Electric Motor Applications in Electric Excavators: High-Performance Solutions for Construction Machinery

With carbon neutrality and reduced reliance on fossil fuels as a global goal, electric excavators are a better option than traditional diesel. Electric excavators are made with an electric motor, which is the main component in terms of suitability, efficiency, reliability, and overall performance. Two main electric motors are used for electric excavators: Permanent Magnet Synchronous Motors (PMSM) and AC Induction Motors (ACIM).

1. What are the main motor needs for electric excavators?

Electric excavators work in a demanding environment and require motors that have the following factors:

High torque and overload: Excavators have heavy-duty digging and lifting requirements. Electric motors used in excursion excavators must produce typical torque at low speeds with reliable overload.

Speed range and efficiency: Electric motors should be efficient over a wide range of speeds to accommodate both high-speed travel and low-speed use with a load.

Compact and sealed: Electric motors should be compact, candleproof, waterproof, and optimized for thermal management to support site conditions.

Precision and quiet: Motors used in excavators must be able to respond to operator inputs quickly and quietly for comfort and productivity.

2. Benefits of Permanent Magnet Synchronous Motors (PMSM)

PMSMs are being used in medium to large electric excavators, due to their benefits of:

Energy efficiency: PMSMs have low rotor losses, which result in efficiencies greater than 90%. Many excavators, particularly electric machines, operate in a start-stop fashion, meaning that energy efficiency will be extremely beneficial.

High torque and speed accuracy: Most PMSMs will allow for smooth, predictable movement and precise control with sophisticated vector or direct torque control algorithms.

Compact size and lower thermal generation: PMSMs naturally have a smaller footprint and low-thermal generation; therefore, they can be advantageous when design space and heat dissipation are limited.

3. Benefits of AC Induction Motors (ACIM)

While ACIMs do have slighter lower speeds than PMSMs, there are excellent benefits of ACIMs that result in their use in some products:

Proven reliability and low cost: The upside of a simple structure and lower production cost makes them useful in situations where cost is paramount.

Good starting torque: Because of their design and flexibility with more inexpensive vector frequency drives, ACIMs can have acceptable low speed performance and lower torque outputs.

High versatility: ACIMs are fantastic motors for continuous heavy-duty labor in any environment.

4. Deployment Strategies of Motor Options in Excavators

Electric excavators will often provide a combination of motor types to achieve performance balance in production and final product costs:

PMSM for primary drive systems: Use for Propulsion, and main hydraulic pumps and rotary systems where performance is a priority.

ACIM where auxiliary devices are utilized: Use for fan motors, cooling systems or pumps where reliability and a lower cost are a priority.

5. Future Patterns

As battery technology and battery management systems continue to develop, these technologies will become more integral to T construction. Traditionally excavators have utilized many DSM design strategies, and the trend will continue to evolve with better design, integration, and intelligent systems. Motor design will also move towards modular motors, integrated motors, and smart motors. The relationship or synergy between intelligent control systems and motors will be a fundamental aspect, and one of the main areas of differentiation between manufacturers.