DC Bus Voltage Regulation via Rectifier and Inverter Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power conversion systems face challenges in effectively regulating DC bus voltage, particularly when the voltage exceeds certain thresholds, leading to overvoltage conditions due to limited regenerative capabilities of switching rectifiers.
Innovation Solution
A processor-controlled system that operates a switching rectifier in different modes based on DC bus voltage thresholds, using rectifier switching control for motoring and regenerative operations, and inverter acceleration/deceleration control when the rectifier's regenerative capabilities are exhausted, to prevent overvoltage by supplementing with inverter regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If switching rectifier regenerative capability is used to regulate DC bus voltage, then voltage regulation is achieved within normal range, but overvoltage protection is insufficient when voltage exceeds threshold
Solution Approach 1:
The inverter is designed to perform dual functions: normal motor control and DC bus overvoltage protection. By enabling the inverter to function as a dynamic brake through regenerative braking, the system eliminates the need for separate protection circuits while enhancing overall system reliability and adaptability
2Reliability
If DC bus capacitance is increased to absorb regenerative energy, then overvoltage protection is improved, but system complexity and cost increase
Solution Approach 1:
The system uses its own inverter and motor to absorb regenerative energy through regenerative braking, converting kinetic energy back into electrical energy. This self-service approach eliminates the need for external energy dissipation circuits or large DC bus capacitors, reducing system complexity while maintaining effective overvoltage protection
3Reliability
If energy dissipation circuit is added to handle regenerative energy, then overvoltage protection is achieved, but energy efficiency decreases
Solution Approach 1:
The system converts the harmful regenerative energy that causes overvoltage into a beneficial resource by using it for regenerative braking. The energy that would otherwise be wasted or dissipated is instead captured and reused to drive the motor, transforming an environmental harm into an energy-saving benefit while providing overvoltage protection
Data Source
AI summary
Power converters, controllers, methods and non-transitory computer readable mediums are presented, in which a processor operates a switching rectifier in a first mode to regulate a DC bus voltage signal using rectifier switching control for motoring rectifier operation when the measured DC bus voltage value is less than or equal to a first threshold value, operates the switching rectifier in a second mode to regulate the DC bus voltage signal using rectifier switching control for regenerative rectifier operation when the measured DC bus voltage value is greater than the first threshold value and less than or equal to a higher second threshold value, and operates an inverter in a third mode to regulate the DC bus voltage signal using inverter acceleration/deceleration control when the measured DC bus voltage value is greater than the second threshold value.