• Reactive control is an important tool for voltage regulation and for optimizing available power utilization. It can also be used for attaining better stability of the system. It has therefore become a very important technique to improve an old distribution network that is being over utilized and is ailing with recurring problems such as flickering of voltage, frequent system outages and a normally low voltage at the consumer end. The author has attempted to apply reactive control to improve power distribution networks which are over-loaded and are ailing with such problems. In this part the author provides all relevant aspects of a reactive control and carries out an exhaustive analysis of a system for the most appropriate control. Harmonic effects and inductive interferences as well as use of filter and blocking circuits are covered. EMC/EMI (Electromagnetic compatibility and interferences). Capacitor switching currents and surges and methods of dealing with these are also described. This part considers reactive power control with the use of shunt and series capacitors. The controls may be manual or automatic through electromagnetic or static devices. Protection of capacitors and capacitor banks as well as design, manufacturing and test requirements, installation and maintenance are also covered, the main thrust being on the application of power capacitors.

• Application of series capacitors and analysis of an uncompensated transmission line and the capability of power transfer and system regulation with and without series compensation are also presented. Autoreclosure scheme for transient stability and SCADA system for dynamic stability of a power network. Serial data transmission, communication interfaces and communication protocols.

• To clarify the subject the basics and the behaviour of power capacitors in operation are also discussed.

• This part also briefly describes different types of power reactors required to control inrush currents, suppress system's harmonic disorders, limit system fault level and absorb the excessive charging currents on an EHV system.