Abstract: A transformer for power line reactance injection that can be adapted in manufacturing to different operating current ranges by interchanging primary windings having one, two, three, four or more laminar turns. Through its use of gaps in the magnetic circuit that are filled with high temperature, high thermal conductivity dielectrics, this transformer has tolerance to very high fault currents, and it can be passively cooled by the use of fins on the exterior walls of the core.

Abstract: A filter network is insertable into a power transmission line, to handle disturbances in the power transmission line. A first circuit has an RC network in parallel with a surge arrestor, to bypass high frequency disturbances of the power transmission line. A second circuit has inductors for carrying low-frequency power to and from impedance injection units.

Abstract: A modular liquid cooling block is described for cooling high current devices deployed in power flow control systems. The liquid cooling blocks may have separate shower heads which may be configured for direct impingement, indirect impingement, or parallel flow cooling configurations. Voltage isolation of liquid cooling blocks from an enclosure of the power flow control system and from associated equipment enables serial or parallel connected power flow control units to inject substantial reactive power that may be configurable into a power transmission line. Associated power flow control systems are monitored for temperature, flow rate and pressure gradient. Redundant pumps and fan radiators contribute to reliable operation. Automatic shutdown and alarm may be provided.

Abstract: The presence of injected DC has harmful consequences for a power grid system. A piecewise sinusoidal ripple voltage wave at the line-frequency that rides on the main capacitor bank of the power converter is observed. This observation leads to a new detection method and mitigation method. A two-stage control circuit is added to the operation of a power converter that controls power line impedance in order to mitigate the injected DC and to block DC circulation. This control computes a correction angle to adjust the timing of generated pulsed square waves to counter-balance the ripple. A functional solution and the results of experiments are presented. Furthermore, an extraction method and three elimination methods for this ripple component are presented to allow dissipation of DC energy through heat and/or electronic magnetic wave, or to allow transformation of this energy into usable power that is fed back into the power grid.

Abstract: Sheet metal construction is described for achieving high strength at low weight for a power reactor and for an impedance injection module incorporating the power reactor. Clamping plates are used to retain the core and the windings of the reactor. Integrated features of a specialized frame of the impedance injection module include flanges for structural rigidity, a convenient yoke plate for lifting by crane, feet for mounting insulators, and sufficient strength to maintain mechanical integrity during normal operation and also during fault conditions. The specialized frame provides a light weight assembly suitable for mounting on power transmission lines as well as on ground assemblies. The specialized frame can reduce the cost of the total enclosure to around 25% of the cost and 50% of the weight of an equivalent conventional enclosure. An insulation topology is also described.

Abstract: Systems and methods of detecting non-uniform aging and degradation of power assembly units are disclosed. The system may include a first power assembly unit and a second power assembly unit adjacent to the first power assembly unit. Each of the first and second power assembly units has a coupling capacitor and a number of electrical components. The system may further include a current sensor in between the coupling capacitors of the first and second power assembly units to detect a current spike in the coupling capacitors and the electrical components.

Abstract: A control module controls impedance injection units (IIUs) to form multiple connection configurations in sequence. Each connection configuration has one IIU, or multiple IIUs in series, parallel or combination of series and parallel. The connection configurations of IIUs are coupled to a high-voltage transmission line. The control module and the IIUs generate rectangular impedance injection waveforms. When the waveforms are combined and injected to the high-voltage transmission line, this produces a pseudo-sinusoidal waveform.

Abstract: A method for synchronized injection of impedance into high voltage (HV) transmission line is disclosed. The method includes generating, by a plurality of impedance injection units (IIUs) coupled to the HV transmission line, impedance injection waves that cumulatively form a pseudo-sinusoidal wave. The method further includes optimizing, by the plurality of IIUs, the pseudo-sinusoidal wave to represent a pure sinusoidal wave. The method further includes injecting, by the plurality of IIUs, the pseudo-sinusoidal wave, as impedance, into the HV transmission line. The plurality of IIUs form multiple connection configurations in sequence, each connection configuration comprising one IIU or multiple IIUs in series, parallel or combination thereof, coupled to the HV transmission line.

Abstract: Transients occur on power transmission lines for unpredictable reasons including breakers opening and closing, load variations, and inputs to the grid from renewable energy sources turning on and off. A recursive technique allows a linear function to be fitted to a non-linear grid dynamic of the power line transients. The technique is adaptive and helps to stabilize an impedance injection unit while it injects correcting impedance into a transmission line for the purpose of achieving power flow control. When applied to many injection units the technique may also help to stabilize the overall grid. The stabilization system using the recursive technique provides real-time monitoring of the associated power line and stabilization with respect to power line transients.

Abstract: A power flow control unit has one or more impedance injection units. The impedance injection unit has high current drivers and capacitors forming a capacitor bank, and a cooling plate. The cooling plate is thermally coupled to the high current drivers and thermally decoupled from the capacitor bank. Bus bars connect the impedance injection units in series with a power transmission line. The power flow control unit is configurable to inject into the power transmission line a reactive power of at least one MVAr (mega volt-ampere reactive).

Abstract: Flexible AC transmission system (FACTS) enabling distributed controls is a requirement for power transmission and distribution, to improve line balancing and distribution efficiency. These FACTS devices are electronic circuits that vary in the type of services they provide. All FACTS devices have internal circuitry to handle fault currents. Most of these circuits are unique in design for each manufacturer, which make these FACTS devices non-modular, non-interchangeable, expensive and heavy. One of the most versatile FACTS device is the static synchronous series compensator (SSSC), which is used to inject impedance into the transmission lines to change the power flow characteristics. The addition of integrated fault current handling circuitry makes the SSSC and similar FACTS devices unwieldy, heavy, and not a viable solution for distributed control. What is disclosed are modifications to FACTS devices that move the fault current protection external to the FACTS device and make them modular and re-usable.

Abstract: A system and method using thyristors to protect a series-connected Flexible AC Transmission Systems (FACTS) device from surge currents are disclosed. According to some embodiments, the system includes a thyristor connected in shunt with the FACTS device to be protected. The system further includes control circuitry coupled to the thyristor to drive a gate of the thyristor with a direct current (DC) signal and turn on the thyristor in a time span on order of microseconds. The system and method can be used to protect any series-connected FACTS device that is in danger of being exposed to surge current such as a reclose after a deadline.

Abstract: The presence of injected DC has harmful consequences for a power grid system. A piecewise sinusoidal ripple voltage wave at the line-frequency that rides on the main capacitor bank of the power converter is observed. This observation leads to a new DC detection elimination method. Three DC elimination methods for this ripple component are disclosed to allow dissipation of DC energy through heat and/or electromagnetic wave, or to allow transformation of this energy into usable power that is fed back into the power grid.

Abstract: A system and method using four switches connected in an H-bridge (full bridge) topology within a series-connected FACTS device is disclosed. System and method can be used to bypass a FACTS device. The switches in H-bridge are connected to an alternating current (AC) source allowing for various switching states, and enabling non-monitoring mode, local bypass monitoring mode, low-loss monitoring mode, and diagnostic mode of operation.

Abstract: A system enabling localized intelligent control with communication and coordination at local subsections of a power grid with information transfer to utility for supervisory control is disclosed. The disclosure extends the control and communication capability within, at the edge, and outside the edge of the power grid using intelligent and self-aware FACTS devices. Aspects of the disclosure enable control of a distribution network, energy storage systems and generation sources as an integrated system allowing optimization of power grid operation from generation to distribution. This control capability further enables a supervisory utility to implement and manage policy issues, such as standard compliance, carbon emission reduction, right-of-way management, and conformance to environmental regulations, such as EMI compliance, noise reduction, etc. This also allows the supervisory utility to optimize energy cost, network reliability, and asset utilization and life.

Abstract: 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.

Abstract: An enclosure includes a power flow control device to attach to a high voltage transmission line, a plurality of panels formed of metal, a shorting connection provided between each pair of panels, an electrical connection from at least one panel of the plurality of panels to the high voltage transmission line, a receiving region provided on each panel for each shorting connection, and an equipotential surface for reducing electromagnetic interference from the high voltage transmission line to internal components of the power flow control device, and from the internal components of the power flow control device to the high voltage transmission line.

Abstract: Methods and systems for protecting one or more flexible alternating current transmission system (FACTS) devices in a high voltage (HV) power transmission line are disclosed. The system may include a circuit breaker to de-energize the HV power transmission line when a fault current is detected on the HV power transmission line, and to determine whether the fault current has cleared. The system may further include a power supply to harvest energy from the fault current. The system may further include a bypass switch coupled to protect the FACTS devices by providing a controllable conduction path around the FACTS devices when the bypass switch is activated. And the system may further include a fault current harvesting circuit (FHC) and an actuator operating in conjunction to control the bypass switch based on the harvested energy.

Abstract: Disclosed is a reactance-injecting module used to balance the currents among the phases of polyphase electric power transmission lines or to manage power flow among alternate paths, where the reactance-injecting module has high-speed, dedicated communication links to enable the immediate removal of injected reactance from all phases of a phase balancing cluster when a fault is detected on any one of the multiple phases. The reactance-injecting module may communicate information on a detected fault to the other reactance-injecting modules of the phase balancing cluster within 10 microseconds after the fault is detected to allow the phase balancing cluster to eliminate injected reactance from all phases within 1 millisecond after the fault is detected. This provides extremely fast neutralization of injected reactance to minimize interference with fault localization analyses.

Abstract: A trailer-based system and related method are described for efficiently transporting, configuring and deploying a power flow control system, including connection to a power transmission line. The system may include preconfigured modules using bolted attachments, hoist rings and a corona ring structure. Standardized clamps are also used. A plurality of power flow control modules is operable while mounted on the trailer. The power flow control modules are configurable to inject reactive power into the power transmission line.