Stability Analysis and Oscillation Suppression Control in Open Loop Control of Induction Motor

Abstract

Under light-load and low-speed conditions, the V/F open-loop control of induction motors triggers continuous oscillation, causing motor speed fluctuations, loss of control, and even motor overcurrent, potentially causing damage to the power module in severe cases. This paper proposes a method to suppress oscillation in the open loop control of induction motors. Firstly, a detailed study was performed by establishing a state equation of induction motors and investigating the impact of parameters such as speed and slip on the stability of the open loop control. Based on a comprehensive review of existing methods and simulation experiments, a new oscillation detection and suppression method was proposed. Secondly, a further study was conducted to reveal the influence of parameters of the suppression method on system stability through small-signal modeling. Finally, simulation experiments were conducted to verify the proposed method. The results show that the oscillation suppression method is highly effective across a range of stator resistance, stator leakage inductance, rotor resistance, and rotor leakage inductance varying from 0.25 to 4 times, as well as control parameters varying from 0.5 to 2 times.

Keywords

• induction motor
• v/f open-loop control
• stability analysis
• oscillation suppression