Current modulated messages generated by PFC circuits for allocating appliances with management systems in smart grid applications

This paper shows a technical solution to locate and to identify an electrical load and to allocate it with controllers for interchanging clearing and control information e.g. in smart grid applications. It is a solution where the controller can be easily integrated in smart meters, substations and in external control devices. The appliance uses its integrated switching power supply for establishing a communication link. Therefore the control of the integrated power factor correction (PFC) is modified. Thus plugging to a normal socket-outlet is sufficient for allocating the device with controllers in a way like a Plug'n'Play system. The technique does not need new lines and can be installed in existing electrical installations with minimal effort. The allocating technique uses two different communication channels. The first one is a unidirectional channel with a very low frequency which uses the electrical current as a carrier, and the second one is a bidirectional channel. The management system detects, if an appliance is connected to the pathway behind the controller and it establishes an individual communication link. The controller can check its responsibility because grid's impedance for low frequencies is much lower than the impedance of the connected loads so that the current flows only on the pathway to the transformer station. The method has some more features such as setting up a hierarchized system with several management units for different tasks such as power management, clearing services or congestion management.