Texas Instruments (TI) has introduced the TMCS2100-Q1 multiaxial coreless Hall-effect current sensor for hybrid electric vehicle (HEV) and electric vehicle (EV) traction inverters.
The sensor combines multiaxial magnetic-field measurement with a proprietary algorithm to improve current-sensing accuracy without requiring a magnetic core.
Unlike conventional coreless sensors that measure along a single axis, the TMCS2100-Q1 measures magnetic fields in both horizontal and vertical directions. TI says the approach is 20 times more accurate than single-axis alternatives, with displacement error below 1% at 0.4 mm of movement and as low as 0.25% at 0.1 mm.
Accurate current measurement is important to the traction inverter torque-control loop. Movement between the sensor and conductor caused by vehicle vibration can introduce measurement error in single-axis coreless designs. Measuring both magnetic-field components allows the TMCS2100-Q1 to compensate for that displacement while maintaining a compact coreless architecture.
This becomes increasingly important in higher-voltage EV powertrains, where traction inverter efficiency and torque control directly affect vehicle performance and energy use.
Traditional current-sensing approaches can require a trade-off between size and accuracy. Magnetic-core designs provide high accuracy at the expense of additional size and weight, while conventional coreless sensors can be more sensitive to displacement and magnetic crosstalk.
The TMCS2100-Q1 is designed to address these limitations by:
- Measuring horizontal and vertical magnetic fields simultaneously to reduce vibration-induced error.
- Minimizing magnetic crosstalk between motor phases for more accurate current measurement.
- Eliminating the need for busbar modifications such as notches, slots, or holes.
Hall-effect current sensors measure the magnetic field generated by current flowing through a conductor such as a busbar between the traction inverter and motor. Avoiding modifications to the busbar can simplify mechanical and thermal design while giving engineers more flexibility in sensor placement.
TI says improved current accuracy can reduce torque ripple and improve motor-control performance. The coreless architecture also allows the sensor to be incorporated into more compact traction inverter designs.
Production quantities of the TMCS2100-Q1 are available upon request. TI also offers an evaluation module, characterization module, and reference design for development and testing.
Filed Under: Sensors, Technology News