CN113671337A - Silicon controlled rectifier failure detection alarm device, system and test method - Google Patents

Abstract

The invention discloses a silicon controlled failure detection alarm device, which comprises a control circuit, a detection circuit and a normally closed switch circuit, wherein the detection circuit and the normally closed switch circuit are electrically connected with the control circuit; the detection circuit is used for sampling the current value in the circuit and transmitting the control circuit; the control circuit is used for receiving and processing the current value transmitted by the detection circuit, acquiring a waveform state corresponding to the current value within preset time, and sending a control signal to the normally closed switch circuit when the thyristor is determined to be in a punctured failure state according to the waveform state; and the normally closed switch circuit is used for controlling the normally closed switch circuit to be disconnected and cutting off the circuit current after receiving the control signal of the control circuit. The invention effectively protects the safety of the circuit, prevents the negative influence caused by short circuit and overcurrent of the controllable silicon, improves the working efficiency of personnel and reduces the risk level of accidents.

Description

Silicon controlled rectifier failure detection alarm device, system and test method

Technical Field

The invention relates to the technical field of electronic equipment, in particular to a silicon controlled failure detection alarm device, a silicon controlled failure detection alarm system and a silicon controlled failure detection test method.

Background

With the continuous improvement of the requirements of the whole machine on EMC (lightning surge resistance) in recent years, the need of carrying out corresponding lightning surge resistance tests on a key electronic switching element, namely, a silicon controlled rectifier, is promoted. However, the original silicon controlled rectifier is not examined on the performance parameter, which means that the lightning stroke surge examination needs to be carried out on the silicon controlled rectifier under the national standard (GB/T17626.5-1999) test condition, so that the limit lightning stroke resistance of the silicon controlled rectifier is known and is provided for circuit designers to use for reference.

However, the test schemes required in the current national standard are all schemes for testing the whole machine, and no scheme for testing the silicon controlled rectifier alone is provided. The mainstream silicon controlled rectifier lightning surge performance test scheme in the current market is as follows: the lightning surge generator, the high-power load and the tested silicon controlled rectifier are combined, and the tester can judge and process various abnormal changes of the silicon controlled rectifier after being struck by lightning in time in the testing process so as to carry out corresponding operation.

Meanwhile, the existing silicon controlled rectifier foundation lightning surge test scheme can only generate a lightning surge signal through lightning equipment and apply the lightning surge signal to the silicon controlled rectifier. Particularly, in the process of testing the lightning stroke performance of the silicon controlled rectifier, the silicon controlled rectifier lightning stroke performance testing device does not have the functions of silicon controlled rectifier failure detection and lightning stroke equipment protection.

And present basic test scheme wants to know fast whether the silicon controlled rectifier receives the thunderbolt surge damage to do not influence the test result accuracy and play the purpose of protection thunderbolt equipment, can only adopt artifical real-time supervision mode: the lightning stroke equipment is externally connected with detection equipment (such as an oscilloscope, a pincerlike ammeter and the like), the reading of the equipment is monitored in real time by personnel, so that whether the silicon controlled rectifier is switched on by mistake or damaged is judged, and under the premise that the silicon controlled rectifier is damaged, the lightning stroke equipment is powered off in a manual mode by the personnel, so that the lightning stroke equipment is prevented from being burnt by short circuit of the equipment.

In addition, if the existing leakage protector is adopted to carry out protection work, as the sensitivity of the leakage protector is too high and the lightning-resistant capability is weak, the leakage protector can trip or even fail as long as the malfunction of the silicon controlled rectifier occurs or the tested lightning voltage is too high, and the effective circuit protection and test functions cannot be achieved at all.

Disclosure of Invention

The invention provides a thyristor failure detection alarm device, a thyristor failure detection alarm system and a thyristor failure detection test method aiming at one or more of the existing problems.

According to a first aspect of the present invention, there is provided a thyristor failure detection alarm device comprising: the detection circuit is electrically connected with the control circuit;

the detection circuit is used for sampling the current value in the circuit and transmitting the control circuit;

the control circuit is used for receiving and processing the current value transmitted by the detection circuit, acquiring a waveform state corresponding to the current value within preset time, and sending a control signal to the normally closed switch circuit when the thyristor is determined to be in a punctured failure state according to the waveform state;

and the normally closed switch circuit is electrically connected with the detection circuit and is used for controlling the normally closed switch circuit to be disconnected and cutting off the circuit current after receiving the control signal of the control circuit.

In some possible design modes, the alarm device further comprises an alarm circuit and a power supply circuit, and the power supply circuit is electrically connected with the control circuit and the alarm circuit. The alarm circuit is configured to perform alarm prompting after receiving a control signal of the control circuit.

In some possible designs, the control circuit further includes a reset circuit, and the reset circuit is electrically connected to the control circuit.

IN some possible designs, the alarm device further includes a first input terminal IN1 and a second input terminal IN2, the detection circuit employs a current transformer, the first input terminal IN1 is connected to the normally closed switch circuit through a magnetic ring of the current transformer, and the second input terminal IN2I is connected to the other end of the normally closed switch circuit.

In a second aspect, the present invention provides a silicon controlled rectifier failure detection alarm system, comprising:

the detection alarm device, the lightning strike equipment, the tested silicon controlled rectifier and the voltage control resistor R,

the lightning strike device is configured to provide a power signal to the detection alarm means having a frequency and amplitude in sinusoidally alternating cycles, and to superimpose on the power signal a combination wave of an analog lightning strike voltage and current of adjustable amplitude,

one end of the lightning stroke equipment is electrically connected with a normally closed switch circuit in the detection alarm device through the tested silicon controlled rectifier, and the other end of the lightning stroke equipment is electrically connected with the input end of the detection alarm device.

In some possible designs, the lightning protection device further comprises a load current limiting circuit, and the load current limiting circuit is connected between the lightning strike device and a detection circuit in the detection alarm device in series.

In some possible design modes, the thyristor voltage-controlled circuit further comprises a voltage-controlled resistor R, wherein the voltage-controlled resistor R is connected in parallel with two ends of a control electrode and a cathode of the tested thyristor or two ends of the control electrode and a first anode, and is used for ensuring that the thyristor is in a normal and effective turn-off state.

In a third aspect, the present invention provides a testing method for a silicon controlled failure detection alarm system, which comprises the following steps:

outputting an effective alternating current power supply signal by using lightning stroke equipment;

simulating and outputting a voltage wave for testing to be superposed on an alternating current power supply signal by using lightning stroke equipment, and applying the voltage wave to a cathode and an anode or a first anode and a second anode of the tested silicon controlled rectifier;

acquiring the current state flowing through the tested controlled silicon;

and controlling the on-off of the normally closed switch circuit according to the current state flowing through the tested controlled silicon and determining whether to give an alarm or not.

In some possible design modes, the detection alarm device controls the on-off of the normally closed switch circuit and confirms whether to give an alarm or not according to the state of the detected silicon controlled rectifier, and the detection alarm device specifically comprises:

when the detected silicon controlled rectifier is detected to generate a corresponding induced current only when the equipment corresponding to the lightning stroke is struck by the lightning, no current flows through the silicon controlled rectifier at other time, and the normally closed switch circuit does not cut off the circuit and does not give an alarm to prompt;

when the detected silicon controlled rectifier is detected to be switched on by lightning voltage when corresponding lightning equipment is struck by lightning, but is switched off to the zero position of the next alternating current power supply signal, namely the silicon controlled rectifier switching-on time is less than the preset time, and the normally closed switch circuit does not cut off the circuit and does not give an alarm prompt;

when the detected silicon controlled rectifier is detected to be broken down and conducted by lightning voltage when the detected silicon controlled rectifier is struck by lightning corresponding to the lightning equipment and is in a always-on state, the conduction time is longer than the preset time, and the detection alarm device controls the normally-closed switch circuit to be disconnected and cuts off the circuit current.

The invention has the beneficial effects that:

the invention provides a silicon controlled failure detection alarm device, which converts a larger short-circuit current into a micro current through an isolated current transformer and sends the micro current to a control circuit for identification, the control circuit receives and processes a current value transmitted by a detection circuit and obtains a waveform state corresponding to the current value within a preset time, a control signal is sent to a normally closed switch circuit when the silicon controlled failure state is confirmed to be a punctured failure state according to the waveform state, and the normally closed switch circuit controls the normally closed switch circuit to be disconnected after receiving the control signal of the control circuit, cuts off the circuit current and gives an alarm. Therefore, the safety of the circuit is effectively protected, negative effects (such as failed silicon controlled rectifier secondary explosion caused by overcurrent, lightning stroke test equipment damage and the like) caused by short circuit and overcurrent of the silicon controlled rectifier are prevented, the working efficiency of personnel is improved, and the risk level of accident occurrence is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a thyristor failure detection alarm device;

FIG. 2 is a schematic structural diagram of a silicon controlled failure detection alarm system;

FIG. 3 is a schematic circuit diagram of a thyristor failure detection alarm device;

FIG. 4 is a flow chart of a testing method of the SCR failure detection alarm system;

fig. 5 is a schematic view of a current waveform of a tested thyristor in a testing method of the thyristor failure detection alarm system.

With the foregoing drawings in mind, certain embodiments of the disclosure have been shown and described in more detail below. These drawings and written description are not intended to limit the scope of the disclosed concepts in any way, but rather to illustrate the concepts of the disclosure to those skilled in the art by reference to specific embodiments.

Detailed Description

The technical scheme of the application is further explained in detail with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Some embodiments of the invention are described in detail below with reference to the accompanying drawings. In case of conflict, features of the following embodiments and embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Example one

FIG. 1 is a schematic structural diagram of a silicon controlled failure detection alarm device according to an embodiment of the present invention; this embodiment provides silicon controlled rectifier failure detection alarm device, and normally closed switch in fig. 1 refers to the normally closed switch circuit in this application, and the power supply refers to the power supply circuit of this application, includes: the control circuit 1, and a detection circuit 2 and a normally closed switch circuit 3 which are electrically connected with the control circuit 1;

the detection circuit 2 is used for sampling the current value in the circuit and transmitting the control circuit 1;

the control circuit 1 is used for receiving and processing the current value transmitted by the detection circuit, acquiring a waveform state corresponding to the current value within a preset time, and sending a control signal to the normally closed switch circuit when the thyristor is determined to be in a punctured failure state according to the waveform state;

and the normally closed switch circuit 3 is electrically connected with the detection circuit and is used for disconnecting the normally closed switch circuit and cutting off the circuit current after receiving the control signal of the control circuit 1, so that the circuit is normally in a normally closed state by adopting the normally closed switch circuit, and the whole test circuit loop can be disconnected after receiving the action signal sent by the control circuit.

In some possible design modes, the intelligent alarm device further comprises an alarm circuit 4, a power supply circuit 5 and a reset circuit 6, wherein the alarm circuit 4 is configured to give an alarm prompt after receiving a control signal of the control circuit; the power supply circuit is electrically connected with the control circuit and the alarm circuit and used for supplying power; the reset circuit 5 is electrically connected with the control circuit 1 and the normally closed switch circuit 3 and is used for enabling the whole failure detection alarm device to work normally again after the failed tested silicon controlled rectifier is eliminated. Specifically, the alarm circuit 4 is used for reminding a tester in two forms of sound and light after the tested silicon controlled rectifier is broken down and short-circuited by the lightning stroke signal.

As shown in fig. 3, the detection circuit 2 may employ a current transformer TA for non-contact sampling of the value of the current flowing through the main circuit to the control circuit. The two ends of the current transformer TA are connected in parallel with a regulating resistor RZ, the control circuit comprises a rectifying circuit, a filter circuit, a main control chip and an alternating current optical coupling circuit, the rectifying circuit adopts a rectifying bridge, the filter circuit adopts a filter capacitor C4, the two ends of the output side of the current transformer TA are connected to the alternating current input end of the rectifying bridge as the alternating current input end, and the direct current output end of the unidirectional pulsating voltage of the rectifying bridge is connected in parallel with a filter capacitor C4. In this embodiment, the filtered detection signal is input into the main control chip U1, and is compared with an internal preset value. When certain conditions are met, a control signal is output to the base electrodes of the R2 and the triode Q1 through the I/O port of the main control chip U1, the collector electrode of the triode Q1 is pulled up to a 5V power supply through the resistor R3, and the triode Q1 is in a saturated conduction state. As shown in the figure, the ac opto-coupler circuit adopts an ac opto-coupler chip U2, and the ac opto-coupler chip U2 applies power and an electric signal to make the light emitting diode emit light, specifically, the light emitting diode of the ac opto-coupler chip U2 is used as an input terminal, one end of the light emitting diode is connected with the emitter of the triode Q1, and the other end of the light emitting diode is connected with GND. One end of the output end of the alternating current photoelectric coupling chip U2 is connected to the anode or the second anode of the silicon controlled switch through the resistor R4, the other end of the output end of the alternating current photoelectric coupling chip U2 is connected to the control electrode of the silicon controlled switch, and the cathode or the first anode of the silicon controlled switch is connected to the normally closed switch circuit. The alternating current photoelectric coupling chip U2 can adopt a chip MOC3052 series or a MOC3062 series or a replacement chip with the same function. The alternating current photoelectric coupling chip U2 is adopted to isolate the input circuit and the output circuit, and the electric signal has the advantages of unidirectionality and the like during transmission, so that the photoelectric coupler has good electromagnetic interference resistance and electric insulation capability and is safer.

As shown in fig. 3, a power structure diagram is provided, in which a power line N represents a zero line and L represents a live line. The power supply adopts the most common full-bridge rectification circuit and three-terminal voltage stabilizer for voltage stabilization. The L terminal, the N terminal and the X terminal shown in different figures represent the same endpoint information. The normally closed switch circuit adopts a double-pole double-throw linked normally closed switch, one end of a relay coil KA of the normally closed switch is connected with a power line N, and the other end of the relay coil is connected with a silicon controlled switch. The alarm device further comprises a first input end IN1 and a second input end IN2, wherein the IN1 is connected with the switch contact 2 after penetrating through a magnetic ring of the current transformer through a lead, the IN2 is connected with the switch contact 6, the switch contact 6 is IN closed connection with the contact 2, and the switch contact 5 is IN closed connection with the contact 1. Reset circuit adopts the normal close switch that dabs of taking the lamp, including power indicator and reset switch, the first function of realizing power indication, the second is reset device after pressing, let the device can normally work again, in this embodiment, the output of contact 1 and reset circuit's power indicator electric connection, power indicator's other end electric connection power cord N, reset circuit's normal close switch one end and live wire L electric connection, normal close switch one end linked switch contact 5 and silicon controlled switch Q2.

Under the normal state, the power is switched on, the circuit is IN a working state, the normally closed switch circuit is always IN a normally closed state, namely the switch contact 6 is IN closed connection with the contact 2, the tested silicon controlled rectifier is IN an effective turn-off state, but after the tested silicon controlled rectifier is broken down by lightning stroke test voltage, current always flows between the IN1 and the IN2, the current transformer TA detects a current signal and then carries out comparison judgment on the current signal through rectification and filtering to the main control chip U1, a signal is output to drive the triode Q1 to amplify the signal and then send the amplified signal to the AC optocoupler U2, the switch silicon controlled rectifier Q2 is enabled to be switched on, the normally closed switch (the switch contact 6 and the contact 2) corresponding to the coil of the relay KA is powered on is switched off, the main loop current is switched off, meanwhile, the corresponding normally open switch (the switch contact 5 and the contact 3) is switched on, and the alarm circuit is triggered to be powered on to work, and accordingly an operator is reminded.

After the tested failure thyristor is removed, a new tested thyristor is replaced, the touch switch KM of the reset circuit is pressed down, so that the normally closed switch KM is instantly disconnected, the voltage drop at two ends of the thyristor switch Q2 is 0V, the thyristor switch Q2 is automatically powered off, the relay KA coil is powered off, the whole detection alarm device is automatically reset, and a new round of test can be started.

In the embodiment, the device converts a large short-circuit current into a small current through an isolated current transformer and sends the small current to the control circuit for identification, the control circuit receives and processes a current value transmitted by the detection circuit, obtains a waveform state corresponding to the current value within a preset time, and sends a control signal to the normally closed switch circuit when the thyristor is determined to be in a breakdown failure state according to the waveform state, and the normally closed switch circuit controls the normally closed switch circuit to be disconnected after receiving the control signal of the control circuit, cuts off the circuit current and gives an alarm.

Therefore, the safety of the circuit is effectively protected, negative effects (such as failed silicon controlled rectifier secondary explosion caused by overcurrent, lightning stroke test equipment damage and the like) caused by short circuit and overcurrent of the silicon controlled rectifier are prevented, the working efficiency of personnel is improved, and the risk level of accident occurrence is reduced.

Example two

As shown in fig. 2, the present invention provides a thyristor failure detection alarm system, where a in fig. 2 is the thyristor failure detection alarm device provided in embodiment 1, the system includes: the silicon controlled rectifier failure detection alarm device, the lightning strike equipment, the tested silicon controlled rectifier and the voltage control resistor R in the first embodiment are adopted.

The lightning strike device is configured to provide a power signal to the thyristor under test at a frequency and amplitude in a sinusoidally alternating cycle, and to superimpose on the power signal a combined wave of an analog lightning strike voltage and current of adjustable amplitude,

one end of the lightning stroke equipment is electrically connected with a normally closed switch circuit in the detection alarm device through a tested silicon controlled rectifier, and the other end of the lightning stroke equipment is electrically connected with an input end of the detection alarm device, wherein the tested silicon controlled rectifier can be any known silicon controlled rectifier, including but not limited to a unidirectional silicon controlled rectifier, a bidirectional silicon controlled rectifier and the like.

As shown in fig. 2, the lightning protection device further comprises a load current limiting circuit which is connected in series between the lightning strike equipment and the detection circuit in the detection alarm device.

As shown in fig. 2, the thyristor further includes a voltage-controlled resistor R, and the voltage-controlled resistor R is connected in parallel to two ends of the control electrode and the cathode or two ends of the control electrode and the first anode of the thyristor to be tested, and is used for ensuring that the thyristor is in a normal and effective turn-off state.

The silicon controlled rectifier failure detection alarm system provided by the embodiment adopts the matched connection of the lightning stroke equipment and the detection alarm device, so that the lightning stroke equipment provides the detection alarm device with a power supply signal with the frequency and the amplitude in a sine alternating period, and a combined wave of simulating lightning stroke current with adjustable amplitude is superposed on the power supply signal.

EXAMPLE III

As shown in fig. 4, the invention provides a testing method of a thyristor failure detection alarm system, which comprises the following steps:

s100, outputting an effective alternating current power supply signal by using lightning equipment;

s200, simulating and outputting a voltage wave for testing by using lightning stroke equipment, superposing the voltage wave on an alternating current power supply signal according to a preset angle, and applying the voltage wave to a cathode and an anode or between a first anode and a second anode of the tested controlled silicon;

s300, acquiring the current state of the tested silicon controlled rectifier;

and S400, controlling the on-off of the normally closed switch circuit and determining whether to give an alarm prompt or not by the detection alarm device according to the current state flowing through the tested controlled silicon.

As shown in the figure, adopt above-mentioned silicon controlled rectifier failure detection alarm system, step detection alarm device is according to the break-make of the state control normally closed switch circuit of the silicon controlled rectifier of quilt survey and whether confirm to report to the police the suggestion, specifically includes:

the detected silicon controlled rectifier generates a corresponding induced current only when the corresponding lightning equipment is struck by lightning, no current flows through the silicon controlled rectifier at other time, and the normally closed switch circuit does not cut off the circuit current and does not give an alarm prompt;

when the detected silicon controlled rectifier is detected to be switched on by lightning voltage when corresponding lightning equipment is struck by lightning, but is switched off to the zero position of the next alternating current power supply signal, namely the silicon controlled rectifier switching-on time is less than the preset time, and the normally closed switch circuit does not cut off the circuit current and does not give an alarm prompt;

and when the detected silicon controlled rectifier is detected to be broken down and conducted by lightning voltage when the detected silicon controlled rectifier is struck by lightning corresponding to the lightning equipment, and the conduction time is longer than the preset time, the normally closed switch circuit of the detection alarm device is controlled to be disconnected, and the circuit current is cut off.

As shown in the figure, according to the test condition of national standard (GB/T17626.5-1999), the lightning strike device can generate a voltage wave (Vmax) with a certain amplitude to be superimposed on an alternating current power supply signal, and the voltage wave is applied to two ends of the main pole of the tested thyristor, which is found to cause the thyristor to present three states: in the state 1, the tested silicon controlled rectifier does not act, and only a large lightning induced current can instantaneously flow through the tested silicon controlled rectifier; in the state 2, the silicon controlled rectifier is conducted in a false action mode until the alternating current power supply signal is turned off after zero crossing; and in the state 3, the tested controlled silicon is broken down and conducted, and the current is continued all the time.

For example, a lightning stroke device generates an alternating current signal of 220V/50Hz, and the frequency of the lightning stroke surge signal is 1 minute/time, and each time is a positive lightning stroke surge signal.

As shown in fig. 5: fig. 5 is a waveform diagram of current flowing through the thyristor under test, Uin is a waveform of an alternating current power supply on which a lightning voltage signal is superimposed, lout1 is a waveform diagram of a lightning current wave in a state 1, lout2 is a waveform diagram of a lightning current wave in a state 2, and lout3 is a waveform diagram of a lightning current wave in a state 3.

State 1: when lightning voltage appears at 90 degrees of an alternating current signal, the tested controlled silicon is forced to be conducted for a moment, a peak current with the peak value of Imax1 flows through the controlled silicon, the current depends on the lightning voltage and the resistance value of a high-power load, the tested controlled silicon is still in a turn-off state in the rest time, and the effective value of the current flowing through the controlled silicon is zero. The current transformer only detects an instantaneous current signal formed after the lightning strike and transmits the instantaneous current signal to the control circuit, and the control circuit judges that the instantaneous current is a normal lightning strike induced current which is a normal phenomenon and does not act, and the alarm circuit is still in a standby state.

State 2: when lightning stroke voltage appears at 90 degrees of an alternating current signal, the tested silicon controlled rectifier is forced to be conducted for 5ms, the tested silicon controlled rectifier is automatically turned off after the current flowing through the tested silicon controlled rectifier from the occurrence of the lightning stroke signal is smaller than the maintaining current of the tested silicon controlled rectifier, a peak current with the peak value of Imax2 flows on the tested silicon controlled rectifier, the current peak value depends on the lightning stroke voltage and the resistance value of a high-power load resistor, the silicon controlled rectifier is still in a turn-off state in the rest time except the forced conduction time that current flows through the silicon controlled rectifier within 5ms, and the effective value of the current flowing through the silicon controlled rectifier is zero. The current transformer only detects that a current signal is generated within 5ms after lightning stroke and transmits the current signal to the control circuit, and the control circuit judges that the current value is the normal malfunction current of the silicon controlled rectifier, is a normal phenomenon and does not act, and the alarm circuit is still in a standby state.

State 3: when lightning stroke voltage appears at 90 degrees of the alternating current signal, the tested silicon controlled rectifier is broken down by the lightning stroke surge voltage, and the tested silicon controlled rectifier fails. Therefore, the tested silicon controlled rectifier loses the most basic zero-crossing turn-off function, the tested silicon controlled rectifier is always in a normally-on state and can generate an effective current signal changing along with an alternating current signal, the effective current value of the tested silicon controlled rectifier depends on an alternating current voltage value and a high-power load resistance value, the working time of the tested silicon controlled rectifier is more than 5ms, the current transformer detects the alternating effective current and transmits the alternating effective current to the control circuit, the control circuit judges that the current value is short-circuit working current generated after the silicon controlled rectifier fails, and the control circuit immediately sends a control signal to the normally-closed switch circuit to turn off a main loop and simultaneously sends a signal to the alarm circuit to give an alarm prompt to inform a tester of eliminating the abnormal state.

Therefore, according to the type of the tested silicon controlled rectifier, the high-power load resistance value is selected, and after the circuit is normally connected, the silicon controlled rectifier failure detection alarm device is connected in series and enters a loop. The power supply of the device is electrified, after a lightning stroke signal output by lightning stroke equipment is set according to the test requirement, the device starts to output waveforms, the current transformer detects the current flowing through a loop in real time, and when the current in the circuit is detected to be in a first waveform state and a second waveform state, the device does not act; and only when the third state is detected, the control circuit acts, the output signal disconnects the normally closed switch, and meanwhile, the output signal gives an alarm prompt to the alarm circuit to inform a tester that the silicon controlled rectifier of the tested element is broken down by lightning surge and fails to conduct.

Besides, the lightning stroke resistance of the tested silicon controlled rectifier can be effectively quantized by adjusting the amplitude of lightning stroke surge voltage.

The waveforms of the lightning strike signals mentioned in the present application are shown in the figure and are all given according to the IEC61000-4-5 standard, wherein the ac signals generated by the lightning strike device, the frequency of the lightning strike signals, and the angle of each superposition can be adjusted according to the requirements of the actual test, and are not limited to the above exemplary values.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

What has been described above are merely some embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept thereof, and these changes and modifications can be made without departing from the spirit and scope of the invention.

Claims (9)

1. Silicon controlled rectifier failure detection alarm device, its characterized in that includes: the device comprises a control circuit (1), and a detection circuit (2) and a normally closed switch circuit (3) which are electrically connected with the control circuit (1);

the detection circuit (2) is used for sampling the current value in the circuit and transmitting the control circuit (1);

the control circuit (1) is used for receiving and processing the current value transmitted by the detection circuit, acquiring a waveform state corresponding to the current value within preset time, and sending a control signal to the normally closed switch circuit (3) when the thyristor is determined to be in a punctured failure state according to the waveform state;

and the normally closed switch circuit (3) is electrically connected with the detection circuit and is used for disconnecting the normally closed switch circuit and cutting off the circuit current after receiving the control signal of the control circuit (1).

2. The silicon controlled rectifier failure detection alarm device according to claim 1, characterized by further comprising an alarm circuit (4) and a power circuit (5), wherein the power circuit (5) is electrically connected with the control circuit (1) and the alarm circuit (4), and the alarm circuit (4) is configured to give an alarm prompt after receiving a control signal of the control circuit (1).

3. The silicon controlled rectifier failure detection alarm device according to claim 1, characterized by further comprising a reset circuit (5), wherein the reset circuit (5) is electrically connected with the control circuit (1) and the normally closed switch circuit (3).

4. The scr fail detection alarm device according to claim 1, wherein the alarm device comprises a first input terminal IN1 and a second input terminal IN2, the detection circuit (2) employs a current transformer, the first input terminal IN1 is connected to the normally closed switch circuit (3) through a magnetic ring of the current transformer, and the second input terminal IN2I is connected to the other end of the normally closed switch circuit (3).

5. Silicon controlled rectifier failure detection alarm system, its characterized in that includes: the detection alarm device, lightning strike equipment, thyristor to be tested and voltage-controlled resistor R according to any one of claims 1 to 4,

the lightning strike device is configured to provide a power signal to the thyristor under test at a frequency and amplitude in a sinusoidally alternating cycle, and to superimpose on the power signal a combined wave of an adjustable amplitude analog lightning strike voltage and current,

one end of the lightning stroke equipment is electrically connected with a normally closed switch circuit in the detection alarm device through the detected silicon controlled rectifier, and the other end of the lightning stroke equipment is electrically connected with the input end of the detection alarm device.

6. The silicon controlled rectifier failure detection alarm system of claim 5, further comprising a load current limiting circuit connected in series between the lightning strike device and the detection circuit in the detection alarm device.

7. The silicon controlled rectifier failure detection alarm system of claim 6, further comprising a voltage control resistor R, wherein the voltage control resistor R is connected in parallel to two ends of the control electrode and the cathode or two ends of the control electrode and the first anode of the silicon controlled rectifier to be tested, and is used for ensuring that the silicon controlled rectifier is in a normal and effective turn-off state.

8. The testing method of the silicon controlled rectifier failure detection alarm system is characterized in that the silicon controlled rectifier failure detection alarm system of any one of claims 5 to 6 is adopted, and the method comprises the following steps:

outputting an effective alternating current power supply signal by using lightning stroke equipment;

simulating and outputting a voltage wave for testing to be superposed on an alternating current power supply signal by using lightning stroke equipment, and applying the voltage wave to a cathode and an anode or a first anode and a second anode of the tested silicon controlled rectifier;

acquiring the state of current flowing through the tested controlled silicon;

and controlling the on-off of the normally closed switch circuit according to the state of the current flowing through the tested controlled silicon and determining whether to give an alarm or not.

9. The testing method of the silicon controlled rectifier failure detection alarm system according to claim 8, wherein the steps of controlling the on-off of the normally closed switch circuit and determining whether to give an alarm according to the state of the tested silicon controlled rectifier specifically include:

when the detected silicon controlled rectifier is detected to generate a corresponding induced current only when the equipment corresponding to the lightning stroke is struck by the lightning, no current flows through the silicon controlled rectifier at other time, and the normally closed switch circuit does not cut off the circuit and does not give an alarm to prompt;

when the detected silicon controlled rectifier is detected to be switched on by lightning voltage when corresponding lightning equipment is struck by lightning, but is switched off to the zero position of the next alternating current power supply signal, namely the silicon controlled rectifier switching-on time is less than the preset time, and the normally closed switch circuit does not cut off the circuit and does not give an alarm prompt;

and when the detected silicon controlled rectifier is detected to be broken down and conducted by lightning voltage when the detected silicon controlled rectifier is struck by lightning corresponding to the lightning equipment, and the conduction time is longer than the preset time, the normally closed switch circuit of the detection alarm device is controlled to be disconnected, and the circuit current is cut off.

Images