| 摘要 |
A hydraulic transmission system 1 for wind or water turbine installations comprises a hydraulic pump 4a connected via a transmission line S, 6 to a plural fixed displacement hydraulic motors 4b arranged such that they can be coupled to and drive a common load 2. The motors 4b can each be selectively coupled in and out of operation to drive the load 2 and effectively achieve differing gear ratios to optimize turbine tip speed ratios based on a controller assessment of turbine fluid speed changes, generator power and transmission system pressure. Accumulators 9, 10, safety valves or actively controlled valves may be provided to reduce torque variations and ensure hydraulic pressure lies in a range about a reference value based on detection of hydraulic pressure. In an offshore system the natural frequency of the hydraulic system may be arranged to lie outside the frequency range of the waves in a desired installation site. |
