IFP is continuously providing its customers with new technology to meet rigorous application requirements while improving overall system efficiency and control.


A hydraulic power unit (HPU) is a common product that IFP supplies to its customers for all types
of hydraulic applications.  Most customers order their HPUs with standard electric motors and across-the-line motor starters.  These electric motors spin at a constant RPM.  Because the electric motor spins at a constant RPM, the hydraulic pump coupled to the motor is constantly flowing oil and is likely wasting energy in between system operations.

Variable frequency drives (VFD) available that can change the speed at which electric motors spin.  The hydraulic pump is driven at the appropriate RPM to maintain the system requirements, thus saving energy and creating a drive controlled pump.  A VFD controlled system can close the loop around different flow requirements per the specific operation.  This type of system can also close the loop around pressure and duplicate a variable displacement pressure compensated pump with a fixed displacement pump with a preset flow limit.  Controlling flow and pressure by these means is an efficient alternative compared to using valves in a sometimes complex circuit.


By allowing the VFD controlled HPU to match the system pressure and flow requirements by varying the pump speed, there are several other advantages to using these VFD controlled HPU systems.  By reducing energy put into the system, less heat is generated that has to be dissipated by the system.  There are typically noise reductions with VFD controlled HPUs.  With reduced heat and reduced system shock, this typically leads to longer component life depending on the load cycle.  Hi-lo systems can now be completed with just one fixed displacement hydraulic pump.  By over-speeding the pump for extra volumes of fluid, the VFD controlled system does not need a low pressure/high flow pump along with the high pressure/low flow pump.  Charging an accumulator can become more efficient as well.  Once the accumulator is charged, the VFD controlled HPU can slow down the flow output of the hydraulic pump and maintain the system.  Unloading the pump for accumulator charging is typically done with extra valves and consuming unnecessary energy.  Overall costs of hydraulic systems can be reduced because smaller hydraulic pumps can be used, less valves are required, less or no cooling for heat dissipation, and smaller reservoirs can be used.

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Benefits of VFD Controlled HPUs

The applications are endless for VFD controlled HPU systems.  These systems can be used on anything from a simple filter and lubrication system to extremely complex test stands and presses.  With increased efficiency and control, VFD controlled HPU systems will become more common in industry.

For more information on how you can utilize Drives and VFD controlled HPUs, please contact us here to receive a personalized contact by an IFP Application Engineer:

About IFP Automation

IFP Automation supplies innovative technology and design solutions to the automation and mobile marketplaces.  Our firm is a technology supplier specializing in the design and supply of automation and motion control products to OEM, integrator, and end user customers. Companies partner with IFP because they like the depth of our product and application knowledge and our commitment to outstanding customer service.

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