Power converters

Abstract

The present invention provides a power converter that can be used to interface a generator that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge electrically connected to the stator of the generator and a network bridge. A dc link is connected between the generator bridge and the network bridge. A filter having network terminals is connected between the network bridge and the supply network. A first controller is provided for controlling the operation of the semiconductor power switching devices of the generator bridge. Similarly, a second controller is provided for controlling the operation of the semiconductor power switching devices of the network bridge. The first controller uses a dc link voltage demand signal VDC_NET* indicative of a desired dc link voltage to control the semiconductor power switching devices of the network bridge to achieve the desired level of dc link voltage that corresponds to the dc link voltage demand signal VDC_NET*. The second controller uses a power demand signal P* indicative of the level of power to be transferred from the dc link to the supply network through the network bridge, and a voltage demand signal VTURB* indicative of the voltage to be achieved at the network terminals of the filter to control the semiconductor power switching devices of the network bridge to achieve the desired levels of power and voltage that correspond to the power and voltage demand signals P* and VTURB*.