Estimation of Inductance Derivative for Force Control of Linear Switched Reluctance Actuator

This paper presents an inductance derivative estimation method of linear switched reluctance actuator (LSRA) employing tracking-differentiating technology. The inductance of LSRA is highly nonlinear and varies with phase current and translator position. To achieve direct force control, the derivative of inductance must be estimated to generate required phase currents. The inductance profile of LSRA is obtained from finite element analysis calculation. Tracking differentiator is introduced to track the inductance and its derivative for further control purpose. A simple Proportional-Integral control with compensation unit using the estimated inductance derivative is used to examine the effectiveness of the estimation of inductance derivative.