Patent Application
20160010704
Uninterruptible power supplies, also known as uninterruptible power sources (UPS) are electrical apparatuses known in the art that provide emergency power to a load when the input power source, typically mains power, fails. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide near-instantaneous protection from input power interruptions, by supplying energy stored in batteries, supercapacitors, or flywheels. The on-battery runtime of most uninterruptible power sources is relatively short (only a few minutes) but sufficient to start a standby power source or properly shut down the protected equipment. A UPS is typically used to protect hardware such as industrial equipment, computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption or data loss. UPS units range in size from units designed to protect a single computer without a video monitor (around 200 volt-ampere rating) to large units powering entire data centers or buildings.
Rotary Flywheel UPS systems used in mission critical facilities provide very limited time to transition to back up generators after a power loss usually 15 to 45 seconds depending on the load. Theoretically, this “ride through” should be adequate to allow the backup generators to start. In the event that the backup generators fail to start, there is no time for an orderly shutdown of the systems. Costs associated with power failures are significant, and may collectively (billions of dollars annually). As an example, banks where millions of transactions are taking place every minute are exposed to significant losses during a power failure. Most mission critical facilities will install battery backup in order to provide adequate time for orderly shutdowns and to ensure that there is adequate time to get the backup generators started. Battery backup used to provide power to critical systems for an extended period of time is often expensive, requires dedicated space with special ventilation and fire protection systems, requires maintenance and is environmentally unfriendly among other things.
In one exemplary embodiment, an apparatus/system is disclosed for providing supplementary power, where the apparatus includes a vessel, configured to receive and contain fluid, a piston, configured within the vessel to be displaced by the fluid and provide pressure from the displacement, a fluid supply line, operatively coupled to an output of the vessel, a solenoid valve, operatively coupled to the fluid supply line; and a flywheel power supply, operatively coupled to the valve, wherein the flywheel power supply comprises a flywheel and a hydraulic drive adapter. The apparatus is configured to receive a signal indicating a power outage, the valve being further configured to open in response to the signal and provide fluid pressurized by the piston to the hydraulic drive adapter and cause the flywheel to operate and provide the supplementary power. The fluid may comprise at least one of an oil-based and water-based hydraulic fluid.
In other exemplary embodiments, the apparatus/system may further comprise a fluid reservoir and a hydraulic pump, wherein the hydraulic pump is configured to pump fluid from the fluid reservoir to the vessel. The fluid reservoir may be operatively coupled to the hydraulic drive adapter and configured to receive fluid discharged from the hydraulic drive adapter. The apparatus may further comprise a check valve operatively coupled between the hydraulic pump and the vessel via the fluid supply line, wherein the check valve may be configured to directionally control flow of fluid to the vessel. The apparatus may still further comprise a pressure regulator valve, operatively coupled to the solenoid valve, wherein the pressure regulator valve is configured to regulate pressure provided by the piston in the fluid supply line.
In other exemplary embodiments, a method is disclosed for providing supplementary power, wherein the method comprises the steps of receiving and containing hydraulic fluid in a vessel comprising a piston, positioned within the vessel, wherein the weight of the piston provides a pressure for the fluid in the vessel, and wherein the vessel is operatively coupled to a fluid supply line. The method may further comprise the steps of receiving a signal indicating a power outage, wherein receipt of the signal causes a solenoid valve to open and allow flow of fluid from the vessel to a hydraulic drive adapter of a flywheel power supply, and wherein the flow of fluid in the hydraulic drive adapter causes a flywheel of the flywheel power supply to operate and provide the supplementary power.
In other exemplary embodiments, the method comprises the steps of receiving fluid in the vessel comprises pumping fluid from a fluid reservoir, via a hydraulic pump, to the vessel. Fluid discharged from the hydraulic drive adapter may be received in the fluid reservoir. Fluid to the vessel may be directionally controlled via a check valve operatively coupled between the hydraulic pump and the vessel.
In still further embodiments, an apparatus/system is disclosed for providing supplementary power, comprising a vessel, configured to receive and contain hydraulic fluid, the vessel comprising a piston configured within the vessel to be vertically displaced by the hydraulic fluid and provide pressure from the weight of the piston to a fluid supply line. A solenoid valve may be operatively coupled to the fluid supply line. The apparatus may further include a flywheel power supply comprising a flywheel and a hydraulic drive adapter, wherein the hydraulic drive adapter is operatively coupled to the solenoid valve via the fluid supply line. The apparatus may be configured to receive a signal indicating a power outage, the solenoid valve being further configured to open in response to the signal and provide the hydraulic fluid pressurized by the piston to the hydraulic drive adapter and cause the flywheel to operate and provide the supplementary power.
In other exemplary embodiments, the apparatus/system may comprise a fluid reservoir and a hydraulic pump, wherein the hydraulic pump is configured to pump hydraulic fluid from the fluid reservoir to the vessel. The fluid reservoir may be operatively coupled to the hydraulic drive adapter and configured to receive hydraulic fluid discharged from the hydraulic drive adapter. A check valve may also be operatively coupled between the hydraulic pump and the vessel via the fluid supply line, wherein the check valve is configured to directionally control flow of fluid to the vessel. A pressure regulator valve may be operatively coupled to the solenoid valve, wherein the pressure regulator valve is configured to regulate pressure provided by the piston in the fluid supply line. The vessel may further comprise a sensor configured to sense an amount of hydraulic fluid in the vessel and provide a signal to the hydraulic pump to modify operation based on the sensed amount.
Further scope of applicability of the present disclosure will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
The figures and descriptions provided herein may have been simplified to illustrate aspects that are relevant for a clear understanding of the herein described devices, systems, and methods, while eliminating, for the purpose of clarity, other aspects that may be found in typical devices, systems, and methods. Those of ordinary skill may recognize that other elements and/or operations may be desirable and/or necessary to implement the devices, systems, and methods described herein. Because such elements and operations are well known in the art, and because they do not facilitate a better understanding of the present disclosure, a discussion of such elements and operations may not be provided herein. However, the present disclosure is deemed to inherently include all such elements, variations, and modifications to the described aspects that would be known to those of ordinary skill in the art.
Turning to
As vessel 102 is filled with hydraulic fluid, the weight of piston 101 provides a counter-pressure within vessel 102. When vessel 102 is completely filled, the piston 101/vessel 102 may be considered at a maximum pressure. A hydraulic fluid supply line 103 is preferably coupled to a solenoid valve 104 which should be configured to be naturally in a “closed” state. In one embodiment, solenoid valve 104 is operatively coupled to a power system configured to provide a signal (PWR) indicating that power has failed, and that back-up power from system 100 is required. In one embodiment, solenoid valve 104 may be held in a closed position via a continuous PWR signal, indicating that power in a primary system is operating normally. Once power in the main system turns off, the PWR signal is no longer being received, causing solenoid valve 104 to open. As a result, the pressure from piston 101 causes fluid in vessel 102 to flow through valve 104 and pressure regulator valve 105 and into flywheel rotary UPS 106.
In one embodiment, UPS 106 operates under flywheel energy storage principles by accelerating a rotor, such as flywheel 108 via hydraulic drive adapter 107 to a very high speed and maintaining the energy in the system as rotational energy. When energy is extracted from the system, the flywheel's rotational speed may be reduced as a consequence of the principle of conservation of energy; adding energy to the system correspondingly results in an increase in the speed of the flywheel.
In a simplified embodiment, UPS 106 may comprise a rotor suspended by bearings inside a vacuum chamber to reduce friction, connected to a combination electric motor and electric generator. The flywheel may be a large steel flywheel rotating on mechanical bearings. In one embodiment, the flywheel may comprise carbon-fiber composite rotors that have a higher tensile strength than steel and are an order of magnitude less heavy. Magnetic bearings may be used used instead of mechanical bearings, to reduce friction. In one embodiment, high-temperature superconductor (HTSC) bearings or hybrid bearings may be used, where permanent magnets support a load and high-temperature superconductors are used to stabilize it. Superconductors may be advantageous in stabilizing a load because they may operate as diamagnets. If the rotor tries to drift off center, a restoring force due to flux pinning (magnetic stiffness of the bearing) restores it. Since flux pinning is a factor for providing the stabilizing and lifting force, the HTSC can be made much more easily for flywheel energy storage than for other uses. HTSC powders can be formed into arbitrary shapes so long as flux pinning is strong.
Compared with other techniques for storing electricity, flywheel energy storage systems have long lifetimes (lasting decades with little or no maintenance. Full-cycle lifetimes for flywheels may range from in excess of 105, up to 107, cycles of use), and provide high energy density (100-130 W·h/kg, or 360-500 kJ/kg), and large maximum power output. The energy efficiency (ratio of energy out per energy in) of flywheels can be as high as 90%. Typical capacities may range from 3 kWh to 133 kWh.
The energy density of flywheel 108 may vary, depending on the rotor geometry used and the properties of material being used. For single-material, isotropic rotors, this relationship may be expressed as
where E is the kinetic energy of the rotor (J), m is the rotor's mass (kg), K is the rotor's geometric shape factor, σ is the tensile strength of the rotor material (Pa) and ρ is the material's density (kg/m3).
Continuing with the example of
The embodiment of
Turning to
The exemplary system 200 of
As vessel 102 is filled with hydraulic fluid, the weight of piston 101 provides a counter-pressure within vessel 102. When vessel 102 is completely filled, the piston 101/vessel 102 may be considered at a maximum pressure. A hydraulic fluid supply line 103 is preferably coupled to solenoid valves 104, 112 which may be configured to be naturally in a “closed” state. In one embodiment, solenoid valves 104, 112 are respectively coupled to a power system configured to provide a signal (PWR) indicating that power has failed, and that back-up power from system 200 is required. In one embodiment, solenoid valves 104, 112 may be held in a closed position via a continuous PWR signal, indicating that power in a primary system is operating normally. Once power in the main system turns off, the PWR signal is no longer being received, causing solenoid valves 104, 112 to open. As a result, the pressure from piston 101 causes fluid in vessel 102 to flow simultaneously through valves 104, 112 and pressure regulator valves 105, 113 and respectively into flywheel rotary UPS 106, 112.
Similar to the embodiment of
In the embodiment of
Turning to
As vessels 102, 121 are filled with hydraulic fluid, the weight of pistons 101, 120 provide a counter-pressure within vessels 102, 121. When vessels 102, 121 are completely filled, the respective piston weight may provide a maximum pressure. A hydraulic fluid supply line 103 is preferably coupled to both vessels 102, 121 and a solenoid valve 104 which should be configured to be naturally in a “closed” state. In one embodiment, solenoid valve 104 is operatively coupled to a power system configured to provide a signal (PWR) indicating that power has failed, and that back-up power from system 100 is required. In one embodiment, solenoid valve 104 may be held in a closed position via a continuous PWR signal, indicating that power in a primary system is operating normally. Once power in the main system turns off, the PWR signal is no longer being received, causing solenoid valve 104 to open. As a result, the pressure from pistons 101, 120 cause fluid in vessels 102, 121 to flow through valve 104 and pressure regulator valve 105 and into flywheel rotary UPS 106.
In one embodiment, vessels 102, 121 may operate to provide hydraulic fluid simultaneously. In another embodiment, vessels may be designated as “primary” (e.g., 102) and “secondary” (e.g., 121) vessels, and wherein the secondary vessel is equipped with its own solenoid (not shown). Each vessel may be equipped with sensors, similar to the embodiment of
Continuing with the embodiment of
In a simplified embodiment, UPS 106 may comprise a rotor suspended by bearings inside a vacuum chamber to reduce friction, connected to a combination electric motor and electric generator. The flywheel may be a large steel flywheel rotating on mechanical bearings. In one embodiment, the flywheel may comprise carbon-fiber composite rotors that have a higher tensile strength than steel and are an order of magnitude less heavy. Magnetic bearings may be used instead of mechanical bearings, to reduce friction. In one embodiment, high-temperature superconductor (HTSC) bearings or hybrid bearings may be used, where permanent magnets support a load and high-temperature superconductors are used to stabilize it.
Hydraulic fluid entering UPS 106 at a predetermined pressure specified by regulator valve 105 causes hydraulic drive adapter 107 to operate flywheel 108 for generating power (OUT) back to the main power system. In one embodiment, hydraulic fluid exiting UPS 106 is fed back to fluid reservoir 109, which regenerates the fluid for future use in vessel 102 via hydraulic pump 110.
In the above configurations, the flywheel UPS may be configured to continuously rotate by getting power from the grid. Accordingly, the output power is advantageously protected from power distortions from the grid. In an alternate embodiment, power may be provided to the flywheel UPS and to the pump. In such a configuration, the power to the UPS is continuous, and the power to the pump is only needed after power is restored, where the pump is utilized to refill and re-pressurize the vessel. As the pump is continuously running, this would cause the flywheel to rotate, which in turn may vitiate the need for a power supply to the flywheel UPS. Such a configuration would be advantageous in reducing installation costs.
In the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
