E-Mobility Engineering | November/December 2023 53 Suncar ZE150W excavator | Digest components, it is a must for us to use items that have been developed for mobile and/or off-highway applications. We have used some of these components for years, so we know about their weaknesses and can counteract them in the vehicle’s construction.” Key electrical components The inventory of electrical componentry that has to be integrated to electrify an excavator is a long one. In addition to the batteries, inverters and motors it includes a DC-DC converter, an LV distribution unit (LVDU), an integrated thermal management unit, an HV distribution unit, an AC box, an onboard charger, a charging plug and a DC fastcharging interface, in this case along with a remote management system. Made in-house by Suncar, the LVDU’s HV counterpart, the Fusion HVDU, is connected to the batteries, DC-DC converter, AC charger, inverters, HV thermal systems and, optionally, the DC fast-charging system. It contains fuses for the HV components, along with insulation monitors, measuring points and short-circuit bars. According to Suncar, all the inputs and outputs are protected by fuses at both the positive and negative poles. “Every connected consumer and all the power sources are analysed with regard to their respective nominal and maximum power requirements, and the appropriate cables and fuses are selected for this,” Baettig explains. Fusion modules support system voltages up to 800 VDC, plus 12 and 24 V supply voltages. The Fusion 800M for example is rated for continuous currents of 500 A, although it has two connections that can handle 600 A for short periods along with others sized for smaller currents. The latter include four rated at 400 A, four at 150 A and six at 50 A. Fuses provide protection from short-circuits. The Fusion 800M weighs 20 kg fully assembled, it is protected from contaminants up to IP67 or optionally to a higher rating, and works in ambient temperatures from -40 to +85 oC. defined working cycle for specific construction machines such as mobile excavators. “Data analysis of dieselpowered machines was conducted to make an educated guess on the capacity needed,” Baettig says. “Furthermore, a measurement campaign helped to give us detailed insights into the power consumption of each actuator.” The ZE150W has a sophisticated integrated thermal management system for the battery, motors and power electronics. Baettig explains that the system makes use of separate liquid cooling circuits at different temperature levels, which are connected via heat exchangers and a heat pump in order to increase the vehicle’s overall energy efficiency. “Elevated ambient temperatures are accounted for by a powerful set of heat exchangers for liquid coolant and hydraulic fluid,” Baettig explains. “These coolers are resistant to the harsh environmental conditions on construction sites. “With regard to all the electrical
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