Intelligent recovery flyback switching power supply with high-voltage power grid input protection function
By designing high-voltage grid input protection and intelligent recovery circuits in flyback converters, the problem of easy damage to the switching devices of the flyback converter when inputting high-voltage grid is solved, intelligent protection and automatic recovery are achieved, and the reliability of the equipment is improved. stability.
Patent Information
- Application Number
- CN202421042213.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2034-05-14
AI Technical Summary
When flyback converters are input to high-voltage power grids, the switching devices are easily damaged, resulting in the power supply being unable to output normally and the equipment is prone to failure, especially in industrial environments.
An intelligent recovery type flyback switching power supply with high-voltage grid input protection function is designed, including high-voltage grid input protection and intelligent recovery circuit, flyback switch circuit, secondary rectification filter circuit and secondary voltage stabilization modulation circuit, and use stable Components such as voltage tubes, transistors, main control chips and diodes realize intelligent protection and automatic recovery of the high-voltage power grid.
It improves the reliability of flyback power supplies, provides self-protection and intelligent recovery capabilities, ensures that the equipment operates normally in harsh environments, and improves the reliability of switching power supplies.
Smart Images
Figure CN222321373U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of switching power supplies, and in particular relates to an intelligent recovery flyback switching power supply with a high-voltage power grid input protection function. Background Art
[0002] With the widespread application of electronic products, the market demand is growing, and the use of switching power supplies for electronic products and equipment is becoming more and more widespread. The flyback converter is the most commonly used topology. Its outstanding advantages are simplicity, reliability, low cost, and easy implementation.
[0003] In a flyback converter, if the voltage of the input grid suddenly increases, the switching device will be subjected to great voltage and current stress, which can easily cause damage to the switching device, resulting in the power supply failing to output normally and equipment failure. This situation is very easy to encounter in an industrial equipment environment. Utility Model Content
[0004] The utility model aims at solving the problems existing in the prior art and proposes the following technical solutions:
[0005] An intelligent recovery flyback switching power supply with high-voltage grid input protection function, including a high-voltage grid input protection and intelligent recovery circuit, a flyback switching circuit, a secondary rectification and filtering circuit, and a secondary voltage stabilization and modulation circuit;
[0006] In the high-grid input protection and intelligent recovery circuit, the cathode of the voltage regulator D11A is connected to the +V terminal, the anode of the voltage regulator D11A is connected to the cathode of the voltage regulator D11B, the anode of the voltage regulator D11B is connected to one end of the resistor R16, the other end of the resistor R16 is connected to one end of the resistor R12, the other end of the resistor R12 is connected to one end of the resistor R11 and the gate of the transistor Q1, and the other end of the resistor R11 is grounded; the capacitor C22 is connected at both ends of the resistor R11, and the voltage regulator D6A is also connected at both ends of the resistor R11; the source of the transistor Q1 is also grounded, the drain of the transistor Q1 is connected to the cathode of the diode D6, the anode of the diode D6 is connected to the feedback end of the 2nd pin of the IC1 main control chip, and is also connected to the 4th pin of the optical coupler PC1.
[0007] As a preferred embodiment of the above technical solution, in the flyback switch circuit, the AC L end is connected to one end of the fuse F1, the other end of the fuse F1 is connected to one end of the capacitor CX1, the other end of the capacitor CX1 is connected to the AC N end, one end of the capacitor CY4 is connected to one end of the capacitor CX1, the other end of the capacitor CY4 is connected to the earth PE, the other end of the capacitor CY3 is connected to the earth PE, the other end of the capacitor CY3 is connected to the AC N end, one end of the capacitor CY5 is connected to the negative electrode of the bridge stack BD1, the other end of the capacitor CY5 is connected to the earth PE, the two ends of the capacitor CX1 are connected to the two ends of the inductor L1, the other two ends of the inductor L1 are respectively connected to the AC end of the bridge stack BD1, and the positive electrode of the bridge stack BD1 is connected The positive electrode of capacitor C3, capacitor C3C and capacitor C3 are connected in series, the negative electrode of capacitor C3C is connected to the negative electrode of bridge stack BD1, capacitor C3A and capacitor C3B are connected in series and then connected in parallel at the positive and negative ends of bridge stack BD1, the positive electrode of bridge stack BD1 is connected to one end of the first winding of transformer T2, the other end of the first winding of transformer T2 is connected to the drain of field effect transistor Q2, resistor R43 and capacitor C4 are connected in parallel and then connected in series with diode D5 and then connected in parallel at the two ends of the first winding of transformer T2, the source of field effect transistor Q2 is connected to resistor R4 to the negative electrode of bridge stack BD1, the gate of field effect transistor Q2 is connected to the positive electrode of diode D9, resistor R23 is connected in parallel at both ends of diode D9, and the two The cathode of the transistor D9 is connected to the 5th pin of the main control chip IC1, one end of the resistor R14 is connected to the source of the field effect transistor Q2, the other end of the resistor R14 is connected to the 3rd pin of the main control chip IC1, the 1st pin of the main control chip IC1 is connected to the resistor R19 to one end of the second winding of the transformer T2, one end of the resistor R17 is connected to the 1st pin of the main control chip IC1, the other end of the resistor R17 is connected to the cathode of the bridge BD1, one end of the capacitor C14 is connected to the 2nd pin of the main control chip IC1, the other end of the capacitor C14 is connected to the cathode of the bridge BD1, the 2nd pin of the main control chip IC1 is connected to the 4th pin of the optocoupler PC1, the 3rd pin of the optocoupler PC1 is connected to the cathode of the bridge BD1, one end of the capacitor C15 is connected to the 3 pin, the other end of capacitor C15 is connected to the negative electrode of bridge stack BD1, 6 pin of main control chip IC1 is connected to the positive electrode of capacitor C19, the negative electrode of capacitor C19 is connected to the negative electrode of bridge stack BD1, one end of resistor R19A is connected to 6 pin of main control chip IC1, the other end of resistor R19A is connected to one end of the second winding of transformer T2, the other end of the second winding of transformer T2 is connected to the negative electrode of diode D8, the positive electrode of diode D8 is connected to the negative electrode of bridge stack BD1, one end of resistor R21 is connected to the positive electrode of bridge stack BD1, and the other end is connected to 8 pin of main control chip IC1, the negative electrode of diode D24 is connected to 8 pin of main control chip IC1, and the positive electrode of diode D24 is connected to the negative electrode of bridge stack BD1.
[0008] As a preferred embodiment of the above technical solution, in the secondary rectifier and filter circuit, one end of the third winding of the transformer T2 is connected to the positive electrode of the diode D22, the other end of the third winding of the transformer T2 is connected to the output voltage negative electrode VO-, the capacitor C25 and the resistor R30 are connected in series and connected to the two ends of the diode D22, one end of the resistor R9 is connected to the negative electrode of the diode D22, the other end of the resistor R9 is connected to the output voltage negative electrode VO-, the capacitor C7, the capacitor C3 and the capacitor C9 are connected in parallel to the two ends of the resistor R9, the inductor L6 is connected to the positive electrode of the capacitor C9, the other end of the inductor L6 is connected to the output voltage positive electrode VO+, one end of the capacitor C12B is connected to the output voltage negative electrode VO-, and the other end of the capacitor C12B is connected to the ground.
[0009] As a preferred embodiment of the above technical solution, in the secondary voltage regulation modulation circuit, one end of the optocoupler PC1 is connected to one end of the resistor R40, the other end of the resistor R40 is connected to the output voltage positive electrode VO+, the resistor R31 is connected in parallel between the 1st and 2nd pins of the optocoupler PC1, the 2nd pin of the optocoupler PC1 is connected to the cathode K pin of the TL431 voltage regulator IC3, the anode A pin of the TL431 voltage regulator IC3 is connected to the output voltage negative electrode VO-, the reference end R pin of the TL431 voltage regulator IC3 is connected to one end of the resistor R72, the other end of the resistor R72 is connected to one end of the potentiometer VRA, and the other end of the potentiometer VRA is connected to the output voltage negative electrode VO-, one end of the resistor R36 is connected to the output voltage positive electrode VO+, the other end of the resistor R36 is connected to the reference end R pin of the TL431 voltage regulator IC3, and the capacitor C27 and the resistor R32 are connected in series and connected between the cathode K pin and the reference end R pin of the TL431 voltage regulator IC3.
[0010] The beneficial effects of the utility model are:
[0011] The utility model utilizes high voltage grid input intelligent protection and intelligent recovery circuits to improve the reliability of the flyback power supply, so that the switching power supply has the ability of self-protection and intelligent recovery, ensures the reliable operation of the equipment, and also improves the reliability of the switching power supply when used in harsh environments. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 A schematic diagram of the topology of an intelligent recovery flyback switching power supply with a high-voltage grid input protection function;
[0013] Figure 2 Schematic diagram of the topological structure of the flyback converter;
[0014] Figure 3 It is a schematic diagram of the topological structure of the high power grid input protection and intelligent recovery circuit;
[0015] Figure 4 Schematic diagram of the topological structure of the flyback switch circuit;
[0016] Figure 5 It is a schematic diagram of the topological structure of the secondary rectifier and filter circuit;
[0017] Figure 6 This is a schematic diagram of the topology of the secondary voltage regulation modulation circuit. DETAILED DESCRIPTION
[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present utility model clearer, the technical solution of the present utility model will be clearly and completely described below in conjunction with the embodiments.
[0019] Figure 1 The topological structure diagram of the intelligent recovery flyback switching power supply with high voltage grid input protection function is shown. The switching power supply includes a high grid input protection and intelligent recovery circuit, a flyback switching circuit, a secondary rectifier filter circuit and a secondary voltage stabilization modulation circuit.
[0020] The technical solution adopted by the utility model is: high voltage grid input intelligent protection and intelligent recovery circuit to improve the reliability of the flyback power supply.
[0021] Figure 2 The figure shows the schematic diagram of the topological structure of the flyback converter. First of all, the flyback converter circuit has the characteristics of simple topology. The transformer is used for electrical isolation. The principle is simple and it is widely used in the switching circuit of the power supply. In the flyback converter, the transformer plays the dual role of inductor and transformer. Its circuit structure is simple and the working principle is not complicated.
[0022] Among them, the working principle of the flyback converter is: when the main switch tube Q is turned on, the secondary side diode D is turned off, and the transformer T stores energy; when the main switch tube Q is turned off, the secondary side diode D is turned on, and the transformer T releases the stored energy to the load. It is different from the forward converter. The transformer excitation inductance energy storage of the forward converter is generally very small, and the algebraic sum of the instantaneous power of each winding is zero. The transformer only plays the role of isolation and voltage transformation. The transformer of the flyback converter is relatively special. It also plays the role of energy storage inductor and is called an energy storage transformer (or inductor-transformer). In order to prevent the core from saturating when the load current is large, the transformer core of the flyback converter must be added with an air gap to reduce the magnetic permeability of the core, avoid the sudden change of current caused by the core saturation, and damage the main switch device.
[0023] When the grid input suddenly increases, the voltage of VIN also increases accordingly, and the duty cycle of the switching circuit decreases as the input voltage increases or the load decreases. This will cause the duty cycle to decrease when the high-voltage grid is input and at the minimum load, so it is necessary to ensure that the controller can operate normally during this minimum on-time. The reverse voltage that the main switching device can withstand continues to rise, the switching loss and transformer loss increase, the reliability of the power supply weakens, and the switch tube is easily damaged. Protection measures must be taken to prevent power damage. When the grid returns to normal, the protection can be released to allow the power supply to output normally.
[0024] For high voltage grid input intelligent protection and intelligent recovery circuit:
[0025] Figure 3 This is a schematic diagram of the topology of the high-voltage power grid input protection and intelligent recovery circuit. Based on the main control chip IC12 pin FB (feedback protection function), when the voltage of the power grid suddenly increases, the voltage at the +V end also increases. When the preset protection point voltage is reached, the voltage-stabilizing diodes D11A and D11B are turned on, and voltage is generated on resistors R16 and R12, which turns on transistor Q1, pulls the voltage at the feedback end of the main control chip IC12 pin FB down to the ground, and controls the main control chip IC1 to turn off the drive function of pin 5, stops the switch tube from working, and the power supply has no output, which plays a protective role. When the voltage of the power grid returns to normal, the voltage-stabilizing diode will not conduct, and the transistor Q1 will not conduct either. The voltage at the main control chip IC12 pin FB returns to normal, and the power supply starts to output normally.
[0026] in addition, Figure 4The figure shows a schematic diagram of the topological structure of the flyback switch circuit. In the flyback switch circuit, the AC L terminal is connected to one end of the fuse F1, the other end of the fuse F1 is connected to one end of the capacitor CX1, the other end of the capacitor CX1 is connected to the AC N terminal, one end of the capacitor CY4 is connected to one end of the capacitor CX1, the other end of the capacitor CY4 is connected to the earth PE, the other end of the capacitor CY3 is connected to the earth PE, the other end of the capacitor CY3 is connected to the AC N terminal, one end of the capacitor CY5 is connected to the negative electrode of the bridge BD1, the other end of the capacitor CY5 is connected to the earth PE, the two ends of the capacitor CX1 are connected to the two ends of the inductor L1, the other two ends of the inductor L1 are respectively connected to the AC end of the bridge BD1, the positive electrode of the bridge BD1 is connected to the positive electrode of the capacitor C3, and the capacitor C 3C is connected in series with capacitor C3, the negative electrode of capacitor C3C is connected to the negative electrode of bridge stack BD1, capacitor C3A and capacitor C3B are connected in series and then connected in parallel at the positive and negative ends of bridge stack BD1, the positive electrode of bridge stack BD1 is connected to one end of the first winding of transformer T2, the other end of the first winding of transformer T2 is connected to the drain of field effect transistor Q2, resistor R43 and capacitor C4 are connected in parallel and then connected in series with diode D5 and then connected in parallel at the two ends of the first winding of transformer T2, the source of field effect transistor Q2 is connected to resistor R4 to the negative electrode of bridge stack BD1, the gate of field effect transistor Q2 is connected to the positive electrode of diode D9, resistor R23 is connected in parallel at both ends of diode D9, and the negative electrode of diode D9 Connected to pin 5 of the main control chip IC1, one end of the resistor R14 is connected to the source of the field effect tube Q2, and the other end of the resistor R14 is connected to pin 3 of the main control chip IC1. Pin 1 of the main control chip IC1 is connected to resistor R19 to one end of the second winding of the transformer T2. One end of the resistor R17 is connected to pin 1 of the main control chip IC1, and the other end of the resistor R17 is connected to the negative electrode of the bridge stack BD1. One end of the capacitor C14 is connected to pin 2 of the main control chip IC1, and the other end of the capacitor C14 is connected to the negative electrode of the bridge stack BD1. Pin 2 of the main control chip IC1 is connected to pin 4 of the optocoupler PC1, and pin 3 of the optocoupler PC1 is connected to the negative electrode of the bridge stack BD1. One end of the capacitor C15 is connected to pin 3 of the main control chip IC1. The other end of capacitor C15 is connected to the negative electrode of bridge stack BD1, pin 6 of main control chip IC1 is connected to the positive electrode of capacitor C19, the negative electrode of capacitor C19 is connected to the negative electrode of bridge stack BD1, one end of resistor R19A is connected to pin 6 of main control chip IC1, the other end of resistor R19A is connected to one end of the second winding of transformer T2, the other end of the second winding of transformer T2 is connected to the negative electrode of diode D8, the positive electrode of diode D8 is connected to the negative electrode of bridge stack BD1, one end of resistor R21 is connected to the positive electrode of bridge stack BD1, and the other end is connected to pin 8 of main control chip IC1, the negative electrode of diode D24 is connected to pin 8 of main control chip IC1, and the positive electrode of diode D24 is connected to the negative electrode of bridge stack BD1.
[0027] Figure 5What is shown is a schematic diagram of the topological structure of a secondary rectifier and filter circuit. In the secondary rectifier and filter circuit, one end of the third winding of the transformer T2 is connected to the positive electrode of the diode D22, the other end of the third winding of the transformer T2 is connected to the output voltage negative electrode VO-, the capacitor C25 and the resistor R30 are connected in series and connected to the two ends of the diode D22, one end of the resistor R9 is connected to the negative electrode of the diode D22, the other end of the resistor R9 is connected to the output voltage negative electrode VO-, the capacitor C7, the capacitor C3 and the capacitor C9 are connected in parallel to the two ends of the resistor R9, the inductor L6 is connected to the positive electrode of the capacitor C9, the other end of the inductor L6 is connected to the output voltage positive electrode VO+, one end of the capacitor C12B is connected to the output voltage negative electrode VO-, and the other end of the capacitor C12B is connected to the ground.
[0028] Figure 6 The diagram shows the topological structure of the secondary voltage regulation modulation circuit. In the secondary voltage regulation modulation circuit, one end of the optocoupler PC1 is connected to one end of the resistor R40, the other end of the resistor R40 is connected to the output voltage positive electrode VO+, the resistor R31 is connected in parallel between the 1st and 2nd pins of the optocoupler PC1, the 2nd pin of the optocoupler PC1 is connected to the cathode K pin of the TL431 voltage regulator IC3, the anode A pin of the TL431 voltage regulator IC3 is connected to the output voltage negative electrode VO-, the reference end R pin of the TL431 voltage regulator IC3 is connected to one end of the resistor R72, the other end of the resistor R72 is connected to one end of the potentiometer VRA, the other end of the potentiometer VRA is connected to the output voltage negative electrode VO-, one end of the resistor R36 is connected to the output voltage positive electrode VO+, the other end of the resistor R36 is connected to the reference end R pin of the TL431 voltage regulator IC3, the capacitor C27 and the resistor R32 are connected in series and connected between the cathode K pin and the reference end R pin of the TL431 voltage regulator IC3.
[0029] The above embodiments are only used to illustrate the technical solution of the present invention, but not to limit it.
Claims
1. Intelligent recovery flyback switching power supply with high voltage grid input protection function, characterized in that: It includes high grid input protection and intelligent recovery circuit, flyback switch circuit, secondary rectification and filtering circuit and secondary voltage regulation and modulation circuit; In the high-grid input protection and intelligent recovery circuit, the cathode of the voltage regulator D11A is connected to the +V terminal, the anode of the voltage regulator D11A is connected to the cathode of the voltage regulator D11B, the anode of the voltage regulator D11B is connected to one end of the resistor R16, the other end of the resistor R16 is connected to one end of the resistor R12, the other end of the resistor R12 is connected to one end of the resistor R11 and the gate of the transistor Q1, and the other end of the resistor R11 is grounded; the capacitor C22 is connected at both ends of the resistor R11, and the voltage regulator D6A is also connected at both ends of the resistor R11; the source of the transistor Q1 is also grounded, the drain of the transistor Q1 is connected to the cathode of the diode D6, the anode of the diode D6 is connected to the feedback end of the 2nd pin of the IC1 main control chip, and is also connected to the 4th pin of the optical coupler PC1.
2. The intelligent recovery flyback switching power supply with high voltage grid input protection function according to claim 1 is characterized in that: In the flyback switch circuit, the AC L end is connected to one end of the fuse F1, the other end of the fuse F1 is connected to one end of the capacitor CX1, the other end of the capacitor CX1 is connected to the AC N end, one end of the capacitor CY4 is connected to one end of the capacitor CX1, the other end of the capacitor CY4 is connected to the earth PE, the other end of the capacitor CY3 is connected to the earth PE, the other end of the capacitor CY3 is connected to the AC N end, one end of the capacitor CY5 is connected to the negative electrode of the bridge stack BD1, the other end of the capacitor CY5 is connected to the earth PE, the two ends of the capacitor CX1 are connected to the two ends of the inductor L1, the other two ends of the inductor L1 are respectively connected to the AC end of the bridge stack BD1, the positive electrode of the bridge stack BD1 is connected to the positive electrode of the capacitor C3, and the inductor L1 is connected to the AC end of the bridge stack BD1. Capacitor C3C is connected in series with capacitor C3, the negative electrode of capacitor C3C is connected to the negative electrode of bridge stack BD1, capacitor C3A and capacitor C3B are connected in series and then connected in parallel to the positive and negative ends of bridge stack BD1, the positive electrode of bridge stack BD1 is connected to one end of the first winding of transformer T2, the other end of the first winding of transformer T2 is connected to the drain of field effect transistor Q2, resistor R43 and capacitor C4 are connected in parallel with diode D5 and then connected in parallel to the two ends of the first winding of transformer T2, the source of field effect transistor Q2 is connected to resistor R4 to the negative electrode of bridge stack BD1, the gate of field effect transistor Q2 is connected to the positive electrode of diode D9, resistor R23 is connected in parallel to the two ends of diode D9, the negative electrode of diode D9 The electrode is connected to the 5th pin of the main control chip IC1, one end of the resistor R14 is connected to the source of the field effect tube Q2, and the other end of the resistor R14 is connected to the 3rd pin of the main control chip IC1. The 1st pin of the main control chip IC1 is connected to the resistor R19 to one end of the second winding of the transformer T2. One end of the resistor R17 is connected to the 1st pin of the main control chip IC1, and the other end of the resistor R17 is connected to the negative electrode of the bridge stack BD1. One end of the capacitor C14 is connected to the 2nd pin of the main control chip IC1, and the other end of the capacitor C14 is connected to the negative electrode of the bridge stack BD1. The 2nd pin of the main control chip IC1 is connected to the 4th pin of the optocoupler PC1, and the 3rd pin of the optocoupler PC1 is connected to the negative electrode of the bridge stack BD1. One end of the capacitor C15 is connected to the 3rd pin of the main control chip IC1. The other end of capacitor C15 is connected to the negative electrode of bridge stack BD1, pin 6 of main control chip IC1 is connected to the positive electrode of capacitor C19, the negative electrode of capacitor C19 is connected to the negative electrode of bridge stack BD1, one end of resistor R19A is connected to pin 6 of main control chip IC1, the other end of resistor R19A is connected to one end of the second winding of transformer T2, the other end of the second winding of transformer T2 is connected to the negative electrode of diode D8, the positive electrode of diode D8 is connected to the negative electrode of bridge stack BD1, one end of resistor R21 is connected to the positive electrode of bridge stack BD1, and the other end is connected to pin 8 of main control chip IC1, the negative electrode of diode D24 is connected to pin 8 of main control chip IC1, and the positive electrode of diode D24 is connected to the negative electrode of bridge stack BD1.
3. The intelligent recovery flyback switching power supply with high voltage grid input protection function according to claim 2 is characterized in that: In the secondary rectifier and filter circuit, one end of the third winding of the transformer T2 is connected to the positive electrode of the diode D22, the other end of the third winding of the transformer T2 is connected to the output voltage negative electrode VO-, the capacitor C25 and the resistor R30 are connected in series and connected to the two ends of the diode D22, one end of the resistor R9 is connected to the negative electrode of the diode D22, the other end of the resistor R9 is connected to the output voltage negative electrode VO-, the capacitor C7, the capacitor C3 and the capacitor C9 are connected in parallel to the two ends of the resistor R9, the inductor L6 is connected to the positive electrode of the capacitor C9, the other end of the inductor L6 is connected to the output voltage positive electrode VO+, one end of the capacitor C12B is connected to the output voltage negative electrode VO-, and the other end of the capacitor C12B is connected to the ground.
4. The intelligent recovery flyback switching power supply with high voltage grid input protection function according to claim 3 is characterized in that: In the secondary voltage regulation modulation circuit, one end of the optocoupler PC1 is connected to one end of the resistor R40, the other end of the resistor R40 is connected to the output voltage positive electrode VO+, the resistor R31 is connected in parallel between the 1st and 2nd pins of the optocoupler PC1, the 2nd pin of the optocoupler PC1 is connected to the cathode K pin of the TL431 voltage regulator IC3, the anode A pin of the TL431 voltage regulator IC3 is connected to the output voltage negative electrode VO-, the reference end R pin of the TL431 voltage regulator IC3 is connected to one end of the resistor R72, the other end of the resistor R72 is connected to one end of the potentiometer VRA, the other end of the potentiometer VRA is connected to the output voltage negative electrode VO-, one end of the resistor R36 is connected to the output voltage positive electrode VO+, the other end of the resistor R36 is connected to the reference end R pin of the TL431 voltage regulator IC3, the capacitor C27 and the resistor R32 are connected in series and connected between the cathode K pin and the reference end R pin of the TL431 voltage regulator IC3.