Dang Mike - You're faster off the line with what ever tool your searching with than freepatentsonline.com. (You have to register, but it provides excellent search tools, up there with the pay for service Delphi)
As Mike said, this isn't a balanced (technical) power application. The balanced power cancellation of noise that Woodsyi refers to is that ideally, transverse (normal) mode noise becomes differential mode noise, referenced to ground, by virtue of the grounded center tapped transformer action. When this noise is shunted to ground via capacitors, it cancels in that ideally that noise has an equal but opposite phase component which is likewise shunted to ground and they add to 0.
This new technology seeks to take the shunted surge and reintroduce it into an antiphase winding of a transformer or autoformer and thereby cancel it without creating perturbations on the neutral or ground line. Very slick. It is specific to surge/spike protection, and doen't offer filtering which is provided by ancilliary circuitry. While the patent initially uses a classical non linear voltage switch (MOV, SAD), as an enhancement they show their previously developed tracking surge switch which they developed and delivered in their previous patents and offerings.
