The DC value that I spoke of is the average value of the current waveform because it is all above zero.
I've performed a simulation of your signals and I can see that the power factor does indeed seem low. The maximum theoretical power factor of a rectified system with no diode drop is 0.707. With the diode drop, or dead zone, I get a power factor of about 0.64 (from looking at your waveform and guessing at what voltage the current starts to flow). If I then introduce a phase shift such as you may get through inductance in the circuit then even with 30 degrees the power factor is only down to 0.52. Do you have another means of measuring the power, and if so, what is that measuring?
I have a few questions for you about how the PM3000A is setup:
- Is the PM3000A set to defaults?
- has it been calibrated/verified recently?
- Is it detecting the frequency correctly at 400Hz?
- Are you using the PM internal shunt or also using a CT, external shunt, or other current measurement module?
- How are you measuring the PF, for example, are you reading it from the PM3000A or software?
- Are you taking fundamental measurements (FUND key) or using AC only coupling?
I have attached a copy of the mathematics I used to perform the calculations. This may be useful to you or someone else reading this thread to help clarify how the PM3000A computes the parameters.
I look forward to hearing from you soon.