VOLTAGE CONTROL IN A DIRECT CURRENT POWER SYSTEM

摘要

A converter station (12) in a direct current power system (10) connected between an alternating current power line (30) and a direct current power line (14) comprises a transformer (18), a converter (20) equipped with converter valves of which at least a first set is connected to the transformer and a control unit (22) controlling the converter station for providing a DC voltage (VDC1) at one end of the direct current power line for contributing to the forming of a voltage difference together with another DC voltage (VDC2) generated by a further converter station (16) at an opposite end of the direct current power line for enabling a feeding of power over the direct current power line. The control unit controls the converter to provide a DC voltage through using firing angle control of the converter valves connected to the transformer.