SOLAR POWER PLANT, METHOD OF CONTROLLING A SOLAR POWER PLANT AND A DC/DC CONVERSION SYSTEM

摘要

A DC power conversion system, a solar power plant and a method of controlling a solar power plant are provided. The DC power conversion system is adapted for converting low voltage DC power from a plurality of DC power sources (2a-n) to a high voltage DC power transmission link. The DC power conversion system comprises a set of first DC/DC converters (4a-n), a medium voltage DC grid (5) and a second DC/DC converter (6) that comprises a high voltage DC output (8). Each DC/DC converter (4a-n) of the set of first DC/DC converters (4a-n) comprises a low voltage DC input (3a-n) adapted for connection to an array (2a-n) of low voltage DC power sources. The medium voltage DC grid (5) connects the set of first DC/DC converters (4a) to the second DC/DC converter (6). The solar power plant (1) comprises a plurality of photovoltaic modules as DC power sources and the DC power conversion system, wherein the photovoltaic modules (PV1, PV2, PVj) are arranged in a plurality of arrays (2a-n), and each array (2a-n) is arranged to feed DC power to a respective input (3a-n) of the low voltage inputs (3a-n) of the DC power conversion system. The method comprises controlling a power transfer from the arrays (2a-n) of interconnected photovoltaic modules (PV1, PV2, PVj), to a high voltage DC connection (8). The method comprises a first step of converting (32), wherein DC power supplied from each array (2a-n) is converted into DC power at a medium voltage DC level, which conversion includes performing a voltage and power control of each array (2a-n), and a second step of converting (34), wherein the medium voltage DC power is converted into DC power at a high voltage DC output (8) to a high voltage DC transmission link.