How VFD Technology on Hydraulic Power Units Helps Improve Performance | Case Study

How AC Variable Frequency Drives on Hydraulic Power Units Will Help Improve PerforamnceCombining electronic and hydraulic technologies can add efficiency and functionality to machinery and processes that use hydraulic pressure to operate. The hydraulic power unit (HPU), a workhorse of the industry, can demonstrate optimized performance through the use of variable frequency drive (VFD) technology. The combination of these two technologies creates what is referred to as a DCP--Drive Controlled Pump.

Popular HPU applications

  • Metal forming presses

  • Stamping Presses

  • Die casting machines

  • Rubber forming presses

  • Accumulator charging

  • Wood presses

  • Roll winders


In many industrial processes involving an HPU, an unregulated motor running at maximum speed is probably wasting energy. Optimizing the motor speed to produce only the pressure and flow required, and reducing the motor speed during low flow demand or parts of the cycle requiring pressure to be held can achieve significant energy savings.

By using variable speed drive technology, instant savings can be realized. By automatically adapting the pump’s speed to match changes in demand, variable speed drives are the perfect addition to many hydraulic systems.

Testing results

An example of energy saving tests run by Parker on a hydraulic press system clearly shows that substantial savings on energy are possible using a variable speed drive to reduce motor speed during parts of the machine cycle with low flow demand. Plus, by over-speeding a pump at times of low-pressure demand, a second pump could be eliminated.

The results, in this case, were highly desirable in any manufacturing environment:

  • An average power need of just 34 HP (25kW) compared to 50 HP (38kW) using an unregulated pump, over the entire press cycle,

  • Improved efficiency equates to less heat generated, and

  • Less audible noise produced.

Packaged solutions

Few competing companies can claim the expertise in both hydraulics and electronic drives that Parker brings to the table. With many sizes and styles of pumps and HPUs, and VFDs ranging from fractional to 2000 HP, few applications are out of Parker's range. To save time and expense, multiple pre-configured VFD programs are available, covering applications like P (system pressure) control, Q (pump flow) control, and Hi/Lo control.

Find out more about Parker's experience and capabilities in variable frequency control for hydraulics by registering for our on-demand webinar. 

Other articles on AC drives:

New Winding Technology for Paper Converting Delivers Energy Savings

Ten Dos and Don'ts of Applying Variable Speed Drives to Hydraulic Pumps 

VFD Provides Energy Saving on Hydraulic Power Unit

VFD Slashes Wastewater Treatment Plant’s Energy Costs

VFD Cuts Costs on Factory Air Compressor

VFD Eliminates Bottleneck in Canning Plant

Have a question about Parker products or services? We can help: Contact Us!

Comments for How VFD Technology on Hydraulic Power Units Helps Improve Performance | Case Study

Very well written article. Insightfull.
In the field of technology new discoveries and continuous research is the main aspect. It helps to improve the workings as well as performance of the regarding machinery. Thanks a lot for telling us about how variable frequency drives have played their important part in improving the performance.

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