IEEE C37.90.2-2004 pdf free.IEEE Standard for Withstand Capability of Relay Systems to Radiated Electromagnetic Interference from Transceivers.
IEEE C37.90.2 defines a required withstand level and establishes a test method to evaluate the susceptibility of protective relays to single-frequency electromagnetic fields in the radio frequency domain, such as those generated by portable or mobile radio transceivers and wireless communication devices. This publication includes test requirements, signal levels, and setups.
1.2 Purpose
The purpose of this standard is to establish a common reference and test procedure for evaluating the performance of equipment used for power system protection when subject to Radiated Electromagnetic Interference from Transceivers.
2. Definitions
Definitions of relay terms are not included in this standard. Refer to IEEE Std C37. 100TM- 1992, Standard
Definitions for Power Switchgear [B6]’ for definitions of relay terms. These terms are also included in The
Authoritative Dictionary of IEEE Standards Terms, Seventh Edition [B4].
2.1 far field: Region where the power flux density from an antenna approximately obeys an inverse square law of distance.
2.2 frequency band: Continuous range of frequencies extending between two limits.
2.3 polarization: Orientation of the electric field vector of a radiated field.
2.4 shielded enclosure: Screen or solid metal housing designed expressly for the purpose of isolating the internal from the external electromagnetic environment.
3. Test severity level
The rms feld strength prior to modulation shall be 20 V/m. The waveform shall be amplitude modulated witha 1 kHz sine wave. Modulation shall be equal to 80%, with the resulting maximum rms field strength not being less than 35 V/m. The test carrier frequency shall be swept or stepped through the range of 80 MHz to 1000 MHz.
4. Test equipment
The following types of test equipment are recommended. The use of other means of establishing and controlling the field is acceptable providing the required conditions can be verified:
a) Anechoic Chamber: of a size adequate to maintain a uniform field of sufficient dimensions with respect to the equipment under test (EUT). Additional absorbers may be used to damp reflections in chambers, which are not fully lined.
NOTE- Alternative methods of generating electromagnetic fields include TEM cells and stripline circuits,unlined screened rooms, partially lined shielded rooms, and open area test sites. Care should be taken to ensure that the conditions of tests are equivalent to those in the anechoic chamber.
b) Radio Frequency (RF) Signal generator(s) capable of covering the frequency range with capability of an 80% amplitude modulation by a 1 kHz sinewave. If the test carrier is to be swept, the RF signal generator should be capable of achieving a sweep rate of 1.5x 10-5 decades per second.
c) A power amplifier to amplify signal and provide antenna drive to the necessary field level, if signal generator is inadequate.IEEE C37.90.2 pdf download.