Dimensionless nomogram approach in the courses of power electronics and electrical drives

One of the traditional difficulties in the courses 'Power Electronics' and 'Electrical Drives' is parameters estimation in the non-linear electronic schemes including inductances, capacitances, resistances as well as diodes and switches. These schemes could be found in equivalent circuits of electric motors and multiple electronic devices that are applicable in power electronics. Taking into account complications to solve non-linear ordinary differential equations (ODE) describing occurring processes and their parameters typical student has a problem to achieve analytical results. Numerous linearization methods were used in the past that was aiming to make things easier and this way to get roughly approximate however analytical solution. Today coarsely estimated results are inacceptable as a rule. Therefore, typical approach in this case is an application of simulation software programs such as PSIM, MATLAB Simulink, WOLFRAM Matematica and others giving excellent opportunity to get accurate answer. However, such numerical results are being extremely truthful aren't capable to allow visible representation of outcomes and this circumstance significantly decrease their value. In mentioned above courses of Power Electronics and Electrical Drives are learned in Ariel University a wide application are obtained methods of numerical nomograms with dimensionless representation of input-output parameters. Dimensionless approach allows significant diminishing of a number of involved variables and this way to simplify calculation. A usage of dimensionless method provides acceptable precision of results with the possibility to represent different parameter's trends in wide range of input conditions. The possible objects of analysis could be for example, output characteristics of DC motors fed by controllable and uncontrollable n-phase rectifiers, resistive rectifier losses and motor's efficiency, and some others. Long time practice of these approaches approved their usefulness, productivity and helpfulness.