Power Converter Control Circuit Abnormality Handling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control circuits for electric power converters face issues with rotor speed-induced line-to-line voltage increases during shutdown, leading to regeneration and potential reliability degradation or failure in DC power sources and components.
Innovation Solution
The proposed control circuit implements an all-phase short circuit control mechanism that prevents regeneration by forming a closed circuit with turned-on switches and phase windings, rather than diodes and phase windings, to manage induced currents and prevent DC voltage rises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If switches are turned off to stop abnormal current flow, then harmful current is reduced, but line-to-line voltage increases causing torque spikes
Solution Approach 1:
The patent modifies switching parameters based on the specific abnormality detected, changing from uniform switch-off to selective switch control. By maintaining appropriate switch states in non-abnormal paths, it prevents the line-to-line voltage increases that cause torque spikes while still stopping the abnormal current flow through the affected paths.
2Device complexity
If uniform switch-off control is used for all abnormalities, then control simplicity is maintained, but system performance degrades due to regeneration
Solution Approach 1:
The patent implements dynamic switch control where the switching state of each switch pair is adjusted based on the specific abnormality detected. The control transitions from a static uniform off-state to a dynamic state where switches are selectively controlled based on real-time abnormality information, thereby preventing regeneration while maintaining manageable control complexity through systematic decision logic.
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 prevents DC voltage increases and torque spikes, enhancing the reliability and safety of electric power converters by managing induced currents within the control circuit.
Implementation Method 1
a line-to-line voltage between the phase windings of the rotating electric machine when a counterelectromotive force is generated in the phase windings
Implementation Method 2
Each of the upper-arm and lower-arm switches has a diode electrically connected in antiparallel thereto
Data Source
AI summary
A control circuit for an electric power converter includes an abnormality determiner, a voltage determiner and an abnormality-handling controller. The abnormality determiner determines whether an abnormality has occurred in at least one of the electric power converter and a multi-phase rotating electric machine. The voltage determiner determines whether a line-to-line voltage between phase windings of the rotating electric machine is higher than a voltage of a DC power source. The abnormality-handling controller performs, when it is determined by the abnormality determiner that an abnormality has occurred and it is determined by the voltage determiner that the line-to-line voltage is higher than the voltage of the DC power source, an all-phase short circuit control of turning on all of switches of one of an upper-arm switch group and a lower-arm switch group and turning off all of switches of the other of the upper-arm switch group and the lower-arm switch group.