PROJECT TITLE :

Synchronverters with better stability due to virtual inductors, virtual capacitors and anti-windup - 2017

ABSTRACT:

Synchronverters are inverters that mimic the behavior of synchronous generators. During this paper, we tend to propose 5 modifications to the synchronverter algorithm from the paper “Synchronverters: Inverters that mimic synchronous generators,” (IEEE Trans. Ind. Electron., vol. 58, no. 4, pp. 1259-1267, Apr. 201one), to boost its stability and performance. These modifications are implemented in software and do not require any changes within the inverter hardware. The first 2 modifications concern the control of the virtual field current within the synchronverter so that it's additional robust to faults. We prove the steadiness of the grid-connected synchronverter with this improved field current controller. The third modification is to extend the effective size of the filter inductors just about. This is motivated using results from the soundness analysis of a continuing field current synchronous generator connected to an ac power grid and additionally by sensible issues. Simulations and experiments show that this ends up in a abundant higher response to changes in grid frequency, voltage, or to imbalance within the grid. The fourth modification is to alter the formula for the (virtual) nominal active mechanical torque to take under consideration the (virtual) losses in the output impedance of the converter. This makes the tracking of the required active power a lot of a lot of accurate. The fifth modification is to introduce virtual capacitors in series with the inverter outputs to filter spurious dc parts from the current provided to the grid.