Patent ID: 8536811

Claim:
A motor controller for engaging a spinning motor, comprising: a power section configured to provide power to the motor; and a control configured to control the power section, wherein the control is configured to: search for a motor frequency of the motor by applying a small excitation voltage to the motor, wherein the excitation voltage is initially applied at a voltage frequency which is a maximum frequency; track the motor frequency until the motor frequency is below an equivalent speed command; and engage the motor by applying a higher voltage to the motor, wherein to determine a motor speed of the motor: the control is configured to transform a feedback current of the motor into a current vector, in which the current vector equates to the motor frequency of the motor; the control is configured to apply the voltage frequency to the motor, in which the control correlates the voltage frequency to a particular speed; and when the feedback current is zero, the control is configured to determine that the motor is spinning at the motor speed of the particular speed.