Acoustic aspects of dry-type air-core reactors—specification, design, testing, field measurements

Abstract

The demand for dry-type air-core reactors (henceforth, referred to as “reactor(s)”) is growing because of the increasing use of power electronics in transmission and distribution grids and because of the implications of dispersed energy generation. For reactors used in power electronic grid applications such as High Voltage Direct Current (HVDC) and Flexible Alternating Current Transmission Systems (FACTS) applications, the content of the harmonic currents is significant. For other applications such as Filter Reactors, Detuning Reactors and Reactors for Mechanically Switched Capacitors with Damping Network (MSCDN), the harmonic currents can also be significant. This paper presents the correct method for specifying these harmonic currents and the possible consequences of specifying them incorrectly. Additionally, this paper discusses new and innovative solutions for mitigating the sound emission from reactors. For the purpose of sound planning, measuring the sound level of a reactor is equally as important as designing the reactor. Therefore, the last two sections of this paper will present and discuss the modern methods for measuring the sound level of reactors in the test lab and in the substation.