​OBC

Electrical drive and control

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| Application Introduction

      OBCs are used only for AC charging, converting AC power from charging stations to DC to charge the battery. Charging speed depends on OBC power rating. Temperature sensors monitor internal power devices to prevent charging abnormalities due to overheating.​Power NTCs connected in series to the AC input line effectively suppress inrush currents. Alternatively, power PTCs can be used with relay support for similar protection.

      Charging sockets are also monitored in real time by temperature sensors. Frequent use and exposure to environmental factors (e.g., moisture, dust) may cause poor connections and abnormal heating. Temperature detection helps prevent hazards like melting contacts, plastic degradation, or fire.

| Product Application Solutions

SENSOR_CNSA Series / SENSOR_CNSF Series

Electrical terminal structure

Clip+Metal Probe Structure

Onboard plug-in NTC

The temperature detection of OBC power devices generally uses electrical terminal type sensors attached to the heat sink, while liquid cooled OBC uses Clip+metal head temperature sensors or onboard plug-in NTC in liquid cooled pipelines.

SENSOR_CNSA Series / SENSOR_CNSF Series

Electrical terminal structure

Metal head temperature sensor

During high-power charging, charging sockets may pose a risk of overheating. The temperature sensor effectively prevents severe safety incidents such as metal melting, plastic component burning, and even fires caused by interface overheating. This ensures an efficient heat dissipation system and secure physical connection during the charging process.

Over-current​ protection

Power type NTC/PTC thermistor

At the moment when the OBC is powered on and starts charging the battery, the large capacity input filtering capacitor inside will generate a huge surge current. On the AC input line connected in series with power type NTC, the generation of surge current can be effectively suppressed. At the same time, power type PTC can also be used for the same protection, but when using PTC, relay phase assistance is required.

TLMOV thermal protection type varistor

Thermal Link & MOV 

OBC is directly connected to the power grid and is most susceptible to attacks from surge voltage and lightning induced surges from the grid. Varistors are usually connected in parallel between the live and neutral wires of the AC input, as well as between them and the ground wire, to absorb these external transient overvoltages and prevent damage to important components such as rectifier bridges, PFC circuits, and switching devices.