Enhanced traction system for trolleybuses, powered from a 600- volt direct current power line

摘要

An electrical system that receives power from an external power source that includes an inverter (U1). The inverter (U1) receives DC power and generates a variable voltage output. First and second current collectors (30, 32) connected to the inverter (U1) and receive the DC input through contact with positive and negative poles of the external power source. A motor (M1) and an internal DC bus (+,-) are connected to the current collectors (30,32). A protection circuit is connected across the internal DC bus (+,-), and protects the inverter (U1) from connection to an input of improper polarity. The protection circuit permits the inverter (U1) to deliver a DC output to the power source during a regenerative braking operation.