Abstract: A voltage source converter may be coupled to a transmission line. The voltage source converter has two or more inverter valve units. Each inverter valve unit has a full H bridge of switching devices and a capacitor. Paralleling conductor pairs connect the inverter valve units in parallel, in a self-balancing circuit arrangement.

Abstract: A solenoid driver operable to drive a solenoid actuating a high-voltage power switch is disclosed. The solenoid driver includes a first group of semiconductor switches including a first semiconductor switch and a second semiconductor switch in series. This group is connected to a high-voltage supply line by a diode. The solenoid driver further includes a second group of semiconductor switches including a third semiconductor switch and a fourth semiconductor switch in series. This group is connected to the high-voltage supply line by a second diode. The solenoid driver further includes a common connection between the first group of semiconductor switches and the second group of semiconductor switches. A solenoid coil of the solenoid is connected between the first group of semiconductor switches and the second group of semiconductor switches at a junction between the first and second semiconductor switches and a junction between the third and fourth semiconductor switches.

Abstract: A system for managing power delivery and power flow in a distribution grid having grid forming capability is disclosed. The system includes a connect-disconnect switches operable to connect a power transmission grid to and disconnect the power transmission grid from the distribution grid. The distribution grid includes renewable energy generators and a number of loads. The system further includes a full bridge shunt inverter system connected to the distribution grid. The full bridge shunt inverter system includes a four-quadrant DC-to-AC inverter and at least a battery for power storage and operable as a power source for grid formation. The system further includes a pair of active filters connected in series on the distribution grid. The full bridge shunt inverter system is connected to the distribution grid at a node between the active filters to enable impedance adjustment for managing and controlling the power flow in the distribution grid.

Abstract: A multi-mode power supply is described for providing power to an impedance injection unit that is operable to inject reactive power into a power transmission line. The impedance injection unit is configured to operate safely in the presence of switching states of the impedance injection unit, and in the presence of disturbances such as surge currents in the power transmission line, by the multi-mode power supply clamping a potential overvoltage to a safe level. The power supply contains analog and digital circuits and can recover automatically from a surge current in the transmission line, or from a condition of zero line current. Power harvesting may be achieved via a line connected current transformer, via an internal current transformer, via a DC link capacitor, or from combinations of these.

Abstract: A liquid cooling power flow control system and related method are described. The system has switching assemblies for power flow control, in an enclosure. A pump circulates liquid coolant through a liquid cooling block to each switching assembly. The switching assemblies are electrically isolated from the enclosure.

Abstract: A power flow control system and method relate to power flow control for faults on power transmission lines. An inverter has power switching devices and a capacitor. A power-safe circuit holds the power switching devices inactive during an initial fault current of the power transmission line, until a power supply for operating the inverter reaches a threshold.

Abstract: A series connectable power flow module is for connection to a power transmission line. The module has a full bridge inverter and a controller. The full bridge inverter has inputs for controlling charging and discharging a DC link capacitor. The controller is coupled to the inputs of the full bridge inverter. The controller is configured to separate a harmonic current from a line current flowing in the power transmission line. The controller operates the full bridge inverter in accordance with the separated harmonic current, to attenuate the harmonic current flowing in the power transmission line through injection of a DC link capacitor voltage.

Abstract: Intelligent impedance injection modules (IIM)s are currently being used for line balancing and overcoming local disturbances on High Voltage (HV) transmission lines of an HV power grid. These distributed IIMs are connected and/or coupled to the HV transmission lines and operate with a pseudo ground at the voltage of the HV transmission line. In order to operate effectively, the IIMs need to communicate with other distributed IIMs across the three phases of the HV grid and also communicate with local intelligent centers LINCs that connect to and synchronize operations across each group of the distributed IIMs in a local region of the HV power grid. Systems and methods are presented for effective and secure sub-cyclic speed communication to and from the distributed IIMs, distributed IIMs to LINCs and substations to enable coordinated actions. Further the distributed IIMs and LINCs receive GPS signals and use the GPS clock for synchronizing operations.

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: 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: A clamping circuit employs a filter comprising two series branches of surge arresting circuits to clamp voltage spikes on equipment in series with a power transmission line. Clamping of these voltage spikes protects insulators, semiconductors, and other sensitive components within the series equipment from transient grid events. By using a predetermined frequency to control the response, the filter does not interfere with normal operation of the power system nor the operation of a power flow control module series-coupled to the transmission line through the filter. The clamping circuit employs hysteresis and imposes a shared voltage ratio between the two circuit branches, the ratio depending on frequency and voltage of the transient asserted on the transmission line, in order to provide a very sharp protection response to events within the target frequency range.

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.

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: A power supply system is operable to harvest power at low and high line currents. A current transformer is arranged to couple to a power transmission line. A current sensor which may be a Rogowski coil is arranged to couple to the power transmission line. Branches of power supply circuitry are connected to a plurality of secondary windings of the current transformer. A control circuit selects one of the branches of power supply circuitry, depending on sensed magnitude of line current, to provide electrical power to an output capacitor. Sufficient stored energy is also provided for performing a backup of operating parameters when the line current reduces to zero.

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: A capacitor bank assembly has a conductive mount tray and capacitors. The capacitors are vertically mounted and held by the conductive mount tray. All positive terminals of the capacitors are connected to a first conductive plate. All negative terminals of the capacitors are connected to a second conductive plate. An insulating material separates the first conductive plate and the second conductive plate.

Abstract: A fault detection system has line current monitors. Each line current monitor couples to a line-phase of an electric power transmission system. Each line current monitor has a phase detector, a loop filter and a controlled oscillator, coupled as a phase locked loop. The phase detector has a rotating frame transform. The phase detector couples to a line-phase and provides in-phase and quadrature signals in a rotating frame, based on in-phase and quadrature signals proportional to current in the line-phase. One or more fault detection modules are coupled to the line current monitors through inter-phase communication of the in-phase and quadrature signals in a time frame rotating at the line frequency. The communication may have electrical isolation.

Abstract: A liquid cooling static synchronous series compensator (SSSC) system has inverter valve modules, inverter valve units and liquid cooling blocks. Liquid cooling blocks may be configured to provide a jetted flow, a parallel flow or an individualized flow, within an enclosed fluid chamber, for cooling inverter valve units. Liquid cooling blocks may have voltage isolation.

Abstract: An impedance injection unit (IIU) system is coupled to a high-voltage (HV) transmission line. The IIUs are activated in sequences of activation in successive time periods. This injects an impedance waveform onto the HV transmission line. The ordering of IIUs in the sequences of activation is repeatedly changed in successive time periods. This equalizes electrical stress across the IIUs used, leading to overall improvement in IIU system lifetimes.

Abstract: Disclosed is a reactance-injecting module and its method of use 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 or reduction 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 a time that is short compared to a cycle of the alternating current, such as 1 millisecond after the fault is detected. This provides extremely fast neutralization of injected reactance to minimize interference with fault localization analyses.