| Abstract |
In grid connected multiple string inverter systems, it is normal to synchronise the output current of each
inverter to the common network voltage. Any current controller deficiencies, which result in low order
harmonics, are also synchronised to the common network voltage. The harmonics produced by individual
converters show a high degree of correlation and tend to be additive. Each controller can be tuned to
achieve a different harmonic profile so that harmonic cancellation can take place in the overall system,
thus reducing the net current total harmonic distortion level. However, inter-inverter communication is
required. A novel technique is presented for producing cancellation of low order harmonics in gridconnected
inverters for photovoltaic systems. A randomised based control in each inverter causes a
different harmonic profile so that harmonic cancellation can take place in the overall system, thus
reducing the net current total harmonic distortion level. |
