Title :
An energy-based control for an n-H-bridges multilevel active rectifier
Author :
Aquila, Antonio Dell ; Liserre, Marco ; Monopoli, Vito Giuseppe ; Rotondo, Paola
Author_Institution :
Dept. of Electr. & Electron. Eng., Politecnico di Bari, Italy
fDate :
6/1/2005 12:00:00 AM
Abstract :
This paper deals with the control of a multilevel n-H-bridges front-end rectifier. This topology allows n distinct dc buses to be fed by the same ac source offering a high loading flexibility suitable for traction applications as well as for industrial automation plants. However, this flexibility can lead the system to instability if the dc buses operate at different voltage levels and with unbalanced loads. Thus, linear controllers, designed on the basis of the small-signal linearization, are not effective any longer and stability can not be ensured as large-signal disturbances occur. The use of a passivity-based control (PBC) designed via energy considerations and without small-signal linearization properly fits stability problems related to this type of converter. The system has been split into n subsystems via energy considerations in order to achieve the separate control of each dc bus and its stability in case of load changes or disturbances generated by other buses. Then, a set of n passivity-based controllers (one for each subsystem) is adopted: the controllers are linked using dynamical parameters computed through energy balance equations. Hence, the system dc buses are independent and stable as experimental results demonstrate.
Keywords :
bridge circuits; circuit stability; digital control; industrial control; power convertors; rectifying circuits; traction power supplies; AC source; DC buses; PBC; digital control; dynamical parameter; energy balance equation; energy-based control; front-end rectifier; industrial automation plant; linear controller; n-H-bridges multilevel active rectifier; passivity-based control; small-signal linearization; traction application; unbalanced load; Automatic control; Automation; Control systems; DC generators; Electrical equipment industry; Lead; Rectifiers; Stability; Topology; Voltage; Digital control; multilevel systems; rectifiers;
Journal_Title :
Industrial Electronics, IEEE Transactions on
DOI :
10.1109/TIE.2005.843971