Renewable energy is rapidly becoming the dominant form of power generation. And wind power lies at the forefront. Worldwide wind capacity reached more than 600 gigawatts at the end of 2018. Some countries are now generating more power from wind than from other energy sources. With an annual growth rate of around 10%, there is an insatiable demand for the many components that comprise modern wind turbines.
Special plant manufacturer Hedrich Group, for example, supplies rotor blades for wind turbines. These blades (typically three per turbine) are attached to a hub that sits atop a tower to capture the energy inherent in the wind. Hedrich Group realized that its vast manufacturing and casting experience could be harnessed to the benefit of the wind sector. The company used its knowledge to develop a process to vacuum cast the rotor blades that are needed to produce wind energy. This approach provides an accurate and complete cast for the first time, significantly improving product quality.
Conventional casting suffers due to the presence of air and gas during the process. This reduces casting accuracy and reduces overall quality. Hedrich Group devised a fully automatic vacuum infusion process for the casting of rotor blades that completely eliminates air and gas from the casting module.
“This increases the structural strength of the end product and eliminates costly finishing work to remove remaining cavities,” says Peter Rektorschek, Head of Digital Solutions at Hedrich Group.
Siemens Brings Automation
The Hedrich Group relies on control and automation technology from Siemens for improved product quality, reduced material wastage, lower maintenance, and accelerated processes. Here is how it works:
Resin and hardener is conditioned, degassed, and dehumidified under a vacuum in an automated mixing plant with the SIMATIC ET 200SP acting as the head controller. Conditioned material is pumped into a ring line up to 500 meters long, which contains up to eight modular infusion stations for several rotor blade half shells. Known as Infucubes, each half shell infusion is automated by a SIMATIC S7-1200, which connects to the head controller and communicates via TCP/IP.
Valves with sensors monitor how the material is drawn into the half-shells. A scale is used to ensure the exact weight is achieved. The sensors and the scale are connected to the controller. The controller stops the process as soon as the mold can no longer accept any more material. Once the half-shell of a rotor blade is filled, it takes about 24 hours to harden, after which it can be shaped or bonded to a second half-shell.
“Thanks to SIMATIC S7-1200 with CPU 1214C, each Infucube operates independently,” says Rektorschek.
He adds that this means more accurate monitoring of processes, greater precision in project engineering, and centralized management of Infucubes. Due to adjustments to plant floor and system design, the customer can now add more Infucubes to their system or replace defective stations during the process. This has materially reduced downtime and has heightened overall availability. The combination of the central controller from Siemens and the SIMATIC KTP400 Basic Panel on the new Infucube, operators can access all relevant status information and process data. They can also monitor material transfer towards the end of the process in order to reduce waste.
Why Choose Siemens?
Why did Hedrich Group select Siemens? Before it entered the wind power sector, the company was already an established leader in vacuum plant manufacturing for electrical applications. Hedrich has been a long-term user of the SIMATIC S7-1500 for larger plants in all areas of the company.
Overall, about 70% of controllers throughout the company come from Siemens, along with almost all its control cabinet equipment. Rektorschek notes that Siemens support and price-performance were better than alternatives. The easy accessibility of the controllers via remote maintenance was also an important consideration, as was being able to connect the plants to the Siemens MindSphere cloud-based Internet of Things (IoT) operating system. Thus, the SIMATIC S7-1200 was an obvious choice to control the Infucubes.
“Both controller families can be programmed using Totally Integrated Automation (TIA) Portal engineering platform, and almost every program module can be swapped between the controllers as required,” says Rektorschek. “This has allowed me to create standards that we can reuse on both controller platforms. If you also include the onboard peripherals, SIMATIC S7-1200 is even more cost-effective than a decentralized ‘dumb’ solution.”
The company is now working on how to harness the SIMATIC S7-1200 in more of its operations. For example, there is a plan to include the controller in standard modules such as the vacuum pump set in all Hedrich plants.
“Thanks to SIMATIC S7-1200, project engineering time can be shortened by up to 70%,” says Rektorschek.Have an Inquiry for Siemens about this article? Click Here >>