Photovoltaic optimization system DC-DC MOS short circuit anti-burning circuit structure and control method
By designing a DC-DC MOS short-circuit protection circuit structure for a photovoltaic optimizer system and using an MCU to control the switching transistors to turn on and off, the safety hazards of traditional photovoltaic optimizers during short circuits are solved, thereby improving the safety of photovoltaic modules and the reliability of the system.
Patent Information
- Application Number
- CN202410980671.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2026-01-23
AI Technical Summary
Traditional photovoltaic optimizers have safety hazards due to their non-isolated circuit structure, especially in the event of a short circuit, which can easily cause combustion, damage the photovoltaic modules, and potentially shut down the entire system.
A DC-DC MOS short-circuit protection circuit structure for a photovoltaic optimizer system was designed. The microcontroller unit (MCU) samples the voltage and controls the switching transistor to turn on and off according to the algorithm to avoid current flowing under short-circuit conditions. A parallel structure of power MOS transistor and freewheeling diode is adopted.
It effectively prevents photovoltaic optimizers from burning out under short-circuit conditions, ensures the safety of photovoltaic modules, improves system reliability, and avoids the risk of downtime.
Smart Images
Figure FT_1
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to a photovoltaic optimizer system DC-DC MOS short-circuit anti-burning circuit structure and a control method, and belongs to the technical field of photovoltaic power generation. BACKGROUND
[0002] With the rapid development of the global economy and the continuous growth of the population, energy demand is rising. However, traditional fossil energy resources such as coal, oil, and natural gas are limited, and the greenhouse gas emissions and pollution generated during their mining, transportation, and use have had a great impact on the environment and human health. In order to achieve the goal of sustainable development, we urgently need to reduce the dependence of society on fossil energy and actively develop new energy.
[0003] With the development of photovoltaic power generation technology, based on distributed photovoltaic power generation system and maximum power point tracking control (MPPT), each photovoltaic component can work at the maximum power point, and has the advantages of high power generation efficiency and high system reliability. However, the traditional photovoltaic optimizer usually adopts a non-isolated circuit structure, and once a safety hazard occurs, it will expand the scope of damage. In particular, a short circuit in the circuit will cause the optimizer to burn, damage the photovoltaic component, and even stop the entire photovoltaic system from working. In order to solve this problem, the application proposes a new circuit structure that can effectively solve the short-circuit anti-burning problem of power optimizer products, and is particularly suitable for application in household and commercial distributed photovoltaic power generation systems. SUMMARY
[0004] The application provides a photovoltaic optimizer system DC-DC MOS short-circuit anti-burning circuit structure and a control method to solve the safety problems, high cost, and low efficiency of traditional photovoltaic optimizers that use non-isolated converters.
[0005] The power circuit comprises an input capacitor C21, a switch tube Q21, a switch tube Q22, a switch tube Q23, an inductor L1, an output capacitor C22, and a freewheeling diode D23. The input capacitor C21, an input resistor R1, and the switch tube Q23 are connected to the positive electrode of a photovoltaic component, the positive electrode of the photovoltaic component is connected to a first output terminal, the output capacitor C22 is connected in parallel to an output terminal, the inductor L1 is connected to the negative output terminal, and the other end is connected to Q22 and Q23. The negative electrode of the photovoltaic component is connected to the switch tube Q21, and the other end is connected to Q22. The switch tube Q23 is connected in parallel to the freewheeling diode D23. The switch tubes Q21 and Q22 are power MOS tubes. BRIEF DESCRIPTION OF DRAWINGS
[0006] The application has the following drawings: Figure 1The circuit structure diagram of the application.
[0007] Figure 1 The micro control unit (MCU), the first switch tube Q21, the second switch tube Q22, the third switch tube Q23, the first capacitor C21, the second capacitor C22, the third capacitor C3, the first resistor R1, the second resistor R3, the third resistor R5, the fourth resistor R6, the fifth resistor R7, the first inductor L1, the first diode D2 and the second diode D23 are constituted The micro control unit MCU, the third resistor R5, the fourth resistor R6 and the fifth resistor R7 constitute a control circuit, and a power circuit comprises the input capacitor C21, the switch tube Q21, the switch tube Q22, the switch tube Q23, the inductor L1 and the output capacitor C22, and the freewheeling diode D23. The input capacitor C21, the input resistor R1, the switch tube Q23 are connected with the positive pole of the photovoltaic module, the positive pole of the photovoltaic module is connected with the first output terminal, the output capacitor C22 is connected with the output terminal in parallel, the inductor L1 is connected with the output negative terminal, and the other end is connected with Q22 and Q23; the negative pole of the photovoltaic module is connected with the switch tube Q21, and the other end is connected with Q22; the switch tube Q23 is connected with the freewheeling diode D23 in parallel; and the switch tubes Q21, Q22 and Q23 are power MOS tubes.
[0008] The application has the beneficial effects that the problem of burning caused by short circuit of a solar power optimizer is effectively solved. Specific implementation
[0009] The technical solutions of the application will be further described below. Figure 1 The technical solutions of the application will be further described below.
[0010] The photovoltaic optimizer samples the voltage of Uadc-GND2 through the MCU before starting to work, and the voltage Ugnd2 is obtained through a program algorithm. When the voltage Ugnd2 is within the range of Ugnd2(min)~Ugnd2(max), the program algorithm judges that the MOS tube of the optimizer is in a normal state, the MCU opens Q21 and Q22, and the optimizer starts to work. When Ugnd2<Ugnd2(min), the program algorithm judges that Q21 is short-circuited and damaged, at this time, the program will not open Q22 and Q23, Q22 and Q23 will be in a normally closed state, at this time, the photovoltaic module corresponding to the optimizer is in a bypass state, and Q21 will not have current flowing therethrough, so the burning condition will not occur. When Ugnd2>Ugnd2(max), the program algorithm judges that Q22 and Q23 are simultaneously short-circuited and damaged, at this time, the program will not open Q21, and Q21 will be in a normally closed state, at this time, the photovoltaic module corresponding to the optimizer is in a bypass state, and current flows through D23, Q22 and Q23, so the burning condition will not occur.
[0011] The following three formulas are the calculation methods of Ugnd2(max), Ugnd2(min) and Ugnd2 adc-GND2
[0012]
[0013]
[0014]
[0015] The basic principles and main features of the present application and the advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.
Claims
1. A photovoltaic optimization system DC-DC mos short circuit burn prevention control method, characterized in that The photovoltaic DC-DC MOS short-circuit burnout mechanism control circuit is composed of a micro control unit (MCU), a first switch tube Q21, a second switch tube Q22, a third switch tube Q23, a first capacitor C21, a second capacitor C22, a third capacitor C3, a first resistor R1, a second resistor R3, a third resistor R5, a fourth resistor R6, a fifth resistor R7, a first inductor L1, a first diode D2 and a second diode D23.
2. Wherein the micro control unit MCU and the third resistor R5, the fourth resistor R6 and the fifth resistor R7 constitute a control circuit, and a power circuit comprises an input capacitor C21, switch tubes Q21, Q22 and Q23, an inductor L1, an output capacitor C22 and a freewheeling diode D23. The input capacitor C21, an input resistor R1, the switch tube Q23 are connected to the positive pole of a photovoltaic module, the positive pole of the photovoltaic module is connected to a first output terminal, the output capacitor C22 is connected in parallel to an output terminal, the inductor L1 is connected to the negative pole of the output terminal, and the other end is connected to Q22 and Q23; the negative pole of the photovoltaic module is connected to the switch tube Q21, and the other end is connected to Q22; the switch tube Q23 is connected in parallel to the freewheeling diode D23; and the switch tubes Q21, Q22 and Q23 are power MOS tubes.