TABLE OF CONTENTS This chapter discusses the recent developments in modeling of multi-functional multi-converter FACTS-devices in power flow analysis. The objectives of this chapter are:
to model not only the well-recognized two-converter shunt-series FACTS-device - UPFC, but also the latest multi-line FACTS-devices such as IPFC, GUPFC, VSC-HVDC and M-VSC-HVDC in power flow analysis,
to establish multi-control functional models of these multi-converter FACTS-devices to compare the control performance of these FACTS-devices.
to handle the small impedances of coupling transformers of FACTS-devices in power flow analysis.
Among the converter based FACTS-devices, the Unified Power Flow Controller (UPFC) [10][11] is a versatile FACTS-device, which can simultaneously control a local bus voltage and power flows of a transmission line and make it possible to control circuit impedance, voltage angle and power flow for optimal operation performance of power systems. In recent years, there has been increasing interest in computer modeling of the UPFC in power flow and optimal power flow analysis [12],[15] [24], However, in the most recent research work, the UPFC is pri-marily used to control a local bus voltage and active and reactive power flows of a transmission line. As reported in [24], in practice, the UPFC series converter may have other control modes such as direct voltage injection, phase angle shifting and impedance control modes, etc.
In contrast to the practical control possibilities of the UPFC, there has been a lack of modelling of the various control modes in power system analysis. In this section, besides the basic...
