Synchronous motor drive system and synchronous motor drive method
AssigneeSystem Homes Company, Ltd.
InventorHozo Yoshino
Life of this patent
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Abstract
The present disclosure is constructed on the prior art inverter architecture, a pulse code width modulation (PCWM). This is an open loop motor control system without sensing its rotor position. The present disclosure employs a closed loop method to track the optimum efficiency motor operating point directly. A bench load test is conducted to gather information for an AI type control, which includes both load angle vs. voltage command charts and power factor vs. voltage command charts, with load levels as parameters for certain frequency command ranges. This way, the optimum efficiency motor operating points are generated a priori. The AI type control is mechanized to track the optimum efficiency motor operating points.
Claims6
A synchronous motor drive system comprising:
- a synchronous motor;
- a power factor angle sensor for measuring a power factor angle of the synchronous motor;
- and
- a controller for generating a drive signal based on an input frequency command and the measured power factor angle, and supplying the drive signal to the synchronous motor,
- wherein the controller comprises a power factor angle control block for generating a voltage command based on the frequency command and the measured power factor angle to control the power factor angle, and
- wherein the power factor angle control block comprises:
- a voltage command generator for generating the voltage command;
- a target power factor angle table storing a target power factor angle to be targeted for a frequency and a voltage applied to the synchronous motor;
- a target power factor angle determination block for determining the target power factor angle based on the frequency command and the voltage command by referring to the target power factor angle table;
- and
- a power factor angle error calculator for calculating a power factor angle error between the target power factor angle and the measured power factor angle, wherein the voltage command generator adjusts the voltage command to be generated based on the power factor angle error.
Dependencies are inferred from the claim text.