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Overview

dubasSTATCOM

Power management is imperative for any industrial or commercial establishment big or small. Without good power management practices, companies could face problems of failed equipments, regulatory penalty and inefficient operations. Power quality is the most important component of an organization’s energy management policies and programs and implies how power is drawn and utilized without corrupting the source and distribution network as well your compliance to statutory regulations.

Why does power get polluted?
	Most of the present day loads are inductive loads (For instance computer loads, induction motors, power transformers, lighting ballasts, welding furnaces etc. ). This causes poor load current phase angle and results in poor power factor at the point of utilization.
	Many loads like rectifiers, variable speed drives, switch mode power systems and other kinds of electronic loads distort the current waveform substantially. This results in large current harmonics in the network. This harmonic current is a scourge for all other loads connected in the network as well for the utility.

This pollution causes
	Higher maximum demand charges and higher tariffs.
	Overheating of all upstream and downstream current carrying cables and components.
	Higher wear and tear of all components / equipments and hence premature ageing of such components / cables.Stray tripping of breakers and protection relays.
	Underutilization of utility power resource, as reactive power uses up the capacity which otherwise could have been used for serving the load.
	Flickers, sags and surges.

Benefits of power management There are considerable direct savings for a company by improving the power quality. Poor power factor not only attracts penalties from the supplying company, but can also amount to disconnection of the power itself. Drawing power at unity input power factor has attractive incentives from the utility and maximum demand charges are also reduced considerably. However, major savings come in the form of higher utilization of source, reliable operation, increased life of all connected components/equipments in the distribution network. There are stringent standards of compliance applicable today:
	EC 61000 - 3 -2 Limits for harmonic current emissions, equipment < 16A
	EC 61000 - 3 - 4 Limits for harmonic current emissions, equipment >16 A

With the privatization of electrical utility companies, the standards are followed more vigorously. Further, harmonic currents generated also pollute and cause problems to the neighbouring industries when you are sharing a common distribution transformer, a common practice in industrial complex and multistoried complex. It also loads the distribution transformer with reactive power demand allowing connected users to utilize only a portion of the capacity of the distribution transformer.

Above all these, poor power factor and harmonics makes the power generating stations to circulate wasteful power to support large quantum of reactive power demands, which is a national waste.

Passive to Active Solutions
Presently passive solutions are employed to combat the problems of the power factor and harmonics. Power factor capacitors are used to compensate the lagging power factor. Capacitors are either employed as a fixed installation in the network or switched either by a contactor or a thyristor switch. Capacitor compensation is a passive compensation with its limitations to compensate for dynamically changing loads. Trying to achieve high power factor sometimes lead to dangerous situations of resonance. For harmonic suppression, presently passive solutions with LC combinations are employed. This tuned filter has the limitation of being specific solution for a specific frequency.

Dubas offers ACTIVE solid state solutions for today’s dynamically changing loads. These are state of the art technology PWM current generators which compensates the reactive currents. Dubas ePFCs provide precise dynamic compensation for any type of load and provides dynamic solution to improve the power factor to near unity. Similarly H-Filters compensates the harmonics in the network dynamically to specified levels.