EMC Control for Pulsed High Voltage Plasma Source
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Solution Overview
Problem
Existing devices for generating non-thermal plasma used in treating living tissue face challenges in treating larger areas, controlling plasma properties, and adapting to irregularly shaped surfaces, while also experiencing high voltage oscillations that cause electromagnetic interference.
Innovation Solution
A high voltage source coupled to an electrode arrangement with a transformer device, power capacitor, and controllable conductors to manage pulsed primary current and short resonating currents in the primary inductor, reducing electromagnetic oscillations and interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an oscillating high voltage circuit is used to generate pulsed plasma, then plasma generation is achieved, but electromagnetic interference and high voltage oscillations are produced
Solution Approach 1:
The patent applies periodic pulsed operation with a duty cycle of 1-50% to generate plasma only during specific intervals. The high voltage is applied in pulses rather than continuously, which allows plasma generation while minimizing electromagnetic interference during the off periods. This periodic action resolves the contradiction by confining plasma power delivery to specific time windows.
Solution Approach 2:
The patent converts the harmful resonant oscillations into a beneficial control mechanism by intentionally designing an oscillating circuit that resonates at a known frequency. The controller detects these oscillations and uses them to synchronize the pulsing operation, transforming the harmful electromagnetic interference into a timing reference for controlled plasma generation.
2Power
If high voltage is applied to an open mesh electrode to generate plasma, then plasma is produced, but the mesh acts as a radio antenna emitting electromagnetic radiation
Solution Approach 1:
By applying high voltage in short pulses with low duty cycle (1-50%), the patent minimizes the time the mesh electrode is energized, thereby reducing its antenna effect. The plasma is generated only during the pulse duration, and the electrode remains inactive during off periods, significantly reducing electromagnetic radiation.
Solution Approach 2:
The patent implements preliminary damping of oscillations by designing the circuit with specific resistance values and using a controller that detects and dampens resonant oscillations before they can radiate significantly. This preliminary anti-action prevents the mesh from acting as an efficient antenna.
3Power
If pulsed operation is used to control plasma power, then plasma power can be adjusted, but electromagnetic compatibility problems arise
Solution Approach 1:
The patent incorporates a controller that detects oscillations in the circuit and uses this feedback to adjust the pulsing operation. The controller monitors the resonant frequency and damping characteristics, then adapts the pulse timing and duration to maintain electromagnetic compatibility while preserving plasma power control capability.
Solution Approach 2:
The patent changes multiple parameters including pulse duration, duty cycle (1-50%), frequency, and circuit resistance to optimize both plasma power control and electromagnetic compatibility. By adjusting these parameters, the system achieves plasma generation with minimized electromagnetic interference.
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 effectively reduces electromagnetic interference and allows for controlled plasma treatment of irregularly shaped surfaces, enhancing the effectiveness and safety of plasma devices for medical and dermatological applications.
Implementation Method 1
a high voltage transformer device including a primary and secondary inductor coupled via a magnetic circuit
Implementation Method 2
to provide a pulsed primary current in the primary inductor resonating with the capacitor when the first controllable conductor is switched in a conducting on-state
Implementation Method 3
a high voltage source to be coupled to an electrode arrangement for a dielectric barrier discharge plasma treatment
Data Source
AI summary
The invention relates to a high voltage source to be coupled to an electrode arrangement for a dielectric barrier discharge plasma treatment. It has a high voltage transformer device including a primary and secondary inductor coupled via a magnetic circuit. A feed circuit including a power capacitor, the power capacitor coupled with the primary inductor and a first controllable conductor in series. A controller is arranged to intermittent switching of the first controllable conductor in on- and off-states; and a second controllable conductor is coupled in parallel to the primary windings; the controller arranged to switch the second controllable conductor to a conducting on-state when the first controllable conductor is in an on-state to short the resonating current in the primary inductor.