Active Power Saturation for Full-Scale Renewable Power Converters during Voltage Ride Through Operation

Modern grid codes require the injection of positive sequence reactive current during low voltage ride through operation. In addition, it is possible to mitigate others power quality issues during unbalanced voltage sags, but for this should flow negative sequence currents. Therefore, to meet the GC and perform ancillary services, it is necessary to reduce the active power production in order to avoid the converter overcurrent. The aim of this paper is to present a dynamic active power saturation, in accordance with the voltage ride through grid code requirements, which can also be applied to compensate different power quality issues over unbalanced voltage operation. The algorithm is evaluated using computational simulations of a 2(MW) power system converter.

I. Introduction

The high penetration of alternative energy generation, such as wind and photovoltaic, have led the Transmission Systems Operators (TSOs) to develop stricter rules for these systems integration to the electrical mains.