RU2802898C2 - Hydraulic system of stepless speed control with hydraulic and pneumatic speed control and method for its use - Google Patents

Abstract

FIELD: transport engineering.

SUBSTANCE: stepless speed control system has a turbine output shaft and an electric generator input shaft and contains a hydraulic system, a pneumatic system, a controller for controlling the electric generator output. The hydraulic system has hydraulic chambers connected to a turbine and an electric generator. The hydraulic chambers communicate with each other. The pneumatic system has pneumatic chambers connected to the turbine and electric generator and storage tank. The controller for controlling the output of the electric generator is connected to the input shaft of the electric generator. The engine output control method includes providing said hydraulic system for stepless speed control between the engine and the electric generator, and controlling the electric generator input shaft speed using a controller, a hydraulic system, and a pneumatic system.

EFFECT: improved control of the frequency of rotation of the transmission shaft.

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Description

TECHNICAL FIELD

The present invention relates to a system that uses a pneumatically assisted continuously variable transmission to control rotational speed at a micro-level and optimize the power generation of a turbine (wind or water) by evaluating the AC and load/line electrical characteristics after the entire power plant has generated power.

BACKGROUND OF THE ART

Continuously Variable Transmissions (CVT) are known and used in bicycles, automobiles, winches, hoists, power transmission, etc. There are many designs that have been developed for these devices, typical examples of which include pulleys with variable diameter with belts, toroidal or roller, friction, hydrostatic, ratchet, magnetic, etc.

Examples of US patents that relate to CVT include patent numbers 4,565,110, 4,970,862, 4,945,482, 4,922,717, 5,072,587, 4,916,900, 4,914,914, 4,850,192, and 4,838,024, each of which is incorporated herein by reference in its entirety. The prior art describes continuously variable speed transmission via pumps, pistons, gears, belts, pulleys, couplings or valves for macro-level control of output shaft speed for vehicles.

Another example of a CVT can be found in US Pat. No. 7,679,207, also included herein. This patent generally describes a system that includes a wind turbine, a CVT, a generator, and a CVT control. The wind turbine is described in great detail, while the CVT and tachometer are defined in general terms. Methods for controlling the continuously variable shaft speed transmission are carried out based on the pitch and deflection of turbine blades and through the implementation of a controller. In other words, the controller compensates for the CVT output speed by adjusting the turbine drive speed through the physical characteristics of the turbine itself. A wind turbine of any configuration has a drive shaft and this device can be considered as an engine. In general, a continuously variable transmission (CVT) provides a method of regulated speed transfer between an engine and a generator, with the generator producing electricity as a result of the operation of the wind turbine or engine.

However, there is a need for improvements to CVTs given their mechanically complex and expensive designs and limited control modes. To meet this need, the present invention provides an improved CVT.

DISCLOSURE OF THE INVENTION

The present invention provides an air-assisted hydraulic CVT that does not require pumps, gears, belts, pulleys, couplings or valves to vary the hydraulic fluid pressure for operation. One part of the operation control is done through a programmable logic controller or similar device or means that controls the output from the inverter output to the electrical load/line and then controls the system, including both the hydraulic and pneumatic aspects, to control the variable speed CVT for creating a source of electricity with a reactive balance and minimizing load instability.

The present invention also provides a pneumatic energy storage device for driving a generator when disconnected from a wind turbine to generate electricity under very low or very high wind conditions.

Features of the present invention include:

device with hydraulic continuously variable transmission (CVT) for macro-level speed adjustments;

pneumatic system for adjusting the CVT rotation speed at the micro level;

a method for accumulating pneumatic energy for direct drive of a turbine generator;

a pneumatic control method for a brake generator, and

a control system that measures the electrical characteristic of the alternating current output of the power system to the load/line, wherein the control system may activate a number of control valves to regulate the speed of the CVT at a micro level.

More specifically, the present invention includes both a continuously variable speed control hydraulic system and a method for using it. The system has a turbine output shaft and a generator input shaft. The system contains a hydraulic system having a first hydraulic chamber connected to the turbine output shaft, and a second hydraulic chamber connected to the electric generator input shaft. The first and second hydraulic chambers are in hydraulic communication with each other, and the first and second hydraulic chambers are designed to adjust the rotation speed of the electric generator input shaft at a macro level.

The system also has a pneumatic system having first and second pneumatic chambers. The first pneumatic chamber is connected to the turbine output shaft to create compressed air and store it in at least one storage tank. The second pneumatic chamber is connected to the electric generator input shaft and at least one storage tank for one or more of micro-adjustment of the electric generator input shaft speed, braking of the electric generator input shaft, and direct drive of the electric generator input shaft.

The system also includes a controller, wherein the controller monitors the output of an electric generator coupled to an input shaft of the electric generator, compares the output to the load/electrical distribution line, and adjusts the rotational speed of the electric generator shaft based on measurements of the load/electrical distribution line using one or more of a hydraulic system and a pneumatic system. systems for controlling the power supplied to the electrical distribution network.

The hydraulic system may comprise a plurality of hydraulically driven impellers, with at least one impeller coupled to a first hydraulic chamber and a plurality of impellers coupled to a second hydraulic chamber. Each impeller has an outlet and an outlet valve, the operation of the inlet and outlet valves being controlled by a controller.

The impellers in the second hydraulic chamber are of different sizes, preferably ranging in size from the smallest to the largest towards the electric generator, to increase or decrease the rotational speed of the electric generator input shaft. The hydraulic system also includes a reservoir in hydraulic communication with the first and second hydraulic chambers.

The pneumatic system includes at least one impeller connected to the first pneumatic chamber and at least one impeller connected to the second pneumatic chamber.

The invention also includes a method for controlling the output of a turbine, including providing the above-described hydraulic system for continuously variable speed control between the turbine and the electric generator, and controlling the rotation speed of the input shaft of the electric generator, the hydraulic system and the pneumatic system.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 depicts one embodiment of a turbine system for generating electric power through an energy control device that includes a CVT.

In FIG. 2 is a more detailed view of the CVT shown in FIG. 1, including features related to hydraulic macro speed control, pneumatic micro speed control, and CVT backup operations.

In FIG. 3 shows an example of the pneumatic and hydraulic module paddle wheel configuration for CVT shown in FIG. 1 and 2.

IMPLEMENTATION OF THE INVENTION

In FIG. 1 shows an embodiment of a system 700 that includes a turbine or wind engine 500, an integrated air-assisted hydraulic CVT 503, and a generator 505. The CVT 503 is located between the engine 500 and the generator 505. The CVT has shaft adapters 101A and 101B for connection to the engine 500 and the generator 505. respectively. A 501 tachometer can be added to operate the air safety brake if required.

The CVT has a series of hydraulic valves 216, 217, 226, 227, 236, 237, 246, 247, 256 and 257. These valves provide a selection of primary hydraulic chambers for speed control. Pneumatic control valves 306, 311, 314 and 319 are also provided and these valves provide auxiliary support for the CVT 503 speed control.

A hydraulic reservoir 290 is provided with a valve 291. The hydraulic reservoir 290 provides hydraulic fluid for operation. The system also includes a variety of pneumatic storage tanks, of which the 308 and 338 are two shown, but additional storage tanks can be provided if there is a need for more storage capacity. Pneumatic storage tanks 308 and 338 are designed for air handling operations using a variety of individual control valves, two of which are shown as 329, 339, to assist in supporting the CVT 503 and storing pneumatic energy for continuous power generation.

For safety purposes, each pneumatic storage tank 308 and 338 is provided with safety relief valves 330 and 340, respectively.

A system controller 502 is provided and located downstream of the converter/inverter 508. The controller 502 monitors the electrical output characteristics of the power generation system 700 relative to the load or electrical distribution network 510 to continuously regulate the operation of the power generation system 700.

In FIG. 2 shows in detail the integrated air-assisted hydraulic CVT 503. A shaft adapter 101A is attached to the engine 500 and provides a drive shaft 102 through an upper air chamber 350 and an upper hydraulic chamber 200.

Above the air chamber 350, a bevel gear 301 is provided which is attached to the drive shaft 102 to selectively operate an integral air compressor 303 located in the air chamber 350. The compressor 303 operates when the mating bevel gear 302, which is coupled to the shaft 304, and the bevel gear 301 are engaged. into engagement with pneumatic actuator 321, which is controlled by valve 322. Pneumatic energy is supplied to storage tank 308 through control valve 306 and port 307. This pneumatic energy may also be used to disengage actuator 321 and disengage gears 301 and 302. air flow occurs through hole 323 in the air chamber.

CVT 503 also includes hydraulic chambers 200 and 201, with chamber 200 being the primary source for supplying fluid. A system of hydraulic lines 204, 205, 214, 215, 224, 225, 234, 235, 244, 245, 254 and 255 pass through the hydraulic chambers 200 and 201, while each of the external hydraulic lines 206, 207 interconnects a number of control valves. 216, 217, 226, 227, 236, 237, 246, 247, 256 and 257. A vent valve 260 is provided at line 207 to release air. A reservoir valve 291 is provided for line 206, and this valve provides the ability to bypass hydraulic fluid to hydraulically disconnect engine 500 from generator 505.

Hydraulic chamber 200 has a main hydraulic impeller 202, which is located in an inner chamber 203. Impeller 202 propels hydraulic fluid at a rate based on turbine speed to selected auxiliary hydraulic actuators 212, 222, 232, 242, or 252, which are located in auxiliary hydraulic chamber 201. Hydraulic fluid is directed to one or more auxiliary hydraulic actuators depending on the choice of a pair of control valves 216/217, 226/227, 236/237, 246/247 or 256/257. The auxiliary hydraulic actuators are also impellers 212, 222, 232, 242, and 252, these impellers being located in inner chambers 213, 223, 233, 243, and 253, respectively. The size of the impellers 212, 222, 232, 242 and 252 is proportional to the increase or decrease in turbine speed required for the macro-operations of the generator 505 over a wide range.

An auxiliary air chamber 351 is provided and located between the generator and the auxiliary hydraulic chamber 201. The auxiliary air chamber 351 provides the ability to optimize the rotation speed of the generator 505 to minimize load imbalances or line 510. To increase the rotation speeds of the generator 505, compressed air is supplied from the storage tank 308 through port 310, while port 314 is used to reduce the rotation speeds of the generator 505. To control these macro speed control operations, control valves 311, 314, and 319 are provided and used. The auxiliary air chamber 351 includes a paddle wheel 317, which is located in the auxiliary air chamber 318. chamber 351. Impeller 317 provides a means for adjusting the speed of generator 505 in small increments so that control of the power supplied to load/line 510 occurs almost instantaneously. This allows you to control the stability and quality of the power supplied to the load/510 line.

The built-in air-assisted boost hydraulic CVT 503 can also be used to operate the generator 505 in conditions of no or minimal rotation of the engine/turbine 500. A series of storage tanks 338, etc., interfaced with the main storage tank 308, control the control valves 311, 314, 319, 320 and 329, which supply compressed air to the impeller 317, and control valves 260 and 291, which can shut off the hydraulic supply to the hydraulic chambers 200 and 201 to rotate the internal shaft 103, which in turn rotates the shaft generator 505 via coupling 101B to produce electricity at a controlled power corresponding to load/line 510.

In FIG. 3 provides details of a paddle wheel for use in the CVT 503. As described above, chamber 200 has a paddle wheel 202 and chamber 201 has paddle wheels 212, 222, 232, 242 and 252, with each paddle wheel located in its respective inner chamber 203. 213, 223, 233, 243 and 253. For example, impeller 202 includes a number of blades 209 that are at an angle of X degrees when axially rotated about the impeller 203. Around the inner chamber 203 at an angle of Y degrees when rotated about the axis are seals 210, creating four isolated regions during rotation of the impeller 202. One of the isolated regions is shown as "A", with two blades 209' and 209'' impinging on the seals 210' and 210''. The periods between wipes allow the impeller 202 to self-lubricate.

The inlet pipe 204 allows hydraulic fluid to enter the chamber as needed depending on the release of fluid from the impeller 202 through the tube 205 as the shaft 102 rotates. The fluid from the tube 205 enters the tube 206 and flows through the selected control valve 217, 227, 237, 247 or 257 to the corresponding impeller 212, 222, 232, 242 and 252, wherein the released liquid from the inner chamber 213, 223, 233, 243 and 253 is released through the outlets 214, 224, 234, 244 and 254 into the tube 207 through the selected interacting control valve 216, 226, 236, 246 and 256. Tube 207 returns fluid to main supply tube 204 of paddle wheel chamber 203 and paddle wheel 202 to complete the macro speed control hydraulic cycle in CVT 503. Typically, magnification factors are provided for this macro level and reducing the rotation speed by 2 and 3 times compared to the turbine speed.

The pneumatic aspect of the CVT 503 allows micro-level speeds to be set between macro-level speed ratios. More specifically, when the bevel gear 301 attached to the drive shaft 102 is engaged with the bevel gear 302 by the piston 304, the scroll or screw type air compressor 303 is driven in the presence of wind speeds. This allows atmospheric air to enter the inlet tube 323 in a compressed state and exit through the control valve 306 into the storage tank 308 through the opening 307. Compressed air can then be supplied from the storage tank 308 through the openings 310 and 311. The control valves 311 and 314 are reactivated to either reduce or dramatically increase the rotational speed of shaft 103 via paddle wheel 317. To allow the hydraulic system to make these micro-adjustments, release valve 260 and reservoir valve 291 are momentarily opened to provide pressure compensation. As the shaft speed of generator 505 increases, air pressure is released through exhaust valve 319. A decrease in shaft speed 103 occurs when control valve 314 is actuated and exhaust valve 319 is closed in pulse cycles so that compressed air in line 315 is directed back to the impeller. 317. The timing of these pulse cycles for micro-level speed control is generated by the controller 502 to match the AC electrical waveform of the load/line 510 to maximize power factors.

Two pneumatic chambers 350 and 351 allow the generator to be braked to a complete stop by fully opening the control valve/discharge valve 260 and reservoir valve 291 while closing all hydraulic control valves 216, 217, 226, 227, 236, 237, 246, 247, 256 and 257. Fluid then simply cycles from impeller 202 through reservoir 290 as pneumatic control valve 314 opens and 319 closes, creating back pressure to stop rotation of shaft 103.

The plurality of pneumatic storage tanks 308, 338,... may also supply stored pneumatic energy to rotate the shaft 103 and drive the generator 505 when there is no wind to drive the turbine 500. In this mode, the control valve/outlet valve 260 and the reservoir valve 291 is fully open and all hydraulic control valves 216, 217, 226, 227, 236, 237, 246, 247, 256 and 257 are closed. In this operating state, the hydraulic system is in neutral. Control valves 311 and 319 can then be opened and this allows pneumatic energy to drive the impeller 317, causing the shaft 103 to rotate at the proper speed to drive the generator 505 to match the load/mains AC electrical waveform 510.

The system and method of the present invention provides a much improved method for taking rotation of a motor shaft, such as a wind turbine, and transmitting that rotation to a generator with speed control at both the macro and micro levels. The present invention also allows the engine to be either disconnected from the generator or the generator to be operated while the engine is not rotating or is rotating at a low level.

The invention, as such, has been described in terms of preferred embodiments thereof, which satisfy any and all objects of the present invention as stated above and provide a new and improved system for generating power using an engine, CVT and generator and a method for using it.

Of course, those skilled in the art may contemplate various changes, modifications, and alternative embodiments of the teachings of the present invention within its stated spirit and scope. It is intended that the present invention be limited only by the terms of the appended claims.

Claims (11)

1. A system for stepless speed control, having a turbine output shaft and an electric generator input shaft, containing: - a hydraulic system having a first hydraulic chamber connected to the output shaft of the turbine, and a second hydraulic chamber connected to the input shaft of the electric generator, the first and second hydraulic chambers are hydraulically connected to each other, and the first and second hydraulic chambers are designed to adjust the rotation speed of the input shaft electric generator at the macro level; - a pneumatic system having a first pneumatic chamber connected to the output shaft of the turbine for creating compressed air and storing it in at least one storage tank, a second pneumatic chamber connected to the output shaft of the electric generator and at least one storage tank for one or more of adjusting the rotation speed at the macro level, braking the output shaft of the electric generator and direct drive of the input shaft of the electric generator, and - a controller for monitoring the output of an electric generator coupled to the input shaft of the electric generator, comparing the output to the load/distribution line, and adjusting the rotational speed of the electric generator shaft based on load/distribution line measurements using one or more of a hydraulic system and a pneumatic system to control power supplied to the power distribution network. 2. The system of claim 1, further comprising a plurality of hydraulically actuated impellers, wherein at least one impeller is coupled to the first hydraulic chamber and a plurality of impellers are coupled to the second hydraulic chamber, each impeller having an inlet and an outlet valve, and the operation of the inlet and outlet valves is controlled by the controller. 3. The system according to claim 2, in which the impellers in the second hydraulic chamber are of different sizes. 4. The system of claim 3, wherein the size of the impellers in the second hydraulic chamber varies in a range of sizes from the smallest to the largest towards the electric generator to increase or decrease the rotation speed of the input shaft of the electric generator. 5. The system according to claim 1, further comprising a reservoir in communication with the first and second hydraulic chambers. 6. The system of claim 1, wherein the pneumatic system comprises at least one impeller coupled to the first pneumatic chamber and at least one impeller coupled to the second pneumatic chamber. 7. A method for controlling the output of an engine, including providing a continuously variable speed control hydraulic system according to claim 1 between the engine and the electric generator, and controlling the rotation speed of the input shaft of the electric generator using a controller, a hydraulic system and a pneumatic system. 8. The method according to claim 1, wherein the engine is a wind turbine.

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