A Novel Design of Analog Signal Power Amplifier Module for Relay Protection Tester

The analog signal power amplifier module is an important component of relay protection tester. As is known, most of the analog signal power amplifier modules employ single output loops to achieve the output accuracy regardless of the output current, which may lead to large capacity, low efficiency and more cost. In order to overcome these deficiencies aforementioned, a novel design for the analog signal power amplifier module is proposed in this paper. This design improves the complementary push-pull current amplification circuit, and adds the logical control loop and the analog switch so that the current amplification circuit can switch different output loops according to the output current, which results in lower capacity, volume and cost, and higher efficiency. Finally, the new analog power amplifier module shows good amplitude-frequency property in the simulation and has ability to meet the relay protection tester demand under different frequency.