I attach a letter from Emidio Laureti about PNN and the displacement current issue.
It's 5 pages long, so I think it's better if I don't copy it in a post because it would be too long 
Has the Italian Association for Space Propulsion Development (ASPS) ever run the PNN device powered by batteries, self-integrated in the same moving platform as the PNN?
Or have all the PNN tests been conducted with a power cord supplying the power from an external power supply that is stationary with respect to the moving PNN device?
It's the second one, the power supply is stationary and external to the thruster. Laureti said that PNN is very demanding in term of current. In fact, for him the best solution would be a nuclear power reactor. As far as I know they've never mentioned a battery powered prototype.
EDIT: Laureti confirmed, no batteries.
Please be aware of the issues associated with conducting tests with a power cord going to a device on a pendulum. A spacecraft in space cannot have a power cord going to it from the Earth. There are many issues associated with electromagnetic Lorentz forces from the power cords, thermal expansion of the power cord producing forces on the tested device and there are conservation of energy issues when you have power flowing from a stationary device not mounted on the pendulum.
Prof. Yang in China just falsified (in a 2016 report) her prior claimed results for the EM Drive, upon using batteries to supply power to her EM Drive on a torsional pendulum instead of using power from a stationary supply.
Prior to that Brito, Marini and Galian in Argentina falsified their decades long work on propellant-less propulsion also by using batteries to supply power to their device on a torsional pendulum instead of supplying power from a stationary power source. Marini and Galian have an article in the Journal of Propulsion of Power of the AIAA detailing the nullification of Brito's prior results using power from a stationary power source.
On behalf of Laureti:
There are 3 different and convergent methods to avoid this ambiguity and they all require time and experimental application for the due verifications:
1 ) to make a ballistic pendulum whose oscillation isn't perturbed by any thermal dilatation (and our new kind of pendulum is made that way).
2) to measure with a thermal camera the temperature in the zones in which the thermal perturbation that produces the possible thrust error occurs. Practically one does a double test, one with the prototype and one with an heater in place of the prototype
The heater must provide the same thermal gradients of the prototype coaxial cable
Conclusions: the heater obviously mustn't have any propulsive effect on the ballistic pendulum unlike the prototype.
3) to do tests also with the prototype rotated 180° on ballistic pendulum: that is to have thrusts in two different directions.
Locking for lack of interest.
