A high power factor power adapter circuit

Abstract

The utility model discloses a power adapter circuit of high power factor, it includes rectifier circuit unit, filter circuit unit, PFC circuit unit, LLC conversion circuit unit and controller, rectifier circuit unit and filter circuit unit electricity are connected, PFC circuit unit includes first resistance, second resistance, first boost inductance, first diode and first field effect tube, and the first end of second resistance and the grid of first field effect tube electricity are connected, and the second end of second resistance is connected with the controller. The first end of first boost inductance is grounded, and the second end of first boost inductance is electrically connected with the controller, and the third end of first boost inductance is electrically connected with filter circuit unit, and the fourth end of first boost inductance is electrically connected with the drain of first field effect tube. The anode of first diode and the drain of first field effect tube electricity are connected, and the cathode of first diode and LLC conversion circuit unit electricity are connected. The utility model improves power factor and reduces harmonic distortion, reduces power grid transmission loss.

Description

Technical Field

[0001] This utility model relates to the field of power adapter technology, and in particular to a power adapter circuit with a high power factor. Background Technology

[0002] With the development of technology, electronic products have also flourished and have permeated all aspects of life. Among electronic products, power adapters convert the voltage from the AC mains to the voltage supplied to the electronic device, enabling it to obtain the appropriate electrical energy. Power adapters play a crucial role in supplying voltage and current to electronic products.

[0003] Traditional power adapter circuits employ a rectifier bridge and filter capacitor structure, resulting in input current spikes and pulses that are severely distorted and contain numerous harmonics. To address this, those skilled in the art have introduced Power Factor Correction (PFC) circuits into power adapter circuits. PFC circuits control the input current waveform to approximate a sine wave and align it with the voltage, thereby reducing total harmonic distortion, improving the power factor, reducing interference to the power grid, and improving electromagnetic compatibility. However, existing power adapter circuits still suffer from low power factors, resulting in high reactive power from the grid and significant transmission losses. Utility Model Content

[0004] The technical problem solved by this utility model is to provide a power adapter circuit with a high power factor that can reduce power grid transmission losses.

[0005] This utility model provides a high power factor power adapter circuit, including a rectifier circuit unit, a filter circuit unit, a PFC circuit unit, an LLC converter circuit unit, and a controller. The rectifier circuit unit is electrically connected to the filter circuit unit. The PFC circuit unit includes a first resistor, a second resistor, a first boost inductor, a first diode, and a first field-effect transistor. The first end of the first resistor is electrically connected to the source of the first field-effect transistor, and the second end of the first resistor is electrically connected to the gate of the first field-effect transistor. The first end of the second resistor is electrically connected to the gate of the first field-effect transistor, and the second end of the second resistor is electrically connected to the controller.

[0006] The first terminal of the first boost inductor is grounded, the second terminal of the first boost inductor is electrically connected to the controller, the third terminal of the first boost inductor is electrically connected to the filter circuit unit, and the fourth terminal of the first boost inductor is electrically connected to the drain of the first field-effect transistor; the anode of the first diode is electrically connected to the drain of the first field-effect transistor, and the cathode of the first diode is electrically connected to the LLC converter circuit unit.

[0007] In one embodiment, the PFC circuit unit further includes a second diode connected in parallel with the first diode.

[0008] In one embodiment, the PFC circuit unit further includes a third resistor, a first end of which is electrically connected to a second end of the second resistor, and the second end of the third resistor is electrically connected to the controller; the second resistor is electrically connected to the controller through the third resistor.

[0009] In one embodiment, the PFC circuit unit further includes a third diode, the anode of which is electrically connected to a first terminal of the second diode, and the cathode of which is electrically connected to a second terminal of the second resistor.

[0010] In one embodiment, the PFC circuit unit further includes a first capacitor and a fourth resistor, wherein a first terminal of the first capacitor is electrically connected to a first terminal of the fourth resistor, and a second terminal of the first capacitor is grounded; a first terminal of the fourth resistor is electrically connected to the rectifier circuit unit, and a second terminal of the fourth resistor is electrically connected to the controller.

[0011] In one embodiment, the PFC circuit unit further includes a fifth resistor, the first end of which is electrically connected to the rectifier circuit unit, and the second end of which is electrically connected to the first end of the fourth resistor; the fourth resistor is electrically connected to the rectifier circuit unit through the fifth resistor.

[0012] In one embodiment, the PFC circuit unit further includes a second capacitor, the first end of which is electrically connected to the second end of the fourth resistor, and the second end of the second capacitor is grounded.

[0013] In one embodiment, the PFC circuit unit further includes a third capacitor and a fourth diode, wherein a first terminal of the third capacitor is electrically connected to the cathode of the fourth diode, and a second terminal of the third capacitor is grounded; the anode of the fourth diode is electrically connected to the second terminal of the fourth resistor.

[0014] In one embodiment, the PFC circuit unit further includes a sixth resistor and a seventh resistor, the first end of the sixth resistor being electrically connected to the second end of the third capacitor, the second end of the sixth resistor being electrically connected to the first end of the seventh resistor, and the second end of the seventh resistor being grounded.

[0015] In one embodiment, the PFC circuit unit further includes an eighth resistor, the first end of which is electrically connected to the second end of the first boost inductor, and the second end of which is electrically connected to the controller; the second end of the first boost inductor is electrically connected to the controller through the eighth resistor.

[0016] This invention has the following beneficial effects: Through the cooperation of the first resistor, second resistor, first boost inductor, first diode, and first field-effect transistor in the PFC circuit unit, when the first field-effect transistor in the PFC circuit is turned on, the input voltage is directly applied across the first boost inductor, and the current of the first boost inductor increases linearly, storing electrical energy in the first boost inductor in the form of magnetic energy; when the first field-effect transistor is turned off, the first boost inductor releases the stored energy and supplies power to the load through the first diode. At this time, the voltage of the first inductor is superimposed on the input voltage, realizing the boost function. In other words, by storing and releasing energy, the waveform of the input current is adjusted to be in phase with the input voltage, thereby improving the power factor and reducing harmonic distortion, and reducing power grid transmission losses. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the high power factor power adapter circuit of this utility model.

[0018] Figure 2 This is a circuit diagram showing the coordination between the controller, filter circuit unit, and PFC circuit unit of the high power factor power adapter circuit of this utility model. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, embodiments of the present invention and the various features thereof can be combined with each other, all of which are within the protection scope of the present invention.

[0020] Please see Figure 1 and Figure 2 This utility model provides a high power factor power adapter circuit, including a rectifier circuit unit 1, a filter circuit unit 2, a PFC circuit unit 3, an LLC converter circuit unit 4, a transformer 5, and a controller 6. The rectifier circuit unit 1 and the filter circuit unit 2 are electrically connected and are used to rectify the power from the grid. The filter circuit unit 2 is used to filter the power output from the rectifier circuit unit 1, and includes a fourth capacitor C4, a fifth capacitor C5, and a filter inductor L3. The fourth capacitor C4 and the fifth capacitor C5 are respectively connected to the two ends of the filter inductor L3.

[0021] PFC circuit unit 3 includes a first resistor R1, a second resistor R2, a first boost inductor L1, a first diode D1, and a first field-effect transistor T1. The first terminal of the first resistor R1 is electrically connected to the source of the first field-effect transistor T1, and the second terminal of the first resistor R1 is electrically connected to the gate of the first field-effect transistor T1. The first terminal of the second resistor R2 is electrically connected to the gate of the first field-effect transistor T1, and the second terminal of the second resistor R2 is electrically connected to the controller 6.

[0022] The first terminal of the first boost inductor L1 is grounded, the second terminal of the first boost inductor L1 is electrically connected to the controller 6, the third terminal of the first boost inductor L1 is electrically connected to the filter circuit unit 2, and the fourth terminal of the first boost inductor L1 is electrically connected to the drain of the first field-effect transistor T1. The anode of the first diode D1 is electrically connected to the drain of the first field-effect transistor T1, and the cathode of the first diode D1 is electrically connected to the LLC converter circuit unit 4. The controller 6 can be a microcontroller.

[0023] PFC circuit unit 3 also includes a second diode D2, which is connected in parallel with the first diode D1. The inductor's power is output to LLC converter circuit unit 4 through the diode. The parallel connection of the second diode D2 and the first diode D1 shares the total current, with each diode only handling a portion. This improves the overall current carrying capacity of the circuit and prevents burnout due to excessive current in a single diode. Furthermore, if one of the parallel diodes fails (e.g., becomes open-circuited), the other diodes can continue to operate, preventing a complete circuit interruption and improving circuit reliability and stability. The parallel connection of two diodes also distributes power loss, resulting in less heat generated by each diode, which helps improve heat dissipation, lowers the operating temperature of the devices, and extends their lifespan.

[0024] PFC circuit unit 3 also includes a third resistor R3. The first end of the third resistor R3 is electrically connected to the second end of the second resistor R2, and the second end of the third resistor R3 is electrically connected to the controller 6. The second resistor R2 is electrically connected to the controller 6 through the third resistor R3. When the gate voltage of the first field-effect transistor T1 changes rapidly, voltage spikes may occur. Therefore, by setting the third resistor R3, the controller 6 can be protected.

[0025] PFC circuit unit 3 also includes a third diode D3. The anode of the third diode D3 is electrically connected to the first terminal of the second diode D2, and the cathode of the third diode D3 is electrically connected to the second terminal of the second resistor R2. When the gate of the first field-effect transistor T1 needs to be discharged quickly to turn off the first field-effect transistor T1, the third diode D3 can provide a low-impedance discharge path, accelerate the release of gate charge, and thus speed up the turn-off speed of the first field-effect transistor T1.

[0026] PFC circuit unit 3 also includes a first capacitor C1, a fourth resistor R4, and a fifth resistor R5. The first terminal of the first capacitor C1 is electrically connected to the first terminal of the fourth resistor R4, and the second terminal of the first capacitor C1 is grounded. The first terminal of the fourth resistor R4 is electrically connected to the rectifier circuit unit 1, and the second terminal of the fourth resistor R4 is electrically connected to the controller 6. The first terminal of the fifth resistor R5 is electrically connected to the rectifier circuit unit 1, and the second terminal of the fifth resistor R5 is electrically connected to the first terminal of the fourth resistor R4. The fourth resistor R4 is electrically connected to the rectifier circuit unit 1 through the fifth resistor R5.

[0027] PFC circuit unit 3 also includes a second capacitor C2, a third capacitor C3, and a fourth diode D4. The first terminal of the second capacitor C2 is electrically connected to the second terminal of the fourth resistor R4, and the second terminal of the second capacitor C2 is grounded. The first terminal of the third capacitor C3 is electrically connected to the cathode of the fourth diode D4, and the second terminal of the third capacitor C3 is grounded. The anode of the fourth diode D4 is electrically connected to the second terminal of the fourth resistor R4.

[0028] PFC circuit unit 3 also includes a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8. The first terminal of the sixth resistor R6 is electrically connected to the second terminal of the third capacitor C3, and the second terminal of the sixth resistor R6 is electrically connected to the first terminal of the seventh resistor R7. The second terminal of the seventh resistor R7 is grounded. The first terminal of the eighth resistor R8 is electrically connected to the second terminal of the first boost inductor L1, and the second terminal of the eighth resistor R8 is electrically connected to the controller 6. The second terminal of the first boost inductor L1 is electrically connected to the controller 6 through the eighth resistor R8. Furthermore, PFC circuit unit 3 in this embodiment also includes a second boost inductor L2, a second field-effect transistor T2, a fifth diode D5, a sixth diode D6, a seventh diode D7, a ninth resistor R9, a tenth resistor R10, and an eleventh resistor R11. During operation, the controller 6 controls the first field-effect transistor T1 and the second field-effect transistor T2 to work alternately.

[0029] In summary, this invention, through the coordination of the first resistor R1, the second resistor R2, the first boost inductor L1, the first diode D1, and the first field-effect transistor T1 in the PFC circuit unit 3, allows the input voltage to be directly applied across the first boost inductor L1 when the first field-effect transistor T1 is turned on. The current in the first boost inductor L1 increases linearly, and electrical energy is stored in the first boost inductor L1 in the form of magnetic energy. When the first field-effect transistor T1 is turned off, the first boost inductor L1 releases the stored energy and supplies power to the load through the first diode D1. At this time, the voltage of the first inductor is superimposed on the input voltage, achieving the boost function. In other words, by storing and releasing energy, the input current waveform is adjusted to be in phase with the input voltage, thereby improving the power factor, reducing harmonic distortion, and lowering power grid transmission losses.

[0030] The high power factor power adapter circuit provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. Furthermore, those skilled in the art will recognize that, based on the idea of ​​this utility model, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification is only an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model and should not be construed as a limitation of this utility model.

Claims

1. A high power factor power adapter circuit, characterized in that, The device includes a rectifier circuit unit, a filter circuit unit, a PFC circuit unit, an LLC converter circuit unit, and a controller. The rectifier circuit unit is electrically connected to the filter circuit unit. The PFC circuit unit includes a first resistor, a second resistor, a first boost inductor, a first diode, and a first field-effect transistor. The first terminal of the first resistor is electrically connected to the source of the first field-effect transistor, and the second terminal of the first resistor is electrically connected to the gate of the first field-effect transistor. The first terminal of the second resistor is electrically connected to the gate of the first field-effect transistor, and the second terminal of the second resistor is electrically connected to the controller. The first terminal of the first boost inductor is grounded, the second terminal of the first boost inductor is electrically connected to the controller, the third terminal of the first boost inductor is electrically connected to the filter circuit unit, and the fourth terminal of the first boost inductor is electrically connected to the drain of the first field-effect transistor; the anode of the first diode is electrically connected to the drain of the first field-effect transistor, and the cathode of the first diode is electrically connected to the LLC converter circuit unit.

2. The high power factor power adapter circuit as described in claim 1, characterized in that, The PFC circuit unit also includes a second diode, which is connected in parallel with the first diode.

3. The high power factor power adapter circuit as described in claim 1 or 2, characterized in that, The PFC circuit unit further includes a third resistor, the first end of which is electrically connected to the second end of the second resistor, and the second end of which is electrically connected to the controller; the second resistor is electrically connected to the controller through the third resistor.

4. The high power factor power adapter circuit as described in claim 2, characterized in that, The PFC circuit unit further includes a third diode, the anode of which is electrically connected to the first terminal of the second diode, and the cathode of which is electrically connected to the second terminal of the second resistor.

5. The high power factor power adapter circuit as described in claim 1 or 2, characterized in that, The PFC circuit unit further includes a first capacitor and a fourth resistor. The first terminal of the first capacitor is electrically connected to the first terminal of the fourth resistor, and the second terminal of the first capacitor is grounded. The first terminal of the fourth resistor is electrically connected to the rectifier circuit unit, and the second terminal of the fourth resistor is electrically connected to the controller.

6. The high power factor power adapter circuit as described in claim 5, characterized in that, The PFC circuit unit further includes a fifth resistor, the first end of which is electrically connected to the rectifier circuit unit, and the second end of which is electrically connected to the first end of the fourth resistor; the fourth resistor is electrically connected to the rectifier circuit unit through the fifth resistor.

7. The high power factor power adapter circuit as described in claim 5, characterized in that, The PFC circuit unit further includes a second capacitor, the first end of which is electrically connected to the second end of the fourth resistor, and the second end of the second capacitor is grounded.

8. The high power factor power adapter circuit as described in claim 5, characterized in that, The PFC circuit unit further includes a third capacitor and a fourth diode. The first terminal of the third capacitor is electrically connected to the cathode of the fourth diode, and the second terminal of the third capacitor is grounded. The anode of the fourth diode is electrically connected to the second terminal of the fourth resistor.

9. The high power factor power adapter circuit as described in claim 8, characterized in that, The PFC circuit unit further includes a sixth resistor and a seventh resistor. The first end of the sixth resistor is electrically connected to the second end of the third capacitor, the second end of the sixth resistor is electrically connected to the first end of the seventh resistor, and the second end of the seventh resistor is grounded.

10. The high power factor power adapter circuit as described in claim 1, characterized in that, The PFC circuit unit further includes an eighth resistor, the first end of which is electrically connected to the second end of the first boost inductor, and the second end of which is electrically connected to the controller; the second end of the first boost inductor is electrically connected to the controller through the eighth resistor.

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