Power Converter Control Device for Vibration Suppression
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Solution Overview
Problem
Existing power converter systems struggle to simultaneously suppress vibrations and power fluctuations in rotary electric machine driving systems, leading to adverse effects on system stability and energy efficiency.
Innovation Solution
A control device is introduced that includes an inverter control unit, a converter control unit, a vibration suppression control unit, and an output compensation control unit, which calculates and applies correction values to stabilize the system by canceling axial vibrations and compensating for power fluctuations, using a capacitor to manage DC power and an inverter to convert AC power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If vibration suppression control is applied to cancel axial vibration components, then vibration of the driving system is suppressed, but power supplied from or regenerated to the AC power supply fluctuates
Solution Approach 1:
The patent introduces a capacitor as an intermediary energy storage device between the converter and inverter. The capacitor absorbs power fluctuations caused by vibration suppression control, decoupling the vibration cancellation function from direct impact on AC power supply/regeneration stability.
Solution Approach 2:
The patent replaces direct mechanical torque fluctuation control with electrical control methods. Instead of mechanically adjusting torque to suppress vibration, the system uses electrical control signals to achieve vibration suppression while maintaining stable power flow through the capacitor buffer.
2Object-affected harmful factors
If torque command compensation is calculated to suppress vibration, then axial vibration is reduced, but torque of the rotary electric machine fluctuates
Solution Approach 1:
The patent segments the torque control into separate components: base torque command for power transmission and compensation torque command for vibration suppression. This segmentation allows independent optimization of each function without mutual interference.
Solution Approach 2:
The patent changes the control parameter from direct torque control to frequency-based vibration suppression control. By detecting vibration frequency and applying compensatory control at that specific frequency, the system suppresses vibration while maintaining overall torque stability through the capacitor's energy buffering capability.
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 effectively suppresses both vibrations and power fluctuations, ensuring stable operation and efficient energy transfer in rotary electric machine driving systems, enhancing system reliability and power quality.
Implementation Method 1
The power converter converts AC power of the power supply into DC power using a converter
Implementation Method 2
The power converter converts AC power of the power supply into DC power using a converter, and converts the DC power into AC power using an inverter
Implementation Method 3
a capacitor that is installed between the converter and the inverter and is charged with and discharges the DC power
Implementation Method 4
a vibration suppression control unit that calculates a vibration correction value for canceling an axial vibration component clue to a vibration frequency of a transmission system including the rotary electric machine
Implementation Method 5
an output compensation control unit that calculates a fluctuation correction value for suppressing AC power of the power supply fluctuated by the vibration suppression control unit
Data Source
AI summary
A control device of a power converter controls a system including a converter that converts alternating current (AC) power of a power supply into direct current (DC) power, an inverter that converts the DC power into AC power, a capacitor that is charged with and discharges the DC power, and a rotary electric machine that is driven by the AC power supplied from the inverter or regenerates the AC power to the power supply, the control device including: a vibration suppression control unit that outputs a torque current command correction value for canceling an axial vibration component due to a vibration frequency of a transmission system including the rotary electric machine and an output compensation control unit that outputs a correction value for suppressing AC power of the power supply fluctuated by the vibration suppression control unit to a voltage control unit of the converter.