Inverter circuit, four-quadrant control method thereof and energy storage inversion equipment

Abstract

The invention discloses an inverter circuit and a four-quadrant control method thereof and energy storage inverter equipment, the inverter circuit comprises a primary side circuit and a secondary side circuit, the primary side circuit is connected with the secondary side circuit through a resonant inductor, the primary side circuit is used for being connected with the direct current side of the inverter circuit, and the secondary side circuit is used for being connected with the direct current side of the inverter circuit. The secondary side circuit is used for being connected with the alternating current side of the inverter circuit; the four-quadrant control method comprises the following steps: obtaining a target current of the alternating current side of the inverter circuit according to a target angle of the inverter circuit based on four-quadrant operation; acquiring a voltage instantaneous value of the alternating current side; and adjusting the inverter circuit according to the target current and the voltage instantaneous value so as to enable the inverter circuit to operate at the target angle in four quadrants. According to the invention, the inverter circuit can operate in a four-quadrant full range.

Description

Technical Field

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

[0002] At present, as an important component of energy storage inverter equipment, the performance requirements of inverter circuits are getting higher and higher. In the face of different application scenarios, inverter circuits not only need to stably convert DC power into AC power, but also need to adjust their own working conditions according to grid fluctuations and load changes.

[0003] In the prior art, the inverter circuit of the energy storage inverter device cannot achieve full-range operation in the four-quadrants, and therefore has low adaptability to grid fluctuations and load changes, which in turn affects the stability of the inverter circuit. Summary of the invention

[0004] In view of this, the present application provides an inverter circuit and a four-quadrant control method thereof and an energy storage inverter device, which are used to enable the inverter circuit to operate in the full range of the four quadrants. The technical solution of the present application is as follows: In a first aspect, the present application provides a four-quadrant control method for an inverter circuit, wherein the inverter circuit comprises a primary circuit and a secondary circuit, wherein the primary circuit is connected to the secondary circuit via a resonant inductor, the primary circuit is used to connect the DC side of the inverter circuit, and the secondary circuit is used to connect the AC side of the inverter circuit; the four-quadrant control method comprises: obtaining a target current of the AC side of the inverter circuit according to a target angle of the inverter circuit based on four-quadrant operation; obtaining an instantaneous value of the voltage on the AC side; and adjusting the inverter circuit according to the target current and the instantaneous value of the voltage so that the inverter circuit operates in four quadrants at the target angle.

[0005] In one embodiment of the present application, the target current of the AC side of the inverter circuit is obtained according to the target angle of the inverter circuit based on four-quadrant operation, including: obtaining the AC current and AC voltage on the AC side; obtaining the AC side current peak value according to the AC current; obtaining the lag angle of the AC current lagging behind the AC voltage; and obtaining the target current according to the AC side current peak value, the lag angle and the target angle.

[0006] In one embodiment of the present application, the inverter circuit is adjusted according to the target current and the instantaneous value of the voltage so that the four-quadrant inverter circuit operates at the target angle, including: obtaining the target external phase shift angle between the primary circuit and the secondary circuit according to the target current and the instantaneous value of the voltage; and the inverter circuit is adjusted according to the target external phase shift angle so that the four-quadrant inverter circuit operates at the target angle.

[0007] In one embodiment of the present application, the target external phase shift angle between the primary circuit and the secondary circuit is obtained according to the target current and the instantaneous value of the voltage, including: constructing an instantaneous power expression of the inverter circuit based on the phase shift angle parameter; obtaining the target external phase shift angle according to the instantaneous power expression, the target current and the instantaneous value of the voltage.

[0008] In one embodiment of the present application, the instantaneous power expression based on the phase shift angle parameter of the inverter circuit is constructed, including: obtaining the inner phase shift angle of the primary circuit, and the outer phase shift angle between the primary circuit and the secondary circuit; obtaining the DC voltage on the DC side, and the AC voltage on the AC side; constructing a primary voltage expression according to the inner phase shift angle and the DC voltage, and constructing a secondary voltage expression according to the outer phase shift angle and the AC voltage; and obtaining the instantaneous power expression according to the primary voltage expression and the secondary voltage expression.

[0009] A second aspect of the present application provides an inverter 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 via 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 power grid via the AC side; the controller connects the primary circuit and the secondary circuit, and the controller is used to obtain a target current on the AC side of the inverter circuit according to a target angle of the inverter circuit based on four-quadrant operation, obtain an instantaneous value of the voltage on the AC side, and adjust the inverter circuit according to the target current and the instantaneous value of the voltage so that the inverter circuit operates in the four-quadrant at the target angle.

[0010] In one embodiment of the present application, the controller is also used to obtain the target external phase shift angle between the primary circuit and the secondary circuit based on the target current and the instantaneous value of the voltage, and adjust the inverter circuit according to the target external phase shift angle so that the four-quadrant inverter circuit operates at the target angle.

[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 inverter circuit described above.

[0014] The present application obtains a given target current on the AC side of the inverter circuit according to the target angle of the inverter based on the four-quadrant operation, and then adjusts the inverter circuit according to the target current and the instantaneous value of the inverter voltage, so that the four-quadrant operation of the inverter circuit is at the target angle, thereby realizing the full range of four-quadrant operation of the inverter circuit and improving the stability of the inverter circuit. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] Figure 2 It is a flow chart of a four-quadrant control method for an inverter circuit provided in an embodiment of the present application.

[0017] Figure 3 It is a flow chart of a method for obtaining a target current provided in an embodiment of the present application.

[0018] Figure 4 It is a schematic diagram of a flow chart of regulating an inverter circuit provided in an embodiment of the present application.

[0019] Figure 5 It is a schematic diagram of a process for obtaining a target external phase shift angle provided in an embodiment of the present application.

[0020] Figure 6 It is a flow chart of constructing an instantaneous power expression provided in an embodiment of the present application.

[0021] Figure 7 It is a schematic block diagram of an inverter circuit provided in an embodiment of the present application.

[0022] Figure 8 It is a circuit diagram of an inverter circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] 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.

[0024] 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.

[0025] At present, as an important component of energy storage inverter equipment, the performance requirements of inverter circuits are getting higher and higher. In the face of different application scenarios, inverter circuits not only need to stably convert DC power into AC power, but also need to adjust their own working conditions according to grid fluctuations and load changes.

[0026] In the prior art, the inverter circuit of the energy storage inverter device cannot achieve full-range operation in the four-quadrants, and therefore has low adaptability to grid fluctuations and load changes, which in turn affects the stability of the inverter circuit.

[0027] The present application provides an inverter circuit and a four-quadrant control method thereof, which are used to enable the inverter circuit to operate in the full range of the four quadrants.

[0028] Please refer to Figure 1 , Figure 1 An equivalent schematic diagram of an inverter circuit provided in an embodiment of the present application, wherein the inverter circuit 100 includes a primary circuit 110 , a secondary circuit 120 , a resonant inductor 130 and a resonant capacitor 140 .

[0029] 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.

[0030] It can be understood that when the inverter 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.

[0031] Next, combine Figure 1 A four-quadrant control method for an inverter circuit provided in an embodiment of the present application is introduced, please refer to Figure 2 , specifically including the following steps: Step S21: Obtaining a target current on the AC side of the inverter circuit according to a target angle of the inverter circuit based on four-quadrant operation.

[0032] In the embodiment of the present application, the inverter circuit can also be connected to the controller, which controls it to work and execute the various steps in this embodiment. For example, in an energy storage inverter device provided with an inverter circuit, the primary circuit and the secondary circuit of the inverter 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 the inverter circuit to work.

[0033] It can be understood that after controlling the inverter circuit to work, the controller can also receive external instructions to adjust the target angle of the inverter circuit in the four-quadrant operation according to the external instructions to correspond to the required working conditions. Among them, the angle of the inverter circuit in the four-quadrant operation is the angle at which the output AC current lags behind the AC voltage. When the angle is in the first quadrant, it means that the inverter circuit is in the working condition of outputting active power and outputting reactive power. When the angle is in the second quadrant, it means that the inverter circuit is in the working condition of inputting active power and outputting reactive power. When the angle is in the third quadrant, it means that the inverter circuit is in the working condition of inputting active power and inputting reactive power. When the angle is in the fourth quadrant, it means that the inverter circuit is in the working condition of inputting active power and outputting reactive power. Therefore, by controlling the angle of the inverter circuit in the four-quadrant operation, the inverter circuit can be controlled to work in the corresponding working condition. In some embodiments, the controller can also receive the working condition control instruction transmitted externally, and obtain the corresponding target angle of the four-quadrant operation according to the working condition control instruction.

[0034] After obtaining the target angle, the controller will obtain the target current on the AC side of the inverter circuit according to the target angle, that is, a given target current on the AC side can be calculated according to the target angle.

[0035] Step S22: Acquire the instantaneous value of the voltage on the AC side.

[0036] In an embodiment of the present application, the controller can be connected to the AC side of the inverter circuit to obtain the AC voltage on the AC side, and then obtain the instantaneous value of the AC voltage. In some embodiments, an AC voltage sampling circuit can be provided on the AC side, and the AC voltage sampling circuit is used to collect the AC voltage on the AC side and transmit it to the controller.

[0037] Step S23: adjusting the inverter circuit according to the target current and the instantaneous voltage value, so that the four quadrants of the inverter circuit operate at the target angle.

[0038] In the embodiment of the present application, after obtaining the target current and the instantaneous value of the voltage, the controller will adjust the inverter circuit according to the instantaneous value of the voltage, and finally make the inverter circuit operate at the target angle of the four-quadrant operation to correspond to the required working conditions. For example, the controller can first control the inverter circuit to output the target current, and then adjust the working parameters of the inverter circuit according to the instantaneous value of the voltage, and finally make the output current of the inverter circuit lag behind the output voltage at the target angle, so that the inverter circuit operates at the target angle in the four quadrants.

[0039] It can be understood that the present application obtains a given target current on the AC side of the inverter circuit according to the target angle of the inverter based on the four-quadrant operation, and then adjusts the inverter circuit according to the target current and the instantaneous value of the inverter voltage, so that the four-quadrant operation of the inverter circuit is at the target angle, thereby realizing the full range of four-quadrant operation of the inverter circuit and improving the stability of the inverter circuit.

[0040] In some embodiments, Figure 3 As shown, obtaining the target current in the above step S21 may specifically include the following steps: Step S31: Acquire the AC current and AC voltage on the AC side.

[0041] In the embodiment of the present application, a current sampling circuit and a voltage sampling circuit may also be provided in the inverter circuit, wherein the current sampling circuit is used to collect the AC current on the AC side of the inverter circuit and transmit it to the controller, and the voltage sampling circuit is used to collect the AC voltage on the AC side of the inverter circuit and transmit it to the controller.

[0042] Step S32: obtaining the AC side current peak value according to the AC current.

[0043] In the embodiment of the present application, after the controller obtains the alternating current through the current sampling circuit, it can obtain its current peak value according to the alternating current.

[0044] Step S33: obtaining a lag angle of the AC current lagging behind the AC voltage.

[0045] In an embodiment of the present application, after the controller obtains the AC current through the current acquisition circuit and obtains the AC voltage through the voltage acquisition circuit, it can obtain the lag angle of the current AC current lagging behind the AC voltage based on the current AC current and AC voltage.

[0046] Step S34: Obtain the target current according to the AC side current peak value, the hysteresis angle and the target angle.

[0047] In the embodiment of the present application, the controller can construct an expression of the target current according to the obtained AC side voltage peak value, hysteresis angle and target angle, so as to obtain the target current. The expression of the target current can be: ; In the formula, is the target current, is the peak current on the AC side, is the target angle, is the hysteresis angle.

[0048] In some embodiments, Figure 4 As shown, in the above step S23, adjusting the inverter circuit according to the target current and the instantaneous voltage value may specifically include the following steps: Step S41: Obtaining a target outward shift phase angle between the primary circuit and the secondary circuit according to the target current and voltage instantaneous values.

[0049] Step S42: adjusting the inverter circuit according to the target external phase shift angle so that the four quadrants of the inverter circuit operate at the target angle.

[0050] In an embodiment of the present application, the controller can calculate the target instantaneous power of the inverter circuit based on the target current and instantaneous voltage values, thereby calculating the above-mentioned target external phase shift angle based on the target instantaneous power, and then adjust the primary circuit and secondary circuit in the inverter circuit according to the target external phase shift angle, so that the four quadrants of the inverter circuit operate at the target angle.

[0051] In some embodiments, Figure 5 As shown, obtaining the target external phase shift angle in the above step S41 may specifically include the following steps: Step S51: constructing an instantaneous power expression of the inverter circuit based on the phase shift angle parameter.

[0052] Step S52: Obtain the target outward shift phase angle according to the instantaneous power expression, the target current and the instantaneous value of the voltage.

[0053] In an embodiment of the present application, a pre-constructed instantaneous power expression based on a phase shift angle parameter may also be preset in the controller, wherein the phase shift angle parameter includes an inner phase shift angle of the primary circuit and an outer phase shift angle between the primary circuit and the secondary circuit. The controller may first calculate the target instantaneous power according to the instantaneous value of the target current and voltage, and then substitute the target instantaneous power into the instantaneous power expression to calculate the corresponding target outer phase shift angle.

[0054] In some embodiments, Figure 6 As shown, constructing the instantaneous power expression in the above step S51 may specifically include the following steps: Step S61: obtaining an inner phase shift angle of the primary circuit and an outer phase shift angle between the primary circuit and the secondary circuit.

[0055] In the embodiment of the present application, the controller can also construct an instantaneous power expression in real time according to the working parameters of the inverter circuit. Among them, after controlling the inverter circuit to work, the controller can obtain the inner phase shift angle of the primary circuit, and obtain the outer phase shift angle between the primary circuit and the secondary circuit. For example, after controlling the inverter circuit to work, the controller can obtain the working parameters such as the frequency and duty cycle of each switching device in the primary circuit and the secondary circuit, and calculate the current inner phase shift angle and outer phase shift angle of the inverter circuit according to the working parameters of each switching device.

[0056] Step S62: Acquire the DC voltage on the DC side and the AC voltage on the AC side.

[0057] 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.

[0058] Step S63: constructing a primary voltage expression according to the inner phase shift angle and the DC voltage, and constructing a secondary voltage expression according to the outer phase shift angle and the AC voltage.

[0059] In some embodiments, the internal phase shift angle and the DC voltage can be used to obtain the primary voltage expression based on the fundamental wave analysis method. The primary voltage expression constructed based on the fundamental wave analysis method can be: ; In the formula, is the primary voltage, is the DC voltage on the DC side, is the turns ratio of the transformer between the primary voltage and the transformed voltage, is the inner phase angle.

[0060] And, the secondary voltage expression based on the fundamental wave analysis method is obtained by using the external phase shift angle and the AC voltage. The expression of the secondary voltage constructed based on the fundamental wave analysis method can be: ; In the formula, is the secondary voltage, is the AC voltage on the AC side, is the outward shift phase angle.

[0061] Step S64: Obtain an instantaneous power expression according to the primary voltage expression and the secondary voltage expression.

[0062] In the embodiment of the present application, the instantaneous power expression can be further obtained according to the above primary voltage expression and secondary voltage expression: ; In the formula, is the resonant impedance.

[0063] Please refer to Figure 7 An embodiment of the present application provides a schematic block diagram of an inverter circuit, wherein the inverter circuit 700 includes: a primary circuit 710, a secondary circuit 720, a transformer 730, a resonant inductor 740, a resonant capacitor 750 and a controller 760.

[0064] In the embodiment of the present application, the primary circuit 710 is connected to the secondary circuit 720 through the transformer 730 and the resonant inductor 740, the resonant inductor 740 is connected in series with the secondary circuit 720, the resonant capacitor 750 is connected in parallel with the secondary circuit 720, the primary circuit 710 is used to connect the DC side, and the secondary circuit 720 is used to connect the AC side; The controller 760 is connected to the primary circuit 710 and the secondary circuit 720. The controller 760 is used to obtain the target current on the AC side of the inverter circuit 700 according to the target angle of the inverter circuit 700 based on the four-quadrant operation, obtain the instantaneous value of the voltage on the AC side, and adjust the inverter circuit 700 according to the target current and the instantaneous voltage value so that the inverter circuit 700 operates at the target angle in the four-quadrant.

[0065] In some embodiments, the controller 760 also obtains the target external phase shift angle between the primary circuit 710 and the secondary circuit 720 according to the target current and voltage instantaneous values, and adjusts the inverter circuit 700 according to the target external phase shift angle so that the four quadrants of the inverter circuit 700 operate at the target angle.

[0066] In some embodiments, the controller 760 is also used to obtain the AC current and AC voltage on the AC side, obtain the AC side current peak value based on the AC current, obtain the lag angle of the AC current lagging behind the AC voltage, and obtain the target current based on the AC side current peak value, the lag angle and the target angle.

[0067] In some embodiments, the controller 760 is further used to construct an instantaneous power expression of the inverter circuit 700 based on a phase shift angle parameter, and obtain a target external phase shift angle according to the instantaneous power expression, the target current, and the instantaneous value of the voltage.

[0068] In some embodiments, the controller 760 is also used to obtain the inner phase shift angle of the primary circuit 710 and the outer phase shift angle between the primary circuit 710 and the secondary circuit 720, obtain the DC voltage on the DC side and the AC voltage on the AC side, construct a primary voltage expression based on the inner phase shift angle and the DC voltage, construct a secondary voltage expression based on the outer phase shift angle and the AC voltage, and obtain an instantaneous power expression based on the primary voltage expression and the secondary voltage expression.

[0069] Please refer to Figure 8 , Figure 8 A circuit diagram of an inverter circuit 700 provided in an embodiment of the present application is shown in FIG. 7 , wherein the primary circuit 710 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.

[0070] 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.

[0071] The first input end of the transformer 730 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 730; and the primary capacitor Cdc is connected in parallel with the DC side Vdc.

[0072] Among them, the secondary circuit 720 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 730 is connected between the sixth switch tube S6 and the seventh switch tube S7 through the resonant inductor 740, and the second output end of the transformer 730 is connected between the first capacitor Cr1 and the second capacitor Cr2.

[0073] It can be understood that the beneficial effects that can be achieved by the inverter circuit 700 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.

[0074] In the embodiment of the present application, a more detailed functional description of each of the above modules can be referred to the corresponding content of the aforementioned part, which will not be repeated here.

[0075] 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 four-quadrant control method.

[0076] 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 may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer storage medium or transmitted through the computer storage medium. The computer instructions may 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 (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes 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)).

[0077] 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.

[0078] 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 four-quadrant control method for an inverter circuit, characterized in that: The inverter circuit includes a primary circuit and a secondary circuit, the primary circuit is connected to the secondary circuit via a resonant inductor, the primary circuit is used to connect to the DC side of the inverter circuit, and the secondary circuit is used to connect to the AC side of the inverter circuit; The four-quadrant control method comprises: Obtaining a target current of the AC side of the inverter circuit according to a target angle of the inverter circuit based on four-quadrant operation; Obtaining an instantaneous value of voltage on the AC side; The inverter circuit is adjusted according to the target current and the instantaneous value of the voltage, so that the four-quadrant inverter circuit operates at the target angle.

2. The four-quadrant control method according to claim 1, characterized in that: The step of obtaining a target current on the AC side of the inverter circuit according to a target angle of the inverter circuit based on four-quadrant operation includes: Acquiring the AC current and AC voltage of the AC side; Obtaining an AC side current peak value according to the AC current; Obtaining a lag angle at which the alternating current lags behind the alternating voltage; The target current is obtained according to the AC side current peak value, the hysteresis angle and the target angle.

3. The four-quadrant control method according to claim 1, characterized in that: The step of adjusting the inverter circuit according to the target current and the instantaneous voltage value so that the four-quadrant inverter circuit operates at the target angle includes: Obtaining a target external phase shift angle between the primary circuit and the secondary circuit according to the target current and the instantaneous value of the voltage; The inverter circuit is adjusted according to the target external phase shift angle so that the four-quadrant inverter circuit operates at the target angle.

4. The four-quadrant control method according to claim 3, characterized in that: The step of obtaining a target external phase shift angle between the primary circuit and the secondary circuit according to the target current and the instantaneous voltage value includes: Constructing an instantaneous power expression of the inverter circuit based on a phase shift angle parameter; The target external shift phase angle is obtained according to the instantaneous power expression, the target current and the instantaneous value of the voltage.

5. The four-quadrant control method according to claim 4, characterized in that: The instantaneous power expression based on the phase shift angle parameter of the inverter circuit is constructed, comprising: 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; Constructing a primary voltage expression according to the inner phase shift angle and the DC voltage, and constructing a secondary voltage expression according to the outer phase shift angle and the AC voltage; The instantaneous power expression is obtained according to the primary voltage expression and the secondary voltage expression.

6. An inverter 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 power grid through the AC side; The controller is connected to the primary circuit and the secondary circuit. The controller is used to obtain the target current of the AC side of the inverter circuit according to the target angle of the inverter circuit based on four-quadrant operation, obtain the instantaneous value of the voltage on the AC side, and adjust the inverter circuit according to the target current and the instantaneous value of the voltage so that the inverter circuit operates in the four-quadrant at the target angle.

7. The inverter circuit according to claim 6, characterized in that: The controller is also used to obtain a target external phase shift angle between the primary circuit and the secondary circuit according to the target current and the instantaneous value of the voltage, and adjust the inverter circuit according to the target external phase shift angle so that the inverter circuit operates in four quadrants at the target angle.

8. The inverter circuit according to claim 6, 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 inverter circuit according to claim 6, 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: The invention comprises the inverter circuit as claimed in any one of claims 6 to 9.

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