A test device for AC / DC decoupling network of photovoltaic inverter
By employing multi-stage filtering and decoupling technology in the AC/DC decoupling network test device for photovoltaic inverters, the problem that existing devices cannot accurately simulate real working conditions has been solved, achieving high-precision testing and power system stability, and ensuring the stable operation of the photovoltaic power generation system.
Patent Information
- Application Number
- CN202522381958.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-10
- Publication Date
- 2026-11-06
- Estimated Expiration
- 2035-11-10
AI Technical Summary
Existing AC/DC decoupling network test equipment cannot accurately simulate the real operating conditions of photovoltaic inverters, resulting in inaccurate lightning protection performance assessments and an inability to effectively isolate high-frequency interference, affecting the accuracy and reliability of test data and potentially causing power outages or damage to the power supply system.
By employing multi-stage filtering and decoupling technology, and by setting decoupling filter inductors and protection resistors in the power frequency circuit, combined with variable resistors and overvoltage protection devices, the system accurately simulates real operating conditions, isolates high-frequency interference, reduces voltage and current fluctuations, and ensures the stability of the power supply system.
It significantly improves testing accuracy and reliability, reduces testing errors, ensures comprehensive evaluation of inverter performance, provides reliable assurance for the stable operation of photovoltaic power generation systems, and extends the service life of the testing system.
Smart Images
Figure CN224946109U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of solar power generation technology, and in particular to a test device for the surge and lightning strike performance of a photovoltaic inverter. Background Technology
[0002] Depending on the installation location of the photovoltaic inverter in actual applications, it is necessary to simulate its surge and lightning protection performance under real-world operating conditions. However, existing AC / DC decoupling network test equipment cannot accurately simulate actual operating conditions, making it difficult to comprehensively evaluate the inverter's lightning protection performance. Furthermore, existing equipment has shortcomings in its AC / DC decoupling network design, resulting in the power supply system's inability to effectively isolate high-frequency interference generated during surges, thus affecting the accuracy and reliability of test data. These problems may cause power supply system outages, restarts, or even damage, specifically manifesting as frequent fluctuations in power system voltage and current during the test, making it impossible to stably reproduce test results under real-world conditions, severely restricting the optimization and improvement of photovoltaic inverter lightning protection performance. Summary of the Invention
[0003] The purpose of this invention is to provide a test device for AC / DC decoupling networks of photovoltaic inverters, which can accurately simulate real working conditions, effectively isolate high-frequency interference, and significantly improve test accuracy.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: A test device for AC / DC decoupling networks of a photovoltaic inverter includes a power supply, a test sample, and an inrush current generator. The power supply and the test sample are connected to form a power frequency circuit, and the test sample and the inrush current generator are connected to form an inrush circuit. A decoupling filter inductor and a protection resistor are provided in the power frequency circuit. The decoupling filter inductor is respectively set on the input and output terminals of the test sample. The protection resistor is distributed along with the decoupling filter inductor and is embedded in the terminal where the decoupling filter inductor is connected to the power supply. One end of the protection resistor is connected in parallel with the decoupling filter inductor, and the other end of the protection resistor is grounded.
[0005] Furthermore, the above solution is that the power supply is a DC power supply, and an overvoltage protection device and a variable resistor are also provided in the power frequency circuit. The overvoltage protection device is located at the positive terminal of the power supply, and the variable resistor is distributed along with the decoupling filter inductor and embedded between the decoupling filter inductor and the test object.
[0006] A further improvement in the above scheme is that the power supply is a three-phase AC power supply, and an isolation coil and a switch are introduced into the output terminal of the three-phase AC power supply.
[0007] Furthermore, the overvoltage protection device is composed of multiple high-voltage diodes connected in series.
[0008] This invention employs advanced multi-stage filtering and decoupling technology, which can control voltage fluctuations and current shunting within ±5% during simulated surge lightning strikes, significantly reducing test errors. By optimizing the inductance and resistance values of the AC / DC decoupling network, it accurately simulates real-world operating conditions, effectively isolates high-frequency interference, significantly improves test accuracy, ensures comprehensive evaluation of inverter performance, and provides reliable assurance for the stable operation of photovoltaic power generation systems. The inductive reactance in the AC / DC decoupling network effectively suppresses high-frequency interference and reduces the surge steepness caused by impacts; the protective resistor effectively suppresses the short-circuit current generated by the sample during impulse discharge, ensuring that the voltage and current of the power supply system remain stable and reliable. The positive polarity of the DC decoupling network uses an overvoltage protection device to protect the power supply system, preventing overvoltage generated during impulses from being applied to the power supply internally, thereby avoiding power supply damage.
[0009] This invention has a simple structure, few components, low investment cost, and improves the service life and detection performance of the testing system. Attached Figure Description
[0010] Appendix Figure 1 This is the circuit schematic diagram of the present invention for use in a single-phase DC power supply; Appendix Figure 2 This is the circuit diagram of the present invention for use in a three-phase AC power supply. Detailed Implementation
[0011] The following will further explain the concept, specific structure and technical effects of this utility model in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of this utility model.
[0012] It should be noted that in the description of this utility model, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.
[0013] Figure 1 , 2As shown, this utility model provides an AC / DC decoupling network test device for a photovoltaic inverter, including a power supply 1, a test object 2, and an impulse current generator 3. The test object 2 is a photovoltaic inverter. The power supply 1 and the test object 2 are connected to form a power frequency circuit, and the test object 2 and the impulse current generator 3 are connected to form an impulse circuit. The impulse current generator 3 uses fixed LCR parameters for waveform modulation and outputs a waveform that closely matches the actual lightning strike to the test object 2 for surge lightning strike testing. The impulse current generator 3 is existing technology, and its structure and principle will not be described in detail here. In the power frequency circuit, a decoupling filter inductor 4 and a protection resistor 5 are provided. The decoupling filter inductor 4 is respectively set on the input and output terminals of the test object 2. The protection resistor 5 is distributed along with the decoupling filter inductor 4 and embedded in the terminal where the decoupling filter inductor 4 is connected to the power supply 1. One end of the protection resistor 5 is connected in parallel with the decoupling filter inductor 4, and the other end of the protection resistor 5 is grounded. By implementing multi-stage filtering and decoupling, voltage fluctuations can be controlled within ±5% during simulated surge and lightning strikes, and current shunting can also be controlled within ±5%, significantly reducing test errors. By optimizing the inductance and resistance values of the AC / DC decoupling network, the system accurately simulates real operating conditions, effectively isolates high-frequency interference, significantly improves test accuracy, ensures a comprehensive evaluation of inverter performance, and provides a reliable guarantee for the stable operation of photovoltaic power generation systems.
[0014] Figure 1 As shown, when the power supply 1 in this embodiment is a DC power supply, an overvoltage protection device 6 and a variable resistor 7 are also provided in the power frequency circuit. Preferably, the overvoltage protection device 6 is composed of multiple high-voltage diodes connected in series. The overvoltage protection device 6 is set at the positive terminal of the power supply 1 to effectively defend against overvoltages generated during the impact process, thereby avoiding damage to the internal components of the power supply system and ensuring stable operation of the system. The variable resistor 7 is distributed along with the decoupling filter inductor 4 and is embedded between the decoupling filter inductor 4 and the test object 2. By using an adjustable variable resistor 7, the resistance value is precisely adjusted to simulate the test environment under different operating conditions, thereby further optimizing the lightning protection test performance of the inverter and ensuring the accuracy and consistency of the test data. This innovative design not only significantly improves the adaptability and flexibility of the test device, but also greatly reduces the number of repeated tests caused by test errors, effectively reducing R&D costs. In this embodiment, preferably, the inductance of the decoupling filter inductor 4 is 1.4mH. The positive polarity of the DC decoupling network uses multiple high-voltage diodes to protect the power supply system, preventing overvoltages generated during the impact from being applied to the internal components of the power supply, thereby avoiding power supply damage.
[0015] Figure 2As shown, in this embodiment, when the power supply 1 is a three-phase AC power supply, an isolation coil 8 and a switch 9 are introduced at the output terminal of the three-phase AC power supply. The isolation coil 8 provides isolation protection, improving safety and effectively reducing interference. The isolation coil 8 corresponds to the three-phase distribution of A, B, and C, while the switch 9 is a linkage switch, simultaneously connected to the lines of a, b, c, and n, further enhancing implementation safety. The three-phase decoupling network test device can accurately simulate different load power factor conditions by adjusting the inductance and protection resistor values, comprehensively verifying the inverter's lightning protection performance under various operating conditions. This design effectively improves the reliability and practicality of the test results, providing a solid guarantee for the stable operation of the photovoltaic power generation system.
[0016] This invention features a simple structure, few components, and low investment cost. Employing advanced multi-stage filtering and decoupling technology, it can control voltage fluctuations and current shunting within ±5% during simulated surge lightning strikes, significantly reducing test errors. By optimizing the inductance and resistance values of the AC / DC decoupling network, it accurately simulates real-world operating conditions, effectively isolating high-frequency interference and significantly improving test accuracy. This ensures a comprehensive evaluation of inverter performance and provides reliable assurance for the stable operation of photovoltaic power generation systems. The inductive reactance in the AC / DC decoupling network effectively suppresses high-frequency interference and reduces the surge steepness caused by impacts; the protective resistor effectively suppresses short-circuit current generated during impact discharge, ensuring stable and reliable voltage and current in the power supply system. The positive polarity of the DC decoupling network employs an overvoltage protection device to protect the power supply system, preventing overvoltage generated during impacts from being applied to the power supply internally, thereby avoiding power supply damage and improving the service life and testing performance of the test system.
[0017] The present invention has been described in detail above with reference to the embodiments. It is only for the purpose of illustrating the technical concept and features of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it. Therefore, all equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the protection scope of the present invention.
Claims
1. A test device for AC / DC decoupling network of a photovoltaic inverter, comprising a power supply (1), a test object (2), and an impulse current generator (3), wherein the power supply (1) and the test object (2) are connected to form a power frequency circuit, and the test object (2) and the impulse current generator (3) are connected to form an impulse circuit, characterized in that, In the power frequency circuit, a decoupling filter inductor (4) and a protection resistor (5) are provided. The decoupling filter inductor (4) is respectively set on the input and output terminals of the test object (2). The protection resistor (5) is distributed along with the decoupling filter inductor (4) and embedded in the terminal where the decoupling filter inductor (4) is connected to the power supply (1). One end of the protection resistor (5) is connected in parallel with the decoupling filter inductor (4), and the other end of the protection resistor (5) is grounded.
2. The AC / DC decoupling network test device for a photovoltaic inverter according to claim 1, characterized in that: The power supply (1) is a DC power supply. In the power frequency circuit, there is also an overvoltage protection device (6) and a variable resistor (7). The overvoltage protection device (6) is set at the positive terminal of the power supply (1). The variable resistor (7) is distributed with the decoupling filter inductor (4) and is embedded between the decoupling filter inductor (4) and the test object (2).
3. The AC / DC decoupling network test device for a photovoltaic inverter according to claim 1, characterized in that: The power supply (1) is a three-phase AC power supply, and an isolation coil (8) and a switch (9) are introduced into the output terminal of the three-phase AC power supply.
4. The AC / DC decoupling network test device for a photovoltaic inverter according to claim 2, characterized in that: The overvoltage protection device (6) is composed of multiple high-voltage diodes connected in series.