Regenerative Braking Performance Analysis of a Thyristor-Chopper Controlled DC Series Motor

This paper presents a comprehensive analysis which predicts the performance of a thyristor-chopper controlled dc series motor during regenerative braking operation. The analysis takes into account all the possible modes of operation during this type of braking, the nonlinearity of the magnetization characteristics including the variation of the field inductance, and the effect of the commutating capacitor in the chopper circuit on the braking performance. It is shown from the computed results that above a critical speed, the value of the commutating capacitor sets a maximum value of mark/space ratio of the chopper regulator beyond which the regenerative braking operation fails. Typical test results on a practical system are shown to agree with the computed results.