High-frequency switching power supply

Abstract

The utility model relates to the technical field of switching power supplies, in particular to a high-frequency switching power supply, which comprises a main circuit and a main control circuit which are electrically connected, the main circuit comprises an input filter, a power filter, an inverter circuit and an output power filter, and the main control circuit comprises an auxiliary power supply, a control circuit and a detection circuit. The input and output power lines are provided with ferrite magnetic rings and are close to the ground wire. According to the utility model, the power supply filter is additionally arranged at the inlet of the switching power supply, higher harmonics generated by the switching power supply are suppressed, the ferrite magnetic rings are additionally arranged on the input and output power lines, and the power lines are close to the ground wire, so that on one hand, high-frequency common modes in the power lines are suppressed; and on the other hand, disturbance energy radiated by a power line is reduced, the power line is as close as possible to a ground wire to reduce the loop area of differential mode radiation, an input alternating-current power line and an output direct-current power line are wired separately, electromagnetic coupling between input and output is reduced, and disturbance of radiation is reduced.

Description

Technical Field

[0001] The utility model relates to a switching power supply, in particular to a high-frequency switching power supply, belonging to the technical field of switching power supplies. Background Art

[0002] The DC power supply consists of devices such as high-frequency switching power supply modules and storage batteries. The intelligent high-frequency switching power supply system has the characteristics of small volume, light weight, high efficiency, small ripple coefficient, fast dynamic response, high control precision, module superposition output, N+1 redundancy, etc. The quality of the maintenance of the DC system equipment is not only related to the reliability and service life of the intelligent high-frequency switching power supply system, but also directly affects whether the control and protection systems of the relevant systems can operate normally.

[0003] In the state where the circuit is in high-frequency conduction and cut-off, the opening and closing speeds of the switching tubes are getting faster and faster, generally within a few microseconds. When the switching tubes open and close at such a speed, surge voltages and surge currents are formed, generating high-frequency and high-voltage spike harmonics, which cause electromagnetic interference to the space and the AC input line. While the high-frequency transformer T1 performs power conversion, an alternating electromagnetic field is generated, radiating electromagnetic waves into the space, forming radiation interference.

[0004] Therefore, it is urgent to improve the high-frequency switching power supply to solve the above existing problems. Content of the Utility Model

[0005] The purpose of the utility model is to provide a high-frequency switching power supply. A power filter is added at the entrance of the switching power supply to suppress the high-order harmonics generated by the switching power supply. Ferrite magnetic rings are added to the input and output power lines, and the power lines are close to the ground wire. Ferrite magnetic rings are added to the input and output power lines. On the one hand, it suppresses the high-frequency common mode in the power lines, and on the other hand, it reduces the interference energy radiated through the power lines. The power lines are as close to the ground wire as possible to reduce the loop area of differential-mode radiation. The input AC power line and the output DC power line are routed separately to reduce the electromagnetic coupling between the input and output and reduce the radiated interference.

[0006] In order to achieve the above purpose, the main technical solutions adopted by the utility model include:

[0007] A high-frequency switching power supply includes a main circuit and a main control circuit that are electrically connected. The main circuit includes input filtering, power filtering, an inverter circuit, and output power filtering. The main control circuit includes an auxiliary power supply, a control circuit, and a detection circuit;

[0008] The auxiliary power supply, the inverter circuit, and the output power filtering are all communicatively connected to the control circuit;

[0009] The input filter is electrically connected to the power filter through a rectifier bridge. The power filter includes an inductor L1 and a power transistor Q1. The inverter circuit includes power transistors Q2, Q3, Q4, and Q5. The inverter circuit is electrically connected to the output power filter through a high-frequency transformer T1. A rectifier diode D1 and a rectifier diode D2 are arranged in parallel on the output power filter. A capacitor C3 is arranged in parallel with the rectifier diode D1, and a capacitor C4 is arranged in parallel with the rectifier diode D2. A ferrite bead is added to the input and output power lines, and the power line is close to the ground wire.

[0010] Preferably, a capacitor C1 is arranged in parallel with the power transistor Q1. The output end of the rectifier bridge is connected to a diode D3 through the inductor L1. The inductor L1 is arranged in parallel with the power transistor Q1. A capacitor C5 is electrically connected to the diode D3.

[0011] Preferably, the power transistor Q2 and the power transistor Q3 are arranged in parallel, the power transistor Q4 and the power transistor Q5 are arranged in parallel, and a capacitor C2 is arranged between the inverter circuit and the high-frequency transformer T1.

[0012] Preferably, a resistor R1 is arranged in series with the capacitor C3, a resistor R2 is arranged in series with the capacitor C4, and a resistor R3 is electrically connected through a high-frequency transformer T2 after the rectifier diodes D1 and D2 are connected in parallel.

[0013] Preferably, the control circuit includes a capacitor C7 and a diode D4 arranged in parallel. One side of the diode D4 is arranged in parallel with a capacitor C6 and a resistor RL through an inductor L3;

[0014] A switch K is electrically connected between the capacitor C7 and the diode D4.

[0015] Preferably, the detection circuit includes an ammeter, a voltmeter, an oscilloscope, and a logic analyzer.

[0016] Preferably, a protection circuit is electrically connected between the auxiliary power supply and the detection circuit. The protection circuit includes a switch, a fuse, a relay, a sensor, and a delay element.

[0017] The utility model has at least the following beneficial effects:

[0018] 1. Add a power filter at the inlet of the switching power supply to suppress the high-order harmonics generated by the switching power supply. Add ferrite magnetic beads to the input and output power lines. The power lines should be close to the ground wire. Adding ferrite magnetic beads to the input and output power lines can suppress the high-frequency common mode in the power lines on the one hand and reduce the interference energy radiated through the power lines on the other hand. The power lines should be as close to the ground wire as possible to reduce the loop area of differential-mode radiation. Separate the input AC power line and the output DC power line to reduce the electromagnetic coupling between the input and output and lower the radiated interference.

[0019] 2. The function of the input filter is to filter out the noise existing in the power grid and also prevent the noise generated by this machine from being fed back to the common power grid. The power filter directly rectifies the AC power from the power grid into relatively smooth DC power for the next-stage conversion. The inverter circuit converts the rectified DC power into high-frequency AC power, which is the core part of the high-frequency switching power supply. The higher the frequency, the smaller the ratio of volume, weight to output power. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0021] Figure 1 is the schematic diagram of the present utility model;

[0022] Figure 2 is the main circuit of the present utility model Figure 1 ;

[0023] Figure 3 is the main circuit of the present utility model Figure 2 ;

[0024] Figure 4 is the control circuit diagram of the present utility model.

[0025] In the figure, 1. Input filter; 2. Power filter; 3. Inverter circuit; 4. Output power filter; 5. Control circuit; 6. Auxiliary power supply; 7. Protection circuit; 8. Detection circuit; 100. Main circuit; 200. Main control circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following will detail the implementation manners of the present application in conjunction with the drawings and embodiments, so as to fully understand how the present application uses technical means to solve technical problems and achieve the realization process of technical effects and implement accordingly.

[0027] As Figures 1-4As shown in the figure, the high-frequency switching power supply provided in this embodiment includes a main circuit 100 and a main control circuit 200 that are electrically connected. The main circuit 100 includes an input filter 1, a power filter 2, an inverter circuit 3, and an output power filter 4. The main control circuit 200 includes an auxiliary power supply 6, a control circuit 5, and a detection circuit 8.

[0028] The DC power supply consists of devices such as high-frequency switching power supply modules and storage batteries. The intelligent high-frequency switching power supply system has the characteristics of small volume, light weight, high efficiency, small ripple coefficient, fast dynamic response, high control accuracy, module superposition output, N+1 redundancy, etc. The quality of the maintenance of DC system equipment is not only related to the reliability and lifespan of the intelligent high-frequency switching power supply system, but also directly affects whether the control and protection systems of related systems can operate normally. The auxiliary power supply 6, the inverter circuit 3, and the output power filter 4 are all communicatively connected to the control circuit 5. A capacitor C1 is connected in parallel to the power transistor Q1. The output terminal of the rectifier bridge is connected to a diode D3 through an inductor L1. The inductor L1 is connected in parallel to the power transistor Q1. A capacitor C5 is electrically connected to the diode D3. The input filter 1 is electrically connected to the power filter 2 through a rectifier bridge. The power filter 2 includes an inductor L1 and a power transistor Q1. The inverter circuit 3 includes power transistors Q2, Q3, Q4, and Q5. The inverter circuit 3 is electrically connected to the output power filter 4 through a high-frequency transformer T1. Rectifier diodes D1 and D2 are connected in parallel to the output power filter 4. A capacitor C3 is connected in parallel to the rectifier diode D1. A capacitor C4 is connected in parallel to the rectifier diode D2. The rectifier bridge, the power transistor Q1, the power transistors Q2-Q5, the high-frequency transformer T1, and the output rectifier diodes D1-D2 are the main sources of electromagnetic interference generated during the operation of the high-frequency switching power supply. The power transistor Q2 is connected in parallel to the power transistor Q3. The power transistors Q4 and Q5 are connected in parallel. A capacitor C2 is provided between the inverter circuit 3 and the high-frequency transformer T1. A resistor R1 is connected in series to the capacitor C3. A resistor R2 is connected in series to the capacitor C4. After the rectifier diodes D1 and D2 are connected in parallel, they are electrically connected to a resistor R3 through a high-frequency transformer T2. The switching power transistor operates in a state of high-frequency conduction and cutoff. In order to reduce switching losses, improve the power density and overall efficiency of the power supply, the opening and closing speeds of the switching transistors are getting faster and faster, generally within a few microseconds. When the switching transistors open and close at such speeds, surge voltages and surge currents are formed, generating high-frequency and high-voltage spike harmonics, which cause electromagnetic interference to the space and the AC input line. While the high-frequency transformer T1 performs power conversion, it generates an alternating electromagnetic field, radiating electromagnetic waves into the space, forming radiation interference. A power filter is added at the entrance of the switching power supply to suppress the high-order harmonics generated by the switching power supply.

[0029] At the same time, add ferrite beads to the input and output power lines. The power lines should be close to the ground wire. Adding ferrite beads to the input and output power lines can, on the one hand, suppress the high-frequency common mode in the power lines, and on the other hand, reduce the interference energy radiated through the power lines. The power lines should be as close to the ground wire as possible to reduce the loop area of differential-mode radiation. Separate the input AC power line and the output DC power line to reduce the electromagnetic coupling between the input and output. The signal lines should be far from the power lines and close to the ground wire to reduce the loop area of the circuit. The line width on the PCB board should not change suddenly, and the corners should be rounded;

[0030] The function of input filter 1 is to filter out the noise existing in the power grid, and at the same time, it also blocks the noise generated by this machine from being fed back to the common power grid. Power filter 2 directly rectifies the AC power from the power grid into relatively smooth DC power for the next-stage conversion. Inverter circuit 3 converts the rectified DC power into high-frequency AC power, which is the core part of the high-frequency switching power supply. The higher the frequency, the smaller the ratio of volume, weight to output power.

[0031] Furthermore, as Figure 4 shown, the control circuit 5 includes a capacitor C7 and a diode D4 connected in parallel. One side of the diode D4 is connected in parallel with a capacitor C6 and a resistor RL through an inductor L3;

[0032] There is a switch K electrically connected between the capacitor C7 and the diode D4. The switch K is repeatedly turned on and off at a certain time interval. When the switch K is turned on, the input power supply E is supplied to the load RL through the switch K and the filter circuit. During the entire period when the switch is on, the power supply E provides energy to the load. When the switch K is turned off, the input power supply E interrupts the energy supply. A part of the energy is stored when the switch is on and released to the load when the switch is off. The circuit composed of the inductor L3, the capacitor C7, and the diode D4 has this function. The inductor L3 is used to store energy. When the switch K is turned off, the energy stored in the inductor L3 is released to the load through the diode D4, so that the load can obtain continuous and stable energy. Because the diode D4 makes the load current continuous, it is called a freewheeling diode. The average value of the formed voltage E can be expressed by the following formula:

[0033] E = TON / T * E;

[0034] Among them, TON is the time for each turn-on of the switch, and T is the working cycle of the switch on and off, that is, the sum of the switch-on time TON and the switch-off time TOFF.

[0035] Even further, as Figure 1As shown, the detection circuit 8 includes an ammeter, a voltmeter, an oscilloscope, and a logic analyzer. In addition to providing various parameters during the operation of the protection circuit, it also provides data of various display instruments. There is an electrical connection between the auxiliary power supply 6 and the detection circuit 8 with a protection circuit 7. The protection circuit 7 includes a switch, a fuse, a relay, a sensor, and a delay element, which is a loop used to prevent unstable factors such as electrical faults, short circuits, overloads, overvoltage, overcurrent, and overheating from affecting the circuit effect and causing equipment damage. It can ensure the safety and reliability of the equipment and the system, and avoid equipment damage, system crashes, and even casualties caused by electrical problems.

[0036] As used in the specification and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in names as a way to distinguish components, but use the difference in the functions of components as the criterion for distinction. As mentioned throughout the specification and claims, the term "comprising" is an open-ended term, so it should be interpreted as "including but not limited to". "Substantially" means within an acceptable error range. Those skilled in the art can solve technical problems within a certain error range and basically achieve the technical effect.

[0037] It should be noted that the term "including", "comprising", or any other variant thereof is intended to cover non-exclusive inclusion, so that a commodity or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such a commodity or system. Without further limitations, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the commodity or system including the element.

[0038] The above description shows and describes several preferred embodiments of the present invention. However, as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications, and environments, and can be changed within the scope of the inventive concept described herein through the above teachings or the technology or knowledge in related fields. And the changes and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should all be within the protection scope of the appended claims of the present invention.

Claims

1. A high-frequency switching power supply, comprising a main circuit (100) and a main control circuit (200) that are electrically connected, characterized in that, The main circuit (100) includes an input filter (1), a power supply filter (2), an inverter circuit (3), and an output power supply filter (4), and the main control circuit (200) includes an auxiliary power supply (6), a control circuit (5), and a detection circuit (8); The auxiliary power supply (6), the inverter circuit (3), and the output power supply filter (4) are all communicatively connected to the control circuit (5); The input filter (1) is electrically connected to the power supply filter (2) through a rectifier bridge. The power supply filter (2) includes an inductor L1 and a power transistor Q1. The inverter circuit (3) includes power transistors Q2, Q3, Q4, and Q5. The inverter circuit (3) is electrically connected to the output power supply filter (4) through a high-frequency transformer T1. A rectifier diode D1 and a rectifier diode D2 are arranged in parallel on the output power supply filter (4). A capacitor C3 is arranged in parallel with the rectifier diode D1, and a capacitor C4 is arranged in parallel with the rectifier diode D2. Ferrite beads are added to the input and output power lines, and the power lines are close to the ground wire.

2. The high-frequency switching power supply according to claim 1, wherein: A capacitor C1 is arranged in parallel with the power transistor Q1. The output terminal of the rectifier bridge is connected to a diode D3 through the inductor L1. The inductor L1 is arranged in parallel with the power transistor Q1, and a capacitor C5 is electrically connected to the diode D3.

3. The high-frequency switching power supply according to claim 1, wherein: The power transistor Q2 and the power transistor Q3 are arranged in parallel, and the power transistor Q4 and the power transistor Q5 are arranged in parallel. A capacitor C2 is arranged between the inverter circuit (3) and the high-frequency transformer T1.

4. A high-frequency switching power supply according to claim 1, characterized in that: A resistor R1 is arranged in series with the capacitor C3, a resistor R2 is arranged in series with the capacitor C4, and after the rectifier diodes D1 and D2 are connected in parallel, they are electrically connected to a resistor R3 through a high-frequency transformer T2.

5. A high-frequency switching power supply according to claim 1, characterized in that: The control circuit (5) includes a capacitor C7 and a diode D4 arranged in parallel. One side of the diode D4 is connected to a capacitor C6 and a resistor RL in parallel through an inductor L3; A switch K is electrically connected between the capacitor C7 and the diode D4.

6. The high-frequency switching power supply according to claim 1, characterized in that: The detection circuit (8) includes an ammeter, a voltmeter, an oscilloscope, and a logic analyzer.

7. A high-frequency switching power supply according to claim 1, characterized in that: A protection circuit (7) is electrically connected between the auxiliary power supply (6) and the detection circuit (8). The protection circuit (7) includes a switch, a fuse, a relay, a sensor, and a delay element.

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