Regenerative control of DC drive system

Towards improving the energy usage efficiency of the single motor or multi-motor (with common DC bus) DC drive systems regenerative braking is used; which is an energy recovery mechanism. During braking the energy is regenerated in to the ac power line or can be used by the other power systems. In this paper, a new regenerative braking methodology is proposed for the DC drive system which consists of a series active power rectifier and a four quadrants DC-DC power converter connected to the DC machine. The control of the voltage source converter is based on the minor current loop in a synchronous rotating-frame with a feed forward load current component added at the reference, completed with the dc voltage control loop in a cascaded manner. To ensure zero-steady state error, the active and reactive power are controlled independently by proportional-integral (PI) current controllers using the synchronous rotating frame. The cascaded regulated loops such as current loop and speed loop are included in the load side. By employing the power balance control the regenerative drive system delivers sinusoidal input current, unity power factor, bi-directional power flow, small ripple in the dc-link voltage in any operated conditions, disturbance compensation capability, and fast control response. The simulation results are presented to show the effective performances of the regenerative drive system (in motoring and regenerating operation modes).