Implementation of a DSP‐based speed‐sensorless adaptive control for permanent‐magnet synchronous motor drives with uncertain parameters using linear matrix inequality approach

Abstract

Abstract This paper presents a novel speed sensorless adaptive control scheme for the uncertain permanent‐magnet synchronous motor (PMSM) drive system using a linear matrix equalities approach with a digital signal processing (DSP) chip. The dynamic model of the PMSM drive with eight error states based on the structure of speed estimator, speed and current controllers is developed. The speed controller, current controller and rotor speed and position estimators are considered simultaneously and designed together. In addition, a three‐parameter observer is also designed and the adaptive control law is derived in the light of Lyapunov stability theorem. The objective of this study is to determine the two estimation gains and the six control gains such that the closed‐loop system is stable. The stability condition of the system can be characterized in terms of some linear matrix inequalities (LMIs). The LMIs problem can be efficiently solved with the help of MATLAB simulation tool. Differently from the conventional proportional‐integral controller, a novel controller with a low‐pass filter instead of a pure integrator is proposed. By a suitable adjustment for a design parameter, the steady‐state error can also be improved. Numerical solutions of the controller and the estimator gains and simulation examples are provided to illustrate the design procedure and corresponding performances. The experimental results by using a TI TMS320F28335 DSP chip with the speed reference 400, 700, 1000 RPM, respectively and sudden change of the reference demonstrate the performance of the proposed control scheme.

Keywords

• AC motor drives
• adaptive control
• linear matrix inequalities
• Matlab
• sensorless machine control