A test platform for electrical fire protection current limiting protectors based on phase recognition

Abstract

The present invention discloses a test platform for electrical fire-proof current-limiting protectors based on phase identification, which belongs to the technical field of fire-proof current-limiting protector test, includes a short-circuit test unit, a load test unit and a self-protection unit, and establishes a technical index system for short-circuit test and load test of electrical fire-proof current-limiting protectors. The short-circuit function and load function of the electrical fire-proof current-limiting protector are tested through the test module, and the load operation is automatically stopped after the self-protection condition is met. The present invention proposes a function of injecting a short-circuit signal test based on a specified phase, which ensures the consistency of the test results of the electrical fire-proof current-limiting protector product; standardizes the performance detection requirements and test methods of the product, ensures the credibility of the test results, guarantees the inspection capability of the electrical fire-proof current-limiting protector product, and further improves the performance of the electrical fire-proof current-limiting protector product.

Description

Technical Field

[0001] The invention relates to the technical field of fire-proof current-limiting protector testing, and in particular to an electrical fire-proof current-limiting protector testing platform based on phase recognition. Background Art

[0002] The electrical fire-proof current-limiting protector can effectively overcome the shortcomings of traditional circuit breakers, air switches and monitoring equipment, such as large short-circuit current, long short-circuit current cut-off time, large arc sparks generated during short-circuit, and short service life, and achieve μs-level current limiting. According to product standard requirements, when a short-circuit fault occurs in the distribution line, the electrical fire-proof current-limiting protector should be able to quickly limit the short-circuit current within 150μs to achieve arc extinguishing protection, thereby significantly reducing electrical fire accidents and ensuring the safety of personnel and property in the use site.

[0003] Application number CN201721433977.8 is the test circuit principle scheme of the electrical fire-proof current-limiting protector. The national standard GB 14287.6 "Electrical Fire Monitoring System Part 6 Electrical Fire-proof Current-limiting Protector" for electrical fire-proof current-limiting protector products is being submitted for approval. At present, the test methods adopted by product manufacturers and scientific research institutes are based on the draft of the standard. The standard requires the product to be tested for short-circuit performance. The method of "instant injection" of short-circuit signals is adopted. After the line is short-circuited, the timing starts to test the protection time of the electrical fire-proof current-limiting protector. There is a problem with this method. When the mains input signal changes in the form of a sine wave, when the short-circuit signal is injected, the sine wave phase of the current is different, and the current surges to the short-circuit protection current and the time for the electrical fire-proof current-limiting protector to act are different. The protection action time of the electrical fire-proof current-limiting protector measured by the "instant injection" method is difficult to reproduce, and the consistency between the results of multiple tests is poor. There are uncontrollable factors in the judgment of the test results. The traditional test method for electrical fire-proof current-limiting protectors cannot accurately achieve various short-circuit injection conditions in product testing, and the results are somewhat random, with poor reproducibility of product inspection results. At the same time, the existing test method has a single current-limiting protection test method in product overload performance testing, and only tests the product when the current reaches 120% and 80%. The overload performance test does not conduct targeted tests on the complexity of the power distribution system and the time when the product should perform current-limiting protection under different overload currents. Summary of the invention

[0004] In view of the above-mentioned shortcomings and deficiencies, the present invention provides an electrical fire-proof current-limiting protector test device and method based on phase recognition, which is used for short-circuit and overload performance testing of electrical fire-proof current-limiting protector products, and is applied to the inspection of electrical fire-proof current-limiting protector products, standardizes product performance testing requirements and test methods, ensures the credibility of the test results, guarantees the inspection capability of electrical fire-proof current-limiting protector products, further improves the performance of electrical fire-proof current-limiting protector products, and solves the technical problems in the existing electrical fire-proof current-limiting protector detection technology that the short-circuit signal cannot be injected in the specified phase, the test results are random, and the reproducibility is poor.

[0005] In order to achieve the above-mentioned purpose, the main technical scheme adopted by the present invention includes: a test module, an operating table and an oscilloscope. The electrical fire-proof current-limiting protector to be tested is connected to the test platform in series. After the electrical fire-proof current-limiting protector is connected to the load, a protected circuit is formed. The external voltage test terminal and the external current test terminal of the test platform are electrically connected to the oscilloscope. The test process of the electrical fire-proof current-limiting protector is controlled by the operating table; the test module includes a short-circuit test unit, a load test unit and a self-protection unit, and a technical indicator system for short-circuit test and load test of the electrical fire-proof current-limiting protector is established. The short-circuit function and load function of the electrical fire-proof current-limiting protector are tested through the test module, and the load operation is automatically stopped after the self-protection conditions are met.

[0006] The short-circuit test unit presets the designated phase of the injected short-circuit signal, the short-circuit protection current value, the short-circuit delay injection time and the self-protection condition. After the test starts, within the set short-circuit delay injection time, the short-circuit test unit calculates the short-circuit time when the current waveform sine wave is 0° phase angle, divides the 20ms / 50Hz mains current waveform into 360 equal parts, and obtains the time point of the k° phase as the 0° phase time point + (k÷360×20) ms. After the short-circuit delay injection time, when the current signal with a phase of k° is read, the short-circuit signal is immediately injected to realize the function of injecting the short-circuit signal with the designated phase, wherein k is an integer between 0 and 360.

[0007] The technical indicator system of the short-circuit test of the electrical fire-proof current-limiting protector includes a delayed injection time of 3s to 60s, a current waveform of the electrical fire-proof current-limiting protector is a sine wave of 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315°, and when a short circuit occurs at any typical phase angle, the short-circuit protection action instantaneous current of the electrical fire-proof current-limiting protector is not less than 5 times the rated working current, the absolute value of the difference between the short-circuit protection action instantaneous current of the electrical fire-proof current-limiting protector and the short-circuit protection current setting value is not greater than 10% of the short-circuit protection current setting value, and the current limiting protection time of the electrical fire-proof current-limiting protector is not greater than 150μs.

[0008] The load testing unit presets the load current, transformer output voltage, load type, inputs the rated working current load starting time, and tests the over-starting current protection function, high-power overload protection function, low-power overload protection function, and voltage fluctuation function of the electrical fire-proof current-limiting protector through the technical indicator system of the load test of the electrical fire-proof current-limiting protector, and records the test data and transmits it to the oscilloscope for display.

[0009] The technical indicator system of the load test of the electrical fire-proof current-limiting protector includes that when the instantaneous current value of the protected circuit reaches 5 times the rated working current value of the protector, the electrical fire-proof current-limiting protector should trigger the current-limiting protection action within 0.1s; when the effective value of the current of the protected circuit reaches 255% of the rated working current value of the protector, and the maximum instantaneous current does not exceed 5 times the rated working current value, the electrical fire-proof current-limiting protector should trigger the current-limiting protection action within 3s to 60s; when the effective value of the current of the protected circuit reaches 145% of the rated current value of the protector, and is less than 255% of the rated working current value, the electrical fire-proof current-limiting protector should trigger the current-limiting protection action within 30min to 1h; when the current value of the protected circuit is not greater than 113% of the rated working current of the protector, the protector should not trigger the current-limiting protection action within 1h.

[0010] The self-protection unit sets the platform short-circuit self-protection time to 100ms, and the self-protection unit sets the platform load self-protection time. When the load current is greater than 255% of the rated working current, the load self-protection time is 60s; when the load current is between 145% and 255% of the rated working current, the load self-protection time is 1h; when the load current is less than 145% of the rated working current, the load self-protection time is 1h30min; when a short circuit or load test is performed, if the test exceeds the platform self-protection time, the platform self-protection is started, and the short circuit is automatically released while the load operation is stopped.

[0011] The present invention has the following beneficial effects and advantages:

[0012] The electrical fire-proof current-limiting protector test device based on phase recognition of the present invention aims at the problem that the short-circuit test in the traditional electrical fire-proof current-limiting protector test process is difficult to ensure the consistency of the test results, and the overload test index has no differentiation between the test results of different overload conditions. It proposes a function of injecting short-circuit signal test based on the specified phase, which ensures the consistency of the test results of the electrical fire-proof current-limiting protector product. It is used for short-circuit and overload performance testing of electrical fire-proof current-limiting protector products, and is applied to the inspection of electrical fire-proof current-limiting protector products, standardizing the performance testing requirements and test methods of the products, ensuring the credibility of the inspection results, guaranteeing the inspection capability of electrical fire-proof current-limiting protector products, and further improving the performance of electrical fire-proof current-limiting protector products. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the test device of the present invention;

[0014] Figure 2 is a flow chart of the test method of the present invention;

[0015] Figure 3 It is a general diagram of current changes when a short-circuit signal is injected at a current phase of 90° in the short-circuit test of the present invention;

[0016] Figure 4 A detailed diagram of current limiting protection for injecting a short-circuit signal at 90° of the current phase in the short-circuit test of the present invention;

[0017] Figure 5 This is a test result diagram of the present invention when a load test is performed at 145% of the rated load current;

[0018] Figure 6 This is a test result diagram of the present invention when a load test is performed at 255% of the rated load current;

[0019] Figure 7 This is a test result diagram of the present invention when a load test is performed at 500% of the rated load current;

[0020] Figure 8 This is the short-circuit protection time diagram for six random phase tests;

[0021] Fig. 9 The short-circuit protection time diagram is tested by injecting short-circuit signals at 45° of the specified current phase for six times.

[0022] in Figure 1 In the figure, 1: cabinet; 2: operating table; 3: confirmation button; 4: start button; 5: LCD display; 6: operation status indicator light; 7: equipment power-on switch; 8: power-on switch of the distribution line of the electrical fire-proof current-limiting protector; 9: oscilloscope; 10: external current test terminal; 11: external voltage test terminal; 12: wireless communication module with the load; 13: electrical fire-proof current-limiting protector to be tested; 14: built-in transformer; 15: external load voltage output terminal; 16: laser short-circuit switch; 17: operating table lifting hydraulic rod; 18: emergency stop button. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings. Figure 1~2As shown, the present invention is a test platform for electrical fire-proof current-limiting protectors based on phase recognition, comprising: a test module, an operating table and an oscilloscope. The electrical fire-proof current-limiting protector to be tested is connected to the test platform in series, and a protected circuit is formed after the protector is connected to the load. The external voltage test terminal and the external current test terminal of the test device body are electrically connected to the oscilloscope, and the test process of the electrical fire-proof current-limiting protector is controlled by the operating table; the test module comprises a short-circuit test unit, a load test unit and a self-protection unit, and a technical indicator system for short-circuit test and load test of the electrical fire-proof current-limiting protector is established, and the short-circuit function and load function of the electrical fire-proof current-limiting protector are tested by the test module, and the load operation is automatically stopped after the self-protection condition is met.

[0024] 1: Cabinet: The outer shell of the test device, made of metal material;

[0025] 2: Operation table: used to connect the electrical fire-proof current-limiting protector, with the wiring terminals of the electrical fire-proof current-limiting protector built in;

[0026] 3: Confirm button: used to confirm parameters after parameter setting is completed;

[0027] 4: Start button: one-touch start for short circuit and load functions;

[0028] 5: LCD display: Touch screen LCD display, used to set parameters, display measurement results, and control timing devices;

[0029] 6: Operation status indicator: platform operation, stop, function selection and other status;

[0030] 7: Equipment power-on switch;

[0031] 8: Power-on switch for distribution line of electrical fire-proof current-limiting protector: power-on switch for distribution circuit;

[0032] 9: Oscilloscope: Display and record the current and voltage waveforms during the test;

[0033] 10: External current test terminal: used for connecting the oscilloscope current meter pen, built into the cabinet;

[0034] 11: External voltage test terminal: used for connecting the oscilloscope voltage test pen, built into the cabinet;

[0035] 12: Wireless communication module with the load: sends the setting parameters of the load to the external load in the form of wifi;

[0036] 13: Electrical fire-proof current-limiting protector to be tested: sample to be tested;

[0037] 14: Built-in transformer: used to adjust the input voltage of the system and perform tests under different voltage conditions;

[0038] 15: External load voltage output terminal: used to connect external load;

[0039] 16: Laser short-circuit switch: a switch for injecting short-circuit signal, remotely controlled by the start button;

[0040] 17: Operating table lifting hydraulic rod: used to open and close the operating table;

[0041] 18: Emergency stop button: Emergency stop button of the equipment.

[0042] When performing a short-circuit test, first select the short-circuit test function. The short-circuit test unit presets the injection self-protection conditions, the specified phase of the short-circuit signal (0 to 360° arbitrarily set), the short-circuit protection current value, and the short-circuit delay injection time (3s ~ 60s, of which 0 s ~ 1s is used to reconstruct the input mains). After the test starts, after the set delay injection time, the short-circuit test unit obtains the short-circuit time when the current waveform sine wave is 0° phase angle, that is, after setting the delay injection time, Short Circuit During the delayed injection time, 1 second is selected as the calculation interval, 100,000 time points are extracted, and the effective voltage values ​​at these time points are obtained. With a step size of 2000 time points, the average effective voltage values ​​of the 1st, 2001st, ..., 9801st and other 50 time points are calculated, which is recorded as K1. Similarly, the average effective voltage values ​​of the 2nd, 2002nd, ..., 9802nd and other 50 time points are calculated. The maximum, minimum and average voltage values ​​of 2000 time points are obtained. According to the change law of the AC220V AC voltage sinusoidal wave, the 0° phase should be the instantaneous time point when the voltage average value and the voltage value show an upward trend. This time point is defined as the 0° phase time point.

[0043] After calculating the 0° phase time point, divide the 20ms / 50Hz mains current waveform into 360 equal parts. The k° phase time point is (0° phase time point + (k÷360×20)) ms. After the delay, when the current signal with a phase of k° is read, the short-circuit signal is immediately injected to realize the function of injecting the short-circuit signal at the specified phase, where k is an integer between 0 and 360.

[0044] The technical index system for short-circuit testing of electrical fire-proof current-limiting protectors includes: when a short circuit occurs at any phase angle such as 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315°, the short-circuit protection action instantaneous current of the electrical fire-proof current-limiting protector shall not be less than 5 times the rated working current, the absolute value of the difference between the short-circuit protection action instantaneous current of the electrical fire-proof current-limiting protector and the short-circuit protection current setting value shall not be greater than 10% of the short-circuit protection current setting value, and the current limiting protection time of the electrical fire-proof current-limiting protector shall not be greater than 150μs.

[0045] The self-protection unit sets the platform short-circuit self-protection time to 100ms. When a short-circuit test is performed, if the test time exceeds the platform self-protection time, the device will start self-protection, automatically release the short circuit and stop the load operation.

[0046] According to the technical indicator system of short-circuit test of electrical fire-proof current-limiting protector, a short-circuit test is performed, and the test data is displayed on an oscilloscope to facilitate subsequent judgment of the short-circuit test result. In this embodiment, a short-circuit test is performed when the current phase is 90°, such as Figure 3~4 The test data displayed by the oscilloscope shown are the overall diagram of current change during short circuit and the detailed diagram of current limiting protection. The current limiting protection time is 59μs.

[0047] When performing a load test, select the load test function. The load test unit presets the load current, transformer output voltage, and load type (resistive, capacitive, inductive). Enter the rated working current load start time. The over-starting current protection function, high-power overload protection function, low-power overload protection function, and voltage fluctuation function of the electrical fire-proof current-limiting protector are tested through the technical indicator system of the load test of the electrical fire-proof current-limiting protector, and the test data is recorded and transmitted to the oscilloscope for display.

[0048] The technical index system of the load test of the electrical fire-proof current-limiting protector includes:

[0049] When the instantaneous current value of the protected circuit reaches 5 times the rated working current value of the protector, the electrical fire-proof current-limiting protector shall trigger the current-limiting protection action within 0.1s;

[0050] When the effective value of the current in the protected circuit reaches 255% of the rated working current of the protector, and the maximum instantaneous current does not exceed 5 times the rated working current, the electrical fire-proof current-limiting protector shall trigger the current-limiting protection action within 3 s to 60 s; at this time, the load self-protection time is 60s. If the test time exceeds 60s, the self-protection of the device will be started, and the short circuit will be automatically released while the load operation will be stopped.

[0051] When the effective value of the current in the protected circuit reaches 145% of the rated current value of the protector and is less than 255% of the rated working current value, the electrical fire-proof current-limiting protector shall trigger the current-limiting protection action within 30 minutes to 1 hour; at this time, the load self-protection time is 1 hour. If the test time exceeds 1 hour, the self-protection device will be started, automatically releasing the short circuit and stopping the load operation.

[0052] When the load current is less than 145% of the rated working current, the load self-protection time is 1h30min; if the test time exceeds 1h30min, the device will start self-protection, automatically release the short circuit and stop the load operation.

[0053] The load test is performed according to the technical index system of the load test of the electrical fire-proof current-limiting protector, and the test data is displayed on the oscilloscope to facilitate the subsequent judgment of the load test results. In this embodiment, Figures 5 to 7 As shown, the tests were carried out at 145%, 255% and 500% of the rated load current respectively. Under different levels of load conditions, the current limiting protection time of the electrical fire-proof current limiting protector will vary according to the current size. The test results show that the invention can meet the performance tests under different load conditions.

[0054] Comparative example: A short-circuit signal is injected into a random phase 6 times through a traditional electrical fire-proof current-limiting protector, and the short-circuit protection time of the electrical fire-proof current-limiting protector is tested each time (e.g. Figure 8 As shown), the invention then injects 6 short-circuit signals at a current phase of 45°, and measures the current limiting protection time of each electrical fire-proof current limiting protector (as shown in FIG. Fig. 9 As shown), Table 1 is the time comparison result of the current limiting protection of the short-circuit signal injected at 45° by six random phases and six specified current phases. Through the comparison in Table 1, it can be obtained that the data measured by the traditional test method has a wide distribution and the uncertainty of the test results is high. The application of the invention can ensure that the test results are basically consistent in the product short-circuit performance test, thereby ensuring the credibility of the test results and better testing the product performance.

[0055] Number of trials Unspecified current phase (μs) Current 45° phase (μs) 1 82 80 2 119 82 3 84 66 4 474 67 5 593 73 6 62 78

[0056] Table 1

Claims

1. An electrical fire protection current limiting protector test platform based on phase recognition, characterized in that: include: A test module, an operating table and an oscilloscope. The electrical fire-proof current-limiting protector to be tested is connected to the test platform in series. The electrical fire-proof current-limiting protector is connected to the load to form a protected circuit. The external voltage test terminal and the external current test terminal of the test platform are electrically connected to the oscilloscope. The test process of the electrical fire-proof current-limiting protector is controlled by the operating table. The test module includes a short-circuit test unit, a load test unit and a self-protection unit, and a technical indicator system for short-circuit test and load test of the electrical fire-proof current-limiting protector is established. The short-circuit function and load function of the electrical fire-proof current-limiting protector are tested through the test module, and the load is automatically stopped when the self-protection conditions are met. Operation; the short-circuit test unit presets the specified phase of the injected short-circuit signal, the short-circuit protection current value, the short-circuit delay injection time and the self-protection condition. After the test starts, within the set short-circuit delay injection time, the short-circuit test unit calculates the short-circuit time when the current waveform sine wave is 0° phase angle, and then divides the 20ms / 50Hz mains current waveform into 360 equal parts, and obtains the time point of the k° phase as the 0° phase time point + (k÷360×20) ms. After the short-circuit delay injection time, when the current signal with a phase of k° is read, the short-circuit signal is immediately injected to realize the function of injecting the short-circuit signal at the specified phase, wherein k is an integer between 0 and 360.

2. The electrical fire protection current limiting protector test platform based on phase identification according to claim 1 is characterized in that: The technical index system of the short-circuit test of the electrical fire-proof current-limiting protector includes a delayed injection time of 3s to 60s, a sinusoidal current waveform of the electrical fire-proof current-limiting protector with a phase angle of 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315°, and when a short circuit occurs, the short-circuit protection action instantaneous current of the electrical fire-proof current-limiting protector is not less than 5 times the rated working current, the absolute value of the difference between the short-circuit protection action instantaneous current of the electrical fire-proof current-limiting protector and the short-circuit protection current setting value is not greater than 10% of the short-circuit protection current setting value, and the current limiting protection time of the electrical fire-proof current-limiting protector is not greater than 150μs.

3. The electrical fire protection current limiting protector test platform based on phase identification according to claim 1 is characterized in that: The load testing unit presets the load current, transformer output voltage, load type, inputs the rated working current load starting time, and tests the over-starting current protection function, high-power overload protection function, low-power overload protection function, and voltage fluctuation function of the electrical fire-proof current-limiting protector through the technical indicator system of the load test of the electrical fire-proof current-limiting protector, and records the test data and transmits it to the oscilloscope for display.

4. The electrical fire protection current limiting protector test platform based on phase identification according to claim 1 is characterized in that: The technical indicator system of the load test of the electrical fire-proof current-limiting protector includes that when the instantaneous current value of the protected circuit reaches 5 times the rated working current value of the protector, the electrical fire-proof current-limiting protector should trigger the current-limiting protection action within 0.1s; when the effective value of the current of the protected circuit reaches 255% of the rated working current value of the protector, and the maximum instantaneous current does not exceed 5 times the rated working current value, the electrical fire-proof current-limiting protector should trigger the current-limiting protection action within 3s to 60s; when the effective value of the current of the protected circuit reaches 145% of the rated current value of the protector, and is less than 255% of the rated working current value, the electrical fire-proof current-limiting protector should trigger the current-limiting protection action within 30min to 1h; when the current value of the protected circuit is not greater than 113% of the rated working current of the protector, the protector should not trigger the current-limiting protection action within 1h.

5. The electrical fire protection current limiting protector test platform based on phase identification according to claim 1 is characterized in that: The self-protection unit sets the platform short-circuit self-protection time to 100ms, and the self-protection unit sets the platform load self-protection time. When the load current is greater than 255% of the rated working current, the load self-protection time is 60s; when the load current is between 145% and 255% of the rated working current, the load self-protection time is 1h; when the load current is less than 145% of the rated working current, the load self-protection time is 1h30min; when a short circuit or load test is performed, if the test exceeds the platform self-protection time, the platform self-protection is started, and the short circuit is automatically released while the load operation is stopped.

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