Design and Implementation of an Energy Feedback Digital Device Used in Elevator

Reducing energy consumption is very important in solving the problem of energy crisis and environmental problem. Usually, an elevator with a diode rectifier wastes regenerated power from its electric motor as heat on breaking resistors. This paper proposes an energy feedback digital system used in an elevator of 18.5 kW which is capable of recycling the regenerated power: obtaining near-unity power factor, sinusoid output current, and low total harmonic distortion in generator-operation state. It has reliable protection circuits and cute man-machine interface, and the feedback point of the dc voltage can be set arbitrarily in a certain extent, meeting the large-range variation of power system voltage. Field operation results showed good performance and energy-saving effect.