Patent ID: 6657413
Filing Date: 2003-12-02
Classification: H02P

Abstract:
A driving equipment for a synchronous motor, comprising:an inverter for converting a direct-current voltage to an alternating current or a direct current and supplying the current to said synchronous motor; a control apparatus for controlling the output voltage and frequency of said inverter; and a means for detecting or estimating the rotational speed of said synchronous motors; wherein said control apparatus is further equipped with a means for issuing a torque command that matches the rotational speed and a rotational speed command, and a means for receiving the torque command (T*) as an input signal, computing a current amplitude command (I*) and current phase command (&phgr;*), and sending the commands as output signals; said receiving, computing and sending means performs the computation of the current amplitude command (I*), and current phase command (&phgr;*) according to the following first and second linear functions using the torque command (T*) as a parameter; I*=AÂ·T*+B &phgr;*=FÂ·T*+G; and A, B, F and G are constants determined for the synchronous motors to maximize achievable torque with a minimum current.