Power conversion circuit and power adapter

Abstract

According to the power conversion circuit and the power adapter provided by the utility model, two-stage differential-mode filtering is formed by the input differential-mode filtering unit, the first-stage filtering inductance unit, the second-stage filtering inductance unit and the output differential-mode filtering unit, so that internal and external differential-mode interference can be filtered out; a first-stage common-mode filtering unit, a first-stage filtering inductance unit, a second-stage common-mode filtering unit, a second-stage filtering inductance unit and a third-stage common-mode filtering unit form three-stage common-mode filtering, and the three-stage common-mode filtering is used for filtering internal and external common-mode interference. And stable direct-current power is provided for the power end of the electronic equipment.

Description

Technical Field

[0001] This utility model relates to the field of power electronics, and in particular to a power conversion circuit and a power adapter. Background Technology

[0002] With the rapid development of electronic products and the increasing demands for the safety performance of electronic devices, power adapters need to meet the optimization indicators of AC power conduction and radiation. However, in order to improve market competitiveness, some companies reduce the configuration of the filtering circuit, resulting in low radiation margin and poor anti-interference ability of the power adapter.

[0003] In view of the above, this application is hereby submitted. Utility Model Content

[0004] This utility model discloses a power conversion circuit and a power adapter, which aims to solve the problems of low radiation margin and poor anti-interference ability of existing power adapters.

[0005] The first embodiment of this utility model provides a power conversion circuit, including: an input differential mode filter unit, a first-stage common mode filter unit, a first-stage filter inductor unit, a second-stage common mode filter unit, a second-stage filter inductor unit, a third-stage common mode filter unit, an output differential mode filter unit, and a rectification unit;

[0006] The input differential-mode filter unit and the first-stage common-mode filter unit are connected to the input terminal of the AC power supply. The first side of the first-stage filter inductor unit is connected in parallel to the first-stage common-mode filter unit. The second side of the first-stage filter inductor unit is connected in series with the first side of the second-stage filter inductor unit. The second-stage common-mode filter unit is configured between the first-stage filter inductor unit and the second-stage filter inductor unit. The second side of the second-stage filter inductor unit is electrically connected to the input terminal of the rectifier unit through the third-stage common-mode filter unit and the output differential-mode filter unit. The output terminal of the rectifier unit is used to connect to the power supply terminal of the electronic device.

[0007] Preferably, the input differential mode filtering unit includes a first capacitor and a second capacitor, and the first-stage common mode filtering unit includes a third capacitor;

[0008] The third capacitor is connected in parallel between the N line and L line of the AC power supply. The N line of the AC power supply is grounded through the first capacitor, and the L line of the AC power supply is grounded through the second capacitor.

[0009] Preferably, the first-stage common-mode filter unit includes a first inductor and a second inductor;

[0010] The first terminals of the first inductor and the second inductor are electrically connected to the first and second terminals of the third capacitor, respectively, and the second terminals of the first inductor and the second inductor are electrically connected to both sides of the secondary common-mode filter unit, respectively.

[0011] Preferably, the secondary common-mode filter unit includes a fourth capacitor;

[0012] The second terminals of the first inductor and the second inductor are electrically connected to the first terminal and the second terminal of the fourth capacitor, respectively.

[0013] Preferably, the secondary common-mode filter unit includes a third inductor and a fourth inductor;

[0014] The first ends of the third inductor and the fourth inductor are electrically connected to the first and second ends of the fourth capacitor, respectively, and the second ends of the third inductor and the fourth inductor are electrically connected to both sides of the three-stage common-mode filter unit, respectively.

[0015] Preferably, the output differential mode filter unit includes a fifth capacitor and a sixth capacitor, and the three-stage common mode filter unit includes a seventh capacitor;

[0016] The second ends of the third inductor and the fourth inductor are electrically connected to the two sides of the seventh capacitor, respectively. The second end of the third inductor is grounded through the fifth capacitor, and the second end of the fourth inductor is grounded through the sixth capacitor.

[0017] Preferably, the rectifier unit includes a rectifier bridge and a DC filter circuit;

[0018] The input terminal of the rectifier bridge is electrically connected to the two ends of the seventh capacitor, and the output of the rectifier bridge is electrically connected to the power supply terminal of the electronic device through the DC filter circuit.

[0019] The second embodiment of this utility model provides a power adapter, characterized in that it includes a power conversion circuit as described in any one of the above claims.

[0020] Based on the power conversion circuit and power adapter provided by this utility model, a two-stage differential mode filter is formed by an input differential mode filter unit, a first-stage filter inductor unit, a second-stage filter inductor unit, and an output differential mode filter unit to filter out internal and external differential mode interference. A three-stage common mode filter is formed by a first-stage common mode filter unit, a first-stage filter inductor unit, a second-stage common mode filter unit, a second-stage filter inductor unit, and a third-stage common mode filter unit to filter out internal and external common mode interference. The rectifier unit converts the filtered AC signal into a DC signal to provide a stable DC power supply to the power supply terminal of the electronic device. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a power conversion circuit provided by this utility model. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0023] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0024] This utility model discloses a power conversion circuit and a power adapter, which aims to solve the problems of low radiation margin and poor anti-interference ability of existing power adapters.

[0025] Please see Figure 1 The first embodiment of this utility model provides a power conversion circuit, including: an input differential mode filter unit, a first-stage common mode filter unit, a first-stage filter inductor unit 1, a second-stage common mode filter unit, a second-stage filter inductor unit 2, a third-stage common mode filter unit, an output differential mode filter unit, and a rectification unit;

[0026] The input differential mode filter unit and the first-stage common mode filter unit are connected to the input terminal of the AC power supply. The first side of the first-stage filter inductor unit 1 is connected in parallel to the first-stage common mode filter unit. The second side of the first-stage filter inductor unit 1 is connected in series with the first side of the second-stage filter inductor unit 2. The second-stage common mode filter unit is configured between the first-stage filter inductor unit 1 and the second-stage filter inductor unit 2. The second side of the second-stage filter inductor unit 2 is electrically connected to the input terminal of the rectifier unit through the third-stage common mode filter unit and the output differential mode filter unit. The output terminal of the rectifier unit is used to connect to the power supply terminal of the electronic device.

[0027] It should be noted that in this embodiment, the input differential-mode filtering unit and the first-stage common-mode filtering unit are jointly configured at the input end of the AC power supply to initially filter out differential-mode interference and common-mode interference in the input power supply. Further, in this embodiment, the input differential-mode filtering unit includes a first capacitor C1 and a second capacitor C2, and the first-stage common-mode filtering unit includes a third capacitor C3. The third capacitor C3 is connected in parallel between the N-line and L-line of the AC power supply. The N-line of the AC power supply is grounded through the first capacitor C1, and the L-line of the AC power supply is grounded through the second capacitor C2. These three capacitors are used to suppress common-mode interference, i.e., high-frequency noise signals propagating simultaneously through the L-line and N-line. The configuration of the first capacitor C1 and the second capacitor C2 is designed to optimize for differential-mode noise in the input power supply, i.e., voltage fluctuations existing between the L-line and N-line. This efficiently converts differential-mode noise into a discharge current to ground, thereby significantly reducing its propagation possibility in the circuit and ensuring a cleaner current signal entering subsequent circuits. The presence of the third capacitor C3 provides a low-impedance path, allowing common-mode noise to be quickly guided to ground, preventing it from interfering with the normal operation of the circuit and peripheral devices. Simultaneously, the third capacitor C3 also stabilizes the input power waveform, mitigating irregularities in the input waveform to some extent.

[0028] In this embodiment, the first-stage common-mode filter unit may include a first inductor L1 and a second inductor L2;

[0029] The first terminals of the first inductor L1 and the second inductor L2 are electrically connected to the first and second terminals of the third capacitor C3, respectively, and the second terminals of the first inductor L1 and the second inductor L2 are electrically connected to both sides of the secondary common-mode filter unit.

[0030] It should be noted that the function of the first inductor L1 and the second inductor L2 is to provide a high-impedance path for common-mode noise, thereby preventing its propagation in the circuit. The first inductor L1 and the second inductor L2, together with the third capacitor C3, form a classic common-mode filter network, exhibiting excellent filtering characteristics within a specific frequency range. When common-mode interference carried by the input signal enters the circuit, the third capacitor C3 guides the noise portion to ground, while the first inductor L1 and the second inductor L2 further restrict the flow of high-frequency noise on the L and N lines. This not only effectively protects subsequent parts of the circuit from common-mode noise but also reduces electromagnetic interference to external devices.

[0031] In this embodiment, the secondary common-mode filter unit may include a fourth capacitor C4;

[0032] The second ends of the first inductor L1 and the second inductor L2 are electrically connected to the first and second ends of the fourth capacitor C4, respectively.

[0033] It should be noted that, in this embodiment, the introduction of the fourth capacitor C4 into the circuit forms a more complete common-mode noise filtering network. The presence of the fourth capacitor C4 enables a more refined resonance characteristic between the inductor and capacitor, thereby further improving the suppression capability of common-mode noise in a specific frequency band. Secondly, the fourth capacitor C4 provides a low-impedance path for high-frequency common-mode noise, allowing the remaining common-mode interference entering the secondary common-mode filtering unit to be quickly guided to ground. The common-mode interference is further significantly weakened at this level. The step-by-step interference suppression mechanism not only improves the frequency band covered by the filtering effect but also enhances the reliability of the power conversion circuit in complex electromagnetic environments.

[0034] In this embodiment, the secondary common-mode filter unit includes a third inductor L3 and a fourth inductor L4;

[0035] The first ends of the third inductor L3 and the fourth inductor L4 are electrically connected to the first and second ends of the fourth capacitor C4, respectively, and the second ends of the third inductor L3 and the fourth inductor L4 are electrically connected to both sides of the three-stage common-mode filter unit.

[0036] It should be noted that the combination of the fourth capacitor C4 and the preceding inductor creates a stronger resonance effect. When high-frequency common-mode noise enters the second-stage common-mode filter unit after passing through the preceding filter, the third inductor L3 and the fourth inductor L4 further limit the propagation of high-frequency interference signals through their high impedance characteristics, preventing this noise from entering subsequent circuits and thus effectively improving the overall filtering effect.

[0037] In this embodiment, the output differential mode filtering unit includes a fifth capacitor C5 and a sixth capacitor C6, and the three-stage common mode filtering unit includes a seventh capacitor C7.

[0038] The second ends of the third inductor L3 and the fourth inductor L4 are electrically connected to the two sides of the seventh capacitor C7, respectively. The second end of the third inductor L3 is grounded through the fifth capacitor C5, and the second end of the fourth inductor L4 is grounded through the sixth capacitor C6.

[0039] It should be noted that the introduction of the seventh capacitor C7 not only enhances the common-mode filtering effect but also further optimizes the interference suppression capability in the high-frequency band. Through its synergistic effect with the third inductor L3 and the fourth inductor L4, the seventh capacitor C7 can guide more common-mode noise to ground, significantly reducing its propagation in the circuit. This ensures that residual common-mode interference after the power signal has undergone multiple stages of filtering is effectively controlled. Furthermore, the fifth capacitor C5 and the sixth capacitor C6 of the output differential-mode filter unit further improve the filtering function of the entire circuit. The second terminal of the third inductor L3 is grounded through the fifth capacitor C5, and the second terminal of the fourth inductor L4 is grounded through the sixth capacitor C6. This allows residual differential-mode interference to be quickly consumed, thereby achieving the final purification of the power signal. The addition of the fifth capacitor C5 and the sixth capacitor C6 forms a reliable differential-mode filter network at the output signal end, effectively reducing the amplitude of differential-mode noise.

[0040] In this embodiment, the rectifier unit includes a rectifier bridge 3 and a DC filter circuit 4;

[0041] The input terminal of the rectifier bridge 3 is electrically connected to the two ends of the seventh capacitor C7, and the output of the rectifier bridge 3 is electrically connected to the power supply terminal of the electronic device through the DC filter circuit 4.

[0042] It should be noted that the input terminal of the rectifier bridge 3 is directly electrically connected to the two ends of the seventh capacitor C7. As part of a three-stage common-mode filter unit, the seventh capacitor C7 further eliminates common-mode interference, providing a more stable input signal for the rectifier bridge 3. This effectively avoids the influence of common-mode noise on the rectification process, ensuring that the rectifier bridge 3 can efficiently convert AC power into a pulsating DC signal. The rectifier bridge 3 typically consists of multiple diodes, which can conduct different groups of diodes during the positive and negative half-cycles of the AC input, thereby achieving complete rectification functionality.

[0043] The output of rectifier bridge 3 is electrically connected to the power supply of the electronic equipment through DC filter circuit 4. DC filter circuit 4 smooths the rectified signal, eliminates pulsating components, and provides a more stable DC output signal. Especially under conditions of significant load variations, DC filter circuit 4 can maintain the stability of the output voltage.

[0044] The second embodiment of this utility model provides a power adapter, characterized in that it includes a power conversion circuit as described in any one of the above claims.

[0045] Based on the power conversion circuit and power adapter provided by this utility model, a two-stage differential mode filter is formed by an input differential mode filter unit, a first-stage filter inductor unit 1, a second-stage filter inductor unit 2, and an output differential mode filter unit to filter out internal and external differential mode interference. A three-stage common mode filter is formed by a first-stage common mode filter unit, a first-stage filter inductor unit 1, a second-stage common mode filter unit, a second-stage filter inductor unit 2, and a third-stage common mode filter unit to filter out internal and external common mode interference. The rectifier unit converts the filtered AC signal into a DC signal to provide a stable DC power supply to the power supply terminal of the electronic device.

[0046] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions that fall within the scope of this utility model's concept are protected by this utility model.

Claims

1. A power conversion circuit, characterized in that, include: The system includes an input differential-mode filter unit, a first-stage common-mode filter unit, a first-stage filter inductor unit, a second-stage common-mode filter unit, a second-stage filter inductor unit, a third-stage common-mode filter unit, an output differential-mode filter unit, and a rectification unit. The input differential-mode filter unit and the first-stage common-mode filter unit are connected to the input terminal of the AC power supply. The first side of the first-stage filter inductor unit is connected in parallel to the first-stage common-mode filter unit. The second side of the first-stage filter inductor unit is connected in series with the first side of the second-stage filter inductor unit. The second-stage common-mode filter unit is configured between the first-stage filter inductor unit and the second-stage filter inductor unit. The second side of the second-stage filter inductor unit is electrically connected to the input terminal of the rectifier unit through the third-stage common-mode filter unit and the output differential-mode filter unit. The output terminal of the rectifier unit is used to connect to the power supply terminal of the electronic device.

2. The power conversion circuit according to claim 1, characterized in that, The input differential mode filter unit includes a first capacitor and a second capacitor, and the first-stage common mode filter unit includes a third capacitor; The third capacitor is connected in parallel between the N line and L line of the AC power supply. The N line of the AC power supply is grounded through the first capacitor, and the L line of the AC power supply is grounded through the second capacitor.

3. The power conversion circuit according to claim 2, characterized in that, The first-stage common-mode filter unit includes a first inductor and a second inductor; The first terminals of the first inductor and the second inductor are electrically connected to the first and second terminals of the third capacitor, respectively, and the second terminals of the first inductor and the second inductor are electrically connected to both sides of the secondary common-mode filter unit, respectively.

4. A power conversion circuit according to claim 3, characterized in that, The secondary common-mode filter unit includes a fourth capacitor; The second terminals of the first inductor and the second inductor are electrically connected to the first terminal and the second terminal of the fourth capacitor, respectively.

5. A power conversion circuit according to claim 4, characterized in that, The secondary common-mode filter unit includes a third inductor and a fourth inductor; The first ends of the third inductor and the fourth inductor are electrically connected to the first and second ends of the fourth capacitor, respectively, and the second ends of the third inductor and the fourth inductor are electrically connected to both sides of the three-stage common-mode filter unit, respectively.

6. A power conversion circuit according to claim 5, characterized in that, The output differential mode filter unit includes a fifth capacitor and a sixth capacitor, and the three-stage common mode filter unit includes a seventh capacitor; The second ends of the third inductor and the fourth inductor are electrically connected to the two sides of the seventh capacitor, respectively. The second end of the third inductor is grounded through the fifth capacitor, and the second end of the fourth inductor is grounded through the sixth capacitor.

7. A power conversion circuit according to claim 6, characterized in that, The rectifier unit includes a rectifier bridge and a DC filter circuit; The input terminal of the rectifier bridge is electrically connected to the two ends of the seventh capacitor, and the output of the rectifier bridge is electrically connected to the power supply terminal of the electronic device through the DC filter circuit.

8. A power adapter, characterized in that, Includes a power conversion circuit as described in any one of claims 1 to 7.

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