本文件旨在为额定功率超过500 kVA的液浸式电力变压器和并联电抗器的降噪选择合适的外部方法提供指南。本文描述了许多降噪程序，这些程序目前可用于在变压器和并联电抗器装置中实现不同程度的降噪。作为背景信息，本文件还将讨论变压器和电抗器内的噪声源。

This document is intended to provide guidelines for selecting suitable external methods for noise reduction in liquid-immersed power transformers and shunt reactors rated over 500 kVA. Many noise abatement procedures are described that are presently available for achieving various levels of noise reductions in transformer and shunt reactor installations. For background information, this document will also discuss the noise producing sources within the transformers and reactors.