We used Editron hardware exclusively to build the wheel loaders’ electric system. Editron motors and inverters drive both the propel and work functions, while DC-DC converters and LCL filters are used for power management. The separation of the propel and hydraulic work functions also creates a significant impact on the dimensioning of the subsystems.
The propel function in our wheel loader consists of a single EM-PMI375-T800 motor with two EC-C1200-450 inverters driving it. The motor connects to a two-speed gearbox, which has a transfer case used to direct torque to either the front or rear axle. The wheel loader’s hydraulic work function uses our EM-PMI240-T180 motor and EC-C1200 inverter to drive a Danfoss Series 45 hydraulic pump. By decoupling the work function from the propel system, the input speed to the pump is independent from the propel and can be controlled variably to reduce power consumption and optimize efficiency. The electric motor can adjust and reach speed quicker than a diesel engine, increasing the response of the loader’s boom and making it easier for the user to operate.
The overall power distribution of the system is managed by a few different power electronic components from within the Editron portfolio. These components are needed to direct power to and from the two different batteries on board, as well as grid connection used for charging. The wheel loader has a main energy storage consisting of an 800V battery, as well as a 24V battery for auxiliary functions. Our EC-IDC24 DC-DC converter is used to adjust voltage levels between the 24V battery and the rest of the system, and the EC-C1200-450 converter with our EC-LCL1200 filter connects to the grid to manage the charging of the main battery. These power electronic components allow a complete electric system to be built from within the Editron portfolio.
In addition, the displays, joysticks, pedals and controllers for software all come from within the DPS portfolio. By combining this hardware with the software developed and managed by our PLUS+1® tools, Danfoss is showcasing the portfolio width and internal knowledge our teams have to support the next generation of electrified solutions in off-highway.
Software overview
With the latest advancements in electronic controls both in hardware and software, today’s machines in the off-highway market have become increasingly more complicated and advanced. Developing and controlling these machines today requires extensive software development and tools to support the vehicle throughout its lifetime. We have invested heavily in building our PLUS+1® platform to support the software needs of customers, developers, testers and engineers use to design solutions for controlling mobile machines.
Within PLUS+1®, developers have access to a variety of pre-developed function blocks and libraries, as well as compliance blocks (device drivers) for our hardware and a growing set of third-party components. The most recent addition to our portfolio is our Editron Motor Control (MCU) Block, which works with the EC-C1200-450 to drive our motors. Our engineering teams were able to leverage this block when writing the software to control the vehicle. When developing and implementing software onto our POC wheel loader, the team was able to build from existing blocks and libraries related to hydrostatic systems.
Users can benefit in several ways from our PLUS+1® environment. It provides users with a complete ecosystem, allowing them to design from scratch or import existing code if they want. No matter the tools being used to write code and control hardware in their current hydraulic applications, the OEMs are still challenged with learning about all things electric: inverters, batteries, charging systems, etc. By developing this POC solution in PLUS+1®, it allows us to create this incredible solution, all while developing new software that ultimately will get pushed out to our customers for them to use and save time on development. This will further enhance not only our tools and internal capabilities, but also the software and tools our customers need.
Performance and improvements
The transition to battery electric provides many opportunities for improved performance. Once the technology, charging infrastructure and knowledge of these electric vehicles surpasses a certain threshold, the solutions that leverage all the benefits of electrification into their design will outperform their diesel counterparts and become standard in the market.
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