Sensorless control of a simulated BLDC motor. The triggered phase and freewheeling phase are simulated in current mode, the floating phase is simulated in voltage mode.
Drives with brushless direct current (BLDC) motors are popular because they are simple and robust. Often they are operated without any position sensors like Hall sensor and are used in continuously running pumps, electric fuel pumps, selective catalytic reduction (SCR) systems, and so on.
During the operation of BLDC motors only two of the three phases are triggered at a time. In the third, untriggered phase the electromotive voltage is induced, which affects the ECU terminals. In sensorless control, the ECU measures this voltage for position detection.
The dSPACE hardware-in-the loop simulator based on SCALEXIO equipped with a DS2655 FPGA Base Board and electronic load module enables the complete simulation of BLDC motors at electric power level. No real parts are required. Due to the characteristic of BLDC operation described above, the simulation comprises a current and also a voltage emulation.