Structure and Control of Power Converters

Apart from the breaking and transferring devices, all other power quality (PQ) enhancement devices like DSTATCOM, DVR, UPQC etc. are based on power converters. Furthermore modern FACTS devices like STATCOM, SSSC, UPFC etc. also employ power converters. However, FACTS devices have much higher power rating than PQ enhancement devices since they are used in bulk power transmission systems. Moreover, their operation philosophy is also different as they are assumed to work under balanced sinusoidal conditions. As a consequence, the control strategies of FACTS devices are different from the PQ enhancement or Custom Power devices. Since power converters have an important role to play in modern power systems, we discuss their topologies and control strategies in this chapter. For the background materials in the area of Power Electronics, there are numerous excellent textbooks, e.g., [1–3].