Revolutionizing Hydraulic Power Units with Variable Frequency Drives
“When used correctly, VFDs can make a giant leap forward in your hydraulic system’s operation — focusing on efficiency, precision, and durability.”
Hydraulic power units are the backbone of heavy equipment functionality, providing the essential force and precise control required for demanding industrial applications. For heavy equipment OEMs, an HPU solution that is tailor-made to fit specific machine requirements can optimize energy efficiency, enhance reliability, and extend equipment lifespan by ensuring every component—from pumps to controls—is matched perfectly to the task at hand. And while it’s easy to settle for existing hydraulic solutions, hydraulic innovation, including the use of variable frequency drives (VFDs), can lead to not only improved performance, but also energy efficiency and a quieter machine.
At GS Global Resources, innovation in hydraulic power units is driven by decades of expertise combined with cutting-edge technology. In the video above, one of our Account Managers Pat Brady, shares insights into how VFDs have transformed hydraulic power applications for OEMs.
“With VFDs driving the electric motor that powers the pumps, we can achieve a speed range from 200 rpm all the way up to 3000 rpm,” Brady explains.
This flexibility allows GSGR to tailor solutions that use smaller pumps with less torque while still delivering high peak speeds. The result is a proportional solution that outperforms simpler valves by improving system performance, cutting energy usage, and providing more precise control. Energy efficiency and operational reliability are at the forefront of these advancements. Since 2016 energy efficiency laws went into effect, motor inrush current can be 10 to 15 times the nameplate rating, but with a VFD, it can be kept to under two times that nameplate value. This soft starting feature reduces electrical strain on the power grid and prevents excessive power draw from generators.
Another major advantage is reducing mechanical shock in hydraulic systems, enhancing longevity and smooth operation. Using VFDs, the pump speed can ramp down as a cylinder approaches the end of its stroke, eliminating these damaging pressure transients.
“If a hydraulic cylinder runs out of stroke at full speed, the pressure can spike to 8 or 10 thousand psi — that’s four times running pressure, which causes shock,” Brady says.
GS Global Resources’ application of VFDs follows a pragmatic approach that honors simplicity while delivering sophisticated control. Brady explains that you can teach the machine to slow down near the end of a stroke, just like an operator would manually back off a valve. This method allows pumps to precisely position components with repeatability within thousandths of an inch, improving product quality and machine lifespan.
“We’ve been applying Danfoss drives since before I got here in 1991, with more than 40 years of experience using VFDs on various loads,” Brady says. “Our expertise allows us to rapidly customize VFD hydraulic solutions optimized for specific needs.”
Moreover, VFDs help address practical challenges like maintaining pump lubrication at low speeds and ensuring continuous operation without sudden stops — critical for maintaining process stability.
Contact us to find out how we can take the framework of a successful HPU solution like what was outlined here, and customize that for your machine and application.
