Abstract: An apparatus and methods of opening and closing a vacuum switched link are disclosed. The apparatus includes a vacuum interrupter including a mechanical coupling and a moving contact. The apparatus further includes a drive rod, where the mechanical coupling is disposed between the drive rod and the moving contact. The apparatus further includes a direct-acting closing spring coupled to the drive rod. The apparatus further includes a reset spring coupled to the drive rod. The apparatus further includes an armature slidably coupled to the drive rod and responsive to the reset spring during closing of the vacuum interrupter. The apparatus further includes a coil embedded in the armature.

Abstract: A flexible alternating current transmission system (FACTS)-based shunt system is described for use in a hierarchy in a high-voltage or medium-voltage power grid. The shunt system includes a FACTS-based shunt device, a communication link, and a shunt controller. A hierarchy in the power grid includes a supervisory utility communicably coupled to localized intelligence centers (LINCs). Each LINC is communicably coupled to one or more impedance injection modules (IIMs) that are coupled to the power grid. The hierarchy has an optimization engine. The shunt controller, of the shunt system, is to communicate and cooperate with one or more of the LINCs in the hierarchy. The shunt controller is to operate the FACTS-based shunt device in accordance with such communication and cooperation with the LINCs, to provide voltage stability to the power grid through hierarchical control according to the supervisory utility, the LINCs and the optimization engine.

Abstract: A system has grid forming capability. A connect-disconnect switch is connectable to a power transmission grid and connectable to a distribution grid that may have renewable energy generation sources and loads. A shunt inverter system comprising a 4-quadrant DC-to-AC inverter and a battery power source is connectable to the distribution grid. A controller controls the connect-disconnect switch to connect and disconnect the distribution grid from the power transmission grid, or disconnect a first segment of the distribution grid from a second segment of the distribution grid. The controller operates the shunt inverter system to provide power factor correction to the distribution grid under normal operation. The controller operates the shunt inverter system with switching and current control instructions to enable grid forming and sustaining of continued operation of the distribution grid.

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 power supply module harvests power at low and high line currents of a power transmission line. The power supply module uses a current transformer, which may power controllers. The current transformer has a single turn primary winding, which can be coupled to a power transmission line, and a single secondary winding connected to the power supply module.

Abstract: A modular power converter is operable to mitigate a DC component of injection onto a power transmission line. The modular power converter includes a pulse width modulation (PWM)-controlled generator, a voltage emulator, and a control circuit. The PWM-controlled generator includes drivers and a coupling capacitor. The PWM-controlled generator is to store voltage on the coupling capacitor and inject a voltage of the converter, which includes the DC component of injection, onto the power transmission line. The voltage emulator is to determine a DC measurement emulating the voltage of the converter, as a time-varying average value that is based on summing generator driver-state weighted values of the voltage on the coupling capacitor. The control circuit is to generate PWM pulses to operate the PWM-controlled generator and adjust timing of the PWM pulses, based at least on the DC measurement from the voltage emulator to counter-balance the DC component of injection.

Abstract: A power flow control system is disclosed. The system includes impedance injection modules (IIMs) distributed along and connected in series to one or more power transmission lines. The system further includes dual-ring fiber optic networks, with each dual-ring fiber optic network including a pair of fiber rings that provide data flow in opposite directions. The system further includes redundant power line coordinators in communication with the IIMs through the dual-ring fiber optic networks.

Abstract: A liquid cooling static synchronous series compensator (SSSC) system with series connected inverter valve modules that have liquid cooling blocks is described. The inverter valve modules are operable to inject reactive power into a power transmission line. Inverter valve units are attached to liquid cooling blocks, where there is direct impingement of liquid coolant on an exposed portion of an inverter valve unit in an enclosed fluid chamber. Each liquid cooling block has voltage isolation relative to other liquid cooling blocks. Such voltage isolation may limit ionization of liquid coolant in an SSSC system operating in proximity to high voltages.

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 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.