Synchronous motor drive device, air-sending device and air-conditioning device
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Solution Overview
Problem
Parallel drive systems for brushless synchronous motors face instability issues, particularly at low speed rotation, leading to pulsating currents and speed instability, which restricts the drive range and increases costs due to the need for multiple power sources.
Innovation Solution
A synchronous motor drive device that includes a power converter and a controller to selectively connect and disconnect power to multiple motors, allowing for stable operation by determining the number of motors and drive speed, thereby enabling optional motor operation at desired speeds without requiring all motors to run at low speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple brushless synchronous motors are connected in parallel to one power source, then the number of power sources is reduced and cost is suppressed, but the system becomes unstable at low speed rotation with pulsating currents and speed fluctuations
Solution Approach 1:
The controller segments the control of multiple motors by individually managing the switching timing for each motor connected in parallel. This allows independent control of power supply timing to each motor, preventing mutual interference and instability while maintaining a single power source configuration.
Solution Approach 2:
The system dynamically adjusts the switching timing of each motor based on their individual operational requirements. The controller varies the power supply timing adaptively, enabling stable operation of multiple motors in parallel across different speed ranges, particularly improving low-speed stability.
2Device complexity
If brushless synchronous motors are driven in parallel, then cost is reduced by using one power source, but the drive range is restricted due to stability issues
Solution Approach 1:
The controller dynamically adjusts switching timing based on motor speed and load conditions, enabling stable operation across a wide drive range from low to high speeds. This dynamic control eliminates the need to restrict the drive range while maintaining cost efficiency through a single power source.
Solution Approach 2:
The system changes the switching timing parameters for each motor based on operational conditions. By adjusting these parameters dynamically, the system maintains stability across the entire drive range, from low-speed rotation to high-speed operation, without restricting versatility.
3Device complexity
If all motors are operated in parallel, then power distribution is simplified, but noise and energy loss increase and performance optimization is limited
Solution Approach 1:
The controller segments the power distribution control by independently managing switching timing for each motor. This allows selective operation where only necessary motors are activated, reducing overall energy consumption and noise while maintaining simplified power distribution architecture.
Solution Approach 2:
The system dynamically determines which motors to operate based on load requirements, switching timing, and operational conditions. This dynamic selection optimizes energy efficiency and noise reduction while maintaining the simplicity of a single power source distribution system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution stabilizes motor operation across various speeds, reduces component costs by allowing selective motor operation, and optimizes performance in air-conditioning applications by ensuring required air volume and minimizing noise and loss.
Implementation Method 1
a power converter that converts power from a power source to supply the power to the plurality of synchronous motors
Implementation Method 2
a first switch device that electrically connects or disconnects the power converter and each of the plurality of synchronous motors
Implementation Method 3
brushless synchronous motors have been configured to be contactless
Data Source
AI summary
A synchronous motor drive device drives a plurality of synchronous motors, and includes a power converter that converts power to supply power to the plurality of synchronous motors, a first switch device that electrically connects or disconnects between the power converter and each of the plurality of synchronous motors, and a controller that, based on a higher order command, performs stability judgment processing of the plurality of synchronous motors, determines the number of synchronous motors to be driven and a drive speed from among the plurality of synchronous motors, selects a synchronous motor corresponding to the number of the synchronous motors from among the plurality of synchronous motors, controls the first switch device corresponding to the selected synchronous motor to electrically connect the power converter to the synchronous motor and to supply the power, and instructs, to the power converter, the drive speed of the synchronous motor to be driven.