| Title |
Implementation of Dual Current Controller and Realtime Power Limiting Algorithm in Grid-connected Inverter during Unbalanced Voltage Conditions |
| Authors |
송승호(Song Seung-Ho) ; 김정재(Kim Jeong-Jae) |
| Keywords |
Dual Current Controller ; Voltage Unbalance ; Inverter Current Limit ; Maximum Power |
| Abstract |
A power limiting algorithm is proposed for stable operation of grid-connected inverter in case of grid voltage unbalance considering the operation limit of inverter. During the voltage unbalance the control performance of Inverter. is degraded and the output power contains 120Hz ripple due to the negative sequence of voltage. In this paper, conventional dual sequence current controller is implemented to solve these problems using separated control of positive and negative sequence. Especially the maximum power limit which guarantees the maximum rated current of the inverter is automatically calculated as the instant grid voltage changes. As soon as the voltage recovers the proposed algorithm can return to the normal power control mode accomplishing low voltage ride through. Proposed algorithm is verifed using PSCAD/EMTDC simulations and tested experimentally at 4.4kW wind turbine simulator set-up. |