IEC 61000-4-7:2019, also known as "Electromagnetic compatibility (EMC) - Part 4-7: Testing and measurement techniques - General guide on harmonics and interharmonics measurements and instrumentation, for power supply systems and equipment connected thereto", is a technical standard published by the International Electrotechnical Commission (IEC).
Understanding Harmonics and Interharmonics
In electrical systems, harmonics refer to the distortion of a waveform caused by the presence of frequencies that are integer multiples of the fundamental frequency. Harmonics can be generated by non-linear loads such as computers, variable speed drives, and fluorescent lighting. Interharmonics, on the other hand, are frequencies that do not have an exact harmonic relationship with the fundamental frequency.
The IEC 61000-4-7:2019 standard provides guidance on how to measure and evaluate harmonics and interharmonics in power supply systems and equipment. It defines the measurement procedures and instruments required for accurate assessment.
Measurement Techniques and Instruments
IEC 61000-4-7:2019 outlines various measurement techniques for both conducted and radiated emissions. Conducted emissions refer to the interference that is conducted through power or signal cables, while radiated emissions are disturbances that are propagated through the air. The standard provides detailed instructions on how to set up the measurement environment and select appropriate instruments for conducting these tests.
Some of the commonly used instruments for measuring harmonics and interharmonics include spectrum analyzers, power quality analyzers, and oscilloscopes. These instruments help to capture and analyze the electrical signals, providing valuable insights into the presence and severity of harmonics and interharmonics.
Benefits of Compliance
Compliance with IEC 61000-4-7:2019 ensures that power supply systems and equipment meet the specified electromagnetic compatibility requirements. By accurately measuring and evaluating harmonics and interharmonics, potential issues such as voltage distortion, overheating of equipment, and disruptions to communication systems can be identified and mitigated.
Frequent testing and compliance with this standard also translates into improved energy efficiency, reduced operational costs, and increased reliability of electrical systems and devices. It enables manufacturers, designers, and users to ensure that their products and installations are environmentally friendly, safe, and compliant with international standards.
Nina She