A modular power flow control system is described for optimizing power flow control in a multi-phase power transmission system. Identical impedance injection modules are arranged in an mn matrix, where m is the number of series-connected modules inserted into each phase (forming a leg of the installed bank of modules), and n is the number of parallel-connected legs per phase. Each impedance injection module in a phase is configurable to collectively insert a pre-determined (controllable) power control waveform into the phase to which it is attached. The modular flow control system is agile with respect to configurability, reconfigurability, maintenance, size, weight, and cost.

In the presented solution reactive power is compensated for in connection with a power transmission line with an arrangement which comprises at least one transformer and at least one reactive power compensator. The at least one reactive power compensator comprises a voltage source converter and switched elements. The switched elements may be thyristor switched capacitors and/or thyristor switch reactors, for example. The voltage source converter may provide reactive power in a linear or step less manner. The transformer is a three winding transformer having a high voltage side connectable to the power transmission line, a first low voltage side connected to the voltage source converter and a second low voltage side connected to the switched elements.

In the presented solution reactive power is compensated for in connection with a power transmission line with an arrangement which comprises at least one transformer and at least one reactive power compensator. The at least one reactive power compensator comprises a voltage source converter and switched elements. The switched elements may be thyristor switched capacitors and/or thyristor switch reactors, for example. The voltage source converter may provide reactive power in a linear or step less manner. The transformer is a three winding transformer having a high voltage side connectable to the power transmission line, a first low voltage side connected to the voltage source converter and a second low voltage side connected to the switched elements.

A power flow control subsystem having multiple configurations is described. The subsystem is three-way configurable: as a transportable configuration, as a deployable configuration, and as a transmission line configuration. The transportable configuration includes a collection of impedance injection modules and at least one bypass module carried on a wheeled vehicle such as a trailer. The deployable configuration is an assembly of the collection of impedance injection modules and at least one bypass module, operable to perform power flow operations. The transmission line configuration includes connection of a deployable configuration to a phase of a high voltage transmission line for performing power flow control. The deployable configuration may be open or closed frame. The deployable configurations may be mounted on one or more wheeled vehicles in a mobile subsystem, or semi-permanently mounted at a ground site.

A reactive power optimization method for integrated transmission and distribution networks related to a field of operation and control technology of an electric power system is provided. The reactive power optimization method includes: establishing a reactive power optimization model for a transmission and distribution network consisting of a transmission network and a plurality of distribution networks, in which the reactive power optimization model includes an objective function and a plurality of constraints; performing a second order cone relaxation on a non-convex constraint of a plurality of distribution network constraints of the plurality of constraints; and solving the reactive power optimization model by using a generalized Benders decomposition method so as to control each generator in the transmission network and each generator in the plurality of distribution networks.

A reactive power optimization method for integrated transmission and distribution networks related to a field of operation and control technology of an electric power system is provided. The reactive power optimization method includes: establishing a reactive power optimization model for a transmission and distribution network consisting of a transmission network and a plurality of distribution networks, in which the reactive power optimization model includes an objective function and a plurality of constraints; performing a second order cone relaxation on a non-convex constraint of a plurality of distribution network constraints of the plurality of constraints; and solving the reactive power optimization model by using a generalized Benders decomposition method so as to control each generator in the transmission network and each generator in the plurality of distribution networks.

In prior art grid systems, power-line control is done by substation based large systems that use high-voltage (HV) circuits to get injectable impedance waveforms that can create oscillations on the HV power lines. Intelligent impedance injection modules (IIMs) are currently being proposed for interactive power line control and line balancing. These IIMs distributed over the high-voltage lines or installed on mobile platforms and connected to the HV power lines locally generate and inject waveforms in an intelligent fashion to provide interactive response capability to commands from utility for power line control. These IIMs typically comprise a plurality of impedance-injection units (IIUs) that are transformer-less flexible alternating current transmission systems interconnected in a series-parallel connection and output pulses that are additive and time synchronized to generate appropriate waveforms that when injected onto HV transmission lines are able to accomplish the desired response and an provide interactive power flow control.

Aspects of the present disclosure are directed to a power filter comprising a first input configured to receive measurements of electrical characteristics of source power lines from a power source, a second input configured to receive measurements of electrical characteristics of load power lines to a load, an output configured to couple to output power lines to provide output current compensation signals, a power converter coupled to the power output and configured to receive input power, receive input control signals and provide the output current compensation signals based on the input control signals, and control circuitry coupled to the first input, the second input and the power converter and configured to provide the control signals to the power converter, wherein the control circuitry is configured to detect a connection status of a neutral connection to the load, wherein the connection status includes one of connected and disconnected.

Aspects of the present disclosure are directed to a power filter comprising a first input configured to receive measurements of electrical characteristics of source power lines from a power source, a second input configured to receive measurements of electrical characteristics of load power lines to a load, an output configured to couple to output power lines to provide output current compensation signals, a power converter coupled to the power output and configured to receive input power, receive input control signals and provide the output current compensation signals based on the input control signals, and control circuitry coupled to the first input, the second input and the power converter and configured to provide the control signals to the power converter, wherein the control circuitry is configured to detect a connection status of a neutral connection to the load, wherein the connection status includes one of connected and disconnected.

An apparatus for deicing and compensating reactive power is a mobile apparatus eWatch that includes a primary coil generating electromagnetic force, wherein a circuit comprises a voltage source and a switcher, and reactive power compensator that comprises an AC/AC converter and a reactive power compensating coil. The apparatus comprises blades to remove snow and ice.