System and method for distributed grid control with sub-cyclic local response capability

A high-voltage power grid comprising:

• a plurality of impedance injection modules coupled to a high-voltage transmission line at a number of locations in the high-voltage power grid, each impedance injection module having;
• a controller that senses disturbances and/or other conditions on the high-voltage transmission line of the high-voltage power grid and reacts by generating and injecting inductive and/or capacitive impedances of appropriate magnitude onto the high-voltage transmission line via an injection transformer coupled to one of the high-voltage transmission lines, the controller providing a sub-cyclic response capability of the respective impedance injection module;
• and
• a transceiver for high-speed communication with other impedance-injection modules within a local group of impedance injection modules to enable coordinated response of the other impedance-injection modules within the respective local group of impedance injection modules to disturbances on the high-voltage transmission line;
• a group of local centers, each local center within the group of local centers having a high-speed transceiver for high-speed communication with impedance injection modules within a respective local group of impedance injection modules and with other local centers to enable coordinated response of all impedance injection modules associated with that group of local centers;
• wherein each local center includes a communication link to and from a system utility, the communication link to and from a system utility being for communication at a lower speed than the high-speed communication between impedance injection modules and between impedance injection modules and local centers.

A high-voltage power grid having a distributed control with hierarchical supervision of the power grid comprising:

• a plurality of impedance-injection modules coupled to a high-voltage transmission line at a number of locations in the high-voltage power grid, each impedance injection module having;
• a controller that senses disturbances and/or other conditions on the high-voltage transmission line of the high-voltage power grid and reacts by generating and injecting inductive and/or capacitive impedances of appropriate magnitude onto the high-voltage transmission line via an injection transformer coupled to one of the high-voltage transmission lines, the controller providing a sub-cyclic response capability of the respective impedance injection module;
• and
• a transceiver for high-speed communication with other impedance-injection modules within a local group of impedance injection modules to enable coordinated response of the other impedance injection modules within the respective local group of impedance-injection modules to disturbances on the high-voltage transmission line;
• a group of local centers, each local center within the group of local centers having a high-speed transceiver for high-speed communication with impedance injection modules within a respective local group of impedance-injection modules and with other local centers to enable coordinated response of all impedance-injection modules associated with that group of local centers;
• each local center having a communication link to and from a system utility, the communication link to and from a system utility being for communication at a lower speed than the high-speed communication between impedance injection modules and between impedance-injection modules and local centers;
• wherein the controller of each impedance injection module provides a sub-cyclic response capability to other impedance-injection modules within the local group of impedance injection modules using the high-speed communication between impedance injection modules within the respective local group;
• the distributed control with hierarchical supervision of the high-voltage power grid providing steady-state power-flow control, line-current balancing, transient and small-signal stability, power-oscillation damping (POD), sub-synchronous resonance (SSR) damping, and/or responses to other high-voltage transmission-line disturbances.

A method of responding to disturbances on a high-voltage transmission line of a high-voltage power grid comprising:

• providing a plurality of impedance injection modules coupled to a high-voltage transmission line at a number of locations in the high-voltage power grid, each impedance injection module having;
• a controller that senses disturbances and/or other conditions on the high-voltage transmission line of the high-voltage power grid and reacts by generating and injecting inductive and/or capacitive impedances of appropriate magnitude onto the high-voltage transmission line via an injection transformer coupled to one of the high-voltage transmission lines;
• and
• a transceiver for high-speed communication with other impedance-injection modules within a local group of impedance injection modules to enable coordinated response of the other impedance-injection modules within the respective local group of impedance-injection modules to disturbances on the high-voltage transmission line;
• also providing a group of local centers, each local center within the group of local centers having a high-speed transceiver for high-speed communication with impedance-injection modules within a respective local group of the plurality of impedance-injection modules and with other local centers within the group of local centers;
• and
• providing a communication link between each local center and a system utility, the communication link between each local center and the system utility being for communication at a lower speed than the high-speed communication between impedance injection modules and between impedance injection modules and local centers;
• when a disturbance and/or other condition on the high-voltage transmission line needing a response is sensed by a respective controller, causing the respective controller to generate and inject inductive and/or capacitive impedances of appropriate magnitude onto the high-voltage transmission line to reduce or correct the disturbance and/or other condition on the high-voltage transmission;
• and
• causing the respective controller to communicate with the other controllers in the other impedance-injection modules in the local group through the respective transceivers to initiate cooperative responses to the disturbance and/or other condition is appropriate;
• also when the disturbance and/or other condition on the high-voltage transmission line needing a response is sensed by the respective controller
• causing the controller in the respective impedance injection module to communicate with the respective local center;
• causing the respective local center to communicate with the other local centers;
• and
• causing such other local centers to communicate with the respective other impedance injection modules;
• whereby when the disturbance and/or other condition on the high-voltage transmission line needing a response is sensed by the controller of any impedance-injection module associated with any local center within the group, a coordinated response to the disturbance and/or other condition may be initiated by all impedance-injection modules associated with all local centers in the group of local centers;
• and
• further using the communication link between each local center and the system utility to coordinate with the system utility to provide the system utility with consolidated data and status information and receive commands and responses for implementation by the impedance-injection modules in case of system-level problems on the high-voltage power grid.