TW202418733A - Power converter - Google Patents

Abstract

A power converter includes a primary-side rectifying/filtering circuit, an AC-DC converter, a DC/DC converter, a primary-side controller, a secondary-side rectification controller, and a secondary-side feedback controller. The primary-side rectifying/filtering circuit receives an input voltage, and rectifies and filters the input voltage into an adjusted input voltage. The AC-DC converter receives the adjusted input voltage. The primary-side controller provides a first control signal to control the AC-DC converter to convert the adjusted input voltage into a DC input voltage, and provides a second control signal to control the DC-DC converter. The secondary-side rectification controller provides a third control signal to control the DC-DC converter to convert the DC input voltage into a conversion voltage to supply power to a load based on a gain condition. The secondary-side feedback controller receives a power demand signal provided by the load to control the primary-side controller and the secondary-side rectification controller.

Description

Power Converter

The present invention relates to a power converter, and more particularly to a power converter that can be operated in a half-bridge or full-bridge circuit topology to provide multiple sets of output voltages of different magnitudes.

When the power is greater than 100 watts, power products usually choose the PFC+LLC topology. The main reason is that LLC has the characteristic of zero-voltage switching, which allows power products to operate at a higher frequency, thereby shrinking the magnetic components and reducing the size of the product.

The structure of PFC as the first stage and LLC as the second stage is a very common power supply design structure. However, in response to the continuous advancement of technology, the voltages required for 3C products are different, and therefore power product specifications with different output voltages have become more and more popular. However, since the LLC's best operating point for efficiency is the resonant frequency point, a stable input voltage and a stable output voltage must be maintained at this resonant frequency point, so LLC is usually not the best solution under a single output voltage.

Therefore, how to design a power converter to solve the problems and technical bottlenecks existing in the prior art is an important topic studied by the inventors of this case.

The purpose of the present invention is to provide a power converter to solve the problems of the prior art.

To achieve the above-mentioned purpose, the power converter proposed by the present invention includes a primary-side rectifying and filtering circuit, an AC-to-DC converter, a DC-to-DC converter, a primary-side controller, a secondary-side rectifying controller, and a secondary-side feedback controller. The primary-side rectifying and filtering circuit receives an input voltage, and rectifies and filters the input voltage to output an adjusted input voltage. The AC-to-DC converter is coupled to the primary-side rectifying and filtering circuit, and receives the adjusted input voltage. The DC-to-DC converter is coupled to the AC-to-DC converter. The primary-side controller is coupled to the AC-to-DC converter and the DC-to-DC converter, provides a first control signal to control the AC-to-DC converter to convert the adjusted input voltage into a DC input voltage, and provides a second control signal to control the DC-to-DC converter. The secondary side rectifier controller is coupled to the DC to DC converter, and provides a third control signal to control the DC to DC converter to convert the DC input voltage into a conversion voltage based on a gain condition to supply power to the load. The secondary side feedback controller is coupled to the primary side controller and the secondary side rectifier controller, and the secondary side feedback controller receives a load power supply demand signal provided by the load to control the operation of the primary side controller and the secondary side rectifier controller.

In one embodiment, the secondary-side feedback controller provides a feedback control signal including an AC/DC feedback control signal and a DC/DC feedback control signal to the primary-side controller, and provides a rectification control signal to the secondary-side rectification controller. The primary-side controller controls the AC/DC converter according to the AC/DC feedback control signal, controls the DC/DC converter according to the DC/DC feedback control signal, and controls the secondary-side rectification controller and adjusts the gain condition according to the rectification control signal.

In one embodiment, the DC-to-DC converter includes a primary-side isolation circuit and a secondary-side isolation circuit. The primary-side isolation circuit is coupled to the AC-to-DC converter and the primary-side controller to receive a second control signal and a DC input voltage. The secondary-side isolation circuit is coupled to the secondary-side rectifier controller to isolate and convert the DC input voltage.

In one embodiment, the primary side isolation circuit includes a bridge switching circuit and a resonant circuit, and the secondary side isolation circuit includes a bridge synchronous rectification circuit and a buck conversion circuit.

In one embodiment, the bridge switching circuit includes an upper switch and a lower switch. The first end of the upper switch is coupled to the AC-DC converter. The first end of the lower switch is coupled to the second end of the upper switch and the resonant circuit. The primary side controller provides a second control signal to control the upper switch and the lower switch.

In one embodiment, the bridge synchronous rectifier circuit includes a first switch, a second switch, a third switch, and a fourth switch; a first main resonant inductor and a second main resonant inductor; and a first auxiliary resonant inductor and a second auxiliary resonant inductor. The first end of the first auxiliary resonant inductor is coupled to the second end of the first switch, and the second end of the first auxiliary resonant inductor is coupled to the first end of the second switch and the second end of the first main resonant inductor; the first end of the second auxiliary resonant inductor is coupled to the second end of the third switch, and the second end of the second auxiliary resonant inductor is coupled to the first end of the fourth switch and the first end of the second main resonant inductor; the first end of the first main resonant inductor is coupled to the second end of the second main resonant inductor. The first end of the third switch is coupled to the first end of the first switch and the buck-type conversion circuit; the second end of the fourth switch is coupled to the second end of the second switch and the buck-type conversion circuit. The secondary-side rectifier controller provides a third control signal to control the first switch, the second switch, the third switch and the fourth switch.

In one embodiment, the bridge synchronous rectification circuit further includes a first capacitor and a second capacitor. The first end of the first capacitor is coupled to the third switch. The first end of the second capacitor is coupled to the second end of the first capacitor, and the second end of the second capacitor is coupled to the fourth switch.

In one embodiment, the buck converter circuit includes a fifth switch, a sixth switch, a diode, an inductor, and a capacitor. The first end of the fifth switch is coupled to the first end of the third switch. The first end of the sixth switch is coupled between the first end of the first main resonant inductor and the second end of the second main resonant inductor, and the second end of the sixth switch is coupled to the second end of the fifth switch. The cathode of the diode is coupled to the second end of the fifth switch and the second end of the sixth switch. The first end of the inductor is coupled to the cathode of the diode. The first end of the capacitor is coupled to the second end of the inductor, and the second end of the capacitor is coupled to the anode of the diode and the second end of the fourth switch.

In one embodiment, when the conversion voltage is the first voltage, the first switch and the third switch are turned off, and the second switch and the fourth switch are switched on to excite the first main resonant inductor or the second main resonant inductor.

In one embodiment, when the second switch is turned on, a first magnetic excitation path is formed, including the second switch, the first main resonant inductor, and the buck-type conversion circuit, and the first main resonant inductor is excited. When the fourth switch is turned on, a second magnetic excitation path is formed, including the fourth switch, the second main resonant inductor, and the buck-type conversion circuit, and the second main resonant inductor is excited.

In one embodiment, when the conversion voltage is the first voltage, the second switch and the fourth switch are turned off, and the first switch and the third switch are switched on to excite the first main resonant inductor or the second main resonant inductor.

In one embodiment, when the first switch is turned on, a third magnetic excitation path is formed, including the first switch, the first main resonant inductor and the buck-type conversion circuit, and the first main resonant inductor is excited. When the third switch is turned on, a fourth magnetic excitation path is formed, including the third switch, the second main resonant inductor and the buck-type conversion circuit, and the second main resonant inductor is excited.

In one embodiment, when the conversion voltage is the second voltage, the first switch and the fourth switch are turned on and off at the same time, the second switch and the third switch are turned on and off at the same time, and the first switch and the second switch are switched on and off to excite the first main resonant inductor and the second main resonant inductor.

In one embodiment, when the first switch and the fourth switch are turned on at the same time, a first magnetic excitation path is formed, including the first switch, the first auxiliary resonant inductor, the first main resonant inductor, the second main resonant inductor, the fourth switch, and the buck converter circuit. When the second switch and the third switch are turned on at the same time, a second magnetic excitation path is formed, including the second switch, the first main resonant inductor, the second main resonant inductor, the second auxiliary resonant inductor, the third switch, and the buck converter circuit.

In one embodiment, the output voltage of the power converter is adjusted by increasing the operating frequency of the primary-side isolation circuit to be greater than the resonance frequency.

In one embodiment, the output voltage of the power converter is adjusted by reducing the voltage of the front-stage power factor correction circuit.

In one embodiment, when the conversion voltage is less than the first voltage, the fifth switch and the sixth switch conduct the buck conversion circuit.

In one embodiment, when the conversion voltage is less than the second voltage, the fifth switch and the sixth switch conduct the buck conversion circuit.

In one embodiment, a buck converter circuit is used to convert the conversion voltage into a DC output voltage.

In one embodiment, the conversion voltage is stepped down into a DC output voltage of different voltage magnitudes by controlling the duty cycle of the fifth switch or the duty cycle of the sixth switch.

The proposed power converter can be operated in a half-bridge or full-bridge circuit topology to flexibly provide multiple sets of output voltages of different magnitudes.

In order to further understand the technology, means and effects adopted by the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention. It is believed that the purpose, features and characteristics of the present invention can be understood in depth and in detail. However, the attached drawings are only provided for reference and explanation, and are not used to limit the present invention.

The technical content and detailed description of the present invention are described as follows with reference to the accompanying drawings.

Please refer to FIG. 1 and FIG. 2, which are respectively the block diagram and detailed block diagram of the power converter of the present invention. The power converter with buck-boost conversion includes a primary-side rectifying and filtering circuit 1, an AC-to-DC converter 2, a DC-to-DC converter 3, a primary-side controller 4, a secondary-side rectifying controller 5, and a secondary-side feedback controller 6.

The primary-side rectifying and filtering circuit 1 receives the input voltage V _IN , and rectifies and filters the input voltage V _IN to output the regulated input voltage V _INRF . Specifically, the primary-side rectifying and filtering circuit 1 comprises a primary-side rectifying circuit and a primary-side filtering circuit (not shown). The primary-side rectifying circuit is used to rectify the input voltage V _IN . The primary-side filtering circuit is used to filter the rectified input voltage to output the regulated input voltage V _INRF to the AC-DC converter 2 .

The AC-to-DC converter 2 is coupled to the primary-side rectifying and filtering circuit 1 , and receives the regulated input voltage V _INRF outputted by the primary-side rectifying and filtering circuit 1 .

The DC-to-DC converter 3 is coupled to the AC-to-DC converter 2. Specifically, as shown in FIG. 3 and FIG. 4, they are circuit diagrams of the DC-to-DC converter of the present invention. The DC-to-DC converter 3 includes a primary-side isolation circuit 31 and a secondary-side isolation circuit 32. The primary-side isolation circuit 31 is coupled to the AC-to-DC converter 2 and the primary-side controller 4 to receive the second control signal _SC2 and the DC input voltage V _INDC provided by the primary-side controller 4. The secondary-side isolation circuit 32 is coupled to the secondary-side rectifier controller 5 to isolate and convert the DC input voltage V _INDC .

The primary-side isolation circuit 31 includes a bridge switching circuit 311 and a resonant circuit 312. The bridge switching circuit 311 includes an upper switch _QH and a lower switch _QL . A first end of the upper switch _QH is coupled to the AC-DC converter 2. A first end of the lower switch _QL is coupled to a second end of the upper switch _QH and the resonant circuit 312. The primary-side controller 4 provides a second control signal _SC2 to control the upper switch _QH and the lower switch _QL .

The secondary side isolation circuit 32 includes a bridge type synchronous rectification circuit 321 and a buck type conversion circuit 322. The bridge type synchronous rectification circuit 321 includes a first switch _Q1 , a second switch _Q2 , a third switch _Q3 , a fourth switch _Q4 , a first main resonant inductor _W11 , a second main resonant inductor _W12 , a first auxiliary resonant inductor _W21 and a second auxiliary resonant inductor _W22 . The first main resonant inductor _W11 , the second main resonant inductor _W12 and the first auxiliary resonant inductor _W21 and the second auxiliary resonant inductor _W22 are respectively implemented by the main winding and the auxiliary winding of the same inductive device (such as a transformer). Therefore, the voltage magnitudes of the first main resonant inductor W ₁₁ , the second main resonant inductor W ₁₂ , the first auxiliary resonant inductor W ₂₁ , and the second auxiliary resonant inductor W ₂₂ are proportional to the corresponding winding turns ratio.

The first end of the first auxiliary resonant inductor W ₂₁ is coupled to the second end of the first switch Q ₁ , and the second end of the first auxiliary resonant inductor W ₂₁ is coupled to the first end of the second switch Q ₂ and the second end of the first main resonant inductor W _11. The first end of the second auxiliary resonant inductor W ₂₂ is coupled to the second end of the third switch Q ₃ , and the second end of the second auxiliary resonant inductor W ₂₂ is coupled to the first end of the fourth switch Q ₄ and the first end of the second main resonant inductor W _12. The first end of the first main resonant inductor W ₁₁ is coupled to the second end of the second main resonant inductor W ₁₂ . In this embodiment, the first ends of the first main resonant inductor W ₁₁ , the second main resonant inductor W ₁₂ , the first auxiliary resonant inductor W ₂₁ , and the second auxiliary resonant inductor W ₂₂ are all marked ends, and the second ends of the first main resonant inductor W ₁₁ , the second main resonant inductor W ₁₂ , the first auxiliary resonant inductor W ₂₁ , and the second auxiliary resonant inductor W ₂₂ are all non-marked ends, but this is not intended to limit the present invention.

A first terminal of the third switch _Q3 is coupled to a first terminal of the first switch _Q1 and the buck converter circuit 322. A second terminal of the fourth switch _Q4 is coupled to a second terminal of the second switch _Q2 and the buck converter circuit 322. The secondary-side rectifier controller 5 provides a third control signal _SC3 to control the first switch _Q1 , the second switch _Q2 , the third switch _Q3 and the fourth switch _Q4 .

The bridge synchronous rectifier circuit 321 further includes a first capacitor _C1 and a second capacitor _C2 . The first end of the first capacitor _C1 is coupled to the first end of the third switch _Q3 and the first end of the first switch _Q1 . The first end of the second capacitor _C2 is coupled to the second end of the first capacitor _C1 , and the first end of the first main resonant inductor _W11 and the second end of the second main resonant inductor _W12 (i.e., the common end of the first main resonant inductor _W11 and the second main resonant inductor _W12 ). The second end of the second capacitor _C2 is coupled to the second end of the fourth switch _Q4 and the second end of the second switch _Q2 .

The buck converter circuit 322 is used to convert the conversion voltage V _CON into a DC output voltage V _OUTDC . The buck converter circuit 322 includes a fifth switch Q ₅ , a sixth switch Q ₆ , a diode D, an inductor L, and a capacitor C. The first end of the fifth switch Q ₅ is coupled to the first end of the third switch Q ₃ and the first end of the first capacitor C ₁ . The first end of the sixth switch Q ₆ is coupled to the first end of the first main resonant inductor W ₁₁ and the second end of the second main resonant inductor W ₁₂ ; the second end of the sixth switch Q ₆ is coupled to the second end of the fifth switch Q ₅ . The cathode of the diode D is coupled to the second end of the fifth switch Q ₅ and the second end of the sixth switch Q ₆ . The first end of the inductor L is coupled to the cathode of the diode D. A first end of the capacitor C is coupled to a second end of the inductor L, and a second end of the capacitor C is coupled to an anode of the diode D and a second end of the fourth switch _Q4 . In one embodiment, the sixth switch _Q6 can be implemented by back-to-back semiconductor elements, but the present invention is not limited thereto.

The primary-side controller 4 is coupled to the AC-DC converter 2 and the DC-DC converter 3 , provides a first control signal S _C1 to control the AC-DC converter 2 to convert and adjust the input voltage V _INRF into a DC input voltage V _INDC , and provides a second control signal S _C2 to control the DC-DC converter 3 .

The secondary-side rectifier controller 5 is coupled to the DC-DC converter 3 and provides a third control signal _SC3 to control the DC-DC converter 3 to convert the DC input voltage V _INDC into a conversion voltage V _CON based on a gain condition to supply power to the load 7 .

The secondary-side feedback controller 6 is coupled to the primary-side controller 4 and the secondary-side rectifier controller 5. The secondary-side feedback controller 6 receives a load power demand signal S _LP provided by the load 7 to control the operations of the primary-side controller 4 and the secondary-side rectifier controller 5. Specifically, the secondary-side feedback controller 6 provides a feedback control signal including an AC/DC feedback control signal S _CAD and a DC/DC feedback control signal S _CDD to the primary-side controller 4, and provides a rectifier control signal S _CSR to the secondary-side rectifier controller 5.

The primary-side controller 4 controls the AC-DC converter 2 according to the AC-DC feedback control signal S _CAD , controls the DC-DC converter 3 according to the DC-DC feedback control signal S _CDD , and controls the secondary-side rectifier controller 5 and adjusts the gain condition according to the rectifier control signal S _CSR .

When the bridge synchronous rectification circuit 321 is in half-bridge operation, the conversion voltage V _CON is a first voltage, such as but not limited to 20 volts, and the third control signal _SC3 controls the first switch Q ₁ and the third switch Q ₃ to be turned off, and controls the second switch Q ₂ and the fourth switch Q ₄ to be switched on and off, thereby exciting the first main resonant inductor W ₁₁ or the second main resonant inductor W _12. In this embodiment, when the second switch Q ₂ is turned on, a first magnetic excitation path is formed including the second switch Q ₂ , the first main resonant inductor W ₁₁ and the buck conversion circuit 322, thereby exciting the first main resonant inductor W ₁₁ . When the fourth switch _Q4 is turned on, a second magnetic excitation path is formed including the fourth switch _Q4 , the second main resonant inductor _W12 and the buck converter circuit 322, thereby exciting the second main resonant inductor _W12 .

The symmetrical circuit operation is that when the conversion voltage V _CON is the first voltage, the third control signal _SC3 controls the second switch Q ₂ and the fourth switch Q ₄ to be turned off, and controls the first switch Q ₁ and the third switch Q ₃ to be switched on and off, thereby exciting the first main resonant inductor W ₁₁ or the second main resonant inductor W _12. In this embodiment, when the first switch Q ₁ is turned on, a third magnetic excitation path is formed including the first switch Q ₁ , the first main resonant inductor W ₁₁ and the buck conversion circuit 322, thereby exciting the first main resonant inductor W ₁₁ . When the third switch _Q3 is turned on, a fourth magnetic excitation path is formed including the third switch _Q3 , the second main resonant inductor _W12 and the buck converter circuit 322, thereby exciting the second main resonant inductor _W12 .

When the conversion voltage V _CON is less than the first voltage (i.e., less than 20V), the fifth switch Q ₅ and the sixth switch Q ₆ turn on the buck conversion circuit 322. Specifically, by controlling the duty cycle of the fifth switch Q ₅ or the duty cycle of the sixth switch Q ₆ , the conversion voltage V _CON is stepped down into DC output voltages V _OUTDC of different voltages to provide multiple sets of output voltages of different magnitudes.

However, in the full-bridge operation that requires a voltage doubling output, when there are only the first main resonant inductor _W11 and the second main resonant inductor _W12 (that is, without the first auxiliary resonant inductor _W21 and the second auxiliary resonant inductor _W22 ), the output voltage has a fixed multiple (for example, 2 times) of the input voltage. Therefore, if a relationship between the output voltage and the input voltage that is not a fixed multiple is to be achieved, for example, the input voltage is 20 volts, and an output voltage of 48 volts is to be output, it is necessary to increase the input voltage of the PFC (power factor correction circuit) of the front stage (for example, from 400 volts to 480 volts) so that an output voltage of 48 volts is provided through a 2-fold voltage gain. However, the voltage raised by the pre-stage PFC will require the size of the bulk capacitor to be increased, which is not conducive to the design of system miniaturization.

Therefore, the present invention further optimizes the circuit design by using the first auxiliary resonant inductor W ₂₁ and the second auxiliary resonant inductor W _22. More specifically, the purpose of the present invention is achieved by designing the coil turns ratio of the first main resonant inductor W ₁₁ , the second main resonant inductor W ₁₂ , the first auxiliary resonant inductor W ₂₁ and the second auxiliary resonant inductor W ₂₂ .

For example, but not limiting the present invention, the turns ratio of the first main resonant inductor _W11 , the second main resonant inductor _W12 , the first auxiliary resonant inductor _W21 , and the second auxiliary resonant inductor _W22 is designed to be 2:2:1:1. Therefore, under the full-bridge operation (i.e., the voltage doubled output is required), the voltage of the first main resonant inductor _W11 (i.e., the voltage across the two ends of the first main resonant inductor _W11 , the same below) can be obtained to be 20 volts (referred to as the first voltage), the voltage of the second main resonant inductor _W12 is 20 volts (referred to as the second voltage), and the voltage of the first auxiliary resonant inductor W11 is 20 volts (referred to as the second voltage). The voltage of _W21 is 10V (referred to as the third voltage), and the voltage of the second auxiliary resonant inductor _W22 is 10V (referred to as the fourth voltage). In the full-bridge operation when the second switch _Q2 and the third switch _Q3 are turned on, the sum of the voltages across the first capacitor _C1 and the second capacitor _C2 is 50V (i.e., the sum of the first voltage, the second voltage, and the fourth voltage). Similarly, in the full-bridge operation when the first switch _Q1 and the fourth switch _Q4 are turned on, the sum of the voltages across the first capacitor _C1 and the second capacitor _C2 is 50V (i.e., the sum of the first voltage, the second voltage, and the third voltage).

In the aforementioned output voltage state, the 50 volt output voltage can be corrected to 48 volts in two ways. The first way is to increase the operating frequency of the LLC circuit (i.e., the primary isolation circuit 31) to be greater than the resonant frequency, which will slightly reduce the gain and achieve an output voltage of 48 volts. In this way, it is no longer necessary to increase the voltage of the front-stage PFC, so there is no need to select a larger capacitor. The second method: Without increasing the operating frequency of the LLC circuit, the voltage of the front-stage PFC can be lowered (for example, from 400 volts to 380 volts) to directly achieve an output voltage of 48 volts, which means that the first voltage and the second voltage are slightly less than 20 volts, and the third voltage and the fourth voltage are slightly less than 10 volts, so that the sum of the first voltage, the second voltage and the third voltage or the sum of the first voltage, the second voltage and the fourth voltage directly reaches 48 volts. This not only reduces the volume of the large capacitor, which is beneficial to the design of system miniaturization, but also improves the power conversion efficiency.

In addition, the present invention can further make the output voltage meet the requirements of a wider voltage range through the design of different coil turn ratios of the first main resonant inductor W ₁₁ , the second main resonant inductor W ₁₂ , the first auxiliary resonant inductor W ₂₁ , and the second auxiliary resonant inductor W ₂₂ .

That is, when the bridge synchronous rectifier circuit 321 is in full-bridge operation, it is used to provide a voltage doubler output. At this time, the conversion voltage V _CON is a second voltage, such as but not limited to 48 volts or 36 volts. The third control signal _SC3 controls the first switch _Q1 and the fourth switch _Q4 to be turned on and off at the same time, and controls the second switch _Q2 and the third switch _Q3 to be turned on and off at the same time, and controls the first switch _Q1 and the second switch _Q2 to switch on and off mutually, so as to excite the first main resonant inductor _W11 and the second main resonant inductor _W12 , as well as the first auxiliary resonant inductor _W21 or the second auxiliary resonant inductor _W22 . Specifically, when the first switch _Q1 and the fourth switch _Q4 are turned on at the same time, the first magnetic excitation path includes the first switch _Q1 , the first auxiliary resonant inductor _W21 , the first main resonant inductor _W11 , the second main resonant inductor _W12 , the fourth switch _Q4 and the buck converter circuit 322, so the first main resonant inductor _W11 , the second main resonant inductor _W12 and the first auxiliary resonant inductor _W21 are excited at the same time. When the second switch _Q2 and the third switch _Q3 are turned on at the same time, the second magnetic excitation path includes the second switch _Q2 , the first main resonant inductor _W11 , the second main resonant inductor _W12 , the second auxiliary resonant inductor _W22 , the third switch _Q3 and the buck converter circuit 322, so the first main resonant inductor _W11 , the second main resonant inductor _W12 and the second auxiliary resonant inductor _W22 are excited at the same time.

When the conversion voltage V _CON is less than the second voltage (i.e., less than 48V or 36V), the fifth switch Q ₅ and the sixth switch Q ₆ turn on the buck conversion circuit 322. By controlling the duty cycle of the fifth switch Q ₅ or the duty cycle of the sixth switch Q ₆ , the conversion voltage V _CON is stepped down into DC output voltages V _OUTDC of different voltages to provide multiple sets of output voltages of different magnitudes.

The power converter proposed by the present invention can be operated in a half-bridge or full-bridge circuit topology to flexibly provide multiple sets of output voltages of different magnitudes. Furthermore, by designing the coil turns ratio of the first main resonant inductor W ₁₁ , the second main resonant inductor W ₁₂ , the first auxiliary resonant inductor W ₂₁ , and the second auxiliary resonant inductor W ₂₂ , the output voltage can meet the requirements of a wider range of voltages.

The above description is only a detailed description and drawings of the preferred specific embodiments of the present invention, but the features of the present invention are not limited thereto, and are not used to limit the present invention. The entire scope of the present invention shall be subject to the following patent application scope. All embodiments that conform to the spirit of the patent application scope of the present invention and its similar variations shall be included in the scope of the present invention. Any changes or modifications that can be easily thought of by anyone familiar with the art within the field of the present invention can be covered by the following patent scope of this case.

1: Primary side rectifier filter circuit 2: AC to DC converter 3: DC to DC converter 4: Primary side controller 5: Secondary side rectifier controller 6: Secondary side feedback controller 7: Load 31: Primary side isolation circuit 32: Secondary side isolation circuit 311: Bridge switching circuit 312: Resonance circuit 321: Bridge synchronous rectifier circuit 322: Buck converter circuit Q _H : Upper switch Q _L : Lower switch Q ₁ : First switch Q ₂ : Second switch Q ₃ : Third switch Q ₄ : Fourth switch Q ₅ : Fifth switch Q ₆ : Sixth switch W ₁₁ : First main resonant inductor W ₁₂ : Second main resonant inductor W ₂₁ : First auxiliary resonant inductor W ₂₂ : Second auxiliary resonant inductor C ₁ : First capacitor C ₂ : Second capacitor D : Diode L : Inductor C : Capacitor V _IN : Input voltage V _INRF : Adjusted input voltage V _INDC : DC input voltage V _CON : Conversion voltage V _OUTDC : DC output voltage S _C1 : First control signal S _C2 : Second control signal S _C3 : Third control signal S _LP : Load power demand signal S _CSR : Rectification control signal S _CAD : AC/DC feedback control signal S _CDD : DC/DC feedback control signal

FIG1 is a block diagram of the power converter of the present invention.

FIG. 2 is a detailed block diagram of the power converter of the present invention.

FIG. 3 and FIG. 4 are circuit diagrams of the DC-to-DC converter of the present invention.

1: Primary side rectification and filtering circuit

2: AC to DC converter

3: DC to DC converter

4: Primary side controller

5: Secondary side rectifier controller

6: Secondary side feedback controller

7: Load

V _IN : Input voltage

V _INRF : Adjust input voltage

V _INDC : DC input voltage

V _OUTDC : DC output voltage

S _C1 : First control signal

S _C2 : Second control signal

S _C3 : The third control signal

S _LP : Load power demand signal

S _CSR : Rectification control signal

S _CAD : AC/DC feedback control signal

S _CDD : DC feedback control signal

Claims (20)

A power converter includes: a primary-side rectifying and filtering circuit, receiving an input voltage, rectifying and filtering the input voltage to output an adjusted input voltage; an AC-to-DC converter, coupled to the primary-side rectifying and filtering circuit, and receiving the adjusted input voltage; a DC-to-DC converter, coupled to the AC-to-DC converter; a primary-side controller, coupled to the AC-to-DC converter and the DC-to-DC converter, providing a first control signal to control the AC-to-DC converter to convert the adjusted input voltage into a DC input voltage, and providing a second control signal to control the DC-to-DC converter; A secondary-side rectifier controller is coupled to the DC-DC converter and provides a third control signal to control the DC-DC converter to convert the DC input voltage into a conversion voltage based on a gain condition to supply power to a load; and A secondary-side feedback controller is coupled to the primary-side controller and the secondary-side rectifier controller. The secondary-side feedback controller receives a load power supply demand signal provided by the load to control the operation of the primary-side controller and the secondary-side rectifier controller. A power converter as described in claim 1, wherein the secondary-side feedback controller provides a feedback control signal including an AC/DC feedback control signal and a DC feedback control signal to the primary-side controller, and provides a rectification control signal to the secondary-side rectification controller; wherein the primary-side controller controls the AC/DC converter according to the AC/DC feedback control signal, controls the DC/DC converter according to the DC feedback control signal, and controls the secondary-side rectification controller and adjusts the gain condition according to the rectification control signal. A power converter as described in claim 1, wherein the DC-to-DC converter comprises: a primary-side isolation circuit coupled to the AC-to-DC converter and the primary-side controller for receiving the second control signal and the DC input voltage; and a secondary-side isolation circuit coupled to the secondary-side rectifier controller for isolating and converting the DC input voltage. A power converter as described in claim 3, wherein the primary-side isolation circuit includes a bridge switching circuit and a resonance circuit; and the secondary-side isolation circuit includes a bridge synchronous rectification circuit and a buck conversion circuit. A power converter as described in claim 4, wherein the bridge switching circuit comprises: an upper switch, a first end of the upper switch is coupled to the AC-DC converter; and a lower switch, a first end of the lower switch is coupled to a second end of the upper switch and the resonant circuit; wherein the primary-side controller provides the second control signal to control the upper switch and the lower switch. A power converter as described in claim 4, wherein the bridge synchronous rectification circuit comprises: a first switch, a second switch, a third switch and a fourth switch; a first main resonant inductor and a second main resonant inductor; and a first auxiliary resonant inductor and a second auxiliary resonant inductor; A first end of the first auxiliary resonant inductor is coupled to a second end of the first switch, a second end of the first auxiliary resonant inductor is coupled to a first end of the second switch and a second end of the first main resonant inductor; a first end of the second auxiliary resonant inductor is coupled to a second end of the third switch, a second end of the second auxiliary resonant inductor is coupled to a first end of the fourth switch and a first end of the second main resonant inductor; a first end of the first main resonant inductor is coupled to a second end of the second main resonant inductor; A first end of the third switch is coupled to a first end of the first switch and the buck-type conversion circuit; a second end of the fourth switch is coupled to a second end of the second switch and the buck-type conversion circuit; The secondary-side rectifier controller provides the third control signal to control the first switch, the second switch, the third switch and the fourth switch. A power converter as described in claim 6, wherein the bridge synchronous rectification circuit further comprises: a first capacitor, a first end of which is coupled to the third switch; and a second capacitor, a first end of which is coupled to a second end of the first capacitor, and a second end of which is coupled to the fourth switch. A power converter as described in claim 6, wherein the buck conversion circuit comprises: a fifth switch, a first end of the fifth switch coupled to the first end of the third switch; a sixth switch, a first end of the sixth switch coupled to the first end of the first main resonant inductor and the second end of the second main resonant inductor, and a second end of the sixth switch coupled to a second end of the fifth switch; a diode, a cathode of the diode coupled to the second end of the fifth switch and the second end of the sixth switch; an inductor, a first end of the inductor coupled to the cathode of the diode; and a capacitor, a first end of the capacitor coupled to a second end of the inductor, and a second end of the capacitor coupled to an anode of the diode and a second end of the fourth switch. A power converter as described in claim 6, wherein when the conversion voltage is a first voltage, the first switch and the third switch are turned off, and the second switch and the fourth switch are switched on to excite the first main resonant inductor or the second main resonant inductor. A power converter as described in claim 9, wherein when the second switch is turned on, a first magnetic excitation path is formed including the second switch, the first main resonant inductor and the buck-type conversion circuit, and the first main resonant inductor is excited; when the fourth switch is turned on, a second magnetic excitation path is formed including the fourth switch, the second main resonant inductor and the buck-type conversion circuit, and the second main resonant inductor is excited. A power converter as described in claim 6, wherein when the conversion voltage is a first voltage, the second switch and the fourth switch are turned off, and the first switch and the third switch are switched on to excite the first main resonant inductor or the second main resonant inductor. A power converter as described in claim 11, wherein when the first switch is turned on, a third magnetic excitation path is formed including the first switch, the first main resonant inductor and the buck-type conversion circuit, and the first main resonant inductor is excited; when the third switch is turned on, a fourth magnetic excitation path is formed including the third switch, the second main resonant inductor and the buck-type conversion circuit, and the second main resonant inductor is excited. A power converter as described in claim 6, wherein when the conversion voltage is a second voltage, the first switch and the fourth switch are turned on and off at the same time, the second switch and the third switch are turned on and off at the same time, and the first switch and the second switch are switched on and off alternately to excite the first main resonant inductor and the second main resonant inductor and the first auxiliary resonant inductor or the second auxiliary resonant inductor. A power converter as described in claim 12, wherein when the first switch and the fourth switch are turned on at the same time, a first magnetic excitation path is formed including the first switch, the first auxiliary resonant inductor, the first main resonant inductor, the second main resonant inductor, the fourth switch and the buck-type conversion circuit; when the second switch and the third switch are turned on at the same time, a second magnetic excitation path is formed including the second switch, the first main resonant inductor, the second main resonant inductor, the second auxiliary resonant inductor, the third switch and the buck-type conversion circuit. A power converter as described in claim 6, wherein the output voltage of the power converter is adjusted by increasing the operating frequency of the primary-side isolation circuit to be greater than the resonant frequency. A power converter as described in claim 6, wherein the output voltage of the power converter is adjusted by reducing the voltage of a front-stage power factor correction circuit. A power converter as described in claim 9, wherein when the conversion voltage is less than the first voltage, the fifth switch and the sixth switch turn on the step-down conversion circuit. A power converter as described in claim 13, wherein when the conversion voltage is less than the second voltage, the fifth switch and the sixth switch turn on the step-down conversion circuit. A power converter as described in claim 6, wherein the step-down conversion circuit is used to convert the conversion voltage into a DC output voltage. A power converter as described in claim 19, wherein the conversion voltage is stepped down to the DC output voltage of different voltage magnitude by controlling a duty cycle of the fifth switch or a duty cycle of the sixth switch.

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