Efficient robust control of pure sine wave inverters for robotic automation systems

In this paper, an efficient robust control is proposed for the application of pure sine wave inverters in robotic automation systems. The presented efficient robust control exhibits the virtues of finite-time convergent sliding mode control (FTCSMC) together with fractional grey Bernoulli model (FGBM). The distinguishing characteristic of the FTCSMC includes nonexistence of singularities and permits quick convergence of state trajectories towards the equilibrium point in a relatively short period of time. However it is possible for the FTCSMC to incur chattering or steady-state errors if the unknown restrictions of the system are exaggerated or underestimated. The chattering induces the harmonic distortion and delayed dynamic behavior in the pure sine wave inverter output voltage, negatively affecting the stability of the robotic automation system. A mathematically easier and computationally more efficient FGBM for pure sine wave inverters in robotic automation systems is used to overcome the chattering and steady-state errors, providing a high reliability and robust performance. Experimental results illustrate that a DSP-based digitally controlled pure sine wave inverter provides both low harmonic distortion and rapid transient changes in the output voltage subjected to various loading circumstances. Because the proposed efficient robust control offers sound steady state and dynamic response, it will be a useful reference for interested researchers in the field of robotics and industrial automation.