Converter for outputting reactive power, and method for controlling said converter

Abstract

A converter outputs reactive power and has three phase branches connected to a phase of an alternating voltage source. Each of the phase branches has a phase module with a series circuit containing two-pole sub modules. A voltage which is dropped across each phase module corresponds to the sum of the voltages which are dropped across the sub modules. The first and the third phase branch are electrically connected to one another by a magnetically coupled throttle pair. A control device controls phase module currents. The control device contains current controllers which are associated with the phase modules, a decoupling unit for decoupling control differences by a computational during control of the phase module currents, a coupling unit for correcting the decoupled computational actuating variables in accordance with the magnetic coupling of the first throttle pair to obtain corrected actuating voltages, and a control unit for driving the sub modules.