EMI 電磁干擾

電磁干擾(英文:Electromagnetic Interference,簡稱EMI)是指任何在傳導電磁場伴隨著電壓電流的作用而產生會降低某個裝置、設備或系統的性能,或可能對生物或物質產生不良影響之電磁現象。

電磁干擾也是變頻器驅動系統的一個主要問題。在許多國家,尤其在歐洲,對任何系統可能散發的電磁干擾有嚴格的限制。

 

EN 55022 is a modified derivative of CISPR 22 that applies to information technology equipment (ITE) as defined as any equipment:

– Which has a primary function of either (or a combination of) entry, storage, display, retrieval, transmission, processing, switching or control of data and of telecommunication messages and which may be equipped with one or more terminal ports typically operated for information transfer;
– With a rated supply voltage not exceeding 600 V.

Procedures are given for the measurement of the levels of spurious signals generated by the ITE and limits are specified within the standard for protection of radio services in industrial, commercial or residential environments in the frequency range of 9 kHz to 400 GHz for both class A and class B equipment.

The intention of this publication is to establish uniform requirements for the radio disturbance level of the equipment contained in the scope, to fix limits of disturbance, to describe methods of measurement and to standardize operating conditions and interpretation of results.

Compliance with this standard gives partial presumption of conformity with the European EMC Directive, 2004/108/EC. Most products will also require assessment to the companion standard EN 55024, for immunity to electromagnetic interference and transient phenomenon. Additionally, devices powered via the AC mains, may require additional testing for power line harmonics and power line flicker.

Information Technology Equipment (ITE), as would be tested for EN 55022, includes computer hardware and software, operating systems, web-based information and applications, telephones and other telecommunications products, video equipment and multimedia products, information kiosks, and office products such as photocopiers and fax machines.

 

IEC 61000-6-4: Emission standard for industrial environments applies to electrical and electronic apparatus intended for use in industrial environments as described below. Emission requirements in the frequency range 0 Hz to 400 GHz are covered. No measurement needs to be performed at frequencies where no requirement is specified. This generic EMC emission standard is applicable if no relevant dedicated product or product-family EMC emission standard exists.

IEC 61000-6-4 applies to a apparatus intended to be connected to a power network supplied from a high or medium voltage transformer dedicated to the supply of an installation feeding manufacturing or similar plant, and intended to operate in or in proximity to industrial locations, as described below. This standard applies also to apparatus, which is battery operated and intended to be used in industrial locations.

The environments encompassed by this standard are industrial, both indoor and outdoor. Industrial locations are in addition characterized by the existence of one or more of the following examples: industrial, scientific and medical (ISM) apparatus; heavy inductive or capacitive loads that are frequently switched; high currents and associated magnetic fields.

The object of this standard is to define the emission test requirements for apparatus defined in the scope in relation to continuous and transient, conducted and radiated disturbances. The emission requirements have been selected so as to ensure that disturbances generated by apparatus operating normally in industrial locations do not exceed a level that could prevent other apparatus from operating as intended. Fault conditions of apparatus are not taken into account. Not all disturbance phenomena have been included for testing purposes in this standard but only those considered as relevant for the equipment covered by this standard. These requirements represent essential electromagnetic compatibility emission requirements. Requirements are specified for each port considered.