Analysis of RL-circuit supply by voltage with sinus or square waveform

The serial connection of resistor R and inductance L is a basic electronic circuit. It's the same is main circuit in industrial power consumers: electric motors, induction furnaces, welding devices and other electrical consumers. The ratio of the values on resistor and inductance in the serial circuit determines the amount of active energy that the power source delivers to the consumer. From the power point of view, the amount of this energy should be as high as possible, ie the circuit should work with a good power factor and a good efficiency. When the RL-circuit is supplay by sinusoidal-prostoperiodic voltage the amount of active energy is determined by the values on effective voltage and current in the circuit, and the power factor determined by the phase difference between the voltage and current. In the literature there is detail information for the work of the serial RL-circuit supplay by sinusoidal voltage. The situation is quite different when the RL-circuit is supplay by voltage with square waveform. The amount of delivered energy then depends not only on the phase difference between the voltage and the current, but also and from the harmonic distortion of the magnitudes of the voltage and current. Such RL-circuits, supplay by voltage with with square waveform are found in all power converters: speed regulators in directional and alternating motor, induction heating devices, voltage regulators for different RL-consumers. In the literature which deals with this matter, there is room for clarification of nature of the behavior on RL-circuit supplay by voltage with square waveform. In this paper first is made a mathematical calculation of power when the serial RL-circuit is supplay by voltage with sinus waveform and when it is supplay by voltage with square waveform. Also are give the results obtained with simulations in the PowerSim software package. In finally are given the experimental results of this circuit. An analysis of the obtained results and a comparison of the performance of the RL-circuit supplay by the two analyzed waveforms, sinusoidal and quadratic are made. Keywords: RL-circuit, power factor, efficiency. Field: Technical and technological sciences