Regenerative DC drive system

The energy during braking, for the single motor or multimotor (with common DC bus) DC drive systems, can be regenerated into the AC power line or can be used by the other drive systems. The proposed regenerative DC drive system consists of a series active power rectifier and a four quadrants DC-DC power converter connected to the DC machine. The quality of the regenerated energy is an important issue. The control of the voltage source converter is based on the minor current loop in a synchronous rotating-frame with a feedforward load current component added at the reference, completed with the dc voltage control loop in a cascaded manner. Using the synchronous rotating frame, the active and reactive power can be controlled independently by proportional-integral (PI) current controllers that ensures zero-steady state error. The cascaded regulated loops (current and speed) have been involved in the load side. By applying the power balance control the regenerative drive system provides sinusoidal input current, unity power factor, bi-directional power flow, small (up to 5%) ripple in the dc-link voltage in any operated conditions, disturbance compensation capability, and fast control response. The performances of the regenerative drive system (in motoring and regenerating operation modes) have been shown through the simulation results.