| 摘要 |
A method for controlling a discharge pump of a household appliance, including starting a synchronous electric motor that actuates said discharge pump until the synchronism condition is reached, and driving said synchronous electric motor at a steady state through phase control by varying the firing angle (α). In driving said synchronous motor at steady state through phase control, said firing angle (α) is feedback controlled to cancel the phase difference between the mid-point of a zero current plateau of a function of the phase current fed to the electric motor and the zero-crossing point of a counter electromotive force signal (fcem) relative to the same phase. In feedback controlling the firing angle (α), the synchronous electric motor is switched off if the required firing angle (α) exceeds a maximum threshold (αlim), which may result from the operation of the discharge pump in air-water conditions. |
