Photovoltaic panel grounding detection device based on switching power supply

Abstract

The utility model discloses a photovoltaic panel grounding detection device based on a switching power supply. The photovoltaic panel grounding detection device comprises an AC rectification filter circuit, a PFC adjustment module, a power conversion module, a sampling module, an MCU module and a control module. The input end of the AC rectification filter circuit is connected with an external power grid input 220V AC voltage, the output end of the AC rectification filter circuit is connected with the input end of the PFC adjustment module, the output end of the PFC adjustment module is connected with the input end of the power conversion module, and the output end of the power conversion module is connected with a tested assembly frame; the input end of the sampling module is connected with the frame of the tested assembly, and the output end of the sampling module is connected with the MCU module; the input end of the control module is connected with the sampling module, and the output end of the control module is connected with the power conversion module. The utility model provides a photovoltaic panel grounding detection device based on a switching power supply, which can judge whether the conduction of a frame of an assembly is good or not, thereby avoiding safety faults caused by poor contact.

Description

Technical Field

[0001] The utility model relates to a photovoltaic panel grounding detection device based on a switching power supply. Background Art

[0002] At present, in the photovoltaic power generation system, the photovoltaic cell components are installed in the open air through brackets to form a photovoltaic array, and the distribution area is large, so there is a danger of direct and indirect lightning strikes, especially in the summer when thunderstorms are frequent. At the same time, the photovoltaic power generation system is directly connected to related electrical equipment and buildings. If the photovoltaic components are struck by lightning, the related equipment and electrical equipment in the building will also be involved. In order to avoid damage to the photovoltaic power generation system caused by lightning strikes, it is necessary to set up a lightning protection grounding system for protection. The main function of the component frame grounding is lightning protection. The lightning protection grounding conducts lightning into the earth to prevent lightning current from causing electric shock to people or property damage. Therefore, the grounding test of the photovoltaic component is particularly important, mainly to test the size of the on-resistance of the component frame. How to quickly and accurately detect the on-resistance is an urgent problem to be solved in this field. Summary of the invention

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a photovoltaic panel grounding detection device based on a switching power supply, which can determine whether the conduction of the component frame is good, thereby avoiding safety failures caused by poor contact.

[0004] In order to solve the above technical problems, the technical solution of the utility model is:

[0005] A photovoltaic panel grounding detection device based on a switching power supply, comprising an AC rectifier filter circuit, a PFC adjustment module, a power conversion module, a sampling module, an MCU module and a control module;

[0006] The input end of the AC rectifier and filter circuit is connected to the external power grid to input a 220V AC voltage, the output end of the AC rectifier and filter circuit is connected to the input end of the PFC adjustment module, the output end of the PFC adjustment module is connected to the input end of the power conversion module, and the output end of the power conversion module is connected to the frame of the component under test;

[0007] The input end of the sampling module is connected to the frame of the component under test, and the output end of the sampling module is connected to the MCU module;

[0008] The input end of the control module is connected to the sampling module, and the output end of the control module is connected to the power conversion module.

[0009] Furthermore, the control module includes a loop control module and a PWM control module, the input end of the loop control module is connected to the sampling module, the output end of the loop control module is connected to the input end of the PWM control module, and the output end of the PWM control module is connected to the power conversion module.

[0010] Furthermore, a filter module is connected between the output end of the power conversion module and the frame of the component under test.

[0011] Furthermore, it also includes a display module, which is connected to the MCU module.

[0012] By adopting the above technical solution, the utility model can provide control of the control module according to the test parameter requirements, generate a constant excitation current at the output end and connect it to the frame of the component under test. Then the sampling module samples the voltage and current, and the MCU module calculates the corresponding on-resistance value to determine whether the component frame is conductive, and the detection result is fast and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a principle block diagram of a photovoltaic panel grounding detection device based on a switching power supply of the utility model;

[0014] Figure 2 The circuit schematic diagram of the AC rectifier filter circuit and the PFC adjustment module of the utility model;

[0015] Figure 3 It is a circuit schematic diagram of the power conversion module, filtering module and sampling module of the utility model;

[0016] Figure 4 This is a circuit schematic diagram of the loop control module of the utility model;

[0017] Figure 5 This is a circuit schematic diagram of the PWM control module of the utility model. DETAILED DESCRIPTION

[0018] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0019] like Figure 1 As shown, this embodiment provides a photovoltaic panel grounding detection device based on a switching power supply, which includes an AC rectifier and filter circuit, a PFC adjustment module, a power conversion module, a filter module, a sampling module, an MCU module, a control module and a display module.

[0020] The input end of the AC rectifier filter circuit is connected to the external power grid to input 220V AC voltage, the output end of the AC rectifier filter circuit is connected to the input end of the PFC adjustment module, the output end of the PFC adjustment module is connected to the input end of the power conversion module, and the output end of the power conversion module is connected to the frame of the component under test through the filter module;

[0021] The input end of the sampling module is connected to the frame of the component under test, and the output end of the sampling module is connected to the MCU module;

[0022] The input end of the control module is connected to the sampling module, and the output end of the control module is connected to the power conversion module.

[0023] like Figure 2 As shown, the external power grid of this embodiment inputs 220V AC voltage, which is input into the AC rectifier filter circuit, stepped down by transformer L300, and then rectified into smoother DC power by rectifier bridge D300. At this time, if the DC power is directly connected to the power conversion module, the voltage waveform and the current waveform will be inconsistent, resulting in low utilization. Therefore, in this embodiment, the DC power is first connected to the PFC adjustment module, which is composed of chip L4981AD, inductor capacitor and electronic components to adjust the current waveform and compensate for the phase difference between the current and voltage. It has the characteristics of small size, high efficiency and small ripple. The rectified voltage is fully boosted to a DC power higher than the peak voltage of the AC power by boosting, and then the electrolytic capacitors C24, C25 and C26 are placed in the boosted circuit for filtering, thereby improving the power factor.

[0024] like Figure 3 As shown, the power conversion module of this embodiment is composed of transistors Q1, Q2, Q3, Q4, and transformers T1 and T2, which convert the boosted DC power into high-frequency AC power, generate a constant excitation current after filtering by filter modules C4, C5, and C6, and then connect the frame of the component under test to the output end of the filter module.

[0025] like Figure 3As shown, the sampling circuit of this embodiment is connected to the frame of the component under test, and the voltage and current of the output end of the filter module are collected. The sampling resistors R99-R104 collect the output voltage signal (M_Vfeed+, M_Vfeed-), and the sampling resistors R3, R3A, R9-R12 collect the output current signal (M_Ifeed+, M_Ifeed-), and output it to the MCU module. The model of the MCU module of this embodiment is STM32F207. The MCU module uses Ohm's law R=U / I to calculate the on-resistance value of the product under test. When the on-resistance of the frame of the component under test is within the calibration range, the product is judged to be qualified, otherwise the product is judged to be unqualified. At the same time, the sampling circuit can control the power conversion module through the control module to change its pulse width or pulse frequency, so that the output end outputs the stable value required for the test.

[0026] like Figure 1 , 4 As shown in , 5, the control module of this embodiment includes a loop control module and a PWM control module, the input end of the loop control module is connected to the sampling module, the output end of the loop control module is connected to the input end of the PWM control module, and the output end of the PWM control module is connected to the power conversion module.

[0027] like Figure 1 As shown, the display module of this embodiment is connected to the MCU module and can display the actual on-resistance value.

[0028] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A photovoltaic panel grounding detection device based on a switching power supply, characterized in that: It includes AC rectification and filtering circuit, PFC adjustment module, power conversion module, sampling module, MCU module and control module; The input end of the AC rectifier and filter circuit is connected to the external power grid to input a 220V AC voltage, the output end of the AC rectifier and filter circuit is connected to the input end of the PFC adjustment module, the output end of the PFC adjustment module is connected to the input end of the power conversion module, and the output end of the power conversion module is connected to the frame of the component under test; The input end of the sampling module is connected to the frame of the component under test, and the output end of the sampling module is connected to the MCU module; The input end of the control module is connected to the sampling module, and the output end of the control module is connected to the power conversion module.

2. The photovoltaic panel grounding detection device based on a switching power supply according to claim 1, characterized in that: The control module includes a loop control module and a PWM control module. The input end of the loop control module is connected to the sampling module, the output end of the loop control module is connected to the input end of the PWM control module, and the output end of the PWM control module is connected to the power conversion module.

3. The photovoltaic panel grounding detection device based on a switching power supply according to claim 1, characterized in that: A filter module is connected between the output end of the power conversion module and the frame of the component under test.

4. The photovoltaic panel grounding detection device based on a switching power supply according to claim 1, characterized in that: It also includes a display module, which is connected to the MCU module.

Images