width: 994px) 100vw, 994px\"><figcaption class=\"wp-element-caption\">Figure 2: Circuit feed\u00adback caused by harmonics in two fans with a rating of 3 kW. (Graphic | ebm-papst)<\/figcaption><\/figure>\n<\/div>\n\n\n<p>By way of an example, Fig. 2 shows the input current of a server cooling system with two fans arranged in parallel, each of which has a power consump\u00adtion of approx. 3 kW. At 6.69 kVA, the reac\u00adtive power is above the effec\u00adtive power of 5.74 kW in this case. The power factor, i.e. the quotient of effec\u00adtive power to apparent power, is a poor 0.64, while the total harmonic distor\u00adtion (THD(I)) of the current is around 120%. This means that the geometric sum of all harmonic currents is larger than the funda\u00admental compo\u00adnent itself. It is easy to conceive how such currents might place a signif\u00adi\u00adcant strain on all compo\u00adnents required in the power supply chain, i.e. trans\u00adformers, the UPS system, gener\u00ada\u00adtors, and even cables. The distor\u00adtion reac\u00adtive power must be main\u00adtained at the infeed point. In the interest of opti\u00admizing the power supply and backup system, the current distor\u00adtion should be as low as possible. In other words, the power factor should be close to a value of 1.<\/p>\n\n\n\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group illu\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"video-container\"><iframe loading=\"lazy\" class=\"vimeo-iframe\" src=\"https:\/\/player.vimeo.com\/video\/1102116671?dnt=1\" width=\"960\" height=\"540\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/div>\n\n<\/div><\/div>\n\n\n\n<p class=\"has-text-align-right like-figcaption\">(Video | ebm-papst)<\/p>\n<\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Regu\u00adla\u00adtory Stan\u00addards for Harmonic Currents in Three-Phase Equip\u00adment<\/h2>\n\n\n\n<p>The values stip\u00adu\u00adlated by stan\u00addard EN 61000-3-2, which applies to conven\u00adtional indus\u00adtrial systems, are insuf\u00adfi\u00adcient in this case. This stan\u00addard clas\u00adsi\u00adfies devices with a phase current of up to 16 A and defines harmonic-current limit values for these classes. Fans fall within equip\u00adment group A, which contains house\u00adhold appli\u00adances along\u00adside symmet\u00adrical, three-phase devices, for example.<\/p>\n\n\n<div class=\"wp-block-image size-full wp-image-13471\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"651\" height=\"643\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_3_Line_choke_EN.jpg\" alt class=\"wp-image-13471\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_3_Line_choke_EN.jpg 651w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_3_Line_choke_EN-260x257.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_3_Line_choke_EN-450x444.jpg 450w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_3_Line_choke_EN-300x296.jpg 300w\" sizes=\"auto, (max-width: 651px) 100vw, 651px\"><figcaption class=\"wp-element-caption\">Figure 3: Reducing circuit feed\u00adback by inte\u00adgrating a line choke upstream. (Graphic | ebm-papst)<\/figcaption><\/figure>\n<\/div>\n\n\n<div class=\"wp-block-group article-sidebox\"><div class=\"wp-block-group__inner-container is-layout-flow wp-block-group-is-layout-flow\">\n<div style=\"height:9px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/www.ebmpapst.com\/de\/en\/support\/downloads\/software\/active-pfc-whitepaper.html\" target=\"_blank\" rel=\" noreferrer noopener\"><img loading=\"lazy\" decoding=\"async\" width=\"1258\" height=\"1258\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/activepfc-whitepaper-en.jpg\" alt class=\"wp-image-21557\" style=\"aspect-ratio:4\/3;object-fit:cover;width:200px\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/activepfc-whitepaper-en.jpg 1258w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/activepfc-whitepaper-en-660x660.jpg 660w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/activepfc-whitepaper-en-960x960.jpg 960w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/activepfc-whitepaper-en-260x260.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/activepfc-whitepaper-en-300x300.jpg 300w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/activepfc-whitepaper-en-450x450.jpg 450w\" sizes=\"auto, (max-width: 1258px) 100vw, 1258px\"><\/a><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\">Power quality under control \u2013 no extra effort required!<\/h3>\n\n\n\n<p>Discover in the white paper how inte\u00adgrated active recti\u00adfi\u00adca\u00adtion makes EC fans ready for the toughest require\u00adments.<\/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\"><a class=\"wp-block-button__link has-custom-font-size wp-element-button\" href=\"https:\/\/www.ebmpapst.com\/de\/en\/campaigns\/industry-campaigns\/aktiv-pfc\/gated-content.html\" style=\"font-size:18px\" target=\"_blank\" rel=\"noreferrer noopener\">Read the white paper now <i class=\"mgznkr-icon fa fa-chevron-right fas\"><\/i><\/a><\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<p>The higher the input currents become, the more diffi\u00adcult it is to adhere to the limit values of Class A because these are absolute limit values (i.e. not rela\u00adtive to the respec\u00adtive output) defined for the indi\u00advidual clas\u00adsi\u00adfi\u00adca\u00adtions of the harmonic spec\u00adtrum. Only active filter solu\u00adtions can be of help from a certain input current level. For three-phase devices, however, these are extremely intri\u00adcate and not econom\u00adi\u00adcally attrac\u00adtive for \u201cnormal\u201d indus\u00adtrial appli\u00adca\u00adtions. This is perhaps the reason why three-phase devices with outputs of over 1 kW are not covered by the stan\u00addard. As a result, there are simply no limit values at all for three-phase devices with outputs of between 1 kW and approx. 10 kW. On the other hand, if multiple devices for which no limit values apply as indi\u00advidual devices are inter\u00adcon\u00adnected, and if the phase current is in a range of between 16 A and 75 A, an addi\u00adtional stan\u00addard applies: EN 61000-3-12 defines the limit values for indi\u00advidual clas\u00adsi\u00adfi\u00adca\u00adtions of the harmonic spec\u00adtrum and the total harmonic distor\u00adtion of the current. The inter\u00adesting aspect of this is that the permis\u00adsible values are depen\u00addent on the grid quality. The \u201csofter\u201d the grids are \u2013 that is to say, the higher the complex internal resis\u00adtance of the grid is \u2013 the lower the limit values for the harmonic content of the current will be. This is only logical: After all, a non-linear current distorts the voltage wave\u00adform more signif\u00adi\u00adcantly as the internal resis\u00adtance of the grid increases. In order to satisfy demands in this case, measures also need to be taken for classic vari\u00adable-frequency drives with a three-phase supply. Because a low level of internal resis\u00adtance can usually be assumed in most indus\u00adtrial grids, a limit value of 48% applies for the harmonic content in accor\u00addance with EN 61000-3-12.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Line chokes and DC-link chokes only help to a certain extent<\/h2>\n\n\n\n<p>This value, which still falls well short of satis\u00adfying the needs of today\u2019s data centers, can be achieved with rela\u00adtive ease, such as by installing a line choke upstream (Fig.\u20083). Nonethe\u00adless, such chokes require space and addi\u00adtional cabling. For the example mentioned above featuring 2 fans, each rated at approx. 3 kW, values of around 0.9 and 45% can be achieved for the power factor and total harmonic distor\u00adtion (THD(I)) respec\u00adtively with a 2% line choke.<\/p>\n\n\n<div class=\"wp-block-image size-medium wp-image-13473\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"682\" height=\"682\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_4_Dc-link_choke_EN.jpg\" alt class=\"wp-image-13473\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_4_Dc-link_choke_EN.jpg 682w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_4_Dc-link_choke_EN-260x260.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_4_Dc-link_choke_EN-660x660.jpg 660w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_4_Dc-link_choke_EN-300x300.jpg 300w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_4_Dc-link_choke_EN-450x450.jpg 450w\" sizes=\"auto, (max-width: 682px) 100vw, 682px\"><figcaption class=\"wp-element-caption\">Figure 4: Reducing circuit feed\u00adback by inte\u00adgrating a DC-link choke. (Graphic | ebm-papst)<\/figcaption><\/figure>\n<\/div>\n\n\n<p>Even better values can be achieved if a DC-link choke (Fig.\u20084) is incor\u00adpo\u00adrated into the power elec\u00adtronics (which is a stan\u00addard feature of ebm-papst EC fans with a three-phase supply and highly capac\u00adi\u00adtive DC link): The require\u00adments of stan\u00addard EN61000-3-12 are satis\u00adfied with a power factor of approx. 0.94 and a THD of 34%, at least as far as the limit values for \u201chard\u201d (i.e. low-imped\u00adance) indus\u00adtrial networks are concerned. However, in cases where the grid voltage distor\u00adtions are prob\u00adlem\u00adatic and\/or grid imped\u00adance levels are high, the harmonic content in the current must be reduced to a minimum. Conse\u00adquently, target values of over 0.95 for the power factor and a THD(I) of below 5% are now frequently stip\u00adu\u00adlated for many data-center appli\u00adca\u00adtions.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The target value for THD(I) is below 5%<\/h2>\n\n\n\n<p>Ballast solu\u00adtions in the form of harmonic filters (Fig. 5) are one theo\u00adret\u00adical option for approaching such values. These filters are quite impres\u00adsive with regard to their char\u00adac\u00adter\u00adis\u00adtics and the quality of mate\u00adrials used \u2013 a fact which is also reflected in the price tag. Nonethe\u00adless, the achiev\u00adable values do come very close to hitting the target: In the example here, a power factor value of 0.98 and a harmonic content of 7.5% in the phase current are achieved, while the current wave\u00adform is more or less sinu\u00adsoidal.<\/p>\n\n\n<div class=\"wp-block-image size-full wp-image-13475\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"656\" height=\"661\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_5_Harmonic_Filter_EN.jpg\" alt class=\"wp-image-13475\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_5_Harmonic_Filter_EN.jpg 656w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_5_Harmonic_Filter_EN-260x262.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_5_Harmonic_Filter_EN-450x453.jpg 450w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_5_Harmonic_Filter_EN-300x302.jpg 300w\" sizes=\"auto, (max-width: 656px) 100vw, 656px\"><figcaption class=\"wp-element-caption\">Figure 5: Reducing circuit feed\u00adback by connecting an expen\u00adsive harmonic filter upstream. (Graphic | ebm-papst)<\/figcaption><\/figure>\n<\/div>\n\n\n<p>Despite their bene\u00adfits, such filters often have the draw\u00adback of only being opti\u00admally designed for one single oper\u00adating point that gener\u00adally corre\u00adsponds to the rated output. In partial-load oper\u00ada\u00adtion, the THD(I) values are often twice as high. The power factor also dimin\u00adishes at lower output levels. As a result, the reac\u00adtive currents become very high in partial-load oper\u00ada\u00adtion. What is more, there is a consid\u00ader\u00adable voltage drop through the filter; the nominal speeds and output values of the fans might not actu\u00adally be reached under certain condi\u00adtions.<\/p>\n\n\n\n<p>The disad\u00advan\u00adtages of passive filters can be largely avoided by employing an active filter solu\u00adtion. Ballast devices are avail\u00adable in this case, although these are also more expen\u00adsive and require addi\u00adtional space and wiring effort.<\/p>\n\n\n\n<div class=\"wp-block-group mgznkr-elements mgznkr-box\"><div class=\"wp-block-group__inner-container is-layout-flow wp-block-group-is-layout-flow\">\n<h2 class=\"wp-block-heading\">Prob\u00adlems caused by harmonic currents<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Over\u00adloading of neutral conduc\u00adtors&nbsp;<\/li>\n\n\n\n<li>Over\u00adheating of trans\u00adformers&nbsp;<\/li>\n\n\n\n<li>Nuisance trip\u00adping of (minia\u00adture) circuit breakers&nbsp;<\/li>\n\n\n\n<li>Harmonic reso\u00adnance&nbsp;<\/li>\n\n\n\n<li>Skin effects&nbsp;<\/li>\n\n\n\n<li>Signal inter\u00adfer\u00adence<\/li>\n<\/ul>\n<\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Active PFC in fans as a plug &amp; play solu\u00adtion<\/h2>\n\n\n\n<p>With this in mind, the motor and fan special\u00adists at ebm-papst have made the fan manu\u00adfac\u00adturer the first to incor\u00adpo\u00adrate a three-phase, active PFC stage into their EC fans in the form of an active recti\u00adfier with the aim of saving the user addi\u00adtional effort (Fig. 6). This over\u00adhaul started with motor size 150 (3 kW), which can be found installed in the new RadiPac fan sizes 450, 500, and 560, in addi\u00adtion to RadiCal fan sizes 500, 560, and 630. The values which can be achieved actu\u00adally exceed require\u00adments: With a power factor of over 0.99 under the rated load, the THD(I) value is typi\u00adcally around 2%. The THD(I) value even stays below 5% all the way down to 10% of the rated output.<\/p>\n\n\n<div class=\"wp-block-image size-full wp-image-13477\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"649\" height=\"663\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_6_Active_PFC_EN.jpg\" alt class=\"wp-image-13477\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_6_Active_PFC_EN.jpg 649w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_6_Active_PFC_EN-260x266.jpg 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_6_Active_PFC_EN-450x460.jpg 450w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/03\/Fig_6_Active_PFC_EN-300x306.jpg 300w\" sizes=\"auto, (max-width: 649px) 100vw, 649px\"><figcaption class=\"wp-element-caption\">Figure 6: Reducing circuit feed\u00adback through active power-factor correc\u00adtion. A three-phase active PFC is incor\u00adpo\u00adrated into the EC motor\u2019s elec\u00adtronics. (Graphic | ebm-papst)<\/figcaption><\/figure>\n<\/div>\n\n\n<p>In the axial direc\u00adtion, the motors are only slightly longer due to the inte\u00adgra\u00adtion of the three-phase active PFC, while the loss of effi\u00adciency at the rated output is low at around 2%. Not only that, but the oper\u00adator still enjoys the advan\u00adtage of having the pulsed input current of the EC motors found in conven\u00adtional solu\u00adtions converted to a sinu\u00adsoidal input current without needing to wire in addi\u00adtional compo\u00adnents and without filters and motors needing to be matched to one another. The highly effi\u00adcient, plug &amp; play-capable EC fans reduce energy consump\u00adtion in data centers while also granting the wish of only having to design the power supply of such systems for the rated effec\u00adtive power of the fans.<\/p>\n\n\n\n<div class=\"wp-block-group mgznkr-elements mgznkr-box\"><div class=\"wp-block-group__inner-container is-layout-flow wp-block-group-is-layout-flow\">\n<h2 class=\"wp-block-heading\">Prob\u00adlems caused by harmonic volt\u00adages<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Voltage distortion\/voltage over\u00adshoots&nbsp;<\/li>\n\n\n\n<li>Over\u00adheating and starting prob\u00adlems with induc\u00adtion motors&nbsp;<\/li>\n\n\n\n<li>Zero crossing prob\u00adlems<\/li>\n<\/ul>\n<\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">RadiPac Centrifugal Fans with Active Power Factor Correc\u00adtion (PFC)<\/h2>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"842\" height=\"842\" src=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/ebmpapst_RadiPac_C_electronics.png\" alt class=\"wp-image-21546\" style=\"width:300px\" srcset=\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/ebmpapst_RadiPac_C_electronics.png 842w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/ebmpapst_RadiPac_C_electronics-660x660.png 660w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/ebmpapst_RadiPac_C_electronics-260x260.png 260w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/ebmpapst_RadiPac_C_electronics-300x300.png 300w, https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2019\/04\/ebmpapst_RadiPac_C_electronics-450x450.png 450w\" sizes=\"auto, (max-width: 842px) 100vw, 842px\"><figcaption class=\"wp-element-caption\">RadiPac 3 C (Image | ebm-papst)<\/figcaption><\/figure>\n<\/div>\n\n\n<p>The latest gener\u00ada\u00adtion of RadiPac centrifugal fans is equipped as stan\u00addard with EC motors featuring inte\u00adgrated elec\u00adtronics that include active power factor correc\u00adtion (PFC). This ensures that power consump\u00adtion is partic\u00adu\u00adlarly smooth and gentle on the grid\u2014an essen\u00adtial advan\u00adtage in sensi\u00adtive envi\u00adron\u00adments with strin\u00adgent require\u00adments for power quality. Thanks to active PFC, the power factor is signif\u00adi\u00adcantly improved, mini\u00admizing harmonic distor\u00adtion and ensuring compli\u00adance with inter\u00adna\u00adtional stan\u00addards such as EN 61000-3-2. The inte\u00adgrated control circuitry regu\u00adlates current draw so that it remains in phase with the line voltage, thereby reducing reac\u00adtive power and improving overall system effi\u00adciency. Combined with aero\u00addy\u00adnam\u00adi\u00adcally opti\u00admized impellers, compact design, and high power density, RadiPac fans offer a highly effi\u00adcient solu\u00adtion for demanding data center appli\u00adca\u00adtions.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The world badly needs energy-saving solu\u00adtions; from lighting right through to elec\u00adtrical drive systems. Even simply adapting the speed of drive systems to the actual torque\/power require\u00adments saves on unnec\u00ades\u00adsary power consump\u00adtion. The use of effi\u00adcient EC motors also taps into addi\u00adtional poten\u00adtial for savings, which bene\u00adfits the envi\u00adron\u00adment and the operator\u2019s running costs in [\u2026]<\/p>\n","protected":false},"author":12,"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":[5,16,15],"tags":[],"class_list":["post-13459","post","type-post","status-publish","format-standard","hentry","category-electronics","category-fans","category-telecommunication"],"acf":[],"_links":{"self":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/13459","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\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/comments?post=13459"}],"version-history":[{"count":41,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/13459\/revisions"}],"predecessor-version":[{"id":22938,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/13459\/revisions\/22938"}],"wp:attachment":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/media?parent=13459"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/categories?post=13459"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/tags?post=13459"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}