Aluminum Extrusion Press Servo Retrofit Project Case

A large aluminum extrusion manufacturer needed to upgrade their 1400T and 1250T aluminum extrusion presses to reduce energy consumption and improve production stability.

The original system used three-phase asynchronous motors with hydraulic pumps, which operated at constant speed regardless of load conditions.

This caused significant energy losses during non-extrusion stages.

• High electricity consumption

• Energy loss from hydraulic overflow

• Motors running at constant speed

• Low efficiency during idle stages

• High operating temperature

Energy loss in traditional hydraulic systems can reach 25%–35% of motor output power.

Each extrusion press was equipped with:

AC Power
   │
Star-Delta Starter
   │
Asynchronous Motor
   │
Hydraulic Pump
   │
Extrusion Press

Because the motor speed was fixed, the hydraulic system relied on overflow valves to regulate pressure, which resulted in large energy losses.

To improve system efficiency, the original motors and control cabinets were replaced with servo-driven hydraulic systems.

AC Power
   │
Servo Drive
   │
Oil-cooled Servo Motor
   │
Hydraulic Pump
   │
Extrusion Press

The servo motor adjusts speed based on the real-time hydraulic demand of the extrusion machine.

This allows the system to deliver only the required power, eliminating unnecessary energy consumption.

The servo system provides on-demand power control.

Traditional system:

Constant motor speed
→ constant oil pump flow
→ pressure regulated by overflow valve
→ energy converted into heat

Servo system:

Load demand detected
→ servo drive adjusts motor speed
→ hydraulic flow matches actual demand
→ minimal energy loss

This control strategy significantly improves the efficiency of the hydraulic system.

Typical extrusion press cycle:

High power is only required during the extrusion stage, but traditional motors run at full speed during the entire cycle.

Servo control eliminates this inefficiency.

Annual electricity saving:

22 kW × 24 h × 319 days
= 168,432 kWh

Annual electricity cost saving:

≈ 128,000 RMB

Annual electricity saving:

160,776 kWh

Annual electricity cost saving:

≈ 122,000 RMB

Besides energy savings, the servo upgrade also improves production performance.

Production output increased by approximately 2%.

Servo systems provide:

• precise speed control

• stable extrusion pressure

• smooth deceleration at the end of extrusion

This improves product quality and consistency.

Benefits include:

• reduced hydraulic shock

• lower oil temperature

• longer equipment lifetime

• reduced maintenance costs

The system includes complete protection functions such as:

• overload protection

• overcurrent protection

• overtemperature protection

• short circuit protection

• alarm and interlock system

All electrical design complies with IEC standards.

The servo retrofit project successfully upgraded traditional hydraulic extrusion presses to a high-efficiency servo control system.

• Energy saving: about 20%

• Annual electricity saving: up to 168,000 kWh

• Production increase: about 2%

• Investment payback: around 17–18 months