Wind turbine with the ChapDrive drive train solution

ChapDrive has developed a new drive train solution for wind turbines. The core technology is a hydraulic transmission with a variable speed control system. The technology is characterized by relocating the majority of the critical components from the nacelle in the top of the turbine down to a power unit at the foundation. This reduces the top weight significantly and simplifies service access. In addition the need for a mechanical gearbox and frequency converters used in traditional wind turbine technology is eliminated. Power is generated by a synchronous generator that will comply with grid regulations being required for wind turbines in the future. A wind turbine equipped with a hydraulic transmission is illustrated in Figure 1.

FIGURE 1: Illustration of a Wind turbine with the ChapDrive drive train solution

ChapDrive hydraulic transmission with variable speed control

A principle diagram of the hydraulic transmission is illustrated in Figure 2. The mechanical gearbox is replaced by a low speed hydraulic pump connected to a high speed hydraulic motor with a closed loop hydraulic circuit. The hydraulic motor is connected to the generator operating at synchronous speed. The hydraulic motor has variable displacement volume, and by altering this displacement, the exchange ratio of the rotor speed to the generator speed can be changed and thus the system operates with a variable gear ratio in order to optimize the energy capture. The flow is controlled by the ChapDrive variable speed control securing stability and efficiency of the system.

FIGURE 2