DC Power Supply Phase Synchronization for Plasma Arc Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
DC power supply devices for plasma generators face issues with voltage fluctuations and delays in restarting due to misalignment of pulse control signals during restarts, leading to unstable operations and potential damage to electrodes and substrates.
Innovation Solution
The DC power supply device synchronizes the phase of the pulse control signal upon restarting with the phase at suspension, using a current source chopper and multiphase inverter to hold circulating current and gate signal states, reducing voltage fluctuations and delays in resuming DC power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the DC power supply device stops for a predetermined period after detecting arc discharge, then arc discharge is suppressed, but maintaining glow discharge becomes difficult and operational stability deteriorates
Solution Approach 1:
The patent applies periodic action by implementing a timing control mechanism that resumes power supply after a predetermined period following arc discharge detection. This controlled periodic resumption allows the system to suppress arc discharge while maintaining glow discharge stability, avoiding both continuous arcing and prolonged interruption that would disrupt plasma generation.
Solution Approach 2:
The patent changes the parameter of power supply timing by introducing a predetermined time period delay after arc discharge detection. This parameter modification enables the system to balance arc suppression with glow discharge maintenance, optimizing both reliability and operational stability through controlled temporal separation between arc events and power resumption.
2Productivity
If the inverter is restarted without phase synchronization, then power supply is quickly restored, but output voltage fluctuates and operational stability deteriorates
Solution Approach 1:
The patent implements feedback by detecting the phase of the pulse control signal at the time of suspension and using this information to control the restart timing of the inverter. This feedback mechanism ensures phase synchronization upon restart, maintaining output voltage stability while enabling quick power supply restoration without harmful voltage fluctuations.
Solution Approach 2:
The patent applies preliminary action by storing the phase information of the pulse control signal before suspension occurs. This preliminary recording of phase data enables the system to synchronize the inverter restart with the original phase, ensuring stable output voltage when power supply is restored, thus maintaining both productivity and reliability.
3Reliability
If a large capacitor is connected to the output, then output voltage is maintained, but excessive discharge current flows during arc occurrence and arcing time is elongated
Solution Approach 1:
The patent introduces an intermediary mechanism by using the current source chopper circuit between the power supply and the load. This intermediary controls the current flow to the inverter and load, preventing excessive discharge current during arc occurrence while maintaining output voltage through controlled current supply, thus resolving the contradiction between voltage maintenance and harmful current suppression.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A phase of the pulse control signal upon restarting is synchronized with the phase of the pulse control signal upon suspending, thereby suppressing fluctuations of output voltage in each phase of the inverter upon restarting and further suppressing fluctuations of voltage supplied to the load. Upon supplying DC power to a plasma generator, when arc discharge occurs in the plasma generator, supplying of the DC power is suspended to reduce damage on the electrodes and substrate, and further upon extinguishing of the arc discharge, supplying of the DC power is restarted. In suspending and resuming the DC output, the current flowing in the chopper upon suspending is held in the form of circulating current, and upon restarting the inverter, this circulating current is supplied to the load. Accordingly, it is possible to reduce a delay in supplying the DC power to the load, upon resuming the DC output.