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The stability of a single machine infinite bus system with a static var compensator is proposed by an improved adaptive backstepping algorithm, which includes error compensation, sliding mode control and a κ -class function. First, storage functions of the control system are constructed based on modified adaptive backstepping sliding mode control and Lyapunov methods. Then, adaptive backstepping method is used to obtain nonlinear controller and parameter adaptation rate for static var compensator system. The results of simulation show that the improved adaptive backstepping sliding mode variable control based on error compensation is effective. Finally, we get a conclusion that the improved method differs from the traditional adaptive backstepping method. The improved adaptive backstepping sliding mode variable control based on error compensation method preserves effective non-linearities and real-time estimation of parameters, and this method provides effective stability and convergence.

We present a three dimensional (3D) micro integral imaging display system with extended depth of focus by using a polarized bifocal liquid crystal lens. This lens and other optical components are combined as the relay optical element. The focal length of the relay optical element can be controlled to project an elemental image array in multiple positions with various lenslet image planes, by applying different voltages to the liquid crystal lens. The depth of focus of the proposed system can therefore be extended. The feasibility of our proposed system is experimentally demonstrated. In our experiments, the depth of focus of the display system is extended from 3.82 to 109.43 mm.

The secondary voltage control problem of inverter-based islanded microgrid (MG) is proposed in this paper. First, the dynamics of the distributed generation (DG) with primary control is analyzed and modeled. Then, an RBF-neural-network (RBF-NN) sliding-mode controller is designed to eliminate the voltage deviation caused by primary control. The output voltage of all DGs can restore to a reference value and remains stable. Finally, taking an MG consisting of four DGs as an example, the experimental results validate the designed secondary control strategy. INDEX TERMS Islanded microgrids, secondary voltage control, distributed, RBF-neural-network sliding-mode control.

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