Overvoltage photoelectric isolation protection device based on short circuit test

Abstract

The invention discloses an overvoltage photoelectric isolation protection device based on short-circuit test, comprising a photoelectric isolation module, the photoelectric isolation module comprising a resistor voltage divider module, a photoelectric isolator for performing optical coupling on an electrical signal output by the resistor voltage divider module, an overcurrent and overvoltage protection module for performing overcurrent and overvoltage protection on a light-emitting diode packaged in the photoelectric isolator, and a power supply module connected to the photoelectric isolator and supplying power to the photoelectric isolator; the invention adopts a photoelectric isolator, and a dual protection mechanism formed by an overcurrent and overvoltage protection circuit and a reverse protection circuit realizes a protection function in the overvoltage process of short-circuit test, greatly reduces costs, and improves use efficiency; the device fills the gap in domestic technology research and development, and compared with similar imported equipment from abroad, the direct economic benefits it can generate exceed 280,000 yuan, and the cost-effectiveness ratio reaches 4666.67 times, with the obvious advantages of low cost and high efficiency, and has extremely high market promotion value.

Description

Technical Field

[0001] The invention relates to a photoelectric isolation protection device, in particular to an overvoltage photoelectric isolation protection device based on short-circuit testing. Background Art

[0002] Optoelectronic isolators use light as a medium to transmit electrical signals. They have a good isolation effect on input and output electrical signals and are widely used in various circuits. There are many large transient pulses in industrial application environments. These transient pulses will affect data transmission and even damage interconnected devices. In order to obtain error-free data transmission in high-speed fieldbus communication, industrial system design engineers must deal with these interferences. Optoelectronic isolators with insulation isolation functions are usually used to maintain data integrity and protect interconnected devices. At present, there is no research and development of similar products based on short-circuit test overvoltage optoelectronic isolation protection devices in China, nor is there a public disclosure of similar products. Basically, they rely on imported equipment or devices from abroad. However, imported short-circuit test overvoltage optoelectronic isolation protection devices are expensive, easy to damage or destroy, and the equipment maintenance costs are high. For example, according to the price estimate of similar products in the United States, a set of imported optoelectronic isolation devices requires nearly RMB 30,000; in addition, due to the need for imports, the equipment procurement cycle is lengthened, and the operating cost is greatly increased, and the equipment utilization efficiency is greatly reduced. Summary of the invention

[0003] The technical problem solved by the present invention is to overcome the defects of the prior art and provide a short-circuit test overvoltage photoelectric isolation protection device which adopts a photoelectric isolator and forms a dual protection mechanism through an overcurrent and overvoltage protection circuit and a reverse protection circuit to realize the protection function during the short-circuit test overvoltage process and greatly reduce the cost and improve the use efficiency.

[0004] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0005] The overvoltage photoelectric isolation protection device based on short-circuit test includes a photoelectric isolation module, which includes a resistor voltage divider module for sampling the port voltage of a sample under test and dividing the sampled voltage, a photoelectric isolator for optically coupling the electrical signal output by the resistor voltage divider module, an overcurrent and overvoltage protection module for overcurrent and overvoltage protection of a light-emitting diode packaged in the photoelectric isolator, and a power supply module connected to the photoelectric isolator and supplying power to the photoelectric isolator. The resistor voltage divider module, the overcurrent and overvoltage protection module, and the photoelectric isolator are connected in sequence. The photoelectric isolation module formed by the combination of the resistor voltage divider module, the photoelectric isolator, the overcurrent and overvoltage protection module, and the power module is the core of the short-circuit test overvoltage photoelectric isolation protection device of the present invention, which has the following advantages and characteristics: First, the device and the imported equipment or devices of the same type are tested and compared in full real-time waveforms. The test results show that the comparison waveform of the imported equipment has a distortion of more than 1% in waveform distortion, while the waveform synchronization of the device reaches 100%. Therefore, it can be determined that the measurement level of the device has reached the international advanced level, and the actual use effect is higher than the same type of equipment or devices imported from abroad, filling the gap in domestic technology research and development; second, the device measures and compares five voltages of the DC port. By comparing with the direct measurement data of the actual test, the comparison results show that the voltage is completely similar to 100%, far exceeding the expected target before the test; third, the device has been tested by actual measurement tests such as circuit breaker test and steady-state voltage test, and the data collection is complete, far exceeding the expected target before the test; fourth, the device has been tested by power frequency withstand voltage 5000V and impulse withstand voltage 20000V. V test, no overvoltage phenomenon was generated on the output, which can ensure the safety of the subsequent equipment from the perspective of safety, far exceeding the expected goal before the test; fifth, the actual total cost of each set of this device is less than RMB 60, while it costs nearly RMB 30,000 to import a set of the same type of equipment or device from abroad. The total cost of each set of this device is only 1 / 400 of the price of imported equipment or devices of the same type, which can not only meet domestic demand, but also greatly save various costs such as use, operation, and maintenance of each demander, far exceeding the expected goal of technical research and development; sixth, this device can completely isolate the DC overvoltage signal and prevent damage to the acquisition board of the data acquisition system: each acquisition board costs RMB 50,000, and the procurement cycle takes about 3-6 months; taking the example of two acquisition boards burned out after just one month of operation, the acquisition board alone can save RMB 100,000 in equipment maintenance costs; and based on the current workload of various test experiments, if the data acquisition system cannot be used for 3 months, it will cause direct economic losses of more than one million yuan; seventh, the internal parameters of this device have been standardized and normalized, and the conditions for commercial operation have been met.

[0006] Preferably, the overcurrent and overvoltage protection module is provided with an overcurrent and overvoltage protection circuit, and the overcurrent and overvoltage protection circuit includes a first diode, the cathode of the first diode is respectively connected to the anode of the resistor voltage divider module and the light emitting diode, and the anode of the first diode is connected to the cathode of the light emitting diode. If the voltage signal output by the resistor voltage divider module generates an instantaneous voltage value exceeding the normal voltage value when input to the light emitting diode, the first diode is broken down, thereby disconnecting the circuit between the resistor voltage divider module and the light emitting diode by breaking down the first diode, thereby protecting the light emitting diode from being broken down by breaking down the first diode, and thus protecting the photoelectric isolator from being damaged. Since most of the cost of this device is concentrated on the photoelectric isolator element, even if the first diode is broken down and a new first diode needs to be replaced, the first diode is much cheaper than the photoelectric isolator and the first diode is cheap, replacing a first diode is less than 60 yuan, and it is very convenient to replace the first diode, therefore, compared with imported equipment or devices of the same type, it has a huge cost advantage and use value.

[0007] Preferably, the overcurrent and overvoltage protection circuit also includes a first current limiting resistor for limiting the current flowing into the light-emitting diode, and the first current limiting resistor is connected in series between the cathode of the first diode and the anode of the light-emitting diode. The first current limiting resistor is 1KΩ; if the current flowing through the light-emitting diode exceeds the normal current value of the light-emitting diode, the first current limiting resistor limits the current flowing through the light-emitting diode to within the normal current value of the light-emitting diode; due to the current limiting effect of the first current limiting resistor, the light-emitting diode is prevented from being broken down due to excessive current flowing through the light-emitting diode, thereby further protecting the photoelectric isolator. Since the cost of the first current limiting resistor is extremely cheap, it is negligible compared to the cost of the photoelectric isolator and can be ignored compared to imported photoelectric isolation equipment or devices. Even if it is destroyed due to overcurrent, it only needs regular maintenance or updating.

[0008] Preferably, the overcurrent and overvoltage protection circuit further includes an overcurrent and overvoltage protection resistor for limiting the current flowing through the first diode, and the overcurrent and overvoltage protection resistor is connected in series with the anode of the first diode. The overcurrent and overvoltage protection resistor is used to limit the current flowing through the first diode to avoid the first diode being broken down, thereby achieving overcurrent protection for the first diode.

[0009] Preferably, the overcurrent and overvoltage protection resistor includes an adjustable resistor connected in series with the anode of the first diode and capable of adjusting the resistance, and a second current limiting resistor connected in series with the adjustable resistor. The current flowing through the first diode is adjusted by connecting the adjustable resistor in series with the second current limiting resistor, thereby limiting the current flowing through the first diode. The resistance adjustment range of the adjustable resistor is 0-20KΩ, and the second current limiting resistor is 10KΩ. If the current flowing through the first diode exceeds the normal current value of the first diode, the adjustable resistor is increased until the current flowing through the first diode is adjusted to the normal current value. Due to the existence of the overcurrent and overvoltage protection resistor formed by the adjustable resistor and the second current limiting resistor, the current flowing through the first diode is maintained at the normal current value, further ensuring that the first diode will not be broken down, thereby achieving the overcurrent protection effect on the first diode. Since the combined cost of the adjustable resistor and the second current limiting resistor is low, it is negligible compared to the cost of the first diode, and can be ignored compared to imported photoelectric isolation equipment or devices. Even if it is destroyed due to overcurrent, it only needs regular maintenance or updating.

[0010] Preferably, it also includes a reverse protection module for overcurrent protection of the photosensitive semiconductor tube packaged in the photoelectric isolator, and the reverse protection module is connected to the photosensitive semiconductor tube; the reverse protection module is provided with a reverse protection circuit, and the reverse protection circuit includes a third current limiting resistor for limiting the current flowing through the emitter of the photosensitive semiconductor tube, and the third current limiting resistor is connected to the emitter of the photosensitive semiconductor tube. If the current flowing through the photosensitive semiconductor tube exceeds the normal current value of the photosensitive semiconductor tube, the third current limiting resistor limits the current flowing through the photosensitive semiconductor tube to the normal current value of the photosensitive semiconductor tube; due to the current limiting effect of the third current limiting resistor, the current flowing through the photosensitive semiconductor tube is prevented from being too large and breaking down the photosensitive semiconductor tube, thereby further protecting the photoelectric isolator. Since the cost of the third current limiting resistor is extremely cheap, it is negligible compared to the cost of the photoelectric isolator, and it can be ignored compared to imported photoelectric isolation equipment or devices. Even if it is destroyed due to overcurrent, it only needs regular maintenance or updating.

[0011] Preferably, the reverse protection circuit also includes a second diode, and the two ends of the second diode are respectively connected to the collector of the photosensitive semiconductor tube and the third current limiting resistor. Among them, the third current limiting resistor is 1KΩ; if the instantaneous voltage value generated by the terminal voltage between the collector and the emitter of the photosensitive semiconductor tube exceeds the normal voltage value of the photosensitive semiconductor tube, the second diode is broken down, thereby breaking down the second diode to disconnect the circuit between the photosensitive semiconductor tube and the post-stage test equipment, thereby protecting the photosensitive semiconductor tube from being broken down by breaking down the second diode, thereby protecting the photoelectric isolator from being damaged. Since most of the cost of this device is concentrated on the photoelectric isolator element, even if the second diode is broken down and needs to be replaced with a new second diode, the second diode is much cheaper than the photoelectric isolator and the second diode is cheap. Replacing a second diode is less than 60 yuan, and it is very convenient to replace the second diode. Therefore, compared with imported equipment or devices of the same type, it has huge cost advantages and use value.

[0012] Preferably, the reverse protection circuit also includes a fourth current limiting resistor for limiting the current flowing through the second diode, and the fourth current limiting resistor is connected in series between the second diode and the third current limiting resistor. The fourth current limiting resistor is 1KΩ; if the current flowing through the second diode exceeds the normal current value of the second diode, the fourth current limiting resistor limits the current flowing through the second diode to the normal current value of the second diode; due to the current limiting effect of the fourth current limiting resistor, the current flowing through the second diode is prevented from being too large and breaking down the second diode, thereby protecting the second diode, and further protecting the photoelectric isolator. Since the fourth current limiting resistor is low in cost, it is negligible compared to the cost of the second diode, and can be ignored compared to imported photoelectric isolation equipment or devices. Even if it is destroyed due to overcurrent, it only needs regular maintenance or updating.

[0013] Preferably, the resistor voltage divider module is provided with a resistor voltage divider circuit, which includes a sampling resistor for sampling the port voltage of the sample under test, a voltage divider resistor for dividing the voltage taken by the sampling resistor, the sampling resistor and the voltage divider resistor are connected in series, the two ends of the voltage divider resistor are respectively connected to the anode and cathode of the light-emitting diode, and the first current limiting resistor is connected in series between the voltage divider resistor and the anode of the light-emitting diode. Among them, 5 sampling resistors are connected in series to form a sampling circuit, each sampling resistor is 33K'Ω, and the voltage divider resistor is 3K'Ω.

[0014] As a preference, it also includes a current regulating module and a voltage regulating module respectively connected to the port of the sample under test, wherein the current regulating module includes a front-stage impedance and a rear-stage impedance for regulating the current flowing through the sample under test, a front-stage inductor connected in series with the front-stage impedance and used to adjust the time constant of the front-stage impedance, and a rear-stage inductor connected in series with the rear-stage impedance and used to adjust the time constant of the rear-stage impedance, wherein the front-stage impedance, the front-stage inductor, the rear-stage impedance, and the rear-stage inductor are all connected to the port of the sample under test; and the voltage regulating module includes a varistor for limiting the port voltage at the input end of the sample under test, and the varistor is connected to the port of the sample under test. Due to the presence of the varistor, when the port voltage of the sample under test exceeds 2500V, the varistor limits the voltage to 2500V, thereby making the port voltage at the input end of the sample under test stably maintained at 2500V, thereby ensuring the stability of the input voltage of the photoelectric isolation module and the resistor voltage divider module.

[0015] The present invention has significant technical effects due to the adoption of the above technical scheme: a photoelectric isolator is adopted, and a dual protection mechanism is formed by an overcurrent and overvoltage protection circuit and a reverse protection circuit to realize the protection function in the overvoltage process of short-circuit testing, which greatly reduces the cost and improves the utilization efficiency; the device fills the gap in domestic technology research and development, and compared with the same type of imported equipment from abroad, the direct economic benefits it can generate exceed 280,000 yuan, and the cost-effectiveness ratio reaches 4666.67 times. It has the obvious advantages of low cost and high efficiency, and has extremely high market promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a principle block diagram of an embodiment of an overvoltage photoelectric isolation protection device based on short-circuit testing of the present invention.

[0017] Figure 2 It is a principle block diagram of an embodiment of the photoelectric isolation module of the present invention.

[0018] Figure 3 FIG. 4 is a circuit diagram of an embodiment of a photoelectric isolation module of the present invention.

[0019] Figure 4 This is a connection diagram for a two-pole switch DC normal operation performance test based on a short-circuit test overvoltage photoelectric isolation protection device embodiment of the present invention.

[0020] Figure 5 This is a connection diagram for a two-pole switch DC short-circuit test based on an embodiment of the short-circuit test overvoltage photoelectric isolation protection device of the present invention.

[0021] Figure 6 This is a connection diagram for a single-pole switch DC short-circuit test based on an embodiment of the short-circuit test overvoltage photoelectric isolation protection device of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0023] Based on short circuit testing overvoltage optoelectronic isolation protection devices, such as Figure 1-6 As shown, it includes a photoelectric isolation module 1, which includes a resistor voltage divider module 11 for sampling the port voltage of the sample 2 under test and dividing the sampled voltage, a photoelectric isolator 13 for optically coupling the electrical signal output by the resistor voltage divider module 11, an overcurrent and overvoltage protection module 12 for overcurrent and overvoltage protection of a light-emitting diode 131 encapsulated in the photoelectric isolator 13, and a power supply module 15 connected to the photoelectric isolator 13 and supplying power to the photoelectric isolator 13. The resistor voltage divider module 11, the overcurrent and overvoltage protection module 12, and the photoelectric isolator 13 are connected in sequence.

[0024] In this embodiment, the overcurrent and overvoltage protection module 12 is provided with an overcurrent and overvoltage protection circuit 120, which includes a first diode 1201, the cathode of the first diode 1201 is respectively connected to the anode of the resistance divider module 11 and the light-emitting diode 131, and the anode of the first diode 1201 is connected to the cathode of the light-emitting diode 131.

[0025] In this embodiment, the overcurrent and overvoltage protection circuit 120 further includes a first current limiting resistor 1204 for limiting the current flowing into the light emitting diode 131 . The first current limiting resistor 1204 is connected in series between the cathode of the first diode 1201 and the anode of the light emitting diode 131 .

[0026] In this embodiment, the overcurrent and overvoltage protection circuit 120 further includes an overcurrent and overvoltage protection resistor for limiting the current flowing through the first diode 1201 , and the overcurrent and overvoltage protection resistor is connected in series with the anode of the first diode 1201 .

[0027] In this embodiment, the overcurrent and overvoltage protection resistor includes an adjustable resistor 1202 which is connected in series with the anode of the first diode 1201 and can adjust the size of the resistor 1202, and a second current limiting resistor 1203 which is connected in series with the adjustable resistor 1202. The current flowing through the first diode 1201 is adjusted by connecting the adjustable resistor 1202 and the second current limiting resistor 1203 in series, thereby limiting the current flowing through the first diode 1201.

[0028] In this embodiment, a reverse protection module 14 is also included for overcurrent protection of a photosensitive semiconductor tube 132 encapsulated in the optoelectronic isolator 13, and the reverse protection module 14 is connected to the photosensitive semiconductor tube 132; the reverse protection module 14 is provided with a reverse protection circuit 140, and the reverse protection circuit 140 includes a third current limiting resistor 1403 for limiting the current flowing through the emitter of the photosensitive semiconductor tube 132, and the third current limiting resistor 1403 is connected to the emitter of the photosensitive semiconductor tube 132.

[0029] In this embodiment, the reverse protection circuit 140 further includes a second diode 1401 , and two ends of the second diode 1401 are connected to the collector of the photosensitive semiconductor tube 132 and a third current limiting resistor 1403 , respectively.

[0030] In this embodiment, the reverse protection circuit 140 further includes a fourth current limiting resistor 1402 for limiting the current flowing through the second diode 1401 . The fourth current limiting resistor 1402 is connected in series between the second diode 1401 and the third current limiting resistor 1403 .

[0031] In this embodiment, the resistor voltage divider module 11 is provided with a resistor voltage divider circuit 110, and the resistor voltage divider circuit 110 includes a sampling resistor 1101 for sampling the port voltage of the sample 2 under test, and a voltage divider resistor 1102 for dividing the voltage sampled by the sampling resistor 1101. The sampling resistor 1101 is connected in series with the voltage divider resistor 1102, and the two ends of the voltage divider resistor 1102 are respectively connected to the anode and cathode of the light-emitting diode 131, and the first current limiting resistor 1204 is connected in series between the voltage divider resistor 1102 and the anode of the light-emitting diode 131.

[0032] In this embodiment, it also includes a current regulating module 3 and a voltage regulating module 4 respectively connected to the ports of the sample under test 2. The current regulating module 3 includes a front-stage impedance 31 and a rear-stage impedance 33 for adjusting the current flowing through the sample under test 2, a front-stage inductor 32 connected in series with the front-stage impedance 31 and used to adjust the time constant of the front-stage impedance 31, and a rear-stage inductor 34 connected in series with the rear-stage impedance 33 and used to adjust the time constant of the rear-stage impedance 33. The front-stage impedance 31, the front-stage inductor 32, the rear-stage impedance 33, and the rear-stage inductor 34 are all connected to the port of the sample under test 2; the voltage regulating module 4 includes a varistor 40 for limiting the port voltage of the input end of the sample under test 2, and the varistor 40 is connected to the port of the sample under test 2.

[0033] In conclusion, the above is only a preferred embodiment of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the patent of the present invention.

Claims

1. Based on short circuit test overvoltage photoelectric isolation protection device, it is characterized by: The photoelectric isolation module (1) comprises a resistor voltage divider module (11) for sampling the voltage of a port of a sample (2) to be tested and dividing the sampled voltage, a photoelectric isolator (13) for performing an optical coupling action on an electrical signal output by the resistor voltage divider module (11), an overcurrent and overvoltage protection module (12) for performing overcurrent and overvoltage protection on a light-emitting diode (131) encapsulated in the photoelectric isolator (13), and a power supply module (15) connected to the photoelectric isolator (13) and supplying power to the photoelectric isolator (13). The resistor voltage divider module (11), the overcurrent and overvoltage protection module (12), and the photoelectric isolator (13) are connected in sequence. The overcurrent and overvoltage protection module (12) is provided with an overcurrent and overvoltage protection circuit (120), the overcurrent and overvoltage protection circuit (120) comprising a first diode (1201), the cathode of the first diode (1201) being respectively connected to the anode of the resistor voltage divider module (11) and the light-emitting diode (131), and the anode of the first diode (1201) being connected to the cathode of the light-emitting diode (131); The overcurrent and overvoltage protection circuit (120) further comprises a first current limiting resistor (1204) for limiting the magnitude of the current flowing into the light emitting diode (131); the first current limiting resistor (1204) is connected in series between the cathode of the first diode (1201) and the anode of the light emitting diode (131); The overcurrent and overvoltage protection circuit (120) further comprises an overcurrent and overvoltage protection resistor for limiting the magnitude of the current flowing through the first diode (1201), and the overcurrent and overvoltage protection resistor is connected in series with the anode of the first diode (1201); The overcurrent and overvoltage protection resistor comprises an adjustable resistor (1202) connected in series with the anode of the first diode (1201) and capable of adjusting the size of the resistor (1202), and a second current limiting resistor (1203) connected in series with the adjustable resistor (1202); the size of the current flowing through the first diode (1201) is adjusted by connecting the adjustable resistor (1202) and the second current limiting resistor (1203) in series, thereby limiting the size of the current flowing through the first diode (1201); It also includes a reverse protection module (14) for overcurrent protection of a photosensitive semiconductor tube (132) packaged in a photoelectric isolator (13), the reverse protection module (14) being connected to the photosensitive semiconductor tube (132); the reverse protection module (14) is provided with a reverse protection circuit (140), the reverse protection circuit (140) including a third current limiting resistor (1403) for limiting the magnitude of a current flowing through the emitter of the photosensitive semiconductor tube (132), the third current limiting resistor (1403) being connected to the emitter of the photosensitive semiconductor tube (132); The reverse protection circuit (140) further comprises a second diode (1401), and two ends of the second diode (1401) are respectively connected to the collector of the photosensitive semiconductor tube (132) and the third current limiting resistor (1403); The reverse protection circuit (140) further comprises a fourth current limiting resistor (1402) for limiting the magnitude of the current flowing through the second diode (1401), and the fourth current limiting resistor (1402) is connected in series between the second diode (1401) and the third current limiting resistor (1403); The resistor voltage divider module (11) is provided with a resistor voltage divider circuit (110), the resistor voltage divider circuit (110) comprising a sampling resistor (1101) for sampling the voltage of the port of the sample (2) under test, and a voltage divider resistor (1102) for dividing the voltage sampled by the sampling resistor (1101), the sampling resistor (1101) and the voltage divider resistor (1102) being connected in series, the two ends of the voltage divider resistor (1102) being respectively connected to the anode and cathode of the light-emitting diode (131), and the first current limiting resistor (1204) being connected in series between the voltage divider resistor (1102) and the anode of the light-emitting diode (131); five sampling resistors (1101) are connected in series to form a sampling circuit, each sampling resistor (1101) is 33KΩ, and the voltage divider resistor (1102) is 3KΩ.

2. The overvoltage photoelectric isolation protection device based on short-circuit test according to claim 1 is characterized in that: The invention also comprises a current regulating module (3) and a voltage regulating module (4) respectively connected to the ports of the sample under test (2). The current regulating module (3) comprises a front-stage impedance (31) and a rear-stage impedance (33) for regulating the current flowing through the sample under test (2), a front-stage inductor (32) connected in series with the front-stage impedance (31) and used to adjust the time constant of the front-stage impedance (31), and a rear-stage inductor (34) connected in series with the rear-stage impedance (33) and used to adjust the time constant of the rear-stage impedance (33). The front-stage impedance (31), the front-stage inductor (32), the rear-stage impedance (33), and the rear-stage inductor (34) are all connected to the port of the sample under test (2). The voltage regulating module (4) comprises a varistor (40) for limiting the port voltage at the input end of the sample under test (2). The varistor (40) is connected to the port of the sample under test (2).

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