Pitch control is important in utility-scale wind turbines. Pitch affects how much energy the wind turbine can collect. When wind speeds increase, pitch can be adjusted to minimize the turbine's response to high winds.

Various pitch systems are used in wind turbines today, including hydraulic and electrical. The pitch system utilized by your wind turbines affects performance and required maintenance. Every wind turbine technician needs to be familiar with hydraulic and electric pitch systems, as both are used in modern turbines.

This article will provide a brief overview of hydraulic versus electric pitch control in wind turbines, so you can understand the differences when moving forward with a future as a wind turbine technician.

Overview of Pitch Control Technologies

Understanding the basic difference between these core wind turbine pitch system approaches illustrates the relevant maintenance considerations required for both implementations of pitch control.

Hydraulic Pitch System Basics

Hydraulic pitch systems use pressurized fluid to create the movement (change in attack angle) of wind turbine blades. Many older turbines have this type of system as hydraulic systems predate electrical systems.

Even today, hydraulic pitch systems are often preferred for larger turbines with heavy blades and hubs due to the benefits of compressed fluids when dealing with larger or heavier weights. Wind turbine technicians performing work on hydraulic pitch systems must inspect for residue, deteriorated seals, leaks, and more.

Hydraulic Pitch Maintenance

Wherever there is fluid under pressure, there is a chance of leaks. Much of the work of maintaining hydraulic wind turbines involves checking for leaks, maintaining high pressure, and assessing the condition of the hydraulic fluid. Drips, wet hoses, and falling pressure are the kinds of problems that you can expect to address as a wind turbine technician working on a hydraulic system.

Electric Pitch Systems Basics

Electric pitch systems have electrical components rather than compressed fluid systems. Many newer and smaller turbines utilize these systems. The main components technicians must inspect and service in electric pitch systems include the batteries, motors, and gears within the turbine.

Electric Pitch Maintenance

Electric wind turbines require technicians to inspect components, including motors and wiring. Technicians must monitor electrical components and perform replacements and repairs as necessary to ensure the wind turbine continues to operate. These turbines are easier to maintain than hydraulic turbines because the components are fully enclosed and often continue to operate until their parts wear out.

Day-to-Day Maintenance: What Techs Actually Do

If you're considering studying to become a wind turbine technician, it's important to know what technicians actually do. As we have already seen, the technician's role varies depending on the type of system being serviced.  Here are some of the most common maintenance issues addressed by wind turbine technicians while troubleshooting pitch systems today:

Common Hydraulic Failures 

Leaks and pressure loss are the most common problems with hydraulic pitch systems. Sometimes these problems include contaminated fluid and worn components. In Canada, hydraulic pitch systems are also vulnerable to cold-weather issues that can cause the turbine to run slowly and sluggishly.

Common Electric Failures 

Electrical pitch systems typically experience failures of motors, relays and current-control components. In the colder seasons, the battery technology in these systems is also more likely to fail in extreme cold.

General Safety and Emergency Situations

Failures of the pitch system can cause downtime for the wind turbine. Some studies indicate that nearly 25% of wind turbine downtime is attributable to pitch system related issues. Maintaining the pitch system can prevent failures that endanger the system or lead to damage.

Pitch System Response Time

Severe storms can arise quickly. A quick pitch response can help protect the turbine and its internal components. Hydraulic and electric systems react differently during severe weather. Hydraulic systems are more robust and able to handle storms, even for large turbines. Electrical systems are most commonly found on smaller turbines that are less vulnerable to wind damage.

Reliability and Long-Term Wear

As turbines age, they need more maintenance, more frequent inspections, and more upkeep. Since hydraulic system failures can be difficult to clean up, it's important to catch problems in their early stages.

Electric systems are easier to maintain and may sustain less damage during maintenance, but it's still important to catch these issues as early as possible to prevent extended downtime.

What This Means for Wind Technicians

Employers want wind turbine techs who understand both hydraulic and electric systems. Knowing how the pitch systems affect troubleshooting and safety can impact your career growth. This is why it's important to learn about wind turbines from a technician training program that's trusted by experts. Getting thorough training on both system types can make you more competitive in the job market.

Wind Turbine Technician Training

In a wind technician program, students learn how to identify problems and maintain hydraulic and electric pitch systems. Since a large percentage of wind turbine downtime is a direct result of the pitch system, this is a core skill for wind technicians to have.

Having a strong foundation in wind turbine technology can help you start a career that will take you far. To learn about wind turbine pitch systems and more, explore the Wind Turbine Technician training program at George Brown Polytechnic. Call us at 1-888-553-5333 or email at [email protected] to speak to one of our Program Consultants.