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Job Sheet 3 – Trainer Components

The Wind Turbine Hydraulic Pitch Hub Training System (Figure 3-1) provides the materials

necessary to learn how wind turbines capture and use wind energy. In this exercise, you will

identify and become familiar with each of the components of a wind turbine that uses hydraulic

better understanding of each item’s function and purpose.

Figure 3-1. Hydraulic Pitch Hub Trainer.

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20 © Festo Didactic Inc. 88390-20

System Parts

Rotor blade(s)—On the hydraulic pitch hub trainer, one of three blades controlled by the

software is represented by a silhouette stenciled onto a central plate (Figure 3-2). This allows

the trainer to show a working blade in a scale large enough to display the actual workings of

a full-scale wind turbine blade pitch control system. If an actual blade were present, it would

extend from the back of the trainer, as shown in Figure 3-3.

Figure 3-2. Rotor Blade.

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Figure 3-3. Depiction of Blade Secured to the Back of the Hydraulic Pitch Hub Trainer.

Slewing bearing—allows the blade to pivot relative to the hub or, in this case, the trainer

(Figure 3-4). The trainer represents a portion of a full-scale wind turbine rotor hub and the

slewing bearing is a scaled-down version of the component found in the full-scale wind turbine.

Unlike the slewing bearing found in an electrical pitch control system, the slewing bearing of a

hydraulic pitch control system has no internal teeth or meshing pinion gear.

Figure 3-4. Slewing Bearing.

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Hydraulic cylinder—a key component in the hydraulic pitch control system. The hydraulic

of the slewing bearing, the linear translations of the hydraulic cylinder are transformed into a

rotational motion used to adjust the blade pitch position. An electrical transducer integrated into

the cylinder (located on the lower end of the cylinder) transmits piston position data back to the

PLC.

Figure 3-5. Hydraulic Piston.

Hydraulic power unit

the blade angle by actuating a hydraulic cylinder (Figure 3-6).

Figure 3-6. Hydraulic Power Unit.

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Trainer Components

Hydraulic pressure gauges—provide a reading of the pressure on a scale graduated in units

monitor the pressure on the hydraulic cylinder section of the hydraulic system. The gauge on

pressure is between 600 and 900 psi.

Figure 3-7. Pressure Gauges.

Human machine interface (HMI)—touch screen that is used to operate and monitor the

hydraulic pitch hub trainer (Figure 3-8). The HMI uses a system called supervisory control and

Figure 3-8. Human Machine Interface.

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Main power switch (A)—switches the power to the hub trainer on and off (Figure 3-9A).

Start push-button switch (B)—closes the contactors that powers on the hydraulic motor after

the main power switch is set to the on (|) position (Figure 3-9B).

Emergency Stop push-button switch (C)—opens an electrical contactor on the trainer so that

all electrical energy to the hydraulic unit ceases when the button is pressed (Figure 3-9C).

A

B

C

Figure 3-9. Main Power Switch, Start Push-button Switch, and Emergency Stop Button.

Electrical panel—contains the electrical supply, distribution, and control functionality for the

hub trainer behind a clear, lockable door (Figure 3-10).

Figure 3-10. Electrical Panel.

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24 Vdc power supply—part of the electrical control panel, provides 24 volts direct current to

the hub trainer for control purposes (Figure 3-11).

Figure 3-11. 24-Volt Power Supply.

AC motor drive—used to control the speed of the hydraulic pump motor (Figure 3-12).

Figure 3-12. AC Motor Drive.

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Circuit breaker—a switch that opens (disconnects) the electrical circuit when a certain current

the cause of the overcurrent is determined and addressed, the circuit can be closed (energized)

Figure 3-13. Main Circuit Breaker.

Fuse holder—holds fuses that burn out when a certain line current is exceeded, protecting

devices on the trainer (Figure 3-14). When the cause of the overcurrent is determined and

addressed, the burned out fuse needs to be replaced.

Figure 3-14. Fuse Holder.

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Motor starter protector—circuit breaker (also called overload relay) which protects the hub

trainer motor from overcurrent (Figure 3-15). These devices have thermal and magnetic trip

mechanisms, as well as an adjustable trip set point.

Figure 3-15. Circuit Protection.

Contactor—a relay (remote-controlled switch) that provides high-current switching capabilities

in electrical circuits (Figure 3-16). This device provides on/off control of the trainer’s motor.

Figure 3-16. Contactor.

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—digital electronic module used to drive the system’s

hub hydraulic proportional control valve which controls the hydraulic cylinder.

Media convertor—optical and digital electronic transceiver module used to communicate to the

PLC remotely (Figure 3-18).

Figure 3-18. Media Convertor.

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Programmable logic controller (PLC) and clock—digital electronic controller module used to

run the system programming used in functional operation and control of the trainer. The PLC

Figure 3-19. PLC and Master Interface.

Distributed I/O system

a remote communication bus (Figure 3-20).

Figure 3-20. Distributed I/O System.

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OBJECTIVES

In this job, you will identify and review the function of the main components of the

hydraulic pitch hub trainer.

PROCEDURE

Use the information provided in the Information Job Sheet to respond to these

Which of the following is the linear translation device that is coupled

between the hub frame and slewing bearing, and transmits the force to

pitch the blade?

a. Slewing bearing

b. Hydraulic unit

c. Hydraulic cylinder

d. Proportional control valve

Which component of the hydraulic pitch hub trainer is represented in the

following graphic?

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Which component is represented in the following graphic?

Where on the hydraulic pitch hub trainer is the following component

located? (If necessary, look for it on the trainer.)

Which component is used to remotely communicate with the hub

trainer?

Which component provides on/off control of the trainer’s motor?

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Trainer Components

Name: _________________________________ Date: _____________________

Instructor approval: ___________________________________________________

Which easily accessible component opens an electrical circuit of the

trainer so that all electrical energy to the hydraulic unit ceases?

Which device protects the hub trainer motors from overcurrent?

Which component helps to determine the cylinder position?

Which electrical component supports optical connectivity?