Variable Speed Drive Systems for Industrial Hydraulic Efficiency

[Erkan Teskancan]

## Variable Speed Drive Systems Boosting Industrial Hydraulic Efficiency

Danfoss Power Solutions, through its Vickers by Danfoss brand, offers variable speed drive (VSD) systems that optimize energy consumption and provide precise control within the automotive data ecosystem and digital supply chain.

These systems integrate hydraulic pumps, electric motors, and frequency drives to adjust motor speed according to real-time work cycle demands. This significantly enhances energy efficiency in both discrete and process manufacturing environments.

### Technical Architecture and Energy Performance

VSD systems prevent the inefficiencies of fixed-speed systems by varying the pump's rotational speed as needed. This method eliminates energy waste during low demand or idle operation, achieving energy savings of up to 60% depending on the machine's work cycle.

The portfolio is divided into two main technical configurations based on dynamic needs:

• Induction Motor Solutions: An open-loop control system for applications ranging from 3 kW to 250 kW, utilizing a PVM Code B axial piston pump and a VLT AutomationDrive FC 302 frequency drive. It provides 20% to 40% energy savings compared to fixed-speed systems.
• Servo Motor Solutions: A closed-loop pressure and flow control system up to 100 kW, combining VGPS internal gear or PVMX axial piston pumps with an iC7-Automation drive, permanent magnet synchronous motor (PMSM) technology, and specialized p/Q control software. Energy savings range from 30% to 60%.

### Thermal Management and Acoustic Impact

These VSD units enhance system efficiency by minimizing heat generation in the hydraulic circuit. This allows for smaller oil coolers or their complete elimination, which reduces installation costs while extending the life of hydraulic seals and fluids.

Furthermore, the low-speed operation of the motor and pump reduces mechanical noise, offering more flexible placement options and potentially reducing the need for additional acoustic insulation.

### Component Sizing and System Integration

The ability to utilize the motor's full speed range allows for a reduction in pump displacement without sacrificing maximum oil flow. Smaller displacement pumps require less torque, and motors can handle short-term high torque with overload capacity, enabling the selection of smaller motor frame sizes. This reduces the physical footprint of the device and the required installed power.

### Industrial Application Areas

VSD technology provides high efficiency, especially in manufacturing environments where work cycles occasionally demand intense power. Prominent applications include:

• Precise pressure control in metal forming and presses
• Energy optimization during long cooling phases in injection and rubber molding
• Thermal stability and low noise in machine tools and casting applications
• Reliable flow control for automation lines in the food processing sector

According to Juraj Bittner, Product Manager for Industrial Solutions at Danfoss Power Solutions, the integration of Danfoss drives and Vickers pumps offers ease of commissioning and operation, and the p/Q control logic reduces design and installation times.

These advanced variable speed drive solutions are elevating energy efficiency and system performance in industrial hydraulic applications to new levels.