Synthesis of a robust control system for two-mass electric drive by H∞-theory

Abstract

The practice of designing and operating control systems for industrial facilities has shown that systems synthesized according to the criteria of modular and symmetric optima, as well as by quadratic quality criteria, are sensitive to changes in the parameters of the controlled object, incoming characteristics, disturbing influences, the structure and parameters of the object model changing, which used in control loops. Such systems can lose optimality as well as productivity, if information about the object and operating environment is known with some probability or uncertainty. For an industrial electric drive, changes in load torque, moment of inertia of rotating parts, supply voltage and environmental characteristics (temperature, vibration) are especially significant. These changes affect both the mechanical characteristics rigidity and the transients’ quality.
 Robust control systems provide a required quality of work when changing the characteristics of impacts and instability of the control object parameters in a wide range. In the presence of uncertainties, a robust controller provides robust stability and quality for all admissible uncertainties.
 The synthesis of robust control systems with an H∞-speed controller of a two-mass electric drive by methods of H∞-theory is presented in order to prove the possibility of using algorithms for a given stabilization and speed control, as well as providing the necessary degree of sensitivity to parametric and coordinate disturbances acting on the control object. Application of the method of robust controllers’ synthesis taking into account the requirements for the quality of a controlled coordinate transient processes in the control system. The analysis of the operation of a synthesized robust system with an H∞-speed controller using digital modeling on mathematical models in the MATLAB / Simulink environment is carried out. The possibility of the speed independent control, the steady-state error and the nature of the transient processes of the controlled coordinate in the synthesized electric drive control system is shown.