A CHOPPER WITH A CONTROL SYSTEM BASED ON A DIGITAL PROCESSOR
A chopper with a digital signal processor in the forward circuit of a closed one-dimensional control system is investigated using the MATLAB system. The considered duty ratio of the chopper consists of two phases: the phase of the energy pumping and the discharge phase to the load. During the pumping phase, the key element is closed, and conducts a current that flows from the power supply to the load through the inductance, at which time energy storage takes place. Therefore, when the key breaks at the end of the pump phase, the current, supported by the inductive element, is forced to close the discharge diode. It is shown that the change in the current, during the pump phase and the discharge phase occurs according to linear laws. To extract a constant current component, a classic Г-shaped LC filter circuit is used. A virtual chopper model is developed. Open and closed transfer functions of the chopper are constructed. The method of choosing the feedback coefficient, considered in this paper, is of an interactive nature.To evaluate the dynamic properties of the system, the response to a single step effect is considered. For the final calculation of the output voltage setting time, it is necessary to construct a transient response using MATLAB. The settling time of the chopper output voltage is calculated. It is shown how the digital processor eliminates a static error and significantly improves the transient response of the chopper. Analyzing the oscillograms of the output voltage, we can conclude that a digital signal processor can be used to stabilize the voltage of the chopper.