Other

Indigo Energy, Inc.

David R Campbell

Christopher W Gabrys

A life counter that calculates and records the life utilized of the flywheel in a flywheel energy storage system and indicates when it should be removed from service, based on operational history instead of monitoring for symptoms of failure. The life counter can effectively monitor and measure any or all of the flywheel energy storage system parameters, such as the flywheel structural life, vacuum system life, bearing system life and electronics life. The life counter ensures safe operation of highly stressed flywheels by indicating when the safety margin for the flywheel is reached so that the flywheel energy storage system can be removal from service prior to encountering a risk of catastrophic failure. In some cases, failures may not be preceded by measurable warning symptoms, so removal from service at a calculated end of life would be desirable. The life counter can indicate that the flywheel system should be removed from service by several methods that include triggering an alarm, displaying a reading, altering operation or stopping operation. The life can be indicative of the flywheel structural life, as adjusted by a suitable safety factor, or electronics high power cycle life.

Life counter for flywheel energy storage systems

The invention, intended primarily for use in a steel flywheel power source (), provides a vacuum system and a method of maintaining a vacuum inside a flywheel chamber () for the life of the power source (). The vacuum system combines the use of cleaning and de-gassing treatments in the chamber () and vacuum tempering of the steel flywheel () with the use of a chemical type metal alloy nonevaporable getter, such as zirconium-vanadium-iron, that cooperatively matches the outgassing of the flywheel () and chamber () by sorbing those gases that are released. The getter may be reactivated throughout the life of the flywheel system by reheating it with an integral heater that is triggered by a timer instead of a vacuum gauge to increase the system reliability, using power taken directly from the energy stored in the flywheel. The electronics () of the flywheel power source are used to signal an alarm or prevent achieving or maintaining full speed of the flywheel when the vacuum in the chamber degrades.

Long-life vacuum system for energy storage flywheels

A flywheel uninterruptible power supply includes a solid steel cylindrical flywheel levitated for rotation about a vertical axis at tip speeds greater than 250 m/s on magnetic bearings in a low pressure housing. The cylindrical flywheel has a length L and a diameter D, wherein L/D&gE;1.0. A motor/generator attached to said flywheel accelerates the flywheel and maintains it at operating speed for storage of energy; and decelerates the flywheel for retrieval of the stored energy. The flywheel inertia section operates with a maximum stress of greater than 60% and less than 80% of the material yield stress when spinning at fully charged operating speed. The flywheel is constructed from steel with an ultimate strength greater 150 ksi and a toughness greater than 100 ksi (in)&Hat;1/2. The flywheel is a solid steel cylinder that is hardened to centerline structure throughout the axial thickness of the large diameter portion that is greater than 40% martensite. The flywheel is a solid steel cylinder that, in normal, fully charged operation, spins at a speed that would cause a fracture failure no sooner than one hundred thousand cycles between the fully charged normal operating speed and ten percent of that normal operating speed. The flywheel is free of flaws with length greater than &frac18;th inch at a diameter less than 20% of the outer diameter of the flywheel.

Uninterruptible power supply using a high speed cylinder flywheel

A flywheel energy storage system includes a housing adapted to be evacuated and maintained at a low pressure atmosphere, a cylindrical steel flywheel supported for low-loss rotation in the low pressure atmosphere within the housing on a bearing system, a nonevaporable getter for maintaining the low pressure atmosphere in the housing, and a motor/generator for accelerating and decelerating the flywheel for storing and retrieving energy. The motor/generator includes a rotor that is coupled to and rotates with the flywheel, and a stationary stator that cooperates with the rotor for converting between electrical and mechanical energy in the flywheel system and contains electromagnetic coils. The stator has a thin barrier coating for minimizing degradation of the low pressure atmosphere by minimizing outgassing from the stator into the housing.

Low outgas flywheel motor/generator

A flywheel energy storage system includes an energy storage flywheel supported for rotation about a substantially vertical axis on a combination bearing system comprised of a mechanical and a magnetic bearing. A motor and generator accelerates and decelerates the flywheel for storing and retrieving energy. The mechanical bearing is located at one axial end of the flywheel and provides axial downward force to the flywheel and is connected to the mechanical rolling element bearing using a low radial stiffness connecting element. The magnetic bearing is located at the axial end of the flywheel opposite the end with the mechanical bearing and provides axial upward force to support the weight of the flywheel, and also provides passive magnetic radial centering force to the flywheel.

Flywheel energy storage system with quill stabilizer

A flywheel power source having a flywheel supported by a bearing system for rotation inside an evacuated container. A brushless motor and generator is coupled to the flywheel for accelerating and decelerating the flywheel for storing and retrieving energy. The generator has a rotor coupled to the flywheel, and a stationary stator wound using multiple-strand individually insulated conductor wire coils. A heat energy transfer system passively cools the stator by heat transfer from the stator to an unpumped liquid coolant surrounding the coils and in intimate contact with the conductors in the coils. The stator is mounted in a stator coolant vessel that is partially filled with the coolant. The liquid coolant limits the maximum temperature of the coils during discharging of the flywheel power source.

Flywheel power source with passive generator cooling

A vacuum management and regeneration apparatus and method for operating an energy storage flywheel system having a flywheel supported by a bearing system inside an evacuated chamber enclosed within a container. A motor/generator stores and retrieves energy by accelerating and decelerating the flywheel. A vacuum is maintained in the container with a vacuum level sufficient to reduce the aerodynamic drag on the flywheel, typically between 10 Torr to 10 Torr depending on the flywheel construction and its operating tip speed. The vacuum management system, including a vacuum pump and a timer, maintains the vacuum level in the container. The timer periodically enables operation of the vacuum pump, such as a mechanical vacuum pump or a getter pump, to reduce the pressure in the container. A vacuum gauge can be used, periodically activated by the timer, to measure the internal vacuum; if the internal pressure is above a certain allowable level, the vacuum pump can be started or activated to restore the vacuum. If the vacuum gauge is omitted, the timer periodically activates the vacuum pump directly.

Growing community of inventors

Reno, NV, United States of America

David R Campbell