Current control method of resonance circuit, resonance circuit and energy storage inversion equipment

Abstract

The invention discloses a current control method of a resonant circuit, the resonant circuit and energy storage inversion equipment, the resonant circuit comprises a primary circuit, a secondary circuit, a resonant inductor and a resonant capacitor, the primary circuit is connected to the secondary circuit through the resonant inductor, the resonant capacitor is connected in parallel with the secondary circuit, the primary circuit is used for connecting a DC side, and the secondary circuit is used for connecting a DC side. The secondary circuit is used for connecting an AC side; the current control method comprises the following steps: acquiring an inner phase shift angle of a primary side circuit and an outer phase shift angle between the primary side circuit and a secondary side circuit; obtaining a direct-current voltage of a direct-current side and an alternating-current voltage of an alternating-current side; obtaining a target current effective value according to the internal phase shift angle, the external phase shift angle, the DC voltage, the AC voltage and a preset current effective value algorithm; and adjusting working parameters of the primary circuit and the secondary circuit according to the target current effective value. The conduction loss of the resonance circuit can be reduced, and the working efficiency of the resonance circuit is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power conversion circuits, and in particular to a current control method of a resonant circuit, a resonant circuit, and an energy storage inverter device. Background Art

[0002] At present, resonant circuits are widely used in various devices with power conversion functions, such as energy storage inverter devices. In the existing resonant circuit, the secondary voltage is a time-varying quantity when working, which causes the current in the resonant inductor to also be a time-varying quantity. However, the prior art lacks means to optimize the current in the resonant inductor, which leads to high conduction loss of each switch tube in the resonant circuit, thereby affecting the working efficiency of the resonant circuit. Summary of the invention

[0003] In view of this, the present application provides a current control method of a resonant circuit, a resonant circuit and an energy storage inverter device, which are used to reduce the conduction loss of the resonant circuit and improve the working efficiency of the resonant circuit. The technical solution of the present application is as follows:

[0004] In a first aspect, the present application provides a current control method for a resonant circuit, wherein the resonant circuit comprises a primary circuit, a secondary circuit, a resonant inductor and a resonant capacitor, wherein the primary circuit is connected to the secondary circuit via the resonant inductor, the resonant capacitor is connected in parallel with the secondary circuit, the primary circuit is used to connect to a DC side, and the secondary circuit is used to connect to an AC side; the current control method comprises: obtaining an inner phase shift angle of the primary circuit and an outer phase shift angle between the primary circuit and the secondary circuit; obtaining a DC voltage on the DC side and an AC voltage on the AC side; obtaining a target current effective value according to the inner phase shift angle, the outer phase shift angle, the DC voltage, the AC voltage and a preset current effective value algorithm; and adjusting the operating parameters of the primary circuit and the secondary circuit according to the target current effective value.

[0005] In one embodiment of the present application, the target current effective value is obtained according to the inner phase shift angle, the outer phase shift angle, the DC voltage, the AC voltage and a preset current effective value algorithm, including: obtaining the primary voltage according to the inner phase shift angle and the DC voltage, and obtaining the secondary voltage according to the outer phase shift angle and the AC voltage; calculating the resonant current amplitude of the resonant inductor according to the primary voltage and the secondary voltage; obtaining the target current effective value according to the resonant current amplitude and a preset soft switching constraint.

[0006] In one embodiment of the present application, obtaining the primary voltage according to the inner phase shift angle and the DC voltage, and obtaining the secondary voltage according to the outer phase shift angle and the AC voltage include: obtaining an expression of the primary voltage based on a fundamental wave analysis method using the inner phase shift angle and the DC voltage; obtaining an expression of the secondary voltage based on a fundamental wave analysis method using the outer phase shift angle and the AC voltage.

[0007] In one embodiment of the present application, obtaining the resonant current amplitude of the resonant inductor according to the primary voltage and the secondary voltage includes: obtaining a resonant current expression according to an expression of the primary voltage, an expression of the secondary voltage and the resonant impedance, wherein the resonant impedance is obtained based on the resonant inductor and the resonant capacitor; obtaining a current amplitude expression according to the resonant current expression, which is the resonant current amplitude.

[0008] In one embodiment of the present application, the target current effective value is obtained based on the resonant current amplitude and the preset soft switching constraint conditions, including: under the soft switching constraint conditions, obtaining the corresponding value of the current amplitude expression based on the target gain ratio as the target current effective value, and the target gain ratio is based on the voltage gain ratio of the primary voltage to the secondary voltage.

[0009] In one embodiment of the present application, obtaining the target current effective value based on the resonant current amplitude and preset soft switching constraints includes: obtaining the minimum value of the current amplitude expression under the soft switching constraints as the target current effective value.

[0010] The second aspect of the present application provides a resonant circuit, including a primary circuit, a secondary circuit, a transformer, a resonant inductor, a resonant capacitor and a controller, wherein the primary circuit is connected to the secondary circuit through the transformer and the resonant inductor, the resonant inductor is connected in series with the secondary circuit, the resonant capacitor is connected in parallel with the secondary circuit, the primary circuit is used to connect to the DC side, and the secondary circuit is used to connect to the AC side; the controller is connected to the primary circuit and the secondary circuit, and the controller is used to obtain a target current effective value according to an internal phase shift angle of the primary circuit, an external phase shift angle between the primary circuit and the secondary circuit, a DC voltage on the DC side, an AC voltage on the AC side and a preset current effective value algorithm, and adjust the operating parameters of the primary circuit and the secondary circuit according to the target current effective value.

[0011] In one embodiment of the present application, the primary circuit is a full-bridge circuit, including a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a primary inductor and a primary capacitor; the first end of the first switch tube is used to connect to the positive electrode of the DC side, and the second end of the first switch tube is connected to the first end of the second switch tube; the second end of the second switch tube is used to connect to the negative electrode of the DC side; the first end of the third switch tube is connected to the first end of the first switch tube, and the second end of the third switch tube is connected to the first end of the fourth switch tube; the second end of the fourth switch tube is connected to the second end of the second switch tube; the first input end of the transformer is connected to the second end of the first switch tube, and the second input end of the transformer is connected to the second end of the third switch tube; the primary inductor is connected in parallel with the input end of the transformer; and the primary capacitor is connected in parallel with the DC side.

[0012] In one embodiment of the present application, the secondary circuit is a half-bridge circuit, including a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube, and the resonant capacitor includes a first capacitor and a second capacitor; the fifth switch tube, the sixth switch tube, the seventh switch tube, the eighth switch tube, the second capacitor and the first capacitor are connected in series in sequence; the first output end of the transformer is connected between the sixth switch tube and the seventh switch tube through the resonant inductor, and the second output end of the transformer is connected between the first capacitor and the second capacitor.

[0013] A third aspect of the present application provides an energy storage inverter device, comprising the resonant circuit.

[0014] It can be understood that the present application obtains the inner phase shift angle of the primary circuit in the resonant circuit, the outer phase shift angle of the secondary circuit, the DC voltage on the DC side, and the AC voltage on the AC side to calculate the target current effective value with a smaller resonant inductance in the resonant circuit, and then adjusts the actual inductance current of the resonant inductor according to the target current effective value, thereby reducing the conduction loss of each switching tube and improving the working efficiency of the resonant circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an equivalent schematic block diagram of a resonant circuit provided in an embodiment of the present application.

[0016] Figure 2 It is a flow chart of a current control method of a resonant circuit provided in an embodiment of the present application.

[0017] Figure 3 It is a flow chart of obtaining a target current effective value provided by an embodiment of the present application.

[0018] Figure 4It is a schematic diagram of a flow chart for obtaining a primary voltage and a secondary voltage provided in an embodiment of the present application.

[0019] Figure 5 It is a schematic diagram of a flow chart of obtaining the resonant current amplitude provided in an embodiment of the present application.

[0020] Figure 6 It is a schematic block diagram of a resonant circuit provided in an embodiment of the present application.

[0021] Figure 7 It is a circuit diagram of a resonant circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] It should be noted that in the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0023] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0024] At present, resonant circuits are widely used in various devices with power conversion functions, such as energy storage inverter devices. In the existing resonant circuit, the secondary voltage is a time-varying quantity when working, which causes the current in the resonant inductor to also be a time-varying quantity. However, the prior art lacks means to optimize the current in the resonant inductor, which leads to high conduction loss of each switch tube in the resonant circuit, thereby affecting the working efficiency of the resonant circuit.

[0025] The embodiments of the present application provide a resonant circuit and a current control method thereof, which are used to reduce the conduction loss of each switch tube and improve the working efficiency of the resonant circuit.

[0026] Please refer to Figure 1 , Figure 1 An equivalent schematic block diagram of a resonant circuit provided in an embodiment of the present application, wherein the resonant circuit 100 includes a primary circuit 110 , a secondary circuit 120 , a resonant inductor 130 and a resonant capacitor 140 .

[0027] In the embodiment of the present application, the primary circuit 110 is connected to the secondary circuit 120 via the resonant inductor 130, the resonant capacitor 140 is connected in parallel with the secondary circuit 120, the primary circuit 110 is used to connect the DC side, and the secondary circuit 120 is used to connect the AC side.

[0028] It can be understood that when the resonant circuit 100 is working, the DC voltage on the DC side is received through the primary circuit 110, and the DC voltage can be converted into a primary AC voltage and then transmitted to the secondary circuit 120 through the resonant inductor 130, and then the secondary circuit 120 adjusts the waveform of the primary AC voltage, and finally outputs the AC voltage to the AC side. Alternatively, the AC voltage on the AC side is received through the secondary circuit 120, and the AC voltage can be converted into a primary DC voltage and then transmitted to the primary circuit 110 through the resonant inductor 130, and then the primary circuit 110 adjusts the waveform of the primary DC voltage, and finally outputs the DC voltage to the DC side.

[0029] Next, combine Figure 1 A current control method for a resonant circuit provided in an embodiment of the present application is described. Please refer to Figure 2 , specifically including the following steps:

[0030] Step S21: obtaining an inner phase shift angle of the primary circuit and an outer phase shift angle between the primary circuit and the secondary circuit.

[0031] In the embodiment of the present application, the resonant circuit can also be connected to a controller, which controls it to work and executes the various steps in the present embodiment. For example, in an energy storage inverter device provided with a resonant circuit, the primary circuit and the secondary circuit of the resonant circuit can be connected to the main controller of the energy storage inverter device, and the main controller of the energy storage inverter device controls the switching parameters of the primary circuit and the secondary circuit, thereby controlling them to work, and the main controller also executes the various steps in the present embodiment.

[0032] Among them, after controlling the resonant circuit to work, the controller can define a variable of the inner phase shift angle of the primary circuit and a variable of the outer phase shift angle between the primary circuit and the secondary circuit, so that after subsequently calculating the target current effective value of the resonant circuit, the corresponding inner phase shift angle and the corresponding outer phase shift angle can be obtained according to the target current effective value as working parameters to adjust the resonant circuit.

[0033] Step S22: obtaining the DC voltage on the DC side and the AC voltage on the AC side.

[0034] In the implementation of the present application, the controller may also be connected to the DC side and the AC side of the resonant circuit to obtain the DC voltage on the DC side and the AC voltage on the AC side. In some embodiments, a DC voltage sampling circuit may be provided on the DC side, and an AC voltage sampling circuit may be provided on the AC side, the DC voltage sampling circuit is used to collect the DC voltage on the DC side and transmit it to the controller, and the AC voltage sampling circuit is used to collect the AC voltage on the AC side and transmit it to the controller.

[0035] Step S23: Obtain a target current effective value according to the inner phase shift angle, the outer phase shift angle, the DC voltage, the AC voltage and a preset current effective value algorithm.

[0036] In the embodiment of the present application, after obtaining the current inner phase shift angle, outer phase shift angle, DC voltage on the DC side, and AC voltage on the AC side of the resonant circuit, the controller can use a preset current effective value algorithm to obtain the target current effective value of the resonant inductor. It can be understood that the current effective value of the resonant inductor is positively correlated with the conduction loss of each switch tube in the resonant circuit. Therefore, under the soft switching condition constraint of the resonant circuit, a smaller target current effective value of the resonant inductor is obtained, and the actual inductance current of the resonant inductor is adjusted according to the target current effective value, which can reduce the conduction loss of each switch tube, thereby improving the working efficiency of the resonant circuit.

[0037] Step S24: adjusting the operating parameters of the primary circuit and the secondary circuit according to the target current effective value.

[0038] In an embodiment of the present application, after the controller obtains the target current effective value of the resonant inductor according to a preset current effective value algorithm, it can adjust the operating parameters of the primary circuit and the secondary circuit according to the target current effective value, so that the current value of the resonant inductor gradually approaches the target current effective value, thereby reducing the conduction loss of each switching tube, thereby improving the working efficiency of the resonant circuit.

[0039] In some embodiments, the controller can adjust the duty cycle and frequency of each switch tube in the primary circuit and the secondary circuit when they are turned on and off, thereby adjusting the current value of the resonant inductor. For example, when the controller outputs a PWM signal to each switch tube in the primary circuit and the secondary circuit for control, the controller can adjust the duty cycle and frequency of the PWM signal. When adjusting the duty cycle of the primary circuit and the secondary circuit, the controller can calculate the corresponding inner phase shift angle and outer phase shift angle according to the above target current effective value, and then control the above duty cycle according to the inner phase shift angle and the outer phase shift angle.

[0040] It can be understood that the present application obtains the inner phase shift angle of the primary circuit in the resonant circuit, the outer phase shift angle of the secondary circuit, the DC voltage on the DC side, and the AC voltage on the AC side to calculate the target current effective value with a smaller resonant inductance in the resonant circuit, and then adjusts the actual inductance current of the resonant inductor according to the target current effective value, thereby reducing the conduction loss of each switching tube and improving the working efficiency of the resonant circuit.

[0041] In some embodiments, please refer to Figure 3 The above step S23 of obtaining the target current effective value may further include the following steps:

[0042] Step S31: obtaining a primary voltage according to an inner phase shift angle and a DC voltage, and obtaining a secondary voltage according to an outer phase shift angle and an AC voltage.

[0043] It can be understood that after obtaining the inner phase shift angle and the DC voltage, the controller of the resonant circuit can calculate the primary voltage of the primary circuit based on the inner phase shift angle and the DC voltage, and after obtaining the outer phase shift angle and the AC voltage, the controller can calculate the secondary voltage of the secondary circuit based on the outer phase shift angle and the AC voltage.

[0044] Step S32: Calculate the resonant current amplitude of the resonant inductor according to the primary voltage and the secondary voltage.

[0045] It can be understood that both the primary voltage and the secondary voltage are AC voltages. In some embodiments, after calculating and obtaining the primary voltage and the secondary voltage, the controller can further obtain the resonant current amplitude of the resonant inductor according to the primary voltage and the secondary voltage. For example, the controller can calculate the resonant voltage of the resonant inductor according to the primary voltage and the secondary voltage, obtain the resonant current according to the resonant voltage and the impedance of the resonant inductor, and finally obtain the above-mentioned resonant current amplitude.

[0046] Step S33: Obtaining a target current effective value according to the resonant current amplitude and preset soft switching constraints.

[0047] In the embodiment of the present invention, after obtaining the resonant current amplitude, the controller can calculate and obtain the above-mentioned target current effective value according to the resonant current amplitude and the preset soft switching constraint condition.

[0048] In some embodiments, please refer to Figure 4 The above step S31 of obtaining the primary voltage and the secondary voltage may further include the following steps:

[0049] Step S41: using the internal phase shift angle and the DC voltage to obtain an expression for the primary voltage based on the fundamental wave analysis method.

[0050] In the embodiment of the present application, the expression of the primary voltage constructed based on the fundamental wave analysis method can be:

[0051]

[0052] In the formula, v p is the primary voltage, V dc is the DC voltage on the DC side, n is the turns ratio of the transformer between the primary voltage and the transformed voltage, and D1 is the internal phase shift angle.

[0053] Step S42: using the external phase shift angle and the AC voltage to obtain an expression for the secondary voltage based on the fundamental wave analysis method.

[0054] In the embodiment of the present application, the expression of the secondary voltage constructed based on the fundamental wave analysis method can be:

[0055]

[0056] In the formula, v s is the secondary voltage, U g is the AC voltage on the AC side, and D2 is the external shift phase angle.

[0057] In some embodiments, please refer to Figure 5 The above step S32 of obtaining the resonant current amplitude may further include the following steps:

[0058] Step S51: obtaining a resonant current expression according to an expression of the primary voltage, an expression of the secondary voltage and the resonant impedance, wherein the resonant impedance is obtained based on the resonant inductance and the resonant capacitance.

[0059] In the embodiment of the present application, the resonant current expression based on the fundamental wave analysis method can be:

[0060]

[0061] Where i is the resonant current, X eq is the above-mentioned resonant impedance.

[0062] Step S52: Obtain a current amplitude expression according to the resonant current expression, which is the resonant current amplitude.

[0063] In the embodiment of the present application, the above formula can be written The current amplitude expression can be obtained as That is the above-mentioned resonant current amplitude.

[0064] In some embodiments, the target current effective value is obtained based on the resonant current amplitude and preset soft switching constraints, including: under the soft switching constraints, obtaining the current amplitude expression based on the corresponding value of the target gain ratio as the target current effective value, and the target gain ratio is based on the voltage gain ratio of the primary voltage to the secondary voltage.

[0065] In the embodiment of the present application, according to the resonant current expression The part of the resonant current related to the inner phase shift angle and the outer phase shift angle can be obtained, that is, the part related to the control amount is obtained as: Then we know that the soft switching condition is

[0066] It can be understood that the resonant current amplitude is The part of the resonant current amplitude related to the inner phase shift angle and the outer phase shift angle is obtained, that is, the part related to the control amount is obtained as follows: Where m is the voltage gain ratio of the primary voltage to the secondary voltage.

[0067] If the soft switching constraint is met The resonant current amplitude corresponding to the minimum G value can be obtained, and A is the target current effective value.

[0068] In some embodiments, the above-mentioned obtaining the target current effective value according to the resonant current amplitude and the preset soft switching constraint condition may also include: obtaining the minimum value of the current amplitude expression under the soft switching constraint condition as the target current effective value.

[0069] In the embodiment of the present application, it is also possible to directly obtain The resonant current amplitude corresponding to the minimum value is A, which is the target current effective value.

[0070] Please refer to Figure 6 , Figure 6 A schematic block diagram of a resonant circuit provided in an embodiment of the present application, wherein the resonant circuit 600 includes: a primary circuit 610, a secondary circuit 620, a transformer 630, a resonant inductor 640, a resonant capacitor 650 and a controller 660.

[0071] In the embodiment of the present application, the primary circuit 610 is connected to the secondary circuit 620 through the transformer 630 and the resonant inductor 640, the resonant inductor 640 is connected in series with the secondary circuit 620, the resonant capacitor 650 is connected in parallel with the secondary circuit 620, the primary circuit 610 is used to connect the DC side, and the secondary circuit 620 is used to connect the AC side;

[0072] The controller 660 is connected to the primary circuit 610 and the secondary circuit 620. The controller 660 is used to obtain a target current effective value based on the internal phase shift angle of the primary circuit 610, the external phase shift angle between the primary circuit 610 and the secondary circuit 620, the DC voltage on the DC side, the AC voltage on the AC side, and a preset current effective value algorithm, and adjust the operating parameters of the primary circuit 610 and the secondary circuit 620 according to the target current effective value.

[0073] In some embodiments, the controller 660 is also used to: obtain the primary voltage according to the internal phase shift angle and the DC voltage, obtain the secondary voltage according to the external phase shift angle and the AC voltage, calculate the resonant current amplitude of the resonant inductor according to the primary voltage and the secondary voltage, and obtain the target current effective value according to the resonant current amplitude and preset soft switching constraints.

[0074] In some embodiments, the controller 660 is further used to: obtain an expression of the primary voltage based on the fundamental wave analysis method using the inner phase shift angle and the DC voltage, and obtain an expression of the secondary voltage based on the fundamental wave analysis method using the outer phase shift angle and the AC voltage.

[0075] In some embodiments, the controller 660 is also used to: obtain a resonant current expression based on an expression of the primary voltage, an expression of the secondary voltage, and the resonant impedance, wherein the resonant impedance is obtained based on the resonant inductance and the resonant capacitance, and obtain a current amplitude expression based on the resonant current expression, which is the resonant current amplitude.

[0076] In some embodiments, the controller 660 is further used to: under soft switching constraints, obtain the corresponding value of the current amplitude expression of the target gain ratio as the target current effective value, and the target gain ratio is based on the voltage gain ratio of the primary voltage to the secondary voltage.

[0077] Please refer to Figure 7 , Figure 7 A circuit diagram of a resonant circuit 600 provided in an embodiment of the present application, wherein the primary circuit 610 is a full-bridge circuit, including a first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a primary inductor Lm and a primary capacitor Cdc.

[0078] In the embodiment of the present application, the first end of the first switch tube S1 is used to connect to the positive electrode of the DC side Vdc, and the second end of the first switch tube S1 is connected to the first end of the second switch tube S2; the second end of the second switch tube S2 is used to connect to the negative electrode of the DC side Vdc; the first end of the third switch tube S3 is connected to the first end of the first switch tube S1, and the second end of the third switch tube is connected to the first end of the fourth switch tube S4; the second end of the fourth switch tube S4 is connected to the second end of the second switch tube S2.

[0079] The first input end of the transformer 630 is connected to the second end of the first switch tube S1, and the second input end of the transformer 630 is connected to the second end of the third switch tube; the primary inductor Lm is connected in parallel with the input end of the transformer 630; and the primary capacitor Cdc is connected in parallel with the DC side Vdc.

[0080] Among them, the secondary circuit 620 is a half-bridge circuit, including a fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7 and an eighth switch tube S8, and the resonant capacitor 650 includes a first capacitor Cr1 and a second capacitor Cr2; the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, the eighth switch tube S8, the second capacitor Cr2 and the first capacitor Cr1 are connected in series in sequence; the first output end of the transformer 630 is connected between the sixth switch tube S6 and the seventh switch tube S7 through the resonant inductor 640, and the second output end of the transformer 630 is connected between the first capacitor Cr1 and the second capacitor Cr2.

[0081] It can be understood that the beneficial effects that can be achieved by the resonant circuit 600 of the embodiment of the present application can refer to the beneficial effects of the current control method of any of the aforementioned embodiments, and will not be repeated here.

[0082] The present application also provides an energy storage inverter device, which includes the resonant circuit of any of the above embodiments. It is understood that the beneficial effects that can be achieved by the energy storage inverter device can refer to the beneficial effects of the resonant circuit of the above embodiments, which will not be repeated here.

[0083] An embodiment of the present application further provides a computer storage medium, which stores a computer program. When the computer program is executed by a processor, the processor executes the above-mentioned current control method.

[0084] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer storage medium or transmitted through the computer storage medium. The computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, etc. that contains one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0085] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes. In the absence of conflict, the technical features in this embodiment and the implementation scheme can be combined arbitrarily.

[0086] The embodiments described above are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the protection scope determined by the claims of the present application.

Claims

1. A current control method for a resonant circuit, characterized in that: The resonant circuit comprises a primary circuit, a secondary circuit, a resonant inductor and a resonant capacitor, the primary circuit is connected to the secondary circuit via the resonant inductor, the resonant capacitor is connected in parallel with the secondary circuit, the primary circuit is used to connect to the DC side, and the secondary circuit is used to connect to the AC side; The current control method comprises: Acquire an inner phase shift angle of the primary circuit and an outer phase shift angle between the primary circuit and the secondary circuit; Acquiring a DC voltage on the DC side and an AC voltage on the AC side; Obtaining a target current effective value according to the inner phase shift angle, the outer phase shift angle, the DC voltage, the AC voltage, and a preset current effective value algorithm; The operating parameters of the primary circuit and the secondary circuit are adjusted according to the target current effective value.

2. The current control method according to claim 1, characterized in that: The step of obtaining a target current effective value according to the inner phase shift angle, the outer phase shift angle, the DC voltage, the AC voltage, and a preset current effective value algorithm includes: Obtaining a primary voltage according to the inner phase shift angle and the DC voltage, and obtaining a secondary voltage according to the outer phase shift angle and the AC voltage; Calculating the resonant current amplitude of the resonant inductor according to the primary voltage and the secondary voltage; The target current effective value is obtained according to the resonant current amplitude and preset soft switching constraints.

3. The current control method according to claim 2, characterized in that: The obtaining of the primary voltage according to the inner phase shift angle and the DC voltage, and the obtaining of the secondary voltage according to the outer phase shift angle and the AC voltage comprises: Obtaining an expression of the primary voltage based on a fundamental wave analysis method using the inner phase shift angle and the DC voltage; The external phase shift angle and the AC voltage are used to obtain an expression for the secondary voltage based on a fundamental wave analysis method.

4. The current control method according to claim 3, characterized in that: The obtaining the resonant current amplitude of the resonant inductor according to the primary voltage and the secondary voltage comprises: Obtaining a resonant current expression according to the expression of the primary voltage, the expression of the secondary voltage and the resonant impedance, wherein the resonant impedance is obtained based on the resonant inductance and the resonant capacitance; The current amplitude expression is obtained according to the resonant current expression, which is the resonant current amplitude.

5. The current control method according to claim 4, characterized in that: The step of obtaining the target current effective value according to the resonant current amplitude and the preset soft switching constraint condition includes: Under the soft switching constraint condition, a corresponding value of the current amplitude expression based on a target gain ratio is obtained as the target current effective value, and the target gain ratio is based on a voltage gain ratio between the primary voltage and the secondary voltage.

6. The current control method according to claim 4, characterized in that: The step of obtaining the target current effective value according to the resonant current amplitude and the preset soft switching constraint condition includes: Under the soft switching constraint condition, the minimum value of the current amplitude expression is obtained as the target current effective value.

7. A resonant circuit, characterized in that: It includes a primary circuit, a secondary circuit, a transformer, a resonant inductor, a resonant capacitor and a controller, wherein the primary circuit is connected to the secondary circuit through the transformer and the resonant inductor, the resonant inductor is connected in series with the secondary circuit, the resonant capacitor is connected in parallel with the secondary circuit, the primary circuit is used to connect to the DC side, and the secondary circuit is used to connect to the AC side; The controller is connected to the primary circuit and the secondary circuit, and is used to obtain a target current effective value according to an internal phase shift angle of the primary circuit, an external phase shift angle between the primary circuit and the secondary circuit, a DC voltage on the DC side, an AC voltage on the AC side, and a preset current effective value algorithm, and adjust operating parameters of the primary circuit and the secondary circuit according to the target current effective value.

8. The resonant circuit according to claim 7, characterized in that The primary circuit is a full-bridge circuit, including a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a primary inductor and a primary capacitor; The first end of the first switch tube is used to connect the positive electrode of the DC side, and the second end of the first switch tube is connected to the first end of the second switch tube; the second end of the second switch tube is used to connect the negative electrode of the DC side; the first end of the third switch tube is connected to the first end of the first switch tube, and the second end of the third switch tube is connected to the first end of the fourth switch tube; the second end of the fourth switch tube is connected to the second end of the second switch tube; The first input end of the transformer is connected to the second end of the first switch tube, and the second input end of the transformer is connected to the second end of the third switch tube; the primary inductor is connected in parallel with the input end of the transformer; and the primary capacitor is connected in parallel with the DC side.

9. The resonant circuit according to claim 7, characterized in that: The secondary circuit is a half-bridge circuit, including a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube, and the resonant capacitor includes a first capacitor and a second capacitor; The fifth switch tube, the sixth switch tube, the seventh switch tube, the eighth switch tube, the second capacitor and the first capacitor are connected in series in sequence; the first output end of the transformer is connected between the sixth switch tube and the seventh switch tube through the resonant inductor, and the second output end of the transformer is connected between the first capacitor and the second capacitor.

10. An energy storage inverter device, characterized in that: Comprising the resonant circuit as claimed in any one of claims 7 to 9.

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