Patent ID: 6326747
Filing Date: 2001-12-04
Classification: H02P

Abstract:
A synchronization controller including controllers of a master section and at least one slave section, each for controlling an electric motor, said synchronization controller serving to accurately synchronize a rotational frequency and a rotation phase of each said electric motor or a machine shaft driven by each said electric motor, each said slave section controller comprising:a master rotational frequency detector and a master phase counter for detecting simultaneously at all times a rotational frequency signal and a phase signal from an output of a rotary encoder coupled with the electric motor in the master section or from an output of a rotary encoder coupled with the machine shaft driven by said electric motor, said rotary encoder comprising an incremental encoder with a Z phase pulse, and said master phase counter operating to count the output pulses of said encoder and being cleared with said Z phase pulse;a slave rotational frequency detector and a slave phase counter for detecting simultaneously at all times a rotational frequency signal and a phase signal from an output of a rotary encoder coupled with the electric motor in the slave section or from an output of a rotary encoder coupled with the machine shaft driven by said electric motor, said rotary encoder comprising an incremental encoder with a Z phase pulse and said slave phase counter operating to count the output pulses of said encoder and being cleared with said Z phase pulse; anda phase deviation calculator for detecting a rotational phase deviation from the outputs of said master phase counter and said slave phase counter at all times, according to counted overflow pulses and the counted output pulses of said master phase counter and said slave phase counter, there being matched an origin of the electric motor in the master section and an origin of the electric motor in the slave section, or matched an origin of the machine shaft driven by the electric motor in the master section and an origin of the machine shaft driven by the electric motor in the slave section to achieve synchronous control.