Abstract: From learning the mechanism of SADA （solar array drive assembly） microvibration, taking motor ripple torque and friction of slipring into account, a systemic model of the closedloop SADA driven by PMSM （permanent magnet synchronous motor） is established. The coupling dynamical equation between flexible solar cell arrays and motor driver is built. The friction of slipring is modeled by Striebeck effect, whose parameters are identified offline via nonlinear least square. Based on PI control strategy, the feedforward compensation is presented with the estimated value of the identified model. The simulation results show that the modelbased friction compensation can accurately estimate and compensate the friction nonlinearity with high precision and faster system response, by which the accuracy of speed tracking and performance of motor at low velocity are improved.

Key words: microvibration, PMSM, striebeck friction, friction compensation