POWER FACTOR CORRECTION

• As we approach the new millennium, computer technology and electronic controls are now widespread in our industries and building services with many production processes being totally dependant upon their uninterrupted operation. The majority of these controls are extremely sensitive to electricity supply disturbances and pollution. The overall Quality of the power supply and efficiency of electrical systems is now of paramount importance.

• The Capacitor industry promotes its’ products and applications as solutions for many of the known electrical system problems such as Harmonic pollution and Power factor correction. Major improvements have taken place in the manufacture of power capacitors during the last 2 decades with the abolition of PCB impregnation in 1978, the advent of the dry capacitor in 1982 and the introduction of internal protection devices in 1989*. (Modern capacitors are almost all manufactured to the same international standard (BS EN 60831/1/2). (The quality of each manufacturer’s product varies very little and the level of reliability has significantly improved)).

• What has not significantly improved in the last 2 decades is the control and protection systems utilised by Power Factor correction manufacturers. Although advances have been made in the controlling relays, the measuring methods and connection/disconnection speeds have not significantly altered. Some additional alarm and measurement facilities have been added. Contactor manufacturers have designed specific products to switch capacitors, however the levels of harmonic pollution on modern electrical systems and the onerous duty of capacitor switching means that they are still prone to early failure.

• At ESTA we believe that power capacitor products should keep pace with the industry that it services, for this reason we have chosen to represent, promote and supply Elspec’s Real Time Power Factor System (RTPFC), the most innovative microprocessor controlled, semiconductor switched Power Factor product available today.

• Historically Power Factor Correction capacitors and equipment have been utilised in an attempt to reduce electricity charges (power factor penalties) or as a means of maximising supply capacity by the reduction of KVA maximum demand. Competition between the now privatised electricity utilities has resulted in the first of these becoming almost non-existent, many electricity suppliers having either abolished penalties altogether or reduced the required target power factor to a level that is easily achievable with modern machinery and drives. This has led to a "levelling off" of the capacitor market and although sales have been steady there is no growth.

• Competition between capacitor manufacturers is intense and in an attempt to stimulate the market Capacitor and capacitor equipment suppliers have begun to concentrate more on "Power Quality" rather than savings and "payback". Although standard PFC does improve power quality, the technology used to control the systems is slow and inefficient and this limits it’s effectiveness to stabilise voltage or react to the rapid load changes that are becoming more common with modern electronically controlled plant and building services. Additionally the use of electro mechanical switchgear generates electrical disturbances.