摘要:
A hydraulic transmission comprises a variable displacement hydraulic pump and a variable displacement hydraulic motor, connected by high and low pressure lines. One of the hydraulic pump and the hydraulic motor has a discontinuous range of displacements. The other has a continuous range of displacements. In order to allow a continuous range of input and output torques, despite the discontinuous range of displacements, the pressure in a high pressure line is varied. This enables a hydraulic pump or motor which has a discontinuous range of displacements but other technical advantages, such as reduced torque ripple, to be employed without losing fine control of input and output torque. The hydraulic transmission is useful for a wind turbine where the turbine drives a hydraulic pump operated with a discontinuous range of displacements.
摘要:
A hydraulic transmission comprising a variable displacement pump and motor, at least one having cylinders having valves which are controllable on each cycle of cylinder working volume to determine the net displacement of working fluid by the cylinder. The transmission has a valve control module which determines a displacement of the pump and the motor by specifying a displacement demand. The pump and/or motor valve control module determine the frequency of intensity peaks in the frequency spectrum of the pattern of cylinders carrying out active and inactive cycles of cylinder working volume using a first procedure and, if these will fall within disallowed frequency bands including the resonant frequency of components with which the transmission is in mechanical communication, the displacement demand, or another input, is periodically modified to suppress generation of those frequencies. The hydraulic transmission is useful for example in a wind turbine generator, or a vehicle.
摘要:
It is intended to provide a power generating apparatus of renewable energy type and an operation method of the power generating apparatus, which can achieve both variable speed operation and grid connection without a frequency converting circuit and which uses a hydraulic transmission. In the power generating apparatus of renewable energy type 1, renewable energy received via a blade 4 is transmitted to a synchronous generator 20 via a rotating shaft 8 and a hydraulic transmission 10. The synchronous generator 20 is driven by a hydraulic motor 14 of the hydraulic transmission 10 to generate power. The synchronous generator 20 is connected to a grid without a frequency converting circuit and the power generated by the synchronous generator 20 is supplied to the grid 50. The power generating apparatus 1 is also provided with a transmission controller 40 which controls the hydraulic transmission 10. The transmission controller 40 controls the hydraulic transmission 10 in a normal operation mode to adjust displacement of each of a hydraulic pump 12 and the hydraulic motor 14 such that the rotating shaft 8 rotates at a rotational speed that is variable with respect to flow speed of the renewable energy while keeping a rotational speed of the synchronous generator 20 at a synchronous speed based on frequency of the grid 50 during normal operation of the power generating apparatus.
摘要:
A power generating apparatus includes a rotating shaft, a hydraulic pump driven by the rotating shaft, a hydraulic motor driven by pressurized oil supplied from the hydraulic pump, and a generator coupled to the hydraulic motor. Each of the hydraulic pump and motor includes working chambers each defined by a cylinder and a piston, a high pressure manifold and a low pressure manifold. Each of the high and low pressure manifolds includes branch channels connected to the working chambers and a merging channel connected to a high or low pressure oil line. The branch channels are equipped with high or low pressures valves, joined together and merged into the merging channel.
摘要:
A wind turbine generator (100), or other energy extraction device, has a hydraulic circuit comprising a hydraulic pump (129) driven by a rotating shaft (125) and a hydraulic motor (131) driving an electricity generator (157), or other load. A high pressure manifold (133) extending between the pump and motor is in communication with an accumulator (145, 147, 149). A controller receives a control signal and regulates the displacement of working fluid by the hydraulic pump and the hydraulic motor relative to each other. Thus, power input through the rotating shaft and output to the load can be decoupled for at least a period of time and the energy output of energy extraction device can be varied, for example to smooth the total power output to an electricity grid (101), without compromising power input. A group of energy extraction devices can be controlled in concert to maximise power input while providing smooth power output. Individual electricity generators in different energy extraction devices can be switched on and off in concert to provide smooth power output while benefiting from the reduced energy losses that can be obtained by switching off electricity generators where possible.
摘要:
A hydraulic transmission comprises a variable displacement hydraulic pump and a variable displacement hydraulic motor, connected by high and low pressure lines. One of the hydraulic pump and the hydraulic motor has a discontinuous range of displacements. The other has a continuous range of displacements. In order to allow a continuous range of input and output torques, despite the discontinuous range of displacements, the pressure in a high pressure line is varied. This enables a hydraulic pump or motor which has a discontinuous range of displacements but other technical advantages, such as reduced torque ripple, to be employed without losing fine control of input and output torque. The hydraulic transmission is useful for a wind turbine where the turbine drives a hydraulic pump operated with a discontinuous range of displacements.
摘要:
It is intended to provide a power generating apparatus of renewable energy type which obtains desired torque rapidly in response to changes of the renewable energy as well as a method of operation such an apparatus. The power generating device which generates power from a renewable energy source, includes a rotating shaft 8 driven by the renewable energy, a hydraulic pump 12 of variable displacement type driven by the rotating shaft 8, a hydraulic motor 14 driven by pressurized oil supplied from the hydraulic pump 12, a generator 20 coupled to the hydraulic motor 14, a high pressure oil line 16 through which a discharge side of the hydraulic pump 12 is in fluid communication with an intake side of the hydraulic motor 14, a pump demand determination unit 44 which determines a displacement demand Dp of the hydraulic pump based on a target torque Td of the hydraulic pump 12 and an oil pressure in the high pressure oil line 16 and a pump controller 46 which adjusts displacement of the hydraulic pump 12 to the determined displacement demand Dp.
摘要:
An object of the invention is to provide a wind turbine generator or a tidal current generator which is equipped with a hydraulic transmission and achieves a superior power generation efficiency, and a operation method thereof. The wind turbine generator 1 comprises a hydraulic pump 12 of a variable displacement type which is rotated by the main shaft 8, a hydraulic motor 14 of a variable displacement type which is connected to the generator 20, and a high pressure oil line 16 and a low pressure oil line 18 which are arranged between the hydraulic pump 12 and the hydraulic motor 14. The pump controller 32 obtains a target torque of the hydraulic pump 12 at which a power coefficient becomes maximum, and then sets a displacement Dp of the hydraulic pump 12 based on the target torque and the pressure in the high pressure oil line 16. The motor controller 34 sets a displacement Dm of the hydraulic pump 14 based on a discharge amount Qp of the hydraulic pump obtained from the displacement Dp of the hydraulic pump 12 so that the rotation seed of the generator 20 becomes constant.
摘要:
It is intended to provide a power generating apparatus of renewable energy type in which the synchronous generator can be connected to the gird without the frequency converting circuit and which is capable of improving efficiency during low-load operation and of avoiding missing opportunities of power generation due to failure of the generator. A power generating apparatus of renewable energy type 1 may include a rotating shaft 8 rotated by the renewable energy received via a blade 4, a hydraulic pump 12 driven by the rotating shaft 8 to generate pressurized oil, hydraulic motors 14k driven by the pressurized oil, and synchronous generators 20k connected to a grid 50 without an intervening frequency-conversion circuit and respectively coupled to the hydraulic motors 14k. The displacements of the hydraulic motors 14k are adjusted independently by a motor control unit 48. A synchronizer 120 supplies a command value of the displacement of each hydraulic motor 14k to the motor control unit 48 so that before the synchronous generators 20k are connected to the grid, a frequency and a phase of a terminal voltage of each synchronous generator 20k are synchronized with the grid 50.