EV On-Board Chargers (OBCs)
What is an On-Board Charger (OBC)?
An On-Board Charger (OBC) is a crucial component in electric vehicles (EVs) that converts the AC (alternating current) electricity from the grid into DC (direct current) electricity, which is then used to charge the vehicle's battery. This conversion process is essential for efficient and safe charging of EVs. Without an OBC, the vehicle would not be able to utilize the electricity from standard power outlets or charging stations.
LEM's advanced current sensors play a crucial role in enhancing the performance and reliability of automotive OBCs. By providing accurate current measurements and ensuring the safety of the charging process, LEM's sensors are a key component in the future of electric mobility.
Key Functions and Benefits of On-Board Chargers in Electric Vehicles
On-board chargers serve several important functions in electric vehicles.
Firstly, they ensure that the vehicle's battery is charged efficiently, maximizing the energy transfer from the grid to the battery. This efficiency is critical for reducing charging times and improving the overall user experience. Additionally, EV OBCs incorporate various safety features to protect the vehicle's battery and electrical systems during the charging process. These safety measures include monitoring the temperature, voltage, and current to prevent overcharging and overheating.
Another significant benefit of on board charger ev is their versatility. They allow EVs to be charged from standard household outlets or dedicated charging stations, providing flexibility for users. This means that EV owners can charge their vehicles at home, at work, or at public charging stations, making it more convenient to keep their vehicles powered up.
Furthermore, on board chargers are designed to work seamlessly with the vehicle's battery management system (BMS) and other onboard electronics, ensuring smooth, reliable and safe operation.
The shift towards bi-directional On-Board Charging (OBC) systems is the next big trend in the EV on-board chargers industry. These systems enable EV batteries to be used as power sources for various applications (V2X), highlighting the need for advanced type B RCM sensors with ISO 26262 ASIL B compliance and adherence to the new ISO 5474 norm.
LEM's Innovative Solutions for Efficient and Safe On-Board Charging
LEM is at the forefront of providing innovative solutions for OBC applications.
Our current sensors are integral to the performance and safety of EV OBCs. LEM's sensors provide precise current measurements, which are crucial for the efficient operation of the EV on board chargers. Accurate current measurement ensures that the OBC can optimize the charging process, delivering the right amount of current to the battery without causing damage or reducing the battery's lifespan.
In addition to enhancing efficiency, LEM's sensors play a vital role in ensuring the safety of the charging process. By monitoring and managing the electrical currents, our sensors help prevent issues such as overcharging, overheating, and short circuits. This added layer of safety is essential for protecting both the vehicle and its occupants.
Moreover, LEM's solutions are designed to withstand the demanding conditions of automotive applications, offering long-term reliability and performance. This durability is particularly important in the automotive industry, where components must endure harsh environments and rigorous use.
The role of LEM Current Sensors in On Board Charger EV Operations
LEM's current sensors are used in various stages of the EV on board charger operation.
At the input stage, they monitor the AC input current to ensure it is within safe limits. This monitoring helps prevent issues such as power surges and fluctuations that could damage the OBC or the vehicle's electrical system.
During the conversion stage, LEM's sensors measure the DC output current to optimize the conversion process. Accurate measurement at this stage is crucial for maximizing the efficiency of the automotive obc and ensuring that the battery receives the correct amount of current.
On-board chargers block diagram
At the battery interface, LEM's sensors ensure that the correct current is delivered to the battery for safe and efficient charging. This precise control helps maintain the health and longevity of the battery, which is one of the most critical components of an electric vehicle. By providing accurate and reliable current measurements, LEM's sensors contribute to the overall performance and safety of the on board charger, making them an essential part of the EV charging process.
Pioneering Residual Current Monitoring with CDT Sensors
One of our latest innovations is the CDT sensor, which is specifically engineered for bi-directional OBCs. This sensor ensures compliance with the ISO5474 Part 2 standard for AC power transfer, addressing the safety challenges associated with bi-directional charging.
The CDT sensor is capable of detecting and monitoring residual currents, including both AC and DC leakage currents, which is crucial for maintaining the safety and integrity of the charging process.
CDT Series
- Automotive qualified
- Up to 48 A RMS current per primary conductor
- Primary current measurement range: ±300 mA DC
- Excellent accuracy
EV ON BOARD CHARGERS’ PRODUCTS
In addition to the CDT range, which can be used for current leakage detection, other product ranges can be used in automotive OBC applications, notably to ensure applications such as control loop, power fuel cell, or secondary DC/DC.
| ||||
|---|---|---|---|---|
| Application | Leakage detection | Control Loop | Power Fuel Cell Secondary DC/DC | Control Loop |
| Bandwidth | 2kHz – 100kHz | 300 kHz | 500kHz | 300 kHz |
| Consumption | 60mA | - | 15mA | 20mA |
| Current Range Max | 48A Per Phase ± 300mA (leakage) | ± 75A | ± 300A | ± 75A |
| Supply Voltage | +5V | +5V / 3.3V | +5V | +5V / 3.3V |
| Mounting | 1 Phase - 2 Jumpers 3 Phases - 4 Jumpers | SOIC 8 or 16 | Integrated Busbar | SOIC 16 |
| Output | SPI + Analog Tripping Output | Analog | Voltage | Digital, Analog |
| Overall Accuracy | 10% @ 5mA | 1.3% - 3% | 3.2% | 1.3% - 3% |
| Technology | Fluxgate | Current Sensor IC | Open Loop | Current Sensor IC |
Quality
LEM products adhere to the highest quality standards required by the automotive industry and comply with RoHS specifications. Our production and development centers in Switzerland and China are ISO TS 16949 certified. Leveraging our extensive expertise in applications and current measurement technologies, LEM offers both catalog and customized products that can be precisely tailored to meet your specific needs in terms of performance, space requirements, and cost.
PRODUCT DOCUMENTATION
Explore LEM’s cutting-edge technologies for automotive applications. Our expertise extends beyond On-Board Chargers to include innovative solutions for motor control and battery management systems (BMS).
For a comprehensive overview, download our brochure and discover the full range of our automotive solutions:
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