Electric current compensation circuit for brushless motors for reducing ripples in output torques during phase change
First Claim
1. An electric current compensation circuit for a multiple-phase burshless motor wherein said motor includes a DC power source for supplying power to the motor, a driver for driving the motor, a sensor for detecting a position of magnetic flux in the motor and thereby generating a feedback signal in the form of a compensation current;
- further wherein said electric current compensation circuit comprises a plurality of electric current compensation loops each for a respective phase and each of said electric compensation loops comprises;
a first input for receiving a line current from said driver;
a second input for receiving said compensation current;
a forward rectifying circuit for forwardly rectifying said line current and said compensation current and outputting a forwardly rectified compensation current;
a reverse rectifying circuit for reversely rectifying said line current and said compensation current and outputting a reversely rectified compensation current; and
a summation circuit for summing said forwardly rectified compensation current from said forward rectifying circuit and said reversely rectified compensation current from said reverse rectifying circuit and outputting a synthetic current to a phase winding of said motor;
whereby each time the phase is changed, said electric current compensation circuit is triggered so as cause said synthetic current to be sent to the motor to allow the motor to generate an output torque with reduced ripple.
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Accused Products
Abstract
An electric current compensation circuit for use with a multiple-phase burshless motor to reduce ripples in the output torque is disclosed. It contains a plurality of electric current compensation loops each for a respective phase winding and each of the electric compensation loops contains: (a) a first input for receiving a line current from the driver; (b) a second input for receiving the compensation current from the motor sensor; (c) a forward rectifying circuit for forwardly rectifying the line current and the compensation current; (d) a reverse rectifying circuit for reversely rectifying the line current and the compensation current; and (e) a summation circuit for summing the forwardly rectified compensation current and the reversely rectified compensation current and outputting a synthetic current to a phase winding of the motor. Each time the phase is changed, the electric current compensation circuit is triggered causing the synthetic current to be sent to the motor to allow the motor to generate an output torque with reduced ripple.
17 Citations
3 Claims
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1. An electric current compensation circuit for a multiple-phase burshless motor wherein said motor includes a DC power source for supplying power to the motor, a driver for driving the motor, a sensor for detecting a position of magnetic flux in the motor and thereby generating a feedback signal in the form of a compensation current;
further wherein said electric current compensation circuit comprises a plurality of electric current compensation loops each for a respective phase and each of said electric compensation loops comprises; a first input for receiving a line current from said driver; a second input for receiving said compensation current; a forward rectifying circuit for forwardly rectifying said line current and said compensation current and outputting a forwardly rectified compensation current; a reverse rectifying circuit for reversely rectifying said line current and said compensation current and outputting a reversely rectified compensation current; and a summation circuit for summing said forwardly rectified compensation current from said forward rectifying circuit and said reversely rectified compensation current from said reverse rectifying circuit and outputting a synthetic current to a phase winding of said motor;
whereby each time the phase is changed, said electric current compensation circuit is triggered so as cause said synthetic current to be sent to the motor to allow the motor to generate an output torque with reduced ripple.- View Dependent Claims (2, 3)
Specification