Closed-loop Hall-type plasma actuator life monitoring system

Abstract

The closed-loop Hall-type plasma actuator life monitoring system disclosed in the present invention comprises a current detection circuit, an oscilloscope, a control system, a signal generator and a high-voltage power supply connected in sequence; the high-voltage power supply is also connected to a high-speed solid-state relay, and the high-speed solid-state relay is also connected to the control system. The system can monitor the current change of the plasma actuator in real time when it is working, avoid safety accidents caused by aging of the actuator and excessive temperature, and extend the service life of the plasma actuator.

Description

Technical Field

[0001] The invention belongs to the technical field of plasma actuator body control, and in particular relates to a closed-loop Hall type plasma actuator life monitoring system. Background Art

[0002] In recent years, active flow control technology has developed rapidly. Plasma flow control is a new type of active flow control technology based on plasma aerodynamic excitation, which has broad application prospects in improving the aerodynamic characteristics of aircraft / engines. The main device for realizing plasma flow control is the plasma actuator. The commonly used one is the dielectric barrier discharge (DBD) plasma actuator, which consists of upper and lower electrodes and an insulating dielectric layer in the middle. It has the advantages of small size, light weight, short response time, wide excitation frequency band, no mechanical moving parts, and can use tiny, local airflow disturbances to control large flow and global airflow. However, the disadvantage is that the service life of the plasma actuator is limited and it cannot be in a high-load state for a long time.

[0003] The key factor affecting the life of DBD plasma actuators is the high temperature resistance of the insulating dielectric layer. Due to the long-term discharge of DBD, the surface of the insulating dielectric layer will be severely etched by plasma, which will cause degradation, resulting in aging of the insulating layer and easy breakdown by the external electric field, which seriously shortens the service life of the actuator. Once the insulating dielectric layer of the plasma actuator is broken down, the equivalent resistance of the insulating dielectric layer suddenly decreases, the current in the loop system increases sharply, the transmission charge and discharge heat generated continue to increase, causing the temperature of the insulating layer to continue to rise, which is easy to cause safety hazards such as fire.

[0004] Currently, research on plasma actuator life detection is relatively scarce. Based on the above needs, the present invention proposes a closed-loop Hall-type plasma actuator life monitoring device, which can monitor the working status of the plasma actuator in real time and make intelligent control according to the working status in time, so as to avoid the plasma actuator working in a critical state for a long time, reduce the possibility of accident risk, and effectively extend the service life of the plasma actuator. Summary of the invention

[0005] The purpose of the present invention is to provide a closed-loop Hall-type plasma actuator life monitoring system, through which the current changes of the plasma actuator can be monitored in real time when the plasma actuator is working, to avoid safety accidents caused by actuator aging and excessive temperature, and to extend the service life of the plasma actuator.

[0006] The technical solution adopted by the present invention is a closed-loop Hall-type plasma actuator life monitoring system, which includes a current detection circuit, an oscilloscope, a control system, a signal generator and a high-voltage power supply connected in sequence; the high-voltage power supply is also connected to a high-speed solid-state relay, and the high-speed solid-state relay is also connected to the control system.

[0007] The present invention is also characterized in that

[0008] The current detection circuit includes a magnetic core and an operational amplifier. The magnetic core is a hollow ring magnetic core. A Hall element is arranged at the center of the magnetic core. A primary coil P is sleeved on the core of the magnetic core. C And the secondary coil S C The core of the magnetic core is also connected to resistors R1 and R2, which are also connected to the two input terminals of the operational amplifier respectively; the output terminal of the operational amplifier is connected to the secondary coil S C The first end of the secondary coil S C The second end is connected to the oscilloscope and the resistor R M Connection, resistor R M Ground.

[0009] The oscilloscope model is Tektronix DPO2024.

[0010] The signal generator model is Tektronix AFG3021.

[0011] The control system uses the Arduino UNO mainboard.

[0012] The beneficial effects of the present invention are:

[0013] (1) The system of the present invention fills the gap in the current plasma actuator experimental field and can effectively detect the working status of the current plasma actuator, thereby avoiding safety problems caused by aging of the insulation layer, increased current, and excessive temperature during the experiment.

[0014] (2) The current detection circuit adopted by the system of the present invention uses non-contact measurement, which has fast response speed and high measurement accuracy. When the primary and secondary magnetic fields reach equilibrium, the secondary compensation current is used to accurately reflect the primary current value.

[0015] (3) The system of the present invention can reflect the current changes of the plasma actuator during operation in real time, and use the control system to perform intelligent monitoring and feedback adjustment, thereby reducing the time the plasma actuator is in a critical state and slowing down the aging rate of the actuator.

[0016] (4) The system of the present invention has a simple structure, is easy to control, has a fast response speed, effectively avoids electromagnetic interference, and can be applied to the detection of most plasma actuators. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the closed-loop Hall-type plasma actuator life monitoring system of the present invention;

[0018] Figure 2 is a schematic diagram of the connection between the DBD exciter and the power supply in the system of the present invention;

[0019] Figure 3 It is a schematic diagram of a current detection circuit in the system of the present invention;

[0020] Figure 4 The present invention is a flowchart of the closed-loop Hall-type plasma actuator life monitoring system.

[0021] In the figure, 1. magnetic core, 2. Hall element, 3. operational amplifier, 4. DBD actuator, 5. actuator upper electrode, 6. actuator lower electrode, 7. actuator insulating dielectric layer, 8. plasma generation area, 9. direction of plasma induced flow, 10. current detection circuit, 11. signal generator, 12. oscilloscope, 13. high-speed solid-state relay, 14. control system, 15. high-voltage power supply, 16. primary coil P C , 17. Secondary coil S C . DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The present invention provides a closed-loop Hall-type plasma actuator life monitoring system, such as Figure 1-3 As shown, it includes a current detection circuit 10, an oscilloscope 12, a control system 14, a signal generator 11 and a high-voltage power supply 15 connected in sequence; the high-voltage power supply 15 is connected to the DBD exciter 4, and the DBD exciter 4 is connected to the current detection circuit 10; the high-voltage power supply 15 is also connected to a high-speed solid-state relay 13, and the high-speed solid-state relay 13 is also connected to the control system 14.

[0024] The current detection circuit 10 includes a magnetic core 1 and an operational amplifier. The magnetic core (1 is a hollow magnetic core in an annular shape; a Hall element 2 is arranged at the center of the magnetic core 1, and a primary coil P is sleeved on the core of the magnetic core 1. C 16 and secondary coil S C 17. Primary coil P C One end of 16 is connected to the upper electrode 5 of the exciter 4, and the primary coil P C The other end of 16 is connected to the lower electrode 6 of the exciter 4; the core of the magnetic core 1 is also connected to resistors R1 and R2, and the resistors R1 and R2 are also connected to the two input ends of the operational amplifier 3 respectively; the output end of the operational amplifier 3 is connected to the secondary coil S CThe first end of 17 is connected to the secondary coil S C The second end of 17 is connected to the oscilloscope 12 and the resistor R M Connection, resistor R M Ground; secondary coil S C The end 17 connected to the oscilloscope 12 is the M end.

[0025] According to the Hall effect principle, the current value is measured by the current detection circuit 10, and intelligent closed-loop control is performed through the control system 14 to achieve the effect of real-time monitoring of current changes.

[0026] The model of oscilloscope 12 is Tektronix DPO2024.

[0027] The model of the signal generator 11 is Tektronix AFG3021.

[0028] The control system 14 uses an Arduino UNO mainboard.

[0029] The DBD exciter 4 uses a conventional DBD, including an upper electrode 5, an insulating dielectric layer 7 and a lower electrode 6 arranged from top to bottom. The distance between the upper and lower electrodes is 0.01mm-0.3mm, the thickness of the insulating dielectric layer 7 is 0.01mm-0.1mm, and the material of the insulating dielectric layer 7 is polytetrafluoroethylene with a dielectric constant of 2.

[0030] The upper electrode 5 of the DBD actuator 4 is connected to the output end of the high-voltage power supply 15, the lower electrode 6 is connected to the ground, and the output end of the signal generator 11 is connected to the signal input end of the high-voltage power supply 15. When the supplied voltage is low, the current is small; as the voltage gradually increases, the current also increases rapidly, and plasma is gradually generated. Long-term discharge will cause the insulating dielectric layer to be broken down. In the figure, 8 is the plasma formation area, and 9 is the direction of induced flow.

[0031] The current detection circuit 10 is as follows Figure 2 As shown, I N is the primary current, I M is the secondary current, resistors R1, R2, and R M The resistance values ​​are 10k, 10k, and 100k respectively. The working principle of the current detection circuit 10 is that the primary coil P C The magnetic field generated by the secondary coil S C The magnetic field generated by the current is compensated to keep the Hall element 2 in the state of detecting zero magnetic flux. When the magnetic fields generated by the primary and secondary compensation currents reach equilibrium in the magnetic core 1, the primary current I can be calculated by the formula N , thus realizing non-contact measurement of DBD plasma actuator current.

[0032] N×I N=n×I M (1)

[0033] Where: N is the number of turns of the primary coil, n is the number of turns of the secondary coil, I N is the primary current, I M is the secondary side compensation current.

[0034] In the current detection circuit, the primary coil P C and the secondary coil S C High voltage resistant wires are selected to be wound around the two sides of the magnetic core 1. The magnetic core 1 is a hollow annular magnetic core. The Hall element 2 can be made of a cylindrical metal conductor and placed through the middle of the magnetic core. The number of coil windings can be obtained according to formula (1). The primary coil P C The two ends of 16 are connected to the upper electrode 5 and the lower electrode 6 of the DBD exciter 4 respectively, and the secondary coil S C The M end of 17 is connected to the input end of the oscilloscope 12, and the other end is grounded. At this time, the current between the upper and lower electrodes of the exciter flows through the magnetic field generated by the conductor, and the secondary current I M The magnetic field compensation generated by the secondary coil is generated. When the magnetic fields of the primary and secondary sides reach equilibrium, the secondary current I M Can accurately reflect the primary current I N (i.e., the current value between the upper and lower electrodes of DBD), resistors R1 and R2 are two 10k resistors connected to the magnetic core 1, and the other side of the resistor is connected to the two input terminals of the operational amplifier 3. The output of the operational amplifier is connected to the secondary coil S C 17 One side connected, R M A 100k resistor is connected in parallel to the secondary coil S C Measuring end M.

[0035] Figure 4 This is a work flow chart of the closed-loop Hall plasma actuator life monitoring system. Since the commonly used parameter in the experiment is the voltage value, the oscilloscope 12 collects the current value of the M terminal of the current detection circuit 10, and the control system 14 transmits data with the oscilloscope 12 through the I / O port and converts the current value into a voltage value according to Ohm's law. Research shows that the discharge starting voltage of the DBD exciter 14 is about 7kV, and the breakdown voltage of the insulating dielectric layer 7 is about 9kV; the duty cycle is set to 50% during normal discharge, so when its voltage value is less than 7kV, the control system 14 controls the signal generator 11 to change the parameters to increase the voltage of the DBD exciter 14 to make it enter a discharge state; when its voltage value is between 7kV and 8kV, the DBD exciter is in a stable discharge state; when its voltage value is between 8kV and 9kV, in order to slow down the breakdown speed of the DBD exciter, the control system 14 controls the signal generator 11 to reduce the duty cycle to 25%, and when the voltage value is greater than 9kV, the insulating dielectric layer 7 is in a critical state and faces the risk of being broken down. At this time, the control system 15 directly controls the high-voltage solid-state relay 13 to cut off the high-voltage power supply.

[0036] The system of the present invention has the following advantages: first, it fills the gap in the current plasma exciter experimental field, can effectively detect the current working state of the plasma exciter, and avoid safety problems caused by excessive current and excessive temperature during the experiment; second, the current detection circuit used in the present invention has fast response speed, high measurement accuracy, and the use of non-contact measurement can effectively avoid electromagnetic interference; third, the system structure of the present invention is flexible and simple, easy to control, and can be applied to most plasma flow control systems; fourth, the system of the present invention adopts the control system minimum control system to intelligently monitor the DBD exciter; fifth, the device of the present invention has low cost, good performance and high reliability; sixth, the system of the present invention can improve the safety of the experiment, and at the same time adopt different control strategies according to different working states, effectively save energy and improve economy.

Claims

1. A closed-loop Hall-type plasma actuator life monitoring system, characterized in that: The invention comprises a current detection circuit (10), an oscilloscope (12), a control system (14), a signal generator (11) and a high-voltage power supply (15) which are connected in sequence; the high-voltage power supply (15) is also connected to a high-speed solid-state relay (13), and the high-speed solid-state relay (13) is also connected to the control system (14); The current detection circuit (10) comprises a magnetic core (1) and an operational amplifier (3); the magnetic core (1) is a ring-shaped hollow magnetic core; a Hall element (2) is arranged at the center of the magnetic core (1); a primary coil P is sleeved on the core of the magnetic core (1); C (16) and secondary coil S C (17); the core of the magnetic core (1) is also connected to a resistor R1 and a resistor R2, and the resistor R1 and the resistor R2 are also respectively connected to the two input ends of the operational amplifier (3); the output end of the operational amplifier (3) is connected to the secondary coil S C The first end of (17) is connected to the secondary coil S C The second end of (17) is connected to the oscilloscope (12) and the resistor R M Connection, resistor R M Grounding; When the voltage value of the DBD exciter is less than 7 kV, the control system (14) controls the signal generator (11) to change the parameters to increase the voltage of the DBD exciter so that it enters a discharge state; when the voltage value of the DBD exciter is between 7 kV and 8 kV, the DBD exciter is in a stable discharge state; when the voltage value of the DBD exciter is between 8 kV and 9 kV, in order to slow down the breakdown speed of the DBD exciter, the control system (14) controls the signal generator (11) to reduce the duty cycle to 25%; when the voltage value of the DBD exciter is greater than 9 kV, the exciter insulating dielectric layer (7) is in a critical state, at which time the control system (14) directly controls the high-voltage solid-state relay (13) to cut off the high-voltage power supply.

2. The closed-loop Hall-type plasma actuator life monitoring system according to claim 1, characterized in that: The model of the oscilloscope (12) is Tektronix DPO2024.

3. The closed-loop Hall-type plasma actuator life monitoring system according to claim 1, characterized in that: The model of the signal generator (11) is Tektronix AFG3021.

4. The closed-loop Hall-type plasma actuator life monitoring system according to claim 1, characterized in that: The control system (14) uses an Arduino UNO mainboard.

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