TWI778542B - Resonance control device and resonance control method thereof - Google Patents

Abstract

The invention discloses a resonance control device and a resonance control method thereof. The resonance control device includes a feedback controller and a processor. The feedback controller receives a reference voltage and an output voltage, and uses the reference voltage to perform voltage compensation on the output voltage to generate a control parameter. The processor receives the control parameter, and generates a pulse modulation signal according to the control parameter and the switching parameter, so as to drive the resonant converter to adjust the output voltage. Each pulse modulation signal has a maximum frequency and a minimum frequency, and the maximum frequency corresponds to the switching parameter. When the control parameter is greater than or equal to the switching parameter, the frequency of the pulse modulation signal is adjusted according to the control parameter and the switching parameter, or the resonant converter is controlled to operate at a fixed time in each cycle of the pulse modulation signal, so as to avoid the resonant converter switching loss.

Description

Resonance control device and resonance control method thereof

The present invention relates to a resonance control technology, and in particular, to a resonance control device and a resonance control method thereof.

In recent years, all kinds of electronic products are developing in the direction of precision and miniaturization. Traditional power converters cannot meet today's needs in terms of volume and efficiency. Power converters are required to increase power density (Power Density). In the 1990s, when power semiconductor technology matured, switching power supplies were widely used in power supplies. Therefore, high-efficiency Switch Mode Power Supply (SMPS) is now the focus of the industry in power supply design.

Switching power supplies use either half-bridge resonant converters or full-bridge resonant converters. Please refer to FIG. 1 and FIG. 2. Since the operation of the half-bridge resonant converter is similar to that of the full-bridge resonant converter, the half-bridge resonant converter 1 is taken as an example, which is generally set as shown in FIG. 1. As shown, it includes a signal controller 10, a first electronic switch 11, a second electronic switch 12, a resonant tank 13 and a transformer 14, wherein the first electronic switch 11 and the second electronic switch 12 are both N-channel metal oxide Half Field Effect Transistor. Theoretically, the signal controller 10 generates a two-pulse modulation signal to control the first electronic switch 11 and the second electronic switch 12 to switch alternately, that is, when the first electronic switch 11 is turned on, the second electronic switch 12 is turned off, The energy is stored in the resonance tank 13 from the high voltage terminal VH. When the first electronic switch 11 is turned off, the second electronic switch 12 is turned on, so that the energy is released from the resonance tank 13 to the low voltage terminal VL. The transformer 18 receives the energy of the resonant tank 13 to convert it into an output voltage Vo, and applies the output voltage Vo to the load 15 to generate an output current Io. The output voltage Vo and the output current Io form an output power W. The signal controller 10 executes a pulse width modulation (PWM) mode or a pulse frequency modulation (PFM) mode according to the output power W. In the PWM mode, the PWM signal is a PWM signal. In the pulse frequency modulation mode, the pulse frequency modulation signal is a pulse frequency modulation signal. In the PWM mode, the duty cycle D of the PWM signal starts to increase from a threshold value d until the duty cycle D is 0.5. In the pulse frequency modulation mode, the duty cycle D of the pulse frequency modulation signal is 0.5. In the PWM mode, the frequency F of the PWM signal increases as the output power W decreases, and the frequency F of the PWM signal increases from the minimum frequency f1 until the frequency F is equal to the maximum frequency f2 . In the PWM mode, the frequency F of the PWM signal is equal to the maximum frequency f2. If the half-bridge resonant converter 1 is to operate in the lower limit range of the output voltage Vo, the frequency F of the PWM signal must be increased to maintain the output voltage Vo. The pulse width modulation mode and the pulse frequency modulation mode can improve the light-load efficiency and reduce the resonant current when the resonant converter 1 starts up. However, due to the hardware characteristics of the signal controller 10, the frequency F of the PWM signal cannot be increased indefinitely, so the PWM mode is used to achieve the same effect as increasing the frequency F, but the lower limit range of the output voltage Vo is Still not low enough to make the half-bridge resonant converter 1 unsuitable for applications where the output voltage Vo operates in a wide range. Furthermore, the PWM mode is in a high frequency state, so the switching loss is large and the noise is high.

Therefore, the present invention provides a resonance control device and a resonance control method thereof to solve the problems caused by the prior art in view of the above-mentioned problems.

The present invention provides a resonance control device and a resonance control method thereof, which improve the light-load efficiency of a resonant converter, reduce the start-up resonant current, reduce switching loss and noise, and increase the lower limit of the output voltage of the resonant converter range and expand the operating range of this output voltage.

In one embodiment of the present invention, a resonance control device includes a feedback controller and a processor. The feedback controller is coupled to an output terminal of a resonant converter, the output terminal is coupled to a load, and an output voltage is applied to the load, wherein the feedback controller is used for receiving a reference voltage and the output voltage, and using the reference voltage to perform voltage on the output voltage compensation to generate a control parameter. The processor is coupled to the feedback controller and the resonant converter, and presets a switching parameter, the processor is used for receiving the control parameter, and generates a pulse modulation signal according to the switching parameter, and drives the resonant conversion by the pulse modulation signal The output voltage is adjusted by the controller. The pulse modulation signal has a maximum frequency and a minimum frequency, and the maximum frequency corresponds to the switching parameter. When the control parameter is greater than or equal to the switching parameter, the pulse wave modulation signal is a pulse frequency modulation signal. When the control parameter is less than the switching parameter, the pulse modulation signal controls the resonant converter to operate for a fixed time in each cycle of the pulse modulation signal.

In an embodiment of the present invention, the duty cycle of the pulse frequency modulation signal is 0.5.

In an embodiment of the present invention, the output voltage is applied to the load to generate an output current, the output current and the output voltage form an output power, and the frequency of the PWM signal is linearly inversely proportional to the output power.

In one embodiment of the present invention, the output voltage is applied to the load to generate an output current, and the output current and the output voltage form an output power. When the control parameter is smaller than the switching parameter, the frequency of the PWM signal is linearly proportional to the output power.

In one embodiment of the present invention, when the control parameter is less than the switching parameter, the duty cycle of the pulse modulation signal is linearly proportional to the output power, the maximum duty cycle is 0.5, and the minimum duty cycle is equal to the fixed time multiplied by Minimum frequency, the minimum value is less than 0.5.

In an embodiment of the present invention, the switching parameter is equal to the maximum frequency, and the feedback controller includes a subtractor, a voltage compensator and a digital voltage controlled oscillator. The subtractor is coupled to the output terminal, wherein the subtractor is used for receiving the reference voltage and the output voltage, and subtracting the output voltage from the reference voltage to obtain a difference voltage. The voltage compensator is coupled to the subtractor, wherein the voltage compensator is used for receiving the difference voltage and performing voltage compensation on it to generate a voltage parameter. The digital voltage controlled oscillator is coupled to the voltage compensator and the processor, wherein the digital voltage controlled oscillator is used for receiving the voltage parameter, and generating a control frequency as one of the control parameters according to the voltage parameter, the maximum frequency and the minimum frequency.

In an embodiment of the present invention, the control frequency is represented by Fc, Fc=( _Fmin - _Fmax )×P+ _Fmax , _Fmin is the minimum frequency, _Fmax is the maximum frequency, and P is a voltage parameter.

In an embodiment of the present invention, the voltage compensator is a proportional-integral-derivative controller (PID controller) or a proportional-integral controller (PI controller).

In an embodiment of the present invention, the resonant converter is a full-bridge resonate converter or a half-bridge resonate converter.

、一激磁電感(Magnetizing Inductor）

與一諧振電容(Resonating Capacitor)

串聯而成，最小頻率大於

，且小於

，最大頻率大於

。 In an embodiment of the present invention, the minimum frequency and the maximum frequency are determined by a resonant tank of the resonant converter, and the resonant tank is composed of a resonating inductor (Resonating Inductor)

, a magnetizing inductor (Magnetizing Inductor)

with a Resonating Capacitor

connected in series, the minimum frequency is greater than

, and less than

, the maximum frequency is greater than

.

In one embodiment of the present invention, a resonant control method controls a resonant converter, the resonant converter is coupled to a load, and the load has an output voltage, and the resonant control method includes the following steps: receiving a reference voltage and an output voltage, and utilizing The reference voltage performs voltage compensation on the output voltage to generate a control parameter; and receives the control parameter, and determines whether the control parameter is less than a switching parameter: if yes, generates a pulse modulation signal according to the control parameter and the switching parameter, so as to control the resonance The converter operates at a fixed time in each cycle of the pulse modulation signal to adjust the output voltage; and if not, generates a pulse frequency modulation signal according to the control parameter and the switching parameter, so as to drive the resonant converter to adjust the output Voltage; wherein the pulse frequency modulation signal and the pulse wave modulation signal have a maximum frequency and a minimum frequency, and the maximum frequency corresponds to the switching parameter.

In an embodiment of the present invention, the duty cycle of the pulse frequency modulation signal is 0.5.

In an embodiment of the present invention, the output voltage is applied to a load to generate an output current, the output current and the output voltage form an output power, and the frequency of the PWM signal is linearly inversely proportional to the output power.

In one embodiment of the present invention, the output voltage is applied to the load to generate an output current, and the output current and the output voltage form an output power. When the control parameter is smaller than the switching parameter, the frequency of the PWM signal is linearly proportional to the output power.

In one embodiment of the present invention, when the control parameter is less than the switching parameter, the duty cycle of the pulse modulation signal is linearly proportional to the output power, the maximum duty cycle is 0.5, and the minimum duty cycle is equal to the fixed time multiplied by Minimum frequency, the minimum value is less than 0.5.

In one embodiment of the present invention, the switching parameter is equal to the maximum frequency, and the step of receiving the reference voltage and the output voltage, and using the reference voltage to perform voltage compensation on the output voltage to generate the control parameter includes the following steps: receiving the reference voltage and output voltage, subtract the output voltage from the reference voltage to obtain a differential voltage; receive the differential voltage and perform voltage compensation on it to generate a voltage parameter; and receive the voltage parameter and generate according to the voltage parameter, the maximum frequency and the minimum frequency Control the frequency as one of the control parameters.

In an embodiment of the present invention, the control frequency is represented by Fc, Fc=( _Fmin - _Fmax )×P+ _Fmax , _Fmin is the minimum frequency, _Fmax is the maximum frequency, and P is a voltage parameter.

、一激磁電感(Magnetizing Inductor）

與一諧振電容(Resonating Capacitor)

串聯而成，最小頻率大於

，且小於

，最大頻率大於

。 In an embodiment of the present invention, the minimum frequency and the maximum frequency are determined by the resonant tank of the resonant converter, and the resonant tank is determined by a resonating inductor (Resonating Inductor)

, a magnetizing inductor (Magnetizing Inductor)

with a Resonating Capacitor

connected in series, the minimum frequency is greater than

, and less than

, the maximum frequency is greater than

.

Based on the above, the resonance control device and the resonance control method thereof can set a switching parameter and perform a constant on-time (COT) modulation mode or a pulse frequency modulation mode according to the switching parameter without increasing the hardware cost. Change the mode to improve the light-load efficiency of the resonant converter, reduce the start-up resonant current, reduce the switching loss and noise, increase the lower limit range of the output voltage of the resonant converter, and expand the operating range of the output voltage. In addition, the digital voltage-controlled oscillator generates the control frequency, which is linearly inversely proportional to the voltage parameter, so as to improve the stability of the variation of the control parameter.

Hereby, in order to make your examiners have a further understanding and understanding of the structural features of the present invention and the effects achieved, I would like to assist with the preferred embodiment drawings and coordinate detailed descriptions, and the descriptions are as follows:

Embodiments of the present invention will be further explained with the help of the related drawings below. Wherever possible, in the drawings and the description, the same reference numbers refer to the same or similar components. In the drawings, shapes and thicknesses may be exaggerated for simplicity and convenience. It should be understood that the elements not particularly shown in the drawings or described in the specification have forms known to those of ordinary skill in the art. Those skilled in the art can make various changes and modifications based on the content of the present invention.

When an element is referred to as being "on", it can generally mean that the element is directly on the other element or that the other element is present in both. Conversely, when an element is said to be "directly on" another element, it cannot have the other element intervening. As used herein, the term "and/or" includes any combination of one or more of the associated listed items.

The following description of "one embodiment" or "an embodiment" refers to a particular element, structure or feature associated with at least one embodiment. Thus, the appearances of "one embodiment" or "an embodiment" in various places below are not directed to the same embodiment. Furthermore, the specific components, structures and features in one or more embodiments may be combined in a suitable manner.

The disclosure is specifically described with the following examples, which are only for illustration, because for those skilled in the art, various changes and modifications can be made without departing from the spirit and scope of the present disclosure. The scope of protection of the disclosed contents shall be determined by the scope of the appended patent application. Throughout the specification and claims, unless the content clearly dictates otherwise, the meanings of "a" and "the" include that such recitations include "one or at least one" of the element or ingredient. Furthermore, as used in this disclosure, a singular article also includes the recitation of a plurality of elements or components unless the exclusion of the plural is obvious from the specific context. Also, as used in this description and throughout the claims below, the meaning of "in" may include "in" and "on" unless the content clearly dictates otherwise. Terms used throughout the specification and the scope of the patent application, unless otherwise specified, generally have the ordinary meaning of each term used in the field, in the content disclosed herein and in the specific content. Certain terms used to describe the present disclosure are discussed below or elsewhere in this specification to provide practitioners with additional guidance in describing the present disclosure. Examples anywhere throughout the specification, including the use of examples of any terms discussed herein, are by way of illustration only, and of course do not limit the scope and meaning of the disclosure or any exemplified terms. Likewise, the present disclosure is not limited to the various embodiments set forth in this specification.

Furthermore, if the term "electrically (physically) coupled" or "electrically (physically) coupled" is used herein, it includes any means of direct and indirect electrical coupling. For example, if it is described in the text that a first device is electrically coupled to a second device, it means that the first device can be directly coupled to the second device, or indirectly coupled to the second device through other devices or coupling means the second device. In addition, if the transmission and provision of electrical signals are described, those skilled in the art should understand that the transmission of electrical signals may be accompanied by attenuation or other non-ideal changes. In fact, it should be regarded as the same signal. For example, if the electrical signal S is transmitted (or provided) from the terminal A of the electronic circuit to the terminal B of the electronic circuit, it may pass through the source and drain terminals of a transistor switch and/or possible stray capacitance. A voltage drop is generated, but the purpose of this design is not to deliberately use the attenuation or other non-ideal changes generated during transmission (or supply) to achieve some specific technical effects. The electrical signal S is at the terminal A and the terminal of the electronic circuit. B should be regarded as substantially the same signal.

It is to be understood that the terms "comprising", "including", "having", "containing", "involving" and the like as used herein are open-ended open-ended, which means including but not limited to. In addition, any embodiment of the present invention or the scope of the claims is not required to achieve all of the objects or advantages or features disclosed herein. In addition, the abstract part and the title are only used to assist the search of patent documents, not to limit the scope of the invention.

FIG. 3 is a schematic circuit diagram of the resonance control device and the resonance converter according to the first embodiment of the present invention. FIG. 4 is a graph showing the duty cycle and frequency of the pulse modulation signal relative to the output power according to an embodiment of the present invention. FIG. 5 is a waveform diagram of a pulse modulation signal in a pulse frequency modulation mode according to an embodiment of the present invention. FIG. 6 is a waveform diagram of a pulse modulation signal in a constant on-time mode according to an embodiment of the present invention. Please refer to FIG. 3 and FIG. 4 , the following describes the resonance control device 2 according to the first embodiment of the present invention. The resonance control device 2 includes a feedback controller 20 and a processor 21 . The feedback controller 20 is coupled to an output terminal of a resonant converter 3, the output terminal is coupled to a load 4, and an output voltage V is applied to the load 4. The output voltage V is applied to the load 4 to generate an output current I, and the output current I is equal to The output voltage V forms an output power W. The resonant converter 3 may be a full-bridge resonate converter or a half-bridge resonate converter. The feedback controller 20 is used for receiving a reference voltage S and the output voltage V, and using the reference voltage S to perform voltage compensation on the output voltage V to generate a control parameter C. The processor 21 is coupled to the feedback controller 20 and the resonant converter 3, and presets a switching parameter. The processor 21 is used for receiving the control parameter C, to generate pulse modulation signals P and P' according to the switching parameter and to drive the resonant converter 3 to adjust the output voltage V by the pulse modulation signals P and P'. The pulse modulation signals P and P' have a maximum frequency represented by F _max and a minimum frequency represented by F _min , and the maximum frequency F _max corresponds to a switching parameter. When the control parameter C is greater than or equal to the switching parameter, the pulse modulation signals P and P' are pulse frequency modulation signals, so that the resonant converter 3 performs a pulse frequency modulation (PFM) mode. When the control parameter C is smaller than the switching parameter, the pulse modulation signals P and P' control the resonant converter 3 to operate for a fixed time during each cycle of the pulse modulation signals P and P', so that the resonant converter 3 performs constant On-time (COT) mode.

、一激磁電感(Magnetizing Inductor）

與一諧振電容(Resonating Capacitor)

串聯而成，最小頻率F _min大於

，且小於

，最大頻率F _max大於

。 In some embodiments of the present invention, the resonant converter 3 may include an electronic switch group 30 , a resonant tank 31 and a transformer 32 . The electronic switch group 30 is coupled to the processor 21 and the resonant tank 31 . The resonant tank 31 is coupled to the primary side of the transformer 32 , and the secondary side of the transformer 32 serves as the output end of the resonant converter 3 . The electronic switch group 30 is used for receiving the pulse modulation signals P and P', so as to drive the transformer 32 through the resonant tank 31, thereby changing the output voltage V. As shown in FIG. For example, the minimum frequency F _min and the maximum frequency F _max are determined by the resonant tank 31 of the resonant converter 3 , and the resonant tank 31 is determined by a resonating inductor (Resonating Inductor)

, a magnetizing inductor (Magnetizing Inductor)

with a Resonating Capacitor

connected in series, the minimum frequency F _min is greater than

, and less than

, the maximum frequency F _max is greater than

.

As shown in Figure 3, Figure 4, Figure 5 and Figure 6, the duty cycle of the PWM signal can be fixed at 0.5, and the frequency F of the PWM signal is linearly inversely proportional to the output power W. The maximum value of the frequency F is the maximum frequency F _max , and the minimum value of the frequency F is the minimum frequency F _min . The two PWM signals do not have a high level voltage at the same time to avoid burning the circuit. If the frequency F of the pulse frequency modulation signal is less than the minimum frequency F _min , the pulse frequency modulation signal has the minimum value M of the duty cycle D. When the control parameter C is less than the switching parameter, the frequencies F of the pulse modulation signals P and P' can be linearly proportional to the output power W, and the maximum and minimum values of the frequencies F of the pulse modulation signals P and P' are respectively Maximum frequency F _max and minimum frequency F _min . When the control parameter C is less than the switching parameter, the duty cycle D of the pulse modulation signals P and P' is linearly proportional to the output power W, and the maximum value of the duty cycle D is 0.5, and the minimum value M of the duty cycle D is equal to the resonant converter 3. The operating fixed time T is multiplied by the minimum frequency _Fmin , and the minimum value M of the duty cycle D is less than 0.5. Generally speaking, the fixed time T is the shortest period in which the resonant converter 3 operates, and is determined by the hardware of the resonant converter 3 . In the COT mode, the operating time of the resonant converter 3 is fixed and the frequency F is changed to obtain a variable duty period D. As shown in Figure 6, the phase of the pulse modulation signal P' lags behind the phase of the pulse modulation signal P by 180 degrees, and the pulse modulation signals P and P' do not have high-level voltages at the same time to avoid burnout circuit. On the premise of not increasing the hardware cost, the resonance control device sets the switching parameters, and performs constant on-time modulation mode or pulse frequency modulation mode according to the switching parameters, so as to improve the light-load efficiency of the resonant converter 3 and reduce the start-up resonance current and reduce switching losses and noise. In addition, the constant on-time modulation mode can extend the range of output voltage or output current that the PWM mode cannot cover. Therefore, the resonance control device 2 can increase the lower limit range of the output voltage of the resonant converter 3 and expand the operation range of the output voltage, and reduce the number of times of executing the burst mode.

FIG. 7 is a flowchart of a resonance control method according to an embodiment of the present invention. Please refer to FIG. 3 and FIG. 7 , the following describes the resonance control method of the resonance control device 2 according to an embodiment of the present invention. First, as shown in step S10, the feedback controller 20 receives the reference voltage S and the output voltage V, and uses the reference voltage S to perform voltage compensation on the output voltage V to generate the control parameter C. As shown in step S12, the processor 21 receives the control parameter C, and determines whether the control parameter C is smaller than the switching parameter. If so, as shown in step S14, the processor 21 generates the pulse modulation signals P and P' according to the control parameter C and the switching parameter, so as to control the resonant converter 3 at each pulse modulation signal P or P'. It operates at a fixed time in one cycle to adjust the output voltage V. If not, as shown in step S16, the processor 21 generates a pulse frequency modulation signal according to the control parameter C and the switching parameter, so as to drive the resonant converter 3 to adjust the output voltage V thereby.

See Figures 3 and 4. When the load 4 becomes lighter, the control parameter C becomes smaller. When the control parameter C is smaller than the switching parameter, the processor 21 generates the pulse modulation signals P and P', thereby controlling the resonant converter 3 to operate for a fixed time in each cycle of the pulse modulation signal P or P' , and then adjust the output voltage V. The duty cycle D and frequency F of the pulse modulation signals P and P' depend on the output power W. When the load 4 becomes heavier, the control parameter C becomes larger. When the control parameter C is greater than or equal to the switching parameter, the processor 21 generates a pulse frequency modulation signal according to the control parameter C and the switching parameter, so as to drive the resonant converter 3 to adjust the output voltage V thereby. The frequency F of the PWM signal depends on the output power W, and the duty cycle D of the PWM signal is fixed at 0.5. In addition, the reference voltage S can also be varied to generate the pulse modulation signals P and P' or the pulse frequency modulation signal. When the reference voltage S decreases and the output voltage V has not changed, the control parameter C becomes smaller. When the control parameter C is smaller than the switching parameter, the processor 21 generates the pulse modulation signals P and P', thereby controlling the resonant converter 3 to operate for a fixed time in each cycle of the pulse modulation signal P or P' , and then adjust the output voltage V. The duty cycle D and frequency F of the pulse modulation signals P and P' depend on the output power W. When the reference voltage S increases and the output voltage V has not changed, the control parameter C becomes larger. When the control parameter C is greater than or equal to the switching parameter, the processor 21 generates a pulse frequency modulation signal according to the control parameter C and the switching parameter, so as to drive the resonant converter 3 to adjust the output voltage V thereby. The frequency F of the PWM signal depends on the output power W, and the duty cycle D of the PWM signal is fixed at 0.5.

FIG. 8 is a schematic circuit diagram of the resonance control device and the resonance converter according to the second embodiment of the present invention. FIG. 9 is a flow chart of generating control parameters according to an embodiment of the present invention. Please refer to FIG. 8 and FIG. 9 , the following describes the resonance control device 2 according to the second embodiment of the present invention. The difference between the second embodiment and the first embodiment lies in the feedback controller 20 , the switching parameter and the control parameter C, and other technical features are the same as those in the first embodiment, which will not be repeated here. In the second embodiment, the switching parameter is equal to the maximum frequency F _max , and the feedback controller 20 includes a subtractor 200 , a voltage compensator 201 and a digital voltage controlled oscillator 202 . The voltage compensator 201 is coupled to the subtractor 200 and the digital voltage controlled oscillator 202 , and the digital voltage controlled oscillator 202 is coupled to the processor 21 . The following describes the process of generating control parameters according to an embodiment of the present invention. First, as shown in step S100, the subtractor 200 receives the reference voltage S and the output voltage V, and subtracts the output voltage V from the reference voltage S to obtain a difference voltage VD. Next, as shown in step S101, the voltage compensator 201 receives the difference voltage VD and performs voltage compensation on it to generate a voltage parameter VP. The voltage parameter VP is a coefficient related to voltage, but has no unit. Finally, as shown in step S102, the digital voltage controlled oscillator 202 receives the voltage parameter VP, and generates a control frequency as one of the control parameters C according to the voltage parameter VP, the maximum frequency F _max and the minimum frequency F _min . In some embodiments of the present invention, the control frequency is represented by Fc, Fc=( _Fmin - _Fmax )×P+ _Fmax , and P is a voltage parameter. Since the control frequency and the voltage parameter have a linear inverse proportional relationship, the stability of the variation of the control parameter C can be improved.

According to the above-mentioned embodiments, the resonance control device and the resonance control method thereof can set a switching parameter and perform a constant on-time modulation mode or a pulse frequency modulation mode according to the switching parameter to improve the resonance without increasing the hardware cost. The light load efficiency of the converter is reduced, the start-up resonant current is reduced, the switching loss and noise are reduced, the lower limit range of the output voltage of the resonant converter is improved, and the operating range of the output voltage is enlarged. In addition, the digital voltage-controlled oscillator generates the control frequency, which is linearly inversely proportional to the voltage parameter, so as to improve the stability of the variation of the control parameter.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, all changes and modifications made in accordance with the shape, structure, feature and spirit described in the scope of the patent application of the present invention are equivalent. , shall be included in the scope of the patent application of the present invention.

…諧振電感

…激磁電感

…諧振電容 S10、S12、S14、S16、S100、S101、S102…步驟 1...resonant converter 10...signal controller 11...first electronic switch 12...second electronic switch 13...resonant tank 14...transformer 15...load 2...resonance control device 20...feedback controller 200...subtractor 201...voltage Compensator 202...Digital Voltage Controlled Oscillator 21...Processor 3...Resonant Converter 30...Electronic Switch Group 31...Resonant Tank 32...Transformer 4...Load VH...High Voltage Terminal VL...Low Voltage Terminal Vo...Output Voltage Io...Output Current D...responsibility period d...critical value F...frequency W...output power f1...minimum frequency f2...maximum frequency V...output voltage I...output current S...reference voltage C...control parameters P and P'...pulse modulation signal F _max ...maximum frequency F _min... minimum frequency M...minimum T...fixed time

…resonant inductance

…magnetizing inductance

...resonant capacitors S10, S12, S14, S16, S100, S101, S102...steps

FIG. 1 is a schematic circuit diagram of a resonant converter of the prior art. FIG. 2 is a graph of the duty cycle and frequency of the prior art pulse modulation signal versus output power. FIG. 3 is a schematic circuit diagram of the resonance control device and the resonance converter according to the first embodiment of the present invention. FIG. 4 is a graph showing the duty cycle and frequency of the pulse modulation signal relative to the output power according to an embodiment of the present invention. FIG. 5 is a waveform diagram of a pulse modulation signal in a pulse frequency modulation mode according to an embodiment of the present invention. FIG. 6 is a waveform diagram of a pulse modulation signal in a constant on-time mode according to an embodiment of the present invention. FIG. 7 is a flowchart of a resonance control method according to an embodiment of the present invention. FIG. 8 is a schematic circuit diagram of the resonance control device and the resonance converter according to the second embodiment of the present invention. FIG. 9 is a flow chart of generating control parameters according to an embodiment of the present invention.

D... duty cycle W... output power F _max ... maximum frequency F _min... minimum frequency M... minimum value F... frequency

Claims (16)

A resonance control device, comprising: a feedback controller, coupled to an output end of a resonance converter, the output end is coupled to a load, the load has an output voltage, wherein the feedback controller is used for receiving a reference voltage and The output voltage is voltage compensated by the reference voltage to generate a control parameter; and a processor is coupled to the feedback controller and the resonant converter, and presets a switching parameter, the processing The controller is used for receiving the control parameter to generate a pulse modulation signal according to the switching parameter, and to drive the resonant converter to adjust the output voltage by the pulse modulation signal. The pulse modulation signal has a maximum frequency and a minimum frequency Frequency, the maximum frequency corresponds to the switching parameter, when the control parameter is greater than or equal to the switching parameter, the pulse modulation signal is a pulse frequency modulation signal, when the control parameter is less than the switching parameter, the pulse modulation The variable signal controls the resonant converter to operate at a fixed time in each cycle of the pulse modulation signal; wherein the output voltage is applied to the load to generate an output current, and the output current and the output voltage form an output power, which is When the control parameter is smaller than the switching parameter, the frequency of the pulse modulation signal is linearly proportional to the output power. The resonance control device as claimed in claim 1, wherein the duty cycle of the pulse frequency modulation signal is 0.5. The resonance control device of claim 2, wherein the frequency of the pulse frequency modulation signal is linearly inversely proportional to the output power. The resonance control device according to claim 1, wherein when the control parameter is less than the switching parameter, the duty cycle of the pulse modulation signal is linearly proportional to the output power, and the maximum value of the duty cycle is 0.5, and the duty cycle The minimum value is equal to the fixed time multiplied by The minimum frequency, the minimum value is less than 0.5. The resonance control device of claim 1, wherein the switching parameter is equal to the maximum frequency, and the feedback controller comprises: a subtractor coupled to the output, wherein the subtractor is used for receiving the reference voltage and the output voltage, the reference voltage is subtracted from the output voltage to obtain a difference voltage; a voltage compensator is coupled to the subtractor, wherein the voltage compensator is used for receiving the difference voltage and performing voltage compensation on it to generate a voltage compensator voltage parameters; and a digital voltage-controlled oscillator coupled to the voltage compensator and the processor, wherein the digital voltage-controlled oscillator is used for receiving the voltage parameters, and according to the voltage parameters, the maximum frequency and the minimum Frequency generation controls the frequency as one of the control parameters. The resonance control device according to claim 5, wherein the control frequency is represented by Fc, Fc=( _Fmin - _Fmax )×P+ _Fmax , _Fmin is the minimum frequency, _Fmax is the maximum frequency, and P is the the voltage parameter. The resonance control device of claim 5, wherein the voltage compensator is a PID controller or a PI controller. The resonance control device of claim 1, wherein the resonant converter is a full-bridge resonate converter or a half-bridge resonate converter. The resonance control device of claim 1, _wherein the minimum frequency and the maximum frequency are determined by a resonant tank of the resonant converter, and the resonant tank is composed of a resonating inductor LR , a magnetizing inductor ) L _M is formed in series with a resonating capacitor (Resonating Capacitor) C _R , the minimum frequency is greater than

, and less than

, the maximum frequency is greater than

A resonance control method, which controls a resonance converter, the resonance converter is coupled to a load, the load has an output voltage, the resonance control method comprises the following steps: receiving a reference voltage and the output voltage, and using the reference voltage The output voltage is voltage compensated to generate a control parameter; and the control parameter is received, and it is judged whether the control parameter is less than a switching parameter; if so, a pulse wave modulation signal is generated according to the control parameter and the switching parameter to Thereby, the resonant converter is controlled to operate at a fixed time in each cycle of the pulse modulation signal, so as to adjust the output voltage; and if not, a pulse frequency modulation signal is generated according to the control parameter and the switching parameter, thereby driving the resonant converter to adjust the output voltage; wherein the pulse frequency modulation signal and the pulse modulation signal have a maximum frequency and a minimum frequency, and the maximum frequency corresponds to the switching parameter; wherein the output voltage applies the load In order to generate an output current, the output current and the output voltage form an output power. When the control parameter is less than the switching parameter, the frequency of the pulse modulation signal is linearly proportional to the output power. The resonance control method as claimed in claim 10, wherein the duty cycle of the pulse frequency modulation signal is 0.5. The resonance control method of claim 10, wherein the frequency of the pulse frequency modulation signal is linearly inversely proportional to the output power. The resonance control method of claim 10, wherein the control parameter is less than the cutoff When changing parameters, the duty cycle of the pulse modulation signal is linearly proportional to the output power, and the maximum duty cycle is 0.5, the minimum duty cycle is equal to the fixed time multiplied by the minimum frequency, and the minimum value is less than 0.5. The resonance control method of claim 10, wherein the switching parameter is equal to the maximum frequency, and the reference voltage and the output voltage are received, and the reference voltage is used to perform voltage compensation on the output voltage to generate the control parameter , comprising the following steps: receiving the reference voltage and the output voltage, subtracting the output voltage from the reference voltage to obtain a difference voltage; receiving the difference voltage and performing voltage compensation on it to generate a voltage parameter; and receiving The voltage parameter is generated according to the voltage parameter, the maximum frequency and the minimum frequency as one of the control parameters. The resonance control method according to claim 14, wherein the control frequency is represented by Fc, Fc=( _Fmin - _Fmax )×P+ _Fmax , _Fmin is the minimum frequency, _Fmax is the maximum frequency, and P is the the voltage parameter. The resonance control method of claim 10, _wherein the minimum frequency and the maximum frequency are determined by a resonant tank of the resonant converter, and the resonant tank is composed of a resonating inductor LR , a magnetizing inductor ) L _M is formed in series with a resonating capacitor (Resonating Capacitor) C _R , the minimum frequency is greater than

, and less than

, the maximum frequency is greater than

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