Energy storage converter equipment and electric energy distribution method

Abstract

The invention discloses energy storage converter equipment and an electric energy distribution method. The energy storage converter device comprises: a DC bus; the power conversion unit is electrically connected to the direct current bus, and the power conversion unit is configured to be electrically connected with multiple of the direct current power supply, the battery module and the alternating current power supply; the control unit is electrically connected with the power conversion unit; the control unit is configured to: output one of a first loop control signal and a second loop control signal to the power conversion unit; and / or outputting one of the third loop control signal and the fourth loop control signal to the power conversion unit; and / or outputting one of the fifth loop control signal and the sixth loop control signal to the power conversion unit.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage and current conversion device and an electric energy distribution method. Background Art

[0002] In current energy storage and conversion equipment, since there are multiple sources of energy input and output, and some energy flows in both directions, it is necessary to provide appropriate control signals to each part during the actual control process to achieve reasonable distribution of energy and avoid overvoltage, undervoltage and other abnormalities during the energy conversion process.

[0003] In the related art, in order to realize energy distribution and control in energy storage and conversion equipment, control logic is preset, and the control logic of each part is determined according to the input power and load power of each part, thereby controlling the energy distribution of each part. Summary of the invention

[0004] The embodiments of the present application provide an energy storage and conversion device and an electric energy distribution method, which improve the technical problems that the energy storage and conversion device relies on software logic to distribute and control energy, and the control process has lags and cannot respond quickly.

[0005] In a first aspect, an embodiment of the present application provides an energy storage and conversion device, comprising: a DC bus; a power conversion unit, electrically connected to the DC bus, the power conversion unit being configured to be electrically connected to a plurality of DC power supplies, battery modules and AC power supplies; a control unit, electrically connected to the power conversion unit, the control unit being configured to perform the following operations: outputting one of a first loop control signal and a second loop control signal to the power conversion unit; and / or, outputting one of a third loop control signal and a fourth loop control signal to the power conversion unit; and / or, outputting one of a fifth loop control signal and a sixth loop control signal to the power conversion unit. The first loop control signal is generated based on the output voltage of the DC power supply and the first threshold voltage, and the second loop control signal is generated based on the bus voltage of the DC bus and the second threshold voltage; the third loop control signal is generated based on the charging current of the power conversion unit and the first target current, or based on the discharging current of the power conversion unit and the second target current, and the fourth loop control signal is generated based on the third threshold voltage or the fourth threshold voltage, and the bus voltage of the DC bus; the fifth loop control signal is generated based on the power supply current of the power conversion unit and the third target current, or based on the discharging current of the power conversion unit and the fourth target current, and the sixth loop control signal is generated based on the fifth threshold voltage or the sixth threshold voltage, and the bus voltage of the DC bus.

[0006] The control unit generates loop control signals for each energy inflow and outflow direction to achieve the distribution management of energy input and output between the DC power supply, battery module and AC power supply. The above implementation does not require the setting of EMS or other software control logic. The control unit in the energy storage converter compares the two loop control signals and selects one output to achieve energy management mode switching. Rapid response is achieved based on the detected electrical parameters to improve the dynamic response speed of energy management.

[0007] In one or more embodiments of the present application, the power conversion unit includes: a first DC-DC converter, which is configured between a DC power supply and a DC bus, and a control unit is configured to output one of a first loop control signal and a second loop control signal to the first DC-DC converter; and / or, a second DC-DC converter, which is configured between a battery module and a DC bus, and a control unit is configured to output one of a third loop control signal and a fourth loop control signal to the second DC-DC converter; and / or, a DC-AC converter, which is configured between an AC power supply and a DC bus, and a control unit is configured to output one of a fifth loop control signal and a sixth loop control signal to the DC-AC converter.

[0008] The first DC-DC converter, the second DC-DC converter and the DC-AC converter respectively realize energy distribution of the DC power supply, the battery module and the AC power supply, and realize energy management on multiple paths.

[0009] In one or more embodiments of the present application, the first DC-DC converter is a unidirectional DC-DC converter. The control unit is configured to generate a first loop control signal based on the difference between the output voltage of the DC power supply and the first threshold voltage and the maximum power loop controller, and to generate a second loop control signal based on the difference between the bus voltage of the DC bus and the second threshold voltage and the first voltage regulation loop controller. The first threshold voltage is defined as the voltage corresponding to the maximum power point of the first DC-DC converter, and the second threshold voltage is the voltage regulation point voltage when the first DC-DC converter operates in the voltage regulation mode. The control unit is also configured to select one of the first loop control signal and the second loop control signal with a smaller signal duty cycle and output it to the first DC-DC converter.

[0010] The control unit selects one of the two loop control signals with a smaller signal duty cycle and outputs it to the first DC-DC converter, and switches the working mode of the first DC-DC converter according to the bus voltage, so that the energy on the DC bus is quickly balanced, and the energy storage conversion device has good dynamic response performance and simple control logic.

[0011] In one or more embodiments of the present application, the second DC-DC converter is a unidirectional DC-DC converter or a bidirectional DC-DC converter. In response to the second DC-DC converter operating in the charging mode, the control unit is configured to generate a third loop control signal based on the difference between the charging current of the second DC-DC converter and the first target current and the first constant current loop controller, and to generate a fourth loop control signal based on the difference between the bus voltage of the DC bus and the third threshold voltage and the second voltage regulation loop controller, defining the first target current as the constant current point current when the second DC-DC converter operates in the constant current charging mode, and the third threshold voltage as the voltage regulation point voltage when the second DC-DC converter operates in the voltage regulation charging mode; and / Or, in response to the second DC-DC converter operating in the discharge mode, the control unit is configured to generate a third loop control signal based on the difference between the discharge current of the second DC-DC converter and the second target current and the second constant current loop controller, and to generate a fourth loop control signal based on the difference between the bus voltage of the DC bus and the fourth threshold voltage and the third voltage regulation loop controller, defining the second target current as the constant current point current when the second DC-DC converter operates in the constant current discharge mode, and the fourth threshold voltage as the voltage regulation point voltage when the second DC-DC converter operates in the voltage regulation discharge mode. The control unit is also configured to select one of the third loop control signal and the fourth loop control signal with a smaller signal duty cycle and output it to the second DC-DC converter.

[0012] The control unit selects the one with the smaller signal duty cycle among the two loop control signals and outputs it to the second DC-DC converter, and switches the working mode of the second DC-DC converter according to the bus voltage, so that the energy on the DC bus can be quickly balanced, and the energy storage conversion device has good dynamic response performance and simple control logic.

[0013] In one or more embodiments of the present application, the DC-AC converter includes a unidirectional DC-AC converter or a bidirectional DC-AC converter, the unidirectional DC-AC converter includes an inverter circuit, and the bidirectional DC-AC converter includes an inverter circuit and a power factor correction circuit. In response to the inverter circuit being in working state, the control unit is configured to generate a fifth loop control signal based on the difference between the power supply current of the inverter circuit and the third target current and the third constant current loop controller, and to generate a sixth loop control signal based on the difference between the bus voltage of the DC bus and the fifth threshold voltage and the fourth voltage regulation loop controller, defining the third target current as the constant current point current when the inverter circuit operates in the constant current power supply mode, and the fifth threshold voltage as the voltage regulation point voltage when the inverter circuit operates in the voltage regulation power supply mode; and / or, in response to the power factor correction circuit being in working state, the control unit is configured to generate a fifth loop control signal based on the difference between the discharge current of the power factor correction circuit and the fourth target current and the fourth constant current loop controller, and to generate a sixth loop control signal based on the difference between the bus voltage of the DC bus and the sixth threshold voltage and the fifth voltage regulation loop controller, defining the fourth target current as the constant current point current when the power factor correction circuit operates in the constant current discharge mode, and the sixth threshold voltage as the voltage regulation point voltage when the power factor correction circuit operates in the voltage regulation discharge mode. The control unit is further configured to select one of the fifth loop control signal and the sixth loop control signal with a smaller signal duty cycle and output it to the inverter circuit or the power factor correction circuit.

[0014] The control unit selects the one with the smaller signal duty cycle among the two loop control signals and outputs it to the DC-AC converter, and switches the working mode of the DC-AC converter according to the bus voltage, so that the energy on the DC bus can be quickly balanced. The energy storage converter has good dynamic response performance and simple control logic.

[0015] In one or more embodiments of the present application, the magnitude relationship between the second threshold voltage, the third threshold voltage, the fourth threshold voltage, the fifth threshold voltage, and the sixth threshold voltage is: Upvref_2>Ubatref_2>Uinvref_1=Upfcref_2>Ubatref_1; or, Upvref_2>Ubatref_2>Ubatref_1>Uinvref_1=Upfcref_2.

[0016] By setting the threshold voltages of the subunits of the power conversion unit corresponding to each energy inflow and outflow direction in different working modes, the distribution management of energy input and output between the DC power supply, the battery module and the AC power supply can be realized, so that when the energy provided in the direction of providing energy is greater than the energy absorbed in the direction of absorbing energy, the subunits of the power conversion unit in the direction of absorbing energy can realize constant current mode operation, and the subunits in the direction of providing energy can realize voltage stabilization mode operation. The energy on the DC bus can be balanced within the normal range of the bus voltage, so that the bus voltage will not be too high or too low to trigger the protection action.

[0017] In a second aspect, an embodiment of the present application provides an electric energy distribution method, which is applied to the energy storage and conversion device of the first aspect, and the electric energy distribution method includes: collecting the output voltage of a DC power supply and the bus voltage of a DC bus; calculating a first voltage difference between a first threshold voltage of the DC power supply and the output voltage of the DC power supply, and a second voltage difference between a second threshold voltage and the bus voltage; calculating a first loop control signal corresponding to the first voltage difference based on a control algorithm of a maximum power loop controller, and calculating a second loop control signal corresponding to the second voltage difference based on a control algorithm of a first voltage regulation loop controller; comparing the signal duty cycles of the first loop control signal and the second loop control signal, and outputting the one with the smaller signal duty cycle between the first loop control signal and the second loop control signal to a power conversion unit.

[0018] After generating the first loop control signal and the second loop control signal, the one with the smaller signal duty cycle of the two loop control signals is output to the power conversion unit. When the signal duty cycle of a certain loop control signal is reduced from higher than that of another loop control signal to lower than that of another loop control signal, the output switching of the loop control signal is realized, and then the working mode of the power conversion unit is switched to maintain the energy balance in the energy storage and conversion device. When the DC power supply provides energy to the DC bus, if the energy provided is greater than the energy absorbed by other power modules from the DC bus, the sub-units of the power conversion unit corresponding to the other power modules operate in a constant current mode, and the sub-units of the power conversion unit corresponding to the DC power supply operate in a voltage stabilization mode. When the DC bus reaches the threshold voltage corresponding to the voltage stabilization mode, the energy provided by the DC power supply is consistent with the energy absorbed by other power modules, so that the bus voltage of the DC bus is stabilized near the threshold voltage, thereby avoiding excessive energy provided by the DC power supply and causing the bus voltage to be overvoltage. Correspondingly, if the energy provided by the DC power supply is less than the energy absorbed by other power modules from the DC bus, the subunits of the power conversion units corresponding to the other power modules operate in a voltage stabilization mode, and the subunits of the power conversion units corresponding to the DC power supply operate in a maximum power point mode. When the bus voltage of the DC bus is close to the threshold voltage corresponding to the subunit in the voltage stabilization mode, the bus voltage of the DC bus can be stabilized near the threshold voltage, thereby avoiding the bus voltage undervoltage caused by the energy provided by the DC power supply being too small. Through the above implementation, energy balance on the DC bus can be achieved, and overvoltage or undervoltage of the bus voltage can be avoided. In the above process, there is no need for software logic operation, and the control unit can achieve the switching of the working mode by comparing and analyzing the signal duty cycle.

[0019] In a third aspect, an embodiment of the present application provides an electric energy distribution method, which is applied to the energy storage and conversion device of the first aspect, and the electric energy distribution method includes: collecting the charging current or discharging current of the battery module and the bus voltage of the DC bus; based on the charging current or discharging current of the battery module, calculating the current error value of the second DC-DC converter in the constant current mode; and, based on the bus voltage, calculating the voltage error value of the second DC-DC converter in the voltage regulation mode; based on the control algorithm corresponding to the second DC-DC converter in the constant current mode, calculating the third loop control signal corresponding to the current error value, and, based on the control algorithm corresponding to the second DC-DC converter in the voltage regulation mode, calculating the fourth loop control signal corresponding to the voltage error value; comparing the signal duty cycles of the third loop control signal and the fourth loop control signal, and outputting the one with the smaller signal duty cycle between the third loop control signal and the fourth loop control signal to the power conversion unit.

[0020] After generating the third loop control signal and the fourth loop control signal, the one with the smaller signal duty cycle of the two loop control signals is output to the power conversion unit. When the signal duty cycle of a certain loop control signal is reduced from higher than that of another loop control signal to lower than that of another loop control signal, the output switching of the loop control signal is realized, and then the working mode of the power conversion unit is switched to maintain the energy balance in the energy storage and conversion device. Based on the third loop control signal or the fourth loop control signal, the sub-unit of the power conversion unit corresponding to the battery module can be switched between the constant current mode and the voltage regulation mode, so that when the bus voltage of the DC bus is close to the sub-unit in the voltage regulation mode, the bus voltage can be maintained near the threshold voltage corresponding to the sub-unit in the voltage regulation mode, thereby avoiding overvoltage or undervoltage of the bus voltage. In the above process, there is no need for software logic operation, and the control unit can realize the switching of the working mode by comparing and analyzing the signal duty cycle.

[0021] In one or more embodiments of the present application, based on the charging current or discharging current of the battery module, the current error value of the second DC-DC converter in the constant current mode is calculated, including: in response to the second DC-DC converter operating in the charging mode, calculating the first current difference between the charging current of the battery module and the first target current in the constant current charging mode; and / or, in response to the second DC-DC converter operating in the discharging mode, calculating the second current difference between the discharging current of the battery module and the second target current in the constant current discharging mode; based on the bus voltage, the voltage error value of the second DC-DC converter in the voltage regulation mode is calculated, including: in response to the second DC-DC converter operating in the charging mode, calculating the third voltage difference between the third threshold voltage and the bus voltage; and / or, in response to the second DC-DC converter operating in the discharging mode, calculating the fourth voltage difference between the fourth threshold voltage and the bus voltage.

[0022] By confirming the operation mode of the second DC-DC converter, the current difference and the voltage difference in the charging mode or the current difference and the voltage difference in the discharging mode are calculated respectively.

[0023] In one or more embodiments of the present application, based on the control algorithm corresponding to the second DC-DC converter being in constant current mode, a third loop control signal corresponding to the current error value is calculated, including: in response to the second DC-DC converter operating in charging mode, based on the control algorithm of the first constant current loop controller, a third loop control signal corresponding to the first current difference is calculated; and / or, in response to the second DC-DC converter operating in discharge mode, based on the control algorithm of the second constant current loop controller, a third loop control signal corresponding to the second current difference is calculated; based on the control algorithm corresponding to the second DC-DC converter being in voltage regulation mode, a fourth loop control signal corresponding to the voltage error value is calculated, including: in response to the second DC-DC converter operating in charging mode, based on the control algorithm of the second voltage regulation loop controller, a fourth loop control signal corresponding to the third voltage difference is calculated; in response to the second DC-DC converter operating in discharge mode, based on the control algorithm of the third voltage regulation loop controller, a fourth loop control signal corresponding to the fourth voltage difference is calculated.

[0024] By confirming the working mode of the second DC-DC converter, based on the current difference and the voltage difference, a third loop control signal and a fourth loop control signal are generated using the corresponding constant current loop controller and voltage stabilizing loop controller.

[0025] In a fourth aspect, an embodiment of the present application provides an electric energy distribution method, which is applied to the energy storage and conversion device of the first aspect, and the electric energy distribution method includes: collecting the power intake current or discharge current of the AC power supply and the bus voltage of the DC bus; based on the power intake current or discharge current of the AC power supply, calculating the current error value of the DC-AC converter in the constant current mode; and, based on the bus voltage, calculating the voltage error value of the DC-AC converter in the voltage regulation mode; based on the control algorithm corresponding to the DC-AC converter in the constant current mode, calculating the fifth loop control signal corresponding to the current error value, and, based on the control algorithm corresponding to the DC-AC converter in the voltage regulation mode, calculating the sixth loop control signal corresponding to the voltage error value; comparing the signal duty cycles of the fifth loop control signal and the sixth loop control signal, and outputting the one with the smaller signal duty cycle between the fifth loop control signal and the sixth loop control signal to the power conversion unit.

[0026] After generating the fifth loop control signal and the sixth loop control signal, the one with the smaller signal duty cycle of the two loop control signals is output to the power conversion unit. When the signal duty cycle of a certain loop control signal is reduced from higher than that of another loop control signal to lower than that of another loop control signal, the output switching of the loop control signal is realized, and then the working mode of the power conversion unit is switched to maintain the energy balance in the energy storage and conversion device. Based on the fifth loop control signal or the sixth loop control signal, the sub-unit of the power conversion unit corresponding to the AC power supply can be switched between the constant current mode and the voltage regulation mode, so that when the bus voltage of the DC bus is close to the sub-unit in the voltage regulation mode, the bus voltage can be maintained near the threshold voltage corresponding to the sub-unit in the voltage regulation mode, thereby avoiding overvoltage or undervoltage of the bus voltage. In the above process, there is no need to perform software logic operations, and the control unit can realize the switching of the working mode by comparing and analyzing the signal duty cycle.

[0027] In one or more embodiments of the present application, based on the power supply current or discharge current of the AC power supply, the current error value of the DC-AC converter in the constant current mode is calculated, including: in response to the inverter circuit being in a working state, calculating the third current difference between the power supply current of the AC power supply and the third target current in the constant current power supply mode; and / or, in response to the power factor correction circuit being in a working state, calculating the fourth current difference between the discharge current of the AC power supply and the fourth target current in the constant current discharge mode; based on the bus voltage, the voltage error value of the DC-AC converter in the voltage regulation mode is calculated, including: in response to the inverter circuit being in a working state, calculating the fifth voltage difference between the fifth threshold voltage and the bus voltage; and / or, in response to the power factor correction circuit being in a working state, calculating the sixth voltage difference between the sixth threshold voltage and the bus voltage.

[0028] According to the working states of the inverter circuit and the power factor correction circuit, the current difference and the voltage difference in the power-taking mode, or the current difference and the voltage difference in the discharge mode are calculated respectively.

[0029] In one or more embodiments of the present application, based on the control algorithm corresponding to the DC-AC converter being in constant current mode, a fifth loop control signal corresponding to the current error value is calculated, including: in response to the inverter circuit being in operation, based on the control algorithm of the third constant current loop controller, a fifth loop control signal corresponding to the third current difference is calculated; and / or, in response to the power factor correction circuit being in operation, based on the control algorithm of the fourth constant current loop controller, a fifth loop control signal corresponding to the fourth current difference is calculated; based on the control algorithm corresponding to the DC-AC converter being in voltage regulation mode, a sixth loop control signal corresponding to the voltage error value is calculated, including: in response to the inverter circuit being in operation, based on the control algorithm of the fourth voltage regulation loop controller, a sixth loop control signal corresponding to the fifth voltage difference is calculated; and / or, in response to the power factor correction circuit being in operation, based on the control algorithm of the fifth voltage regulation loop controller, a sixth loop control signal corresponding to the sixth voltage difference is calculated.

[0030] According to the working status of the inverter circuit and the power factor correction circuit, based on the current difference and the voltage difference, the corresponding constant current loop controller and the voltage stabilizing loop controller are used to generate the fifth loop control signal and the sixth loop control signal.

[0031] Compared with the prior art, the energy storage conversion device and the electric energy distribution method provided in the embodiment of the present application are electrically connected to the DC bus through the power conversion unit, and are electrically connected to at least two electric energy units in the DC power supply, the battery module and the AC power supply. The control unit outputs one of the first loop control signal and the second loop control signal to the power conversion unit, outputs one of the third loop control signal and the fourth loop control signal to the power conversion unit, and outputs one of the fifth loop control signal and the sixth loop control signal to the power conversion unit. The control unit can generate loop control signals for each energy inflow and outflow direction, thereby realizing the distribution management of energy input and output in each direction. In addition, in the above-mentioned embodiment, there is no need to set EMS or other software control logic. The control unit in the energy storage conversion device compares the two loop control signals and selects one output to realize the distribution and management of electric energy and switch the working mode of the power conversion unit. According to the detected electrical parameters, a fast response is achieved to meet complex instantaneous change situations and improve the dynamic response speed of energy management. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of an energy storage and current conversion device provided in one embodiment of the present application;

[0033] Figure 2 is a structural schematic diagram of an energy storage and current conversion device provided in another embodiment of the present application;

[0034] Figure 3is a structural schematic diagram of an energy storage and current conversion device provided by another embodiment of the present application;

[0035] Figure 4 is a structural schematic diagram of an energy storage and current conversion device provided in yet another embodiment of the present application;

[0036] Figure 5 is a schematic diagram of the structure of a power conversion unit provided in one embodiment of the present application;

[0037] Figure 6 is a schematic structural diagram of a power conversion unit provided by another embodiment of the present application;

[0038] Figure 7 1 is a schematic diagram of selecting and outputting a first loop control signal and a second loop control signal provided by an embodiment of the present application;

[0039] Figure 8 It is a schematic diagram of selecting and outputting the third loop control signal and the fourth loop control signal of the battery module in the charging mode provided by an embodiment of the present application;

[0040] Fig. 9 It is a schematic diagram of selecting and outputting the third loop control signal and the fourth loop control signal of the battery module in the discharge mode provided by an embodiment of the present application;

[0041] Fig.10 It is a schematic diagram of selecting and outputting the fifth loop control signal and the sixth loop control signal of the AC power supply in the power-taking mode provided by an embodiment of the present application;

[0042] Fig.11 It is a schematic diagram of selecting and outputting the fifth loop control signal and the sixth loop control signal of the AC power supply in the discharge mode provided by an embodiment of the present application;

[0043] Fig.12 It is a flowchart of an electric energy distribution method provided in an embodiment of the present application;

[0044] Fig.13 is a flow chart of an electric energy distribution method provided by another embodiment of the present application;

[0045] Fig.14 is a flow chart of an electric energy distribution method provided by another embodiment of the present application;

[0046] Fig.15 It is a schematic diagram of the structure of an electronic device provided in one embodiment of the present application.

[0047] In the attached figure:

[0048] DC-BUS, DC bus; 10, power conversion unit; 20, DC power supply; 30, battery module; 40, AC power supply; 50, control unit; 11, first DC-DC converter; 12, second DC-DC converter; 13, DC-AC converter. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. The following specific implementation methods are exemplary rather than limiting, and are intended to provide a basic understanding of the present application, and are not intended to confirm the key or decisive elements of the present invention or to limit the scope of protection.

[0050] In the description of this application, connection can be direct connection, indirect connection through an intermediate medium, or internal connection between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application are understood according to specific circumstances.

[0051] The embodiment of the present application provides an energy storage and current conversion device and an electric energy distribution method. The specific implementation of the embodiment of the present application is further described below in conjunction with the accompanying drawings.

[0052] Energy storage conversion equipment

[0053] Figure 1 FIG. 1 shows a schematic diagram of the module structure of an energy storage converter device provided by an embodiment of the present application. Figure 1 As shown, the energy storage converter includes a DC bus DC-BUS, a power conversion unit 10 and a control unit 50 .

[0054] In some embodiments of the present application, the energy storage system includes an energy storage converter, and multiple of a DC power supply 20, a battery module 30, and an AC power supply 40, and the power conversion unit 10 is electrically connected to the DC bus DC-BUS, and is electrically connected to multiple of the DC power supply 20, the battery module 30, and the AC power supply 40. As a specific example of the present application, the DC power supply 20 includes a photovoltaic unit, and the AC power supply 40 includes a mains supply.

[0055] The power conversion unit 10 is electrically connected to a plurality of the DC power source 20, the battery module 30 and the AC power source 40, including:

[0056] Please refer to Figure 1 In a first optional embodiment, the power conversion unit 10 is electrically connected to the DC power supply 20, the battery module 30 and the AC power supply 40 respectively, and the energy storage and conversion device in this embodiment realizes energy distribution among the DC power supply 20, the battery module 30 and the AC power supply 40.

[0057] Please refer to Figure 2 In a second optional implementation, the power conversion unit 10 is electrically connected to the DC power supply 20 and the battery module 30 respectively, and the energy storage and conversion device in this implementation realizes energy distribution between the DC power supply 20 and the battery module 30.

[0058] Please refer to Figure 3 In a third optional implementation, the power conversion unit 10 is electrically connected to the DC power supply 20 and the AC power supply 40 respectively, and the energy storage and conversion device in this implementation realizes energy distribution between the DC power supply 20 and the AC power supply 40.

[0059] Please refer to Figure 4 In a fourth optional implementation, the power conversion unit 10 is electrically connected to the battery module 30 and the AC power source 40 respectively, and the energy storage and conversion device in this implementation realizes energy distribution between the battery module 30 and the AC power source 40.

[0060] The control unit 50 is electrically connected to the power conversion unit 10, and the control unit 50 outputs a corresponding loop control signal to the power conversion unit 10, so that the power conversion unit 10 works in different modes to achieve energy distribution among the DC power supply 20, the battery module 30 and the AC power supply 40.

[0061] like Figure 1 As shown, in a first optional embodiment, the power conversion unit 10 is electrically connected to the DC power supply 20, the battery module 30 and the AC power supply 40, respectively, and the control unit 50 outputs one of the first loop control signal and the second loop control signal to the power conversion unit 10, outputs one of the third loop control signal and the fourth loop control signal to the power conversion unit 10, and outputs one of the fifth loop control signal and the sixth loop control signal to the power conversion unit 10, thereby switching the working mode of the power conversion unit 10.

[0062] like Figure 2 As shown, in a second optional embodiment, the power conversion unit 10 is electrically connected to the DC power supply 20 and the battery module 30, respectively, and the control unit 50 outputs one of the first loop control signal and the second loop control signal to the power conversion unit 10, and outputs one of the third loop control signal and the fourth loop control signal to the power conversion unit 10, thereby switching the working mode of the power conversion unit 10.

[0063] like Figure 3As shown, in a third optional embodiment, the power conversion unit 10 is electrically connected to the DC power supply 20 and the AC power supply 40, respectively, and the control unit 50 outputs one of the first loop control signal and the second loop control signal to the power conversion unit 10, and outputs one of the fifth loop control signal and the sixth loop control signal to the power conversion unit 10, thereby switching the working mode of the power conversion unit 10.

[0064] like Figure 4 As shown, in a fourth optional embodiment, the power conversion unit 10 is electrically connected to the battery module 30 and the AC power supply 40, respectively, and the control unit 50 outputs one of the third loop control signal and the fourth loop control signal to the power conversion unit 10, and outputs one of the fifth loop control signal and the sixth loop control signal to the power conversion unit 10, thereby switching the working mode of the power conversion unit 10.

[0065] The first loop control signal is generated based on the output voltage of the DC power supply 20 and the first threshold voltage.

[0066] The second loop control signal is generated based on the bus voltage of the DC bus DC-BUS and a second threshold voltage.

[0067] The third loop control signal is generated based on the charging current of the power conversion unit 10 and the first target current, or is generated based on the discharging current of the power conversion unit 10 and the second target current.

[0068] The fourth loop control signal is generated based on the third threshold voltage and the bus voltage of the DC bus DC-BUS, or based on the fourth threshold voltage and the bus voltage of the DC bus DC-BUS.

[0069] The fifth loop control signal is generated based on the power-drawing current of the power conversion unit 10 and the third target current, or based on the discharging current of the power conversion unit 10 and the fourth target current.

[0070] The sixth loop control signal is generated based on the fifth threshold voltage and the bus voltage of the DC bus DC-BUS, or based on the sixth threshold voltage and the bus voltage of the DC bus DC-BUS.

[0071] In some embodiments, the power conversion unit 10 includes a plurality of subunits, each of which is electrically connected to a plurality of the DC power source 20, the battery module 30, or the AC power source 40, and the power transmission with the DC bus DC-BUS is realized through the plurality of subunits. For example, the power conversion unit 10 includes a first subunit electrically connected to the DC power source 20, and the first subunit realizes the energy transmission and control between the DC power source 20 and the DC bus DC-BUS; the power conversion unit 10 includes a second subunit electrically connected to the battery module 30, and the second subunit realizes the energy transmission and control between the battery module 30 and the DC bus DC-BUS; the power conversion unit 10 includes a third subunit electrically connected to the AC power source 40, and the third subunit realizes the energy transmission and control between the AC power source 40 and the DC bus DC-BUS.

[0072] The first loop control signal and the second loop control signal are input to the first subunit, and the two loop control signals correspond to the two working modes of the first subunit respectively.

[0073] The control unit 50 inputs the first loop control signal to the first subunit, and the first subunit operates in a working mode corresponding to the first loop control signal, and realizes energy transmission and control between the DC power supply 20 and the DC bus DC-BUS based on the first loop control signal.

[0074] The control unit 50 inputs the second loop control signal to the first subunit, and the first subunit operates in an operating mode corresponding to the second loop control signal, and realizes energy transmission and control between the DC power supply 20 and the DC bus DC-BUS based on the second loop control signal.

[0075] The third loop control signal and the fourth loop control signal are input to the second subunit, and the two loop control signals correspond to the two working modes of the second subunit respectively.

[0076] The control unit 50 inputs the third loop control signal to the second subunit, and the second subunit operates in a working mode corresponding to the third loop control signal, and realizes energy transmission and control between the battery module 30 and the DC bus DC-BUS based on the third loop control signal.

[0077] The control unit 50 inputs the fourth loop control signal to the second subunit, and the second subunit operates in the operating mode corresponding to the fourth loop control signal, and realizes energy transmission and control between the battery module 30 and the DC bus DC-BUS based on the fourth loop control signal.

[0078] The fifth loop control signal and the sixth loop control signal are input to the third subunit, and the two loop control signals correspond to the two working modes of the third subunit respectively.

[0079] The control unit 50 inputs the fifth loop control signal to the third subunit, and the third subunit operates in the operating mode corresponding to the fifth loop control signal, and realizes energy transmission and control between the AC power supply 40 and the DC bus DC-BUS based on the fifth loop control signal.

[0080] The control unit 50 inputs the sixth loop control signal to the third subunit, and the third subunit operates in the operating mode corresponding to the sixth loop control signal, and realizes energy transmission and control between the AC power supply 40 and the DC bus DC-BUS based on the fifth loop control signal.

[0081] In the above-mentioned implementation modes corresponding to the four connection relationships between the power conversion unit 10 and the DC power supply 20, the battery module 30 and the AC power supply 40, the loop control signal output by the control unit 50 is generated based on the corresponding implementation modes.

[0082] In some embodiments of the present application, the first loop control signal is generated based on the output voltage of the DC power supply 20 and the first threshold voltage. The first loop control signal controls the power conversion unit 10 to adjust the output voltage of the DC power supply 20 using the first threshold voltage as the target voltage. That is, the first loop control signal causes the first subunit of the power conversion unit 10 to operate in an operating mode in which the output voltage of the DC power supply 20 maintains the first threshold voltage. At this time, the input voltage of the first DC-DC converter is maintained at the first threshold voltage, that is, the output voltage of the DC power supply 20. It is understandable that the output voltage of the DC power supply 20 is the input voltage of the first subunit. In some embodiments of the present application, the first subunit is the first DC-DC converter 11.

[0083] The second loop control signal is generated based on the bus voltage of the DC bus DC-BUS and the second threshold voltage. The second loop control signal controls the power conversion unit 10 to adjust the bus voltage of the DC bus DC-BUS using the second threshold voltage as the target voltage. That is, the second loop control signal causes the first subunit to operate in an operating mode in which the bus voltage of the DC bus DC-BUS maintains the second threshold voltage.

[0084] The control unit 50 outputs one of the first loop control signal and the second loop control signal to the power conversion unit 10, so that when the power conversion unit 10 is connected to the DC power supply 20, the first subunit operates in an operating mode in which the output voltage of the DC power supply 20 maintains a first threshold voltage, or the first subunit operates in an operating mode in which the bus voltage of the DC bus DC-BUS maintains a second threshold voltage.

[0085] The output voltage of the DC power supply 20 maintains the first threshold voltage, which means that the power conversion unit 10 adjusts the output voltage of the DC power supply 20 so that the output voltage is close to or equal to the first threshold voltage. The bus voltage of the DC bus DC-BUS maintains the second threshold voltage, which means that the power conversion unit 10 adjusts the output voltage of the DC power supply 20 so that the bus voltage of the DC bus DC-BUS is close to or equal to the second threshold voltage.

[0086] In some embodiments of the present application, the third loop control signal is generated based on the charging current of the second subunit and the first target current, or based on the discharging current of the second subunit and the second target current.

[0087] When the battery module 30 is charged, that is, the second subunit is operating in the charging mode, the first current sensor detects the charging current of the second subunit, and the third loop control signal controls the second subunit to adjust the charging current of the second subunit based on the first target current. That is, during the charging process of the battery module 30, the third loop control signal causes the second subunit to operate in a working mode that allows the charging current of the second subunit to maintain the first target current. It is understandable that the charging current of the second subunit is the current for charging the battery module.

[0088] When the battery module 30 is discharging, that is, the second subunit is operating in the discharge mode, the first current sensor detects the discharge current of the second subunit, and the third loop control signal controls the second subunit to adjust the discharge current of the second subunit based on the second target current. That is, during the discharge process of the battery module 30, the third loop control signal causes the second subunit to operate in an operating mode that allows the discharge current of the second subunit to maintain the second target current.

[0089] The fourth loop control signal is generated based on the bus voltage of the DC bus DC-BUS and the third threshold voltage, or based on the bus voltage of the DC bus DC-BUS and the fourth threshold voltage.

[0090] When the battery module 30 is charged, that is, the second subunit operates in the charging mode, the fourth loop control signal controls the second subunit to adjust the bus voltage of the DC bus DC-BUS based on the third threshold voltage. That is, during the charging process of the battery module 30, the fourth loop control signal causes the second subunit to operate in a working mode in which the bus voltage of the DC bus DC-BUS is maintained at the third threshold voltage.

[0091] When the battery module 30 is discharged, that is, the second subunit is operating in the discharge mode, the fourth loop control signal controls the second subunit to adjust the bus voltage of the DC bus DC-BUS based on the fourth threshold voltage. That is, during the discharge process of the battery module 30, the fourth loop control signal causes the second subunit to operate in an operating mode in which the bus voltage of the DC bus DC-BUS is maintained at the fourth threshold voltage.

[0092] In the above embodiment, when the control unit 50 outputs the third loop control signal to the second subunit, the second subunit operates in a constant current mode, and the constant current mode corresponds to the first target current and the second target current, respectively, based on the battery module 30 being in a charging state or a discharging state. When the control unit 50 outputs the fourth loop control signal to the second subunit, the second subunit operates in a voltage stabilization mode, and the voltage stabilization mode corresponds to the third threshold voltage and the fourth threshold voltage, respectively, based on the battery module 30 being in a charging state or a discharging state.

[0093] In some embodiments of the present application, the fifth loop control signal is generated based on the power supply current of the third subunit and the third target current, or based on the discharge current of the third subunit and the fourth target current.

[0094] When the third subunit is in the power-drawing mode and obtains energy from the DC-BUS, the second current sensor detects the power-drawing current of the third subunit. The fifth loop control signal controls the third subunit to adjust the power-drawing current of the third subunit based on the third target current. That is, during the power-drawing process of the third subunit, the fifth loop control signal enables the third subunit to operate in a working mode that enables the power-drawing current of the third subunit to maintain the third target current.

[0095] When the third subunit is in the discharge mode and provides energy to the DC bus DC-BUS, the second current sensor detects the discharge current of the third subunit. The fifth loop control signal controls the third subunit to adjust the discharge current of the third subunit based on the fourth target current. That is, during the discharge process of the third subunit, the fifth loop control signal causes the third subunit to operate in an operating mode that causes the discharge current of the third subunit to maintain the fourth target current.

[0096] The sixth loop control signal is generated based on the bus voltage of the DC bus DC-BUS and the fifth threshold voltage, or based on the bus voltage of the DC bus DC-BUS and the sixth threshold voltage.

[0097] When the third subunit is in the power-taking mode and obtains energy from the DC bus DC-BUS, the sixth loop control signal controls the third subunit to adjust the bus voltage of the DC bus DC-BUS based on the fifth threshold voltage. That is, during the power-taking process of the third subunit, the sixth loop control signal enables the third subunit to operate in an operating mode in which the bus voltage of the DC bus DC-BUS maintains the fifth threshold voltage.

[0098] When the third subunit is in the discharge mode and provides energy to the DC bus DC-BUS, the sixth loop control signal controls the third subunit to adjust the bus voltage of the DC bus DC-BUS based on the sixth threshold voltage. That is, during the discharge process of the third subunit, the sixth loop control signal enables the third subunit to operate in an operating mode that maintains the bus voltage of the DC bus DC-BUS at the sixth threshold voltage.

[0099] In the above embodiment, when the control unit 50 outputs the fifth loop control signal to the third subunit, the third subunit operates in a constant current mode, and based on the third subunit being in a power-taking state or a discharge state, the constant current mode corresponds to the third target current and the fourth target current, respectively. When the control unit 50 outputs the sixth loop control signal to the third subunit, the third subunit operates in a voltage stabilization mode, and based on the third subunit being in a power-taking state or a discharge state, the voltage stabilization mode corresponds to the fifth threshold voltage and the sixth threshold voltage, respectively.

[0100] In some embodiments of the present application, the power conversion unit 10 is electrically connected to the DC bus DC-BUS, and is electrically connected to at least two of the DC power supply 20, the battery module 30, and the AC power supply 40. When the power conversion unit 10 is electrically connected to the DC power supply 20, the control unit 50 outputs one of the first loop control signal and the second loop control signal to the power conversion unit 10, so that the power conversion unit 10 maintains the output voltage of the DC power supply 20 at the first threshold voltage, or maintains the bus voltage of the DC bus DC-BUS at the second threshold voltage. When the power conversion unit 10 is connected to the battery module 30, the control unit 50 outputs one of the third loop control signal and the fourth loop control signal to the power conversion unit 10, so that the power conversion unit 10 operates in a constant current state, or maintains the bus voltage of the DC bus DC-BUS in a regulated voltage state. When the power conversion unit 10 is connected to the AC power supply 40, the control unit 50 outputs one of the fifth loop control signal and the sixth loop control signal to the power conversion unit 10, so that the power conversion unit 10 is maintained in a constant current state, or the bus voltage of the DC bus DC-BUS is maintained in a regulated voltage state. The control unit 50 generates loop control signals for each energy inflow and outflow direction, thereby realizing the distribution management of energy input and energy output in each direction. In addition, in the above-mentioned embodiment, there is no need to set up an EMS (Energy Management System) or other software control logic. The control unit 50 in the energy storage and conversion device compares the two loop control signals and selects one output to realize energy distribution. A fast response is achieved according to the detected electrical parameters to meet complex instantaneous change situations and improve the dynamic response speed of energy management.

[0101] Please refer to Figure 5 According to some embodiments of the present application, the power conversion unit 10 includes at least two of a first DC-DC converter 11, a second DC-DC converter 12, and a DC-AC converter 13. As a specific example of the present application, the first subunit includes the first DC-DC converter 11, the second subunit includes the second DC-DC converter 12, and the third subunit includes the DC-AC converter 13.

[0102] The specific device types included in the power conversion unit 10 are determined according to the connection relationship between the power conversion unit 10 and the DC power supply 20, the battery module 30 and the AC power supply 40. For example, the power conversion unit 10 is connected to the DC power supply 20, and the power conversion unit 10 includes a first DC-DC converter 11; the power conversion unit 10 is connected to the battery module 30, and the power conversion unit 10 includes a second DC-DC converter 12; the power conversion unit 10 is connected to the AC power supply 40, and the power conversion unit 10 includes a DC-AC converter. The power conversion unit 10 is connected to at least two of the DC power supply 20, the battery module 30 and the AC power supply 40, and accordingly, the power conversion unit 10 includes at least two of the first DC-DC converter 11, the second DC-DC converter 12 and the DC-AC converter 13.

[0103] like Figure 1 As shown, the first DC-DC converter 11 is arranged between the DC power supply 20 and the DC bus DC-BUS, and is electrically connected to the DC power supply 20 and the DC bus DC-BUS respectively. The control unit 50 outputs one of the first loop control signal and the second loop control signal to the first DC-DC converter 11.

[0104] The second DC-DC converter 12 is disposed between the battery module 30 and the DC bus DC-BUS, and is electrically connected to the battery module 30 and the DC bus DC-BUS respectively. The control unit 50 outputs one of the third loop control signal and the fourth loop control signal to the second DC-DC converter 12.

[0105] The DC-AC converter 13 is disposed between the AC power source 40 and the DC bus DC-BUS, and is electrically connected to the AC power source 40 and the DC bus DC-BUS respectively. The control unit 50 outputs one of the fifth loop control signal and the sixth loop control signal to the DC-AC converter 13.

[0106] In this embodiment, the first DC-DC converter 11 adjusts the output voltage of the DC power supply 20 or the bus voltage of the DC bus DC-BUS, and maintains the output voltage of the DC power supply 20 at a first threshold voltage when receiving the first loop control signal, and maintains the bus voltage of the DC bus DC-BUS at a second threshold voltage when receiving the second loop control signal. The second DC-DC converter 12 adjusts the current between the battery module 30 and the DC bus DC-BUS or the bus voltage of the DC bus DC-BUS, and maintains the current between the battery module 30 and the DC bus DC-BUS at a constant current when receiving the third loop control signal, and maintains the bus voltage of the DC bus DC-BUS at a constant voltage when receiving the fourth loop control signal. The DC-AC converter 13 realizes current adjustment between the AC power supply 40 and the DC bus DC-BUS or bus voltage adjustment of the DC bus DC-BUS. When receiving the fifth loop control signal, the current between the AC power supply 40 and the DC bus DC-BUS is maintained at a constant current. When receiving the sixth loop control signal, the bus voltage of the DC bus DC-BUS is maintained at a constant voltage.

[0107] According to some embodiments of the present application, the first DC-DC converter 11 is a unidirectional DC-DC converter, and the voltage output by the DC power supply 20 is output to the DC bus DC-BUS through the first DC-DC converter 11 .

[0108] The control unit 50 generates a first loop control signal based on the output voltage of the DC power supply 20, the first threshold voltage and the maximum power loop controller, and generates a second loop control signal based on the bus voltage of the DC bus DC-BUS, the second threshold voltage and the first voltage regulation loop controller.

[0109] In some embodiments of the present application, the first threshold voltage is the voltage corresponding to the maximum power point of the DC power supply 20. Taking the DC power supply 20 as a photovoltaic module as an example, the first threshold voltage is the MPPT (Maximum Power Point Tracking) voltage of the photovoltaic module, which is calculated by the MPPT algorithm. The second threshold voltage is the corresponding voltage stabilization point voltage when the first DC-DC converter 11 operates in the voltage stabilization mode.

[0110] The output voltage of the DC power supply 20 refers to the voltage received by the first DC-DC converter 11, and the output voltage is collected by a voltage sampling circuit formed by an operational amplifier, a voltage dividing resistor, and a control unit 50. The control unit 50 samples the current signal and the voltage signal required in each of the following embodiments. As a specific example of the present application, the control unit 50 is a DSP (Digital Signal Processing, digital signal processor).

[0111] Please refer to Figure 7 , the first loop control signal Upvout_1 is generated as follows: after sampling the output voltage Upvfb of the DC power supply 20, the control unit 50 inputs the output voltage and a preset first threshold voltage Upvref_1 into the maximum power loop controller G1(S). The maximum power loop controller G1(S) calculates the first loop control signal Upvout_1 through an internal control loop according to the difference between the first threshold voltage Upvref_1 and the output voltage Upvfb of the DC power supply 20, and outputs the first loop control signal Upvout_1 to the first DC-DC converter 11. The first DC-DC converter 11 maintains the output voltage Upvfb of the DC power supply 20 at the first threshold voltage Upvref_1.

[0112] The second loop control signal Upvout_2 is generated in the following manner: after sampling the bus voltage Ubus of the DC bus DC-BUS, the control unit 50 inputs the bus voltage Ubus and a preset second threshold voltage Upvref_2 into the first voltage regulation loop controller G2(S). The first voltage regulation loop controller G2(S) calculates the second loop control signal Upvout_2 through an internal control loop based on the difference between the second threshold voltage Upvref_2 and the bus voltage Ubus, and outputs the second loop control signal Upvout_2 to the first DC-DC converter 11. The first DC-DC converter 11 maintains the bus voltage Ubus of the DC bus DC-BUS at the second threshold voltage Upvref_2.

[0113] After generating the first loop control signal Upvout_1 and the second loop control signal Upvout_2 , the control unit 50 selects one of the two loop control signals with a smaller signal duty cycle and outputs the PWM signal to the first DC-DC converter 11 .

[0114] In some embodiments of the present application, the control unit 50 generates the first loop control signal Upvout_1 and the second loop control signal Upvout_2 in real time. When the control unit 50 switches the output loop control signal based on the signal duty cycle, the working mode of the first DC-DC converter 11 is switched. For example, when the first loop control signal Upvout_1 is switched to the second loop control signal Upvout_2, the first DC-DC converter is switched from the working mode of maintaining the DC power supply 20 outputting a stable voltage to the working mode of maintaining the DC bus DC-BUS at the second threshold voltage Upvref_2.

[0115] In some embodiments of the present application including a DC power supply 20, the DC power supply 20 provides energy to the DC bus DC-BUS, because the power conversion unit 10 is also connected to at least one of the battery module 30 and the AC power supply 40. When the battery module 30 is charged, it receives energy from the DC bus DC-BUS provided by the DC power supply 20. The AC power supply 40 is a commercial power grid, and the grid receives energy provided by the DC power supply 20 from the DC bus DC-BUS.

[0116] When the energy provided by the DC power supply 20 is completely absorbed by the battery module 30 and / or the AC power supply 40, the DC power supply 20 continues to operate in the maximum power point tracking mode, i.e., the MPPT mode. At this time, the first loop control signal Upvout_1 generated by the control unit 50 maintains the output voltage Upvfb of the DC power supply 20 at the first threshold voltage Upvref_1, the second DC-DC converter 12 and / or the DC-AC converter operate in the voltage regulation mode, and the battery module 30 and / or the AC power supply 40 stably absorb the energy provided by the DC power supply 20 to the DC bus DC-BUS.

[0117] Taking the example of the AC power supply 40 absorbing the energy of the DC bus DC-BUS, the energy provided by the DC power supply 20 is completely absorbed, and the DC-AC converter works in the voltage regulation mode. At this time, the bus voltage Ubus of the DC bus DC-BUS is stabilized at the fifth threshold voltage Uinvref_1 corresponding to the DC-AC converter being in the power-taking state. When the bus voltage Ubus is maintained at the fifth threshold voltage Uinvref_1, the second threshold voltage Upvref_2 is greater than the fifth threshold voltage Uinvref_1, and the difference between the bus voltage Ubus received by the first voltage regulation loop controller G2 (S) and the second threshold voltage Upvref_2 is large. At this time, the first voltage regulation loop controller G2 (S) calculates the second loop control signal Upvout_2 based on the larger difference through the internal control loop. The signal duty cycle is greater than the signal duty cycle of the first loop control signal Upvout_1, and the control unit 50 selects the first loop control signal Upvout_1 with a smaller signal duty cycle to output to the first DC-DC converter 11. In some embodiments of the present application, the second threshold voltage Upvref_2 is 20 V greater than the fifth threshold voltage Uinvref_1. In some other embodiments of the present application, the second threshold voltage Upvref_2 is any value of 10 V, 15 V, 25 V, 35 V or any value of [10 V, 35 V] greater than the fifth threshold voltage Uinvref_1.

[0118] In some embodiments of the present application, when the battery module 30 completely absorbs the energy provided by the DC power supply 20, the second DC-DC converter 12 operates in a voltage-regulated charging mode, at which time the bus voltage Ubus of the DC bus DC-BUS is stabilized at a third threshold voltage Ubatref_1 corresponding to the second DC-DC converter 12 in the voltage-regulated charging mode, and the third threshold voltage Ubatref_1 is less than the fifth threshold voltage Uinvref_1. At this time, the difference between the second threshold voltage Upvref_2 received by the first voltage-regulated loop controller G2(S) and the bus voltage Ubus is large, and the signal duty cycle of the generated second loop control signal Upvout_2 is greater than the first loop control signal Upvout_1, and the control unit 50 selects the first loop control signal Upvout_1 with a smaller signal duty cycle to output to the first DC-DC converter 11. In some embodiments of the present application, the fifth threshold voltage Uinvref_1 is 10V greater than the third threshold voltage Ubatref_1. In some other embodiments of the present application, the fifth threshold voltage Uinvref_1 is greater than the third threshold voltage Ubatref_1 by any value of 5V, 8V, 15V or any value of [5V, 15V].

[0119] When the energy provided by the DC power supply 20 cannot be completely absorbed by the battery module 30 and / or the AC power supply 40, the excess energy pulls up the bus voltage Ubus of the DC bus DC-BUS. Since the first voltage regulation loop controller G2 (S) is continuously working, when the bus voltage Ubus of the DC bus DC-BUS increases, the difference between it and the second threshold voltage Upvref_2 decreases, so that the signal duty cycle of the second loop control signal Upvout_2 output by the first voltage regulation loop controller G2 (S) also decreases. When the bus voltage Ubus is increased to a value close to or equal to the second threshold voltage Upvref_2, the signal duty cycle of the second loop control signal Upvout_2 is less than the signal duty cycle of the first loop control signal Upvout_1. At this time, the control unit 50 selects a control signal with a smaller signal duty cycle, and switches the first loop control signal Upvout_1 output to the first DC-DC converter 11 to the second loop control signal Upvout_2. Under the control of the second loop control value signal, the first DC-DC converter 11 maintains the bus voltage Ubus of the DC bus DC-BUS at the second threshold voltage Upvref_2. The first DC-DC converter 11 operates in a voltage regulation mode, and can accurately determine the power generation of the DC power supply 20, thereby improving the accuracy of the power generation of the DC power supply.

[0120] In this embodiment, during the process of the DC power supply 20 providing energy, the control unit 50 generates a first loop control signal Upvout_1 according to the output voltage Upvfb of the DC power supply 20, and generates a second loop control signal Upvout_2 according to the bus voltage Ubus of the DC bus DC-BUS. When the battery module 30 or the AC power supply 40 cannot completely absorb the energy provided by the DC power supply 20, the bus voltage Ubus gradually increases, so that the signal duty cycle of the second loop control signal Upvout_2 gradually decreases. When the signal duty cycle of the second loop control signal Upvout_2 is reduced to be less than the signal duty cycle of the first loop control signal Upvout_1, the first DC-DC converter 11 receives the second loop control signal Upvout_2, and the first DC-DC converter 11 switches from the maximum power point tracking mode to the voltage regulation mode.

[0121] In the voltage stabilization mode, the energy provided by the DC power source 20 is consistent with the energy absorbed by the battery module 30 and / or the AC power source 40, so that the bus voltage Ubus can be stably maintained at the second threshold voltage Upvref_2.

[0122] When the first DC-DC converter 11 operates in the voltage regulation mode, if the energy absorbed by the battery module 30 and / or the AC power supply 40 is greater than the energy that can be provided by the DC power supply 20, the bus voltage Ubus will be gradually lowered, so that the signal duty cycle of the second loop control signal Upvout_2 will gradually increase, and the control unit 50 will switch the output second loop control signal Upvout_2 to the first loop control signal Upvout_1, so that the first DC-DC converter 11 switches from the voltage regulation mode to the maximum power point tracking mode.

[0123] Please refer to Figure 5 According to some embodiments of the present application, the second DC-DC converter 12 is a unidirectional DC-DC converter or a bidirectional DC-DC converter.

[0124] When the second DC-DC converter 12 is a unidirectional DC-DC converter, if the input end of the unidirectional DC-DC converter is connected to the battery module 30, and the output end is connected to the DC bus DC-BUS, the battery module 30 discharges to output energy; if the input end of the unidirectional DC-DC converter is connected to the DC bus DC-BUS, and the output end is connected to the battery module 30, the battery module 30 is charged to absorb energy.

[0125] When the second DC-DC converter 12 is a bidirectional DC-DC converter, the operation mode of the battery module 30 includes a charging mode and a discharging mode.

[0126] Please refer to Figure 8 When the second DC-DC converter 12 operates in the charging mode, that is, the battery module is charged, the control unit 50 is based on the charging current Ibatfb_1 of the second DC-DC converter 12, the first target current Ibatref_1 and the first constant current loop controller G 3-1 (S) Generate a third loop control signal Ibatout_1, and based on the bus voltage Ubus of the DC bus DC-BUS, the third threshold voltage Ubatref_1 and the second voltage regulation loop controller G 4-1 (S) Generate a fourth loop control signal Ubatout_1.

[0127] The first target current Ibatref_1 is the charging current when the second DC-DC converter 12 operates in the constant current charging mode, and the third threshold voltage Ubatref_1 is the stabilization point voltage when the second DC-DC converter 12 operates in the regulated voltage charging mode.

[0128] The third loop control signal Ibatout_1 is generated by: the control unit 50 obtains the charging current Ibatfb_1 by sampling the first current sensor (not shown), and inputs the charging current Ibatfb_1 and the first target current Ibatref_1 into the first constant current loop controller G 3-1 (S), the first constant current loop controller G 3-1 (S) According to the difference between the first target current Ibatref_1 and the charging current Ibatfb_1, a third loop control signal Ibatout_1 is calculated through an internal control loop, and the third loop control signal Ibatout_1 is output to the second DC-DC converter 12. The second DC-DC converter 12 maintains the charging current Ibatfb_1 at the first target current Ibatref_1, that is, the second DC-DC converter 12 operates in a constant current charging mode.

[0129] The fourth loop control signal Ubatout_1 is generated by sampling the bus voltage Ubus of the DC bus DC-BUS through a voltage sampling circuit composed of an operational amplifier, a voltage dividing resistor and a control unit 50, and inputting the bus voltage Ubus and the third threshold voltage Ubatref_1 into the second voltage regulation loop controller G 4-1 (S), the second voltage regulation loop controller G 4-1 (S) According to the difference between the third threshold voltage Ubatref_1 and the bus voltage Ubus, the fourth loop control signal Ubatout_1 is calculated through the internal control loop, and the fourth loop control signal Ubatout_1 is output to the second DC-DC converter 12. Then, the second DC-DC converter 12 maintains the bus voltage Ubus of the DC bus DC-BUS at the third threshold voltage Ubatref_1, that is, the second DC-DC converter 12 operates in the voltage regulated charging mode.

[0130] After generating the third loop control signal Ibatout_1 and the fourth loop control signal Ubatout_1 , the control unit 50 selects one of the two loop control signals with a smaller signal duty cycle and outputs the selected one to the second DC-DC converter 12 .

[0131] In the above embodiment, if the second DC-DC converter 12 operates in the charging mode, the second DC-DC converter 12 is a bidirectional DC-DC converter, or a unidirectional DC-DC converter whose output end is connected to the battery module 30 .

[0132] In the above embodiment, when the second DC-DC converter 12 operates in the charging mode, the battery module 30 receives energy from the DC bus DC-BUS. When the energy provided by the DC power supply 20 and / or the AC power supply 40 to the DC bus DC-BUS is greater than the energy absorbed by the battery module 30, the bus voltage Ubus will be pulled up. At this time, the difference between the bus voltage Ubus and the third threshold voltage Ubatref_1 is large, and the signal duty ratio of the fourth loop control signal Ubatout_1 is relatively large. The control unit 50 selects the third loop control signal Ibatout_1 to output to the second DC-DC converter 12, so that the second DC-DC converter 12 operates in the constant current charging mode.

[0133] When the energy provided by the DC power supply 20 and / or the AC power supply 40 to the DC bus DC-BUS is less than the energy absorbed by the battery module 30, the bus voltage Ubus of the DC bus DC-BUS gradually decreases. As the bus voltage Ubus decreases, the difference between the bus voltage Ubus and the third threshold voltage Ubatref_1 also gradually decreases. When the bus voltage Ubus decreases to a value close to or equal to the third threshold voltage Ubatref_1, the signal duty cycle of the fourth loop control signal Ubatout_1 is less than the signal duty cycle of the third loop control signal Ibatout_1, and the control unit 50 selects the fourth loop control signal Ubatout_1 to output to the second DC-DC converter 12, and the signal received by the second DC-DC converter 12 is switched to the fourth loop control signal Ubatout_1. At this time, the working mode of the second DC-DC converter 12 is switched from the constant current charging mode to the voltage regulated charging mode.

[0134] If the energy provided by the DC power supply 20 and / or the AC power supply 40 to the DC bus DC-BUS gradually increases and is greater than the energy absorbed by the battery module 30, the bus voltage Ubus of the DC bus DC-BUS gradually increases, and the signal duty cycle of the fourth loop control signal Ubatout_1 also gradually increases, so that the signal received by the second DC-DC converter 12 is switched to the third loop control signal Ibatout_1, and the operating mode of the second DC-DC converter 12 is switched from the voltage regulated charging mode to the constant current charging mode.

[0135] Please refer to Fig. 9 When the second DC-DC converter 12 operates in the discharge mode, the battery module 30 passes energy to the DC bus DC-BUS, and the control unit 50 controls the second constant current loop controller G based on the discharge current Ibatfb_2, the second target current Ibatref_2 and the second constant current loop controller G 3-2(S) Generate a third loop control signal Ibatout_2, and based on the bus voltage Ubus of the DC bus DC-BUS, the fourth threshold voltage Ubatref_2 and the third voltage regulation loop controller G 4-2 (S) Generate a fourth loop control signal Ubatout_2.

[0136] The second target current Ibatref_2 is the current when the second DC-DC converter 12 operates in the constant current discharge mode, and the fourth threshold voltage Ubatref_2 is the stabilization point voltage when the second DC-DC converter 12 operates in the stabilization voltage discharge mode.

[0137] The third loop control signal Ibatout_2 is generated as follows: the control unit 50 samples the discharge current Ibatfb_2 through the first current sensor, and inputs the discharge current Ibatfb_2 and the second target current Ibatref_2 into the second constant current loop controller G 3-2 (S), the second constant current loop controller G 3-2 (S) According to the difference between the second target current Ibatref_2 and the discharge current Ibatfb_2, a third loop control signal Ibatout_2 is calculated through an internal control loop, and the third loop control signal Ibatout_2 is output to the second DC-DC converter 12. The second DC-DC converter 12 maintains the discharge current Ibatfb_2 at the second target current Ibatref_2, that is, the second DC-DC converter 12 operates in a constant current discharge mode.

[0138] The fourth loop control signal Ubatout_2 is generated by: the control unit 50 samples the bus voltage Ubus of the DC bus DC-BUS, and inputs the bus voltage Ubus and the fourth threshold voltage Ubatref_2 to the third voltage regulation loop controller G 4-2 (S), the third voltage regulation loop controller G 4-2(S) According to the difference between the fourth threshold voltage Ubatref_2 and the bus voltage Ubus, the fourth loop control signal Ubatout_2 is obtained through the internal control loop calculation, and the fourth loop control signal Ubatout_2 is output to the second DC-DC converter 12, and the second DC-DC converter 12 maintains the bus voltage Ubus of the DC bus DC-BUS at the fourth threshold voltage Ubatref_2, that is, the second DC-DC converter 12 operates in the voltage-stabilized discharge mode. In some embodiments of the present application, the fourth threshold voltage Ubatref_2 is greater than the fifth threshold voltage Uinvref_1 and less than the second threshold voltage Upvref_2. As an example of the present application, the fourth threshold voltage Ubatref_2 is greater than the fifth threshold voltage Uinvref_1 by 10V, and the fourth threshold voltage Ubatref_2 is less than the second threshold voltage Upvref_2 by 10V. As other examples of the present application, the fourth threshold voltage Ubatref_2 is 5V, 8V, 15V or any value of [5V, 15V] greater than the fifth threshold voltage Uinvref_1, and the fourth threshold voltage Ubatref_2 is 5V, 10V, 15V, 20V or any value of [5V, 20V] less than the second threshold voltage Upvref_2.

[0139] After generating the third loop control signal Ibatout_2 and the fourth loop control signal Ubatout_2 , the control unit 50 selects one of the two loop control signals with a smaller signal duty cycle and outputs it to the second DC-DC converter 12 .

[0140] In the above embodiment, if the second DC-DC converter 12 operates in the discharge mode, the second DC-DC converter 12 is a bidirectional DC-DC converter, or a unidirectional DC-DC converter whose output end is connected to the DC bus DC-BUS.

[0141] In the above embodiment, the battery module 30 discharges to provide energy to the DC bus DC-BUS. When the energy absorbed by the AC power supply 40 from the DC bus DC-BUS is less than the energy provided by the battery module 30, the bus voltage Ubus will gradually increase. When the bus voltage Ubus increases to a value close to or equal to the fourth threshold voltage Ubatref_2, the signal duty cycle of the fourth loop control signal Ubatout_2 is less than the signal duty cycle of the third loop control signal Ibatout_2, and the control unit 50 outputs the fourth loop control signal Ubatout_2 to the second DC-DC converter 12, and the second DC-DC converter 12 operates in a voltage-stabilized discharge mode.

[0142] Correspondingly, if the energy absorbed by the AC power supply 40 from the DC bus DC-BUS gradually increases and is greater than the energy provided by the battery module 30, the bus voltage Ubus of the DC bus DC-BUS will gradually decrease, and the signal duty cycle of the fourth loop control signal Ubatout_2 will also gradually increase, so that the signal received by the second DC-DC converter 12 is switched to the third loop control signal Ibatout_2, and the working mode of the second DC-DC converter 12 is switched from the voltage regulated discharge mode to the constant current discharge mode.

[0143] In this embodiment, no matter the battery module 30 provides energy or absorbs energy, the control unit 50 switches the second DC-DC converter 12 between the voltage regulation mode and the constant current mode according to the change of the bus voltage Ubus of the DC bus DC-BUS.

[0144] Please continue to refer to Figure 5 According to some embodiments of the present application, the DC-AC converter 13 is a unidirectional DC-AC converter 13 or a bidirectional DC-AC converter 13. The unidirectional DC-AC converter 13 includes an inverter circuit, which converts the bus voltage Ubus of the DC bus DC-BUS into an AC voltage and provides it to the AC power supply 40, and the AC power supply 40 draws power from the DC bus DC-BUS; the bidirectional DC-AC converter 13 includes an inverter circuit and a power factor correction circuit. When the inverter circuit is working, the AC power supply 40 draws power from the DC bus DC-BUS, and when the power factor correction circuit is working, the AC power supply 40 discharges to the DC bus DC-BUS.

[0145] As an optional implementation, please refer to Figure 6 The DC-AC converter 13 includes an inverter circuit 131, which is connected between the DC bus DC-BUS and the load Load, and is electrically connected to the DC bus DC-BUS and the load Load respectively. The inverter circuit 131 converts the bus voltage Ubus into an AC voltage through an inverter to supply power to the load Load. In this embodiment, the AC power source 40 is connected to the battery module 30 through a power factor correction circuit 132, and the power factor correction circuit 132 rectifies the AC voltage output by the AC power source 40 into a DC voltage to charge the battery module 30.

[0146] Please refer to Figure 5 and Fig.10 When the inverter circuit of the DC-AC converter 13 is in operation, the control unit 50 controls the inverter circuit based on the power supply current Igridfb_1, the third target current Igridref_1 and the third constant current loop controller G 5-1(S) Generate a fifth loop control signal Igridout_1, and based on the bus voltage Ubus of the DC bus DC-BUS, the fifth threshold voltage Uinvref_1 and the fourth voltage regulation loop controller G 6-1 (S) Generate a sixth loop control signal Ugridout_1. It can be understood that, in this embodiment, the DC-AC converter 13 is a bidirectional converter.

[0147] The third target current Igridref_1 is the current when the DC-AC converter 13 operates in the constant current power supply mode, and the fifth threshold voltage Uinvref_1 is the voltage when the DC-AC converter 13 operates in the voltage stabilization power supply mode.

[0148] The fifth loop control signal Igridout_1 is generated as follows: after the control unit 50 obtains the power-taking current Igridfb_1 of the inverter circuit through sampling by the second current sensor, the power-taking current Igridfb_1 and the third target current Igridref_1 are input into the third constant current loop controller G 5-1 (S), the third constant current loop controller G 5-1 (S) According to the difference between the third target current Igridref_1 and the power-drawing current Igridfb_1, a fifth loop control signal Igridout_1 is calculated through an internal control loop, and the fifth loop control signal Igridout_1 is output to the DC-AC converter 13. The DC-AC converter 13 maintains the power-drawing current Igridfb_1 at the third target current Igridref_1, that is, the DC-AC converter operates in a constant current power-drawing mode.

[0149] The sixth loop control signal Ugridout_1 is generated by: the control unit 50 samples the bus voltage Ubus of the DC bus DC-BUS, and inputs the bus voltage Ubus and the fifth threshold voltage Uinvref_1 to the fourth voltage regulation loop controller G 6-1 (S), the fourth voltage regulation loop controller G 6-1 (S) According to the difference between the fifth threshold voltage Uinvref_1 and the bus voltage Ubus, the sixth loop control signal Ugridout_1 is calculated through the internal control loop, and the sixth loop control signal Ugridout_1 is output to the DC-AC converter 13. The DC-AC converter 13 maintains the bus voltage Ubus of the DC bus DC-BUS at the fifth threshold voltage Uinvref_1, that is, the DC-AC converter operates in a voltage-stabilized power supply mode.

[0150] After generating the fifth loop control signal Igridout_1 and the sixth loop control signal Ugridout_1 , the control unit 50 selects one of the two loop control signals with a smaller signal duty cycle and outputs it to the inverter circuit.

[0151] In the above embodiment, when the inverter circuit is in working state, the AC power supply 40 absorbs energy from the DC bus DC-BUS. For example, the energy absorbed by the AC power supply 40 is provided by the DC power supply 20, or the energy absorbed by the AC power supply 40 is provided by the battery module 20, or the energy absorbed by the AC power supply 40 is provided by the DC power supply 20 and the battery module 30. If the energy absorbed by the AC power supply 40 is less than the energy provided by the DC power supply 20 and / or the battery module 30, the bus voltage Ubus will increase. When the bus voltage Ubus is high, the difference between the fifth threshold voltage Uinvref_1 and the bus voltage Ubus is large, so the signal duty ratio of the sixth loop control signal Ugridout_1 is relatively large, and the control unit 50 selects the fifth loop control signal Igridout_1 to output to the inverter circuit. At this time, the DC-AC converter 13 operates in a constant current power supply mode.

[0152] When the energy provided by the DC power supply 20 and / or the battery module 30 is less than the energy absorbed by the AC power supply 40, the bus voltage Ubus of the DC bus DC-BUS will gradually decrease. As the bus voltage Ubus decreases, the difference between the bus voltage Ubus and the fifth threshold voltage Uinvref_1 also gradually decreases. When the bus voltage Ubus decreases to a value close to or equal to the fifth threshold voltage Uinvref_1, the signal duty cycle of the sixth loop control signal Ugridout_1 is less than the signal duty cycle of the fifth loop control signal Igridout_1, and the signal received by the inverter circuit is switched to the sixth loop control signal Ugridout_1. At this time, the working mode of the DC-AC converter is switched from the constant current power supply mode to the voltage stabilization power supply mode.

[0153] When the energy provided by the DC power supply 20 and / or the AC power supply 40 gradually increases and is greater than the energy absorbed by the AC power supply 40, the bus voltage Ubus of the DC bus DC-BUS will gradually increase, and the signal duty cycle of the sixth loop control signal Ugridout_1 will also gradually increase, so that the signal received by the inverter circuit is switched to the fifth loop control signal Igridout_1, and the working mode of the DC-AC converter 13 is switched from the voltage-stabilized power supply mode to the constant current power supply mode.

[0154] Please refer to Figure 5 and Fig.11When the power factor correction circuit of the DC-AC converter 13 is in operation, the control unit 50 controls the power factor correction circuit based on the discharge current Igridfb_2, the fourth target current Igridref_2 and the fourth constant current loop controller G 5-2 (S) Generate a fifth loop control signal Igridout_2, and based on the bus voltage Ubus of the DC bus DC-BUS, the sixth threshold voltage Upfcref_2 and the fifth voltage regulation loop controller G 6-2 (S) Generate a sixth loop control signal Ugridout_2.

[0155] The fourth target current Igridref_2 is the current when the DC-AC converter 13 operates in the constant current discharge mode, and the sixth threshold voltage Upfcref_2 is the voltage when the DC-AC converter 13 operates in the voltage stabilization discharge mode.

[0156] The fifth loop control signal Igridout_2 is generated as follows: after the control unit 50 obtains the discharge current Igridfb_2 of the power factor correction circuit by sampling the second current sensor, the discharge current Igridfb_2 and the fourth target current Igridref_2 are input into the fifth constant current loop controller. The fifth constant current loop controller obtains the fifth loop control signal Igridout_2 through internal control loop calculation based on the difference between the fourth target current Igridref_2 and the discharge current Igridfb_2, and outputs the fifth loop control signal Igridout_2 to the DC-AC converter 13. The DC-AC converter 13 maintains the discharge current Igridfb_2 at the fourth target current Igridref_2, that is, the DC-AC converter 13 operates in the constant current discharge mode.

[0157] The sixth loop control signal Ugridout_2 is generated by: the control unit 50 samples the bus voltage Ubus of the DC bus DC-BUS, and inputs the bus voltage Ubus and the sixth threshold voltage Upfcref_2 to the fifth voltage regulation loop controller G 6-2 (S), the fifth voltage regulation loop controller G 6-2 (S) According to the difference between the sixth threshold voltage Upfcref_2 and the bus voltage Ubus, the sixth loop control signal Ugridout_2 is calculated through the internal control loop, and the sixth loop control signal Ugridout_2 is output to the DC-AC converter 13. The DC-AC converter 13 maintains the bus voltage Ubus of the DC bus DC-BUS at the sixth threshold voltage Upfcref_2, that is, the DC-AC converter 13 operates in the voltage stabilization discharge mode.

[0158] After generating the fifth loop control signal Igridout_2 and the sixth loop control signal Ugridout_2, the control unit 50 selects one of the two loop control signals with a smaller signal duty cycle and outputs it to the power factor correction circuit.

[0159] In the above embodiment, when the power factor correction circuit of the DC-AC converter 13 is in working state, the AC power supply 40 provides energy to the DC bus DC-BUS. If the bus energy provided by the AC power supply 40 is lower than the bus energy absorbed by the battery module 30, the bus voltage Ubus will be reduced. When the bus voltage Ubus is low, the difference between the bus voltage Ubus and the sixth threshold voltage Upfcref_2 is large, so the signal duty ratio of the sixth loop control signal Ugridout_2 is relatively large, and the control unit 50 selects the fifth loop control signal Igridout_2 to output to the DC-AC converter 13, and the DC-AC converter 13 operates in a constant current discharge mode.

[0160] When the energy absorbed by the battery module 30 from the DC bus DC-BUS is less than the energy provided by the AC power supply 40, the bus voltage Ubus of the DC bus DC-BUS will gradually increase. As the bus voltage Ubus increases, the difference between the bus voltage Ubus and the sixth threshold voltage Upfcref_2 also gradually decreases. When the bus voltage Ubus increases to a value close to or equal to the sixth threshold voltage Upfcref_2, the signal duty cycle of the sixth loop control signal Ugridout_2 will be less than the signal duty cycle of the fifth loop control signal Igridout_2, and the signal received by the DC-AC converter 13 is switched to the sixth loop control signal Ugridout_2. At this time, the working mode of the DC-AC converter 13 is switched from the constant current discharge mode to the voltage stabilization discharge mode.

[0161] Based on the above embodiments, when the power conversion unit 10 is connected to multiple energy input and output modules (DC power supply 20, battery module 30 and AC power supply 30), the input and output of energy converge at the DC bus DC-BUS, and there are multiple combinations of energy flows at the DC bus DC-BUS. In the above embodiments, by respectively setting each sub-power converter (first DC-DC converter 11, second DC-DC converter 12, DC-AC converter 13) in the power conversion unit 10 to correspond to different voltage stabilization point voltages at the DC bus DC-BUS, the decoupling of complex energy distribution at the DC bus DC-BUS is achieved. When a sub-power converter operates in constant current mode, the loop control signal corresponding to the constant current mode is used to make it operate in constant current mode to achieve constant current charging or constant current discharging. For example, during the charging process of the battery module 30, the voltage stabilization point voltage of the DC bus DC-BUS is the third threshold voltage Ubatref_1. If the energy provided by other modules to the DC bus DC-BUS can meet the energy absorption demand of the battery module 30, the sub-power converter electrically connected to the battery module 30 operates in a constant current charging mode, and the bus voltage Ubus of the DC bus DC-BUS is controlled by other sub-power converters, that is, at this time, the bus voltage Ubus is far away from the third threshold voltage Ubatref_1. During the discharge process of the battery module 30, the voltage stabilization point voltage of the DC bus DC-BUS is the fourth threshold voltage Ubatref_2. By setting the fourth threshold voltage Ubatref_2 higher than the fifth threshold voltage Uinvref_1 when the AC power supply 40 draws power, when the energy provided by the battery module 30 is greater than the energy absorbed by the AC power supply 40, the bus voltage Ubus is maintained at the fourth threshold voltage Ubatref_2. At this time, the sub-power converter electrically connected to the AC power supply 40 operates in a constant current power-drawing mode. On the contrary, if the energy provided by the battery module 30 is less than the energy absorbed by the AC power supply 40, the bus voltage Ubus will drop to the fifth threshold voltage Uinvref_1. At this time, the sub-power converter electrically connected to the AC power supply 40 operates in a voltage stabilization power supply mode, and the sub-power converter electrically connected to the battery module 30 operates in a constant current discharge mode.

[0162] According to some embodiments of the present application, the magnitude relationship among the second threshold voltage Upvref_2, the third threshold voltage Ubatref_1, the fourth threshold voltage Ubatref_2, the fifth threshold voltage Uinvref_1 and the sixth threshold voltage Upfcref_2 is:

[0163] Upvref_2>Ubatref_2>Uinvref_1=Upfcref_2>Ubatref_1; or,

[0164] Upvref_2>Ubatref_2>Ubatref_1>Uinvref_1=Upfcref_2.

[0165] As an optional embodiment, when the bus voltage Ubus is close to Upvref_2, the first DC-DC converter 11 electrically connected to the DC power supply 20 operates in a voltage regulation mode, and the second DC-DC converter 12 electrically connected to the battery module 30 and / or the DC-AC converter 13 electrically connected to the AC power supply 40 operates in a constant current mode.

[0166] When the battery module 30 is charged and absorbs energy, if the bus voltage Ubus is close to Ubatref_1 or the difference between the two is small, the second DC-DC converter 12 electrically connected to the battery module 30 operates in a regulated charging mode, and the first DC-DC converter 11 electrically connected to the DC power supply 20 and / or the DC-AC converter 13 electrically connected to the AC power supply 40 operates in a constant current mode.

[0167] When the battery module 30 discharges to provide energy to the outside, if the bus voltage Ubus is close to Ubatref_2, the second DC-DC converter 12 electrically connected to the battery module 30 operates in a voltage-stabilized discharge mode, and the DC-AC converter 13 electrically connected to the AC power supply 40 operates in a constant current mode.

[0168] When the AC power supply 40 draws electricity from the outside to absorb energy, if the bus voltage Ubus is close to Uinvref_1, the DC-AC converter 13 electrically connected to the AC power supply 40 operates in a voltage-stabilized power supply mode, and the second DC-DC converter 12 electrically connected to the battery module 30 and / or the first DC-DC converter 11 electrically connected to the DC power supply 20 operates in a constant current mode.

[0169] When the AC power supply 40 discharges to provide energy, if the bus voltage Ubus is close to Upfcref_2, the DC-AC converter 13 electrically connected to the AC power supply 40 operates in a voltage-stabilized discharge mode, and the second DC-DC converter 12 electrically connected to the battery module 30 operates in a constant current mode.

[0170] In the above two magnitude relationships, the second threshold voltage Upvref_2 is set to the maximum threshold voltage from the second threshold voltage to the sixth threshold voltage. When the second DC-DC converter 12 operates in the voltage-regulated charging mode or the DC-AC converter operates in the voltage-regulated power-taking mode, since the voltage difference between the bus voltage Ubus and the second threshold voltage Upvref_2 is large at this time, the signal duty cycle of the second loop control signal Upvout_2 is greater than the first loop control signal Upvout_1. When the energy absorbed by the battery module 30 and / or the AC power supply 40 is less than the energy provided by the DC power supply 20, the bus voltage Ubus gradually increases due to the energy redundancy on the DC bus. When the bus voltage Ubus increases to close to the second threshold voltage Upvref_2, the first DC-DC converter 11 switches to the voltage-regulated mode. That is, within the voltage allowable range of the bus voltage Ubus, the DC power supply 20 is operated in the maximum power point tracking mode as much as possible.

[0171] In the above two size relationships, the first size relationship satisfies Ubatref_2>Uinvref_1=Upfcref_2>Ubatref_1. That is, when the battery module 30 is charged, the voltage stabilization point voltage Ubatref_1 of the second DC-DC converter 12 working in the voltage stabilization charging mode is less than the voltage stabilization point voltage Upfcref_2 of the power factor correction circuit. When the energy provided by the AC power supply 40 is greater than or equal to the energy absorbed by the battery module 30, the bus voltage Ubus is pulled up to Upfcref_2, so that the DC-AC converter 13 works in the voltage stabilization discharge mode, and the second DC-DC converter 12 works in the constant current charging mode to achieve maximum current charging. When the battery module 30 is discharging, the stabilization point voltage Ubatref_2 of the second DC-DC converter 12 working in the stabilization discharge mode is greater than the stabilization point voltage Uinvref_1 of the inverter circuit. When the energy provided by the battery module 30 is greater than or equal to the energy absorbed by the AC power supply 40, the bus voltage Ubus is raised to Ubatref_2, so that the second DC-DC converter 12 works in the stabilization discharge mode and the DC-AC converter 13 works in the constant current power supply mode.

[0172] In the above embodiment, if the energy provided to the DC bus DC-BUS is greater than the energy absorbed from the DC bus DC-BUS, the module providing energy operates in a voltage stabilization mode, and the module absorbing energy operates in a constant current mode; if the energy provided to the DC bus DC-BUS is less than the energy absorbed from the DC bus DC-BUS, the module providing energy operates in a constant current mode, and the module absorbing energy operates in a voltage stabilization mode;

[0173] In the second magnitude relationship, Ubatref_2>Ubatref_1>Uinvref_1=Upfcref_2. In order to ensure that the energy of the DC power supply 20 is preferentially provided to the AC power supply 30 to supply power to the load and to prevent the second DC-DC converter 12 from drawing power from the AC power supply 30, Ubatref_1>Uinvref_1 is set.

[0174] In the above embodiment of the present application, the power conversion unit 10 is electrically connected to two of the multiple energy input and output modules (DC power supply 20, battery module 30 and AC power supply 30) as an example. One module provides energy and the other module absorbs energy.

[0175] When the energy provided by the energy-providing module is greater than the energy absorbed by the energy-absorbing module, the sub-power converter (first DC-DC converter 11, second DC-DC converter 12 or DC-AC converter 13) connected to the energy-absorbing module operates in constant current mode, and the sub-power converter connected to the energy-providing module operates in voltage stabilization mode. At this time, the energy-absorbing module absorbs energy according to normal power, and the sub-power converter connected to the energy-providing module provides energy with the corresponding threshold voltage in voltage stabilization mode as the target value of the bus voltage. When the bus voltage reaches the corresponding threshold voltage in voltage stabilization mode or approaches the threshold voltage, the energy provided is close to the absorbed energy, so that the bus voltage is maintained within a stable voltage range. The sub-power converter operates in voltage stabilization mode to avoid excessive power provided by the energy-providing module, which may cause overvoltage of the bus voltage.

[0176] When the energy provided by the energy-providing module is less than the energy absorbed by the energy-absorbing module, the sub-power converter (first DC-DC converter 11, second DC-DC converter 12 or DC-AC converter 13) connected to the energy-providing module operates in constant current mode, and the sub-power converter connected to the energy-absorbing module operates in voltage stabilization mode. At this time, the energy-providing module provides energy according to normal power, and the sub-power converter corresponding to the energy-absorbing module absorbs energy with the corresponding threshold voltage in the voltage stabilization mode as the target value of the bus voltage. When the bus voltage reaches the corresponding threshold voltage in the voltage stabilization mode or is close to the threshold voltage, the energy provided is close to the absorbed energy, so that the bus voltage is maintained within a stable voltage range. By operating the sub-power converter in voltage stabilization mode, it is avoided that the energy-providing module absorbs too much power and causes undervoltage of the bus voltage.

[0177] In another optional embodiment, take the three electrical connections between the power conversion unit 10 and multiple energy input and output modules (DC power supply 20, battery module 30 and AC power supply 30) as an example. The three modules are respectively connected to three sub-power converters, one of which works in a voltage regulation mode so that the bus voltage approaches the voltage regulation point voltage corresponding to the voltage regulation mode of the sub-power converter, and the other two sub-power converters work in a constant current mode / maximum power point mode. By setting multiple threshold voltages as the voltage regulation point voltages of each sub-power converter in different working modes, when the multiple threshold voltages are all within the normal voltage range of the bus voltage, the bus voltage approaches a certain threshold voltage or is maintained in a voltage range to avoid overvoltage or undervoltage of the bus voltage.

[0178] Power distribution method

[0179] Based on the energy storage and conversion equipment provided in the above embodiments, the present application also provides an electric energy distribution method accordingly. Please refer to the following embodiments.

[0180] Please refer to Fig.12 , the electric energy distribution method provided in the embodiment of the present application includes:

[0181] S110, collecting the output voltage of the DC power supply and the bus voltage of the DC bus;

[0182] S120, calculating a first voltage difference between a first threshold voltage of the DC power supply and an output voltage of the DC power supply, and a second voltage difference between a second threshold voltage and a bus voltage;

[0183] S130, calculating a first loop control signal corresponding to the first voltage difference based on a control algorithm of a maximum power loop controller, and calculating a second loop control signal corresponding to the second voltage difference based on a control algorithm of a first voltage regulation loop controller;

[0184] S140, comparing the signal duty cycles of the first loop control signal and the second loop control signal, and outputting the first loop control signal or the second loop control signal having the smaller signal duty cycle to the power conversion unit.

[0185] In this embodiment, after collecting the output voltage of the DC power supply and the bus voltage of the DC bus, a first loop control signal is generated based on the first voltage difference between the output voltage and the first threshold voltage. And based on the difference between the bus voltage and the second threshold voltage, a second loop control signal is generated. After generating the first loop control signal and the second loop control signal, one of the two loop control signals with a smaller signal duty cycle is output to the power conversion unit. When the signal duty cycle of a certain loop control signal is reduced from higher than another loop control signal to lower than another loop control signal, the output switching of the loop control signal can be realized, and then the working mode switching of the DC power supply can be realized to maintain the energy balance in the energy storage and conversion device. In the above process, there is no need for software logic operation, and the control unit can realize the switching of the working mode by comparing and analyzing the signal duty cycle.

[0186] The specific implementation methods of the above steps are introduced below.

[0187] In S110, when the power conversion unit in the energy storage and conversion device is electrically connected to the DC power supply, the output voltage of the DC power supply and the bus voltage of the DC bus are collected by the control unit.

[0188] In S120, taking the DC power supply as a photovoltaic module as an example, the first threshold voltage of the DC power supply is the MPPT (Maximum Power Point Tracking) voltage of the photovoltaic module. When the output voltage of the DC power supply is the first threshold voltage, the DC power supply outputs the maximum power to provide energy to the DC bus.

[0189] After the first threshold voltage is calculated using the maximum power point algorithm, the calculated first threshold voltage is subtracted from the collected output voltage of the direct current power supply to obtain a first voltage difference.

[0190] The control unit also obtains a second threshold voltage, which is a voltage stabilization point voltage corresponding to the first DC-DC converter operating in a voltage stabilization mode, and subtracts the collected bus voltage of the DC bus from the second threshold voltage to obtain a second voltage difference.

[0191] In S130, after obtaining the first voltage difference, a first loop control signal is calculated based on the first voltage difference according to a control algorithm of the maximum power loop controller. After the first loop control signal is output to the power conversion unit, the first DC-DC converter is controlled to operate in a maximum power point mode.

[0192] After obtaining the second voltage difference, a second loop control signal is obtained based on the second voltage difference based on the control algorithm of the first voltage regulation loop controller. After the second loop control signal is output to the power conversion unit, the first DC-DC converter is controlled to operate in a voltage regulation mode.

[0193] In S140 , after obtaining the first loop control signal and the second loop control signal, the duty cycles of the two loop control signals are compared, and the signal with the smaller duty cycle is output to the power conversion unit.

[0194] In the above embodiment, since the control unit generates two loop control signals in real time and selects one of them to be output to the power conversion unit. When the signal duty cycle of a certain loop control signal is reduced to be lower than that of another loop control signal, the output switching of the loop control signal can be realized, and then the working mode switching of the first DC-DC converter can be realized to maintain the energy balance in the energy storage and conversion device. In the above process, there is no need for software logic operation, and the control unit can realize the switching of the working mode of the first DC-DC converter by comparing and analyzing the signal duty cycle.

[0195] Please refer to Fig.13 The present application also provides an electric energy distribution method. The electric energy distribution method also includes:

[0196] S210, collecting the charging current or discharging current of the battery module and the bus voltage of the DC bus;

[0197] S220, calculating a current error value of the second DC-DC converter in a constant current mode based on a charging current or a discharging current of the battery module; and calculating a voltage error value of the second DC-DC converter in a voltage regulation mode based on a bus voltage;

[0198] S230, calculating a third loop control signal corresponding to the current error value based on a control algorithm corresponding to the second DC-DC converter being in a constant current mode, and calculating a fourth loop control signal corresponding to the voltage error value based on a control algorithm corresponding to the second DC-DC converter being in a voltage regulation mode;

[0199] S240, comparing the signal duty cycles of the third loop control signal and the fourth loop control signal, and outputting the one with the smaller signal duty cycle between the third loop control signal and the fourth loop control signal to the power conversion unit.

[0200] In this embodiment, after collecting the charging current or discharging current based on the charging and discharging mode of the second DC-DC converter, the current error value is calculated according to the charging current or the discharging current, and the voltage error value is calculated according to the collected bus voltage. The third loop control signal corresponding to the current error value is calculated based on the control algorithm of the second DC-DC converter in the constant current mode, and the fourth loop control signal corresponding to the voltage error value is calculated based on the control algorithm of the second DC-DC converter in the voltage stabilization mode. After generating the third loop control signal and the fourth loop control signal, the one with the smaller signal duty cycle of the two loop control signals is output to the power conversion unit. When the signal duty cycle of a certain loop control signal is reduced from higher than that of another loop control signal to lower than that of another loop control signal, the output switching of the loop control signal can be realized, and then the working mode switching of the second DC-DC converter can be realized to maintain the energy balance in the energy storage and conversion device. In the above process, there is no need to perform software logic operations, and the control unit can compare and analyze the signal duty cycle to realize the switching of the working mode of the second DC-DC converter.

[0201] In S210, when the power conversion unit in the energy storage and conversion device is electrically connected to the battery module, the charging current or discharging current of the battery module and the bus voltage of the DC bus are collected by the control unit.

[0202] It should be noted that the above-mentioned collection of the charging current or discharging current of the battery module and the bus voltage of the DC bus means that when the second DC-DC converter is in the charging mode, the charging current of the second DC-DC converter and the bus voltage of the DC bus are collected; when the second DC-DC converter is in the discharging mode, the discharge current of the second DC-DC converter and the bus voltage of the DC bus are collected.

[0203] In S220, when the second DC-DC converter is in the charging mode, the current error value of the second DC-DC converter in the constant current mode is calculated based on the charging current of the second DC-DC converter. When the second DC-DC converter is in the discharging mode, the current error value of the second DC-DC converter in the constant current mode is calculated based on the discharging current of the second DC-DC converter. Based on the bus voltage of the DC bus, the voltage error value of the second DC-DC converter in the voltage regulation mode is calculated.

[0204] According to some embodiments of the present application, the above-mentioned calculation of the current error value of the second DC-DC converter in the constant current mode based on the charging current or the discharging current of the second DC-DC converter includes:

[0205] S310, in response to the second DC-DC converter operating in the charging mode, calculating a first current difference between a charging current of the battery module and a first target current in the constant current charging mode;

[0206] and / or,

[0207] S320, in response to the second DC-DC converter operating in the discharge mode, calculating a second current difference between the discharge current of the battery module and the second target current in the constant current discharge mode;

[0208] Based on the bus voltage, a voltage error value of the second DC-DC converter in a voltage regulation mode is calculated, including:

[0209] S330, in response to the second DC-DC converter operating in the charging mode, calculating a third voltage difference between a third threshold voltage and the bus voltage;

[0210] and / or,

[0211] S340 , in response to the second DC-DC converter operating in the discharge mode, calculating a fourth voltage difference between a fourth threshold voltage and the bus voltage.

[0212] In this embodiment, according to the working mode of the second DC-DC converter, the current difference and the voltage difference in the charging mode, or the current difference and the voltage difference in the discharging mode are calculated respectively.

[0213] In S310, when the second DC-DC converter operates in the charging mode, the battery module is in a charging state and absorbs energy from the DC bus. At this time, the charging current of the battery module is collected, and the charging current is subtracted from the first target current corresponding to the constant current charging mode to obtain a first current difference.

[0214] In S320, when the second DC-DC converter operates in the discharge mode, the battery module is in a discharge state and provides energy to the DC bus. At this time, the discharge current of the battery module is collected, and the discharge current is subtracted from the corresponding second target current in the constant current discharge mode to obtain a second current difference.

[0215] It should be noted that in the above-mentioned embodiment of the energy storage converter, the second DC-DC converter is a unidirectional DC-DC converter or a bidirectional DC-DC converter. When the second DC-DC converter is a bidirectional DC-DC converter, the second DC-DC converter works in the charging mode and also in the discharging mode. When the second DC-DC converter is a unidirectional DC-DC converter, the second DC-DC converter can only work in one of the charging mode or the discharging mode.

[0216] In S330, when the second DC-DC converter operates in the charging mode, the battery module is in a charging state and absorbs energy from the DC bus. At this time, a third threshold voltage is obtained, and the third threshold voltage is the voltage stabilization point voltage of the battery module in the voltage stabilization charging mode. The third voltage difference can be obtained by subtracting the third threshold voltage from the bus voltage.

[0217] In S340, when the second DC-DC converter operates in the discharge mode, the battery module is in a discharge state and provides energy to the DC bus. At this time, a fourth threshold voltage is obtained, and the fourth threshold voltage is the voltage stabilization point voltage of the battery module in the voltage stabilization discharge mode. The fourth voltage difference can be obtained by subtracting the fourth threshold voltage from the bus voltage.

[0218] In S230, after obtaining the current error value, a third loop control signal is calculated based on a control algorithm corresponding to the second DC-DC converter being in a constant current mode. After obtaining the voltage error value, a fourth loop control signal is calculated based on a control algorithm corresponding to the second DC-DC converter being in a voltage regulation mode.

[0219] According to some embodiments of the present application, the above-mentioned calculation of the third loop control signal corresponding to the current error value based on the control algorithm corresponding to the second DC-DC converter being in the constant current mode includes:

[0220] S410, in response to the second DC-DC converter operating in the charging mode, calculating a third loop control signal corresponding to the first current difference based on a control algorithm of the first constant current loop controller;

[0221] and / or,

[0222] S420, in response to the second DC-DC converter operating in the discharge mode, calculating a third loop control signal corresponding to the second current difference based on a control algorithm of the second constant current loop controller;

[0223] The above-mentioned calculation of the fourth loop control signal corresponding to the voltage error value based on the control algorithm corresponding to the second DC-DC converter being in the voltage regulation mode includes:

[0224] S430, in response to the second DC-DC converter operating in the charging mode, calculating a fourth loop control signal corresponding to the third voltage difference based on a control algorithm of the second voltage regulation loop controller;

[0225] S440 , in response to the second DC-DC converter operating in the discharge mode, based on the control algorithm of the third voltage regulation loop controller, calculating a fourth loop control signal corresponding to the fourth voltage difference.

[0226] In this embodiment, according to the working mode of the second DC-DC converter, based on the current difference and the voltage difference, the corresponding constant current loop controller and the voltage stabilizing loop controller are used to generate the third loop control signal and the fourth loop control signal.

[0227] In S410, when the second DC-DC converter operates in the charging mode, the battery module is in a charging state and absorbs energy from the DC bus. Based on the control algorithm of the first constant current loop controller, a third loop control signal corresponding to the first current difference is calculated.

[0228] In S420, when the second DC-DC converter operates in the discharge mode, the battery module is in a discharge state and provides energy to the DC bus. Based on the control algorithm of the second constant current loop controller, a third loop control signal corresponding to the second current difference is calculated.

[0229] In S430, when the second DC-DC converter operates in the charging mode, the battery module is in a charging state and absorbs energy from the DC bus. Based on the control algorithm of the second voltage regulation loop controller, a fourth loop control signal corresponding to the third voltage difference is calculated.

[0230] In S440, when the second DC-DC converter operates in the discharge mode, the battery module is in a discharge state and provides energy to the DC bus. Based on the control algorithm of the third voltage stabilizing loop controller, a fourth loop control signal corresponding to the fourth voltage difference is calculated.

[0231] In S240, after the third loop control signal and the fourth loop control signal are generated, the signal duty cycles of the third loop control signal and the fourth loop control signal are compared, and the loop control signal with the smaller signal duty cycle is selected to be output to the power conversion unit.

[0232] Please refer to Fig.14 The present application also provides a method for distributing electric energy. The above-mentioned method for distributing electric energy also includes:

[0233] S510, collecting the power supply current or discharge current of the AC power supply and the bus voltage of the DC bus;

[0234] S520, calculating a current error value of the DC-AC converter in a constant current mode based on a power-drawing current or a discharge current of the AC power source; and calculating a voltage error value of the DC-AC converter in a voltage stabilization mode based on a bus voltage;

[0235] S530, calculating a fifth loop control signal corresponding to the current error value based on a control algorithm corresponding to the DC-AC converter being in a constant current mode, and calculating a sixth loop control signal corresponding to the voltage error value based on a control algorithm corresponding to the DC-AC converter being in a voltage regulation mode;

[0236] S540, comparing the signal duty cycles of the fifth loop control signal and the sixth loop control signal, and outputting the one with the smaller signal duty cycle between the fifth loop control signal and the sixth loop control signal to the power conversion unit.

[0237] In this embodiment, after collecting the power-taking current or the discharge current based on the power-taking mode or the discharge mode of the DC-AC converter, the current error value is calculated according to the power-taking current or the discharge current, and the voltage error value is calculated according to the collected bus voltage. The fifth loop control signal corresponding to the current error value is calculated based on the control algorithm in the constant current mode, and the sixth loop control signal corresponding to the voltage error value is calculated based on the control algorithm in the voltage stabilization mode. After generating the fifth loop control signal and the sixth loop control signal, the one with the smaller signal duty cycle of the two loop control signals is output to the power conversion unit. When the signal duty cycle of a certain loop control signal is reduced from higher than that of another loop control signal to lower than that of another loop control signal, the output switching of the loop control signal can be realized, and then the working mode switching of the DC-AC converter can be realized to maintain the energy balance in the energy storage and conversion equipment. In the above process, there is no need for software logic operation, and the control unit can realize the switching of the working mode of the DC-AC converter by comparing and analyzing the signal duty cycle.

[0238] In S510, when the power conversion unit in the energy storage and conversion device is electrically connected to the AC power source, the power intake current or discharge current of the AC power source and the bus voltage of the DC bus are collected by the control unit.

[0239] It should be noted that the above-mentioned acquisition of the power-drawing current or discharge current of the AC power supply and the bus voltage of the DC bus refers to the acquisition of the power-drawing current of the DC-AC converter and the bus voltage of the DC bus when the DC-AC converter is in the power-drawing mode; the acquisition of the discharge current of the DC-AC converter and the bus voltage of the DC bus when the DC-AC converter is in the discharge mode;

[0240] In S520, when the DC-AC converter is in the power-drawing mode, the current error value of the AC power supply in the constant current mode is calculated based on the power-drawing current. When the DC-AC converter is in the discharge mode, the current error value of the DC-AC converter in the constant current mode is calculated based on the discharge current. Based on the bus voltage of the DC bus, the voltage error value in the voltage regulation mode is calculated.

[0241] According to some embodiments of the present application, based on the power supply current or discharge current of the DC-AC converter, calculating the current error value of the DC-AC converter in a constant current mode includes:

[0242] S610, in response to the inverter circuit being in a working state, calculating a third current difference between a power supply current of the AC power supply and a third target current in a constant current power supply mode;

[0243] and / or,

[0244] S620, in response to the power factor correction circuit being in an operating state, calculating a fourth current difference between a discharge current of the AC power source and a fourth target current in a constant current discharge mode;

[0245] Based on the bus voltage, the voltage error value of the DC-AC converter in the voltage regulation mode is calculated, including:

[0246] S630, in response to the inverter circuit being in an operating state, calculating a fifth voltage difference between a fifth threshold voltage and the bus voltage;

[0247] and / or,

[0248] S640, in response to the power factor correction circuit being in an operating state, calculating a sixth voltage difference between a sixth threshold voltage and the bus voltage.

[0249] In this embodiment, according to the working states of the inverter circuit and the power factor correction circuit, the current difference and the voltage difference in the power-taking mode, or the current difference and the voltage difference in the discharge mode are calculated respectively.

[0250] In S610, when the inverter circuit is in working state, the AC power supply is in power-drawing state, absorbing energy from the DC bus. At this time, the power-drawing current of the AC power supply is collected, and the difference between the power-drawing current and the third target current in the constant current power-drawing mode is calculated to obtain the third current difference.

[0251] In S620, when the power factor correction circuit is in the working state, the AC power supply is in the discharging state and provides energy to the DC bus. At this time, the discharge current of the AC power supply is collected, and the difference between the discharge current and the fourth target current in the constant current discharge mode is calculated to obtain a fourth current difference.

[0252] It should be noted that in the above-mentioned embodiment of the energy storage converter, the DC-AC converter includes a unidirectional DC-AC converter or a bidirectional DC-AC converter. The unidirectional DC-AC converter includes an inverter circuit, and the bidirectional DC-AC converter includes an inverter circuit and a power factor correction circuit. Therefore, when the DC-AC converter includes a unidirectional DC-AC converter, only the inverter circuit can be in a working state; when the DC-AC converter includes a bidirectional DC-AC converter, it is the inverter circuit that is in a working state, and it is also the power factor correction circuit that is in a working state.

[0253] In S630, when the inverter circuit is in the working state, the AC power supply is in the power-drawing state, absorbing energy from the DC bus. At this time, the fifth threshold voltage is obtained, and the fifth threshold voltage is the voltage of the voltage stabilization point of the AC power supply in the voltage stabilization power-drawing mode. The difference between the fifth threshold voltage and the bus voltage is calculated to obtain a fifth voltage difference.

[0254] In S640, when the power factor correction circuit is in the working state, the AC power supply is in the discharging state and provides energy to the DC bus. At this time, a sixth threshold voltage is obtained, and the sixth threshold voltage is the voltage of the stabilizing point of the AC power supply in the voltage stabilizing discharge mode. The difference between the sixth threshold voltage and the bus voltage is calculated to obtain a sixth voltage difference.

[0255] In S530, after obtaining the current error value, a fifth loop control signal is calculated based on a control algorithm corresponding to the DC-AC converter being in a constant current mode. After obtaining the voltage error value, a sixth loop control signal is calculated based on a control algorithm corresponding to the DC-AC converter being in a voltage stabilization mode.

[0256] According to some embodiments of the present application, based on a control algorithm corresponding to the DC-AC converter being in a constant current mode, calculating a fifth loop control signal corresponding to the current error value includes:

[0257] S710, in response to the inverter circuit being in a working state, calculating a fifth loop control signal corresponding to the third current difference based on a control algorithm of the third constant current loop controller;

[0258] and / or,

[0259] S720, in response to the power factor correction circuit being in an operating state, calculating a fifth loop control signal corresponding to the fourth current difference based on a control algorithm of the fourth constant current loop controller;

[0260] Based on a control algorithm corresponding to the DC-AC converter being in a voltage regulation mode, a sixth loop control signal corresponding to the voltage error value is calculated, including:

[0261] S730, in response to the inverter circuit being in a working state, calculating a sixth loop control signal corresponding to the fifth voltage difference based on a control algorithm of the fourth voltage stabilization loop controller;

[0262] and / or,

[0263] S740, in response to the power factor correction circuit being in the working state, based on the control algorithm of the fifth voltage regulation loop controller, calculating a sixth loop control signal corresponding to the sixth voltage difference.

[0264] In this embodiment, according to the working status of the inverter circuit and the power factor correction circuit, based on the current difference and the voltage difference, the corresponding constant current loop controller and the voltage stabilizing loop controller are used to generate the fifth loop control signal and the sixth loop control signal.

[0265] In S610, when the inverter circuit is in the working state, the AC power supply is in the power-drawing state, absorbing energy from the DC bus. Based on the control algorithm of the third constant current loop controller, a fifth loop control signal corresponding to the third current difference is calculated.

[0266] In S620, when the power factor correction circuit is in the working state, the AC power supply is in the discharging state, providing energy to the DC bus. Based on the control algorithm of the fourth constant current loop controller, a fifth loop control signal corresponding to the fourth current difference is calculated.

[0267] In S630, when the inverter circuit is in the working state, the AC power supply is in the power-drawing state, absorbing energy from the DC bus. Based on the control algorithm of the fourth voltage stabilizing loop controller, a sixth loop control signal corresponding to the fifth voltage difference is calculated.

[0268] In S640, when the power factor correction circuit is in the working state, the AC power supply is in the discharging state, providing energy to the DC bus. Based on the control algorithm of the fifth voltage stabilizing loop controller, a sixth loop control signal corresponding to the sixth voltage difference is calculated.

[0269] In S540, after the fifth loop control signal and the sixth loop control signal are generated, the signal duty cycles of the fifth loop control signal and the sixth loop control signal are compared, and the loop control signal with the smaller signal duty cycle is selected to be output to the power conversion unit.

[0270] Electronic devices

[0271] Fig.15 The hardware structure diagram of the electronic device provided in the embodiment of the present application is shown. The electronic device is at least one of a computer, a server and a document generation dedicated device. The electronic device includes a processor 1501 and a memory 1502 storing computer program instructions.

[0272] Specifically, the processor 1501 includes a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or is configured to implement one or more integrated circuits of the embodiments of the present application.

[0273] Memory 1502 includes a large capacity memory for data or instructions. By way of example and not limitation, memory 1502 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 1502 may include a removable or non-removable (or fixed) medium. Where appropriate, memory 1502 may be inside or outside the electronic device. In a particular embodiment, memory 1502 is a non-volatile solid-state memory.

[0274] The memory 1502 may include a read-only memory (ROM), a flash memory device, a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, an electrical, optical or other physical / tangible memory storage device. Thus, typically, the memory 1502 includes a tangible (non-transitory) computer-readable storage medium (e.g., a memory device) of one or more software that is encoded with computer-executable instructions and that, when executed (e.g., by one or more processors), is operable to perform the operations described with reference to the methods according to the above aspects of the present disclosure.

[0275] The processor 1501 implements any one of the power distribution methods in the above embodiments by reading and executing computer program instructions stored in the memory 1502 .

[0276] In one example, the electronic device may further include a communication interface 1503 and a bus 1510. Fig.15 As shown, the processor 1501, the memory 1502, and the communication interface 1503 are connected via a bus 1510 and communicate with each other.

[0277] The communication interface 1503 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0278] Bus 1510 includes hardware, software or both, and the parts of electronic equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 1510 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0279] The electronic device is based on a method of distributing electrical energy, thereby combining Fig.12 and Fig.14 Describe the method of distributing electrical energy.

[0280] In addition, in combination with the power distribution method in the above embodiments, the present application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any one of the power distribution methods in the above embodiments is implemented.

[0281] In addition, an embodiment of the present application also provides a computer program product, including a computer program, which can implement the steps and corresponding contents of the aforementioned method embodiment when executed by a processor.

[0282] It should be understood that the terms and expressions used herein are for description only, and one or more embodiments of this specification should not be limited to these terms and expressions. The use of these terms and expressions does not mean to exclude any equivalent features of the schematics and descriptions (or parts thereof), and it should be recognized that various modifications that may exist should also be included in the scope of the claims. Other modifications, changes and substitutions may also exist. Accordingly, the claims should be deemed to cover all such equivalents.

Claims

1. An energy storage and current conversion device, characterized in that: include: DC bus (DC-BUS); A power conversion unit (10) is electrically connected to the DC bus (DC-BUS), and the power conversion unit is configured to be electrically connected to a plurality of the DC power source (20), the battery module (30), and the AC power source (40); A control unit is electrically connected to the power conversion unit (10), and the control unit is configured to perform the following operations: Outputting one of the first loop control signal and the second loop control signal to the power conversion unit (10); and / or, Outputting one of the third loop control signal and the fourth loop control signal to the power conversion unit (10); and / or, outputting one of the fifth loop control signal and the sixth loop control signal to the power conversion unit (10); The first loop control signal is generated based on the output voltage (Upvfb) of the DC power supply (20) and a first threshold voltage (Upvref_1); the second loop control signal is generated based on the bus voltage (Ubus) of the DC bus (DC-BUS) and a second threshold voltage (Upvref_2); the third loop control signal is generated based on the charging current (Ibatfb_1) of the power conversion unit (10) and a first target current (Ibatref_1), or based on the discharging current (Ibatfb_2) of the power conversion unit (10) and a second target current (Ibatref_2); the fourth loop control signal is generated based on the third threshold voltage (Ubatref_1 ) or one of the fourth threshold voltages (Ubatref_2), and the bus voltage (Ubus) of the DC bus (DC-BUS); the fifth loop control signal is generated based on the power-intake current (Igridfb_1) of the power conversion unit (10) and the third target current (Igridref_1), or, based on the discharge current (Igridfb_2) of the power conversion unit (10) and the fourth target current (Igridref_2); the sixth loop control signal is generated based on one of the fifth threshold voltage (Uinvref_1) or the sixth threshold voltage (Upfcref_2), and the bus voltage (Ubus) of the DC bus (DC-BUS).

2. The energy storage and conversion device according to claim 1, characterized in that: The power conversion unit (10) comprises: A first DC-DC converter (11) is configured to be disposed between the DC power supply (20) and the DC bus (DC-BUS), and the control unit is configured to output one of a first loop control signal and a second loop control signal to the first DC-DC converter (11); and / or, A second DC-DC converter (12) is configured to be disposed between the battery module (30) and the DC bus (DC-BUS), and the control unit is configured to output one of the third loop control signal and the fourth loop control signal to the second DC-DC converter (12); and / or, The DC-AC converter (13) is configured to be arranged between the AC power source (40) and the DC bus (DC-BUS), and the control unit is configured to output one of the fifth loop control signal and the sixth loop control signal to the DC-AC converter (13).

3. The energy storage and conversion device according to claim 2, characterized in that: The first DC-DC converter (11) is a unidirectional DC-DC converter; The control unit is configured to generate a first loop control signal (Upvout_1) based on a difference value between an output voltage (Upvfb) of the DC power supply (20) and a first threshold voltage (Upvref_1) and a maximum power loop controller (G1s), and to generate a second loop control signal (Upvout_2) based on a difference value between a bus voltage (Ubus) of the DC bus (DC-BUS) and a second threshold voltage (Upvref_2) and a first voltage regulation loop controller (G2s); The first threshold voltage (Upvref_1) is defined as the voltage corresponding to the first DC-DC converter operating at the maximum power point, and the second threshold voltage (Upvref_2) is the voltage at the stabilization point when the first DC-DC converter operates in the voltage stabilization mode; The control unit is configured to select one of the first loop control signal (Upvout_1) and the second loop control signal (Upvout_2) with a smaller signal duty cycle and output it to the first DC-DC converter (11).

4. The energy storage and current conversion device according to claim 2 or 3, characterized in that: The second DC-DC converter (12) is a unidirectional DC-DC converter or a bidirectional DC-DC converter; In response to the second DC-DC converter (12) operating in a charging mode, the control unit is configured to generate a third loop control signal (Ibatout_1) based on a difference value between a charging current (Ibatfb_1) of the second DC-DC converter and a first target current (Ibatref_1) and a first constant current loop controller (G3-1s), and to generate a fourth loop control signal (Ubatout_1) based on a difference value between a bus voltage (Ubus) of the DC bus (DC-BUS) and a third threshold voltage (Ubatref_1) and a second voltage regulation loop controller (G4-1s); The first target current (Ibatref_1) is defined as the constant current point current when the second DC-DC converter operates in the constant current charging mode, and the third threshold voltage (Ubatref_1) is the stabilization point voltage when the second DC-DC converter operates in the regulated voltage charging mode; and / or, In response to the second DC-DC converter (12) operating in a discharge mode, the control unit is configured to generate a third loop control signal (Ibatout_2) based on a difference between a discharge current (Ibatfb_2) of the second DC-DC converter and a second target current (Ibatref_2) and a second constant current loop controller (G3-2s), and to generate a fourth loop control signal (Ubatout_2) based on a difference between a bus voltage (Ubus) of the DC bus (DC-BUS) and a fourth threshold voltage (Ubatref_2) and a third voltage regulation loop controller (G4-2s); The second target current (Ibatref_2) is defined as the constant current point current when the second DC-DC converter operates in the constant current discharge mode, and the fourth threshold voltage (Ubatref_2) is the stabilization point voltage when the second DC-DC converter operates in the stabilization discharge mode; The control unit is further configured to select one of the third loop control signal and the fourth loop control signal with a smaller signal duty cycle and output it to the second DC-DC converter (12).

5. The energy storage and conversion device according to any one of claims 2 to 4, characterized in that: The DC-AC converter (13) comprises a unidirectional DC-AC converter or a bidirectional DC-AC converter; Wherein, the unidirectional DC-AC converter includes an inverter circuit, and the bidirectional DC-AC converter includes an inverter circuit and a power factor correction circuit; In response to the inverter circuit being in a working state, the control unit is configured to generate a fifth loop control signal (Igridout_1) based on a difference value between a power-drawn current (Igridfb_1) of the inverter circuit and a third target current (Igridref_1) and a third constant current loop controller (G5-1s), and to generate a sixth loop control signal (Ugridout_1) based on a difference value between a bus voltage (Ubus) of the DC bus (DC-BUS) and a fifth threshold voltage (Uinvref_1) and a fourth voltage regulation loop controller (G6-1s); The third target current (Igridref_1) is defined as the constant current point current when the inverter circuit operates in the constant current power supply mode, and the fifth threshold voltage (Uinvref_1) is the voltage stabilization point voltage when the inverter circuit operates in the voltage stabilization power supply mode; and / or, In response to the power factor correction circuit being in an operating state, the control unit is configured to generate a fifth loop control signal (Igridout_2) based on a difference value between a discharge current (Igridfb_2) of the power factor correction circuit and a fourth target current (Igridref_2) and a fourth constant current loop controller (G5-2s), and to generate a sixth loop control signal (Ugridout_2) based on a difference value between a bus voltage (Ubus) of the DC bus (DC-BUS) and a sixth threshold voltage (Upfcref_2) and a fifth voltage regulation loop controller (G6-2s); The fourth target current (Igridref_2) is defined as the constant current point current when the power factor correction circuit works in the constant current discharge mode, and the sixth threshold voltage (Upfcref_2) is the voltage stabilization point voltage when the power factor correction circuit works in the voltage stabilization discharge mode; The control unit is further configured to select one of the fifth loop control signal and the sixth loop control signal with a smaller signal duty cycle and output it to the inverter circuit or the power factor correction circuit.

6. The energy storage and conversion device according to claim 5, characterized in that: The magnitude relationship among the second threshold voltage (Upvref_2), the third threshold voltage (Ubatref_1), the fourth threshold voltage (Ubatref_2), the fifth threshold voltage (Uinvref_1), and the sixth threshold voltage (Upfcref_2) is: Upvref_2>Ubatref_2>Uinvref_1=Upfcref_2>Ubatref_1; or, Upvref_2>Ubatref_2>Ubatref_1>Uinvref_1=Upfcref_2.

7. A method for distributing electric energy, characterized in that: Applied to the energy storage and conversion device according to any one of claims 1 to 6, the electric energy distribution method comprises: Collecting the output voltage (Upvfb) of the DC power supply (20) and the bus voltage (Ubus) of the DC bus; Calculating a first voltage difference between a first threshold voltage (Upvref_1) of the DC power supply (20) and an output voltage (Upvfb) of the DC power supply, and a second voltage difference between a second threshold voltage (Upvref_2) and the bus voltage (Ubus); Calculating a first loop control signal (Upvout_1) corresponding to the first voltage difference based on a control algorithm of a maximum power loop controller (G1s); and calculating a second loop control signal (Upvout_2) corresponding to the second voltage difference based on a control algorithm of a first voltage regulation loop controller (G2s); The signal duty cycles of the first loop control signal (Upvout_1) and the second loop control signal (Upvout_2) are compared, and the one with the smaller signal duty cycle between the first loop control signal (Upvout_1) and the second loop control signal (Upvout_2) is output to a power conversion unit (10).

8. A method for distributing electric energy, characterized in that: Applied to the energy storage and conversion device according to any one of claims 2 to 6, the electric energy distribution method comprises: Collect the charging current (Ibatfb_1) or discharging current (Ibatfb_2) of the battery module and the bus voltage (Ubus) of the DC bus; Based on the charging current (Ibatfb_1) or the discharging current (Ibatfb_2) of the battery module, a current error value of the second DC-DC converter operating in a constant current mode is calculated; and, based on the bus voltage (Ubus), a voltage error value of the second DC-DC converter operating in a voltage regulation mode is calculated; Calculating a third loop control signal corresponding to the current error value based on a control algorithm corresponding to the second DC-DC converter operating in a constant current mode, and calculating a fourth loop control signal corresponding to the voltage error value based on a control algorithm corresponding to the second DC-DC converter operating in a voltage regulation mode; The signal duty ratios of the third loop control signal and the fourth loop control signal are compared, and the one with the smaller signal duty ratio between the third loop control signal and the fourth loop control signal is output to the power conversion unit.

9. The electric energy distribution method according to claim 8, characterized in that: The calculating of the current error value of the second DC-DC converter operating in the constant current mode based on the charging current (Ibatfb_1) or the discharging current (Ibatfb_2) of the battery module comprises: In response to the second DC-DC converter (12) operating in a charging mode, calculating a first current difference between a charging current (Ibatfb_1) of the battery module and a first target current (Ibatref_1) when the second DC-DC converter (12) operates in a constant current charging mode; and / or, In response to the second DC-DC converter (12) operating in a discharge mode, calculating a second current difference between a discharge current (Ibatfb_2) of the battery module and a second target current (Ibatref_2) when the second DC-DC converter (12) operates in a constant current discharge mode; The step of calculating the voltage error value of the second DC-DC converter in a voltage regulation mode based on the bus voltage (Ubus) comprises: In response to the second DC-DC converter (12) operating in a charging mode, calculating a third voltage difference between a third threshold voltage (Ubatref_1) and the bus voltage (Ubus); and / or, In response to the second DC-DC converter (12) operating in the discharge mode, a fourth voltage difference between a fourth threshold voltage (Ubatref_2) and the bus voltage (Ubus) is calculated.

10. The electric energy distribution method according to claim 8 or 9, characterized in that: The calculating, based on a control algorithm corresponding to the second DC-DC converter operating in a constant current mode, a third loop control signal corresponding to the current error value comprises: In response to the second DC-DC converter (12) operating in a charging mode, based on a control algorithm of a first constant current loop controller (G3-1s), a third loop control signal corresponding to the first current difference is calculated; and / or, In response to the second DC-DC converter (12) operating in a discharge mode, a third loop control signal corresponding to the second current difference is calculated based on a control algorithm of a second constant current loop controller (G3-2s); The calculating, based on a control algorithm corresponding to the second DC-DC converter operating in a voltage regulation mode, a fourth loop control signal corresponding to the voltage error value comprises: In response to the second DC-DC converter (12) operating in a charging mode, a fourth loop control signal corresponding to the third voltage difference is calculated based on a control algorithm of a second voltage regulation loop controller (G4-1s); and / or, In response to the second DC-DC converter (12) operating in the discharge mode, a fourth loop control signal corresponding to the fourth voltage difference is calculated based on a control algorithm of a third voltage regulation loop controller (G4-2s).

11. A method for distributing electric energy, characterized in that: Applied to the energy storage and conversion device according to any one of claims 2 to 6, the electric energy distribution method comprises: Collecting the power supply current (Igridfb_1) or the discharge current (Igridfb_2) of the AC power supply (40) and the bus voltage (Ubus) of the DC bus; Based on the power supply current (Igridfb_1) or the discharge current (Igridfb_2) of the AC power source (40), a current error value of the DC-AC converter operating in a constant current mode is calculated; and based on the bus voltage (Ubus), a voltage error value of the DC-AC converter operating in a voltage stabilization mode is calculated; Calculating a fifth loop control signal corresponding to the current error value based on a control algorithm corresponding to the DC-AC converter operating in a constant current mode, and calculating a sixth loop control signal corresponding to the voltage error value based on a control algorithm corresponding to the DC-AC converter operating in a voltage regulation mode; The signal duty ratios of the fifth loop control signal and the sixth loop control signal are compared, and the one with the smaller signal duty ratio between the fifth loop control signal and the sixth loop control signal is output to the power conversion unit.

12. The electric energy distribution method according to claim 11, characterized in that: The step of calculating the current error value of the DC-AC converter operating in a constant current mode based on the power supply current (Igridfb_1) or the discharge current (Igridfb_2) of the AC power source (40) comprises: In response to the inverter circuit being in an operating state, calculating a third current difference between a power supply current (Igridfb_1) of the AC power source (40) and a third target current (Igridref_1) when the inverter circuit operates in a constant current power supply mode; and / or, In response to the power factor correction circuit being in an operating state, calculating a fourth current difference between a discharge current (Igridfb_2) of the AC power source (40) and a fourth target current (Igridref_2) when the inverter circuit operates in a constant current discharge mode; The step of calculating the voltage error value of the DC-AC converter in a voltage regulation mode based on the bus voltage (Ubus) comprises: In response to the inverter circuit being in an operating state, calculating a fifth voltage difference between a fifth threshold voltage (Uinvref_1) and the bus voltage (Ubus); and / or, In response to the power factor correction circuit being in an operating state, a sixth voltage difference between a sixth threshold voltage (Upfcref_2) and the bus voltage (Ubus) is calculated.

13. The electric energy distribution method according to claim 11 or 12, characterized in that: The calculating of the fifth loop control signal corresponding to the current error value based on the control algorithm corresponding to the DC-AC converter operating in the constant current mode includes: In response to the inverter circuit being in an operating state, a fifth loop control signal corresponding to the third current difference is calculated based on a control algorithm of a third constant current loop controller (G5-1s); and / or, In response to the power factor correction circuit being in an operating state, based on a control algorithm of a fourth constant current loop controller (G5-2s), a fifth loop control signal corresponding to the fourth current difference is calculated; The calculating, based on a control algorithm corresponding to the DC-AC converter operating in a voltage stabilization mode, a sixth loop control signal corresponding to the voltage error value comprises: In response to the inverter circuit being in an operating state, based on a control algorithm of a fourth voltage regulation loop controller (G6-1s), a sixth loop control signal corresponding to the fifth voltage difference is calculated; and / or, In response to the power factor correction circuit being in an operating state, a sixth loop control signal corresponding to the sixth voltage difference is calculated based on a control algorithm of a fifth voltage regulation loop controller (G6-2s).

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