A real-time detection system and method for high-power arc heater DC power thyristor

Abstract

A kind of high-power arc heater DC power thyristor real-time detection system and method, by including thyristor, signal sampling unit, rectifier filter unit, signal analog-digital conversion unit, digital signal processing unit, DC power protection subsystem, power supply unit, find out the shortcomings of using fast fuse protection by using the principle of fast fuse protection.By using digital signal processing technology, the voltage value of the two ends of thyristor is detected in real time, so as to realize the judgment of the good or bad of thyristor.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of high-power arc heater DC power thyristor real-time detection system and method, belong to power electronics field. BACKGROUND

[0002] With the continuous development of space technology in our country, spacecraft material research becomes one of the key technologies. Spacecraft in the process of crossing atmosphere, high-speed friction can make its surface material withstand high temperature, high pressure and other external environment. In order to prevent aerodynamic heating from causing damage even destroy spacecraft, cause serious accidents. Arc heating plasma wind tunnel, simply called arc wind tunnel as an effective means of spacecraft atmospheric environment simulation experiment, mainly for spacecraft reentry vehicle aerodynamic environment simulation experiment provides high temperature, high pressure state, it uses the high temperature of arc to heat gas, can provide spacecraft heat-resistant material screening, ablation and ablation shape change experiment, thereby greatly improving the safety and reliability of spaceflight.

[0003] Arc heater system as the most important part of arc wind tunnel system, power is in 10MW~50MW order of magnitude, mainly includes DC power supply system and arc heater body two parts. High heat content and stable arc combustion, directly determines the experimental ability and experimental quality of arc wind tunnel.

[0004] High-voltage high-power DC power supply provides energy for arc heater, its power can reach 63MW order of magnitude, it can provide the required voltage and current of heater according to the characteristics of heater. High voltage and high power at the same time meet is a test of power supply itself. As the core device of power conversion, how to effectively detect and protect thyristor becomes an important research direction of power electronics, and there is still a lack of complete detection technology in the prior art. SUMMARY

[0005] The technical problem solved by the present application is that there is still a lack of effective detection and protection of thyristor means in the prior art. The present application provides a high-power arc heater DC power thyristor real-time detection system and method.

[0006] The present application solves the above technical problems by the following technical solutions:

[0007] A kind of high-power arc heater DC power thyristor real-time detection system, including thyristor, signal sampling unit, rectifier filter unit, signal analog-digital conversion unit, digital signal processing unit, DC power protection subsystem, power supply unit, wherein:

[0008] The thyristor is connected with the input end of the signal acquisition unit, the output end of the signal acquisition unit is connected with the input end of the rectification filtering unit, the output end of the rectification filtering unit is connected with the input end of the signal analog-digital conversion unit, the output end of the signal analog-digital conversion unit is connected with the input end of the digital signal processing unit, the output end of the digital signal processing unit is connected with the input end of the direct current power supply protection subsystem, the output end of the power supply unit is connected with the input end of the signal analog-digital conversion unit and the digital signal processing unit for power supply, the digital signal processing unit directly communicates with the direct current power supply protection subsystem, and the direct current power supply protection subsystem protects the direct current power supply output by the digital signal processing unit.

[0009] The signal acquisition unit acquires the voltage across the thyristor and performs voltage division processing, the rectification filtering unit converts the alternating voltage obtained after voltage division of the signal sampling unit into direct current voltage and performs filtering processing, the signal analog-digital conversion unit converts the filtered direct current voltage signal into a digital signal, the digital signal processing unit processes the digital signal and simultaneously judges the processed signal and outputs an alarm signal, and the direct current power supply protection subsystem judges the alarm signal to realize operation protection of the direct current power supply.

[0010] The signal acquisition unit reduces the alternating voltage across the thyristor through the built-in voltage dividing resistor of the signal acquisition unit, the rectification filtering unit filters the direct current voltage signal through the built-in capacitor, the digital signal processing unit sends the digital signal to the built-in DSP chip, judges and processes the acquired signal to realize real-time detection of the thyristor and operation protection of the direct current power supply.

[0011] The signal sampling unit has a judgment cycle of 20 ms per cycle for the acquisition of the voltage across the thyristor, whether the thyristor fails is reflected by the voltage across the thyristor, and the signal sampling unit acquires the voltage across the thyristor and performs voltage division, and the voltage across the thyristor is reduced to 0-3V.

[0012] The direct current power supply protection subsystem is used for starting control, stopping control and alarm control of the direct current voltage converted from the alternating voltage output by the thyristor.

[0013] A real-time detection method of a high-power arc heater direct current power supply thyristor, comprising:

[0014] Acquiring the voltage across the thyristor through the signal acquisition unit and performing voltage division processing;

[0015] Converting the alternating voltage obtained after voltage division of the signal sampling unit into direct current voltage through the rectification filtering unit and performing filtering processing;

[0016] Converting the filtered direct current voltage signal into a digital signal through the signal analog-digital conversion unit;

[0017] The digital signal processing unit processes the digital signal and judges the processed signal to output an alarm signal;

[0018] The alarm signal is judged by the DC power protection sub-system to realize the operation protection of the DC power.

[0019] The signal sampling unit collects and judges the two-section voltage of the thyristor in a period of 20 ms per cycle; whether the thyristor is faulty is shown by the two-section voltage; after the signal sampling unit collects and divides the two-section voltage of the thyristor, the voltage across the thyristor is reduced to 0-3 V.

[0020] The signal sampling unit reduces the AC voltage across the thyristor by the built-in dividing resistor, the rectification filter unit filters the DC voltage signal by the built-in capacitor, and the digital signal processing unit sends the digital signal to the built-in DSP chip to judge and process the collected signal, so as to realize the real-time detection of the thyristor and the operation protection of the DC power.

[0021] The alarm judgment of the processed signal quantity by the digital signal processing unit is specifically:

[0022] By judging and processing the collected signal, if no voltage signal is found in 1-3 cycles, it is considered that the thyristor has been broken down; the dry contact signal is output by the built-in relay of the digital signal processing unit for alarm processing.

[0023] If the thyristor has been broken down, the fault signal is transmitted by the digital signal processing unit to the DC power protection sub-system to start the protection alarm program, and the DC power is stopped and alarmed in time.

[0024] Compared with the prior art, the advantages of the present application are:

[0025] (1) The real-time detection system and method of the high-power arc heater DC power thyristor provided by the present application can detect the voltage across the thyristor in real time, judge by DSP, and has fast action speed, which makes up for the deficiency of the fast fuse protection, and can also detect the thyristor in standby state, which makes up for the blind area of the fast fuse protection.

[0026] (2) the present application adopts signal sampling unit to collect the voltage of the thyristor, and sends to DSP for operation and judgment, and there is no case that the mechanical micro switch signal cannot be sent; the overall detection system device is small in size, and the protection signal can be sent in time after the thyristor is damaged, the direct fast fuse is avoided to be burnt out, the workload of replacing the fast fuse is reduced, the safe operation of the high-power arc heater DC power supply can be protected, and the power guarantee of the 10MW-50MW level DC heater has important significance. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The arc heater DC power supply schematic diagram provided for the invention is shown in the figure;

[0028] Figure 2 The arc heater DC power supply schematic diagram provided for the invention is shown in the figure; DETAILED DESCRIPTION

[0029] A high-power arc heater DC power supply thyristor real-time detection system and method, by including a thyristor, a signal sampling unit, a rectifier filter unit, a signal analog-digital conversion unit, a digital signal processing unit, a DC power supply protection subsystem, a power supply unit, by analyzing the principle of fast fuse protection, the shortcomings of using fast fuse protection are found out. The digital signal processing technology is adopted, the voltage value of the two ends of the thyristor is detected in real time, so as to realize the judgment of the good or bad of the thyristor.

[0030] The thyristor is the core component of the rectifier unit as shown in Figure 1 The figure shows the basic structure of the arc heater DC power supply and the position of the thyristor element.

[0031] In the real-time detection system, the thyristor is connected with the input end of the signal acquisition unit, the output end of the signal acquisition unit is connected with the input end of the rectifier filter unit, the output end of the rectifier filter unit is connected with the input end of the signal analog-digital conversion unit, the output end of the signal analog-digital conversion unit is connected with the input end of the digital signal processing unit, the output end of the digital signal processing unit is connected with the input end of the DC power supply protection subsystem, the output end of the power supply unit is connected with the input end of the signal analog-digital conversion unit and the digital signal processing unit for power supply, the digital signal processing unit directly communicates with the DC power supply protection subsystem, and the DC power supply protection subsystem protects the DC power supply output by the digital signal processing unit.

[0032] The signal acquisition unit collects the voltage across the thyristor and performs voltage division processing, the rectification and filtering unit converts the AC voltage obtained after voltage division by the signal sampling unit into DC voltage and performs filtering processing, the signal analog-digital conversion unit converts the filtered DC voltage signal into a digital signal, the digital signal processing unit processes the digital signal and simultaneously performs alarm judgment on the processed signal, and outputs an alarm signal; the DC power protection subsystem judges the alarm signal to realize operation protection of the DC power supply.

[0033] Specifically, the signal acquisition unit reduces the AC voltage across the thyristor through the built-in voltage dividing resistor of the signal acquisition unit, the rectification and filtering unit filters the DC voltage signal through the built-in capacitor, the digital signal processing unit sends the digital signal to the built-in DSP chip, judges and processes the collected signal, so as to realize real-time detection of the thyristor and operation protection of the DC power supply.

[0034] The signal sampling unit collects and judges the voltage across the thyristor with a period of 20 ms per cycle; whether the thyristor fails is reflected by the two-section voltage, and after the signal sampling unit collects and divides the voltage across the thyristor, the voltage across the thyristor is reduced to 0-3V.

[0035] The DC power protection subsystem is used for starting control, stopping control and alarm control of the DC voltage converted from the AC voltage output by the thyristor.

[0036] The preferred embodiments will be further described below in conjunction with the drawings in the specification:

[0037] The thyristor is the core power device of the arc heater DC power supply. Once the thyristor fails, the DC power supply will not operate normally, so the detection and protection of the thyristor are particularly important. The traditional scheme is to use a fast fuse for protection and detection. Because the fast fuse does not have a fast enough action speed, it cannot quickly respond to line overcurrent faults, and it is also more likely to cause an accident to expand.

[0038] 1. The fast fuse mainly has a reverse time current protection characteristic. The fuse has a reverse time delay characteristic, that is, when the overload current is small, the melting time is long; when the overload current is large, the melting time is short. Therefore, the protection real-time performance is poor.

[0039] 2. The alarm output of the fast fuse uses a micro switch dry contact signal output. The micro switch is connected to the internal fuse through a lead. When the instantaneous current is too large, the internal fuse of the fast fuse has been melted, but the lead has not been melted, so the micro switch cannot be lifted in time, causing the equipment to operate with a missing phase.

[0040] 3. In a large-capacity DC power supply, the price of a large-current fast fuse is high, and it is not convenient to replace it.

[0041] 4, thyristor has been damaged before the trigger pulse, because there is no trigger pulse, no overcurrent in the line, once running, give trigger pulse, fault current appears in the line. This kind of fault fast fuse can not detect and protect in time.

[0042] The normal working characteristics of thyristor are as follows:

[0043] 1. When the thyristor withstands reverse voltage, whether the gate has trigger signal or not, the thyristor will not open;

[0044] 2. When the thyristor withstands forward voltage, the thyristor can only open in the case that the gate has trigger current;

[0045] 3. Once the thyristor is opened, the gate loses control, and the thyristor always remains open;

[0046] 4. If you want to make the opened thyristor off, you can only add voltage or current through the thyristor below the holding current.

[0047] In the embodiment, the one-way conduction characteristic (unable to open when bearing reverse voltage) of the thyristor is utilized for development.

[0048] In the current embodiment, a large power arc heater DC power thyristor real-time detection system is adopted, as shown in Figure 2 The system is composed of (1) thyristor, (2) signal acquisition unit, (3) rectifier filter unit, (4) signal analog-digital conversion unit, (5) digital signal processing unit, (6) DC power protection subsystem, (7) power supply unit, and is mainly used for real-time detection of thyristor in large power DC power operation.

[0049] The large power arc heater DC power thyristor real-time detection method realized by the real-time detection system has the following specific steps:

[0050] The voltage across the thyristor is acquired by the signal acquisition unit and is divided and processed;

[0051] The alternating voltage obtained after the signal sampling unit is divided by the rectifier filter unit is converted into direct current voltage and is filtered;

[0052] The filtered direct current voltage signal is converted into digital signal by the signal analog-digital conversion unit;

[0053] The digital signal processing unit processes the digital signal and judges the processed signal amount to output an alarm signal;

[0054] The DC power protection subsystem is used to judge the alarm signal to realize the operation protection of the DC power.

[0055] Wherein, the signal sampling unit collects the voltage across the thyristor, and the AC line voltage across the thyristor is reduced to 0-3V through a voltage dividing resistor, and the power and resistance of the voltage dividing resistor can be matched according to the line voltage across the thyristor.

[0056] The 0-3V AC signal obtained by the signal sampling unit through the rectifier filter unit is converted into a DC signal through a rectifier module, and then the DC signal is filtered through a capacitor.

[0057] The 0-3V AC signal obtained by the signal sampling unit through the rectifier filter unit is converted into a DC signal through a rectifier module, and then the DC signal is filtered through a capacitor.

[0058] The signal processing unit sends the digital signal converted by the signal analog-digital conversion unit to a DSP (digital signal processing) chip for judgment and processing of the collected signal. If no voltage signal is found within 1-3 cycles (which can be adjusted), it is considered that the thyristor has been broken down, and a dry contact signal is output through a relay for alarm processing.

[0059] The fault signal is transmitted from the digital signal processing unit to the DC power supply protection subsystem to start the protection alarm program, and the DC power supply is stopped and alarmed in time.

[0060] The power supply unit supplies power to the signal analog-digital conversion unit and the signal processing unit.

[0061] Specifically, the thyristor is a high-power power electronic component with unidirectional conduction characteristics. When the thyristor is on standby or working normally, the voltage across the thyristor A (anode) and K (cathode) will not be zero. Only when the thyristor is damaged, the resistance between the thyristor A (anode) and K (cathode) is zero, and at this time, the voltage across the thyristor is zero.

[0062] The signal sampling unit is mainly composed of a sampling resistor, which reduces the AC line voltage across the thyristor to 0-3V.

[0063] The rectifier filter unit is composed of a rectifier module and a capacitor inductor filter circuit, which rectifies the AC voltage collected by the signal sampling unit into a DC signal.

[0064] The signal analog-digital conversion unit is an A / D conversion module that converts the DC analog signal output by the rectifier filter unit into a digital signal.

[0065] The signal processing unit is built-in DSP (digital signal processing) chip, which processes and judges the digital signal.

[0066] The DC power supply protection subsystem is a protection platform for safe operation of the DC power supply and arc heater, which is developed by integrating various software and hardware.

[0067] The power supply unit is a direct current 24V power supply, and the primary side is taken from the rectifier transformer synchronous voltage, and the signal analog-digital conversion unit and the signal processing unit are powered.

[0068] By analyzing the principle of the fast fuse protection, the deficiencies of using the fast fuse protection are found out. By using the digital signal processing technology, the voltage value between the two ends of the thyristor is detected in real time, so that the judgment of the good or bad of the thyristor is realized, and the following is realized:

[0069] 1. The voltage value between the two ends of the thyristor is detected in real time, and the operation is judged by the DSP, so that the speed is fast, and the deficiencies of the fast fuse protection are well made up;

[0070] 2. The thyristor in standby state can be detected, and the blind area of the fast fuse protection is made up;

[0071] 3. By collecting the voltage between the two ends of the thyristor, the operation is judged by the DSP, and the situation that the mechanical micro switch signal cannot be sent does not exist;

[0072] 4. The device is small in size, the protection signal can be sent in time after the thyristor is damaged, the fast fuse is avoided to be directly burnt out, and the workload of replacing the fast fuse is reduced.

[0073] The technical problem solved by the further application is: protecting the safe operation of the high-power arc heater direct-current power supply, which is of great significance for the power guarantee of 10MW-50MW level direct-current heater.

[0074] Although the application has been disclosed as above with the preferred embodiments, it is not intended to limit the application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the application by using the disclosed methods and technical contents without departing from the spirit and scope of the application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the application, which does not deviate from the technical solutions of the application, belongs to the protection scope of the technical solutions of the application.

[0075] The contents not described in detail in the specification of the application belong to the known technology of those skilled in the art.

Claims

1. A high-power arc heater DC power supply thyristor real-time detection system, characterized in that: it comprises a thyristor, a signal acquisition unit, a rectification filter unit, a signal analog-digital conversion unit, a digital signal processing unit, a DC power supply protection subsystem, and a power supply unit, wherein: the thyristor is connected with the input end of the signal acquisition unit, the output end of the signal acquisition unit is connected with the input end of the rectification filter unit, the output end of the rectification filter unit is connected with the input end of the signal analog-digital conversion unit, the output end of the signal analog-digital conversion unit is connected with the input end of the digital signal processing unit, the output end of the digital signal processing unit is connected with the input end of the DC power supply protection subsystem, the output end of the power supply unit is connected with the input end of the signal analog-digital conversion unit and the digital signal processing unit for power supply, the digital signal processing unit directly communicates with the DC power supply protection subsystem, and the DC power supply protection subsystem protects the DC power supply output by the digital signal processing unit; the signal acquisition unit acquires the voltage across the thyristor and performs voltage division processing, the rectification filter unit converts the AC voltage obtained after voltage division of the signal acquisition unit into DC voltage and performs filtering processing, the signal analog-digital conversion unit converts the filtered DC voltage signal into a digital signal, the digital signal processing unit processes the digital signal, simultaneously judges the processed signal and outputs an alarm signal, and the DC power supply protection subsystem judges the alarm signal to realize operation protection of the DC power supply; the signal acquisition unit reduces the AC voltage across the thyristor through the built-in voltage dividing resistor of the signal acquisition unit, the rectification filter unit filters the DC voltage signal through the built-in capacitor, the digital signal processing unit sends the digital signal to the built-in DSP chip, judges and processes the collected signal to realize real-time detection of the thyristor, and realizes operation protection of the DC power supply; the signal acquisition unit acquires and judges the voltage across the thyristor with a cycle of 20 ms per cycle, whether the thyristor fails is reflected by the voltage across the thyristor, and after the signal acquisition unit acquires and divides the voltage across the thyristor, the voltage across the thyristor is reduced to 0-3 V; the DC power supply protection subsystem is used for starting control, stopping control, and alarm control of the DC voltage converted from the AC voltage output by the thyristor; when the thyristor bears a reverse voltage, the thyristor will not be turned on regardless of whether there is a trigger signal at the gate, when the thyristor bears a forward voltage, the thyristor can be turned on only when there is a trigger current at the gate, once the thyristor is turned on, the gate loses control, and the thyristor always remains in the turned-on state, and the only way to turn off the turned-on thyristor is to apply an external voltage or a current lower than the holding current to the thyristor. It comprises: acquiring the voltage across the thyristor through the signal acquisition unit and performing voltage division processing; converting the AC voltage obtained after voltage division of the signal acquisition unit into DC voltage through the rectification filter unit and performing filtering processing; converting the filtered DC voltage signal into a digital signal through the signal analog-digital conversion unit; processing the digital signal, simultaneously judging the processed signal, and outputting an alarm signal through the digital signal processing unit; ​ ​ 2. The real-time detection method of the high-power arc heater DC power supply thyristor realized by the real-time detection system according to claim 1, characterized in that ​ ​ ​ ​ ​ The alarm signal is judged by using the DC power supply protection sub-system to realize the operation protection of the DC power supply; The signal acquisition unit collects and judges the voltage across the thyristor in a period of 20ms per cycle; Whether the thyristor is faulty is reflected by the voltage across the thyristor, and after the signal acquisition unit collects and divides the voltage across the thyristor, the voltage across the thyristor is reduced to 0-3V; The signal acquisition unit reduces the AC voltage across the thyristor by the built-in voltage dividing resistor, the rectifier filter unit filters the DC voltage signal by the built-in capacitor, and the digital signal processing unit sends the digital signal to the built-in DSP chip to judge and process the collected signal, so as to realize real-time detection of the thyristor and operation protection of the DC power supply; The alarm judgment of the digital signal processing unit on the processed signal is as follows: Through the judgment and processing of the collected signal, if no voltage signal is found in 1-3 cycles, it is considered that the thyristor has been broken down, and the digital signal processing unit outputs the contact signal for alarm processing; If the thyristor has been broken down, the digital signal processing unit transmits the fault signal to the DC power supply protection sub-system to start the protection alarm program, and the DC power supply stops running and alarms in time; The digital signal processing unit transmits the fault signal to the DC power supply protection sub-system to start the protection alarm program, and the DC power supply stops running and alarms in time; The power supply unit supplies power to the signal A / D conversion unit; Specifically, the thyristor is a high-power power electronic component with the characteristic of unidirectional conduction. When the thyristor is on standby or working normally, the voltage across the A anode and K cathode of the thyristor is not zero. Only when the thyristor is damaged, the resistance between the A anode and K cathode of the thyristor is zero, and at this time, the voltage across the thyristor is zero.

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