PFCs finally made easy

But optimizing PFC circuits for a particular application has been difficult – until now. The PL Product is a user driven software for Design Engineers that is designed to identify and select PFC inductors over a range of output power more quickly.

Given designers input, regarding the desired circuit operating parameters, the PL Product calculates the product factor required for the application and correlates it to Pl Product curves. These interactive Pl Product curves and the resulting computations, quickly help Design Engineers select a PFC inductor to meet their specific requirements.

One reason why PFC circuits can be difficult to design is that engineers must fully understand the PFC inductor’s operating characteristics and its effect on the PFC circuit as design criteria changes. The PL Product makes it easier for circuit designers to understand the relationship and trade-offs among circuit parameters and the inductor.

The PL Product also gives Precision – a leading manufacturer of inductors and other magnetic components – a more effective way of relating the performance of PFC inductors. Seeing how circuit and PFC inductor characteristics behave under various operating conditions makes a selection of the right inductor much easier for engineers.

The PL Product was designed by Precision, Inc.. Mr. Welly Chou; a Precision Sr. Design Engineer, was selected for presentation of a paper on the derivation of the PL Product and PFC inductor selection. The paper was presented at the 25th Annual IEEE Applied Power Electronics Conference (APEC) in February, 2010. The interactive tool itself can be accessed through the Precision website: www precision-inc.com.

A new factor in efficiency
Growing emphasis on energy conservation and the demand for more energy-efficient products has led manufacturers to incorporate PFC into their power supply designs. For the past decade, European Union regulations have specified line current harmonic content. Reducing line current harmonics can only, as a practical matter, be achieved by PFC. In essence all consumer electronic equipment sold in the EU – including office computers, printers, and copiers -employs PFC. Similar regulations have been proposed in the US.

But how does power factor correction improve energy efficiency? In an AC system, at low values of power factor, more apparent power needs to be transferred to get the same real power.

Essentially, PFC makes a higher-current electrical load (like an electric motor) with a power factor of less than 1 appear as a purely resistive load (like a light bulb) with a power factor of 1 – thus reducing the apparent power. More of the energy supplied by the source is consumed by the load.

Applying the PL Product Tool
PFC circuits employ a number of magnetic components, and inductors play a critical role in the boost pre-regulator for PFC. By using the interactive PL Product Tool, engineers can easily calculate PL Product and characterize PFC inductors over a range of output power. Coverage is 200 to 1,000 watts output power. This gives circuit designers insight into the relationship among output power, ripple current, switching frequency and the PFC inductor, and allows them to make educated trade-offs.

The PL Product Tool then specifies the standard Precision inductor component that is optimum for the PFC application. For the Design Engineer, it documents circuit and PFC inductor characteristics, in real time under various operating conditions.  If no standard component is a close fit, Precision uses data from the tool as a starting point for specifying a custom inductor.

About Precision
If you would like to experience the PL Product yourself…go to: http://pfc.precision-inc.com/
Precision Incorporated is a designer and global manufacturer of magnetic components, with more than a quarter century of experience in custom magnetics. Precision’s in-house staff of 12 engineers has experience in a broad range of applications, including power factor correction.

Precision works in partnership with a client’s design engineers to ensure that the magnetic components are optimized for that specific application. The company offers a wide selection of standard PFC product families and develops semi-custom PFC products for multiple IC controllers.

For more information on the PL Product, e-mail Precision, Inc. at:  PLinfo@precision-inc.com     or, Call: 612-561-6880 and ask for information on the new PL Product from Precision, Inc.