Smart Wires Inc.

Amrit Iyer

Haroon Inam

Debrup Das

Ali Farahani

Arthur Kelley

Govind Chavan

Antonio Ginart

David Munguia

Joe Carrow

Shreesha Adiga Manoor

Frank Kreikebaum

Hamed Khalilinia

Aaron Zhao

Niloofar Torabi

Mahsa Ghapandar Kashani

Liyu Cao

Brock Petersen

Vinod Babu

Zbigniew Wolanski

John Parks

Mark Sanders

Bryce Puchta

Andrew Moodie

Andrii Luchko

Abdul Rahman

Yuli Starodubstev

Volodymyr Strelchuk

Muhammad Fahad Ijaz

Kamil Bojanczyk

Shaiq Aman-ul-haq

Aaron Zhou

Guiping Zou

Joseph Innis Carrow

Qi Tang

Faisal Masood

Torabi Nioofar

Inan Haroon

Khalilinia Hamed

Chavan Govind

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.

Modular facts devices with external fault current protection

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.

Modular power converter with DC correction

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.

Powering an impedance injection unit during startup operations

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.

Clamping circuit for protecting FACTs

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.

Deployment of power flow control systems

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.

Power supply system responsive to high and low line currents

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.

Method for mounting high voltage capacitor banks

An apparatus for injecting impedance into a high voltage (HV) transmission line is disclosed. The apparatus comprises a plurality of modular flexible alternating current transmission systems (FACTS) based impedance injection units (IIUs), each modular FACTS based IIU without fault current protection. The apparatus further comprises a fault current protection module external to the modular FACTS based IIUs. The fault current protection module is coupled to the modular FACTS based IIUs to provide fault current protection to the modular FACTS based IIUs.

Modular FACTS devices with external fault current protection within the same impedance injection module

A driver circuit for driving a solenoid, and related method, are described. A power supply charges one or more capacitors to a high voltage level sufficient to over-drive the solenoid. A switch is connected to the one or more capacitors and the solenoid. When the switch is on, the switch connects the one or more capacitors to the solenoid. When the switch is off, the switch disconnects the one or more capacitors from the solenoid. Control circuitry turns the switch on, and turns the switch off in response to sensing current through the solenoid reaches a defined maximum current.

High speed solenoid driver circuit

A system architecture and method for enabling hierarchical intelligent control with appropriate-speed communication and coordination of control using intelligent distributed impedance/voltage injection modules, local intelligence centers, other actuator devices and miscellaneous FACTS coupled actuator devices is disclosed. Information transfer to a supervisory utility control is enabled for responding to integral power system disturbances, system modelling and optimization. By extending the control and communication capability to the edge of the HV power grid, control of the distribution network through FACTS based Demand response units is also enabled. Hence an integrated and hierarchical total power system control is established with distributed impedance/voltage injection modules, local intelligence centers, connected other actuator devices, miscellaneous FACTS coupled devices and utility supervisory all networked at appropriate speeds allowing optimization of the total power system from generation to distribution.

Dynamic and integrated control of total power system using distributed impedance injection modules and actuator devices within and at the edge of the power grid

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.

Protection from and filtering of disturbances for serial connected facts

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.

Detection and mitigation of DC injection on the power grid system

Modular FACTS devices with external fault current protection

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.

System and methods for using thyristors to conduct surge currents away from critical infrastructure

Growing community of inventors

Oakland, CA, United States of America

Amrit Iyer