阅读说明：本技术 一种延长电路输出保持时间的方法、系统及串联谐振设备 (Method and system for prolonging output holding time of circuit and series resonance equipment ) 是由 郑洲廷 于 2020-04-23 设计创作，主要内容包括：本发明公开了一种延长电路输出保持时间的方法、系统及串联谐振设备。考虑到串联谐振电路的电压增益值和激磁电感与谐振电感的比例有关,具体是激磁电感与谐振电感的比例越小,电压增益值越高,所以串联谐振电路设置为激磁电感与谐振电感的比例可调的电路结构,且在电路处于工作状态时,调整激磁电感与谐振电感的比例大于第一比例阈值,此时电路功率损耗较小,可满足低功率损耗要求；在电路进入关机状态时,调整激磁电感与谐振电感的比例小于第二比例阈值,此时电压增益值较高,可延长电路的输出电压保持时间,以使电路满足关机保持时间要求。可见,本申请可兼顾电路高效率问题及高保持时间问题,从而提升了电路的供电性能。(The invention discloses a method and a system for prolonging circuit output holding time and series resonance equipment. Considering that the voltage gain value of the series resonant circuit is related to the ratio of the excitation inductor to the resonant inductor, specifically, the smaller the ratio of the excitation inductor to the resonant inductor is, the higher the voltage gain value is, so that the series resonant circuit is set to be a circuit structure with adjustable ratio of the excitation inductor to the resonant inductor, and when the circuit is in a working state, the ratio of the excitation inductor to the resonant inductor is adjusted to be larger than a first ratio threshold value, and at the moment, the power loss of the circuit is smaller, and the requirement of low power loss can be met; when the circuit enters a shutdown state, the ratio of the excitation inductor to the resonance inductor is adjusted to be smaller than a second ratio threshold, and at the moment, the voltage gain value is higher, so that the output voltage holding time of the circuit can be prolonged, and the circuit meets the shutdown holding time requirement. Therefore, the problem of high efficiency and high retention time of the circuit can be considered, and the power supply performance of the circuit is improved.)

1. A method for prolonging the output holding time of a circuit is characterized in that the method is applied to a series resonant circuit with adjustable proportion of excitation inductance and resonant inductance, and comprises the following steps:

judging whether the series resonance circuit enters a shutdown state or not;

if not, adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value so that the power loss of the series resonance circuit meets the preset low-power loss requirement;

if so, adjusting the ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold value so that the output voltage holding time of the series resonance circuit meets the preset shutdown holding time requirement; wherein the preset first proportion threshold is greater than or equal to the preset second proportion threshold.

2. The method of extending circuit output hold time of claim 1 wherein determining whether the series resonant circuit enters a shutdown state comprises:

detecting whether an AC input power of the series resonant circuit is L oss;

if so, determining that the series resonant circuit enters a shutdown state;

if not, determining that the series resonant circuit does not enter a shutdown state.

3. The method for extending circuit output hold time of claim 1, wherein the series resonant circuit is a series resonant circuit with adjustable inductance of a resonant inductor;

correspondingly, the process of adjusting the ratio of the excitation inductance to the resonance inductance includes:

and adjusting the ratio of the exciting inductor to the resonant inductor by adjusting the inductance value of the resonant inductor.

4. A method of extending circuit output hold time as defined in claim 3, wherein said resonant inductor comprises a main inductor and an auxiliary inductor connected in series with said main inductor and in parallel with a controllable switch;

correspondingly, the process of adjusting the ratio of the excitation inductance to the resonance inductance to be larger than the preset first ratio threshold includes:

controlling the controllable switch to be conducted so as to adjust the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value;

adjusting the ratio of the excitation inductance to the resonance inductance to be smaller than a preset second ratio threshold, comprising:

and controlling the controllable switch to be switched off so as to adjust the ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold value.

5. Method for extending the output hold time of a circuit according to claim 4, characterized in that the controllable switch is embodied as a power crystal or a relay.

6. The method for prolonging circuit output retention time according to any one of claims 1-5, wherein the step of adjusting the ratio of the excitation inductance to the resonance inductance to be greater than a preset first ratio threshold comprises:

and adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold and smaller than a preset third ratio threshold so that the series resonance circuit is in a zero-voltage switching state when working in an LL C resonance mode, wherein the preset third ratio threshold is larger than the preset first ratio threshold.

7. A system for prolonging output holding time of a circuit is characterized in that the system is applied to a series resonant circuit with adjustable proportion of excitation inductance and resonant inductance, and comprises:

the judging module is used for judging whether the series resonance circuit enters a shutdown state or not; if not, executing a low-power adjusting module; if yes, executing a high retention time adjusting module;

the low-power adjusting module is used for adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value so that the power loss of the series resonance circuit meets the preset low-power loss requirement;

the high holding time adjusting module is used for adjusting the proportion of the exciting inductor to the resonance inductor to be smaller than a preset second proportion threshold value so that the holding time of the output voltage of the series resonance circuit meets the requirement of preset shutdown holding time; wherein the preset first proportion threshold is greater than or equal to the preset second proportion threshold.

8. The system for extending circuit output retention time of claim 7, wherein the series resonant circuit is specifically a series resonant circuit with an adjustable inductance value of a resonant inductor;

accordingly, the low power adjustment module and the high hold time adjustment module are both specifically configured to adjust the ratio of the excitation inductor to the resonant inductor by adjusting the inductance value of the resonant inductor.

9. The system for extending circuit output hold time of claim 8, wherein said resonant inductor comprises a main inductor and an auxiliary inductor connected in series with said main inductor and in parallel with a controllable switch;

correspondingly, the low-power adjusting module is specifically configured to control the controllable switch to be turned on, so as to adjust a ratio of the excitation inductor to the resonance inductor to be greater than a preset first ratio threshold;

the high holding time adjusting module is specifically configured to control the controllable switch to be turned off, so as to adjust a ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold.

10. A series resonant device, comprising:

the proportion of the excitation inductor to the resonance inductor is adjustable;

a control circuit connected to the series resonant circuit for, in operation, implementing the steps of the method of extending circuit output hold time as claimed in any one of claims 1 to 6.

Technical Field

The invention relates to the field of series resonance, in particular to a method and a system for prolonging circuit output holding time and series resonance equipment.

Background

Currently, there are many circuit architectures for providing power to a load, such as an HB-SRC (half-bridge series resonant) circuit architecture shown in fig. 1, in which the HB-SRC circuit utilizes power transistors SW1 and SW2 that are conducted alternately to transfer the power from an input power Vin to an output load Vo through a resonant tank and a transformer T1. Power based on HB-SRC circuitAs can be seen from the voltage gain frequency response, when the HB-SRC circuit operates in the LL C resonant mode, the voltage gain is greater than 1 (the voltage gain value is related to the circuit operating frequency), but the higher the voltage gain, the higher the current I of the exciting inductor L m_LmThe larger the circuit power loss will be. In the prior art, generally, in order to ensure the high efficiency of the series resonant circuit, the voltage gain of the series resonant circuit is limited so as to avoid power loss caused by excessive internal consumption circulating current, but this method may result in a short holding time of the output voltage of the circuit itself when the circuit is shut down, i.e., the problem of high holding time of the output voltage of the circuit is difficult to be considered when the problem of high efficiency of the series resonant circuit is solved, thereby affecting the power supply performance of the circuit.

Therefore, how to provide a solution to the above technical problem is a problem that needs to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a method and a system for prolonging the output holding time of a circuit and series resonance equipment, which can take the problems of high efficiency and high holding time of the circuit into consideration, thereby improving the power supply performance of the circuit.

In order to solve the above technical problem, the present invention provides a method for prolonging a circuit output retention time, which is applied to a series resonant circuit with adjustable ratio of an excitation inductor and a resonant inductor, and comprises:

judging whether the series resonance circuit enters a shutdown state or not;

if not, adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value so that the power loss of the series resonance circuit meets the preset low-power loss requirement;

if so, adjusting the ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold value so that the output voltage holding time of the series resonance circuit meets the preset shutdown holding time requirement; wherein the preset first proportion threshold is greater than or equal to the preset second proportion threshold.

Preferably, the process of determining whether the series resonant circuit enters the shutdown state includes:

detecting whether an AC input power of the series resonant circuit is L oss;

if so, determining that the series resonant circuit enters a shutdown state;

if not, determining that the series resonant circuit does not enter a shutdown state.

Preferably, the series resonant circuit is a series resonant circuit with an adjustable inductance value of a resonant inductor;

correspondingly, the process of adjusting the ratio of the excitation inductance to the resonance inductance includes:

and adjusting the ratio of the exciting inductor to the resonant inductor by adjusting the inductance value of the resonant inductor.

Preferably, the resonant inductor comprises a main inductor and an auxiliary inductor connected in series with the main inductor and connected in parallel with the controllable switch;

correspondingly, the process of adjusting the ratio of the excitation inductance to the resonance inductance to be larger than the preset first ratio threshold includes:

and controlling the controllable switch to be conducted so as to adjust the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value.

Adjusting the ratio of the excitation inductance to the resonance inductance to be smaller than a preset second ratio threshold, comprising:

and controlling the controllable switch to be switched off so as to adjust the ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold value.

Preferably, the controllable switch is embodied as a power crystal or a relay.

Preferably, the adjusting the ratio of the excitation inductance to the resonance inductance to be greater than a preset first ratio threshold includes:

and adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold and smaller than a preset third ratio threshold so that the series resonance circuit is in a zero-voltage switching state when working in an LL C resonance mode, wherein the preset third ratio threshold is larger than the preset first ratio threshold.

In order to solve the above technical problem, the present invention further provides a system for prolonging a circuit output retention time, which is applied to a series resonant circuit with adjustable ratio of an excitation inductor to a resonant inductor, and comprises:

the judging module is used for judging whether the series resonance circuit enters a shutdown state or not; if not, executing a low-power adjusting module; if yes, executing a high retention time adjusting module;

the low-power adjusting module is used for adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value so that the power loss of the series resonance circuit meets the preset low-power loss requirement;

the high holding time adjusting module is used for adjusting the proportion of the exciting inductor to the resonance inductor to be smaller than a preset second proportion threshold value so that the holding time of the output voltage of the series resonance circuit meets the requirement of preset shutdown holding time; wherein the preset first proportion threshold is greater than or equal to the preset second proportion threshold.

Preferably, the series resonant circuit is a series resonant circuit with an adjustable inductance value of a resonant inductor;

accordingly, the low power adjustment module and the high hold time adjustment module are both specifically configured to adjust the ratio of the excitation inductor to the resonant inductor by adjusting the inductance value of the resonant inductor.

Preferably, the resonant inductor comprises a main inductor and an auxiliary inductor connected in series with the main inductor and connected in parallel with the controllable switch;

correspondingly, the low-power adjusting module is specifically configured to control the controllable switch to be turned on, so as to adjust a ratio of the excitation inductor to the resonance inductor to be greater than a preset first ratio threshold.

The high holding time adjusting module is specifically configured to control the controllable switch to be turned off, so as to adjust a ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold.

In order to solve the above technical problem, the present invention also provides a series resonance apparatus, including:

the proportion of the excitation inductor to the resonance inductor is adjustable;

and the control circuit is connected with the series resonant circuit and is used for realizing the steps of any method for prolonging the output holding time of the circuit when in work.

The invention provides a method for prolonging the output holding time of a circuit, which is applied to a series resonant circuit. Considering that the voltage gain value of the series resonant circuit is related to the ratio of the excitation inductor to the resonant inductor, specifically, the smaller the ratio of the excitation inductor to the resonant inductor is, the higher the voltage gain value is, so the series resonant circuit of the present application is configured into a circuit structure with an adjustable ratio of the excitation inductor to the resonant inductor, and when the series resonant circuit is in a working state, the circuit power loss is small at this time, and the preset low power loss requirement can be met by adjusting the ratio of the excitation inductor to the resonant inductor to be larger than a preset first ratio threshold; when the series resonant circuit enters a shutdown state, the proportion of the excitation inductor to the resonant inductor is adjusted to be smaller than a preset second proportion threshold value (smaller than or equal to a preset first proportion threshold value), and at the moment, the voltage gain value is higher, so that the output voltage holding time of the circuit can be prolonged, and the circuit meets the requirement of preset shutdown holding time. Therefore, the problem of high efficiency and high retention time of the circuit can be considered, and the power supply performance of the circuit is improved.

The invention also provides a system for prolonging the output holding time of the circuit and series resonance equipment, and the system and the series resonance equipment have the same beneficial effects as the prolonging method.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed in the prior art and the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a prior art HB-SRC circuit architecture diagram;

FIG. 2 is a flowchart of a method for extending output retention time of a circuit according to an embodiment of the present invention;

FIG. 3 is a voltage gain frequency response graph of an HB-SRC circuit according to an embodiment of the present invention;

FIG. 4 is a timing diagram illustrating operations of the HB-SRC circuit in the SRC resonant mode according to the embodiment of the present invention;

FIG. 5 is a timing diagram illustrating the operation of the HB-SRC circuit operating in the LL C resonant mode according to the embodiment of the present invention;

fig. 6 is a schematic diagram of peak gain of a HB-SRC circuit operating in the LL C resonant mode with K equal to 1 according to an embodiment of the present invention;

fig. 7 is a schematic diagram of peak gain of K-8 when the HB-SRC circuit operates in the LL C resonant mode according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a system for prolonging a circuit output holding time according to an embodiment of the present invention.

Detailed Description

The core of the invention is to provide a method, a system and a series resonance device for prolonging the output holding time of a circuit, which can give consideration to the problems of high efficiency and high holding time of the circuit, thereby improving the power supply performance of the circuit.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 2, fig. 2 is a flowchart illustrating a method for prolonging a circuit output retention time according to an embodiment of the present invention.

The method for prolonging the output holding time of the circuit is applied to a series resonance circuit with adjustable proportion of excitation inductance and resonance inductance, and comprises the following steps:

step S1: judging whether the series resonance circuit enters a shutdown state or not; if not, go to step S2; if yes, go to step S3.

Step S2: and adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value so as to enable the power loss of the series resonance circuit to meet the preset low-power loss requirement.

Step S3: and adjusting the ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold value so that the output voltage holding time of the series resonance circuit meets the requirement of preset shutdown holding time.

It should be noted that the preset of the present application is set in advance, and only needs to be set once, and the reset is not needed unless the modification is needed according to the actual situation. Wherein the preset first proportion threshold is greater than or equal to the preset second proportion threshold.

Specifically, firstly, the operation analysis is performed on a Series resonant circuit (such as an HB-SRC circuit), wherein a voltage gain frequency response curve of the HB-SRC circuit is shown in FIG. 3, when the circuit operates in a Region of Region-3, a resonant tank presents a capacitive characteristic and a current lead voltage, upper and lower bridge power crystals SW1 and SW2 have a characteristic of zero current cutoff and are suitable for a framework with low-voltage and high-current input, when the circuit operates in a Region of Region-1 and Region-2, the resonant tank presents an inductive characteristic and a voltage lead current, and upper and lower bridge power crystals SW1 and SW2 have a characteristic of zero voltage switching and are suitable for a framework with high-voltage and low-current input, so as to distinguish the Region of Region-1 and Region-2, when the circuit operates in the Region of Region-1, the circuit is called to operate in an SRC (Series resonant converter) resonant mode, and when the circuit operates in the Region of Region-2, the circuit is called to operate in a LL C resonant mode.

When the circuit operates in the SRC resonance mode, the resonant tank is composed of a resonant inductor L r, a resonant capacitor Cr and an output reflective load, the first resonant frequency Fr is determined by the resonant inductor L r and the resonant capacitor Cr, when the operating frequency changes, the equivalent impedance of the resonant tank changes, the output load and the resonant tank are connected in series, the output voltage and the input voltage are in a voltage division relationship, therefore, if the turns ratio of the transformer T1 is 1:1:1, the voltage gain of the circuit is necessarily less than or equal to 1, when the operating frequency is equal to the resonant frequency Fr, the impedance of the resonant inductor L r and the impedance of the resonant capacitor Cr cancel each other, the equivalent impedance of the resonant tank is equal to zero, and the input voltage is fully across the output load,it should be further noted that, when the circuit operates in the SRC resonance mode, the exciting inductor L m of the transformer T1 does not participate in resonance, the zero voltage switching condition of the upper and lower bridge power crystals SW1 and SW2 is related to the output load current, and the operation timing diagram of the circuit is shown in FIG. 4 (V is shown in FIG. 4) (the voltage gain of the circuit is 1, so the maximum voltage gain of the circuit occurs when the operating frequency is equal to the resonance frequency Fr)_GS1Is the drive signal for power crystal SW 1; v_GS2Is a drive signal of a power crystal SW2, I_LrCurrent of the resonant inductor L r).

When the circuit operates in a LL C resonant mode, the resonant tank is composed of a resonant inductor L r, a resonant capacitor Cr, an excitation inductor L m and an output reflective load, resonance is added to the excitation inductor L m in the interval, the excitation inductor L m and the resonant inductor L r generate a second resonant frequency Fm., when the operating frequency enters a Region of Region-2, the current of the resonant inductor L r oscillates to be the same as the current of the excitation inductor L m, the resonant tank is added with the excitation inductor L m to generate a new resonant frequency, at the moment, the resonant component comprises three components of a resonant inductor L r, a resonant capacitor Cr and an excitation inductor L m, as shown in FIG. 5, after the operating in a Region of T2-T4, the current of the resonant inductor L r is replaced by the current of the excitation inductor L m, as shown in FIG. 3, the circuit operates in a Region of Region-2 and operates in a Region of Region-1 with the maximum difference in a Region of voltage gain of SW1 and the circuit is greater than the voltage of SW1, the crystal SW1, and the power of SW1 and the crystal is switched to the voltage of SW 29I, the crystal under the power bridge under the power-2_LmIndependently of the output load current, i.e., the current across the excitation inductor L m is large enough to cause zero voltage switching.

It can be seen that when the circuit works in the Region-2, the voltage gain of the circuit is greater than 1, but the higher the voltage gain is, the higher the current I of the exciting inductor L m_LmThe larger the circuit power loss will be. In the prior art, generally, in order to ensure high efficiency of a series resonant circuit, the voltage gain of the series resonant circuit is limited so as to avoid power loss caused by excessive internal consumption circulating current, but this method may result in a short holding time of the output voltage of the circuit itself when the circuit is shut down, thereby affecting the power supply performance of the circuit.

Based on this, considering that the voltage gain value of the series resonant circuit is related to the ratio of the excitation inductor L m to the resonant inductor L r, and K is L m/L r, as shown in fig. 6 and 7, if the K value is smaller, the voltage gain is higher, so the technical means adopted by the application is that the series resonant circuit is set to be a circuit structure with adjustable ratio of the excitation inductor L m to the resonant inductor L r, and when the series resonant circuit is in an operating state, the ratio of the excitation inductor L m to the resonant inductor L r is adjusted to be larger than a preset first ratio threshold, that is, the K value is larger, and then the current I of the excitation inductor L m is larger_LmWhen the series resonant circuit enters a shutdown state, the ratio of the exciting inductor L m to the resonant inductor L r is adjusted to be smaller than a preset second ratio threshold value, namely the K value is smaller, the voltage gain value is increased, the output voltage of the circuit can be stabilized, and therefore the output voltage holding time of the circuit is prolonged, so that the circuit meets the preset shutdown holding time requirement.

The invention provides a method for prolonging the output holding time of a circuit, which is applied to a series resonant circuit. Considering that the voltage gain value of the series resonant circuit is related to the ratio of the excitation inductor to the resonant inductor, specifically, the smaller the ratio of the excitation inductor to the resonant inductor is, the higher the voltage gain value is, so the series resonant circuit of the present application is configured into a circuit structure with an adjustable ratio of the excitation inductor to the resonant inductor, and when the series resonant circuit is in a working state, the circuit power loss is small at this time, and the preset low power loss requirement can be met by adjusting the ratio of the excitation inductor to the resonant inductor to be larger than a preset first ratio threshold; when the series resonant circuit enters a shutdown state, the proportion of the excitation inductor to the resonant inductor is adjusted to be smaller than a preset second proportion threshold value (smaller than or equal to a preset first proportion threshold value), and at the moment, the voltage gain value is higher, so that the output voltage holding time of the circuit can be prolonged, and the circuit meets the requirement of preset shutdown holding time. Therefore, the problem of high efficiency and high retention time of the circuit can be considered, and the power supply performance of the circuit is improved.

On the basis of the above-described embodiment:

as an alternative embodiment, the process of determining whether the series resonant circuit enters the shutdown state includes:

detecting whether an AC input power of the series resonant circuit is L oss;

if so, determining that the series resonant circuit enters a shutdown state;

if not, determining that the series resonant circuit does not enter a shutdown state.

Specifically, considering that an AC (alternating current) input power L oss of the series resonant circuit is lost when the series resonant circuit enters a shutdown state from an operating state, the present application determines whether the series resonant circuit enters the shutdown state by detecting the AC input power of the series resonant circuit, specifically, determines that the series resonant circuit enters the shutdown state when detecting an AC input power L oss of the series resonant circuit, and determines that the series resonant circuit does not enter the shutdown state, that is, the series resonant circuit is in the operating state when detecting that the AC input power of the series resonant circuit exists.

As an optional embodiment, the series resonant circuit is specifically a series resonant circuit with an adjustable inductance value of a resonant inductor;

correspondingly, the process of adjusting the ratio of the excitation inductance to the resonance inductance comprises the following steps:

the ratio of the exciting inductance to the resonant inductance is adjusted by adjusting the inductance value of the resonant inductance.

Specifically, the ratio of the exciting inductor L m to the resonant inductor L r can be changed in three ways, namely, 1) only changing the inductance value of the exciting inductor L m, 2) only changing the inductance value of the resonant inductor L r, and 3) simultaneously changing the inductance value of the exciting inductor L m and the inductance value of the resonant inductor L r.

As an alternative embodiment, the resonant inductor comprises a main inductor and an auxiliary inductor connected in series with the main inductor and in parallel with the controllable switch;

correspondingly, the process of adjusting the ratio of the excitation inductance to the resonance inductance to be greater than the preset first ratio threshold includes:

and controlling the controllable switch to be conducted so as to adjust the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold value.

The process of adjusting the ratio of the excitation inductance to the resonance inductance to be smaller than a preset second ratio threshold value comprises the following steps:

and controlling the controllable switch to be switched off so as to adjust the proportion of the excitation inductor and the resonance inductor to be smaller than a preset second proportion threshold value.

Specifically, the circuit architecture with the inductance value adjustable by the resonant inductor L r is that the resonant inductor L r includes a main inductor L0 r1 and an auxiliary inductor L r2 connected in series with the main inductor L r1, and a controllable switch is connected in parallel with the auxiliary inductor L r 2. when the series resonant circuit is in an operating state, the controllable switch is controlled to be on, at this time, the inductance value of the resonant inductor L r of the series resonant circuit is equal to the inductance value of the main inductor L r1, that is, the resonant inductance value of the series resonant circuit is smaller, and for the ratio K of the exciting inductor L m to the resonant inductor L r, K is larger, specifically, the value K is larger than a preset first ratio threshold, and then the current I of the exciting inductor L m is larger_LmWhen the series resonant circuit enters a shutdown state, the controllable switch is controlled to be switched off, at the moment, the inductance value of the resonant inductor L r of the series resonant circuit is equal to the inductance value of the main inductor L r1 plus the inductance value of the auxiliary inductor L r2, namely the resonant inductance value of the series resonant circuit takes a larger value, and for the proportion K of the exciting inductor L m to the resonant inductor L r, the K takes a smaller value, specifically the K is smaller than a preset second proportion threshold value, the voltage gain value is increased, and the output voltage holding time of the circuit can be prolonged, so that the circuit meets the preset shutdown holding time requirement.

As an alternative embodiment, the controllable switch is embodied as a power crystal or a relay.

Specifically, the controllable switch of the present application may be a power crystal, or may also be a controllable switching device such as a relay, and the present application is not particularly limited herein.

As an alternative embodiment, the process of adjusting the ratio of the excitation inductance to the resonance inductance to be greater than the preset first ratio threshold includes:

and adjusting the ratio of the excitation inductor to the resonance inductor to be larger than a preset first ratio threshold and smaller than a preset third ratio threshold so that the series resonance circuit is in a zero-voltage switching state when working in an LL C resonance mode, wherein the preset third ratio threshold is larger than the preset first ratio threshold.

In particular, when the series resonant circuit is considered to work in the LL C resonant mode, the zero-voltage switching condition of the power crystal and the exciting inductance current I in the series resonant circuit are considered_LmIn a related way, when the current on the exciting inductor L m is large enough, the zero-voltage switching of the power crystal can be realized, and when the ratio K of the exciting inductor L m to the resonant inductor L r is smaller, the current on the exciting inductor L m is larger, so that when the ratio K of the exciting inductor L m to the resonant inductor L r is adjusted to be larger than a preset first ratio threshold, the condition that the ratio K of the exciting inductor L m to the resonant inductor L r is smaller than a preset third ratio threshold is also met, so that the current on the exciting inductor L m is enough to enable the power crystal in the series resonant circuit to realize the zero-voltage switching when the series resonant circuit works in an L0C resonant mode, namely, the preset low-power loss requirement is met, and the zero-voltage switching requirement when the circuit works in a LL C resonant mode is also met.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a system for prolonging a circuit output retention time according to an embodiment of the present invention.

The system for prolonging the output holding time of the circuit is applied to a series resonance circuit with adjustable proportion of excitation inductance and resonance inductance, and comprises:

the judging module 1 is used for judging whether the series resonant circuit enters a shutdown state or not; if not, executing the low-power adjusting module 2; if yes, executing a high retention time adjusting module 3;

the low-power adjusting module 2 is used for adjusting the ratio of the excitation inductance to the resonance inductance to be larger than a preset first ratio threshold value so that the power loss of the series resonance circuit meets the preset low-power loss requirement;

the high holding time adjusting module 3 is used for adjusting the ratio of the excitation inductor to the resonance inductor to be smaller than a preset second ratio threshold value so as to enable the holding time of the output voltage of the series resonance circuit to meet the requirement of preset shutdown holding time; wherein the preset first proportion threshold is greater than or equal to the preset second proportion threshold.

As an optional embodiment, the series resonant circuit is specifically a series resonant circuit with an adjustable inductance value of a resonant inductor;

accordingly, the low power adjustment module 2 and the high holding time adjustment module 3 are both specifically configured to adjust the ratio of the excitation inductor to the resonance inductor by adjusting the inductance value of the resonance inductor.

As an alternative embodiment, the resonant inductor comprises a main inductor and an auxiliary inductor connected in series with the main inductor and in parallel with the controllable switch;

correspondingly, the low power adjustment module 2 is specifically configured to control the controllable switch to be turned on, so as to adjust a ratio of the excitation inductance to the resonance inductance to be greater than a preset first ratio threshold.

The high retention time adjustment module 3 is specifically configured to control the controllable switch to turn off, so as to adjust a ratio of the excitation inductance to the resonance inductance to be smaller than a preset second ratio threshold.

For introduction of the system provided in the present application, reference is made to the embodiments of the method described above, and details of the system are not repeated herein.

The present application also provides a series resonance apparatus, including:

the proportion of the excitation inductor to the resonance inductor is adjustable;

a control circuit connected to the series resonant circuit for, when in operation, implementing any of the above-described method steps for extending the output hold time of the circuit.

For the introduction of the series resonant device provided in the present application, please refer to the embodiments of the above method, which is not described herein again.

It is further noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.