Power conversion device and refrigeration cycle device

This power conversion device is provided with: a power conversion unit that converts the voltage and frequency of power supplied from a power source via a power line and supplies the converted power to a load; and an active noise canceller that detects noise flowing through the power supply line and outputs a noise cancellation signal for attenuating the noise to the power supply line, the active noise canceller comprising: a first substrate on which a heavy current system circuit for detecting the noise is mounted; and a second substrate on which a weak current system circuit for generating a noise cancelling signal is mounted. 电力转换装置具备：电力转换部，转换从电源经由电源线供给的电力的电压以及频率并供给到负载；和有源噪声消除器，检测在电源线中流动的噪声，并对电源线输出使噪声衰减的噪声消除信号，有源噪声消除器具有：第1基板，搭载有检测噪声的强电系统电路；和第2基板，搭载有生成噪声消除信号的弱电系统电路。