Discrete-time H∞ control of PWM inverters: Experimental results complying with IEC 62040-3

This paper aims on the design and experimental validation of a discrete-time H_∞ control for single phase PWM inverters with linear and nonlinear loads, providing results complying with IEC 62040-3 Standard for uninterruptible power supplies. This compliance ensures sinusoidal voltages of high quality for critical loads. The H_∞ control used here is designed by means of linear matrix inequality conditions including constraints on the norm of the control signal, in order to ensure high performance with a feasible action of control, avoiding saturation and high spent of energy from the actuator. Additionally, the controller is implemented in a digital signal processor under constraints as delay in the application of the control signal and limitations on precision and dynamic range of data representation. The control action is a linear combination of the plant states and the states of a controller based on the internal model principle, allowing to track sinusoidal reference signals in the presence of loads with harmonics. The main contribution of the paper is the experimental implementation of this control technique taking into account all the above constraints and producing results complying with IEC 62040-3 Standard.