Systematic Synchronous Compensator Research Paper

CHAPTER-4 STATIC SYCHRONOUS COMPENSATOR (STACOM)

4.1 INTRODUCTION:

A static synchronous compensator (STATCOM), and also known as a static synchronous condenser (STATCON),is a regulating equipment used on alternating current electricity transmission networks. It is based on a power electronics voltage-source converter and that can act as either a source or a sink of reactive AC power to an electricity network. If associated with a source of power it can also provide active AC power. It is a member of the FACTS family of devices. It is essentially modular and electable.

4.2 USES:

Usually a STATCOM is installed to maintain electricity networks that have a poor power factor and habitually poor voltage regulation. There are however, other uses,

The reactive power at the terminals of the STATCOM depends on the amplitude of the voltage source. For example, if the terminal voltage of the VSC is higher than the AC voltage at the point of connection, the STATCOM produces reactive current conversely, when the amplitude of the voltage source is lower than the AC voltage, it absorbs the reactive power. The response time of a STATCOM is shorter than that of a static Var compensater (SVC), mostly due to the fast switching times provided by the IGBTs of the voltage source converter. The STATCOM also provide the better reactive power support at low AC voltages than an SVC, since the reactive power from a STATCOM decrease linearly with the AC voltage (as the current can be maintained at the rated value even down to low AC

For system without compensation, the phase angle of current has been related to load giving active power in phase with load voltages. Since load assumed inductive it requires reactive power for proper operation and hence source must supply it which increases the current through source side via power line. If reactive power is supplied near load, the line current may be reduced which results in reduced power loss and improves the voltage regulation at load terminals.

This can be done using current source, voltage source or with a capacitor. Current source device is used to compensate reactive components of load current which improves the voltage regulation of system and reactive current components from source is also reduced. If lad needs loading compensation then inductor is required. A current source/voltage source can be required for inductive shunt compensation. The main advantage using this voltage or current source, VAR generator is that reactive power generated is independent of voltage at point of connection.

4.6 FUNCTION OF