Controlled Voltage Source with Pulse Width Modulation

The purpose of this paper is an analysis of the dynamic properties of a controlled DC voltage source with PWM. The PWM controls are used in modern power electronic drivers for controlling the voltage, current, or both. The investigation procedure includes a mathematical description of the control system, digital modeling, and prototype creation. The mathematical description is based on the difference equations, which consider the discrete character of PWM signals. One way of analysis is receiving mathematical formulas of a nonlinear difference equation and solving this result using MATLAB. The mathematical formulas can be obtained only for the control system's first and secondary order. The paper considered another way of describing of control system with PWM. In this case, there are no limits on the order of the differential equation. For example, a first-order voltage control system is discussed. Analyses show that in the control system, different modes of operation depend on the gain. The prototype of the controlled voltage source is realized on the base of uncontrolled voltage sources 36V and 10A, Arduino microcontroller, and H bridge PWM driver. The output signal of the Arduino microcontroller is pulse width modulated. The prototype test shows the output mode operation like in the digital model.