Danfoss Power Solutions’ Editron division—the company’s hybrid and electric powertrain systems division—recently worked together with construction equipment manufacturer Doosan to electrify two excavator models. The 16-ton wheeled excavator and 30-ton crawler excavator are powered by electric drivetrains provided by Danfoss Editron instead of diesel engines.
In addition to the electric powertrain, Danfoss also provided a control system and display utilizing its PLUS+1 software to help ensure an optimized solution.
For the project, Electric Construction Equipment (ECE)—which has a license agreement with Doosan to modify its machines for European dealers—worked with Electrauvision, a division of Danfoss’ partner Hydrauvision, which provides system integration for various applications. Electrauvision supplied ECE with the electric drivetrains and worked together with the company to ensure optimized installation of the Danfoss components.
Integration Key to Successful Engine Swap
To convert the Doosan excavators to electric power, their engines were swapped out for the Danfoss electric powertrain consisting of an electric motor and inverter. The machines’ hydraulics were left untouched, says Antti Väyrynen, director of Off-Highway for Danfoss’ Editron division.
He says the general requirements of the excavators were easy to meet with the Danfoss Editron technology. The biggest challenge when replacing a combustion engine is the need for the electric powertrain to interface with auxiliary systems. “The most challenging part was the HMI (human machine interface) and the DC controller connection because we have to keep the functional safety and the vehicle homologation as it was before,” he explains. Doing so ensures the machine will operate as it was originally intended.According to Väyrynen, the Danfoss Editron system is one of the most efficient in the market. This is important for ensuring the battery holds its charge which leads to maximum operation time before recharging. The components are designed for use in heavy-duty operations and harsh environments which further aids performance optimization for customers as there is less chance of wear-and-tear due to the operating conditions. “[The components] have been designed for off-highway machines; this maximizes uptime, lifetime and most importantly the total cost of ownership,” says Väyrynen.
Included in both excavators is an exchange battery swapping system comprised of an electric powerbox which provides power to the electric drivetrain. Väyrynen explains the system works by having the battery provide energy to the electricity consumer and the motor inverter uses that energy to drive the electric motor. The motor is connected to the main hydraulic pumps; hydraulic oil flow and power demand set the working speed of the electric motor. Danfoss’ customized PLUS+1 control system enables communication between these components.
Use of the PLUS+1 hardware and tool chain aided integration of the electric systems. Ensuring optimized integration was important says Väyrynen because the companies were converting an existing excavator platform to electric power. “This PLUS+1 system is handling the power management in the electric system,” he says. “It controls the main Editron inverters as well as the auxiliary systems [such as] cooling, the 24V power supply and the HMI.”
The collaboration with Doosan is one of several electrification projects in which Danfoss has participated over the past several years. “We have electrified almost [every type of] mobile work machines you can think of,” says Väyrynen.
Because of its experience electrifying various types of equipment, Danfoss Editron has gained a wealth of knowledge in how to develop the necessary technology as well as meet the requirements of OEMs and their end-use customers. The company’s technology has also amassed several operating hours in the field, proving its capabilities and reliability. This expertise will be beneficial as electrification advances in many industries and Danfoss Editron continues to work with various OEMs and machine types.