TWI683513B - Power converter and control method - Google Patents

Abstract

The invention relates to a power converter with a resonant converter and its control method. The power converter includes an AC-DC converter and a DC-DC converter. The AC-DC converter converts the AC voltage to DC voltage. The input voltage of DC-DC converter is from the output of the AC-DC converter. The DC-DC converter includes a resonant converter. The real resonant frequency of the resonant converter is obtained from zero cross point detection and peak current detection of resonant current. To improve the efficiency, the AC-DC converter output voltage is regulated to control the switching frequency approximate or equal to the resonance frequency of resonant converter. This resonant frequency tracking control method deals with the issues caused by the resonant component tolerance which results in inaccurate calculation of resonant frequency and therefore the switching frequency cannot be operate at the resonant frequency.

The control method includes the control modes under steady state and transient conditions, respectively. For the control mode under steady state condition, the above-mentioned resonant frequency tracking to increase the efficiency. For the control mode under transient condition, the DC link voltage is kept constant while switching frequency is determined by the load condition to fast regulate the output voltage and improve the transient response.

Description

Power converter and its control method

The invention relates to a power converter with a resonant converter and its control method, in particular to a related technology that can detect the actual resonant frequency of the resonant converter and speed up its response speed.

A known power converter with a resonant tank converter is shown in FIG. 1, which includes an AC-to-DC converter 10 and a DC-to-DC converter. The DC-to-DC converter is composed of a resonant tank The converter is constituted by the AC-to-DC converter 10 inputted into an AC power source and converted into a high-voltage DC power source, and the high-voltage DC power source is converted into a low-voltage DC power source via a DC-DC converter with a resonant tank converter.

The DC-DC converter is composed of a converter 23 with a resonant tank. As shown in FIG. 1, it has a converter 23 with a resonant tank. It mainly includes a switching circuit 11, a primary resonant tank 12, and a transformer 13. 、A secondary side resonance tank 14 and a rectifier circuit 15. The input terminal of the switching circuit 11 is a high-voltage power supply and is connected to the primary resonance tank 12, the primary resonance tank 12 is connected to the transformer 13, and the transformer 13 is connected to the secondary resonance tank 14, and the two resonance tanks can obtain two resonances Frequency; and this resonance frequency is divided into two resonance frequencies, the first resonance frequency _fr is a higher frequency resonance frequency; the second resonance frequency f _m is a lower frequency resonance frequency.

The converter with a resonant tank uses frequency modulation to achieve voltage regulation; when the load becomes heavier, the frequency moves from high frequency to low frequency to adjust the voltage to achieve voltage regulation.

The switching frequency of the converter with a resonant tank operates at the first resonant frequency, which reduces the large switching loss and conduction loss caused by the converter operating in each area. When the switching frequency is close to the first resonant frequency, it has the characteristics of zero voltage switching And, when the power switch is closed, additional circulating current loss can be reduced in the resonant tank, and the switching loss at this time can also be reduced to improve the efficiency of the converter.

The technology for operating the resonant tank converter at the resonant frequency is described with a prior art (refer to Patent Document 1). For the first resonant frequency detection method, a switching frequency needs to be sent first to make the resonant current exhibit a sine wave. The switching frequency is the first resonant frequency. After learning the first resonant frequency, set this as the reference frequency to adjust the output voltage of the AC-to-DC converter, so that the switching frequency of the converter is maintained at the resonant frequency and the voltage regulation is reached. Overall power converter efficiency.

The technology with the resonant tank converter operating at the first resonant frequency is described with another prior art (refer to Patent Document 2). The first resonant frequency detection method detects the change of current on the line to adjust the switching frequency. The switching frequency is operated at the first resonance frequency, and the efficiency of the converter is improved.

【references】

Zih-Jie Su and Yen-Shin Lai, “On-line DC-link voltage control of LLC resonant converter for server power applications,” IEEE Conference Publications, Publication Year: 2014, pp.5422-5428.

TW I617126

The main object of the present invention is to provide a power converter including a resonant tank and a control method thereof, which detects the actual first resonant frequency according to the working state of the resonant tank converter, and then makes the switching frequency of the converter approach or equal to The actual first resonance frequency, thereby achieving an increase in efficiency.

In order to achieve the cost of the invention, the above-mentioned power converter that requires a resonant tank includes: an AC-to-DC converter with an AC power input, a DC power output and a control terminal; a DC-to-DC converter with A DC power input terminal, a DC power output terminal, a DC-DC converter controller, a resonance current zero-crossing point detection, and a resonance current peak detection. The resonant current zero-crossing point detection and peak detection are respectively connected with a controller with a resonant tank converter and a DC-DC converter to obtain a square wave voltage signal of a zero-crossing point detection and peak detection, respectively. Measure the rising edge of the two square wave voltages to calculate this period of time, knowing that this period of time is one quarter of the actual first resonance period, and then converted by the DC-DC converter controller into the actual first resonance frequency and the current To calculate the switching frequency of The control end of the DC converter to change the output voltage of the AC to DC converter, thereby controlling the switching frequency of the converter with a resonant tank.

The aforementioned square wave voltage signal is generated by the resonant current of the converter with a resonant tank through zero-crossing point detection and peak detection to generate two square wave voltage signals, and extract the rising edge of the two square wave voltage signals The time between, the actual first resonance period is obtained by online calculation, the actual first resonance period and the current switching period are calculated, and an adjustable AC to DC converter is generated by an adjustable voltage controller unit The reference value of the output voltage, and the switching frequency of the converter is controlled to be close to or equal to the first resonant frequency by adjusting the output voltage of the AC-to-DC converter to improve efficiency.

Another object of the present invention is to provide a faster response speed with a resonant frequency tracking function. When the DC-to-DC controller approaches the converter switching frequency close to or equal to the first resonant frequency, frequency modulation is no longer the traditional method. To achieve voltage stabilization, the output voltage of the AC-to-DC converter is adjusted to achieve a stable voltage at the output end of the DC-to-DC converter.

The aforementioned invention mainly performs mode control based on the error value output from the output voltage of the resonant converter to the controller. In the steady state, the error value is low. The mode control module makes the converter switching frequency approach or equal to the first resonance The frequency is the online resonant frequency tracking module; when the load changes, the error value is large, and the mode judgment module will judge that the frequency modulation module needs to be used to achieve fast voltage regulation, so as to improve the response speed of the output end.

In order to further understand the technology and effects of the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention to prove the purpose, features and characteristics of the present invention, which can be obtained in depth and specific For the sake of understanding, the attached drawings are provided for reference and explanation only, and are not intended to limit the present invention.

V _ac ‧‧‧ AC input voltage

Vbus‧‧‧AC to DC output voltage

S1‧‧‧ First power switch

S2‧‧‧second power switch

S3‧‧‧third power switch

S4‧‧‧The fourth power switch

S5‧‧‧ fifth power switch

S6‧‧‧ sixth power switch

S7‧‧‧ seventh power switch

S8‧‧‧Eighth power switch

Cr1‧‧‧primary resonance capacitor

Lr1‧‧‧primary resonance inductor

Cr2‧‧‧Secondary side resonance capacitor

Lr2‧‧‧secondary resonant inductor

Cr11‧‧‧ Primary resonance capacitor

Cr12‧‧‧primary second resonant capacitor

Cr21‧‧‧Second Side Resonance Capacitor

Cr22‧‧‧Second resonant capacitor on the secondary side

T‧‧‧Transformer

CT‧‧‧current detector

Vout‧‧‧Resonant converter output voltage

NP‧‧‧Transformer primary winding

Ns1‧‧‧Transformer secondary side first winding

Co‧‧‧ Output capacitance

Vout_FB‧‧‧Output voltage feedback

Vout_ref‧‧‧Output voltage feedback reference value

Vgs1~Vgs8 S1~S8 ‧‧‧Gate signal

t1‧‧‧Zero crossing point detection square wave voltage signal rising edge time

t2‧‧‧Peak detection square wave voltage signal rising edge time

Tr‧‧‧Resonance period

Ts‧‧‧ switching cycle

10‧‧‧AC to DC converter

11‧‧‧Switch circuit

12‧‧‧primary resonance tank

13‧‧‧Transformer

14‧‧‧Secondary side resonance tank

15‧‧‧Rectifier circuit

16‧‧‧Zero crossing detection

17‧‧‧ Online resonance frequency calculation unit

18‧‧‧Peak detection

19‧‧‧Gate signal generator

20‧‧‧AC to DC converter controller

21‧‧‧Adjustable voltage controller unit

22‧‧‧DC to DC converter controller

23‧‧‧With resonant tank converter

24‧‧‧Full bridge switching circuit

25‧‧‧The first primary resonance tank

26‧‧‧The first secondary side resonance tank

27‧‧‧Full bridge rectifier circuit

28‧‧‧The first converter with resonant tank

29‧‧‧ Half-bridge switching circuit

30‧‧‧Second primary resonance tank

31‧‧‧Second secondary resonance tank

32‧‧‧Half-bridge rectifier circuit

33‧‧‧The second converter with resonant tank

34‧‧‧Controller

35‧‧‧Online resonance frequency tracking module

36‧‧‧ Frequency Modulation Module

37‧‧‧Mode control module

Figure 1 is a circuit diagram of the power converter of the present invention; Figure 2 is a circuit diagram of another preferred embodiment of the power converter of the present invention; Figure 3 is a circuit diagram of another preferred embodiment of the power converter of the present invention Figure 4 is a block diagram of the adjustable voltage controller unit of the present invention; Figure 5 is an operation block diagram of another invention;

The technical content and detailed description of the present invention are explained as follows in conjunction with the drawings:

Please refer to FIG. 2 for a circuit diagram of the first preferred embodiment of the power converter of the present invention. It includes an AC-to-DC converter 10, a DC-to-DC converter having a first converter 28 with a resonant tank; wherein, the AC-to-DC converter has an AC input voltage V _ac , a DC output power source V _bus and an AC Controller 20 of the DC converter. Its structure is mainly converted from the AC input voltage of the AC input power supply end to the high-voltage DC voltage, and then output to the V _bus through the DC power output end.

In this embodiment, the DC-to-DC converter is the first converter with a resonant tank 28, which has a full-bridge switching circuit 24, the first primary resonant tank 25, a transformer 13, the first secondary side The resonant tank 26 has a DC-DC converter controller 22, a zero-crossing point detection 16, a peak detection 18, an online resonance frequency calculation unit 17, and a gate signal generator 19. The switching signals of the power switches S1 to S4 in the full-bridge switching circuit are generated and controlled by the gate signal generator 19, and the full-bridge switching circuit 24 is connected to the first-type primary resonance tank 25, and the primary-side resonance tank It includes a primary resonance inductance L _r1 , a primary resonance capacitance C _r1 and a magnetizing inductance L _m , the magnetizing inductance uses the magnetizing inductance L _m of the transformer 13; and the transformer 13 is connected to the first secondary Side resonance tank 26, the secondary side resonance tank includes a secondary side resonance inductance L _r2 and a secondary side resonance capacitor C _r2 , the first type secondary resonance tank 26 is connected to the full bridge of the converter Rectifier circuit 27.

In this embodiment, the current detector CT is used to capture the resonant current in the resonant tank and connect the zero crossing point detection 16 and the peak detection 18; and these two detections will generate two square wave voltage signals, at this time zero The rising edge of the square wave voltage signal generated by the crossover point detection 16 is t1, the rising edge of the square wave voltage signal generated by the peak detection 18 is t2, and then the time t1 and t2 are captured by the online resonance frequency calculation unit 17 and Do the calculation, and this period of time is a quarter of the actual first resonance period.

FIG. 4 shows a control block diagram after the actual resonance period T _r calculating unit 17 via the line that the resonant frequency, and the switching cycle time to do the calculation, the resulting value of the error enters a controller 34, and the amount of compensation out The original AC-to-DC converter output voltage reference value is calculated and passed to the AC-to-DC converter controller 20 to change the AC-to-DC converter output voltage, and the switching frequency of the resonant converter is modulated by adjusting the output voltage Approaching or equal to the first resonance frequency to achieve the effect of improving efficiency.

Please refer to FIG. 3 for a circuit diagram of a second preferred embodiment of the power converter of the present invention. In this embodiment, the DC-to-DC converter is composed of a second converter 33 with a resonant tank, which has a half-bridge switching circuit 29, a second primary resonant tank 30, a transformer 13, and a second two Secondary side resonant tank 31, half-bridge rectifier circuit 32, DC-DC converter controller 22, a zero-crossing point detection 16, a peak detection 18, an online resonance frequency calculation unit 17 and a gate signal generator 19. The switching signals of the power switches S1 and S2 in the half-bridge switching circuit 29 are generated and controlled by the gate signal generator 19, and the half-bridge switching circuit 29 is connected to the second type primary resonance tank 30, the second type The side resonance tank includes a primary resonance inductance L _r1 , a primary resonance capacitance Cr11, a primary resonance capacitance Cr12 and a magnetizing inductance L _m . The magnetizing inductance uses the excitation of the transformer 13 instead The inductance L _m ; and the transformer 13 is connected to the second secondary resonance tank 31, the second secondary resonance tank includes a secondary resonance inductor L _r2 , a secondary resonance capacitor Cr21, a The second-side secondary resonance capacitor Cr22 has a second-type secondary-side resonance tank 31 connected to the half-bridge rectifier circuit 32. Its operation state is the same as the first embodiment.

The aforementioned invention technology resonant frequency tracking is mainly used when the converter with a resonant tank operates in a steady state, and controls the switching frequency of the converter to make its operation approach or equal to the resonant frequency to improve efficiency; when the output load fluctuates, Because the switching frequency of the converter has been fixed and the frequency regulation can not be used to achieve voltage regulation, the output voltage of the AC to DC converter needs to be adjusted to achieve voltage regulation, and the response speed is relatively slow. This patent proposes another invention to solve the above-mentioned problems. The main purpose is to accelerate the transient response to rapid changes in load.

Please refer to Figure 5 for a block diagram of combining resonance frequency tracking and speeding up transient response speed, which includes an online resonance frequency tracking module 35, a frequency modulation module 36 and a mode control module 37, while the online resonance The frequency tracking module 35 is the above-mentioned invention of resonant frequency tracking technology.

It is mainly determined by the mode control module 37 in determining whether to switch between different modules. The mode control module subtracts the output voltage feedback of the converter with the resonant tank and the output voltage reference value, and obtains the output voltage error value. In the general steady state, the S switching variable in the mode control module is 0, indicating that the on-line resonance frequency tracking module 35 is being executed. When the output voltage error value is greater than the upper limit value of the error value, it indicates that the load is changing greatly The S switching variable will be 1 and the mode is switched to the frequency modulation module 36. The DC-to-DC converter controller 22 of the converter with a resonant tank uses the change in the switching frequency to achieve output voltage stability Pressure action; and when the load stops changing, the error value of the output voltage gradually becomes smaller and compared with the original lower limit value of the error value, if it is less than S, the switching variable will become 0, and return to the execution line resonance frequency tracking mode Group 35.

As can be seen from the above two inventions, when the resonant frequency tracking is stable for the power converter, the actual first resonant frequency will be affected by the error of the component with the resonant tank converter and the parasitic effects generated on the circuit, and operate at The actual first resonant frequency improves efficiency; in the transient response mode of load change, the control module uses mode switching to speed up the slower response speed caused by the resonant frequency tracking.

V _ac ‧‧‧ AC input voltage

10‧‧‧AC to DC converter

11‧‧‧Switch circuit

12‧‧‧primary resonance tank

13‧‧‧Transformer

14‧‧‧Secondary side resonance tank

15‧‧‧Rectifier circuit

16‧‧‧Zero crossing detection

17‧‧‧ Online resonance frequency calculation unit

18‧‧‧Peak detection

19‧‧‧Gate signal generator

20‧‧‧AC to DC converter controller

21‧‧‧Adjustable voltage controller unit

22‧‧‧AC to DC converter controller

23‧‧‧With resonant converter

V _bus ‧‧‧AC to DC output voltage

S1‧‧‧ First power switch

S2‧‧‧second power switch

S3‧‧‧third power switch

S4‧‧‧The fourth power switch

S5‧‧‧ fifth power switch

S6‧‧‧ sixth power switch

S7‧‧‧ seventh power switch

S8‧‧‧Eighth power switch

CT‧‧‧current detector

V _out ‧‧‧Resonant converter output voltage

N _P ‧‧‧ Primary winding of transformer

N _s1 ‧‧‧ transformer secondary winding

C _o ‧‧‧ output capacitance

T‧‧‧Transformer

V _gs1 ~V _gs8 S1~S8‧‧‧Gate signal

t ₁ ‧‧‧ Zero crossing point detection square wave voltage signal rising edge time point

t ₂ ‧‧‧ Peak detection square wave voltage signal rising edge time

T _r ‧‧‧ resonance period

T _s ‧‧‧ switching cycle

Claims (24)

A power converter includes: an AC to DC converter, including an AC power input terminal, a DC power output terminal, and an AC to DC control terminal, a DC to DC converter; it includes a switching circuit, according to the switching frequency A switch in a switch switching circuit to convert a DC voltage into an AC signal; a primary-side resonant tank, electrically connected to the switching circuit on the side, for receiving an AC signal to provide a resonant current; a transformer, which Electrically connected to a primary side resonant tank to provide energy to the secondary side; a secondary side resonant tank, electrically connected to a transformer to provide current to a rectifier circuit; a rectifier circuit, electrically connected to the secondary side resonant tank, It is used to rectify the AC signal output from the secondary side resonance tank and provide an output voltage; the DC-DC converter controller calculates the switching frequency required by the switching circuit according to the output voltage. The power converter as claimed in item 1 further includes a gate signal generator connected to a switch such as a DC-DC converter controller, a switching circuit, and a rectifier circuit. The DC-DC converter The controller calculates according to the change of the output voltage, and outputs the corresponding switching frequency to the gate signal generator to control the opening and closing of the switch. The power converter as claimed in item 1 has the function of resonant frequency tracking, which provides resonant current to a zero-crossing point detection and a peak detection. The zero-crossing point detection and peak detection can be provided separately The voltage signal is sent to an online resonance frequency calculation unit. The online resonance frequency calculation unit will provide a quarter of the actual first resonance period and output it to an adjustable voltage controller unit. Adjust the output voltage of the AC-to-DC converter so that the switching frequency operation of the DC-to-DC converter approaches or equals the first resonant frequency of the resonant converter. If the power converter described in item 3 is requested, the resonant frequency calculation on the line will capture the zero-crossing point detection voltage signal rising edge time and the peak detection voltage signal rising edge time. After calculating the two time points, define This period of time is a quarter of the actual first resonance period, and the first resonance frequency of the resonant converter can be obtained. As requested in the power converter described in item 3, after the online resonance frequency calculation unit provides a quarter of the actual first resonance period, the actual first resonance period and the actual switching period provided by the DC-DC converter controller are obtained , Provided to an adjustable voltage controller unit to calculate the difference and the output voltage value of the AC-DC converter to be adjusted, the output of the controller is provided to the control end of the AC-DC converter to adjust the AC-DC converter The output voltage of the DC to DC converter is controlled to approach or equal to the first resonant frequency of the resonant converter. According to the power converter described in item 5, the actual switching period obtained by the adjustable voltage controller unit is greater than the actual first resonance period, and the adjustable voltage controller unit will increase the Output voltage reference value to increase the switching frequency of the DC-DC converter. According to the power converter described in item 5, the actual switching period obtained by the adjustable voltage controller unit is less than the actual first resonance period, the adjustable The voltage controller unit will reduce the reference value of the output voltage of the original AC-to-DC converter to reduce the switching frequency of the DC-to-DC converter. The power converter as claimed in item 1 has a quick response function, and the above-mentioned resonance frequency tracking function is modularized, and the other module is a frequency modulation module, which is to detect the output voltage to adjust The function of switching frequency uses these two modules as the mode control, and this control is the mode control module. For the power converter described in item 8 of the request, the mode control decision is mainly calculated by the output voltage of the resonant converter and the reference value of the output voltage, and the output error value after the calculation is used to judge; in the steady state, the error value If it is less than a threshold value, it will work in the resonance frequency tracking module; when the error value is greater than another threshold value, the module will switch to the frequency modulation module to improve the response speed. The power converter described in items 1 to 9 is requested and has a fast response function. The DC-DC converter has a resonant tank converter, which has a switching circuit, a primary resonant tank, a transformer, a The secondary side resonance tank, a rectifier circuit, a DC-DC converter controller and a gate signal generator. The switching signal of the power switch in the switching circuit is generated and controlled by the gate signal generator, and the switching circuit is connected to the primary resonance tank, and the primary resonance tank is connected to the transformer, and the transformer is connected to the secondary resonance tank. The side resonance tank is connected to the rectifier circuit of the DC-DC converter. The power converter as described in items 1 to 9 is requested and has a fast response function. The DC-DC converter has a resonant tank converter and has a switching power supply And the switching circuit is composed of a full-bridge switching circuit, a half-bridge switching circuit, or a third-order switching circuit; it has a primary resonance tank, and the primary resonance tank contains a resonance capacitor, resonance inductance, or magnetizing inductance. It can be composed of different series and parallel methods; it has a secondary side resonant tank, and this secondary side resonant tank can contain resonant capacitors or resonant inductors, and each component can be composed of different series and parallel modes; and the secondary side rectifier circuit is composed of full bridge rectification, It is composed of half-bridge rectification or center-tap rectification circuit. A power converter includes: an AC to DC converter, including an AC power input terminal, a DC power output terminal, and an AC to DC control terminal, a DC to DC converter; it includes a switching circuit, the switching circuit The switch in is selectively turned on or off according to the gate generator to convert the DC voltage into an AC signal; a primary resonant tank electrically connected to the switching circuit on the side for receiving the AC signal to provide A resonant current; a current detection circuit for detecting the resonant current and outputting a current signal according to the resonant current; a transformer, including: a primary winding, which is connected to the primary resonance tank and receives the primary AC signal; The primary and secondary windings will induce the AC signal from the primary side to the secondary side and provide it to the secondary side resonant tank; a secondary side resonant tank, electrically connected to the transformer to provide current to a rectifier circuit; a rectifier circuit, electric It is connected to the secondary-side resonant tank to rectify the AC signal output by the secondary-side resonant tank and provide an output voltage; the DC-DC converter controller calculates the required switching circuit according to the output voltage. Switch frequency. The power converter as claimed in item 12 further includes a gate signal generator which is connected to a switch such as a DC-DC converter controller, a switching circuit, and a rectifier circuit. The DC-DC converter The controller calculates according to the change of the output voltage, and outputs the corresponding switching frequency to the gate signal generator to control the opening and closing of the switch. The power converter as claimed in item 12 has a function of resonant frequency tracking, wherein a current detector is used to detect the resonant current to a zero-crossing point detection and a peak detection, and the zero-crossing point detection and Peak detection can provide voltage signals to an online resonance frequency calculation unit, and the online resonance frequency calculation unit will provide a quarter of the actual first resonance period, and then use an adjustable voltage control unit to adjust the AC to DC converter The output voltage of the DC-DC converter makes the switching frequency operation approach or equal to the first resonant frequency of the resonant converter. If the power converter described in item 14 is requested, the resonant frequency calculation on the line will capture the zero-crossing point detection voltage signal rising edge time and the peak detection voltage signal rising edge time. After calculating the two time points, define This period of time is a quarter of the actual first resonance period, and the first resonance frequency of the resonant converter can be obtained. If the power converter described in item 14 is requested, after the online resonance frequency calculation unit provides a quarter of the actual first resonance period, the actual first resonance is obtained Cycle and the actual switching cycle provided by the DC-DC converter controller. The adjustable voltage controller unit calculates the difference and the output voltage value of the AC-DC converter to be adjusted. The output of the controller is sent to the AC-DC converter. The control end of the converter adjusts the output voltage of the AC-to-DC converter and controls the switching frequency of the DC-to-DC converter to approach or equal to the first resonant frequency of the resonant converter. According to the power converter described in item 16, the actual switching period obtained by the adjustable voltage controller unit is greater than the actual first resonance period, and the adjustable voltage controller unit will increase the Output voltage reference value to increase the switching frequency of the DC-DC converter. According to the power converter described in item 16, the actual switching period obtained by the adjustable voltage controller unit is less than the actual first resonance period, and the adjustable voltage controller unit will reduce the original AC to DC converter's Output voltage reference value to reduce the switching frequency of the DC-DC converter. The power converter as claimed in item 12 has a quick response function, and the above-mentioned resonance frequency tracking function is modularized, and the other module is a frequency modulation module, which is to detect the output voltage to adjust The function of switching frequency uses these two modules as the mode control, and this control is the mode control module. For the power converter described in item 12 of the request, the mode control decision is mainly calculated by the output voltage of the resonant converter and the reference value of the output voltage, and the output error value after the calculation is used to judge; in the steady state, the error value Less than a threshold Value, it will work on the resonant frequency tracking module; when the error value is greater than another threshold, the module will switch to the frequency modulation module to improve the response speed. The power converter described in items 12 to 20 is requested and has a fast response function. The DC-DC converter has a resonant tank converter, which has a switching circuit, a primary resonant tank, and a current detection The circuit, a transformer, a secondary resonance tank, a rectifier circuit, a DC-DC converter controller and a gate signal generator. The switching signal of the power switch in the switching circuit is generated and controlled by the gate signal generator, and the switching circuit is connected to the primary resonance tank, and the primary resonance tank is connected to the transformer, and the transformer is connected to the secondary resonance tank. The side resonance tank is connected to the rectifier circuit of the DC-DC converter. The power converter as described in items 12 to 20 is requested and has a fast response function. The DC-to-DC converter has a resonant tank converter and has a switching circuit. The switching circuit is composed of a full-bridge switching circuit and a half-bridge. It consists of a switching circuit or a third-order switching circuit; it has a primary-side resonant tank, and this primary-side resonant tank contains a resonant capacitor, a resonant inductor or a magnetizing inductance, and each element can be composed of different series and parallel ways; it has a secondary-side resonant tank The secondary-side resonant tank may contain a resonant capacitor or a resonant inductor, and each element may be composed of different series-parallel connections; the secondary-side rectifier circuit is composed of a full-bridge rectifier, a half-bridge rectifier, or a center-tapped rectifier circuit. A control method of a power converter includes: through a power converter A gate signal generator outputs a gate signal to control the corresponding switch in the primary side switching circuit in the power converter to switch an AC signal received by a resonant circuit in the power converter; through the power converter A current detection circuit in the system detects a resonant current flowing through the resonant circuit in the power converter, and extracts the time of the zero-crossing point and peak detection point of the resonant current to provide to an online resonant frequency calculation unit Through the online resonant frequency calculation unit, a quarter of the actual first resonant period can be obtained, and then an adjustable voltage controller unit is used to adjust the output voltage of the AC-to-DC converter to operate the switching frequency of the DC-to-DC converter. Approaching or equal to the first resonant frequency of the resonant converter. The control method of the power converter according to claim 23, wherein adjusting the switching frequency of the gate signal generator includes: when the actual switching period obtained by the adjustable voltage controller unit is greater than the actual first resonance period, the The adjustable voltage controller unit will increase the reference value of the original AC-to-DC converter output voltage to increase the switching frequency of the DC-to-DC converter; and the actual switching period obtained by the adjustable voltage controller unit is less than the actual first resonance During the period, the adjustable voltage controller unit will reduce the reference value of the output voltage of the original AC-to-DC converter to reduce the switching frequency of the DC-to-DC converter.

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