LEM Automotive specializes in developing and manufacturing current transducers for battery management and motor drive applications in cars, buses and trucks. By controlling the current in energy-intensive applications, LEM participates in the global effort to reduce overall energy consumption.

LEM products meet all quality requirements for the automotive industry and comply with RoHS specifications. All our production and development centers are certified with ISO TS 16949 (in Switzerland and in China). Based on our deep knowledge of applications and current measurement technologies, LEM develops both catalog and customized products which can be perfectly tailored to meet your needs in terms of performance, space requirement and cost

Applications for Automotive transducers :

• Transducers for Standard battery monitoring
• Hybrid and EV battery pack current sensing
• Transducers for Fuel cell current control
• Transducers used in DC/DC converters and AC/DC inverters
• Transducers used in Hybrid and EV motor inverter drive
• Transducers used in EPS and X-by-wire applications
• Transducers used in Electric compressors for air conditioning

Automotive: battery management

Conventional battery management :

Car makers have been focusing their attention on reducing fuel consumption for several years. Currently, the main focus is to reduce fuel usage by managing the charging of the main battery. Early progress in energy management has now shifted focus and is heavily concerned with power management. This includes managing the battery, the combination of additional functions of the battery’s state of health and safety features, such as auto-disconnect. Secondary functions have been reduced and the size of the alternator has been optimized thus instantly reducing global electrical consumption.

Battery management for hybrid and EV markets:

The production of electric car and hybrid vehicles is increasing. Both types of vehicle need high current capability batteries to run the 50kW or more motors and these use high voltage systems. The current sensors for these batteries need to be isolated. Hall-effect sensors are the product of choice for this application. The DHAB for the main current and the HC2 for the cell current are suited to accurate and fully isolated current sensing.

Current Transducers for Electric and hybrid vehicle motor converter

Production of electric and hybrid vehicles is increasing. Both have power motors (50kW or more) and use 3 to 6 phase inverters to drive the traction and generator motors precisely and reliably. The trend is to opt for high frequency and smooth wave forms, which is fuelling demand for fast current sensors. There are two distinct market needs:

• For standard products such as HC6 and HAH1DR family
• For a full custom solution which fits with the mechatronic approach

If you would like further information regarding electric hybrid vehicle motor converters, please do not hesitate to contact our technical staff, who will be happy to advise you about LEM’s standard and custom solutions in this field.

Other motor inverters : There is a huge volume of various motors that require current sensing. Typical applications include power steering, brake by wire, active suspension and electric compressors with currents that can vary from 20A up to 200A. LEM provides a whole range of products to cover these applications within the HC2 family. We are currently working on innovative standard and custom solutions that are due to be launched in the coming months.

Energy Conversion

Generator current monitoring : The need for higher energy in cars is increasing. Generators are required to provide more current to the vehicle loads and batteries, yet to be more efficient, the current needs to be controlled. The HAB and HAG current sensor families are best suited to provide the BMS (Battery Monitoring System) with the proper current information. Depending on the size of the car, this current can flow from 60A (conventional car) up to 240A (service cars and trucks).

DC/DC power converters : Environmentally-friendly cars and trucks require different levels of voltage; most loads run under 12V or 24V while the traction motors need a much higher voltage. There is a need to build efficient step-up and step-down converters in the car to make these different voltages available. The tendency is to have high frequency resonant converters which need fast current transducers.

The HC2, HC6 and HAH1DR families can handle the speed needed to meet these requirements.