A method for the automatic determination of a comparative value for the voltage commutation in the control of a brushless motor in the time-division multiplex at the end of a production run

摘要

The invention relates to a device and a method for determining a reference voltage (v_refu) for the generation of a commutation signal (a₁) for the commutation of a brushless dc motor. The brushless dc motor has a first example of the phase (u) of a plurality of phases (u, v, w) on. The device is at the end of the manufacture in a first prior parameterization phase, for example, is operated at the end of the band. An operating phase in the subsequent use of the engine follows: after. The device has a drive block (st), the phases (u, v, w) in the commutation intervals (φ₁ to φ₆) commutation and is supplied with current or not supplied with current. The first phase (u), in a first subset ({φ₁, Φ₂, Φ₄, Φ₅}) supplied with current, and in a second subset ({φ₃, Φ₆}), the freely running intervals, is not energized. A first dividing device (spt₁, spt₂, spt₃, Su_1U) generates a virtual star point signal (sps) of the phases (u, v, w). A second dividing device (su_2U) generates a corrected voltage signal (u_corr) as the difference between the first phase (u) and the current value of the virtual star point signal (sps). A first integrator (int_1U) the corrected voltage signal (u integrated_corr) during the freely running intervals to a first threshold value signal (s_1U) if it has a first predetermined polarity. Otherwise, it can be the first threshold value signal (s_1U) unchanged. A fourth integrator (int_2U) the corrected voltage signal (u integrated_corr) during the freely running intervals and only in the parameters homogenization phase to a fourth threshold value signal (s_2U). A first maximum value detector (min / max_U) in the parameters detected homogenization phase of the maximum of the fourth threshold value signal (s_2U) in a freewheel interval and storing it. In the operating phase, he adjusts the stored value as a first maximum signal (s_2Umax) a first comparator (cmp_1U) as a first reference voltage (v_refu) available. The first comparator (cmp_1U) thus, compares the first maximum signal (s_2Umax) as a first reference voltage (v_refu) with the first threshold value signal (s_1U). It generates the first commutation signal (a₁) as a function of the result of this comparison.