The present invention provides a power converter that can be used to
interface a generator (4) 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 (10) electrically connected to the stator of
the generator (4) and a network bridge (14). A dc link (12) is connected
between the generator bridge (10) and the network bridge (14). A filter
(16) having network terminals is connected between the network bridge
(14) and the supply network. A first controller (18) is provided for
controlling the operation of the semiconductor power switching devices of
the generator bridge (14). Similarly, a second controller (46) is
provided for controlling the operation of the semiconductor power
switching devices of the network bridge (14). The first controller (18)
uses a dc link voltage demand signal (VDC_GEN*) indicative of a desired
dc link voltage to control the semiconductor power switching devices of
the network bridge (10) to achieve the desired level of dc link voltage
that corresponds to the dc link voltage demand signal (VDC_GEN*). The
second controller (46) 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 (14), and a voltage demand signal (VTURB*)
indicative of the voltage to be achieved at the network terminals of the
filter (16) to control the semiconductor power switching devices of the
network bridge (14) to achieve the desired levels of power and voltage
that correspond to the power and voltage demand signals (P* and VTURB*).