Fig 1.
Relative displacement of the toothed components within a PG system.
This image illustrates the meshing of gears within the transmission chain system. (a) shows the meshing and rotation of the sun-gear and planetary gears in the planetary gear train. (b) shows the meshing and rotation of the planetary gears and the inner gear ring in the planetary gear train.
Fig 2.
Coupling model of the machine –electricity –control -grid of a WT drivetrain.
The diagram presents a schematic of the coupled wind turbine drivetrain system, encompassing the aerodynamic, mechanical, electrical, control, and grid components. From front to back, it illustrates the aerodynamic load model, mechanical transmission system model, generator model, generator converter control, DC decoupling stage, grid-side converter control, and grid model, respectively.
Fig 3.
Design of the drivetrain test bench and physical test bench.
(1 – Drive motor; 2 -Reducer; 3, 5 – Coupling 1; 4, 10 – Speed and torque sensor; 14 – Generator; 9, 11, 13 -Coupling 2; 12 – Magnetic powder brake; 6, 7, 8 – Gear speed reducer).
Fig 4.
PI control of machine-side converters.
Fig 5.
Structural diagram of the exponential SMC with variable coefficients.
Fig 6.
PI control block diagram of the harmonic current.
Fig 7.
Harmonic control strategy based on the SMC controller.
The diagram illustrates an SMC-PR controller, which primarily consists of a speed loop and a current loop. The speed loop is regulated using the SMC method, whereas the current loop is managed using the PR control method.
Table 1.
Parameters of different control strategies.
Fig 8.
Dynamic behavior of generator rotor speed in response to various control strategies.
The figure shows the time-domain and frequency-domain responses of the generator rotor speed under four different control modes.
Table 2.
Reaching steady-state time and maximum overshoot.
Fig 9.
Lateral VD of the first-stage planetary output gear.
The figure illustrates the lateral vibration displacement of the first-stage sun gear under four different control strategies employed by the generator.
Fig 10.
Lateral VD of the second-stage planetary output gear.
The figure illustrates the lateral vibration displacement of the second-stage sun gear when the generator adopts four different control strategies.
Fig 11.
Lateral VD of the PS high-speed gear.
The figure shows the lateral vibration displacement of the parallel high-speed wheel gear when the generator employs four different control strategies.
Table 3.
Vibration amplitudes of the primary components (um).
Fig 12.
Vibration amplitudes of the primary components within the transmission system.
Fig 13.
Dynamic responses of the generator current under different control strategies.
Fig 14.
Dynamic responses of the generator ET under different control strategies.