Power supply auxiliary modulation device for improving signal-to-noise ratio of ionic current

Abstract

The invention relates to a power supply auxiliary modulation device for improving the signal-to-noise ratio of ionic current. The device comprises a primary coil loop consisting of a direct-current power supply, a primary coil of an ignition coil and an IGBT (Insulated Gate Bipolar Transistor), and a secondary coil loop consisting of a secondary coil of the ignition coil, a rectifying circuit anda spark plug in sequence, wherein a grid electrode of the IGBT is connected and disconnected through an ignition module of the ECU and controls frequency, a source electrode of the IGBT is connected with a direct-current power supply, a drain electrode of the IGBT is grounded, the rectifying circuit comprises a first voltage stabilizing diode and a switch which are connected in parallel, and the spark plug is represented by a second capacitor and a second resistor which are connected in parallel. Compared with the prior art, the device has the advantages of improving the signal-to-noise ratioof ionic current signal, avoiding the problem of inaccurate detection caused by aging, corrosion and carbon deposition of the spark plug, being low in cost and the like.

Description

technical field [0001] The invention relates to the technical field of internal combustion engines, in particular to a power auxiliary modulation device for improving the signal-to-noise ratio of ion currents. Background technique [0002] In future high-efficiency, clean and zero-emission engines with high compression ratio / lean combustion as the main technology, the feedback control of combustion will become a key technical bottleneck. In recent years, the world's major engine OEMs have paid more attention to the direct detection of engine combustion, especially the detection of ion current in the cylinder. Today, after more than 100 years of development of engine technology, it has become the solution to the development trend of ultra-efficient and near-zero emissions. The inevitable result and one of the core demands, the flame ion detection method can provide low-cost and real-time feedback on the combustion state, and has shown the potential for large-scale application...

AI Technical Summary

Problems solved by technology

In recent years, the world's major engine OEMs have paid more attention to the direct detection of engine combustion, especially the detection of ion current in the cylinder. Today, after more than 100 years of development of engine technology, it has become the solution to the development trend of ultra-efficient and near-zero emissions. The inevitable result and one of the core demands, the flame ion detection method can provide low-cost and real-time feedback on the combustion state, and has shown the potential for large-scale application in recent years. However, in high compression ratio engines, the ion current signal has a signal-to-noise ratio. Low, the detection results are affected by the position of the probe, which has a "local" problem. In addition, with the long-term operation of the engine, the spark plug will have problems such as aging, corrosion, and carbon deposition, which will significantly change its resistance characteristics and affect the ion current. detection

[0003] In recent years, researchers have analyzed the motion of flame plasma in the electric field at different macro-micro scales through theoretical research on the coupling of electric field-flame ion formation mechanism-reaction flow field, and obtained a key conclusion, that is, the flame The electrons inside are attracted by the cations, and are mainly adsorbed near the cations in the form of "bipolar diffusion", so they cannot effectively diffuse out of the flame front. This mechanism seriously affects the effectiveness of the ion current detection probe on the local ion current signal. measurement, which makes the ion current detection method localized, and even loses the detection ability under some conditions, which is the core of the limitations of the current ion current detection system

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