Deere & Company
System and method for frequency adjustment of parallel inverters coupled to a grid power source

Abstract:

A first inverter has a set of first output phases coupled to a grid voltage source. A second inverter has a set of second output phases coupled to the grid voltage source. A phase measurement device is adapted to measure at least one reference phase of the grid voltage source at a reference phase point. An electronic data processor is configured to: determine an observed phase difference between the reference phase point and an observed position sample of a pulse-width-modulation carrier signal of the first inverter, the second inverter, or each parallel-coupled inverter; determine a target phase difference between the reference phase point and target position sample of the pulse-width-modulation carrier signal; determine a frequency adjustment to the pulse-width-modulation carrier signal of the first inverter, the second inverter, or all parallel-coupled inverters, based on a difference between the observed phase difference and the target phase difference.