Servo-Hydraulic System Energy Savings Analysis

The HWAMDA SPV5 servo-hydraulic system pairs a permanent magnet synchronous servo motor with a fixed-displacement axial piston pump. Unlike conventional hydraulic systems where a constant-speed motor drives a variable-displacement pump (which still consumes 30-40 percent of rated power at zero flow), the SPV5 servo motor speed varies from 0 to 1800 RPM proportional to the actual flow demand. During injection at 368-422 mm/s, the motor runs at peak speed delivering maximum flow and pressure. During the cooling phase (which occupies 60-70 percent of a 4.0s cycle), the motor idles at near-zero RPM, consuming less than 0.5 kW. The accumulator system in the SPV5 stores hydraulic energy during low-demand phases and releases it during peak-demand injection, enabling injection speeds that would otherwise require a motor 40-60 percent larger. This architecture delivers peak injection power of 75-180 kW (depending on tonnage) while the installed motor is sized at only 30-75 kW. The power factor exceeds 0.95 across the operating range, compared to 0.7-0.85 for conventional induction motor systems, further reducing apparent power demand and utility costs.

The HWAMDA SPV5 INOVA controller provides real-time energy monitoring that enables ongoing optimization beyond the baseline servo-hydraulic savings. The controller displays instantaneous power draw (kW), cumulative energy per cycle (kJ), and specific energy consumption (kWh/kg) on the main dashboard. These metrics update every cycle, allowing operators to see the immediate impact of parameter changes on energy consumption. Reducing pack pressure from 90 to 75 MPa (where quality allows) typically saves 3-5 percent energy. Shortening cooling time by 0.2s saves energy both directly (less hydraulic holding power) and indirectly (higher throughput per kWh of fixed overhead power). The INOVA controller logs energy data per hour, shift, and day, enabling management reporting on energy KPIs. Integration with factory MES (Manufacturing Execution System) via OPC-UA allows centralized energy monitoring across multiple SPV5 machines. Monthly energy trend analysis identifies degradation: a progressive increase of 5-10 percent in specific energy consumption over 3-6 months typically indicates hydraulic system issues (pump wear, valve leakage, or oil degradation) requiring maintenance.

Quantifying the return on investment for upgrading from a conventional hydraulic machine to an HWAMDA SPV5 servo-hydraulic requires accounting for energy savings, productivity gains, and maintenance cost reduction. Energy savings: for a 380-ton machine running 24/7, the annual energy saving versus conventional hydraulic is USD 10,500-20,000 depending on local electricity rates. Productivity gain: the SPV5 parallel movement capability (charging on fly during mold opening) reduces cycle time by 0.3-0.5s versus sequential-operation machines, increasing annual output by 8-12 percent. On an 8-cavity yogurt cup line producing 7,200 cups/hour, a 10 percent increase adds 6.3 million cups per year at a conversion margin of USD 0.003-0.005 per cup = USD 19,000-31,500 additional margin. Maintenance cost: servo-hydraulic systems require oil changes every 4,000-6,000 hours (versus 2,000-3,000 for conventional), and the sealed system reduces oil consumption by 60-70 percent. Annual maintenance savings: USD 2,000-4,000. Total annual benefit: USD 31,500-55,500. Against a machine investment of USD 85,000-120,000 for the HMD 380M8-SPV, simple payback is 1.5-3.8 years.

Proper electrical infrastructure maximizes the energy efficiency benefits of HWAMDA SPV5 servo-hydraulic machines. The servo motor's variable frequency operation generates harmonic currents (5th and 7th harmonics primarily) that can affect power quality if multiple machines share an electrical supply without filtering. For installations of 4 or more SPV5 machines, install an active harmonic filter or ensure the supply transformer is de-rated to 80 percent of nameplate capacity. Power supply specifications for SPV5 machines: 380V/415V 3-phase, 50/60 Hz, with voltage regulation within plus or minus 5 percent. The HMD 380M8-SPV draws a peak current of approximately 120A during injection, dropping to 15-25A during cooling. The average power factor of 0.95 means minimal reactive power compensation is needed. Install a power meter (Carlo Gavazzi EM340 or equivalent) at each machine disconnect to enable individual machine energy tracking. Compressed air requirements for valve gate actuation and air-assist ejection total 200-400 NL/min at 6 bar per machine. Cooling water supply at 15-25 degrees C and 3-5 bar pressure, flow rate 60-100 L/min per machine. Proper utility sizing prevents voltage sags during injection that can affect servo motor response and injection speed consistency.