| Title |
Low-cost Shunt-based Current Sensing Technique for DC Component Reduction in Output Current of Single-phase Grid-connected Photovoltaic Inverters |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2016.30.5.046 |
| Keywords |
DC Component ; Photovoltaic Inverter ; Offset ; Thermal Drift ; Shunt Resistor |
| Abstract |
An unwanted DC component in output current of single-phase grid-connected photovoltaic inverters is strictly limited by regulations. The output DC current component is mainly due to the fact that the offset in a current sensor used to measure the output current drifts with temperature. To solve such a thermal drift problem, several solutions compensating the offset error by detecting the output DC current component, and a shunt-based current sensing technique measuring the voltage of a shunt resistor inserted in the inverter output by isolation have been proposed. In this paper, in order to solve the isolation issue causing almost all of the cost in the conventional shunt-based current sensing technique, a non-isolated shunt-based current sensing technique by changing the position of the shunt resistor is proposed. The validity of the proposed method is verified by experimental results of a 3kW prototype. |