Starting method of dual-active series resonance circuit, controller, converter and system

Abstract

The invention discloses a starting method of a dual-active series resonance circuit, a controller, a converter and a system. The starting method of the dual-active series resonance circuit comprises the following steps: judging the type of a load actually accessed to an output side according to an actual output side voltage; if the type of the actually accessed load is a battery load, controlling the duty ratio and the frequency of the first wave transmission of the driving signal to be a target steady-state duty ratio and a target steady-state frequency respectively, and entering a phase shift angle closed-loop regulation stage; and if the type of the actually accessed load is a resistive load, controlling the duty ratio and the frequency of the first wave transmission of the driving signal to be a preset starting duty ratio and a preset starting frequency respectively, and controlling the driving signal to gradually increase the duty ratio and then gradually reduce the frequency until the phase shift angle closed-loop adjustment stage is entered. According to the starting method of the dual-active series resonance circuit provided by the embodiment of the invention, corresponding more stable soft start can be realized when different types of loads are connected to the dual-active series resonance circuit.

Description

Technical Field

[0001] The present application relates to the field of power supply circuits, and in particular to a startup method, a controller, a converter and a system for a dual active series resonant circuit. Background Art

[0002] The dual bridge series resonant converter (DBSRC) circuit has gradually become a popular solution for DC-DC transmission on the high-voltage side of on-board chargers due to its advantages such as high efficiency, wide gain range, high control freedom, and both resonance and soft switching characteristics.

[0003] Since the type of load connected to the dual active series resonant circuit is uncertain, it is difficult to provide a more complete soft start method at present. Summary of the invention

[0004] The present application provides a startup method, a controller, a converter and a system for a dual active series resonant circuit, which can achieve a corresponding more stable soft start when the dual active series resonant circuit is connected to different types of loads.

[0005] In a first aspect, an embodiment of the present application provides a method for starting a dual active series resonant circuit, wherein the dual active series resonant circuit includes a transformer, a primary full-bridge circuit connected to the primary winding of the transformer, and a secondary full-bridge circuit connected to the secondary winding of the transformer, wherein the output side of the dual active series resonant circuit can be selectively connected to a battery load or a resistive load, and at the same time of the startup process, the frequencies and duty cycles of the driving signals used to drive the primary full-bridge circuit and the secondary full-bridge circuit are the same, and the method for starting the dual active series resonant circuit includes: judging the type of load actually connected to the output side according to the actual output side voltage of the output side; if the type of load actually connected is a battery load, then The duty cycle and frequency of the first wave of the driving signal are controlled to be the target steady-state duty cycle and the target steady-state frequency, respectively, and enter the phase-shift angle closed-loop adjustment stage, wherein the target steady-state duty cycle is the duty cycle of the driving signal in steady-state operation, and the target steady-state frequency is the frequency of the driving signal in steady-state operation; if the load type actually connected is a resistive load, the duty cycle and frequency of the first wave of the driving signal are controlled to be the preset start-up duty cycle and the preset start-up frequency, respectively, and the driving signal is controlled to gradually increase the duty cycle and then gradually reduce the frequency until entering the phase-shift angle closed-loop adjustment stage, wherein the preset start-up duty cycle is less than the target steady-state duty cycle, and the preset start-up frequency is greater than the target steady-state frequency.

[0006] According to the aforementioned implementation manner of the first aspect of the present application, determining the type of load actually connected to the output side based on the actual output side voltage of the output side includes: if the actual output side voltage of the output side reaches a preset battery load threshold voltage, then the type of load actually connected to the output side is a battery load; otherwise, the type of load actually connected to the output side is a resistive load.

[0007] According to any of the aforementioned implementations of the first aspect of the present application, if the type of load actually connected is a battery load, the duty cycle and frequency of the first wave of the drive signal are controlled to be the target steady-state duty cycle and target steady-state frequency respectively, and the phase shift angle closed-loop adjustment stage is entered, and it also includes: controlling the initial phase shift angle parameters of the first wave of the drive signal to be: the outer phase shift angle is 0°, the primary side inner phase shift angle is 0°, and the secondary side inner phase shift angle is 0°.

[0008] According to any of the aforementioned implementations of the first aspect of the present application, if the type of load actually connected is a battery load, the duty cycle and frequency of the first wave of the drive signal are controlled to be the target steady-state duty cycle and target steady-state frequency respectively, and the phase shift angle closed-loop adjustment stage is entered, and it also includes: after entering the phase shift angle closed-loop adjustment stage, the external phase shift angle, the primary side internal phase shift angle and the secondary side internal phase shift angle are adjusted according to the currently sampled voltage and current information closed-loop control, so that the actual output power gradually increases until steady-state operation is achieved.

[0009] According to any of the aforementioned implementations of the first aspect of the present application, if the type of load actually connected is a resistive load, the duty cycle and frequency of the first wave of the drive signal are controlled to be a preset start-up duty cycle and a preset start-up frequency, respectively, and the drive signal is controlled to gradually increase the duty cycle and then gradually reduce the frequency until the phase shift angle closed-loop adjustment stage is entered, including: if the type of load actually connected is a resistive load, the duty cycle and frequency of the first wave of the drive signal are set to be a preset start-up duty cycle and a preset start-up frequency, respectively; the duty cycle of the drive signal is controlled to gradually increase according to a first step change rate until the duty cycle of the drive signal reaches the target steady-state duty cycle; the frequency of the drive signal is controlled to gradually decrease according to a second step change rate, so that the actual output side voltage gradually increases until the phase shift angle closed-loop adjustment stage is entered.

[0010] According to any of the aforementioned implementations of the first aspect of the present application, if the load type actually connected is a resistive load, the duty cycle and frequency of the first wave of the drive signal are set to a preset start-up duty cycle and a preset start-up frequency, respectively, and also includes: controlling the initial phase shift angle parameters of the first wave of the drive signal to be: an external phase shift angle of 0°, an internal phase shift angle of the primary side of 0°, and an internal phase shift angle of the secondary side of 0°.

[0011] According to any of the aforementioned embodiments of the first aspect of the present application, the frequency of the driving signal is controlled to gradually decrease according to a second step change rate, so that the actual output side voltage gradually increases until entering the phase shift angle closed-loop adjustment stage, including: controlling the frequency of the driving signal to gradually decrease according to the second step change rate, and controlling the external phase shift angle of the driving signal to gradually increase according to a third step change rate, so that the actual output side voltage gradually increases; continuously judging according to the current actual output side voltage and the frequency of the driving signal, and entering the phase shift angle closed-loop adjustment stage when the actual output side voltage reaches the target voltage and / or the frequency of the driving signal is reduced to the target steady-state frequency.

[0012] According to any of the aforementioned embodiments of the first aspect of the present application, the continuous judgment is performed based on the current actual output side voltage and the frequency of the drive signal, and the phase shift angle closed-loop adjustment stage is entered when the actual output side voltage reaches the target voltage and / or the frequency of the drive signal is reduced to the target steady-state frequency, including: if in the current judgment cycle, the actual output side voltage is lower than the target voltage, and the frequency of the drive signal is higher than the target steady-state frequency, then the frequency of the drive signal continues to be controlled to gradually decrease according to the second step change rate, and the external phase shift angle of the drive signal is controlled to gradually increase according to the third step change rate; if in the current judgment cycle, the actual output side voltage is lower than or has reached the target voltage, and the frequency of the drive signal has been reduced to the target steady-state frequency, then the duty cycle and frequency of the drive signal are maintained at the target steady-state duty cycle and the target steady-state frequency, respectively. The rate remains unchanged and enters the phase shift angle closed-loop adjustment stage. In the phase shift angle closed-loop adjustment stage, the outer phase shift angle, the primary side inner phase shift angle and the secondary side inner phase shift angle are adjusted in a closed-loop manner according to the currently sampled voltage and current information, so that the actual output power gradually increases until steady-state operation is achieved; if in the current judgment cycle, the actual output side voltage has reached the target voltage, and the frequency of the drive signal is higher than the target steady-state frequency, the duty cycle of the drive signal is maintained at the target steady-state duty cycle unchanged, and the frequency of the drive signal is controlled to gradually decrease according to the second step change rate until the frequency of the drive signal remains unchanged after decreasing to the target steady-state frequency, and enters the phase shift angle closed-loop adjustment stage. In the phase shift angle closed-loop adjustment stage, the outer phase shift angle, the primary side inner phase shift angle and the secondary side inner phase shift angle are adjusted in a closed-loop manner according to the currently sampled voltage and current information, so that the actual output power gradually increases until steady-state operation is achieved.

[0013] In a second aspect, an embodiment of the present application provides a controller for a dual active series resonant circuit, the controller comprising a memory and at least one processor, the memory being electrically connected to the at least one processor, the memory storing instructions, and the at least one processor calling the instructions in the memory so that the controller executes a startup method for the dual active series resonant circuit according to any of the foregoing embodiments of the present application.

[0014] In a third aspect, an embodiment of the present application provides a converter, including a dual active series resonant circuit and a controller of the dual active series resonant circuit of any of the foregoing embodiments of the present application.

[0015] In a fourth aspect, an embodiment of the present application provides a power supply system, comprising a converter according to any of the foregoing embodiments of the present application.

[0016] According to the startup method of the dual active series resonant circuit of the embodiment of the present application, the type of load actually connected to the output side is judged according to the actual output side voltage. When the type of load actually connected is a battery load or a resistive load, different soft start strategies are adopted respectively. The soft start strategies matching different load types are used to ensure that the dual active series resonant circuit and the corresponding system gradually achieve steady-state operation and increase the actual output power to the target value. When the type of load actually connected is a resistive load, the duty cycle is gradually increased and then the frequency is gradually reduced, so that the dual active series resonant circuit and the corresponding system can gradually enter the phase shift angle closed-loop adjustment stage more stably and reliably and gradually achieve steady-state operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0018] Figure 1 A circuit diagram of an embodiment of a dual active series resonant circuit of the present application;

[0019] Figure 2 A flowchart of an embodiment of a method for starting a dual active series resonant circuit of the present application;

[0020] Figure 3 This is a flow chart of a startup method for a dual active series resonant circuit in an embodiment of the present application, when the type of load actually connected is a resistive load;

[0021] Figure 4 A schematic diagram of timing changes when the duty cycle of a driving signal is gradually increased according to an embodiment of a startup method of a dual active series resonant circuit of the present application;

[0022] Figure 5 A schematic diagram of timing changes when the external shift phase angle of the control driving signal gradually increases in an embodiment of a startup method of a dual active series resonant circuit of the present application;

[0023] Figure 6 A schematic diagram of the timing changes of the actual output side voltage and the frequency of the driving signal under specific circumstances in an embodiment of the startup method of the dual active series resonant circuit of the present application;

[0024] Figure 7 This is a schematic diagram of the hardware structure of an embodiment of the controller of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0028] An embodiment of the present application provides a method for starting a dual bridge series resonant converter (DBSRC) circuit. Figure 1This is a circuit diagram of an embodiment of a dual active series resonant circuit of the present application. The dual active series resonant circuit includes a transformer 110, a primary full bridge circuit 120 connected to the primary winding Np of the transformer 110, and a secondary full bridge circuit 130 connected to the secondary winding Ns of the transformer 110. The output side V2 of the dual active series resonant circuit can be selectively connected to a battery (CV) load or a resistor (CR) load.

[0029] In this embodiment, the primary full-bridge circuit 120 is connected between the input side V1 of the dual active series resonant circuit and the primary winding Np, and the primary full-bridge circuit 120 includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, and a fourth switch tube Q4 connected as a full-bridge circuit. The secondary full-bridge circuit 130 includes a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7, and an eighth switch tube Q8 connected as a full-bridge circuit. In this embodiment, a resonant inductor L1 and a resonant capacitor C1 are also connected between the primary full-bridge circuit 120 and the primary winding Np. The input voltage of the input side V1 is converted into alternating current by the primary full-bridge circuit 120 and injected into the resonant cavity formed by the resonant inductor L1, the resonant capacitor C1, and the transformer 110, and reaches the secondary full-bridge circuit 130 after energy transfer in the resonant cavity, and transmits energy to the output side V2.

[0030] The first switch tube Q1 to the eighth switch tube Q8 are, for example, metal-oxide-semiconductor field-effect transistors (MOSFET).

[0031] The driving signal for driving the first switch tube Q1 to the eighth switch tube Q8 is, for example, a pulse width modulation (PWM) signal.

[0032] When the dual active series resonant circuit performs soft start, at the same time of the start process, the frequencies and duty ratios of the driving signals used to drive the primary full bridge circuit 120 and the secondary full bridge circuit 130 are the same. That is, at the same time of the start process, the frequencies and duty ratios of the driving signals used to drive the four switch tubes of the primary full bridge circuit 120 and the four switch tubes of the secondary full bridge circuit 130 are the same. The second switch tube Q2 always lags behind the first switch tube Q1 by half a cycle, the third switch tube Q3 always lags behind the fourth switch tube Q4 by half a cycle, the sixth switch tube Q6 always lags behind the fifth switch tube Q5 by half a cycle, and the seventh switch tube Q7 always lags behind the eighth switch tube Q8 by half a cycle.

[0033] Figure 2This is a flow chart of an embodiment of a method for starting a dual active series resonant circuit of the present application. The method for starting a dual active series resonant circuit includes step S110, step S120, and step S130.

[0034] In step S110, the type of load actually connected to the output side V2 is determined according to the actual output side voltage of the output side V2.

[0035] In some embodiments, the step S110 of determining the type of load actually connected to the output side V2 according to the actual output side voltage includes: if the actual output side voltage of the output side V2 reaches a preset battery load threshold voltage V2_flag, the type of load actually connected to the output side V2 is a battery load; otherwise, the type of load actually connected to the output side V2 is a resistive load. The battery load threshold voltage V2_flag is the theoretical minimum voltage of the battery load. The battery load threshold voltage V2_flag can be set or calibrated to a suitable value according to the voltage range of the actual battery load.

[0036] In step S120, if the load type actually connected is a battery load, the duty cycle and frequency of the first wave of the control driving signal are respectively controlled to be the target steady-state duty cycle Daim and the target steady-state frequency Faim, and the phase shift angle closed-loop adjustment stage is entered, wherein the target steady-state duty cycle Daim is the duty cycle of the driving signal in steady-state operation, and the target steady-state frequency Faim is the frequency of the driving signal in steady-state operation.

[0037] In this article, steady-state operation refers to a state in which the actual output side voltage and output current of the dual active series resonant circuit reach stable values ​​and the actual output power remains unchanged at the target power.

[0038] In some embodiments, step S120 further includes: controlling the initial phase shift angle parameters of the first wave of the driving signal to be: the outer phase shift angle α is 0°, the primary inner phase shift angle β1 is 0°, and the secondary inner phase shift angle β2 is 0°.

[0039] The period of the switch tube driving signal at the current moment is recorded as Ts.

[0040] The external phase shift angle α is the phase shift angle of the fifth switch tube Q5 of the secondary full-bridge circuit 130 relative to the first switch tube Q1 of the primary full-bridge circuit 120. If α≥0, the fifth switch tube Q5 starts to generate waves after a delay of α×Ts after the first switch tube Q1 starts to generate waves; if α<0, the first switch tube Q1 starts to generate waves after a delay of α×Ts after the fifth switch tube Q5 starts to generate waves.

[0041] The primary inner phase shift angle β1 is the phase shift angle of the fourth switch tube Q4 of the primary full-bridge circuit 120 relative to the first switch tube Q1 of the primary full-bridge circuit 120. β1≥0 means that the fourth switch tube Q4 starts to generate waves after a delay of β1×Ts after the first switch tube Q1 starts to generate waves; β1<0 means that the first switch tube Q1 starts to generate waves after a delay of β1×Ts after the fourth switch tube Q4 starts to generate waves.

[0042] The secondary side internal phase shift angle β2 is the phase shift angle of the eighth switch tube Q8 of the secondary side full bridge circuit 130 relative to the fifth switch tube Q5 of the secondary side full bridge circuit 130, β2≥0 means that the eighth switch tube Q8 starts to generate waves after a delay of β2×Ts after the fifth switch tube Q5 starts to generate waves; β2<0 means that the fifth switch tube Q5 starts to generate waves after a delay of β2×Ts after the eighth switch tube Q8 starts to generate waves.

[0043] In some embodiments, step S120 also includes: after entering the phase shift angle closed-loop adjustment stage, closed-loop control is performed to adjust the external phase shift angle α, the primary side internal phase shift angle β1, and the secondary side internal phase shift angle β2 according to the currently sampled voltage and current information, so that the actual output power gradually increases until steady-state operation.

[0044] In this embodiment, the currently sampled voltage and current information is the sampled actual input voltage of the input side V1 , the actual output side voltage of the output side V2 , and the output current of the output side V2 .

[0045] In step S130, if the type of load actually connected is a resistive load, the duty cycle and frequency of the first wave of the control driving signal are respectively the preset startup duty cycle Dmin and the preset startup frequency Fmax, and the control driving signal gradually increases the duty cycle and then gradually decreases the frequency until entering the phase shift angle closed-loop adjustment stage. The preset startup duty cycle Dmin is less than the target steady-state duty cycle Daim, and the preset startup frequency Fmax is greater than the target steady-state frequency Faim. In this embodiment, the preset startup duty cycle Dmin is the minimum duty cycle of the switch tube drive signal at the preset startup moment, and the preset startup frequency Fmax is the maximum frequency of the switch tube drive signal at the preset startup moment.

[0046] Figure 3 This is a flowchart of a startup method for a dual active series resonant circuit in an embodiment of the present application when the type of load actually connected is a resistive load. In some embodiments, step S130 further includes the following steps S131 to S137.

[0047] In step S131, if the load type actually connected is a resistive load, the duty cycle and frequency of the first wave of the driving signal are set to the preset starting duty cycle Dmin and the preset starting frequency Fmax, respectively. In some embodiments, this step also includes: controlling the initial phase shift angle parameters of the first wave of the driving signal to be: the outer phase shift angle α is 0°, the primary side inner phase shift angle β1 is 0°, and the secondary side inner phase shift angle β2 is 0°.

[0048] like Figure 4 In step S132, the duty cycle of the driving signal is gradually increased according to the first step length change rate ΔD0 / t1 until the duty cycle of the driving signal reaches the target steady-state duty cycle Daim. The first step length change rate ΔD0 / t1 refers to the step length D0 of the duty cycle change within the time t1, where t1 is the duration of the round control cycle. The duration of each round of control cycle is a preset value, and each round of control cycle includes multiple cycles Ts of the switch tube driving signal.

[0049] like Figure 4 , in an example scenario, Figure 4 The schematic diagram shows three sub-stages in the process of gradually increasing the duty cycle of the control driving signal: the first sub-stage P11, the second sub-stage P12, and the third sub-stage P13. The first sub-stage P11, the second sub-stage P12, and the third sub-stage P13 schematically show the signal timing of one cycle Ts of the switch tube driving signal.

[0050] In this embodiment, each switch tube is turned on at a high level as an example for explanation. In the first sub-stage P11, the duty cycle of the drive signal is, for example, a preset startup duty cycle Dmin. From the first sub-stage P11 to the second sub-stage P12, the proportion of the conduction segment in each (switching) cycle Ts increases, but still does not reach the target steady-state duty cycle Daim. From the second sub-stage P12 to the third sub-stage P13, the proportion of the conduction segment in each (switching) cycle Ts continues to increase, and finally reaches the target steady-state duty cycle Daim.

[0051] like Figure 5 After that, the frequency of the control driving signal is gradually reduced according to the second step change rate ΔF0 / t1, so that the actual output side voltage gradually increases until entering the phase shift angle closed-loop regulation stage. The second step change rate ΔF0 / t1 refers to the step size F0 of the frequency change of the switch tube within the time t1.

[0052] like Figure 5 , in an example scenario, Figure 5 The schematic diagram shows two sub-stages in the process of gradually reducing the frequency of the control driving signal: the fourth sub-stage P21 and the fifth sub-stage P22. The fourth sub-stage P21 and the fifth sub-stage P22 respectively schematically show the signal timing of two cycles Ts of the switch tube driving signal.

[0053] In this embodiment, the example of each switch tube being turned on at a high level is used for explanation. From the fourth sub-stage P21 to the fifth sub-stage P22, the frequency of the drive signal decreases, and therefore, the (switching) period of the drive signal is extended from the first period Ts1 of the fourth sub-stage P21 to the second period Ts2 of the fifth sub-stage P22. In this process, the duty cycle of the drive signal remains unchanged.

[0054] In this embodiment, the step of gradually decreasing the frequency of the control driving signal according to the second step change rate ΔF0 / t1 so that the actual output side voltage gradually increases until entering the phase shift angle closed-loop adjustment stage may further include the following steps:

[0055] In step S133, the frequency of the driving signal is controlled to gradually decrease according to the second step change rate ΔF0 / t1, and the external phase angle α of the driving signal is controlled to gradually increase according to the third step change rate Δα0 / t1, so that the actual output side voltage gradually increases. The third step change rate Δα0 / t1 means that the step size of the external phase angle α changing within the time t1 is α0. t1 is still the duration of this round of control cycle.

[0056] like Figure 5 In one example, in the fourth sub-stage P21, the external phase angle α is 0. After a period of time, from the fourth sub-stage P21 to the fifth sub-stage P22, except that the (switching) period of the driving signal is extended from the first period Ts1 of the fourth sub-stage P21 to the second period Ts2 of the fifth sub-stage P22, the external phase angle of the driving signal changes from 0 to αz.

[0057] In step S134, continuous judgment is performed based on the current actual output side voltage and the frequency of the drive signal. Through continuous judgment, when the actual output side voltage reaches the target voltage and / or the frequency of the drive signal decreases to the target steady-state frequency Faim, the phase shift angle closed-loop adjustment stage is entered.

[0058] In some embodiments, continuous judgment is performed based on the current actual output side voltage and the frequency of the driving signal, and when the actual output side voltage reaches the target voltage and / or the frequency of the driving signal decreases to the target steady-state frequency Faim, the phase shift angle closed-loop adjustment stage is entered, further including the following situations:

[0059] In step S135, if in the current judgment cycle, the actual output side voltage is lower than the target voltage V2_limit, and the frequency of the drive signal is higher than the target steady-state frequency Faim, the frequency of the drive signal continues to be controlled to gradually decrease according to the second step change rate ΔF0 / t1, and the external shift phase angle α of the drive signal is controlled to gradually increase according to the third step change rate Δα0 / t1.

[0060] The target voltage V2_limit is the output voltage that reaches the closed-loop mark point when a resistive load is connected.

[0061] In step S136, if in the current judgment cycle, the actual output side voltage is lower than or has reached the target voltage V2_limit, and the frequency of the drive signal has been reduced to the target steady-state frequency Faim, the duty cycle and frequency of the drive signal are maintained at the target steady-state duty cycle Daim and the target steady-state frequency Faim respectively, and the phase shift angle closed-loop adjustment stage is entered. In the phase shift angle closed-loop adjustment stage, the external phase shift angle α, the primary side internal phase shift angle β1, and the secondary side internal phase shift angle β2 are adjusted by closed-loop control according to the currently sampled voltage and current information, so that the actual output power is gradually increased until steady-state operation.

[0062] like Figure 6 In step S137, if in the current judgment cycle, the actual output side voltage has reached the target voltage V2_limit, and the frequency of the drive signal is higher than the target steady-state frequency Faim, the duty cycle of the drive signal is maintained at the target steady-state duty cycle Daim, and the frequency of the drive signal is controlled to gradually decrease according to the second step change rate ΔF0 / t1 until the frequency of the drive signal is reduced to the target steady-state frequency Faim and remains unchanged, and enters the phase shift angle closed-loop adjustment stage. In the phase shift angle closed-loop adjustment stage, the external phase shift angle α, the primary side internal phase shift angle β1, and the secondary side internal phase shift angle β2 are closed-loop controlled and adjusted according to the currently sampled voltage and current information, so that the actual output power is gradually increased until steady-state operation.

[0063] like Figure 6 , in an example scenario, Figure 6 The sixth sub-stage P31 and the seventh sub-stage P32 schematically show the signal timing of two cycles Ts of the switch tube drive signal, respectively.

[0064] In this embodiment, each switch tube is turned on at a high level as an example for explanation. From the sixth sub-stage P31 to the seventh sub-stage P32, the frequency of the drive signal decreases, so the (switching) period of the drive signal is extended from the third period Ts3 of the sixth sub-stage P31 to the fourth period Ts4 of the seventh sub-stage P32. In this process, the duty cycle of the drive signal remains unchanged. At the same time, due to entering the phase shift angle closed-loop adjustment stage, the external phase shift angle α, the primary side internal phase shift angle β1 and the secondary side internal phase shift angle β2 are adjusted. From the sixth sub-stage P31 to the seventh sub-stage P32, the external phase shift angle α changes from αx before adjustment to αy after adjustment. In the sixth sub-stage P31, the primary side internal phase shift angle β1 and the secondary side internal phase shift angle β2 are both 0. In the seventh sub-stage P32, the primary side internal phase shift angle β1 is adjusted to β11, and the secondary side internal phase shift angle β2 is adjusted to β21.

[0065] According to the startup method of the dual active series resonant circuit of the embodiment of the present application, the type of load actually connected to the output side V2 is judged according to the actual output side voltage. When the actually connected load type is a battery load or a resistive load, different soft start strategies are adopted respectively. The soft start strategies matching different load types are used to ensure that the dual active series resonant circuit and the corresponding system gradually achieve steady-state operation and increase the actual output power to the target value. When the actually connected load type is a resistive load, the duty cycle is gradually increased and then the frequency is gradually reduced, so that the dual active series resonant circuit and the corresponding system can gradually enter the phase shift angle closed-loop adjustment stage more stably and reliably and gradually achieve steady-state operation.

[0066] In some of the above embodiments, when the load type actually connected is a resistive load, the duty cycle and frequency of the first wave of the driving signal are set to the preset starting duty cycle Dmin and the preset starting frequency Fmax, respectively, and the initial phase shift angle parameters of the first wave of the driving signal are controlled as follows: the outer phase shift angle α is 0°, the primary side inner phase shift angle β1 is 0°, and the secondary side inner phase shift angle β2 is 0°. Thereafter, the duty cycle of the driving signal is controlled to gradually increase according to the first step length change rate ΔD0 / t1 until the duty cycle of the driving signal reaches the target steady-state duty cycle Daim. Afterwards, the frequency of the control drive signal is gradually reduced according to the second step change rate ΔF0 / t1. At the same time, the change of the external phase shift angle α is introduced, and the external phase shift angle α of the control drive signal is gradually increased according to the third step change rate Δα0 / t1, so that the actual output side voltage gradually increases, which can further accelerate the voltage difference between the input side and the output side V2, and help the actual output side V2 to increase faster. In this way, when entering the phase shift angle closed-loop adjustment stage, the control stability when the internal phase shift angle change is introduced can be improved, and the stability and reliability of the soft start and operation of the dual active series resonant circuit and the corresponding system can be further improved.

[0067] The embodiment of the present application also provides a controller for a dual active series resonant circuit. Figure 7 Schematic diagram of the hardware structure of an embodiment of the controller of the present application. The controller includes a memory 710 and at least one processor 720, and the memory 710 is electrically connected to the at least one processor 720. Instructions are stored in the memory 710, and at least one processor 720 calls the instructions in the memory 710, so that the controller executes the startup method of the dual active series resonant circuit according to any of the aforementioned embodiments of the present application.

[0068] The dual active series resonant circuit includes a transformer 110, a primary full bridge circuit 120 connected to the primary winding Np of the transformer 110, and a secondary full bridge circuit 130 connected to the secondary winding Ns of the transformer 110. The output side V2 of the dual active series resonant circuit can be selectively connected to a battery (CV) load or a resistor (CR) load. When the dual active series resonant circuit performs soft start, at the same time of the start process, the frequencies and duty cycles of the driving signals for driving the four switch tubes of the primary full bridge circuit 120 and the four switch tubes of the secondary full bridge circuit 130 are the same.

[0069] The starting method of the dual active series resonant circuit includes: judging the type of load actually connected to the output side according to the actual output side voltage of the output side; if the type of load actually connected is a battery load, then controlling the duty cycle and frequency of the first wave of the driving signal to be the target steady-state duty cycle and the target steady-state frequency respectively, and entering the phase shift angle closed-loop adjustment stage, wherein the target steady-state duty cycle is the duty cycle of the driving signal in steady-state operation, and the target steady-state frequency is the frequency of the driving signal in steady-state operation; if the type of load actually connected is a resistive load, then controlling the duty cycle and frequency of the first wave of the driving signal to be the preset starting duty cycle and the preset starting frequency respectively, and controlling the driving signal to gradually increase the duty cycle first and then gradually reduce the frequency until entering the phase shift angle closed-loop adjustment stage, wherein the preset starting duty cycle is less than the target steady-state duty cycle, and the starting frequency is greater than the target steady-state frequency.

[0070] Specifically, the processor 720 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0071] The memory 710 may include a large capacity memory 710 for data or instructions. By way of example and not limitation, the memory 710 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 710 may include a removable or non-removable (or fixed) medium. Where appropriate, the memory 710 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 710 is a non-volatile solid-state memory. In a specific embodiment, the memory 710 includes a read-only memory (ROM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or a flash memory, or a combination of two or more of these.

[0072] In one example, the control device may further include a communication interface 730 and a bus 740. The processor 720, the memory 710, and the communication interface 730 are connected via the bus 740 and communicate with each other.

[0073] The communication interface 730 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0074] Bus 740 includes hardware, software or both, and the parts of online data flow billing equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-end bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory 710 bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 740 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0075] In addition, in combination with the startup method of the dual active series resonant circuit in the above embodiment, the embodiment of the present application can provide a power supply system to implement. The power supply system stores instructions, and when the instructions are executed by the processor, the startup method of the dual active series resonant circuit in any of the above embodiments is implemented.

[0076] The embodiment of the present application also provides a converter, which includes a dual active series resonant circuit and a controller of the dual active series resonant circuit of any of the above embodiments. The controller can implement a startup method of the dual active series resonant circuit of any of the above embodiments.

[0077] An embodiment of the present application also provides a power supply system, which includes a converter according to any of the aforementioned embodiments.

[0078] According to the converter and power supply system of the embodiment of the present application, when controlling the soft start of the dual active series resonant circuit, the type of load actually connected to the output side can be judged according to the actual output side voltage. When the type of load actually connected is a battery load or a resistive load, different soft start strategies are adopted respectively. The soft start strategies matching different load types are used to ensure that the dual active series resonant circuit and the corresponding system gradually achieve steady-state operation and increase the actual output power to the target value. When the type of load actually connected is a resistive load, the duty cycle is gradually increased and then the frequency is gradually reduced, so that the dual active series resonant circuit and the corresponding system can gradually enter the phase shift angle closed-loop adjustment stage more stably and reliably and gradually achieve steady-state operation.

[0079] The present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0080] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0081] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0082] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for starting a dual active series resonant circuit, characterized in that: The dual active series resonant circuit comprises a transformer, a primary full-bridge circuit connected to the primary winding of the transformer, and a secondary full-bridge circuit connected to the secondary winding of the transformer. The output side of the dual active series resonant circuit can be selectively connected to a battery load or a resistance load. At the same time of the startup process, the frequencies and duty cycles of the driving signals for driving the primary full-bridge circuit and the secondary full-bridge circuit are the same. The starting method of the dual active series resonant circuit comprises: Determining the type of load actually connected to the output side according to the actual output side voltage of the output side; If the type of load actually connected is a battery load, the duty cycle and frequency of the first wave of the driving signal are controlled to be the target steady-state duty cycle and the target steady-state frequency respectively, and the phase shift angle closed-loop adjustment stage is entered, wherein the target steady-state duty cycle is the duty cycle of the driving signal in steady-state operation, and the target steady-state frequency is the frequency of the driving signal in steady-state operation; If the load type actually connected is a resistive load, the duty cycle and frequency of the first wave of the driving signal are controlled to be the preset starting duty cycle and the preset starting frequency respectively, and the driving signal is controlled to gradually increase the duty cycle and then gradually reduce the frequency until entering the phase shift angle closed-loop adjustment stage, wherein the preset starting duty cycle is less than the target steady-state duty cycle, and the preset starting frequency is greater than the target steady-state frequency.

2. The startup method of the dual active series resonant circuit according to claim 1, characterized in that: The determining the type of load actually connected to the output side according to the actual output side voltage of the output side includes: If the actual output side voltage of the output side reaches the preset battery load threshold voltage, the type of load actually connected to the output side is a battery load; otherwise, the type of load actually connected to the output side is a resistance load.

3. The startup method of the dual active series resonant circuit according to claim 1, characterized in that: If the type of load actually connected is a battery load, the duty cycle and frequency of the first wave of the driving signal are controlled to be the target steady-state duty cycle and the target steady-state frequency respectively, and the phase shift angle closed-loop adjustment stage is entered, which also includes: The initial phase shift angle parameters for controlling the first wave of the driving signal are: the outer phase shift angle is 0°, the inner phase shift angle of the primary side is 0°, and the inner phase shift angle of the secondary side is 0°.

4. The startup method of the dual active series resonant circuit according to claim 3, characterized in that: If the type of load actually connected is a battery load, the duty cycle and frequency of the first wave of the driving signal are controlled to be the target steady-state duty cycle and the target steady-state frequency respectively, and the phase shift angle closed-loop adjustment stage is entered, which also includes: After entering the phase shift angle closed-loop adjustment stage, the external phase shift angle, the primary side internal phase shift angle and the secondary side internal phase shift angle are adjusted by closed-loop control according to the currently sampled voltage and current information, so that the actual output power is gradually increased until steady-state operation.

5. The startup method of the dual active series resonant circuit according to claim 1, characterized in that: If the load type actually connected is a resistive load, the duty cycle and frequency of the first wave of the driving signal are controlled to be respectively the preset starting duty cycle and the preset starting frequency, and the driving signal is controlled to gradually increase the duty cycle and then gradually reduce the frequency until entering the phase shift angle closed-loop adjustment stage, including: If the type of load actually connected is a resistive load, the duty cycle and frequency of the first wave of the driving signal are set to the preset starting duty cycle and the preset starting frequency respectively; Controlling the duty cycle of the driving signal to gradually increase according to the first step length change rate until the duty cycle of the driving signal reaches the target steady-state duty cycle; The frequency of the driving signal is controlled to gradually decrease according to the second step change rate, so that the actual output side voltage gradually increases until entering the phase shift angle closed-loop regulation stage.

6. The startup method of the dual active series resonant circuit according to claim 5, characterized in that: If the type of load actually connected is a resistive load, the duty cycle and frequency of the first wave of the driving signal are set to a preset starting duty cycle and a preset starting frequency respectively, and further comprising: The initial phase shift angle parameters for controlling the first wave of the driving signal are: the outer phase shift angle is 0°, the inner phase shift angle of the primary side is 0°, and the inner phase shift angle of the secondary side is 0°.

7. The startup method of the dual active series resonant circuit according to claim 6, characterized in that: The step of controlling the frequency of the driving signal to gradually decrease according to the second step change rate so that the actual output side voltage gradually increases until entering the phase shift angle closed-loop adjustment stage comprises: Controlling the frequency of the driving signal to gradually decrease according to a second step change rate, and controlling the outer phase angle of the driving signal to gradually increase according to a third step change rate, so that the actual output side voltage gradually increases; Continuous judgment is performed based on the current actual output side voltage and the frequency of the drive signal, and the phase shift angle closed-loop adjustment stage is entered when the actual output side voltage reaches the target voltage and / or the frequency of the drive signal decreases to the target steady-state frequency.

8. The startup method of the dual active series resonant circuit according to claim 7, characterized in that: The continuous judgment is performed based on the current actual output side voltage and the frequency of the drive signal, and when the actual output side voltage reaches the target voltage and / or the frequency of the drive signal decreases to the target steady-state frequency, the phase shift angle closed-loop adjustment stage is entered, including: If in the current judgment cycle, the actual output side voltage is lower than the target voltage, and the frequency of the drive signal is higher than the target steady-state frequency, then continue to control the frequency of the drive signal to gradually decrease according to the second step change rate, and control the external shift phase angle of the drive signal to gradually increase according to the third step change rate; If in the current judgment cycle, the actual output side voltage is lower than or has reached the target voltage, and the frequency of the drive signal has been reduced to the target steady-state frequency, the duty cycle and frequency of the drive signal are maintained at the target steady-state duty cycle and the target steady-state frequency respectively and the phase shift angle closed-loop adjustment stage is entered. In the phase shift angle closed-loop adjustment stage, the outer phase shift angle, the primary side inner phase shift angle and the secondary side inner phase shift angle are adjusted by closed-loop control according to the currently sampled voltage and current information, so that the actual output power is gradually increased until steady-state operation is achieved; If in the current judgment cycle, the actual output side voltage has reached the target voltage, and the frequency of the drive signal is higher than the target steady-state frequency, the duty cycle of the drive signal is maintained at the target steady-state duty cycle, and the frequency of the drive signal is controlled to gradually decrease according to the second step change rate until the frequency of the drive signal is reduced to the target steady-state frequency and remains unchanged, and enters the phase shift angle closed-loop adjustment stage. In the phase shift angle closed-loop adjustment stage, the outer phase shift angle, the primary side inner phase shift angle and the secondary side inner phase shift angle are adjusted by closed-loop control according to the currently sampled voltage and current information, so that the actual output power is gradually increased until steady-state operation is achieved.

9. A controller for a dual active series resonant circuit, characterized in that: The controller includes a memory and at least one processor, the memory is electrically connected to the at least one processor, and instructions are stored in the memory. The at least one processor calls the instructions in the memory, so that the controller executes the startup method of the dual active series resonant circuit according to any one of claims 1 to 8.

10. A converter, characterized in that: The invention comprises a dual active series resonant circuit and a controller of the dual active series resonant circuit as claimed in claim 9.

11. A power supply system, characterized in that: Comprising a converter as claimed in claim 10.

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