Electric energy transmission control circuit and method, and electric energy transmission system

Abstract

The present disclosure relates to the technical field of power generation and storage, and provides an electric energy transmission control circuit and method, and an electric energy transmission system. The electric energy transmission control circuit of the present disclosure: a measurement module, configured to measure the voltage and current at both ends of a bidirectional buck-boost DC-DC conversion circuit to obtain a measurement result; a control module, configured to determine a target operating state of each switching device of the bidirectional buck-boost DC-DC conversion circuit on the basis of the measurement result; and a driving module, configured to output the voltage to the corresponding switching device on the basis of the target operating state.

Description

Power transmission control circuit and control method and power transmission system

[0001] Cross-reference to related applications

[0002] This application is based on the application with CN application number 202410833940.2 and application date 2024 / 06 / 26, and claims priority thereto, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of power generation and storage, and in particular to a power transmission control circuit and control method and power transmission system. BACKGROUND

[0004] In energy storage related applications, a bidirectional DC(Direct Current, direct current) / DC converter is used as a device between a common DC bus system and a battery pack to realize bidirectional power transmission. The DC-DC converter includes an electrical isolation type and a non-electrical isolation type.

[0005] A single-switch boost or single-switch buck DC-DC converter can realize voltage boosting or voltage bucking. However, if the input voltage and the output voltage are similar, the single-switch module cannot be used. Using a single-switch boost-buck DC-DC converter changes the polarity of the output voltage. SUMMARY

[0006] One object of the present disclosure is to improve the flexibility of power transmission.

[0007] According to an aspect of some embodiments of the present disclosure, a power transmission control circuit is provided, comprising: a detection module configured to detect the voltage and current at both ends of a bidirectional boost-buck DC-DC conversion circuit and obtain a detection result; a control module configured to determine the target working state of each switching device of the bidirectional boost-buck DC-DC conversion circuit according to the detection result; and a driving module configured to output a voltage to the corresponding switching device according to the target working state.

[0008] In the technical solution of the embodiments of the present disclosure, the voltage and current state at both ends of the bidirectional boost-buck DC-DC conversion circuit can be detected in real time, the control strategy of the bidirectional boost-buck DC-DC conversion circuit is determined according to the real-time detection result, and the working mode of the bidirectional boost-buck DC-DC conversion circuit is adjusted through the control of the switching devices in the bidirectional boost-buck DC-DC conversion circuit, thereby improving the control flexibility and real-time performance of the bidirectional boost-buck DC-DC conversion circuit, and further improving the accuracy, flexibility and convenience of the circuits on both sides of the bidirectional boost-buck DC-DC conversion circuit for bidirectional power transmission.

[0009] In some embodiments, the control module is configured to determine a target operation mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection result; and determine a target operation state of each switching device according to the target operation mode, wherein the target operation state comprises always-on, always-off, and periodic switching under control of the driving voltage.

[0010] In the technical solution in the embodiments of the present disclosure, the control module first determines the target operation mode, and then determines the target operation state according to the relationship between the target operation mode and the operation state of each switching device, thereby improving the accuracy of the control of the switching device and reducing the processing burden of the control module.

[0011] In some embodiments, the control module is configured to determine a current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the current; determine a buck-boost mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the voltage; and determine the target operation mode according to the current transmission direction and the buck-boost mode.

[0012] In the technical solution in the embodiments of the present disclosure, the target operation mode can be determined from the current transmission direction and the change of the voltage, which not only makes the current transmission direction consistent with the current detection result, but also makes the output voltage meet the demand of the current receiving side, thereby improving the stability of the bus voltage, improving the delicacy and accuracy of the operation mode adjustment, and being conducive to further improving the accuracy of the bidirectional transmission of electric energy.

[0013] In some embodiments, the control module is further configured to determine a duty cycle of the driving voltage according to the detection result; and the driving module is configured to output the driving voltage to the two switching devices according to the duty cycle of the driving voltage.

[0014] In the technical solution in the embodiments of the present disclosure, the duty cycle of the switching device can be controlled to adjust the boost amplitude and the buck amplitude, thereby improving the flexibility of the buck-boost control and improving the control ability of the control circuit to the bidirectional buck-boost DC-DC conversion circuit.

[0015] In some embodiments, the control module is configured to determine a buck-boost amplitude according to the detection result of the voltage; and determine a duty cycle of the driving voltage according to the buck-boost amplitude.

[0016] In the technical solution in the embodiments of the present disclosure, the buck-boost amplitude can be determined according to the detection result of the voltage, thereby improving the matching degree of the output voltage and the demand of the receiving end and further improving the flexibility of the buck-boost adjustment, which is conducive to further improving the stability of the bus voltage.

[0017] In some embodiments, the first end of the bidirectional step-up / down DC-DC conversion circuit is connected to an inverter module connected to a power grid, and the second end is connected to an energy storage module, wherein the control module is configured to perform at least one of the following: in a case where it is determined according to the detection result that there is power supply on the power grid side, determining the target working state as the working state of the switching device in the working mode of supplying power from the first end to the second end; in a case where it is determined according to the detection result that there is no power supply on the power grid side, determining the target working state as the working state of the switching device in the working mode of supplying power from the second end to the first end.

[0018] In the technical solution in the embodiments of the present disclosure, in a case where the bidirectional step-up / down DC-DC conversion circuit is used as a transmission circuit between a power grid and an energy storage module, the working mode of the bidirectional step-up / down DC-DC conversion circuit can be automatically adjusted in real time according to whether there is power supply on the power grid side, so that the energy storage module can store power from the power grid, and at the same time, the energy storage can be used to supply power to an alternating current device close to the power grid side, thereby improving the operation stability of the power consumption network.

[0019] In some embodiments, the first end of the bidirectional step-up / down DC-DC conversion circuit is connected to a photovoltaic DC-DC module connected to a photovoltaic circuit, and the second end is connected to an energy storage module, wherein the control module is configured to: in a case where it is determined according to the detection result that there is power supply on the photovoltaic circuit side, determine the target working state as the working state of the switching device in the working mode of supplying power from the first end to the second end.

[0020] In the technical solution in the embodiments of the present disclosure, in a case where the bidirectional step-up / down DC-DC conversion circuit is used as a transmission circuit between a photovoltaic power generation device and an energy storage module, whether the photovoltaic power generation device stores power to the energy storage module can be flexibly switched, the flexibility of photovoltaic power generation storage is improved, and the control ability of the control circuit to the power flow in the system is improved.

[0021] In some embodiments, the second end of the bidirectional step-up / down DC-DC conversion circuit is connected to an energy storage module, and an inverter module connected to a power grid and a photovoltaic DC-DC module connected to a photovoltaic circuit are connected in parallel at the first end of the bidirectional step-up / down DC-DC conversion circuit, wherein the control module is configured to perform at least one of the following: in a case where it is determined according to the detection result that there is power supply on the power grid, or there is power supply on the photovoltaic circuit side, determining the target working state as the working state of the switching device in the working mode of supplying power from the first end to the second end; in a case where it is determined according to the detection result that there is no power supply on the power grid side and there is power supply on the energy storage module, determining the target working state as the working state of the switching device in the working mode of supplying power from the second end to the first end.

[0022] In the technical solutions in the embodiments of the present disclosure, the power transmission between the power grid and the energy storage module and the power transmission from the photovoltaic circuit to the energy storage module can be flexibly controlled, the power supply conditions of the power grid, the photovoltaic circuit and the energy storage module are determined in real time according to the detection results, and timely adjustment is performed, so that the utilization rate and the energy storage efficiency of the power are improved, and the operation stability of the equipment operated by the power grid is improved.

[0023] In some embodiments, the first end of the bidirectional voltage-lifting DC-DC conversion circuit is connected with the first energy storage unit, and the second end is connected with the second energy storage unit, and the control module is further configured to: in a case where it is determined to supply power from the first energy storage unit to the second energy storage unit, determine that the target working state of the switching device is a working state in a working mode of supplying power from the first end to the second end; and in a case where it is determined to supply power from the second energy storage unit to the first energy storage unit, determine that the target working state of the switching device is a working state in a working mode of supplying power from the second end to the first end.

[0024] In the technical solutions in the embodiments of the present disclosure, the current conduction direction between the energy storage units can be controlled, so that the power can be flexibly transferred between the energy storage units, and the flexibility of the energy storage control of the energy storage units is improved.

[0025] In some embodiments, the control module is further configured to: determine the voltage-lifting and voltage-lowering mode and the voltage-lifting and voltage-lowering amplitude according to the voltage difference between the first energy storage unit and the second energy storage unit; determine, according to the voltage-lifting and voltage-lowering mode, that the target working state is a working state of the switching device corresponding to the voltage-lifting and voltage-lowering mode in a case where the current transmission direction is determined; and determine the duty cycle of the driving voltage according to the voltage-lifting and voltage-lowering amplitude.

[0026] In the technical solutions in the embodiments of the present disclosure, after the flow direction of the power between the energy storage units is determined, it is further determined whether to use the voltage-lifting mode or the voltage-lowering mode, so as to determine the working state of the required switching device; on this basis, the voltage-lifting and voltage-lowering amplitude is controlled by adjusting the duty cycle, so as to facilitate the energy exchange between the energy storage units of different voltage levels, and further improve the flexibility of the energy storage control of the energy storage units.

[0027] In some embodiments, the control circuit further comprises: an auxiliary power supply module connected with the two ends of the bidirectional voltage-lifting DC-DC conversion circuit, and connected with the detection module, the control module and the driving module, and configured to supply power to the detection module, the control module and the driving module by using the power from at least one end of the bidirectional voltage-lifting DC-DC conversion circuit.

[0028] In the technical solutions in the embodiments of the present disclosure, the auxiliary power module can obtain electric energy from the circuit connected to both ends of the bidirectional buck-boost DC-DC conversion circuit, and when any circuit at either end has the ability to supply electric energy, the auxiliary power module can supply power to other parts of the control circuit, thereby improving the stability of the operation of the control circuit; without using an external power supply, the burden of line deployment is reduced.

[0029] In some embodiments, the detection module is further configured to detect the temperature of the switching device of the bidirectional buck-boost DC-DC conversion circuit; and the control module is further configured to determine to disconnect the bidirectional buck-boost DC-DC conversion circuit when the temperature exceeds a predetermined temperature range.

[0030] In the technical solutions in the embodiments of the present disclosure, the control circuit can also detect the temperature of the switching device and timely cut off the current transmission in the case of abnormal temperature, thereby reducing the probability of danger and improving the safety of the device.

[0031] According to an aspect of some other embodiments of the present disclosure, an electric energy transmission system is provided, comprising: a bidirectional buck-boost DC-DC conversion circuit comprising at least four switching devices, each of which is connected to an electric energy transmission control circuit; and any one of the electric energy transmission control circuits mentioned above, which is configured to control the target working state of each switching device in the bidirectional buck-boost DC-DC conversion circuit.

[0032] In the technical solutions in the embodiments of the present disclosure, the electric energy transmission control circuit in the electric energy transmission system can detect the voltage and current state of both ends of the bidirectional buck-boost DC-DC conversion circuit in real time, determine the control strategy for the bidirectional buck-boost DC-DC conversion circuit according to the real-time detection result, and realize the adjustment of the working mode of the bidirectional buck-boost DC-DC conversion circuit through the control of the switching device in the bidirectional buck-boost DC-DC conversion circuit, thereby improving the control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit, and further improving the accuracy, flexibility and convenience of the electric energy bidirectional transmission of the circuits on both sides of the bidirectional buck-boost DC-DC conversion circuit.

[0033] In some embodiments, the bidirectional buck-boost DC-DC conversion circuit comprises a first bidirectional buck-boost DC-DC conversion circuit between the power grid and the power storage module, which is configured to perform voltage adjustment and electric energy transmission between the power grid and the power storage module.

[0034] In the technical solutions in the embodiments of the present disclosure, the bidirectional step-up / down DC-DC conversion circuit controlled by the electric energy transmission control circuit can be deployed between the power grid and the power storage module, so that the working mode of the bidirectional step-up / down DC-DC conversion circuit is automatically adjusted in real time according to whether the power supply exists on the power grid side, and the power storage module can store energy by using the power grid power, and at the same time, the stored energy can be used to supply power to the alternating current equipment close to the power grid side, thereby improving the operation stability of the power consumption network.

[0035] In some embodiments, the first bidirectional step-up / down DC-DC conversion circuit is further configured to perform voltage step-up / down adjustment and electric energy transmission between the photovoltaic circuit and the power storage module.

[0036] In the technical solutions in the embodiments of the present disclosure, the bidirectional step-up / down DC-DC conversion circuit controlled by the electric energy transmission control circuit can be deployed between the photovoltaic power generation device and the power storage module, so that whether the photovoltaic power generation stores electric energy in the power storage module can be flexibly switched, the flexibility of photovoltaic power generation storage is improved, and the control ability of the control circuit to the electric energy flow direction in the system is improved.

[0037] In some embodiments, the bidirectional step-up / down DC-DC conversion circuit includes a second bidirectional step-up / down DC-DC conversion circuit located between two power storage units and configured to perform voltage step-up / down adjustment and electric energy transmission between the connected two power storage units.

[0038] In the technical solutions in the embodiments of the present disclosure, the bidirectional step-up / down DC-DC conversion circuit controlled by the electric energy transmission control circuit can be deployed between the power storage units, and the current conduction direction between the power storage units is controlled, so that the electric energy can be flexibly transferred between the power storage units, and the flexibility of the power storage control of the power storage units is improved.

[0039] In some embodiments, the electric energy transmission system further includes an inverter module located between the power grid and the first bidirectional step-up / down DC-DC conversion circuit and configured to perform at least one of the following: converting alternating current of a first voltage from the power grid into direct current of a second voltage to be delivered to the first end of the first bidirectional step-up / down DC-DC conversion circuit; and converting direct current of the second voltage from the first bidirectional step-up / down DC-DC conversion circuit into alternating current of the first voltage to be delivered to the alternating current appliance for use.

[0040] In the technical solutions in the embodiments of the present disclosure, the inverter module can realize AC-DC conversion from the power grid to the direct current bus and DC-AC conversion from the direct current bus to the power grid, so as to facilitate charging of the power storage module, and at the same time, the alternating current appliance on the power grid side can work by using the stored energy, thereby improving the stability of the appliance working.

[0041] In some embodiments, the electric energy transmission system further comprises: a photovoltaic DC-DC conversion module located between the photovoltaic interface connected to the photovoltaic panel and the first bidirectional buck-boost DC-DC conversion circuit, configured to convert direct current of the third voltage from the photovoltaic interface into direct current of the fourth voltage, and deliver the direct current of the fourth voltage to the first end of the first bidirectional buck-boost DC-DC conversion circuit, wherein the photovoltaic DC-DC conversion module comprises a transistor for intercepting current flowing from the first end of the first bidirectional buck-boost DC-DC conversion circuit to the photovoltaic interface.

[0042] In the technical solution in the embodiments of the present disclosure, the photovoltaic DC-DC conversion module can convert the electric energy from the photovoltaic panel into a voltage, facilitating grid connection to the DC bus; the transistor can prevent the electric energy of the storage module from being transmitted to the photovoltaic panel, thereby improving the safety of the photovoltaic circuit.

[0043] In some embodiments, the photovoltaic DC-DC conversion module is a four-switch buck-boost circuit.

[0044] In the technical solution in the embodiments of the present disclosure, the four-switch buck-boost circuit can avoid changing the polarity of the current, thereby improving the matching degree with the whole machine.

[0045] In some embodiments, each switching device of the photovoltaic DC-DC conversion module is connected to the electric energy transmission control circuit; the electric energy transmission control circuit is further configured to: detect the voltage value of the end of the photovoltaic DC-DC conversion module connected to the photovoltaic interface, determine the buck-boost mode and the buck-boost amplitude of the photovoltaic DC-DC conversion module according to the voltage value and the target voltage of the photovoltaic DC-DC conversion; determine the target working state of the switching device of the photovoltaic DC-DC conversion module according to the buck-boost mode, which is the working state conforming to the corresponding buck-boost mode when the current direction is from the photovoltaic interface to the first bidirectional buck-boost DC-DC conversion circuit; determine the target duty cycle according to the buck-boost amplitude of the photovoltaic DC-DC conversion module; and output the voltage to the corresponding switching device of the photovoltaic DC-DC conversion module according to the target duty cycle.

[0046] In the technical solution in the embodiments of the present disclosure, the working mode of the photovoltaic DC-DC conversion module can also be controlled and adjusted by the electric energy transmission control circuit, thereby further improving the flexibility of the system.

[0047] In some embodiments, the bidirectional buck-boost DC-DC conversion circuit comprises at least one of: at least two safety tubes located at both ends of the bidirectional buck-boost DC-DC conversion circuit; and at least two sampling resistors located at both ends of the bidirectional buck-boost DC-DC conversion circuit, wherein the electric energy transmission control circuit is configured to obtain a detection result according to the resistance value of the sampling resistor and the current passing through the sampling resistor.

[0048] The safety of the circuit is improved by arranging the safety tube at the two ends to prevent short circuit caused by sudden change of current on either side.

[0049] In some embodiments, the photovoltaic DC-DC conversion module further comprises a third safety tube at one end of the photovoltaic DC-DC conversion module connected to the photovoltaic interface.

[0050] The safety of the circuit is improved by arranging the safety tube at the two ends to prevent short circuit caused by sudden change of current on either side.

[0051] According to another aspect of some embodiments of the present disclosure, an electric energy transmission control method is provided, comprising: obtaining detection results of voltage and current at two ends of a bidirectional buck-boost DC-DC conversion circuit; determining a target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection results; and determining a voltage output to the corresponding switching device according to the target working state.

[0052] The control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit are improved by determining the control strategy of the bidirectional buck-boost DC-DC conversion circuit according to real-time detection results of the bidirectional buck-boost DC-DC conversion circuit, and adjusting the working mode of the bidirectional buck-boost DC-DC conversion circuit by controlling the switching devices in the bidirectional buck-boost DC-DC conversion circuit, thereby improving the accuracy, flexibility and convenience of the electric energy bidirectional transmission of the circuits on both sides of the bidirectional buck-boost DC-DC conversion circuit.

[0053] In some embodiments, determining the target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection results comprises: determining a target working mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection results; and determining the target working state of each switching device according to the target working mode, wherein the target working state comprises always on, always off, and periodic switching under the control of a driving voltage.

[0054] The accuracy of the switching device control is improved and the processing burden is reduced by first determining the target working mode, and then determining the target working state according to the relationship between the target working mode and the working state of each switching device.

[0055] In some embodiments, determining the target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection result includes: determining the current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the current; determining the buck-boost mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the voltage; and determining the target working mode according to the current transmission direction and the buck-boost mode.

[0056] In the technical solution in the embodiments of the present disclosure, the target working mode can be determined from the current transmission direction and the change of the voltage, the current transmission direction is consistent with the current detection result, and the output voltage meets the demand of the current receiving side, the stability of the bus voltage is improved, the delicacy and accuracy of the working mode adjustment are improved, and the accuracy of the bidirectional power transmission is further improved.

[0057] In some embodiments, the power transmission control method further includes: determining the duty cycle of the driving voltage according to the detection result; and determining the voltage output to the corresponding switching device according to the target working state, including: determining the driving voltage output to the two switching devices according to the duty cycle of the driving voltage.

[0058] In the technical solution in the embodiments of the present disclosure, the boost amplitude and the buck amplitude can be adjusted by controlling the duty cycle of the switching device, the flexibility of the buck-boost control is improved, and the control ability of the control circuit to the bidirectional buck-boost DC-DC conversion circuit is improved.

[0059] In some embodiments, the power transmission control method further includes: determining the current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the demand of the current transmission direction; determining the buck-boost mode and the buck-boost amplitude according to the voltage difference between the two ends of the bidirectional buck-boost DC-DC conversion circuit; determining the target working state of the switching device that meets the corresponding buck-boost mode in the case of the determined current transmission direction according to the buck-boost mode; and determining the duty cycle of the driving voltage according to the buck-boost amplitude.

[0060] In the technical solution in the embodiments of the present disclosure, after the flow direction of the power is determined, it is further determined whether the boost mode or the buck mode is used, so as to determine the working state of the required switching device; on this basis, the buck-boost amplitude is controlled by adjusting the duty cycle, and the flexibility of the control is improved. In the case of being applied to control the circuit between the energy storage units, the energy exchange between the batteries of different voltage levels is facilitated, and the flexibility of the energy storage unit energy storage control is further improved.

[0061] In some embodiments, the power transmission control method further comprises: obtaining a voltage value of an end of the photovoltaic DC-DC conversion module connected to the photovoltaic interface, wherein the photovoltaic DC-DC conversion module is located between the photovoltaic interface connected to the photovoltaic panel and the first bidirectional buck-boost DC-DC conversion circuit, and is configured to convert direct current of the third voltage from the photovoltaic interface into direct current of the fourth voltage; determining a buck-boost mode and a buck-boost amplitude of the photovoltaic DC-DC conversion module according to the voltage value and a target voltage of the photovoltaic DC-DC conversion; determining a target working state of a switching device of the photovoltaic DC-DC conversion module according to the buck-boost mode, wherein the target working state is a working state corresponding to the buck-boost mode and meets the current direction from the photovoltaic interface to the first bidirectional buck-boost DC-DC conversion circuit; determining a target duty cycle according to the buck-boost amplitude of the photovoltaic DC-DC conversion module; and determining a voltage output by the switching device of the corresponding photovoltaic DC-DC conversion module according to the target duty cycle.

[0062] In the technical solution in the embodiments of the present disclosure, the working mode of the photovoltaic DC-DC conversion module can be flexibly controlled and adjusted, and the flexibility of the system is further improved.

[0063] According to an aspect of some other embodiments of the present disclosure, an electric energy transmission controller is provided, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute any of the above power transmission control methods based on instructions stored in the memory.

[0064] In the technical solution in the embodiments of the present disclosure, the voltage and current state of the two ends of the bidirectional buck-boost DC-DC conversion circuit can be detected in real time, the control strategy of the bidirectional buck-boost DC-DC conversion circuit is determined according to the real-time detection result, and the working mode adjustment of the bidirectional buck-boost DC-DC conversion circuit is realized through the control of the switching device in the bidirectional buck-boost DC-DC conversion circuit, so as to realize the improvement of the control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit, and further facilitate the improvement of the accuracy, flexibility and convenience of the electric energy bidirectional transmission of the circuits located on the two sides of the bidirectional buck-boost DC-DC conversion circuit.

[0065] According to an aspect of some other embodiments of the present disclosure, a non-transitory computer readable storage medium is provided, which stores computer program instructions, the instructions being executed by a processor to implement any of the above power transmission control methods.

[0066] In the technical solutions in the embodiments of the present disclosure, the voltage and current states at the two ends of the bidirectional buck-boost DC-DC conversion circuit can be detected in real time, the control strategy for the bidirectional buck-boost DC-DC conversion circuit is determined according to the real-time detection results, and the working mode of the bidirectional buck-boost DC-DC conversion circuit is adjusted through the control of the switching devices in the bidirectional buck-boost DC-DC conversion circuit, so that the control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit are improved, and the accuracy, flexibility and convenience of the circuits on the two sides of the bidirectional buck-boost DC-DC conversion circuit for bidirectional power transmission are improved.

[0067] According to an aspect of some other embodiments of the present disclosure, a computer program product is provided, which includes a computer program or instructions, and the computer program or instructions are executed by a processor to implement any of the power transmission control methods described above.

[0068] In the technical solutions in the embodiments of the present disclosure, the voltage and current states at the two ends of the bidirectional buck-boost DC-DC conversion circuit can be detected in real time, the control strategy for the bidirectional buck-boost DC-DC conversion circuit is determined according to the real-time detection results, and the working mode of the bidirectional buck-boost DC-DC conversion circuit is adjusted through the control of the switching devices in the bidirectional buck-boost DC-DC conversion circuit, so that the control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit are improved, and the accuracy, flexibility and convenience of the circuits on the two sides of the bidirectional buck-boost DC-DC conversion circuit for bidirectional power transmission are improved. BRIEF DESCRIPTION OF DRAWINGS

[0069] The accompanying drawings, which are included to provide a further understanding of the present disclosure, form a part of the present disclosure and illustrate certain illustrative embodiments of the present disclosure and its description, which do not constitute improper limitations on the present disclosure.

[0070] FIG. 1 is a schematic diagram of some embodiments of the power transmission control circuit of the present disclosure.

[0071] FIG. 2 is a schematic diagram of some embodiments of the connection relationship between the power transmission control circuit and the bidirectional buck-boost DC-DC conversion circuit of the present disclosure.

[0072] FIG. 3 is a schematic diagram of some embodiments of the application scenario of the power transmission control circuit of the present disclosure.

[0073] FIG. 4 is a schematic diagram of some other embodiments of the application scenario of the power transmission control circuit of the present disclosure.

[0074] FIG. 5 is a schematic diagram of some embodiments of the power transmission system of the present disclosure.

[0075] FIG. 6 is a schematic diagram of some embodiments of the power transmission system of the present disclosure.

[0076] FIG. 7 is a flow chart of some embodiments of the power-up process of the power transmission system of the present disclosure.

[0077] FIG. 8 is a schematic diagram of some embodiments of the photovoltaic DC-DC conversion module in the power transmission system of the present disclosure.

[0078] FIG. 9 is a flow chart of some embodiments of the power transmission control method of the present disclosure.

[0079] FIG. 10 is a schematic diagram of some embodiments of the power transmission controller of the present disclosure.

[0080] FIG. 11 is a schematic diagram of some other embodiments of the power transmission controller of the present disclosure. DETAILED DESCRIPTION

[0081] The technical solutions of the present disclosure are described in further detail below with reference to the accompanying drawings and embodiments.

[0082] In the intelligent light storage machine, the inverter module and the BMS module need to transmit energy in both directions, and need a suitable power electronic converter as an interface circuit. Such a power electronic converter should have four-quadrant working capability, i.e. it needs to be designed as a bidirectional buck-boost DC-DC converter. The working state of the bidirectional buck-boost DC-DC converter is adjusted under the control of the user.

[0083] The inventors have found that the control method in the related art is difficult to respond to the changes in the state of the power grid, the power storage and other related circuits in real time and flexibly, resulting in a mismatch between the transmission mode of the electric energy and the actual situation.

[0084] To solve the above problems, the present disclosure proposes a power transmission control circuit and control method and a power transmission system. The two ends of the bidirectional buck-boost DC-DC conversion circuit are detected in real time, and the working mode of the bidirectional buck-boost DC-DC conversion circuit is adjusted according to the real-time detection results, which is conducive to improving the accuracy, flexibility and convenience of the bidirectional power transmission of the circuits on both sides of the bidirectional buck-boost DC-DC conversion circuit.

[0085] A schematic diagram of some embodiments of the power transmission control circuit 10 of the present disclosure is shown in FIG. 1.

[0086] The detection module 11 can detect the voltage and current at the two ends of the bidirectional buck-boost DC-DC conversion circuit and obtain the detection results. The detection module 11 sends the detection results to the control module 12.

[0087] The control module 12 determines the target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection result. The control module 12 can be implemented in various ways, for example, by using an MCU (Microcontroller Unit).

[0088] In some embodiments, the control module 12 can have a correspondence relationship between the working mode of the bidirectional buck-boost DC-DC conversion circuit and the target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit. The control module 12 can first determine the target working mode according to the detection result, and then determine the target working state of each switching device according to the target working mode. In each working mode, the target working state of the switching device includes always on, always off, and periodic switching under the control of the driving voltage. In some embodiments, the above-mentioned working modes include: voltage transmission from the first end to the second end of the bidirectional buck-boost DC-DC conversion circuit, voltage transmission from the first end to the second end, voltage transmission from the second end to the first end, and voltage transmission from the second end to the first end. In such an electric energy transmission control circuit, the control module first determines the target working mode, and then determines the target working state according to the relationship between the target working mode and the working state of each switching device, thereby improving the accuracy of the control of the switching device and reducing the processing burden of the control module.

[0089] In some embodiments, the detection result includes the detection result of the voltage and the detection result of the current. The control module 12 can determine the current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the current, and can also determine the buck-boost mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the voltage. Further, the control module 12 determines the target working mode according to the current transmission direction and the buck-boost mode. In some embodiments, when the control module 12 determines that the current transmission direction of the bidirectional buck-boost DC-DC conversion circuit is from the first end to the second end, if it is determined that the current of the first end of the bidirectional buck-boost DC-DC conversion circuit is less than a predetermined current threshold, it is determined to switch to transmission from the second end to the first end. Further, if the voltage of the second end is lower than the target voltage (for example, the input voltage required by the first end), it is determined that the voltage needs to be boosted. Based on the above determination result, the target working mode is the voltage transmission mode from the second end to the first end.

[0090] In the technical solution in the embodiments of the present disclosure, the target working mode can be determined from the current transmission direction and the voltage buck-boost change, which not only makes the current transmission direction consistent with the current detection result, but also makes the output voltage consistent with the demand of the current receiving side, thereby improving the smoothness of the bus voltage and the delicacy and accuracy of the working mode adjustment, and being conducive to further improving the accuracy of the bidirectional electric energy transmission.

[0091] In some embodiments, the control module 12 can determine the duty cycle of the driving voltage according to the detection result, the driving voltage being a pulse voltage, and part of the switching devices in the bidirectional buck-boost DC-DC conversion circuit being periodically switched under the control of the driving voltage. By adjusting the duty cycle, the boost amplitude and the buck amplitude can be controlled, the flexibility of the buck-boost control is improved, and the control ability of the control circuit to the bidirectional buck-boost DC-DC conversion circuit is improved. In some embodiments, the control module can first determine the required buck-boost amplitude according to the electrical measurement result of the voltage, and then determine the duty cycle of the driving voltage according to the required buck-boost amplitude, so as to improve the matching degree of the output voltage and the demand of the receiving end, further improve the flexibility of the buck-boost regulation, and further improve the smoothness of the bus voltage.

[0092] The driving module 13 is connected with each switching device of the bidirectional buck-boost DC-DC conversion circuit, and outputs a voltage to the corresponding switching device according to the target working state under the control of the control module 12.

[0093] The electrical energy transmission control circuit in the above embodiments of the present disclosure can detect the voltage and current state of the two ends of the bidirectional buck-boost DC-DC conversion circuit in real time, determine the control strategy of the bidirectional buck-boost DC-DC conversion circuit according to the real-time detection result, and realize the working mode adjustment of the bidirectional buck-boost DC-DC conversion circuit by controlling the switching devices in the bidirectional buck-boost DC-DC conversion circuit, so as to improve the control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit, and further improve the accuracy, flexibility and convenience of the electrical energy bidirectional transmission of the circuits on both sides of the bidirectional buck-boost DC-DC conversion circuit.

[0094] In some embodiments, as shown in FIG. 1, the electrical energy transmission control circuit further comprises an auxiliary power supply module 14 connected with the two ends of the bidirectional buck-boost DC-DC conversion circuit and other parts of the electrical energy transmission control circuit, and can use the electrical energy from at least one end of the bidirectional buck-boost DC-DC conversion circuit to supply power to the detection module, the control module and the driving module.

[0095] In the technical solution in the embodiments of the present disclosure, the auxiliary power supply module can obtain electrical energy from the circuits connected to the two ends of the bidirectional buck-boost DC-DC conversion circuit, and when any circuit at any end has the ability to supply electrical energy, the auxiliary power supply module can supply power to other parts of the control circuit, thereby improving the stability of the operation of the control circuit; without using an external power supply, the burden of line deployment is reduced.

[0096] In some embodiments, the connection mode of the electrical energy transmission control circuit and the bidirectional buck-boost DC-DC conversion circuit is shown in FIG. 2. The connection relationship shown in FIG. 2 is a feasible embodiment of the present disclosure, and does not constitute an improper limitation on the present disclosure.

[0097] The bidirectional buck-boost DC-DC conversion circuit, as shown in the part between the two terminals in FIG. 2, includes four triodes (Q1-Q4), one inductor L1, and two capacitors C1 and C2. Among them, the triode is a switching device.

[0098] The bidirectional buck-boost DC-DC conversion circuit is a symmetrical Buck-Boost circuit, which can be converted in four working modes by controlling the working state of the triode, including left end side to right end side voltage boosting charging, left end side to right end side voltage reducing charging, right end side to left end side voltage boosting charging, and right end side to left end side voltage reducing charging.

[0099] Taking left end side to right end side charging as an example.

[0100] Left end side to right end side voltage reducing charging, the bidirectional buck-boost DC-DC conversion circuit switches to BUCK mode:

[0101] Q4 is always on, Q3 is always off, Q1 and Q2 are alternately turned on under the pulse control of the driving voltage, wherein in the case of Q1 being turned on and Q2 being turned off, L1 is charged in series; in the case of Q1 being turned off and Q2 being turned on, L1 is discharged in parallel.

[0102] Left end side to right end side voltage boosting charging, the bidirectional buck-boost DC-DC conversion circuit switches to BOOST mode:

[0103] Q1 is always on, Q2 is always off, Q3 and Q4 are alternately turned on under the pulse control of the driving voltage, wherein in the case of Q3 being turned off and Q4 being turned on, L1 is charged in series; in the case of Q3 being turned on and Q4 being turned off, L1 is discharged in parallel.

[0104] Adjusting the duty cycle is used to control the voltage within a certain range, but cannot control whether to switch to boost or reduce voltage.

[0105] Taking right end side to left end side charging as an example, based on the above description of left end side to right end side charging, Q1 and Q4 are interchanged, and Q2 and Q3 are interchanged.

[0106] In some embodiments, the detection module 11 of the electric energy transmission control circuit includes a voltage detection module 111 and a current detection module 112, in some embodiments, the voltage detection module and the current detection module can be arranged respectively at both ends of the bidirectional buck-boost DC-DC conversion circuit, or they can be combined.

[0107] In some embodiments, the detection module 11 can further include a temperature measurement module 113, which can detect the temperature of the switching device and send it to the control module 12. The control module 12 can cut off the current transmission in time in the case of determining that the temperature is abnormal (for example, higher than the predetermined upper limit of temperature), thereby reducing the probability of generating danger and improving the safety of the equipment.

[0108] In some embodiments, the control module 12 can accept upper layer control, for example, obtain upper layer control signaling through a CAN communication device, the control signaling can be used to adjust one or more of the control logic, parameters, target operating mode of the adjustment circuit of the control module, etc. In some embodiments, the control module 12, the detection module 11, the drive module 13 interact through CAN communication.

[0109] In some embodiments, as shown in FIG. 3, the electric energy transmission control circuit 10 can be used to control a bidirectional boost-buck DC-DC conversion circuit located between the power grid and the energy storage module. For example, the first end of the bidirectional boost-buck DC-DC conversion circuit 21 is connected to the inverter module 31 connected to the power grid, and the second end is connected to the energy storage module 50. The inverter module 31 and the bidirectional boost-buck DC-DC conversion circuit 21 are connected as a DC bus.

[0110] The control module 12 determines the target operating state to be power supply from the first end to the second end, i.e. the operating state of the switching device in the operating mode of the switching device in the target operating state of power supply from the first end to the second end, when it is determined according to the detection result that there is power supply on the power grid side, i.e. the power grid is online.

[0111] The control module 12 determines the target operating state to be power supply from the second end to the first end, i.e. the operating state of the switching device in the operating mode of the switching device in the target operating state of power supply from the second end to the first end, when it is determined according to the detection result that there is no power supply on the power grid side, i.e. the power grid is offline.

[0112] Further, the electric energy transmission control circuit 10 can determine the boost mode or the buck mode according to the voltage conditions of the first end and the second end.

[0113] Such an electric energy transmission control circuit can automatically adjust the operating mode of the bidirectional boost-buck DC-DC conversion circuit in real time according to whether there is power supply on the power grid side when the bidirectional boost-buck DC-DC conversion circuit is used as the transmission circuit between the power grid and the energy storage module, while realizing the energy storage of the energy storage module using the power grid electric energy, and also being able to use the energy storage to supply power to the AC equipment close to the power grid side, thereby improving the operation stability of the power network.

[0114] In some embodiments, as shown in FIG. 3, the electric energy transmission control circuit 10 can be used to control a bidirectional boost-buck DC-DC conversion circuit located between the photovoltaic circuit and the energy storage module. For example, the first end of the bidirectional boost-buck DC-DC conversion circuit is connected to the photovoltaic DC-DC module 41 connected to the photovoltaic circuit, and the second end is connected to the energy storage module 50.

[0115] The control module 12 determines that the target working state is power supply from the first end to the second end when it is determined according to the detection result that the photovoltaic circuit side has power supply, and determines that the target working state is the working state of the switching device in the working mode of power supply from the first end to the second end.

[0116] Such an electric energy transmission control circuit can flexibly switch whether the photovoltaic power generation is stored in the energy storage module when the bidirectional buck-boost DC-DC conversion circuit is used as the transmission circuit between the photovoltaic power generation device and the energy storage module, improve the flexibility of photovoltaic power generation storage, and improve the control ability of the control circuit to the electric energy flow direction in the system.

[0117] In some embodiments, as shown in FIG. 3, the electric energy transmission control circuit 10 can be used to control a bidirectional buck-boost DC-DC conversion circuit between a DC bus and an energy storage module, wherein the bidirectional inverter connected to the power grid and the photovoltaic DC-DC module are both connected to the DC bus. For example, the second end of the bidirectional buck-boost DC-DC conversion circuit is connected to the energy storage module, and the inverter module connected to the power grid and the photovoltaic DC-DC module connected to the photovoltaic circuit are connected in parallel at the first end of the bidirectional buck-boost DC-DC conversion circuit.

[0118] The control module 12 can determine that the target working state is power supply from the first end to the second end when it is determined according to the detection result that the power grid has power supply or the photovoltaic circuit side has power supply, and determine that the target working state is the working state of the switching device in the working mode of power supply from the first end to the second end.

[0119] The control module 12 can determine that the target working state is power supply from the second end to the first end when it is determined according to the detection result that the power grid side has no power supply and the energy storage module has power supply, and determine that the target working state is the working state of the switching device in the working mode of power supply from the second end to the first end.

[0120] Such an electric energy transmission control circuit can flexibly control the transmission of electric energy between the power grid and the energy storage module, and between the photovoltaic circuit and the energy storage module, and determine the power supply of the power grid, the photovoltaic circuit, and the energy storage module in real time according to the detection result and adjust in time, thereby improving the utilization rate and storage efficiency of electric energy, and improving the operation stability of the equipment operated by the power grid.

[0121] In some embodiments, as shown in FIG. 4, the electric energy transmission control circuit 10 can be used to control a bidirectional buck-boost DC-DC conversion circuit between energy storage units, and each energy storage unit can be a battery or a battery pack. For example, the first end of the bidirectional buck-boost DC-DC conversion circuit 22 is connected to the first energy storage unit 51, and the second end is connected to the second energy storage unit 53.

[0122] The control module 12 determines the target working state of the switching device as the working state in the working mode of supplying power from the first terminal to the second terminal when it is determined to supply power from the first energy storage unit to the second energy storage unit.

[0123] The control module 12 determines the target working state of the switching device as the working state in the working mode of supplying power from the second terminal to the first terminal when it is determined to supply power from the second energy storage unit to the first energy storage unit.

[0124] In some embodiments, the demand of power transmission between the energy storage units can be determined according to the amount of electricity between the energy storage units or the upper-layer configuration.

[0125] Such a power transmission control circuit can control the current conduction direction between the energy storage units, so that the power can be flexibly transferred between the energy storage units, and the flexibility of energy storage control of the energy storage units is improved.

[0126] In some embodiments, as shown in the application scenario of FIG. 4, the control module 12 can further determine the boost-buck mode and the boost-buck amplitude according to the voltage difference between the first energy storage unit and the second energy storage unit, and then determine the working state of the switching device in the corresponding working mode in combination with the determined current transmission direction, and determine the duty cycle of the driving voltage according to the boost-buck amplitude.

[0127] Such a power transmission control circuit can further determine whether to use the boost mode or the buck mode after determining the flow direction of the power between the energy storage units, so as to determine the required working state of the switching device; on this basis, the boost-buck amplitude is controlled by adjusting the duty cycle, so as to facilitate the energy exchange between the energy storage units of different voltage levels, and further improve the flexibility of energy storage control of the energy storage units.

[0128] The present disclosure also proposes a power transmission system. The schematic diagram of some embodiments of the power transmission system of the present disclosure is shown in FIG. 5, which includes a power transmission control circuit 10 and a bidirectional boost-buck DC-DC conversion circuit 20.

[0129] The power transmission control circuit 10 is any one of the power transmission control circuits proposed by the present disclosure mentioned above. The bidirectional boost-buck DC-DC conversion circuit 20 is any one of the bidirectional boost-buck DC-DC conversion circuits mentioned above. In some embodiments, the internal linkage relationship of the power transmission system can be as shown in FIG. 2.

[0130] In some embodiments, as shown in FIG. 2, the bidirectional boost-buck DC-DC conversion circuit includes at least two safety tubes S1 and S2 located at both ends of the bidirectional boost-buck DC-DC conversion circuit, which can prevent short circuit caused by sudden change of current on either side, and improve the safety of the circuit.

[0131] In some embodiments, as shown in FIG. 2, the bidirectional buck-boost DC-DC conversion circuit includes at least two sampling resistors located at both ends of the bidirectional buck-boost DC-DC conversion circuit, so that the power transmission control circuit 10 can obtain detection results according to the resistance values of the sampling resistors and the currents passing through the sampling resistors, and improve the accuracy of detection.

[0132] In the power transmission system of the embodiments of the present disclosure, the power transmission control circuit can detect the voltage and current state at both ends of the bidirectional buck-boost DC-DC conversion circuit in real time, determine the control strategy for the bidirectional buck-boost DC-DC conversion circuit according to the real-time detection results, and adjust the working mode of the bidirectional buck-boost DC-DC conversion circuit by controlling the switching devices in the bidirectional buck-boost DC-DC conversion circuit, thereby improving the control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit, and further improving the accuracy, flexibility and convenience of the circuits located at both sides of the bidirectional buck-boost DC-DC conversion circuit for bidirectional power transmission.

[0133] In some embodiments, as shown in FIG. 3 or FIG. 6, the bidirectional buck-boost DC-DC conversion circuit includes a first bidirectional buck-boost DC-DC conversion circuit 21 located between the power grid and the power storage module, which can perform voltage adjustment and power transmission between the power grid and the power storage module.

[0134] In the power transmission system of the embodiments of the present disclosure, the bidirectional buck-boost DC-DC conversion circuit controlled by the power transmission control circuit can be deployed between the power grid and the power storage module, so that the working mode of the bidirectional buck-boost DC-DC conversion circuit can be automatically adjusted in real time according to whether there is power supply on the power grid side, which can not only store energy in the power storage module by using the power grid power, but also supply power to the AC equipment close to the power grid side by using the stored energy, thereby improving the operation stability of the power network.

[0135] In some embodiments, as shown in FIG. 3 or FIG. 6, the first bidirectional buck-boost DC-DC conversion circuit 21 can also perform voltage adjustment and power transmission between the photovoltaic circuit and the power storage module.

[0136] In the power transmission system of the embodiments of the present disclosure, the bidirectional buck-boost DC-DC conversion circuit controlled by the power transmission control circuit can be deployed between the photovoltaic power generation device and the power storage module, so that the photovoltaic power generation can be flexibly switched to store power in the power storage module, thereby improving the flexibility of photovoltaic power generation storage and the control ability of the control circuit to the power flow in the system.

[0137] In some embodiments, as shown in FIG. 4 or FIG. 6, the bidirectional buck-boost DC-DC conversion circuit includes a second bidirectional buck-boost DC-DC conversion circuit 22 between the two energy storage units, capable of voltage regulation and power transmission between the two connected energy storage units. Since the rated output voltage of the battery is high or low, and the stored energy is more or less, a suitable power electronic converter is used as an interface circuit to realize energy exchange between batteries of different voltage levels, which can improve the flexibility of energy use and storage. In the power transmission system of the embodiments of the present disclosure, the bidirectional buck-boost DC-DC conversion circuit controlled by the power transmission control circuit can be deployed between the energy storage units to control the current conduction direction between the energy storage units, so that the power can be flexibly transferred between the energy storage units, and the flexibility of energy storage control of the energy storage units is improved.

[0138] In some embodiments, as shown in FIG. 6, the power transmission system further includes an inverter module 31 between the power grid and the first bidirectional buck-boost DC-DC conversion circuit 21. The inverter module 31 is a bidirectional inverter capable of converting alternating current of a first voltage from the power grid into direct current of a second voltage to be delivered to the first end of the first bidirectional buck-boost DC-DC conversion circuit, and also capable of converting direct current of the second voltage from the first bidirectional buck-boost DC-DC conversion circuit into alternating current of the first voltage to be delivered to an alternating current appliance for use.

[0139] In the power transmission system of the embodiments of the present disclosure, the inverter module can realize AC-DC conversion from the power grid to the DC bus and DC-AC conversion from the DC bus to the power grid, which facilitates charging of the energy storage module while enabling the alternating current appliance on the power grid side to work with stored energy, thereby improving the stability of the appliance operation.

[0140] In some embodiments, as shown in FIG. 6, the power transmission system further includes a photovoltaic DC-DC conversion module 41 between the photovoltaic interface 42 connected to the photovoltaic panel 43 and the first bidirectional buck-boost DC-DC conversion circuit 21, capable of converting direct current of a third voltage from the photovoltaic interface into direct current of a fourth voltage to be delivered to the first end of the first bidirectional buck-boost DC-DC conversion circuit. In some embodiments, the photovoltaic DC-DC conversion module includes a transistor intercepting current from the first end of the first bidirectional buck-boost DC-DC conversion circuit to the photovoltaic interface, avoiding current backflow and improving the safety of the photovoltaic circuit.

[0141] In some embodiments, as shown in FIG. 6, the overall topology of the intelligent light storage machine. In the grid-connected state (connected to the power grid), the intelligent light storage machine converts 220V AC power into 48V bus voltage through the inverter module, and then transmits the power to the 48V DC electrical appliance, or through the energy storage DC-DC module (in the disclosure, the voltage conversion is realized by the bidirectional buck-boost DC-DC conversion circuit in FIG. 6), and then stores the voltage required by the BMS (Battery Management System, battery management system) in the battery. In the off-grid state (disconnected from the power grid), the intelligent light storage machine uses the power stored in the battery, converts the battery voltage through the energy storage DC-DC module into the voltage required by the inverter module, and then converts it into 220V AC voltage through the inverter to power the AC electrical appliance (such as household appliances, etc.). When the photovoltaic panel is working, the photovoltaic panel voltage is converted into 48V bus voltage through the photovoltaic DC-DC module, and then converted into the voltage required by the BMS through the energy storage DC-DC module, and stored in the battery of the battery storage module. When the battery is full, the energy of the photovoltaic panel is converted into 220V voltage through the bidirectional inverter module and fed back to the power grid.

[0142] Taking the overall topology environment of the intelligent light storage machine shown in FIG. 6 as an example, in the bidirectional buck-boost DC-DC conversion circuit shown in FIG. 2, Q1, Q2, Q3, and Q4 are N-level or P-level field effect transistors. Considering the cost, N-type field effect transistors can be selected for use. In some embodiments, L1 is a 40uH inductor, and when the current is 28A, the inductance value decreases to 33uH. The above inductance and current settings are suitable for the application environment of the intelligent light storage machine. In some embodiments, S1 and S2 are 100V / 30A safety tubes, which match the voltage and current conditions in the intelligent light storage machine, can play a safety protection role while avoiding frequent disconnection affecting use. The filter capacitors C1 and C2 are only identified as filter capacitors, and do not represent that only one filter capacitor is included at the corresponding position. The number and size of the capacitors can be calculated and adjusted based on the understanding of the filter circuit by those skilled in the art according to the specific circumstances, which will not be described here. The sampling resistors R1 and R2 are arranged at both ends of the bidirectional buck-boost DC-DC conversion circuit. After the current passes through the sampling resistor, the current is sampled by the detection module (such as the current detection module). In some embodiments, the resistance value is changed according to the needs of other modules to adjust the size of the input and output current, so as to facilitate the overall matching of the intelligent light storage machine. In the power transmission system of the embodiment of the disclosure, the photovoltaic DC-DC conversion module can convert the voltage of the power from the photovoltaic panel, which is convenient for grid connection to the DC bus; the transistor avoids the transmission of the power of the battery storage module to the photovoltaic panel, thereby improving the safety of the photovoltaic circuit.

[0143] In some embodiments, the output voltage of the inverter module 31 of the smart light storage device is between 35-60V, and the output voltage of the storage module 50 is between 35-60V. The bi-directional DC-DC converter 21 performs step-up and step-down processing, so that the voltage at the output end of the bi-directional DC-DC converter 21 is 48V, thereby improving the stability of the output voltage from the storage module to the DC bus and from the power grid to the storage module.

[0144] In some embodiments, the output voltage of the photovoltaic panel 43 through the photovoltaic interface 42 is between 15-60V, and the photovoltaic DC-DC module 41 performs step-up and step-down processing, so that the output voltage of the photovoltaic DC-DC module 41 is 48V, thereby improving the stability of the output voltage from the photovoltaic module to the DC bus.

[0145] In some embodiments, based on the circuit shown in FIG. 6, a flowchart of some embodiments of the power-on process of the power transmission system of the present disclosure is shown in FIG. 7. The judgment logic shown below is only an example and does not constitute an improper limitation on the present disclosure. The judgment order of the power grid, the storage module, and the photovoltaic circuit can be adjusted according to actual needs.

[0146] In step 701, the auxiliary power supply module of the power transmission control circuit first determines whether the power grid has power supply capability. If the power grid has power supply capability, step 702 is performed; if the power grid currently does not have power supply capability, step 703 is performed.

[0147] In step 702, it is determined to obtain power from the inverter module, and step 707 is performed.

[0148] In step 703, it is determined whether the storage module has power supply capability. If the storage module has power supply capability, step 704 is performed; if the storage module does not have power supply capability, step 705 is performed.

[0149] In step 704, it is determined to obtain power from the storage module, and step 707 is performed.

[0150] In step 705, it is determined whether the photovoltaic circuit has power supply capability. If the photovoltaic circuit has power supply capability, step 706 is performed; if the photovoltaic circuit does not have power supply capability, the flow ends or returns to step 701 for re-execution. In some embodiments, the above-mentioned judgment logic can be realized by setting the connection relationship between the auxiliary power supply module and other modules, thereby reducing the use amount of logic processing devices and reducing the cost of equipment.

[0151] In step 706, it is determined to obtain power from the photovoltaic DC-DC module, and step 707 is performed.

[0152] In step 707, the auxiliary power supply module obtains power.

[0153] In step 708, the acquired electric energy is delivered to other parts of the electric energy transmission control circuit, such as the detection module, the control module, and the driving module, to trigger the electric energy transmission control circuit to operate.

[0154] The electric energy transmission system of the present disclosure can acquire electric energy from multiple circuits, and when any circuit at either end has the ability to supply electric energy, the auxiliary power module can supply power to other parts of the control circuit, thereby improving the stability of the control circuit in operation. The use of an external power supply is not required, thereby reducing the burden of line deployment.

[0155] In some embodiments, the photovoltaic DC-DC conversion module is a four-switch buck-boost circuit. For example, as shown in FIG. 8, the photovoltaic DC-DC conversion module includes four transistors (Q5-Q8), one inductor L2, and two capacitors C3 and C4. This circuit is similar to the bidirectional buck-boost DC-DC conversion circuit in the above-described embodiments, but a diode D1 is provided, which can intercept current from the direction of the DC bus. The four-switch buck-boost circuit can avoid changing the polarity of the current, thereby improving the matching degree with the entire machine.

[0156] In some embodiments, each switching device (such as Q5-Q8) of the photovoltaic DC-DC conversion module is connected to the electric energy transmission control circuit. The electric energy transmission control circuit 10 can detect the voltage value of the end (left side in FIG. 8) of the photovoltaic DC-DC conversion module connected to the photovoltaic interface, and determine the buck-boost mode and the buck-boost amplitude of the photovoltaic DC-DC conversion module according to the voltage value and the target voltage (such as the DC bus voltage) of the photovoltaic DC-DC conversion. Further, according to the buck-boost mode, the target working state of the switching device of the photovoltaic DC-DC conversion module is determined to be the working state corresponding to the buck-boost mode. In addition, the electric energy transmission control circuit 10 can also determine the target duty cycle according to the buck-boost amplitude of the photovoltaic DC-DC conversion module; and output a voltage to the corresponding switching device of the photovoltaic DC-DC conversion module according to the target duty cycle.

[0157] In the electric energy transmission system of the embodiments of the present disclosure, the working mode of the photovoltaic DC-DC conversion module can also be controlled and adjusted by the electric energy transmission control circuit, thereby further improving the flexibility of the system.

[0158] In some embodiments, as shown in FIG. 8, the photovoltaic DC-DC conversion module further includes a third safety tube R3 located at the end of the photovoltaic DC-DC conversion module connected to the photovoltaic interface, which can avoid short circuit caused by sudden change of current on the photovoltaic circuit side, thereby improving the safety of the circuit. Considering that the diode D1 has been provided, a transistor does not need to be provided on the DC bus side of the photovoltaic DC-DC conversion module, thereby avoiding additional costs.

[0159] A flowchart of some embodiments of the power transmission control method of the present disclosure is shown in FIG. 9.

[0160] In step 901, the detection results of the voltage and current at both ends of the bidirectional buck-boost DC-DC conversion circuit are obtained.

[0161] In step 902, the target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit is determined according to the detection results.

[0162] In some embodiments, the target working mode is first determined according to the detection results, and then the target working state of each switching device is determined according to the target working mode. In each working mode, the target working state of the switching device includes always on, always off, and periodic switching under the control of the driving voltage. In some embodiments, the above-mentioned working modes include: boosting transmission from the first end to the second end of the bidirectional buck-boost DC-DC conversion circuit, bucking transmission from the first end to the second end, boosting transmission from the second end to the first end, and bucking transmission from the second end to the first end. By such a method, the target working mode can be determined first, and then the target working state can be determined according to the relationship between the target working mode and the working state of each switching device, thereby improving the accuracy of the control of the switching device and reducing the processing burden.

[0163] In some embodiments, the current transmission direction of the bidirectional buck-boost DC-DC conversion circuit is determined according to the detection results of the current, and the buck-boost mode of the bidirectional buck-boost DC-DC conversion circuit is determined according to the detection results of the voltage. Then the target working mode is determined according to the current transmission direction and the buck-boost mode. By such a method, the target working mode can be determined from the current transmission direction and the change of the voltage, and the output voltage is also made to meet the needs of the current receiving side when the current transmission direction meets the current detection results, thereby improving the smoothness of the bus voltage, the delicacy and accuracy of the working mode adjustment, and further improving the accuracy of the bidirectional power transmission.

[0164] In some embodiments, the duty cycle of the driving voltage is determined according to the detection results, for example, the required buck-boost amplitude is determined according to the voltage detection results, and then the duty cycle of the driving voltage is determined according to the required buck-boost amplitude, thereby improving the matching degree of the output voltage and the needs of the receiving end, improving the flexibility of the buck-boost control, and improving the control ability of the control circuit to the bidirectional buck-boost DC-DC conversion circuit.

[0165] In step 903, the voltage output to the corresponding switching device is determined according to the target working state, including controlling the switching device to be on or off, and periodically switching under the driving of the driving voltage.

[0166] In the power transmission control method in the embodiments of the present disclosure, the control strategy of the bidirectional buck-boost DC-DC conversion circuit can be determined according to the real-time detection result of the bidirectional buck-boost DC-DC conversion circuit, and the working mode of the bidirectional buck-boost DC-DC conversion circuit is adjusted by controlling the switching device in the bidirectional buck-boost DC-DC conversion circuit, so as to improve the control flexibility and real-time performance of the bidirectional buck-boost DC-DC conversion circuit, and further improve the accuracy, flexibility and convenience of the power bidirectional transmission of the circuits on both sides of the bidirectional buck-boost DC-DC conversion circuit.

[0167] In some embodiments, the power transmission control method of the present disclosure is also used in the scene of determining the current transmission direction based on demand, for example, controlling the bidirectional buck-boost DC-DC conversion circuit between the energy storage units. The power transmission control method comprises: determining the current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the demand of the current transmission direction, and determining the buck-boost mode and the buck-boost amplitude according to the voltage difference between the two ends of the bidirectional buck-boost DC-DC conversion circuit; determining the target working state as the working state of the switching device corresponding to the buck-boost mode in the case of the determined current transmission direction according to the buck-boost mode; and determining the duty cycle of the driving voltage according to the buck-boost amplitude.

[0168] In the technical solution in the embodiments of the present disclosure, after the flow direction of the power is determined, it is further determined whether to use the boost mode or the buck mode, so as to determine the required working state of the switching device; on this basis, the buck-boost amplitude is controlled by adjusting the duty cycle, and the flexibility of the control is improved. In the case of being applied to control the circuit between the energy storage units, the energy exchange between the batteries with different voltage levels is facilitated, and the flexibility of the energy storage control of the energy storage units is further improved.

[0169] In some embodiments, the power transmission control method of the present disclosure is also used to control a photovoltaic DC-DC conversion module of a photovoltaic circuit, for example, the photovoltaic DC-DC conversion module is located between a photovoltaic interface connected to a photovoltaic panel and the first bidirectional buck-boost DC-DC conversion circuit, and is capable of converting direct current of a third voltage from the photovoltaic interface into direct current of a fourth voltage. Based on the power transmission control method of the present disclosure, the voltage value of one end of the photovoltaic DC-DC conversion module connected to the photovoltaic interface is first acquired, and then the voltage value and the target voltage of the photovoltaic DC-DC conversion are used to determine the buck-boost mode and the buck-boost amplitude of the photovoltaic DC-DC conversion module. According to the buck-boost mode, the target working state of the switching device of the photovoltaic DC-DC conversion module is determined to be: the current direction is from the photovoltaic interface to the first bidirectional buck-boost DC-DC conversion circuit, and the working state conforms to the corresponding buck-boost mode. Further, the target duty cycle is determined according to the buck-boost amplitude of the photovoltaic DC-DC conversion module. The voltage output by the switching device of the corresponding photovoltaic DC-DC conversion module is determined according to the target duty cycle.

[0170] In the technical solution in the embodiments of the present disclosure, the working mode of the photovoltaic DC-DC conversion module can be flexibly controlled and adjusted, and the flexibility of the system is further improved.

[0171] The power transmission control method of the present disclosure can be applied to any one of the power transmission control circuits in the above or can be applied to the control module 12 of the power transmission control circuit.

[0172] The power transmission controller of the present disclosure can be any one of the control modules 12 in the above. The structural schematic diagram of some embodiments of the power transmission controller is shown in FIG. 10. The power transmission controller includes a memory 1001 and a processor 1002. The memory 1001 can be a disk, a flash memory or any other non-volatile storage medium. The memory is used to store the instructions in the corresponding embodiments of the power transmission control method in the above. The processor 1002 is coupled to the memory 1001 and can be implemented as one or more integrated circuits, such as a microprocessor or a microcontroller. The processor 1002 is used to execute the instructions stored in the memory, and can improve the accuracy, flexibility and convenience of the bidirectional power transmission.

[0173] In some embodiments, as shown in FIG. 11, the power transmission controller 1100 includes a memory 1101 and a processor 1102. The processor 1102 is coupled to the memory 1101 through a BUS bus 1103. The power transmission controller 1100 can also be connected to an external storage device 1105 through a storage interface 1104 to call external data, and can also be connected to a network or another computer system (not shown) through a network interface 1106. Details are not described here.

[0174] In the embodiment, the data instruction is stored in the memory, and the processor processes the data instruction, so that the accuracy, flexibility and convenience of the bidirectional power transmission are improved.

[0175] In some other embodiments, a computer readable storage medium has stored thereon computer program instructions which, when executed by a processor, implement the steps of the method in the corresponding embodiment of the power transmission control method. Those skilled in the art should understand that the embodiments of the disclosure can be provided as a method, device or computer program product. Therefore, the disclosure can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Moreover, the disclosure can take the form of a computer program product implemented on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) containing computer-usable program code.

[0176] The above description of the various embodiments tends to emphasize differences between the various embodiments, and the same or similar parts can be referred to each other, and for brevity, will not be described herein.

[0177] The disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the disclosure. It should be understood that each flow and / or block in the flowcharts and / or block diagrams and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flows of the flowcharts and / or one or more blocks of the block diagrams.

[0178] These computer program instructions can also be stored in a computer readable memory that can cause the computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce a product including instruction devices, which implement the functions specified in one or more flows of the flowcharts and / or one or more blocks of the block diagrams.

[0179] These computer program instructions can also be loaded into a computer or other programmable data processing device, so that a series of operation steps are performed on the computer or other programmable device to produce a computer implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows of the flowcharts and / or one or more blocks of the block diagrams.

[0180] So far, the present disclosure has been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein according to the above description.

[0181] The method and device of the present disclosure can be implemented in many ways. For example, the method and device of the present disclosure can be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the method is only for illustration, and the steps of the method of the present disclosure are not limited to the above specifically described order, unless otherwise specifically described. In addition, in some embodiments, the present disclosure can also be implemented as programs recorded in recording media, which include machine-readable instructions for implementing the method according to the present disclosure. Therefore, the present disclosure also covers the recording media storing the programs for executing the method according to the present disclosure.

[0182] It should be noted that the terms "first", "second", and the like in the description and claims of the present disclosure and the accompanying drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0183] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present disclosure and not to limit them; although the present disclosure has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present disclosure can still be modified or some technical features can be replaced by equivalents; without departing from the spirit of the technical solutions of the present disclosure, they should all be covered in the technical solution range of the present disclosure claimed.

Claims

1. An electric energy transmission control circuit, comprising: a detection module configured to detect voltage and current across a bidirectional buck-boost DC-DC conversion circuit, and obtain detection results; a control module configured to determine target operating states of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection results; and a driving module configured to output a driving voltage to a corresponding switching device according to the target operating states. The control module is configured to:

2. The electrical energy transfer control circuit of claim 1, wherein, determine a target operating mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection results; determine the target operating states of the each switching device according to the target operating mode, wherein the target operating states include always-on, always-off, and periodic switching under control of the driving voltage. The control module is configured to:

3. The electrical energy transfer control circuit of claim 2, wherein, determine a current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the detection results of current; determine a buck-boost mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection results of voltage; determine the target operating mode according to the current transmission direction and the buck-boost mode.

4. The electric energy transmission control circuit of any one of claims 1-3, wherein: the control module is further configured to determine a duty cycle of the driving voltage according to the detection results; and the driving module is configured to output the driving voltage to two of the switching devices according to the duty cycle of the driving voltage. The control module is configured to:

5. The electrical energy transfer control circuit of claim 4, wherein, determine a buck-boost amplitude according to the detection results of voltage; determine the duty cycle of the driving voltage according to the buck-boost amplitude. A first end of the bidirectional buck-boost DC-DC conversion circuit is connected to an inverter module connected to a power grid, and a second end is connected to an energy storage module, wherein:

6. The electric energy transfer control circuit according to any one of claims 1 to 5, wherein the control module is configured to perform at least one of: determining the target operating states of the switching devices in a mode of supplying power from the first end to the second end, when it is determined according to the detection results that the power grid side has power supply; and determining the target operating states of the switching devices in a mode of supplying power from the second end to the first end, when it is determined according to the detection results that the power grid side has no power supply. A first end of the bidirectional buck-boost DC-DC conversion circuit is connected to a photovoltaic DC-DC module connected to a photovoltaic circuit, and a second end is connected to an energy storage module, wherein:

7. The electric energy transfer control circuit according to any one of claims 1 to 5, wherein the control module is configured to: determine the target operating states of the switching devices in a mode of supplying power from the first end to the second end, when it is determined according to the detection results that the photovoltaic circuit side has power supply. A second end of the bidirectional buck-boost DC-DC conversion circuit is connected to an energy storage module, and an inverter module connected to a power grid and a photovoltaic DC-DC module connected to a photovoltaic circuit are connected in parallel at a first end of the bidirectional buck-boost DC-DC conversion circuit, wherein:

8. The electric energy transfer control circuit according to any one of claims 1 to 5, wherein the control module is configured to perform at least one of: ​ determining the target working state of the switching device as the working state of the switching device in the working mode of supplying power from the first end to the second end, when it is determined according to the detection result that the power supply exists on the grid side or the power supply exists on the photovoltaic circuit side; determining the target working state of the switching device as the working state of the switching device in the working mode of supplying power from the second end to the first end, when it is determined according to the detection result that the power supply does not exist on the grid side and the power supply exists on the power storage module.

9. The electric energy transfer control circuit according to any one of claims 1 to 5, wherein The first end of the bidirectional buck-boost DC-DC conversion circuit is connected with the first power storage unit, and the second end is connected with the second power storage unit, wherein, The control module is further configured to: determining the target working state of the switching device as the working state of the switching device in the working mode of supplying power from the first end to the second end, when it is determined that power is supplied from the first power storage unit to the second power storage unit; determining the target working state of the switching device as the working state of the switching device in the working mode of supplying power from the second end to the first end, when it is determined that power is supplied from the second power storage unit to the first power storage unit.

10. The electrical energy transfer control circuit of claim 9, wherein, The control module is further configured to: determining the buck-boost mode and the buck-boost amplitude according to the voltage difference between the first power storage unit and the second power storage unit; determining the working state of the switching device in the corresponding buck-boost mode according to the target working state as the current transmission direction determined according to the buck-boost mode; determining the duty cycle of the driving voltage according to the buck-boost amplitude.

11. The power transmission control circuit according to any one of claims 1-10, further comprising: an auxiliary power supply module connected with both ends of the bidirectional buck-boost DC-DC conversion circuit, and the detection module, the control module and the driving module, and configured to supply power to the detection module, the control module and the driving module by using the power from at least one end of the bidirectional buck-boost DC-DC conversion circuit.

12. The electric energy transfer control circuit of any one of claims 1-11, wherein, The detection module is further configured to detect the temperature of the switching device of the bidirectional buck-boost DC-DC conversion circuit; The control module is further configured to determine to disconnect the bidirectional buck-boost DC-DC conversion circuit when the temperature exceeds a predetermined temperature range.

13. A power transmission system, comprising: the power transmission control circuit according to any one of claims 1-12, configured to control the target working state of each switching device in the bidirectional buck-boost DC-DC conversion circuit; and the bidirectional buck-boost DC-DC conversion circuit comprising at least four switching devices, each of which is connected with the power transmission control circuit. The bidirectional buck-boost DC-DC conversion circuit comprises a first bidirectional buck-boost DC-DC conversion circuit between the grid and the power storage module, and is configured to perform voltage buck-boost regulation and power transmission between the grid and the power storage module.

14. The electric energy transfer system of claim 13, wherein, The first bidirectional buck-boost DC-DC conversion circuit is further configured to perform voltage buck-boost regulation and power transmission between the photovoltaic circuit and the power storage module.

15. The electric energy transfer system of claim 14, wherein, ​ 16. An electric power transfer system according to any one of claims 13 to 15, wherein, The bidirectional buck-boost DC-DC conversion circuit includes a second bidirectional buck-boost DC-DC conversion circuit between two power storage units, configured to perform voltage buck-boost regulation and power transmission between the two connected power storage units.

17. The power transmission system of claim 14 or 15, further comprising: an inverter module between the power grid and the first bidirectional buck-boost DC-DC conversion circuit, configured to perform at least one of: convert alternating current of a first voltage from the power grid into direct current of a second voltage for delivery to the first end of the first bidirectional buck-boost DC-DC conversion circuit; convert direct current of the second voltage from the first bidirectional buck-boost DC-DC conversion circuit into alternating current of the first voltage for delivery to an alternating current appliance.

18. The power transmission system of claim 15, further comprising: a photovoltaic DC-DC conversion module between a photovoltaic interface connected to a photovoltaic panel and the first bidirectional buck-boost DC-DC conversion circuit, configured to convert direct current of a third voltage from the photovoltaic interface into direct current of a fourth voltage for delivery to the first end of the first bidirectional buck-boost DC-DC conversion circuit, wherein the photovoltaic DC-DC conversion module includes a transistor to intercept current from the first end of the first bidirectional buck-boost DC-DC conversion circuit to the photovoltaic interface.

19. The electric energy transfer system of claim 18, wherein, The photovoltaic DC-DC conversion module is a four-switch buck-boost circuit.

20. The electric energy transfer system of claim 19, wherein, Each switching device of the photovoltaic DC-DC conversion module is connected to the power transmission control circuit. The power transmission control circuit is further configured to: detect a voltage value of the end of the photovoltaic DC-DC conversion module connected to the photovoltaic interface, and determine a buck-boost mode and a buck-boost amplitude of the photovoltaic DC-DC conversion module according to the voltage value and a target voltage of the photovoltaic DC-DC conversion; determine a target operating state of the switching device of the photovoltaic DC-DC conversion module according to the buck-boost mode, which is an operating state conforming to the corresponding buck-boost mode when the current direction is from the photovoltaic interface to the first bidirectional buck-boost DC-DC conversion circuit; determine a target duty cycle according to the buck-boost amplitude of the photovoltaic DC-DC conversion module; output a voltage to the corresponding switching device of the photovoltaic DC-DC conversion module according to the target duty cycle.

21. An electric power transfer system according to any one of claims 13 to 20, wherein, The bidirectional buck-boost DC-DC conversion circuit includes at least one of: at least two safety tubes at both ends of the bidirectional buck-boost DC-DC conversion circuit; at least two sampling resistors at both ends of the bidirectional buck-boost DC-DC conversion circuit, wherein the power transmission control circuit is configured to obtain a detection result according to the resistance values of the sampling resistors and the currents passing through the sampling resistors.

22. An electric power transfer system according to any one of claims 18 to 20, wherein, The photovoltaic DC-DC conversion module further includes a third safety tube at the end of the photovoltaic DC-DC conversion module connected to the photovoltaic interface.

23. A power transmission control method, comprising: obtaining detection results of voltage and current at both ends of a bidirectional buck-boost DC-DC conversion circuit; determining a target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection result; and determining a voltage output to the corresponding switching device according to the target working state.

24. The electric energy transfer control method of claim 23, wherein, The determining a target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection result comprises: determining a target working mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection result; determining the target working state of the each switching device according to the target working mode, wherein the target working state comprises always-on, always-off and periodic switching under the control of a driving voltage.

25. The electric energy transfer control method of claim 24, wherein, The determining a target working state of each switching device of the bidirectional buck-boost DC-DC conversion circuit according to the detection result comprises: determining a current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the current; determining a buck-boost mode of the bidirectional buck-boost DC-DC conversion circuit according to the detection result of the voltage; determining the target working mode according to the current transmission direction and the buck-boost mode.

26. A power transfer control method according to any one of claims 23 to 25, further comprising: determining a duty cycle of the driving voltage according to the detection result; The determining a voltage output to the corresponding switching device according to the target working state comprises: determining the driving voltage output to the two switching devices according to the duty cycle of the driving voltage.

27. The electric energy transmission control method of any one of claims 23-26, further comprising: determining a current transmission direction of the bidirectional buck-boost DC-DC conversion circuit according to the current transmission direction requirement; determining a buck-boost mode and a buck-boost amplitude according to a voltage difference between two ends of the bidirectional buck-boost DC-DC conversion circuit; determining the target working state of the switching device in the case of the determined current transmission direction according to the buck-boost mode; determining a duty cycle of the driving voltage according to the buck-boost amplitude.

28. The electric energy transmission control method of any one of claims 23-27, further comprising: obtaining a voltage value of one end of a photovoltaic DC-DC conversion module connected to the photovoltaic interface, wherein the photovoltaic DC-DC conversion module is located between the photovoltaic interface connected to the photovoltaic panel and the first bidirectional buck-boost DC-DC conversion circuit, and is configured to convert direct current of a third voltage from the photovoltaic interface into direct current of a fourth voltage; determining a buck-boost mode and a buck-boost amplitude of the photovoltaic DC-DC conversion module according to the voltage value and a target voltage of the photovoltaic DC-DC conversion; determining a target working state of a switching device of the photovoltaic DC-DC conversion module according to the buck-boost mode, which is a working state conforming to the corresponding buck-boost mode in the case of the current direction from the photovoltaic interface to the first bidirectional buck-boost DC-DC conversion circuit; determining a target duty cycle according to the buck-boost amplitude of the photovoltaic DC-DC conversion module; determining a voltage output to the corresponding switching device of the photovoltaic DC-DC conversion module according to the target duty cycle.

29. An electric energy transmission controller, comprising: a memory; and a processor coupled to the memory, the processor configured to perform the method of any of claims 23 to 28 based on instructions stored in the memory.

30. A non-transitory computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the method of any of claims 23 to 28.

31. A computer program product comprising computer programs or instructions which, when executed by a processor, implement the method of any of claims 23 to 28.

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