Power Factor Correction on Progressive Dynamics Converters.

horton333 wrote:
ok so seems there is no PF correction, so I may be a bit limited at the high end of of charging with my generator comparatively speaking. There are at least two brands that advertise a PF of 95 or better.
It not a deciding factor, just one of many.

Why not post what you have and what you need and see if the two should cross?

ok so seems there is no PF correction, so I may be a bit limited at the high end of of charging with my generator comparatively speaking. There are at least two brands that advertise a PF of 95 or better.
It not a deciding factor, just one of many.

Pf comes into play down here with the BORG versus flaky hotel wiring. The variable voltage (10 turn pots) saves me hiney.

Trying to say it without technical gobbledegook, when the power factor is less than 1, the available power cannot be used with 100% efficiency. When using a generator with a typical 0.7 power factor converter, the generator can supply only 70% of its rated VA, or looking the other way, the converter needs a generator rated at 143% VA of what the converter draws in watts. For example, a generator rated at 1600 VA can supply 1120 watts to a 0.7 pf converter.

There are 2 different types of power factor. The motor type is different from the power converter type, and motor power factor correction techniques will not work with a power converter. Correction in a power converter requires active circuitry. It's fairly complex but like everything else is being packaged into chips and will eventually not add a whole lot of cost. With shore power the inefficiency is still there but it's doubtful an RV user would care about it. It does affect the power company, and they meter the power factor of industrial users, charging more when it's less than 1. Because of the overall impact on the grid, the newest Energy Star guidelines require power factor correction in power supplies, and in Europe it's a government mandate. I'd expect it to become widespread in RV converters someday.

Freakin' ricochet I tell ya

DrewE wrote:

kellertx5er wrote:

pianotuna wrote:
Hi,

PF matters when powering the converter with a generator.

Power factor correction only benefits the system upline from the point of correction. So yes, the generator will see improvement. However, your 30 (or 50) amp main breaker will see NO benefit and you will still be limited by that device.

:h Why wouldn't the main breaker (and the branch breaker feeding the converter) also see benefit from power factor correction in the converter? They are, after all, upline from the converter, and the actual, measurable current that flows through them would be reduced.

For converters such as Xantrex which have PF correction, this is correct. Any devices which connect at the pedestal would offer no benefit at the panel main breaker.

smkettner wrote:
Poor power factor increases the apparent power needed not the actual power consumed. Amps and volts stays the same. Power factor describes what % of the sine wave the device can use. Must use the entire wave to get the full generator rating.

Read this Xantrex White Paper on Power Factor

Power factor indeed does affect the apparent power and not the actual power; it's defined as the ratio of actual power to apparent power. Apparent power is defined as the RMS voltage multiplied by the RMS current. Actual power is subtly different: the RMS value of the instantaneous current multiplied by the instantaneous voltage. (In all of these cases, you can basically think of "RMS" as meaning integration over time if you happen to like thinking about calculus.)

Based on the definition of power factor, it's only true that the current and voltage levels remain constant with varying power factors if the apparent power remains constant, and therefore the actual power varies with the power factor.

If the actual power is constant, then varying the power factor must very much lead to differences in the voltage and current. With utility AC power, which is for practical purposes a fairly pure AC voltage source, the current is the component that will change. A device with a poor power factor will use more current than a device with a good power factor that consumes the same actual power. Incidentally, this is very much real current, measured by an ammeter, and causing circuit breakers to pop and fuses to blow if sufficiently high.

The white paper states as much in the second paragraph: "The improved power factor results in approximately 30% less AC input current required to deliver the same DC charging current." When talking about a converter, the DC charging current can serve as a rough measure of or equivalent to the actual power.

Poor power factor increases the apparent power needed not the actual power consumed. Amps and volts stays the same. Power factor describes what % of the sine wave the device can use. Must use the entire wave to get the full generator rating.

Read this Xantrex White Paper on Power Factor