Derivation Of DC Servo Driver Current Loop Model

Cello products developed by Elmo is a high-performance and high-power DC servo driver, which can operate in position, speed and current mode. In the current mode, the driver can self adjust the parameters of the current loop of the permanent magnet synchronous motor, and obtain higher current loop bandwidth and better current response. In order to explore the self-tuning mechanism of the current loop of Cello products, starting from the establishment of the current loop model, the bode diagram obtained by the upper computer of Elmo products is analyzed, and its transfer function is deduced, so that the same current loop model of Elmo product is obtained. According to the model obtained from the analysis, simulation experiments are carried out and verified on several models of motors. The experimental results are highly consistent with the modeling results of Elmo products.