Global Dealer Learning - BEM Systems

Global Dealer Learning - Battery Electric Machine Systems

• This module covers the fundamentals of Battery Electric Machine (BEM) systems.
• Caterpillar products are covered, including the R1700 XE, 950 GC, and 906.
• The document provides detailed tables of contents for different modules within the learning program.
• A safety briefing is included, covering emergency numbers, first aid responders, location of exits, fire extinguishers, room alerts, evacuation locations, storm shelters, and hazardous materials.

Purpose

• The purpose of this module is to explain the components of Battery Electric Machine (BEM) systems.

Reason

• Successful completion validates knowledge, skills, and behaviors required to determine the location, function, and operation of BEM system components.

Assessment Criteria

• Knowledge assessment is conducted through a closed-book exam.
• Minimum passing score is 80%.

Learning Outcomes

• Participants will be able to identify BEM system components.
• Participants will be able to describe the function of BEM system components.
• Participants will be able to explain BEM system and component operation.

BEM Systems Overview

• BEM systems utilize stored battery power, discharged through a Power Electronics Module (PEM).
• The PEM connects the battery system to charging systems and HaV electrical systems.
• The illustration shows one battery box of a R1700 XE LHD, the other is located opposite the illustrated one.

Ground Level Service Center

• HaV indicator lamp monitors DC bus voltage, regardless of the low voltage system's battery disconnect switch.
• When hazardous voltage is present, the amber lamp is illuminated.

Electrical Isolation

• HaV components and their housings are electrically isolated to prevent contact with hazardous voltages during servicing.
• Components and their assemblies are sealed to prevent moisture, oil and other contaminants.

Bonding and Grounding Wire System

• HaV components are connected by bonding wires.
• Component housings are grounded to the machine frame using grounding wires.
• All component housings are at the same electrical potential as the machine frame.

Hazardous Voltage (HaV) Cables

• Orange-clad HaV cables are used to convey power to HaV components.
• Stranded stainless steel wire overbraids strengthen cables and provide protection.
• Ground fault detection features protect users and components.

Cat Battery Pack

• Consists of three main components: battery modules, a Power Electronics Module (PEM), and a Battery Management System (BMS).
• Modules are connected in series to increase voltage, or in parallel to extend the time period electric power can be supplied, depending on type.
• The PEM connects the battery modules to the machine's HaV electrical system.

R1700 XE 715 VDC Battery System

• A distinct battery system from other BE machines.
• The HaV junction box acts as both PEM and PDU.
• The battery system supplies 715 VDC to the HaV electrical system.
• It has three main components: a battery pack, HaV junction box, and a BMS.

DC Charging System

• Battery electric machines use a DC charging system.
• The R1700 XE LHD has a charger receptacle box with two DC charger ports for connection to a Mobile Equipment Charger (MEC) unit.

AC Charging System

• Battery electric machines, other than the R1700 XE LHD, have an AC charging system.
• Port types vary by region (Type 1 for US, Type 2 for EU).
• AC voltage is rectified into DC voltage before entering the PDU.

Power Distribution Unit (PDU)

• The PDU distributes electric power from the battery to inverters and DC/DC converters.
• It also supplies power to auxiliary components.
• The R1700 XE LHD and 50V battery pack functionality.

Inverter

• Converts DC voltage to AC voltage for supplying electric power to motors.

Propulsion Motor

• Converts electric power into mechanical power for propelling the machine.
• The type and design of the motor depend on the specific machine model (e.g., 906, 950 GC, or R1700 XE LHD).

Pump Motor

• Converts electric power into mechanical power to drive hydraulic pumps.
• Designs and constructions vary depending on the machine model (e.g., 906, 950 GC, or R1700 XE LHD).

DC/DC Converter

• Converts high-voltage DC to low-voltage DC for powering lower-voltage parts of the BE machine.

Auxiliary Components

• Additional components supplied by PDU may include optional cab heaters, PTC heating elements, A/C compressors, and thermal management systems.
• 301.9 MiniHEX cab heater connects to the 50V battery pack PEM.

Battery System Control

• Two main electronic control systems (BMS and Electric Drive Control System) are part of the battery electric machine systems.
• BMS monitors battery modules, HaV junction boxes, and charging systems, overseeing the charging and discharging of the battery and the function of accompanying components.

HaV Electrical System Control

• Provides monitoring and control of HaV electrical components for different battery electric machine types (e.g., R1700 XE LHD, 301.9 MiniHEX, 906 CWL, 950 GC MWL).

Powertrain Control

• The ECMs responsible for each machine's powertrain oversee all powertrain functions.

Battery System Cooling

• Systems for different models (R1700 XE LHD, 950 GC) control battery temperatures.

HaV Electrical System Cooling

• Cooling systems for different models (R1700 XE, 906 CWL, 950 GC) manage HaV component temperatures.

Motor Cooling and Lubrication

• R1700 XE LHD systems and and similar cooling systems maintain components within the output transfer box.
• Systems employ separate coolant systems to cool and lubricate various parts.

Propulsion Mode

• A mode for power from the battery system to send DC voltage to HaV electrical systems to enable vehicle propulsion.
• Processes in different models (906, 950 GC, or R1700 XE LHD) are examined.

Charge Mode

• A mode to charge Cat battery packs.
• Different models (e.g., R1700 XE, 301.9 and 320, and 906, 950 GC) charging systems are examined.

Retarding Mode

• Systems in different models use the propulsion motor's HaV systems as generators to reduce speed on downhill operation.
• Battery status is checked and components are controlled.

Module Conclusion

• Summary of the BEM system module for use with service manuals.