Author name: brogenevsolution.com

In-Depth Overview of Battery Thermal Management Systems for Electric Semi Trucks As electric semi trucks gain traction in global logistics, maintaining battery performance and safety under varied environmental conditions is critical. This is where the Battery Thermal Management System (BTMS) comes into play. 1. Introduction of BTMS for Electric Semi Trucks The Battery Thermal Management System (BTMS) in electric semi trucks is a closed-loop liquid cooling system composed of coolant circuits and thermal conductive media. By leveraging sensors and a control unit, the system actively regulates coolant temperature to keep the traction battery pack operating within an optimal thermal range. This ensures peak battery performance, extends service life, and enhances overall vehicle safety. 1.1 Key Functions of the BTMS Cooling: When battery cell temperatures rise excessively, the system activates cooling to prevent thermal runaway and potential safety incidents. Preheating: In low-temperature environments, the system preheats the battery cells to ensure safe and efficient charging/discharging operations. Temperature Equalization: It reduces internal temperature differences among cells, minimizing localized overheating and maintaining uniform battery performance. 1.2 Structure and Operating Principle The BTMS consists of the following major components: Liquid Cooling Unit: Provides pressurized, temperature-regulated coolant to the system. Expansion Tank: Manages fluid storage, replenishment, and thermal expansion. Coolant Pipes: Serve as channels for the antifreeze coolant and connect with the battery’s internal cooling plates to form a sealed loop. Antifreeze Coolant: Acts as the heat transfer medium. Two common layout configurations exist for the cooling unit – top-mounted or bottom-mounted on the battery pack. The expansion tank is located on the top of the battery pack. System interfaces include 1 observation window, 2 coolant ports, and 3 electrical connectors. 1.3 System Schematic and Configurations (Examples) 282 kWh Battery System (Charging or Swappable Version): Consists of four H-type modules arranged in a 2-parallel x 2-series configuration. 350 kWh Battery System (Charging or Swappable Version): Includes ten C-type modules arranged in a 5-parallel x 2-series configuration. 2. Liquid Cooling Unit: Three Thermal Circuits The battery thermal management relies on three interlinked circuits: Liquid Cooling Circuit: Electric water pump, plate heat exchanger, battery cooling channels Refrigerant Circuit: Compressor, condenser, expansion valve, plate heat exchanger Air Circuit: Electric fan, condenser There are two heat exchange interfaces: Plate Heat Exchanger: Enables heat transfer between the refrigerant loop and the liquid cooling loop. Condenser: Transfers heat between the refrigerant loop and the air circuit. Key Components and Functions Integrated Controller: This unit combines three control modules – PLC, DC-DC, and DC-AC – in one compact system. It collects data from high-pressure and low-pressure sensors, as well as inlet and outlet temperature sensors. The controller receives operational commands and target coolant temperatures from the BMS, enabling precise control over the operation of the electric water pump, compressor speed, and electric fan speed. Compressor: A core component of the refrigerant circuit, the compressor is responsible for absorbing, compressing, and discharging the refrigerant to maintain circulation. The cooling capacity of the liquid cooling loop depends on the proper functioning of the compressor. Electric Water Pump: It drives the circulation of antifreeze within the liquid cooling loop. It plays a vital role in transferring heat away from the battery cells through the liquid-cooled plates. Without proper pump operation, battery cooling cannot be achieved effectively. Electric Fan: Mounted on the exterior side of the condenser, this suction-type fan delivers continuous airflow across the condenser surface, dissipating the heat absorbed by the refrigerant. If the fan fails to operate correctly, the system may experience pressure faults due to insufficient heat dissipation. Condenser: The condenser transforms high-temperature, high-pressure gaseous refrigerant into a high-pressure liquid state. If the condenser becomes clogged or dirty, airflow is reduced, leading to decreased heat transfer efficiency and diminished cooling capacity. This results in minimal temperature difference across the coolant circuit and continuous temperature rise in battery cells, which may trigger system pressure alarms. Regular cleaning and maintenance of the condenser are essential for safe operation in electric vehicles. Plate Heat Exchanger: This component facilitates thermal exchange between the low-temperature refrigerant and the high-temperature antifreeze. After passing through the exchanger, the antifreeze temperature typically drops by 2°C to 5°C under normal operating conditions. Expansion Valve With Thermal Sensing Bulb: This valve converts the refrigerant from a medium-temperature, high-pressure liquid into a low-temperature, low-pressure liquid. The thermal sensing bulb detects temperature inside the cooling pipe and adjusts the valve’s operating accordingly to regulate refrigerant flow. Due to its high sensitivity to temperature fluctuations, the expansion valve and thermal bulb are insulated with protective layers. Sensors: High-pressure and low-pressure sensors monitor pressure levels within the refrigerant circuit. Inlet and outlet temperature sensors measure coolant temperatures at the water inlet and outlet of the liquid cooling unit. These signals are sent to the PLC controller, which uses the data to dynamically manage the operation and speed of the compressor, water pump, and fan, ensuring stable and efficient thermal regulation. Our Battery Thermal Management Solutions for Electric Semi Trucks At Brogen, we provide tailored EV battery systems along with BTMS solutions. For electric semi-trucks and other heavy-duty vehicles, we offer standard 272 kWh and 350 kWh battery systems, paired with BTMS units ranging from 5 kW to 10 kW. The thermal units feature a lightweight aluminum alloy frame and can be optionally equipped with PTC liquid heaters. They support multiple operation modes, including standby, cooling, heating, and self-circulation. Communication is based on the CAN bus protocol, with built-in self-diagnosis, real-time status monitoring, and fault reporting capabilities. In addition, we offer integrated thermal management solutions tailored to customer requirements. These systems share components, such as the compressor and condenser, between the air-conditioning circuit and the battery cooling system. The architecture includes dual evaporator circuits: one for cabin climate control and the other for battery temperature regulation. The battery cooling loop uses a secondary liquid-cooling heat exchange approach to ensure efficient and stable thermal performance. Technical Parameters Model OETLE205 OETLE207 OETLE208 OEEFDR-01 OEEFDR-02 OEEFDR-03 OEEFDR-04 Cooling capacity 5 kW 7 kW 8 kW 3 kW 5 kW

Installation Requirements for Onboard Charger (OBC + DCDC) 1. General Requirements The onboard charger layout must take into full consideration its mechanical and electrical characteristics, adhering to principles such as ease of assembly/disassembly, system size, cost minimization, and strong electromagnetic compatibility. 2. Positioning Requirements for the Onboard Charger System-level considerations: The orientation of the OBC should be determined based on its function and characteristics, especially the direction of current flow and coolant piping. Sufficient installation space: A minimum clearance of 10 mm must be maintained between the OBC and surrounding components. Proximity principle: The wiring harness connections between the OBC and components such as the charging port, PDU, traction battery, and auxiliary battery should be as short as possible. Avoid placement near areas of high temperature or excessive moisture. 3. Mounting Requirements for the Onboard Charger The OBC should be mounted in a location that allows convenient removal, preferably without the need to lift the entire vehicle. Adequate tool access space must be reserved around all mounting points. 4. Connector Position Requirements Connectors should be positioned as close as possible to the electrical components they are wired to. The space reserved in the direction of the connector should be at least three times the length of the connector itself, while also ensuring the wiring harness has a sufficient bending radius (greater than 5 times the diameter of the harness). 5. Coolant Circuit Requirements The highest point of the OBC coolant circuit should be lower than the reservoir tank. Inlet and outlet hose positions should be oriented according to the direction of coolant flow and placed as close as possible to the corresponding components. For horizontal installations, either side may serve as the inlet/outlet; for vertical installations, coolant should flow bottom-in, top-out. The OBC should be positioned upstream of the EDS in the cooling loop. 6. Crash Safety Requirements The OBC should be located away from high-risk collision zones. 7. Vibration Requirements The OBC must be positioned away from direct vibration sources such as the engine or suspension system. The vibration standard for the onboard charger (when installed on body-mounted components above dampers) is an RMS acceleration of 30.8 m/s². 8. Dimensional Chain Requirements If the OBC mounting bracket consists of multiple parts and is a newly developed component, dimensional chain analysis must be conducted, and mounting hole specifications should be defined accordingly. For existing (carry-over) parts, the design must control dimensional chain deviations to ensure the mounting hole dimensions meet installation requirements. About Brogen At Brogen, we provide advanced EV solutions for global commercial vehicle manufacturers, enabling them to streamline research and development while capitalizing on cutting-edge technology. Our offerings ensure superior efficiency, extended range, and seamless system integration with proven reliability—empowering our partners to lead in the rapidly evolving green mobility landscape. Currently, our EV solutions have been adopted by vehicle manufacturers in countries and regions such as Canada, Türkiye, Brazil, the Philippines, Indonesia, the Middle East, and more. Discover our Onboard Charger & DCDC solutions here: https://brogenevsolution.com/obc-dcdc-pdu/ Looking for an EV solution for your project? Reach out to us at contact@brogenevsolution.com Contact Us Get in touch with us by sending us an email, using the Whatsapp number below, or filling in the form below. We usually reply within 2 business days. Email: contact@brogenevsolution.com Respond within 1 business day Whatsapp: +8619352173376 Business hours: 9 am to 6 pm, GMT+8, Mon. to Fri. LinkedIn channel Follow us for regular updates > YouTube channel Ev systems introduction & industry insights > ContactFill in the form and we will get in touch with you within 2 business days.Please enable JavaScript in your browser to complete this form.Please enable JavaScript in your browser to complete this form. Name * FirstLast Work Email *Company Name *Your Project Type *– Please select –Car, SUV, MPVBus, coach, trainLCV (pickup truck, light-duty truck, etc.)HCV (heavy-duty truck, tractor, trailer, concrete mixer, etc.)Construction machinery (excavator, forklift, crane, bulldozer, loader, etc.)Vessel, boat, ship, yacht, etc.Others (please write it in the note)Your Interested Solutions *– Please select –Motore-AxleBatteryChassisAuxiliary inverterOBC / DCDC / PDUAir brake compressorEPS / EHPS / SbW / eRCBBTMSOthers (please write it in the note)Do you have other contact info? (Whatsapp, Wechat, Skype, etc.)Please introduce your project and your request here. * Checkbox * I consent to receive updates on products and events from Brogen, and give consent based on Brogen’s Privacy Policy. Submit

HVIL Explained: What It Is and Why It’s Critical for High-Voltage Safety With the rapid development of electric vehicles (EVs), especially the increasing demand for fast charging, the operating voltages used in EVs are steadily rising. While some models still use a 200 V platform, the mainstream adopts 400 V systems, and high-end vehicles are increasingly equipped with 800 V architectures. Some OEMs are now developing even higher voltage platforms of 900 V to 1000 V to support ultra-fast 6C charging. As voltage levels increase, concerns about high-voltage safety in EVs grow accordingly. 1. Safety Challenges Associated with High Voltage The primary safety risk associated with high voltage is electric shock, particularly when high-voltage components become exposed. Besides shock hazards, two other major safety issues related to high-voltage operation are switch arcing and high-voltage power loss. 1.1 High Voltage Exposure The generally accepted safety thresholds for human exposure are approximately 50 VAC or 120 VDC. However, actual safety depends heavily on the environment, contact duration, and body resistance. For example, voltages below 36 VAC or 60 VDC are considered relatively safe in dry conditions, but in wet or conductive environments, safe voltages drop to 12 V to 24 V. Mainstream EV high-voltage systems operate around 400 VDC, far exceeding these safety levels. Exposure to such voltages presents serious risks. To mitigate this, all high-voltage components are enclosed in insulated protective covers. These protective covers must remain securely closed during vehicle operation; any unauthorized opening must be detected and addressed immediately. 1.2 Switch Arcing High-voltage switches, such as connectors, can generate electric arcs when opened or closed under load. This occurs because when the voltage exceeds the breakdown voltage of the surrounding gas or insulation medium, electrons accelerate and ionize surrounding particles, causing an avalanche effect that sustains an electric arc. Such arcs can severely damage switch contacts and pose fire hazards to nearby components and personnel. 1.3 High-Voltage Power Cutoff In traditional vehicles, power is provided by an internal combustion engine. When the engine encounters issues – such as high coolant temperature, emission faults, or operational failures – early warnings and appropriate handling are required. In electric vehicles, propulsion is driven by high-voltage electricity from the power battery to the motor. If high-voltage power is suddenly cut off while the vehicle is in motion, it can result in a complete loss of power, posing safety risks to both the vehicle and its occupants. Therefore, early warnings and safety mechanisms must be in place. Issues such as high-voltage exposure, switching arcs, and unexpected high-voltage disconnection must be detected, monitored, and handled effectively to prevent related safety incidents. The High-Voltage Interlock Loop (HVIL) is a safety mechanism capable of addressing all of these concerns simultaneously. 2. Basic Concept of HVIL HVIL stands for High Voltage Interlock Loop – a safety system designed to monitor the integrity of the high-voltage circuit using a low-voltage signal loop. It continuously checks the connection status of all high-voltage components and wiring harnesses, ensuring the entire system remains intact and safe. HVIL systems typically cover critical components such as the battery pack, Battery Management System (BMS), Vehicle Control Unit (VCU), Power Distribution Unit (PDU), Motor Control Unit (MCU), DC/DC converter, PTC heater, wiring harnesses, connectors, and protective covers. When a fault or disconnection occurs anywhere in the HVIL loop, the system triggers alarms and initiates safety measures. 3. How HVIL Works 3.1 Mechanical Structure As previously mentioned, switch arcing is a common issue in high-voltage systems during operation. In electric vehicles, the primary switches that require connection and disconnection are high-voltage connectors, namely, plugs and sockets. If these connectors are plugged or unplugged while live, arcing can easily occur. This problem is addressed through specialized mechanical design. Standard connectors typically have only two terminals: one for the high-voltage positive and one for the negative. HVIL connectors, however, include an additional pair of low-voltage terminals – positive and negative – used by the HVIL system to monitor circuit integrity. These are referred to as HVIL pins. HVIL Connectors As shown in the diagram above, the HVIL connector features four terminals, with two additional HVIL pins located in the center. The illustration on the right further shows that the contact points of the central HVIL pins are not on the same plane as those of the HV pins on either side. The HVIL pins are shorter, which means that during connection, the HV pins make contact first, followed by the HVIL pins. Connection Sequence and Disconnection Sequence The connection process proceeds from left to right: In the left image, all four pins are fully disconnected. In the middle image, the two HV pins on either side make contact first, while the central HVIL pins are not yet connected. In the right image, the HVIL pins complete the connection, finalizing the engagement of all four terminals. If the HVIL pins detect an abnormal condition, the high-voltage circuit is immediately interrupted. When the HVIL pins are not connected, the system is in an open-loop state – considered abnormal – and the internal circuit will cut off the high-voltage supply. Therefore, before the HVIL pins engage, the high-voltage circuit remains open, preventing any voltage presence and eliminating the risk of arcing. This design ensures safety during connector engagement. The disconnection process occurs in reverse order, from right to left: the HVIL pins disconnect first, followed by the HV pins. Once the HVIL pins open the circuit, the high-voltage power is immediately cut off, ensuring that when the HV pins are separated, no voltage is present – thus guaranteeing safe disconnection. 3.2 Electrical Principle While the issue of switch arcing can be addressed through specialized mechanical design, verifying the integrity of the high-voltage circuit requires an electrical solution. Sample Schematic Diagram of the HVIL Circuit The diagram above illustrates a sample HVIL system, which uses a dedicated HVIL monitoring unit. This unit is connected in series with the HVIL pins of the BMs, MDI, and OBC modules, forming a closed monitoring loop.

Five Key High-Voltage Safety Design Principles in Electric Vehicles In battery electric vehicles (BEVs), the propulsion system is powered by high-voltage electric motors. These systems typically operate at very high currents—ranging from tens to even hundreds of amperes—and in the event of a short circuit, the current can spike dramatically. Such high voltages and currents pose significant safety risks to both passengers and vehicle components, including electrical systems and control units. Therefore, the high-voltage electrical system in an EV must not only meet performance and power delivery requirements but also ensure operational safety, personal safety, and safe maintenance. Effective high-voltage safety management involves a combination of technical design, operational protocols, protection mechanisms, and user safety education. Below are five fundamental safety design principles widely adopted in EVs to ensure safe handling and operation of high-voltage systems: 1. Leakage Current Protection Electric vehicles are equipped with leakage current protection devices. If either the positive or negative high-voltage bus comes into contact with the vehicle chassis, the protection device will trigger an alert—or in many cases—automatically shut down the high-voltage supply. This prevents scenarios where the motor casing becomes electrically charged, which could lead to an electric shock if someone touches the opposite pole. Leakage protection also safeguards systems such as the air conditioning unit and DC/DC converters from high-voltage leakage. 2. High-Voltage Interlock (HVIL) All high-voltage connectors are designed to prevent disconnection while the system is energized. However, to guard against human error or unauthorized tampering, high-voltage interlock (HVIL) switches are integrated into connectors. If a connector is unplugged, the interlock circuit is immediately interrupted. The system controller detects this and rapidly disconnects the main relay, cutting off high-voltage power in milliseconds—thereby preventing potential electric shock. HVIL is a critical fail-safe in high-voltage circuit design. 3. Collision Power Cutoff In the event of a collision, onboard crash sensors immediately send a signal to trigger the HVIL system. This automatically disconnects the vehicle’s high-voltage power supply to protect occupants from electric hazards. Some modern systems integrate this function directly into the high-voltage connector modules, combining sensing and cutoff in a compact unit. 4. Insulation Resistance Monitoring Higher system voltages require stricter standards for insulation to prevent dangerous leakages. Insulation resistance is a critical safety parameter, with regulatory standards clearly defining minimum thresholds to mitigate risks of electric shock or component failure. Two common methods are used to monitor insulation resistance: Auxiliary Power Method:A 110V DC auxiliary battery is connected across the high-voltage circuit (positive to negative, and negative to vehicle ground). Under normal conditions, no current flows. If insulation is compromised—due to aging, moisture, etc.—a leakage current forms, triggering an alert and shutting down the system. While effective, this method increases system complexity and cannot easily identify whether the issue lies in the positive or negative lead, limiting its application in EVs. Current Sensor Method:Hall-effect current sensors measure differential current flow by passing both positive and negative cables through the same sensor. When no leakage is present, the outgoing and returning currents cancel out, and the sensor reads zero. If leakage occurs, the imbalance is detected, and the direction of current flow helps identify whether the fault is on the positive or negative side. This method requires the system to be powered during testing but is more commonly used in modern EVs due to its efficiency and precision. 5. Access Panel Monitoring Certain critical high-voltage components in EVs are equipped with cover monitoring mechanisms. If a cover is opened while the high-voltage system is still active, a signal is sent to the main controller. The controller immediately cuts off the main relay and activates a discharge mechanism that rapidly reduces internal voltage to safe levels. This feature ensures safety during servicing or accidental opening of enclosures. Conclusion High-voltage safety is foundational to electric vehicle design. From real-time system monitoring to automatic disconnection features, these protective measures are vital for ensuring the safety of passengers, maintenance personnel, and the vehicle itself. As EV technology continues to evolve, robust safety protocols will remain essential in supporting the growth of safe and reliable electric mobility. About Brogen At Brogen, we provide advanced EV solutions for global commercial vehicle manufacturers, enabling them to streamline research and development while capitalizing on cutting-edge technology. Our offerings ensure superior efficiency, extended range, and seamless system integration with proven reliability—empowering our partners to lead in the rapidly evolving green mobility landscape. Currently, our EV solutions for battery electric buses and trucks have been adopted by vehicle manufacturers in countries and regions such as Australia, Türkiye, Brazil, the Philippines, Indonesia, the Middle East, and more. Looking for an EV solution for your project? Reach out to us at contact@brogenevsolution.com Contact Us Get in touch with us by sending us an email, using the Whatsapp number below, or filling in the form below. We usually reply within 2 business days. Email: contact@brogenevsolution.com Respond within 1 business day Whatsapp: +8619352173376 Business hours: 9 am to 6 pm, GMT+8, Mon. to Fri. LinkedIn channel Follow us for regular updates > YouTube channel Ev systems introduction & industry insights > ContactFill in the form and we will get in touch with you within 2 business days.Please enable JavaScript in your browser to complete this form.Please enable JavaScript in your browser to complete this form. Name * FirstLast Work Email *Company Name *Your Project Type *– Please select –Car, SUV, MPVBus, coach, trainLCV (pickup truck, light-duty truck, etc.)HCV (heavy-duty truck, tractor, trailer, concrete mixer, etc.)Construction machinery (excavator, forklift, crane, bulldozer, loader, etc.)Vessel, boat, ship, yacht, etc.Others (please write it in the note)Your Interested Solutions *– Please select –Motore-AxleBatteryChassisAuxiliary inverterOBC / DCDC / PDUAir brake compressorEPS / EHPS / SbW / eRCBBTMSOthers (please write it in the note)Do you have other contact info? (Whatsapp, Wechat, Skype, etc.)Please introduce your project and your request here. * Checkbox * I consent to receive updates on products and events from Brogen, and give consent based on Brogen’s Privacy Policy. Submit