靜電放(fang)電，傳(chuan)導幹擾，電磁(ci)兼(jian)容，耦合(he)輻(fu)射

The phenomenon of electromagnetic interferences
Depending on the kind of coupling of electromagnetic disturbances the phenomenon are divided into two different groups. In case the disturbance signal is air-borne one speaks of radiated interference while in case of disturbance signals are line-carried one speaks of conducted interference.

Where the coupling is radiation
Stationary and non-stationary radio transmitters (Electrical Field)
Both stationary high-power radio transmitters and non-stationary walkie-talkies or ecommunication devices operating in the immediate vicinity of systems or equipment lead to uncontrolled electromagnetic radiation into vulnerable electronic equipment.
Parameters: Narrow-band, continuous electromagnetic interference (modulated).
Standard reference: IEC/EN 61000-4-3 

HV power supply transmission lines (Magnetic Field) 
In the close vicinity to these lines high magnetic fields can be generated and coupled into other electronic or electrical systems.
Parameters: Narrow-band with 16 2/3Hz or 50/60Hz, continuous electromagnetic interference
Standard reference: IEC/EN 61000-4-8 

Indirect lightning effects (pulsed Magnetic Field) 
Lightning strokes into HV voltage power distribution systems are causing high electromagnetic fields which are able to cause induced voltage in any low voltage distribution system, such as power mains systems. Also ecom networks, due to the extended distribution of cabling, are threatened by indirect lightning effects.
Parameters: Range of voltage some tens of kilovolts, range of current some hundreds of amps, high-energy pulses with rise times in the microsecond range.
Standard reference: IEC/EN 61000-4-9

Where the coupling is conduction
Inductive load switching results in Electrical fast transients (burst)
Electromagnetic influences produced in the neighborhood by rapid variation of voltage and current as a result of the abrupt change of a switch from a non-conductive to a fully conductive status or vice versa, e.g. switching inductive loads with mechanically moved contacts between which arcing occurs before they separate.
Parameters: Broad-band pulse interference, rise time of pulses of a few nanoseconds, small energy content and high repetition rate.
Standard reference: IEC/EN 61000-4-4 

Switching inductive or capacitive loads in power mains supply system 
Switching heavy inductive or capacitive loads in low voltage power mains supply systems are causing transients of high energy and high voltage, depending on the installation category.
Parameters: Range of voltage some up to tens of kilovolts, range of current some tens of kilo amps, high-energy pulses with rise time and duration in the microsecond range.
Standard reference: IEC/EN 61000-4-5 

Atmospheric discharges such as lightning 
Lightning strokes into high voltage power distribution systems are causing transients in low voltage power mains networks. Via coupling these transients can also be detected in data bus systems, I/O lines and any cabling in the industrial area.
Parameters: Range of voltage some tens of kilovolts, range of current some tens of kilo amps, high-energy pulses with rise times in the microsecond range.
Standard reference: IEC/EN 61000-4-5 

Power Mains supply failures 
Voltage dips and short interruptions are caused by faults in the network, in installations or by a sudden large change of load. In certain cases, two or more consecutive dips or interruptions may occur. Voltage variations are caused by continuously varying loads connected to the mains supply network.
Parameters: These phenomena are random in nature and can be characterized in terms of the deviation from the rated voltage and duration.
Standard reference: IEC/EN 61000-4-11 

Electrostatic discharge 
ESD occurs when the static electric field between two objects exceeds the dielectric strength of the air between them. The discharge is a complex event involving a local transfer of charge at the point of discharge, electromagnetic near field coupling between the objects involved, induced current flow in the object receiving the discharge and radiated electromagnetic energy from the charged object as well as from the arc of the discharge. All of these phenomenon are capable of causing malfunctions and, in some cases, damage in electronic equipment.
Parameters: The major effects are generated by the discharge current (< 100A) and voltage (< 30kV) with rise times in the nanosecond and even in the picosecond range.
Standard reference: IEC/EN 61000-4-2 

Conducted disturbances, induced by radio-frequency fields 
Conducted radio-frequency disturbance occurs from intended rf transmitters affecting cables such as mains supply lines, signal lines or earth connections between different parts of an electrical or electronic systems.
Parameters: The interference signal is a an amplitude modulated or pulse modulated signal, typically in the frequency range between 9kHz and 80MHz, sometimes extended to 230MHz.
Standard reference: IEC/EN 61000-4-6 

Harmonic current emission 
With an increasing number of electronic power supplies used in a wide range of products the aim to limit the harmonic current emission has become more and more important. It is a specific interest of the power distribution companies to keep the harmonic current emission to a considerable low level as harmonic current causes unnecessary loading of the power distribution infrastructure. This again may affect both quality and reliability of the power supply.
Parameters: Harmonic currents are measured up to the 40th harmonic of the fundamental. Limits for each harmonic are specified depending on the type of product.
Standard reference: IEC/EN 61000-3-2, IEC/EN 61000-3-12 

Voltage changes, voltage fluctuation and flicker 
During an entire duty-cycle of a product sudden voltage changes, voltage fluctuations or flicker might occur. This may effect the quality of the mains supply voltage. Flicker can be visually recognized as the illumination strength of a lamp may drop significantly even for a very short time. To keep such phenomenon to the minimum limits have been introduced for the impact of load variations to the public mains supply network.
Standard reference: IEC/EN 61000-3-3, IEC/EN 61000-3-11

Additional Phenomena - EMC in Vehicles
Apart from the basic phenomena as described here above a wide range of additional requirements can be found for special electrical and electronic systems such as vehicles. These requirements are based on the fact that within a vehicles supply system a large number of sub-systems and components are installed generating interference and at the same time being exposed to interference. Some of the phenomena that can be found on-board vehicles look similar to the ones that are specified in the basic standards of IEC. Some are specific for thes systems.

Many vehicle manufacturers have set up their own EMC requirements for both conducted and radiated immunity and emission testing. These requirements supersede the national and international standards existing for EMC testing on vehicles (e.g. ISO7637, SAE J1113, JASO).

電磁(ci)幹擾現(xian)象
根(gen)據電磁(ci)幹擾的(de)耦合(he)類(lei)型，這(zhe)種(zhong)現(xian)象(xiang)被(bei)分成兩(liang)個不(bu)同的組。如果幹擾信號是空氣(qi)傳(chuan)播(bo)的，可(ke)以(yi)說(shuo)是(shi)輻(fu)射幹擾，而(er)當幹擾信號是帶線(xian)的(de)時，則說(shuo)傳(chuan)導幹擾。

耦合(he)輻(fu)射的(de)地方
固定(ding)和(he)非(fei)平穩無(wu)線(xian)電發(fa)射機（電場）
固定(ding)大功(gong)率無線電發(fa)射機和(he)非(fei)平穩的(de)對講機或移(yi)動通信設備(bei)立(li)即系(xi)統或(huo)設備(bei)附近(jin)操作(zuo)導致(zhi)不(bu)受控(kong)制的電磁(ci)輻射為脆弱的(de)電子(zi)設備(bei)。
參數(shu)：窄(zhai)帶，連(lian)續(xu)電磁(ci)幹擾（調制）。
參考標(biao)準(zhun)：IEC / EN 61000-4-3

高(gao)壓(ya)電源(yuan)傳(chuan)輸(shu)線（磁場）
在這(zhe)些(xie)線(xian)附近(jin)，可(ke)以(yi)產生(sheng)高(gao)磁(ci)場並(bing)耦合(he)到其(qi)他(ta)電子(zi)或電氣(qi)系統中。
參數：16 2 / 3hz或50／60Hz頻帶窄，連(lian)續(xu)的(de)電磁(ci)幹擾
參(can)考標(biao)準(zhun)：IEC / EN 61000-4-8

間接閃電效(xiao)應（脈沖磁場）
高(gao)壓(ya)高(gao)壓(ya)配(pei)電系(xi)統的雷(lei)擊引起(qi)了(le)高(gao)電壓(ya)的(de)電磁(ci)場，它能在(zai)任何(he)低壓(ya)配(pei)電系(xi)統，如電力(li)系統中引起(qi)感應電壓(ya)。此(ci)外(wai)，由(you)於布線(xian)的(de)廣泛(fan)分(fen)布，電信網絡也(ye)受(shou)到間(jian)接(jie)閃電效(xiao)應的威脅(xie)。
參(can)數(shu)：電壓(ya)伏數範(fan)圍(wei)內，目(mu)前有(you)數(shu)百安(an)培(pei)範(fan)圍(wei)，在(zai)微秒範(fan)圍(wei)內的高(gao)能脈沖上升(sheng)時間(jian)。
參(can)考標(biao)準(zhun)：IEC / EN 61000-4-9

耦合(he)在(zai)傳導的地方
感應負載開關(guan)導致(zhi)電快(kuai)速瞬(shun)變（猝發(fa)）
由(you)於開關(guan)從非(fei)導電到*導電狀(zhuang)態的(de)突(tu)然變化而引(yin)起(qi)的電壓(ya)和(he)電流的(de)快(kuai)速變化，在鄰(lin)近地(di)區產生電磁(ci)影響，例(li)如在機械分(fen)離(li)觸點(dian)上切(qie)換感應負載，在它(ta)們(men)分(fen)開(kai)之(zhi)前發(fa)生(sheng)電弧(hu)。
參數：寬(kuan)帶脈沖幹擾，對幾納(na)秒脈沖的上(shang)升時(shi)間(jian)，小(xiao)的能量(liang)含(han)量(liang)和(he)高(gao)重(zhong)復率。
參考標(biao)準(zhun)：IEC / EN 61000-4-4

電源(yuan)系(xi)統中開關(guan)感性(xing)負載或電容(rong)性(xing)負載
在低壓(ya)電源(yuan)系(xi)統中切(qie)換重(zhong)感性(xing)或(huo)容性(xing)負載，會(hui)引起(qi)高(gao)能量(liang)和(he)高(gao)電壓(ya)的(de)瞬(shun)變，這取(qu)決於安(an)裝類別(bie)。
參數(shu)：電壓(ya)有(you)的(de)高(gao)達(da)幾十(shi)千(qian)伏的範(fan)圍(wei)內，電流安(an)培(pei)數(shu)公斤的(de)壹(yi)些(xie)範(fan)圍(wei)，在(zai)微秒範(fan)圍(wei)內的高(gao)能脈沖上升(sheng)時間(jian)和(he)持續(xu)時(shi)間(jian)。
參(can)考標(biao)準(zhun)：IEC / EN 61000-4-5

大氣放(fang)電，如閃電
高(gao)壓(ya)配(pei)電系(xi)統的雷(lei)擊導致(zhi)低壓(ya)電網(wang)的瞬變。通過耦合(he)，這(zhe)些(xie)瞬(shun)變也(ye)可(ke)以(yi)在數(shu)據總線系統(tong)、I/O線(xian)和(he)工業(ye)區(qu)的任(ren)何布線中檢測(ce)到。
參(can)數(shu)：電壓(ya)伏數範(fan)圍(wei)內，電流安(an)培(pei)數(shu)公斤的(de)壹(yi)些(xie)範(fan)圍(wei)，在(zai)微秒範(fan)圍(wei)內的高(gao)能脈沖上升(sheng)時間(jian)。
參(can)考標(biao)準(zhun)：IEC / EN 61000-4-5

電源(yuan)故(gu)障(zhang)
電壓(ya)驟(zhou)降(jiang)和(he)短(duan)時(shi)中斷(duan)是由(you)網絡故障(zhang)、裝置(zhi)故(gu)障(zhang)或(huo)突(tu)然大負荷變化引起(qi)的。在(zai)某些(xie)情(qing)況(kuang)下(xia)，可(ke)能發(fa)生(sheng)兩(liang)次(ci)或多次(ci)連(lian)續(xu)的(de)驟(zhou)降(jiang)或中斷(duan)。電壓(ya)變化是由(you)於不斷(duan)變化的負載連(lian)接(jie)到電源(yuan)供(gong)應網絡(luo)引(yin)起(qi)的。
參(can)數：這(zhe)些(xie)現(xian)象(xiang)本質上(shang)是(shi)隨機的，可(ke)以(yi)用額(e)定電壓(ya)和(he)持續(xu)時(shi)間(jian)的(de)偏差(cha)來(lai)表(biao)征(zheng)。
參(can)考(kao)標(biao)準(zhun)：IEC / EN 61000-4-11

靜電放(fang)電
靜(jing)電放(fang)電發(fa)生(sheng)在兩(liang)個物(wu)體之間的靜(jing)電電場超過(guo)它(ta)們(men)之(zhi)間(jian)的(de)空(kong)氣的介電強(qiang)度(du)時。放(fang)電是(shi)壹(yi)個復雜的事(shi)件，包(bao)括(kuo)在(zai)放(fang)電點(dian)的局部電荷轉移(yi)，涉及(ji)對象之(zhi)間的(de)電磁(ci)近場耦合(he)，接(jie)收物(wu)體的感應電流，從帶電物(wu)體和(he)放(fang)電電弧(hu)發(fa)射電磁(ci)能量(liang)。所(suo)有這些(xie)現(xian)象(xiang)都(dou)會(hui)導致(zhi)故(gu)障(zhang)，在(zai)某些(xie)情(qing)況(kuang)下(xia)也(ye)會(hui)損壞(huai)電子(zi)設備(bei)。
參數(shu)：主(zhu)要(yao)作用是通過電流產(chan)生(sheng)的（小(xiao)於100A）和(he)電壓(ya)（＜30kV）上(shang)升(sheng)時間(jian)在(zai)納秒甚(shen)至(zhi)皮秒(miao)範(fan)圍(wei)。
標(biao)準(zhun)：參照IEC/EN 61000-4-2

射頻場引起(qi)的傳(chuan)導騷擾
傳導無線電頻率幹擾來(lai)自(zi)預(yu)期的(de)射頻發(fa)射機影響(xiang)電纜(lan)，如電力(li)供應線、信號線或電氣(qi)或電子(zi)系統不同(tong)部(bu)分(fen)之(zhi)間的地(di)線(xian)連(lian)接(jie)。
參數：幹擾信號是壹(yi)個振幅(fu)調制或脈沖調制信號，通常在(zai)9kHz和(he)80MHz的頻率之間的頻率範(fan)圍(wei)，有(you)時擴(kuo)展(zhan)230 MHZ。
參考標(biao)準(zhun)：IEC / EN 61000-4-6

諧(xie)波電流發(fa)射
隨著(zhe)越來(lai)越(yue)多的(de)電子(zi)電源(yuan)應用於廣泛(fan)的(de)產品，限制諧(xie)波電流發(fa)射的(de)目(mu)標(biao)變得(de)越(yue)來越重要(yao)。由(you)於諧(xie)波電流對配電網(wang)基礎設施(shi)造成不必要(yao)的負荷，使(shi)配電網(wang)的諧(xie)波電流降(jiang)到相(xiang)當低的(de)水(shui)平(ping)是(shi)電力(li)企業的壹(yi)個特殊利(li)益(yi)。這又(you)可(ke)能影(ying)響電源(yuan)的(de)質量(liang)和(he)可(ke)靠(kao)性(xing)。
參(can)數：諧(xie)波電流測(ce)量(liang)到基(ji)波的第(di)四十(shi)諧(xie)波。每(mei)個(ge)諧(xie)波的限制取(qu)決於產品的(de)類(lei)型(xing)。
參考標(biao)準(zhun)：IEC / EN 61000-3-2標(biao)準(zhun)，IEC / EN 61000-3-12

電壓(ya)變化，電壓(ya)波動和(he)閃變
在產品的(de)整(zheng)個工作(zuo)周(zhou)期(qi)內，可(ke)能突(tu)然發(fa)生(sheng)電壓(ya)變化、電壓(ya)波動或閃變。這可(ke)能會(hui)影響電源(yuan)供(gong)電電壓(ya)的(de)質量(liang)。閃爍可(ke)以(yi)在視(shi)覺(jiao)上(shang)被(bei)識別(bie)，因(yin)為燈的(de)照明(ming)強(qiang)度(du)即使(shi)在很短(duan)的(de)時(shi)間(jian)內也(ye)會(hui)顯著下(xia)降。為了(le)使(shi)負荷變化對公共(gong)供(gong)電網(wang)絡的影響(xiang)，必(bi)須(xu)將這(zhe)種現(xian)象保持在(zai)zui低限度(du)。
參考(kao)標(biao)準(zhun)：IEC / EN 61000-3-3，IEC / EN 61000-3-11

附加(jia)現(xian)象-車輛(liang)電磁(ci)兼(jian)容性(xing)
除了(le)如上所(suo)述的(de)基(ji)本(ben)現(xian)象外(wai)，對於特殊的電氣(qi)和(he)電子(zi)系統，如車輛(liang)，也(ye)可(ke)找(zhao)到廣泛(fan)的(de)附加(jia)要(yao)求(qiu)。這(zhe)些(xie)要(yao)求(qiu)基(ji)於這樣(yang)壹(yi)個事(shi)實(shi)：在車輛(liang)供應系統(tong)中，安(an)裝了(le)大量(liang)的(de)子系統和(he)組件，產生幹擾，同(tong)時又(you)受到幹擾。在(zai)車載車輛(liang)上發(fa)現(xian)的壹(yi)些(xie)現(xian)象(xiang)與(yu)IEC標(biao)準(zhun)中所規定的(de)類(lei)似(si)。有(you)些(xie)是(shi)專(zhuan)為這些(xie)系(xi)統(tong)。

許多汽(qi)車制造商(shang)已(yi)經(jing)建(jian)立(li)了(le)自(zi)己的EMC要(yao)求(qiu)進行(xing)傳(chuan)導和(he)輻射免(mian)疫(yi)力(li)和(he)排放(fang)測(ce)試(shi)。這些(xie)要(yao)求(qiu)取(qu)代(dai)現(xian)有(you)的(de)國家(jia)標(biao)準(zhun)和(he)標(biao)準(zhun)EMC測(ce)試(shi)車輛(liang)（如ISO7637，SAE j1113，JASO）。