Resonance control device and resonance control method thereof

Abstract

The present invention discloses a resonant control device and a resonant control method. The resonant 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 based on the control parameter and a switching parameter 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 pulse modulation signal adjusts the frequency according to the control parameter and the switching parameter, or controls the resonant converter to operate at a fixed time in each cycle of the pulse modulation signal to avoid switching losses of the resonant converter.

Description

Technical Field

[0001] The present invention relates to a resonance control technology, and more particularly to a resonance control device and a resonance control method thereof. Background Art

[0002] In recent years, all kinds of electronic products have been 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. Therefore, when power semiconductor technology matured in the 1970s, switching power supplies were widely used in power supplies. Therefore, today's high-efficiency switching power supply (SMPS) is the focus of the industry in power supply design.

[0003] Switching power supplies use either a half-bridge resonant converter or a full-bridge resonant converter. Figure 1 and Figure 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. Figure 1As 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 semi-conductor field effect transistors. In theory, the signal controller 10 generates two pulse modulation signals 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, so that energy is stored in the resonant tank 13 from the high voltage end VH, and when the first electronic switch 11 is turned off, the second electronic switch 12 is turned on, so that energy is released from the resonant tank 13 to the low voltage end 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 performs a pulse width modulation (PWM) mode or a pulse frequency modulation (PFM) mode according to the output power W. In the pulse width modulation mode, the pulse modulation signal is a pulse width modulation signal. In the pulse frequency modulation mode, the pulse modulation signal is a pulse frequency modulation signal. In the pulse width modulation mode, the duty cycle D of the pulse width modulation signal increases from a critical 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 pulse frequency modulation mode, the frequency F of the pulse frequency modulation signal increases as the output power W decreases, and the frequency F of the pulse frequency modulation signal increases from the minimum frequency f1 until the frequency F is equal to the maximum frequency f2. In the pulse width modulation mode, the frequency F of the pulse width modulation signal is equal to the maximum frequency f2. If this half-bridge resonant converter 1 is to operate in the lower limit range of the output voltage Vo, the frequency F of the pulse width modulation 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 is started. However, due to the hardware characteristics of the signal controller 10, the frequency F of the pulse modulation signal cannot be increased indefinitely. Therefore, the pulse width modulation 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, making the half-bridge resonant converter 1 not suitable for use in occasions where the output voltage Vo operates in a wide range. Furthermore, the pulse width modulation mode is in a high frequency state, so the switching loss is larger and the noise is higher.

[0004] Therefore, in view of the above-mentioned difficulties, the present invention proposes a resonance control device and a resonance control method thereof to solve the problems generated by the prior art. Summary of the invention

[0005] The present invention provides a resonance control device and a resonance control method thereof, which can improve the light-load efficiency of a resonance converter, reduce the start-up resonance current, reduce switching loss and noise, increase the lower limit range of the output voltage of the resonance converter and expand the operating range of the output voltage.

[0006] In one embodiment of the present invention, a resonant control device includes a feedback controller and a processor. The feedback controller is coupled to the output end of a resonant converter, the output end is coupled to a load, and there is an output voltage on the load, wherein the feedback controller is used to receive a reference voltage and an output voltage, and use the reference voltage to perform voltage compensation on the output voltage 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 to receive the control parameter to generate a pulse modulation signal based on the control parameter and the switching parameter, and drive the resonant converter to adjust the output voltage through the pulse modulation signal. 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 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 at a fixed time in each cycle of the pulse modulation signal.

[0007] In one embodiment of the present invention, the duty cycle of the pulse frequency modulation signal is 0.5.

[0008] In one 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 pulse frequency modulation signal is linearly inversely proportional to the output power.

[0009] In one embodiment of the present invention, the output voltage applies a load to generate an output current, and 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.

[0010] 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, and the maximum value of the duty cycle is 0.5, and the minimum value of the duty cycle is equal to the fixed time multiplied by the minimum frequency, and the minimum value is less than 0.5.

[0011] In one 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 to receive a reference voltage and an output voltage, and subtract 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 to receive the difference voltage and perform 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 to receive the voltage parameter and generate a control frequency as a control parameter according to the voltage parameter, the maximum frequency and the minimum frequency.

[0012] In one embodiment of the present invention, the control frequency is represented by Fc, where Fc=(F min -F max )×P+F max , F min is the minimum frequency, F max is the maximum frequency, and P is the voltage parameter.

[0013] In one embodiment of the present invention, the voltage compensator is a proportional-integral-derivative controller (PID controller) or a proportional-integral controller (PI controller).

[0014] In one embodiment of the present invention, the resonant converter is a full-bridge resonant converter or a half-bridge resonant converter.

[0015] In one embodiment of the present invention, the minimum frequency and the maximum frequency are determined by the resonant tank of the resonant converter. The resonant tank is composed of a resonant inductor L R 1. Magnetizing Inductor L M and a resonating capacitor C R In series, the minimum frequency is greater than and less than Maximum frequency greater than

[0016] 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. The resonant control method includes the following steps: receiving a reference voltage and an output voltage, and using the reference voltage to perform voltage compensation on the output voltage to generate a control parameter; and receiving the control parameter, and determining whether the control parameter is less than a switching parameter: if so, generating a pulse modulation signal according to the control parameter and the switching parameter, thereby controlling the resonant converter to operate at a fixed time in each cycle of the pulse modulation signal, thereby adjusting the output voltage; and if not, generating a pulse frequency modulation signal 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.

[0017] In one embodiment of the present invention, the duty cycle of the pulse frequency modulation signal is 0.5.

[0018] In one 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 pulse frequency modulation signal is linearly inversely proportional to the output power.

[0019] In one embodiment of the present invention, the output voltage applies a load to generate an output current, and 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.

[0020] 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, and the maximum value of the duty cycle is 0.5, and the minimum value of the duty cycle is equal to the fixed time multiplied by the minimum frequency, and the minimum value is less than 0.5.

[0021] In one embodiment of the present invention, the switching parameter is equal to the maximum frequency, and the step of receiving a reference voltage and an output voltage and performing voltage compensation on the output voltage using the reference voltage to generate a control parameter includes the following steps: receiving the reference voltage and the output voltage, subtracting the reference voltage from the output 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 and generating a control frequency as a control parameter based on the voltage parameter, the maximum frequency and the minimum frequency.

[0022] In one embodiment of the present invention, the control frequency is represented by Fc, where Fc=(F min -F max )×P+F max , F min is the minimum frequency, F max is the maximum frequency, and P is the voltage parameter.

[0023] In one embodiment of the present invention, the minimum frequency and the maximum frequency are determined by the resonant tank of the resonant converter. The resonant tank is composed of a resonant inductor L R 1. Magnetizing Inductor L M and a resonating capacitor C R In series, the minimum frequency is greater than and less than Maximum frequency greater than

[0024] Based on the above, the resonant control device and the resonant control method thereof set a switching parameter without increasing the hardware cost, and perform a constant on-time (COT) modulation mode or a pulse frequency modulation mode according to the switching parameter to improve the light load efficiency of the resonant converter, reduce the starting 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 a control frequency so that it is linearly inversely proportional to the voltage parameter to improve the stability of the change amount of the control parameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 1 is a circuit diagram of a resonant converter in the prior art.

[0026] Figure 2 FIG. 1 is a graph showing the relative output power of the duty cycle and frequency of a pulse modulation signal in the prior art.

[0027] Figure 3 FIG. 4 is a circuit diagram of a resonance control device and a resonance converter according to a first embodiment of the present invention.

[0028] Figure 4 FIG. 4 is a graph showing the duty cycle and frequency of a pulse modulation signal relative to output power according to an embodiment of the present invention.

[0029] Figure 5 FIG. 4 is a waveform diagram of a pulse modulation signal in a pulse frequency modulation mode according to an embodiment of the present invention.

[0030] Figure 6 FIG. 4 is a waveform diagram of a pulse modulation signal in a constant on-time mode according to an embodiment of the present invention.

[0031] Figure 7 FIG. 4 is a flow chart of a resonance control method according to an embodiment of the present invention.

[0032] Figure 8FIG. 4 is a circuit diagram of a resonance control device and a resonance converter according to a second embodiment of the present invention.

[0033] Fig. 9 FIG. 4 is a flow chart of generating control parameters according to an embodiment of the present invention.

[0034] Explanation of reference numerals: 1-resonant converter; 10-signal controller; 11-first electronic switch; 12-second electronic switch; 13-resonant tank; 14-transformer; 15-load; 2-resonant 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 end; VL-low voltage end; Vo-output voltage; Io-output current; D-duty cycle; d-threshold value; F-frequency; W-output power; f1-minimum frequency; f2-maximum frequency; V-output voltage; I-output current; S-reference voltage; C-control parameter; P and P'-pulse modulation signals; Fmax-maximum frequency; Fmin-minimum frequency; M-minimum value; T-fixed time; L R -Resonant inductance; L M -Magnetic inductance; C R -resonant capacitor; S10, S12, S14, S16, S100, S101, S102-steps. DETAILED DESCRIPTION

[0035] The embodiments of the present invention will be further explained below with reference to the accompanying drawings. As much as possible, the same reference numerals represent the same or similar components in the drawings and the specification. In the drawings, shapes and thicknesses may be exaggerated for simplicity and convenience. It is understood that the components not specifically shown in the drawings or described in the specification are known to those skilled in the art. Those skilled in the art may make various changes and modifications based on the contents of the present invention.

[0036] When a component is referred to as being "on", it can generally mean that the component is directly on other components, or there can be other components between the two. Conversely, when a component is referred to as being "directly on" another component, there can be no other components between the two. As used herein, the term "and / or" includes any combination of one or more of the listed associated items.

[0037] The description of "one embodiment" or "an embodiment" in the following text refers to a specific component, structure or feature associated with at least one embodiment. Therefore, multiple descriptions of "one embodiment" or "an embodiment" appearing in multiple places in the following text do not refer to the same embodiment. Furthermore, specific components, structures and features in one or more embodiments can be combined in an appropriate manner.

[0038] The disclosure is particularly described with the following examples, which are for illustration only, because for those skilled in the art, various changes and modifications can be made without departing from the spirit and scope of the disclosure, so the protection scope of the disclosure should be determined by the scope of the attached patent. Throughout the specification and the scope of the patent, unless the content clearly specifies, the meaning of "a" and "the" includes such a description including "one or at least one" of the components or ingredients. In addition, as used in the disclosure, unless it is obvious from the specific context that the plurality is excluded, the singular article also includes the description of plural components or ingredients. Moreover, when used in this description and the following entire scope of the patent, unless the content clearly specifies, the meaning of "in which" may include "in which" and "on which". The terms used in the specification and the scope of the patent generally have the ordinary meaning of each term used in this field, in the content of this disclosure and in the specific content unless otherwise specified. Certain terms used to describe the present disclosure will be discussed below or elsewhere in this specification to provide practitioners with additional guidance in describing the present disclosure. The use of examples anywhere throughout the specification, including examples of any term discussed herein, is for illustrative purposes only and certainly does not limit the scope and meaning of the present disclosure or any exemplified term. Likewise, the present disclosure is not limited to the various embodiments set forth in this specification.

[0039] In addition, if the term "electrically coupled" or "electrically coupled" is used, it includes any direct and indirect electrical coupling means. For example, if a first device is described as being 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. In addition, if the transmission or provision of an electrical signal is described, a person skilled in the art should understand that the transmission process of the electrical signal may be accompanied by attenuation or other non-ideal changes, but the source and receiving end of the transmission or provision of the electrical signal should be considered to be substantially the same signal unless otherwise specified. For example, if an electrical signal S is transmitted (or provided) from terminal A of an electronic circuit to terminal B of the electronic circuit, a voltage drop may be generated through the source and drain of a transistor switch and / or possible stray capacitance, but if the purpose of this design is not to intentionally use the attenuation or other non-ideal changes generated during the transmission (or provision) to achieve certain specific technical effects, the electrical signal S should be considered to be substantially the same signal at terminal A and terminal B of the electronic circuit.

[0040] It is understood that the terms "comprising", "including", "having", "containing", "involving", etc. used herein are open-ended, that is, they include but are not limited to. In addition, any embodiment or patent application of the present invention does not necessarily achieve all the objects, advantages or features disclosed in the present invention. In addition, the abstract part and the title are only used to assist in searching patent documents, and are not used to limit the scope of the patent application of the invention.

[0041] Figure 3 FIG. 4 is a circuit diagram of a resonance control device and a resonance converter according to a first embodiment of the present invention. Figure 4 FIG. 4 is a graph showing the duty cycle and frequency of a pulse modulation signal relative to output power according to an embodiment of the present invention. Figure 5 FIG. 4 is a waveform diagram of a pulse modulation signal in a pulse frequency modulation mode according to an embodiment of the present invention. Figure 6 FIG. 1 is a waveform diagram of a pulse modulation signal in a constant on-time mode according to an embodiment of the present invention. Figure 3 and Figure 4, the following introduces the resonance control device 2 of 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 the output end of a resonant converter 3, and the output end is coupled to a load 4. The load 4 has an output voltage V. The output voltage V is applied to the load 4 to generate an output current I. The output current I and the output voltage V form an output power W. The resonant converter 3 can be a full-bridge resonant converter (full-bridge resonate converter) or a half-bridge resonant converter (half-bridge resonate converter). The feedback controller 20 is used to receive a reference voltage S and an output voltage V, and use 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 to receive the control parameter C, and generate pulse modulation signals P and P' based on the switching parameter, and drive the resonant converter 3 to adjust the output voltage V through the pulse modulation signals P and P'. The pulse modulation signals P and P' have F max The maximum frequency expressed in F min Indicates the minimum frequency, maximum frequency F max Corresponding to the 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 the pulse frequency modulation (PFM) mode. When the control parameter C is less than the switching parameter, the pulse modulation signals P and P' control the resonant converter 3 to operate at a fixed time in each cycle of the pulse modulation signals P and P', so that the resonant converter 3 performs the constant on-time (COT) mode.

[0042] 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 to receive the pulse modulation signals P and P', thereby driving the transformer 32 through the resonant tank 31, thereby changing the output voltage V. For example, the minimum frequency F min With the maximum frequency F max The resonant tank 31 of the resonant converter 3 is determined by a resonant inductor L R 1. Magnetizing Inductor L M and a resonating capacitor C R In series, minimum frequency F min Greater than and less than Maximum frequency F max Greater than

[0043] like Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the duty cycle of the pulse frequency modulation signal can be fixed to 0.5, and the frequency F of the pulse frequency modulation signal is linearly inversely proportional to the output power W. The maximum value of the frequency F is the maximum frequency F max , the minimum value of frequency F is the minimum frequency F min The two pulse frequency modulation signals do not have high voltage levels 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 , then the pulse frequency modulation signal has a minimum value M of the duty cycle D. When the control parameter C is less than the switching parameter, the frequency 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 frequency F of the pulse modulation signals P and P' are respectively the maximum frequency F max With 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 fixed time T of the operation of the resonant converter 3 multiplied by the minimum frequency F min , and the minimum value M of the duty cycle D is less than 0.5. Generally speaking, this fixed time T is the shortest period of operation of the resonant converter 3 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 cycle D. Figure 6 As shown, 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 voltage levels at the same time to avoid burning the circuit. The resonant control device sets the switching parameters without increasing the hardware cost, and performs a constant on-time modulation mode or a pulse frequency modulation mode according to the switching parameters to improve the light-load efficiency of the resonant converter 3, reduce the starting resonant 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 pulse width modulation mode cannot cover. Therefore, the resonant control device 2 can increase the lower limit range of the output voltage of the resonant converter 3 and expand the operating range of this output voltage, and reduce the number of times the burst mode is executed.

[0044] Figure 7 This is a flow chart of a resonance control method according to an embodiment of the present invention. Figure 3 and Figure 7, the following describes a resonant control method of a resonant control device 2 according to an embodiment of the present invention. First, as shown in step S10, the feedback controller 20 receives a reference voltage S and an output voltage V, and uses the reference voltage S to perform voltage compensation on the output voltage V to generate a control parameter C. As shown in step S12, the processor 21 receives the control parameter C, and determines whether the control parameter C is less than the switching parameter. If so, as shown in step S14, the processor 21 generates pulse modulation signals P and P' according to the control parameter C and the switching parameter, thereby controlling the resonant converter 3 to operate at a fixed time in each cycle of the pulse modulation signal P or P', thereby adjusting 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, thereby driving the resonant converter 3 to adjust the output voltage V.

[0045] Please refer to Figure 3 and Figure 4 . When the load 4 becomes lighter, the control parameter C becomes smaller. When the control parameter C is less than the switching parameter, the processor 21 generates pulse modulation signals P and P' to control the resonant converter 3 to operate at a fixed time in each cycle of the pulse modulation signal P or P', thereby adjusting 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 to drive the resonant converter 3 to adjust the output voltage V. The frequency F of the pulse frequency modulation signal depends on the output power W, and the duty cycle D of the pulse frequency modulation signal is fixed at 0.5. In addition, the reference voltage S can also be changed 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 less than the switching parameter, the processor 21 generates the pulse modulation signals P and P', thereby controlling the resonant converter 3 to operate at a fixed time in each cycle of the pulse modulation signal P or P', thereby adjusting 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 increases. 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, thereby driving the resonant converter 3 to adjust the output voltage V. The frequency F of the pulse frequency modulation signal depends on the output power W, and the duty cycle D of the pulse frequency modulation signal is fixed at 0.5.

[0046] Figure 8 FIG. 4 is a circuit diagram of a resonance control device and a resonance converter according to a second embodiment of the present invention. Fig. 9 This is a flow chart of generating control parameters according to an embodiment of the present invention. Figure 8and Fig. 9 , the following describes the resonance control device 2 of 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. The remaining technical features are the same as those of the first embodiment and are not described in detail 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 a reference voltage S and an 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 thereon 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 parameter VD according to the voltage parameter VP and the maximum frequency F max With minimum frequency F min A control frequency is generated as the control parameter C. In some embodiments of the present invention, the control frequency is represented by Fc, Fc=(F min -F max )×P+F max , P is the voltage parameter. Since the control frequency is in inverse linear proportion to the voltage parameter, the stability of the change in the control parameter C can be improved.

[0047] According to the above embodiments, the resonant control device and the resonant control method thereof set a switching parameter without increasing the hardware cost, and perform a constant on-time modulation mode or a pulse frequency modulation mode according to the switching parameter to improve the light load efficiency of the resonant converter, reduce the starting 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 a control frequency so that it is linearly inversely proportional to the voltage parameter to improve the stability of the change amount of the control parameter.

[0048] 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 equivalent changes and modifications made according to the shape, structure, characteristics and spirit described in the claims of the present invention should be included in the scope of protection required by the claims of the present invention.

Claims

1. A resonance control device, characterized in that: include: a feedback controller coupled to an output terminal of a resonant converter, the output terminal being coupled to a load, the load having an output voltage, wherein the feedback controller is used to receive a reference voltage and the output voltage, and perform voltage compensation on the output voltage using the reference voltage to generate a control parameter; as well as a processor coupled to the feedback controller and the resonant converter and presetting a switching parameter, the processor being used to receive the control parameter, and to generate a pulse modulation signal based on the control parameter and the switching parameter, and to drive the resonant converter to adjust the output voltage through the pulse modulation signal, the pulse modulation signal having a maximum frequency and a minimum frequency, the maximum frequency corresponding 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, and when the control parameter is less than the switching parameter, the pulse modulation signal controls the resonant converter to operate at a fixed time in each cycle of the pulse modulation signal; 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 less than the switching parameter, the frequency of the pulse modulation signal is linearly proportional to the output power.

2. The resonance control device according to claim 1, characterized in that: The duty cycle of the pulse frequency modulation signal is 0.

5.

3. The resonance control device according to claim 2, characterized in that: The frequency of the pulse frequency modulation signal is linearly inversely proportional to the output power.

4. The resonance control device according to claim 1, characterized in that: 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 minimum value of the duty cycle is equal to the fixed time multiplied by the minimum frequency, and the minimum value is less than 0.

5.

5. The resonance control device according to claim 1, characterized in that: The switching parameter is equal to the maximum frequency, and the feedback controller includes: a subtractor coupled to the output terminal, wherein the subtractor is used to receive the reference voltage and the output voltage, and subtract the output voltage from the reference voltage to obtain a difference voltage; a voltage compensator coupled to the subtractor, wherein the voltage compensator is used to receive the difference voltage and perform voltage compensation thereon to generate a voltage parameter; and A digital voltage-controlled oscillator is coupled to the voltage compensator and the processor, wherein the digital voltage-controlled oscillator is used to receive the voltage parameter and generate a control frequency as the control parameter according to the voltage parameter, the maximum frequency and the minimum frequency.

6. The resonance control device according to claim 5, characterized in that: The control frequency is represented by Fc, Fc=(F min -F max )×P+F max , F min is the minimum frequency, F max is the maximum frequency, and P is the voltage parameter.

7. The resonance control device according to claim 5, characterized in that: The voltage compensator is a proportional-integral-derivative controller or a proportional-integral controller.

8. The resonance control device according to claim 1, characterized in that: The resonant converter is a full-bridge resonant converter or a half-bridge resonant converter.

9. The resonance control device according to claim 1, characterized in that: The minimum frequency and the maximum frequency are determined by the resonant tank of the resonant converter. The resonant tank is composed of a resonant inductor L R , a magnetizing inductance L M With a resonant capacitor C R in series, the minimum frequency is greater than and less than The maximum frequency is greater than 10. A resonance control method, which controls a resonance converter, wherein the resonance converter is coupled to a load, and the load has an output voltage, characterized in that: The resonance control method comprises the following steps: receiving a reference voltage and the output voltage, and performing voltage compensation on the output voltage using the reference voltage to generate a control parameter; and Receiving the control parameter, and determining whether the control parameter is less than a switching parameter: If yes, a pulse modulation signal is generated according to the control parameter and the switching parameter, so as to control the resonant converter to operate at a fixed time in each cycle of the pulse modulation signal, thereby adjusting the output voltage; and If not, generating a pulse frequency modulation signal according to the control parameter and the switching parameter to drive 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; 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 less than the switching parameter, the frequency of the pulse modulation signal is linearly proportional to the output power.

11. The resonance control method according to claim 10, characterized in that: The duty cycle of the pulse frequency modulation signal is 0.

5.

12. The resonance control method according to claim 10, characterized in that: The frequency of the pulse frequency modulation signal is linearly inversely proportional to the output power.

13. The resonance control method according to claim 10, characterized in that: 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 minimum value of the duty cycle is equal to the fixed time multiplied by the minimum frequency, and the minimum value is less than 0.

5.

14. The resonance control method according to claim 10, characterized in that: The switching parameter is equal to the maximum frequency, and the step of receiving the reference voltage and the output voltage and performing voltage compensation on the output voltage using the reference voltage to generate the control parameter includes the following steps: receiving the reference voltage and the output voltage, and 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; as well as The voltage parameter is received, and a control frequency as the control parameter is generated according to the voltage parameter, the maximum frequency and the minimum frequency.

15. The resonance control method according to claim 14, characterized in that: The control frequency is represented by Fc, Fc=(F min -F max )×P+F max , F min is the minimum frequency, F max is the maximum frequency, and P is the voltage parameter.

16. The resonance control method according to claim 10, characterized in that: The minimum frequency and the maximum frequency are determined by the resonant tank of the resonant converter. The resonant tank is composed of a resonant inductor L R , a magnetizing inductance L M With a resonant capacitor C R in series, the minimum frequency is greater than and less than The maximum frequency is greater than

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