Motor Drive Power Conversion Unit Time-Sharing Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor drive devices with power storage units suffer from low operating rates of converters and inverters, leading to inefficiencies and increased costs due to the large space and cost occupation of these units, which are not effectively utilized when detached from the AC power supply or connected to the power storage unit.
Innovation Solution
A motor drive device with a power conversion unit that selectively executes converter and inverter operations, a power storage unit for storing and supplying DC power, and a control unit that manages the switching between AC power supply and motor connection to optimize energy usage, allowing the power conversion unit to operate as a single bridge circuit in a time-sharing manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a power storage unit is provided on the DC link to reduce power peak, then the capacity of power supply facility can be reduced, but the converter and inverter have low operating rates and are not effectively utilized
Solution Approach 1:
The patent makes the power conversion unit perform multiple functions: it operates as a converter during charging periods and as an inverter during discharging periods. This multi-functionality allows the same hardware to serve different purposes at different times, increasing its utilization rate while still achieving power peak reduction through the power storage unit.
Solution Approach 2:
The patent implements periodic charging and discharging operations of the power storage unit. The converter charges the power storage unit during low-demand periods, and the inverter discharges it during peak periods. This periodic action ensures continuous operation of the power conversion unit, maintaining high operating rates while achieving power peak reduction.
2Reliability
If the converter and inverter are provided as separate units for power conversion, then the reliability of power conversion is improved, but the device complexity and space occupation increase
Solution Approach 1:
The patent combines the converter and inverter functions into a single power conversion unit that can operate in different modes. By merging these functions and using a common bridge circuit for both converting AC to DC and converting DC to AC, the system reduces the number of separate units while maintaining power conversion reliability through controlled operational phases.
3Productivity
If the power conversion unit operates continuously to maintain high operating rate, then productivity is improved, but the power storage unit may not have sufficient time to charge or discharge completely
Solution Approach 1:
The patent performs preliminary charging of the power storage unit during low-demand periods before peak power demand occurs. By charging in advance when there is no immediate motor driving demand, the system ensures the power storage unit is ready to provide rapid discharge during peaks, maintaining both continuous operation and sufficient charge/discharge duration.
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 configuration enhances the operating rate of the power conversion unit, reduces the number of parts, and decreases the capacity of the power supply facility, resulting in a smaller, lower-cost motor drive device that effectively manages power peaks and reduces AC current requirements during storage and motor operation.
Implementation Method 1
a power conversion unit (11) including an AC terminal (31) and a DC terminal (32), and configured to selectively execute a converter operation of converting AC power input through the AC terminal (31) into DC power and outputting the DC power through the DC terminal (32), and an inverter operation of converting DC power input through the DC terminal (32) into AC power for motor driving and outputting the AC power through the AC terminal (31)
Implementation Method 2
a power storage unit (12) electrically connected through the DC terminal (32) on the power conversion unit (11), and configured to store DC power output from the power conversion unit (11) and supply DC power to the power conversion unit (11)
Data Source
AI summary
A motor drive device includes a power conversion unit configured to selectively execute a converter operation of converting AC power into DC power, and an inverter operation of converting DC power into AC power for motor driving, a power storage unit configured to store DC power output from the power conversion unit and also supply DC power to the power conversion unit, a switching unit configured to switch between an AC power supply and a motor a connection destination of the power conversion unit, and a control unit configured to control the switching unit to have the power conversion unit connected to the AC power supply and control the power conversion unit to have the converter operation executed, and configured to control the switching unit to have the power conversion unit connected to the motor and control the power conversion unit to have the inverter operation executed.