Regenerative Braking System and Electrically-Driven Work Vehicle Using Regenerative Braking System

A power regeneration device that converts the power of a main engine DC line connected to a main engine power generator through a rectification circuit to supply the converted power to an accessory DC line connected to an accessory power generator through a rectification circuit includes a plurality of power conversion modules to N configured such that input sections to Na are connected in series. The main engine power generator and a power consumption device are controlled such that a voltage input to the power regeneration device does not exceed a voltage upper limit value Vm and a portion between a positive electrode terminal (+) and a negative electrode terminal (−) of each of the input sections of the power conversion modules to be stopped is short-circuited by a bypass device and the voltage upper limit value Vm is decreased when some of the plurality of power conversion modules to N are stopped. With this configuration, operational continuity can be improved while a device size increase is prevented.