Current cycle testing device for photovoltaic fuse link

Abstract

A photovoltaic fuse-link current cycle test device comprises a voltage regulating module and a current adjusting module which are connected with a mains supply, the voltage regulating module is used for converting the mains supply into a test voltage with an adjustable range, and the current adjusting module is used for converting the test voltage into a plurality of test currents with different fixed values and outputting the test currents to a test sample. The testing device further comprises a control module, the control module is used for switching to the next testing current after the set holding time of the testing current, and the control module automatically counts on the recorder after the different testing currents pass one round. The beneficial effects of the utility model are that the device achieves the automatic management of the testing process of the photovoltaic fuse link through the introduction of the control module, and remarkably improves the testing efficiency and accuracy. Specifically, the control module automatically switches different test currents according to the preset holding time, so that operation errors and time delay caused by manual intervention are avoided.

Description

Technical Field

[0001] The utility model relates to a testing device, in particular to a current circulation testing device for a photovoltaic fuse. Background Art

[0002] In a photovoltaic system, a fuse, as a key protection component, is used to prevent overcurrent from damaging devices such as solar panels and inverters. The current circulation testing device for a photovoltaic fuse is widely used in R & D laboratories, production quality inspection, and on-site maintenance stages to simulate current fluctuations in actual operation and evaluate the durability, fusing characteristics, and lifespan of the fuse. During use, an operator needs to manually set test parameters, such as current intensity (usually 100% - 150% of the rated current), cycle period (such as 30 seconds on / 30 seconds off), and total number of cycles (up to thousands of times). Subsequently, the test is manually started, and it is observed whether the fuse fails during the cycle through a monitoring instrument, and data such as fusing time or temperature change is manually recorded. The entire process relies on the real-time monitoring of the operator, including adjusting the power output, resetting the test bench, and verifying the results, which is not only time-consuming but also requires professional skill support to ensure the accuracy and repeatability of the test.

[0003] However, the existing technology has significant defects, mainly that the testing device lacks an automatic circulation function and completely relies on manual operation. This results in low testing efficiency, as each cycle requires the operator to manually trigger and monitor, increasing the risk of human errors, such as incorrect parameter settings or monitoring negligence, which affects the reliability of the test data. In addition, the manual dependence limits the continuity and scale of the test, and it is impossible to achieve unattended long-term or multi-sample parallel testing, thus increasing the labor intensity, extending the test cycle, and possibly reducing the accuracy of the fuse performance evaluation due to inconsistent operations. This lack of automation hinders the rapid verification of large-scale photovoltaic systems and increases the production cost and maintenance difficulty. Content of the Utility Model

[0004] Aiming at the deficiencies of the existing technology, the utility model provides a current circulation testing device for a photovoltaic fuse that can perform cyclic testing and recording by itself.

[0005] To achieve the above object, the technical solution of the utility model is as follows: A current circulation testing device for a photovoltaic fuse includes a voltage regulating module and a current adjusting module connected to the mains power. The voltage regulating module is used to convert the mains power into a test voltage with an adjustable range. The current adjusting module is used to convert the test voltage into several different fixed-value test currents and output them to the test sample. It further includes a control module, which is used to switch to the next test current after a set holding time of the test current, and the control module automatically counts on a recorder after a round of different test currents.

[0006] The beneficial effects of the present utility model are as follows: By introducing a control module, the device realizes the automated management of the photovoltaic fuse testing process, significantly improving the testing efficiency and accuracy. Specifically, the control module automatically switches different test currents according to the preset holding time, avoiding operation errors and time delays caused by manual intervention. It is particularly suitable for the testing requirements of various specifications of fuses. For example, fuses with different current ratings can quickly verify their performance through a round of cyclic testing. At the same time, the automatic counting function records data after a round of test currents is completed, facilitating the subsequent analysis of the number of tests and the durability of the fuse, ensuring the reliability and traceability of the test results. This reduces the testing cost and supports continuous operation in a large-scale production environment. As a preferred method, the control module can use a programmable logic controller (PLC) as the core. The PLC monitors the holding time through the built-in timing logic. When the set time is reached, it outputs a signal to drive the switching circuit to change the test current. The counting function is realized through the counter module integrated in the PLC. When all test currents complete a round in sequence, the counter automatically increases the value and stores it in the recorder. This structure realizes unattended operation through electronic logic control, ensuring switching accuracy and counting consistency. In addition, the extended beneficial effects include reducing the risk of test interruption because the automatic process reduces test failures caused by human factors and supports custom test sequences, such as adjusting the holding time or the order of test currents, to meet different international standard requirements.

[0007] Further, the current adjustment module includes several resistor branches with different resistances. The control module includes a PLC and a relay connected to the PLC. The relay is respectively connected to several resistor branches. After the holding time is reached, the PLC switches the resistor branch connected to the fuse to be tested through the relay.

[0008] This technical solution optimizes the current adjustment process through a specific structure, improving the stability and flexibility of testing. The design of the resistance branches allows for the generation of multiple fixed test current values. The resistance value of each branch is precisely matched with the adjustable test voltage range to generate the target test current, ensuring the accuracy of the output current and avoiding test deviations caused by voltage fluctuations. The combination of the PLC and the relay enables fast and reliable current switching. The PLC monitors the time through a logic program and controls the relay action, reducing mechanical wear and response delay, thereby extending the device life. This is particularly applicable to scenarios with frequent current changes in photovoltaic fuse testing, such as simulating current cycles under actual working conditions. As a preferred method, the resistance branches can be designed as a parallel resistance network, where each group of branches consists of high-precision fixed resistors and is gated through a relay as an electronic switch. The working principle of the PLC is as follows: The timing module detects the end of the hold time and outputs a digital signal to the relay coil, causing the relay contacts to switch to the target branch, changing the current path of the fuse under test. This structure is simple and easy to maintain, and can cover a wide range of current requirements through resistance value matching, for example, from low current (such as 1A) to high current (such as 100A), supporting diverse test specifications. The extended beneficial effects also include improving test safety because the resistance branches can limit the maximum current, preventing overloading and damaging the samples, and simplifying device upgrades, such as adding new resistance branches to expand the test capabilities.

[0009] Further, a timer, a start switch, and a counter are provided inside the PLC. The timer is used to set the hold time and output a signal to the PLC after the hold time is reached; the start switch is connected to the counter, and the start switch closes after a round of test currents of several different fixed values pass through the hold time and causes the counter to count.

[0010] This solution integrates key functions within the PLC, enhancing the compactness and reliability of the device. The timer precisely controls the holding time to ensure the stability of each test current phase, avoiding data distortion caused by premature switching; the integration of the start switch and counter simplifies the counting logic, automatically triggering counting when a round of testing is completed, reducing the need for external components and thus lowering the failure rate. This improves the automation level of the testing, especially in high-frequency cyclic testing, enabling efficient recording of multiple rounds of data to support long-term durability assessment. As a preferred method, the timer can use the digital timer module of the PLC, setting the time value through the user interface, and outputting an interrupt signal to the PLC main control unit when the time is up; the start switch is designed as a logic input contact. When all test currents are executed in sequence (such as through the internal status flag of the PLC), the switch closes to activate the counter module, and the counter accumulates the number of rounds and outputs it to the recorder. This structure achieves seamless switching and counting through the cooperation of software and hardware, avoiding human misoperation. Extended beneficial effects include improved test repeatability because the built-in modules reduce environmental interference and support remote monitoring, such as exporting data through the PLC communication interface.

[0011] Further, the start switch is a switching switch in the relay used to control the switching of a certain group of resistance branches.

[0012] This solution simplifies the device structure, reduces costs and complexity by reusing the relay switching switch as the start switch. The start switch is directly integrated in the relay without the need for additional independent components, reducing connection points and potential failure sources. At the same time, it ensures that the counting trigger is synchronized with the current switching, improving the accuracy and efficiency of the testing. This is especially suitable for compact test equipment, saving space and facilitating maintenance. As a preferred method, the relay switching switch can be designed as a dual-function contact, closing the start circuit while switching the resistance branch; when the relay operates to select a new branch, the change in its contact state directly serves as the start signal to drive the counter to count, achieving automatic detection at the end of a round of testing. This structure ensures that counting occurs only after a complete cycle through mechanical-electrical linkage, avoiding miscounting. Extended beneficial effects include enhanced system response speed because the signal transmission links are reduced, and improved compatibility, suitable for standardized designs of different relays.

[0013] Further, it also includes a display panel. There are indicator lights corresponding to the number of switching switches in the relay used to control several groups of resistance branches on the display panel, and the switching switch in the relay used to control a certain group of resistance branches is connected to the indicator light.

[0014] This solution enhances the intuitiveness and operability of the device by adding a display panel and indicator lights. The indicator lights display the status of the currently activated resistance branch in real time, helping the operator quickly identify the test current value, reducing the monitoring difficulty and misjudgment; the display panel presents information centrally, facilitating on-site debugging and fault troubleshooting, and improving the test efficiency. This is especially applicable to multi-batch test environments, ensuring the transparency and controllability of the test process. As a preferred method, the indicator lights can be an LED array, with each LED corresponding to a relay switching switch. When the relay closes a specific branch, its control signal simultaneously lights up the corresponding LED; the display panel is integrated into the device housing and is connected to the relay output terminal through a simple circuit. The working principle is that the relay action drives the LED to conduct and emit light. This structure is lightweight and reliable, providing instant visual feedback. Extended beneficial effects include enhanced safety, such as the indicator lights flashing and alarming in case of abnormal current, and supporting training purposes, making it easy for new operators to get started.

[0015] Furthermore, it also includes a sampling module. The sampling module includes a recorder and current sensors corresponding to the number settings of the test current. Several current sensors are connected to the same recorder and output waveforms on the recorder.

[0016] This solution realizes the real-time collection and analysis of test data through the sampling module, enhancing the comprehensiveness and diagnostic ability of the test. The current sensors monitor the real-time values of each test current, and the recorder summarizes the waveform data, facilitating the observation of the response characteristics of the fuse, such as overcurrent or failure modes; the output waveforms support offline analysis, helping to identify potential defects and improving the scientific nature of the test. This is especially applicable to R & D and quality control scenarios, providing detailed performance reports. As a preferred method, the current sensors can be non-contact Hall effect sensors, installed in the test circuit to detect current changes and convert them into voltage signals; the recorder is a multi-channel data collector, receiving all sensor signals and outputting waveform diagrams to the display device through ADC conversion. This structure ensures data synchronization through parallel processing, avoiding signal interference. Extended beneficial effects include improving the test accuracy because waveform analysis can capture transient events, and supporting data export, such as for generating test reports. Description of the Drawings

[0017] Figure 1 It is the circuit schematic diagram of the control module in the embodiment of the present utility model;

[0018] Figure 2 It is the circuit schematic diagram of the voltage regulation module and current adjustment module in the embodiment of the present utility model;

[0019] Figure 3 It is the circuit schematic diagram of the counter in the embodiment of the present utility model;

[0020] Figure 4 It is the circuit schematic diagram of the timer in the embodiment of the present utility model;

[0021] Figure 5 Schematic diagram of the sampling module according to an embodiment of the present utility model;

[0022] Figure 6 Front view of the display panel according to an embodiment of the present utility model. Specific implementation manners

[0023] A current circulation test device for a photovoltaic fuse according to an embodiment of the present utility model is as Figure 1-6 shown: It includes a voltage regulation module 1, a current adjustment module 2, a control module 3, a display panel 4 and a sampling module 5. The voltage regulation module 1 is connected to the mains power supply and is used to convert the mains power supply into a test voltage with an adjustable range. Its implementation manner can refer to an adjustable transformer or an electronic voltage regulator in the prior art, and the required output voltage value is adjusted manually or automatically. The current adjustment module 2 is connected to the output end of the voltage regulation module 1 and is used to convert the test voltage into several different fixed-value test currents and output them to the test sample. Specifically, it includes several groups of resistor branches 21 with different resistance values. Each group of resistor branches 21 sets a fixed test current value by changing the resistance value. For example, different current gears are realized through precision resistors. The control module 3 is connected to the current adjustment module 2 and is used to automatically switch to the next test current after a set holding time of the test current, and automatically count on a recorder after all test currents have passed through one round. The control module 3 includes a PLC 31 and a relay 32 connected to the PLC 31. The relay 32 is respectively connected to several groups of resistor branches 21. The PLC 31 changes the connected resistor branch 21 by controlling the on / off of the relay 32, so as to change the current output to the test sample. A timer 311, a start switch 312 and a counter 313 are arranged in the PLC 31. The timer 311 is used to set the holding time of the test current and output a switching signal to the PLC 31 after reaching the holding time. The start switch 312 is connected to the counter 313. The start switch 312 closes and triggers the counter 313 to perform a counting operation after several different fixed-value test currents sequentially pass through their respective holding times to complete one round of testing. The start switch 312 is a switching switch in the relay 32 for controlling the switching of a certain group of resistor branches 21, and the start switch 312 acts synchronously when this group of resistor branches 21 is activated.

[0024] The display panel 4 is connected to the relay 32. An indicator light 41 is provided thereon corresponding to the number of switching switches of the relay 32 for controlling several groups of resistance branches 21. The switching switch of the relay 32 for controlling a certain group of resistance branches 21 is connected to the corresponding indicator light 41. When switching to a certain group of resistance branches 21, the corresponding indicator light 41 lights up to visually display the current test current range. The sampling module 5 includes a recorder 51 and a current sensor 52 set corresponding to the number of test currents. Several current sensors 52 are respectively connected to the output end of the resistance branch 21 and the input end of the recorder 51. The current sensor 52 collects the test current signal and outputs a waveform diagram through the recorder 51, facilitating real-time monitoring and analysis of the test process.

[0025] The working principle of the device is as follows: First, the mains power is input into the voltage regulating module 1 and then converted into an adjustable test voltage and output to the current adjusting module 2; the current adjusting module 2 converts the voltage into a fixed-value test current according to the selected resistance branch 21 and applies it to the test sample; after the PLC 31 of the control module 3 is started, the timer 311 starts timing the set holding time. After reaching the time, the PLC 31 switches to the next resistance branch 21 through the relay 32 to change the test current; when all test current ranges complete a round of tests in sequence, the start switch 312 closes to trigger the counter 313 to automatically count once; at the same time, the indicator light 41 on the display panel 4 lights up the corresponding indicator light 41 according to the currently activated resistance branch 21; the current sensor 52 of the sampling module 5 collects the test current signal in real time and outputs a waveform for observation and recording; the whole process loops until the preset test times are reached, realizing the automatic current cycle test of the photovoltaic fuse.

[0026] The above embodiments are only one of the preferred specific embodiments of the present invention. The common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. A current circulation test device for a photovoltaic fuse body, comprising a voltage regulating module and a current adjusting module connected to the mains power supply. The voltage regulating module is used to convert the mains power supply into a test voltage with an adjustable range, and the current adjusting module is used to convert the test voltage into several different fixed-value test currents and output them to a test sample. It is characterized in that: It further includes a control module which is used to switch to the next test current after a set holding time of the test current, and the control module automatically counts on a recorder after a round of different test currents.

2. The photovoltaic fuse current circulation test device according to claim 1, characterized in that: The current adjustment module includes several resistor branches with different resistance values. The control module includes a PLC and a relay connected to the PLC. The relay is respectively connected to several resistor branches, and the PLC switches the resistor branch connected to the fuse to be tested through the relay after reaching the holding time.

3. The photovoltaic fuse current cycle test device according to claim 2, characterized in that: A timer, a start switch and a counter are arranged in the PLC. The timer is used to set the holding time and output a signal to the PLC after reaching the holding time; the start switch is connected to the counter, and the start switch closes after a round of several different fixed-value test currents pass through the holding time and makes the counter count.

4. The photovoltaic fuse current circulation test device according to claim 3, characterized in that: The start switch is a switching switch in the relay used to control the switching of a certain resistor branch.

5. The photovoltaic fuse current circulation test device according to claim 2, characterized in that: It further includes a display panel. Indicator lights are arranged on the display panel corresponding to the number of switching switches of the relay used to control several resistor branches, and the switching switch of the relay used to control a certain resistor branch is connected to the indicator light.

6. The photovoltaic fuse current circulation test device according to claim 1, characterized in that: It further includes a sampling module. The sampling module includes a recorder and current sensors set corresponding to the number of test currents. Several current sensors are connected to the same recorder and output waveforms on the recorder.

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