Closed-circuit power line communication

A system for closed-circuit power line communication, comprising:

• at least a first power line and a second power line connected to at least one electrical device configured to receive a data signal;
• an auxiliary line connected to the at least one electrical device, and configured to provide a ground connection;
• at least one transmitter configured to generate first data signals for transmission over the first power line and the second power line, respectively, to the at least one electrical device;
• and
• a low-pass common-mode filter connected to the first power line and the second power line, and configured to provide closed-circuit data communication between the transmitter and the at least one electrical device, wherein the low-pass common-mode filter comprises at least one coupling capacitor between the first power line and the second power line such that at least the polarities with respect to ground of the first data signals transmitted over the first power line and the second power line, respectively, are substantially similar,
• wherein the first data signals carried by the first power line and the second power line, respectively, are symmetrical with respect to the auxiliary line, and
• wherein the auxiliary line is connected to at least a reactive element, such that that a polarity of the first data signals carried by the first power line and the second power line have the same polarity and such that the first data signals on the first power line and the second power line are opposite in polarity to the first data signals carried by the auxiliary line.

A system for closed-circuit power line communication, comprising:

• at least a first power line and a second power line connected to at least one electrical device configured to receive a data signal;
• an auxiliary line connected to the at least one electrical device, and configured to provide a ground connection;
• at least one transmitter configured to generate first data signals for transmission over the first power line and the second power line, respectively, to the at least one electrical device;
• and
• a low-pass common-mode filter connected to the first power line and the second power line, and configured to provide closed-circuit data communication between the transmitter and the at least one electrical device, wherein the low-pass common-mode filter comprises at least one coupling capacitor between the first power line and the second power line such that at least the polarities with respect to ground of the first data signals transmitted over the first power line and the second power line, respectively, are substantially similar,
• wherein the electrical device is configured to use the first data signals to charge a capacitor.

A closed-circuit power line communication system, the communication system comprising:

• a first power line and a second power line connected to at least one electrical device configured to receive a data signal;
• an auxiliary line connected to the at least one electrical device and configured to provide a ground connection;
• a transmitter configured to generate the data signal and apply the data signal between the auxiliary line and the first power line for transmission to the at least one electrical device;
• and
• a low-pass common-mode filter connected to the first power line and the second power line and configured to provide closed-circuit data communication between the transmitter and the at least one electrical device,
• wherein the auxiliary line is connected to a predetermined potential via at least one reactive element,
• wherein the data signal comprises a first data signal component transmitted over the first power line, a second data signal component transmitted over the second power line, and a third data signal component transmitted over the auxiliary line;
• and
• wherein the polarities of the first data signal component and of the second data signal component are equal, and wherein polarities of the first data signal component and the second data signal component are opposite to a polarity of the third data signal component.