Power Converter Control Device for Motor Efficiency
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Solution Overview
Problem
Existing direct power converter systems face inefficiencies in driving motors, particularly in achieving high-load operations while managing motor current and efficiency across varying rotational speeds.
Innovation Solution
A power converter control device that adjusts the operation of a discharge switch and capacitor in series with a boost circuit, controlling time periods to optimize DC voltage input to an inverter, ensuring higher DC voltage during high-speed operations and reduced voltage during low-speed operations, thereby maximizing motor output and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the discharge switch is kept conducting to maintain high DC voltage for high-speed motor operation, then motor speed and load capacity are improved, but motor current increases excessively causing efficiency degradation
Solution Approach 1:
The patent applies dynamics by making the discharge switch control strategy adaptive based on motor operating conditions. The control device dynamically adjusts the discharge switch between conducting and non-conducting states according to detected motor speed and current levels, enabling the system to optimize between speed performance and efficiency across different operating ranges rather than maintaining a fixed state
Solution Approach 2:
The patent changes the operational parameters of the discharge switch based on motor operating conditions. When motor speed exceeds a threshold or current becomes excessive, the control device transitions the discharge switch from a conducting state (providing high DC voltage for speed) to a non-conducting state (reducing current for efficiency), thereby adjusting system parameters to match operational requirements
2Adaptability or versatility
If the discharge switch is switched frequently to optimize DC voltage for varying motor speeds, then motor performance across speed ranges is improved, but system complexity and control difficulty increase
Solution Approach 1:
The patent employs parameter changes by adjusting the discharge switch state based on motor speed thresholds. The control device monitors motor speed and current parameters, and transitions the discharge switch between conducting and non-conducting states when predefined thresholds are exceeded, enabling adaptive performance optimization across different speed ranges through parameter-based control logic
Solution Approach 2:
The patent implements feedback control by continuously detecting motor speed and current levels, then using this information to control the discharge switch state. The control device receives feedback from the motor operating conditions and adjusts the discharge switch accordingly, creating a closed-loop system that balances performance and efficiency based on real-time motor status
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
The solution enables high-load motor operation at high speeds while suppressing current increase and improving efficiency at low speeds by dynamically controlling the DC voltage, reducing losses in the boost circuit and enhancing overall motor performance.
Implementation Method 1
the rectifying circuit full-wave rectifying a single-phase AC voltage to a rectified voltage
Implementation Method 2
the discharge switch and the capacitor being connected in series to each other between the first and second DC power supply lines
Implementation Method 3
the boost circuit boosting the rectified voltage to charge the capacitor
Data Source
AI summary
A discharge switch and a capacitor are connected in series between first and second DC power supply lines. A boost circuit boosts a rectified voltage to charge the capacitor. An inverter receives the rectified voltage as a DC voltage when the discharge switch is not conducting, receives a voltage across the capacitor as the DC voltage when the discharge switch is conducting, converts the DC voltage into an AC voltage, and outputs it to a motor. A switch control unit maintains the discharge switch not conducting over a first time period, and switches the discharge switch between conducting and not conducting in a second time period. A charge and discharge time period setting unit sets the first time period when a rotational speed of the motor is higher than a speed threshold shorter than the first time period when the rotational speed is lower than the speed threshold.