A new energy microgrid lithium battery storage, charging and replacement integrated system and control method thereof

Abstract

This invention discloses an integrated lithium battery charging, storage, and swapping system for a new energy microgrid and its control method. The system includes a new energy generator set, a mutual exclusion switch control circuit, a dispatch switch, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, an energy-type lithium battery module, a cascaded battery charging, storage, and swapping module, a power-type lithium battery module, and a DC / AC converter. The mutual exclusion switch control circuit connects the new energy generator set and the energy-type lithium battery module. The circuit controls the on / off state of the dispatch switch based on the power output of the new energy generator set and the output power of the energy-type lithium battery module, thereby coordinating the operation of different types of lithium battery modules. This invention achieves efficient coordinated operation of different types of lithium battery modules through switch mutual exclusion control, and also effectively improves the utilization rate of retired batteries and realizes on-site storage and consumption of new energy power generation.

Description

Technical Field

[0001] The present invention belongs to the technical field of microgrids, and in particular relates to a new energy microgrid lithium battery storage-charging-swap integrated system and a control method thereof. Background Art

[0002] At present, the application scenarios of microgrid power supply and energy storage formed by solar energy, wind power generation and lithium battery energy storage are gradually increasing. By building solar energy, wind power and other renewable energy storage power stations near local loads such as factories and industrial parks to supply power to local loads, and storing excess electricity in energy storage batteries, it is very important to ensure the normal power supply of the microgrid system when there is insufficient power generation resources at night or during peak hours. Using lithium battery energy storage systems to dispatch and control the power generated by microgrids can greatly improve the utilization efficiency of new energy power generation.

[0003] At the same time, the capacity of retired electric vehicle power batteries usually decays to 70%~80% of the initial capacity, and still has a high residual energy. If these batteries are not used properly, it will not only affect the environment, but also waste precious resources.

[0004] In order to maximize the use of retired batteries and improve the utilization rate of electricity generated by new energy, second-use battery modules or retired battery modules can be introduced into lithium battery energy storage systems. Retired batteries can store energy and replace electricity. While realizing the diversified recycling of retired batteries, the energy generated by new energy is stored in them, realizing the on-site conversion and energy storage of new energy power generation. However, the introduction of second-use batteries increases the complexity of the energy storage system. Effective controllers and control strategies are the guarantee of efficient and stable operation of energy storage systems. In addition, most traditional energy storage devices are energy-type batteries, which results in the inability to use electricity generated when the power generation is too high or too low, affecting the efficiency of power generation. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a new energy microgrid lithium battery storage, charging and replacement integrated system and its control method. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] The present invention provides a new energy microgrid lithium battery storage, charging and replacement integrated system, including a new energy generator set, a mutually exclusive switch control circuit, a first dispatching switch, a second dispatching switch, a third dispatching switch, a fourth dispatching switch, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, an energy type lithium battery module, a cascade battery charging, storage and replacement module, a power type lithium battery module and a DC / AC converter, wherein:

[0007] The new energy generator set, the first DC / DC converter, the energy-type lithium battery module, the second DC / DC converter, the cascade battery charging, storage and conversion module, the fourth dispatching switch, the third DC / DC converter, the power-type lithium battery module and the DC / AC converter are connected in sequence, the cascade battery charging, storage and conversion module can supply power to the DC power demand side and the diversified power exchange user demand side, and the power-type lithium battery module can supply power to the microgrid user side through the DC / AC conversion;

[0008] The first end of the first dispatching switch is connected to the new energy generator set, and the second end is connected to the power lithium battery module; the first end of the second dispatching switch is connected to the new energy generator set, and the second end is connected to the third DC / DC converter; the first end of the third dispatching switch is connected to the energy lithium battery module, and the second end is connected to the third DC / DC converter;

[0009] The mutually exclusive switch control circuit is connected to the output end of the new energy generator set and the output end of the energy-type lithium battery module. The mutually exclusive switch control circuit can control the on and off of the first scheduling switch, the second scheduling switch, the third scheduling switch and the fourth scheduling switch according to the power generation power of the new energy generator set and the output power of the energy-type lithium battery module to switch the coordinated operation of different types of lithium battery modules.

[0010] In one embodiment of the present invention, the first scheduling switch S1 and the second scheduling switch S2 are mutually exclusive controlled, and the third scheduling switch S3 and the fourth scheduling switch S4 are mutually exclusive controlled; the first scheduling switch S1 and the second scheduling switch S2 as a whole and the third scheduling switch S3 and the fourth scheduling switch S4 as a whole are mutually exclusive controlled.

[0011] In one embodiment of the present invention, the energy-type lithium battery module and the power-type lithium battery module have the same output voltage as the new energy generator set.

[0012] In one embodiment of the present invention, the mutually exclusive switch control circuit includes a circuit resistor R1, a circuit resistor R2, a circuit resistor R3, a circuit resistor R4, a circuit resistor R5, a circuit resistor R6, a circuit resistor R7, a circuit resistor R8, a circuit resistor R9, a grounding resistor R01, a grounding resistor R02, a grounding resistor R03, a grounding resistor R04, a grounding resistor R05, a photoelectric coupler OC1, a photoelectric coupler OC2, a photoelectric coupler OC3, a photoelectric coupler OC4, a transistor N1, a transistor N2, a transistor N3, a transistor N4, a transistor N5, a transistor N6, a relay K1, a relay K2, a relay K3 and a relay K4, wherein:

[0013] The base of the transistor N1 is connected to the output end of the new energy generator set, the emitter of the transistor N1 is connected to the ground end, and the circuit resistor R1 is connected between the power supply end and the collector of the transistor N1;

[0014] The base of the transistor N2 is connected to the output end of the energy-type lithium battery module, the collector of the transistor N2 is connected to the power supply end, and the grounding resistor R01 is connected between the emitter of the transistor N2 and the grounding end;

[0015] The circuit resistor R2 is connected between the collector of the transistor N1 and the first input terminal of the photocoupler OC1, and the grounding resistor R02 is connected between the collector of the transistor N1 and the grounding terminal; the circuit resistor R4 is connected between the collector of the transistor N1 and the first input terminal of the photocoupler OC3, and the grounding resistor R04 is connected between the collector of the transistor N1 and the grounding terminal;

[0016] The circuit resistor R3 is connected between the base of the transistor N1 and the first input terminal of the photocoupler OC2, and the grounding resistor R03 is connected between the base of the transistor N1 and the grounding terminal; the circuit resistor R5 is connected between the base of the transistor N1 and the first input terminal of the photocoupler OC4, and the grounding resistor R05 is connected between the base of the transistor N1 and the grounding terminal;

[0017] The second input end of the photoelectric coupler OC1 is connected to the first input end of the photoelectric coupler OC2, and the second input end of the photoelectric coupler OC2 is connected to the first input end of the photoelectric coupler OC1; the second input end of the photoelectric coupler OC3 is connected to the first input end of the photoelectric coupler OC4, and the second input end of the photoelectric coupler OC4 is connected to the first input end of the photoelectric coupler OC3;

[0018] The circuit resistor R6 is connected between the first output end of the photocoupler OC1 and the base of the transistor N3, the circuit resistor R7 is connected between the first output end of the photocoupler OC2 and the base of the transistor N4, the circuit resistor R8 is connected between the first output end of the photocoupler OC3 and the base of the transistor N5, and the circuit resistor R9 is connected between the first output end of the photocoupler OC4 and the base of the transistor N6;

[0019] The collector of the transistor N3, the collector of the transistor N4, the collector of the transistor N5 and the collector of the transistor N6 are all connected to the power supply end, the second output end of the photoelectric coupler OC1, the second output end of the photoelectric coupler OC2, the second output end of the photoelectric coupler OC3 and the second output end of the photoelectric coupler OC4 are all connected to the ground end, and the emitter of the transistor N2 is connected to the first output end of the photoelectric coupler OC1;

[0020] The relay K1 is connected between the emitter of the transistor N3 and the ground terminal, and is used to control the on and off of the first scheduling switch S1; the relay K2 is connected between the emitter of the transistor N4 and the ground terminal, and is used to control the on and off of the second scheduling switch S2; the relay K3 is connected between the emitter of the transistor N5 and the ground terminal, and is used to control the on and off of the third scheduling switch S3; the relay K4 is connected between the emitter of the transistor N6 and the ground terminal, and is used to control the on and off of the fourth scheduling switch S4.

[0021] In one embodiment of the present invention, the photoelectric coupler OC1, the photoelectric coupler OC2, the photoelectric coupler OC3 and the photoelectric coupler OC4 have the same structure, and each includes a light emitting diode and a phototransistor.

[0022] In one embodiment of the present invention, the battery charging, storage and replacement module includes a multi-voltage battery replacement unit and a plurality of lithium battery packs with different output voltages, the lithium battery packs are all retired lithium battery modules, the multi-voltage battery replacement unit is a detachable battery slot, and the lithium battery pack can be installed on the multi-voltage battery replacement unit in a detachable manner.

[0023] In one embodiment of the present invention, a portion of the plurality of lithium battery packs with different output voltages constitutes a lithium battery energy storage unit, which is only used for energy storage;

[0024] Another part of the multiple lithium battery packs with different output voltages constitutes a detachable lithium battery replacement unit, which can be replaced to charge the lithium battery pack that needs to be charged.

[0025] Another aspect of the present invention provides a control method for a new energy microgrid lithium battery storage, charging and replacement integrated system, which is performed using the new energy microgrid lithium battery storage, charging and replacement integrated system described in any one of the above embodiments, and the control method includes:

[0026] Step 1: Obtain the power generated by the new energy generator set;

[0027] Step 2: Determine whether the power generation of the new energy generator set is greater than a preset upper limit value. If so, the mutually exclusive switch control circuit controls the second scheduling switch S2 to be turned on, and the first scheduling switch S1, the third scheduling switch S3 and the fourth scheduling switch S4 are all turned off. A part of the power generated by the new energy generator set is charged to the energy type lithium battery module through the first DC / DC converter, and another part of the power generated by the new energy generator set is charged to the power type lithium battery module at maximum power through the third DC / DC converter; if not, execute step 3;

[0028] Step 3: Determine whether the power generation power of the new energy generator set is less than the upper limit value and greater than the preset lower limit value. If so, the mutually exclusive switch control circuit controls the first dispatching switch S1 to be turned on, and the second dispatching switch S2, the third dispatching switch S3 and the fourth dispatching switch S4 to be turned off. The power generated by the new energy generator set is directly supplied to the microgrid user side through the DC / AC converter. If not, execute step 4;

[0029] Step 4: Determine whether the power generation power of the new energy generator set is less than the lower limit value. If so, the mutually exclusive switch control circuit controls the third dispatching switch S3 to be turned on, and the first dispatching switch S1, the second dispatching switch S2 and the fourth dispatching switch S4 are turned off. The energy-type lithium battery charges the power-type lithium battery module through the third DC / DC converter, and the power-type lithium battery module supplies power to the microgrid user side through the DC / AC converter.

[0030] In one embodiment of the present invention, the step 2 further comprises:

[0031] When the generated power is greater than the upper limit value, if the energy-type lithium battery module has sufficient power, the second DC / DC converter can be used to provide charging for the cascade battery charging, storage and conversion module.

[0032] In one embodiment of the present invention, step 3 further includes:

[0033] When the power generation power of the new energy generator set is less than the upper limit value and greater than the lower limit value, if the voltage of the power type lithium battery module is higher than the limit voltage, the first DC / DC converter is turned on, and the energy type lithium battery module absorbs excess energy; when the energy type lithium battery module is sufficiently charged, the second DC / DC converter can be used to provide charging for the cascade battery charging, storage and replacement module.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. Different types of lithium battery modules are introduced into the integrated storage, charging and replacement system of lithium batteries in the new energy microgrid of the present invention. Among them, the energy type lithium battery module and the power type lithium battery module play their respective advantages of large-capacity energy storage and high-power charging and discharging, and the introduction of the cascade utilization lithium battery module (also called retired lithium battery module) can be used for energy storage and power supply, and can also be used for power replacement, realizing the diversified recycling of retired batteries. At the same time, the four dispatching switches are controlled respectively by the mutually exclusive switch control circuit, and work in conjunction with the three DC / DC converters, realizing the efficient coordination of different types of lithium battery modules in the integrated storage, charging and replacement system of lithium batteries in the new energy microgrid, while ensuring stable energy storage and power supply, and improving the utilization efficiency of new energy power generation.

[0036] 2. The present invention not only avoids mutual interference between different lithium battery energy storage modules through switch mutual exclusion control, but also realizes efficient coordinated operation of different types of lithium battery modules. In addition, the multi-voltage battery replacement unit can also play the role of energy storage module, effectively improving the utilization rate of retired batteries and realizing on-site storage and consumption of new energy power generation.

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of a new energy microgrid lithium battery storage, charging and replacement integrated system provided by an embodiment of the present invention;

[0039] Figure 2 is a circuit schematic diagram of a mutually exclusive switch control circuit provided by an embodiment of the present invention;

[0040] Figure 3 is a control flow chart of a mutually exclusive switch control circuit provided by an embodiment of the present invention;

[0041] Figure 4 It is a hysteresis control diagram provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following is a detailed description of a new energy microgrid lithium battery storage, charging and replacement integrated system and a control method thereof proposed in accordance with the present invention in combination with the accompanying drawings and specific implementation methods.

[0043] The above and other technical contents, features and effects of the present invention are clearly presented in the following detailed description of the specific implementation modes in conjunction with the accompanying drawings. Through the description of the specific implementation modes, the technical means and effects adopted by the present invention to achieve the predetermined purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and explanation purposes and are not used to limit the technical solutions of the present invention.

[0044] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the statement "including one..." do not exclude the existence of other identical elements in the article or device including the elements.

[0045] Embodiment 1

[0046] See also Figure 1 , Figure 1 This is a structural schematic diagram of a new energy microgrid lithium battery storage, charging and replacement integrated system provided by an embodiment of the present invention. The system includes a new energy generator set, a mutually exclusive switch control circuit, a first dispatching switch S1, a second dispatching switch S2, a third dispatching switch S3, a fourth dispatching switch S4, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, an energy type lithium battery module, a cascade battery charging, storage and replacement module, a power type lithium battery module and a DC / AC converter.

[0047] The new energy generator set, the first DC / DC converter, the energy-type lithium battery module, the second DC / DC converter, the cascade battery charging, storage and swapping module, the fourth dispatching switch S4, the third DC / DC converter, the power-type lithium battery module and the DC / AC converter are connected in sequence; the cascade battery charging, storage and swapping module can supply power to the DC power demand side and the diversified power swapping user demand side, and the power-type lithium battery module can supply power to the microgrid user side through DC / AC conversion; the first end of the first dispatching switch S1 is connected to the new energy generator set, and the second end is connected to the power-type lithium battery module; the first end of the second dispatching switch S2 is connected to the power type lithium battery module; The first end of the third dispatching switch S3 is connected to the energy type lithium battery module, and the second end is connected to the third DC / DC converter; the first end of the third dispatching switch S3 is connected to the energy type lithium battery module, and the second end is connected to the third DC / DC converter; the mutually exclusive switch control circuit is connected to the output end of the new energy generator set and the output end of the energy type lithium battery module, and the mutually exclusive switch control circuit can control the on and off of the first dispatching switch S1, the second dispatching switch S2, the third dispatching switch S3 and the fourth dispatching switch S4 according to the power generation power of the new energy generator set and the output power of the energy type lithium battery module, so as to switch the coordinated work of different types of lithium battery modules.

[0048] In this embodiment, the energy type lithium battery module and the power type lithium battery module have the same output voltage as the new energy generator set. Preferably, the new energy generator set in this embodiment is a 1500V new energy generator set, the energy type lithium battery module is a 1500V energy type lithium battery module, and the power type lithium battery module is a 1500V power type lithium battery module.

[0049] Furthermore, the first dispatching switch S1 and the second dispatching switch S2 are mutually exclusive switches, and the third dispatching switch S3 and the fourth dispatching switch S4 are mutually exclusive switches. The mutually exclusive switch control circuit can realize three mutually exclusive control functions of the four dispatching switches through only two control signals: the first dispatching switch S1 and the second dispatching switch S2 are mutually exclusive controlled, that is, if the first dispatching switch S1 is closed, the second dispatching switch S2 is disconnected, on the contrary, if the first dispatching switch S2 is closed, the second dispatching switch S1 is disconnected; the dispatching switches S1~S2 as a whole are mutually exclusive controlled with the dispatching switches S3~S4 as a whole, that is, if one of the dispatching switches S1 or S2 is closed, the dispatching switches S3 and S4 are both disconnected, on the contrary, if one of the dispatching switches S3 or S4 is closed, the dispatching switches S1 and S2 are both disconnected; the third dispatching switch S3 and the fourth dispatching switch S4 are mutually exclusive controlled. The above two control signals are respectively the power generation signals from the new energy generator set (such as Figure 2 The control signal 1 shown in FIG. 1 ) and the power signal from the energy type lithium battery module (such as Figure 2 For details, see Figure 2 , Figure 2 1 is a circuit schematic diagram of a mutually exclusive switch control circuit provided by an embodiment of the present invention. The mutually exclusive switch control circuit includes a circuit resistor R1, a circuit resistor R2, a circuit resistor R3, a circuit resistor R4, a circuit resistor R5, a circuit resistor R6, a circuit resistor R7, a circuit resistor R8, a circuit resistor R9, a grounding resistor R01, a grounding resistor R02, a grounding resistor R03, a grounding resistor R04, a grounding resistor R05, a photoelectric coupler OC1, a photoelectric coupler OC2, a photoelectric coupler OC3, a photoelectric coupler OC4, a transistor N1, a transistor N2, a transistor N3, a transistor N4, a transistor N5, a transistor N6, a relay K1, a relay K2, a relay K3 and a relay K4.

[0050] The base of transistor N1 is connected to the output end of the new energy generator set, and the new energy generator set is used to input a control signal 1 to the base of transistor N1. The emitter of transistor N1 is connected to the ground end, and the circuit resistor R1 is connected between the power supply end and the collector of transistor N1; the base of transistor N2 is connected to the output end of the energy-type lithium battery module, and the energy-type lithium battery module is used to input a control signal 2 to the base of transistor N2. The collector of transistor N2 is connected to the power supply end, and the grounding resistor R01 is connected between the emitter of transistor N2 and the ground end; the circuit resistor R2 is connected between the collector of transistor N1 and the first input of photoelectric coupler OC1. The circuit resistor R4 is connected between the collector of the transistor N1 and the first input terminal of the photocoupler OC3, and the grounding resistor R04 is connected between the collector of the transistor N1 and the grounding terminal; the circuit resistor R3 is connected between the base of the transistor N1 and the first input terminal of the photocoupler OC2, and the grounding resistor R03 is connected between the base of the transistor N1 and the grounding terminal; the circuit resistor R5 is connected between the base of the transistor N1 and the first input terminal of the photocoupler OC4, and the grounding resistor R05 is connected between the base of the transistor N1 and the grounding terminal.

[0051] The second input end of the photocoupler OC1 is connected to the first input end of the photocoupler OC2, and the second input end of the photocoupler OC2 is connected to the first input end of the photocoupler OC1; the second input end of the photocoupler OC3 is connected to the first input end of the photocoupler OC4, and the second input end of the photocoupler OC4 is connected to the first input end of the photocoupler OC3; the circuit resistor R6 is connected between the first output end of the photocoupler OC1 and the base of the transistor N3, the circuit resistor R7 is connected between the first output end of the photocoupler OC2 and the base of the transistor N4, the circuit resistor R8 is connected between the first output end of the photocoupler OC3 and the base of the transistor N5, and the circuit resistor R9 is connected between the first output end of the photocoupler OC4 and the base of the transistor N6.

[0052] The collector of transistor N3, the collector of transistor N4, the collector of transistor N5 and the collector of transistor N6 are all connected to the power supply end, the second output end of photoelectric coupler OC1, the second output end of photoelectric coupler OC2, the second output end of photoelectric coupler OC3 and the second output end of photoelectric coupler OC4 are all connected to the ground end, and the emitter of transistor N2 is connected to the first output end of photoelectric coupler OC1; relay K1 is connected between the emitter of transistor N3 and the ground end, and is used to control the on-off of the first scheduling switch S1; relay K2 is connected between the emitter of transistor N4 and the ground end, and is used to control the on-off of the second scheduling switch S2; relay K3 is connected between the emitter of transistor N5 and the ground end, and is used to control the on-off of the third scheduling switch S3; relay K4 is connected between the emitter of transistor N6 and the ground end, and is used to control the on-off of the fourth scheduling switch S4.

[0053] Photocoupler OC1, photocoupler OC2, photocoupler OC3 and photocoupler OC4 are photocouplers with the same structure, each including a light emitting diode and a phototransistor, wherein the positive electrode of the light emitting diode serves as the first input terminal of the current photocoupler, the negative electrode of the light emitting diode serves as the second input terminal of the current photocoupler, the collector of the phototransistor serves as the first output terminal of the current photocoupler, and the emitter of the phototransistor serves as the second output terminal of the current photocoupler.

[0054] Specifically, the mutually exclusive switch control circuit of this embodiment can realize three mutually exclusive control functions of four dispatching switches through only two control signals; the mutually exclusive switch control circuit is composed of a control signal circuit, two typical optocoupler isolation mutually exclusive switch circuits, a power supply mutually exclusive circuit and a relay, and controls strong electricity through weak electricity; the three mutually exclusive control functions are: mutual exclusive control of dispatching switches S1 and S2; mutual exclusive control of dispatching switches S1~S2 as a whole and dispatching switches S3~S4 as a whole; mutual exclusive control of dispatching switches S3 and S4.

[0055] The mutual exclusive control of S1 and S2, and the mutual exclusive control of S3 and S4 are realized by two typical optocoupler isolation mutual exclusive switch circuits, while the mutual exclusive control of S1~S2 and S3~S4 is realized by a power supply mutual exclusive circuit based on MOS switch; wherein: a control signal 1 controls two typical optocoupler isolation mutual exclusive switch circuits at the same time, and another control signal 2 controls the MOS switch power supply mutual exclusive circuit. This structure not only simplifies the circuit design, but also simplifies the control logic.

[0056] Furthermore, the battery charging, storage and replacement module for cascade utilization includes a multi-voltage battery replacement unit and a plurality of lithium battery packs with different voltages. The lithium battery packs are all retired lithium battery modules. The multi-voltage battery replacement unit is a detachable battery slot, and the lithium battery pack can be installed on the multi-voltage battery replacement unit in a detachable manner.

[0057] A portion of the multiple lithium battery packs with different output voltages constitutes a lithium battery energy storage unit, which is only used for energy storage; another portion of the multiple lithium battery packs with different output voltages constitutes a detachable lithium battery replacement unit, which can be replaced to charge the lithium battery module that needs to be charged.

[0058] Specifically, the second-use battery charging, storage and replacement module of the present embodiment includes a plurality of retired lithium battery modules (second-use lithium battery modules) with voltages of 100V / 200V / 300V / 500V, which can meet the 100V / 200V / 300V / 500V / 1500V DC power demand and the diversified power replacement demand. As lithium battery replacement units, these retired lithium battery modules can be recombined into 1500V lithium battery energy storage units, and then connected in parallel to increase the capacity of the second-use battery charging, storage and replacement module. In addition, a portion of the lithium battery packs with different voltages constitute a lithium battery energy storage unit, which is only used for energy storage. The second-use battery charging, storage and replacement module of the present embodiment includes a 1500V lithium battery energy storage unit composed of three 500V second-use lithium battery modules, which is specifically used for energy storage, and can ensure the stability of the power supply of the second-use battery charging, storage and replacement module.

[0059] The multi-voltage battery swap unit is equivalent to a replaceable battery slot. When battery swapping is required, the corresponding voltage battery swap module, such as a 200V lithium battery module to be charged, can be replaced with one of the fully charged 200V second-use lithium battery modules. After that, the second DC / DC converter will charge the newly replaced 200V lithium battery module to be charged separately. If the battery swap module is 300V, it can be replaced with a fully charged 300V second-use lithium battery module. It can also be replaced with a fully charged 200V and 100V second-use lithium battery module. The 300V battery swap module can be replaced for battery swapping. After that, the second DC / DC converter will charge the newly replaced 300V lithium battery module. When the battery swap user does not take away the battery swap module for a long time, it can also act as an energy storage module and form a 1500V lithium battery energy storage module with other second-use lithium battery modules, which can eventually be charged to the 1500V power lithium battery module through the third DC / DC converter.

[0060] Embodiment 2

[0061] Based on the first embodiment, this embodiment provides a control method for a new energy microgrid lithium battery storage, charging and replacement integrated system. This embodiment controls the dispatching switches S1~S4 respectively through the mutually exclusive switch control circuit according to the power generation power of the new energy generator set, and cooperates with three DC / DC converters (the first DC / DC converter, the second DC / DC converter, and the third DC / DC converter) to achieve efficient cooperation between different lithium battery modules. Figure 3 As shown, the control method specifically includes the following steps:

[0062] Step 1: Obtain the power generated by the new energy generator set.

[0063] Step 2: Determine whether the power generation power of the new energy generator set is greater than the preset upper limit value. If so, the mutually exclusive switch control circuit controls the second scheduling switch S2 to be turned on, and the first scheduling switch S1, the third scheduling switch S3 and the fourth scheduling switch S4 are all disconnected. A part of the power generated by the new energy generator set is charged to the energy type lithium battery module through the first DC / DC converter, and another part of the power generated by the new energy generator set is charged to the power type lithium battery module at maximum power through the third DC / DC converter; if not, execute step 3.

[0064] Specifically, when the power generation of the 1500V new energy generator set is greater than the upper limit value, the mutually exclusive switch control circuit controls the second dispatching switch S2 to be turned on. Due to the use of the mutually exclusive switch control circuit, the first dispatching switch S1 is turned off. At the same time, as long as one of the second dispatching switches S2 and S1 is turned on, S3 and S4 will be turned off. At this time, the first DC / DC converter and the third DC / DC converter are working, and part of the power generated by the 1500V new energy generator set is charged to the 1500V energy type lithium battery module through the first DC / DC converter, and the other part of the power generated by the 1500V new energy generator set is charged to the 1500V power type lithium battery module at maximum power through the third DC / DC converter, avoiding the impact of super-high power on the energy type lithium battery module and the power type lithium battery module. In addition, if the energy type lithium battery module has sufficient power, it can be charged for the cascade utilization battery charging and storage module through the second DC / DC converter. Finally, on the user side of the microgrid, the 1500V power type lithium battery module provides electrical energy through the DC / AC converter.

[0065] Step 3: Determine whether the power generation power of the new energy generator set is less than the upper limit value and greater than the preset lower limit value. If so, the mutually exclusive switch control circuit controls the first dispatching switch S1 to be turned on, and the second dispatching switch S2, the third dispatching switch S3 and the fourth dispatching switch S4 to be turned off. The power generated by the new energy generator set is directly supplied to the microgrid user side through the DC / AC converter. If not, execute step 4.

[0066] In this embodiment, when the power generation of the 1500V new energy generator set is less than the upper limit and greater than the lower limit, the mutually exclusive switch control circuit controls the first dispatching switch S1 to be turned on. Due to the use of the mutually exclusive switch control circuit, the second dispatching switch S2 is turned off. At the same time, as long as one of the second dispatching switches S2 and S1 is turned on, S3 and S4 will be turned off. At this time, the power generated by the 1500V new energy generator set is directly supplied to the user side of the microgrid through the DC / AC converter. Further, if the voltage of the 1500V power type lithium battery module is higher than the limited voltage, the first DC / DC converter is turned on, and the excess energy is absorbed by the 1500V energy type lithium battery module. When the energy type lithium battery module is fully charged, the second DC / DC converter can be used to provide charging for the cascade battery charging and storage module. Correspondingly, the third DC / DC converter does not work.

[0067] Step 4: Determine whether the power generation power of the new energy generator set is less than the lower limit value. If so, the mutually exclusive switch control circuit controls the third dispatching switch S3 to be turned on, and the first dispatching switch S1, the second dispatching switch S2 and the fourth dispatching switch S4 are turned off. The energy type lithium battery charges the power type lithium battery module through the third DC / DC converter, and the power type lithium battery module supplies power to the microgrid user side through the DC / AC converter.

[0068] Specifically, when the power generation power of the 1500V new energy generator set is less than the lower limit value, at this time, the power generation power of the new energy generator set is insufficient, and the power supply of the first optocoupler isolation mutually exclusive switch circuit in the mutually exclusive switch control circuit is disconnected, so that the scheduling switches S1 and S2 are closed and cut off. Correspondingly, the power supply of the second optocoupler isolation mutually exclusive switch circuit will be turned on, and the 1500V new energy generator set charges the 1500V energy type lithium battery module through the first DC / DC converter. The mutually exclusive switch control circuit controls the third scheduling switch S3 to turn on, and the corresponding fourth scheduling switch S4 is closed. The 1500V energy type lithium battery module charges the 1500V power type lithium battery module through the third DC / DC converter. On the user side of the microgrid, the 1500V power type lithium battery module is powered by the DC / AC converter; at this time, due to the small power generation power, the voltage of the 1500V energy type lithium battery module will gradually decrease, and the second DC / DC converter will be closed, and no longer provide charging energy for the cascade battery charging, storage and replacement module. Furthermore, if the energy-type lithium battery module is low on power, the mutually exclusive switch control circuit controls the third scheduling switch S3 to be closed and cut off, and the fourth scheduling switch S4 to be turned on, and the cascade battery charging, storage and swapping module charges the 1500V power-type lithium battery module through the third DC / DC converter. On the user side of the microgrid, the 1500V power-type lithium battery module still supplies power to the user side of the microgrid through the DC / AC converter; at this time, the second DC / DC converter is turned off, and the cascade battery charging, storage and swapping module is not allowed to swap power and supply power to the outside.

[0069] See also Figure 4 , Figure 4 It is a hysteresis control diagram provided by an embodiment of the present invention. The upper limit and lower limit of this embodiment can be designed as a 5% hysteresis interval to avoid the scheduling switch and the DC-DC converter from frequently switching the working mode in the area near the upper limit and lower limit. In other words, the normal power generation module power generation voltage is not stable. For example, when a 1500V generator set is working normally, the voltage will fluctuate between about 1490V and 1510V. If the hysteresis interval is not set, the working mode will switch frequently. After setting a hysteresis interval, for example, starting when it is higher than 1510V and shutting down when it is lower than 1490V, the frequent switching of the working mode can be avoided, and the stability of the system can be improved.

[0070] Different types of lithium battery modules are introduced into the integrated storage, charging and replacement system of lithium batteries in the new energy microgrid of the present invention, among which the energy type lithium battery module and the power type lithium battery module play their respective advantages of large-capacity energy storage and high-power charging and discharging, and introduce the cascade utilization lithium battery module (also called retired lithium battery module), which can be used for energy storage and power supply, and can also be used for power replacement, realizing the diversified recycling of retired batteries. At the same time, the four dispatching switches S1~S4 are controlled respectively by the mutually exclusive switch control circuit, and work in conjunction with the three DC / DC converters, so as to realize the efficient coordination of different types of lithium battery modules in the integrated storage, charging and replacement system of lithium batteries in the new energy microgrid, and improve the utilization efficiency of new energy power generation while ensuring stable energy storage and power supply. The present invention not only avoids the mutual interference of different types of lithium battery modules through the switch mutual exclusion control, but also realizes the efficient coordination of different types of lithium battery modules. In addition, the multi-voltage power replacement unit can also play the role of energy storage module, effectively improving the utilization rate of retired batteries and realizing the on-site storage and consumption of new energy power generation.

[0071] In the several embodiments provided by the present invention, it should be understood that the apparatus and method disclosed by the present invention can be implemented in other ways. For example, the apparatus embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0072] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0073] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A new energy microgrid lithium battery storage, charging and replacement integrated system, characterized in that: It includes a new energy generator set, a mutually exclusive switch control circuit, a first dispatching switch S1, a second dispatching switch S2, a third dispatching switch S3, a fourth dispatching switch S4, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, an energy-type lithium battery module, a cascade battery charging and storage module, a power-type lithium battery module and a DC / AC converter, wherein: The new energy generator set, the first DC / DC converter, the energy-type lithium battery module, the second DC / DC converter, the cascade battery charging, storage and replacement module, the fourth dispatching switch S4, the third DC / DC converter, the power-type lithium battery module and the DC / AC converter are connected in sequence, the cascade battery charging, storage and replacement module can supply power to the DC power demand side and the diversified power replacement user demand side, and the power-type lithium battery module can supply power to the microgrid user side through the DC / AC converter; The first end of the first dispatching switch S1 is connected to the output end of the new energy generator set, and the second end is connected to the output end of the power lithium battery module; the first end of the second dispatching switch S2 is connected to the output end of the new energy generator set, and the second end is connected to the input end of the third DC / DC converter; the first end of the third dispatching switch S3 is connected to the output end of the energy lithium battery module, and the second end is connected to the input end of the third DC / DC converter; The mutually exclusive switch control circuit is connected to the output end of the new energy generator set and the output end of the energy-type lithium battery module. The mutually exclusive switch control circuit can control the on and off of the first dispatching switch, the second dispatching switch, the third dispatching switch and the fourth dispatching switch according to the power generation power of the new energy generator set and the output power of the energy-type lithium battery module, so as to switch the coordinated work of different types of lithium battery modules; The first scheduling switch S1 and the second scheduling switch S2 are mutually exclusive controlled, and the third scheduling switch S3 and the fourth scheduling switch S4 are mutually exclusive controlled; the first scheduling switch S1 and the second scheduling switch S2 as a whole and the third scheduling switch S3 and the fourth scheduling switch S4 as a whole are mutually exclusive controlled.

2. The new energy microgrid lithium battery storage, charging and replacement integrated system according to claim 1 is characterized in that: The energy-type lithium battery module and the power-type lithium battery module have the same output voltage as the new energy generator set.

3. The new energy microgrid lithium battery storage, charging and replacement integrated system according to claim 1 is characterized in that: The cascade utilization battery charging, storage and replacement module includes a multi-voltage battery replacement unit and a plurality of lithium battery packs with different output voltages. The lithium battery packs are all retired lithium battery modules. The multi-voltage battery replacement unit is a detachable battery slot, and the lithium battery pack can be installed on the multi-voltage battery replacement unit in a detachable manner.

4. The new energy microgrid lithium battery storage, charging and replacement integrated system according to claim 3 is characterized in that: A portion of the plurality of lithium battery packs with different output voltages constitutes a lithium battery energy storage unit, which is only used for energy storage; Another part of the multiple lithium battery packs with different output voltages constitutes a detachable lithium battery replacement unit, which can be replaced to charge the lithium battery pack that needs to be charged.

5. A control method for a new energy microgrid lithium battery storage, charging and replacement integrated system, characterized in that: The control method is performed by using the new energy microgrid lithium battery storage, charging and replacement integrated system according to any one of claims 1 to 4, and includes: Step 1: Obtain the power generated by the new energy generator set; Step 2: Determine whether the power generation of the new energy generator set is greater than a preset upper limit value. If so, the mutually exclusive switch control circuit controls the second scheduling switch S2 to be turned on, and the first scheduling switch S1, the third scheduling switch S3 and the fourth scheduling switch S4 are all turned off. A part of the power generated by the new energy generator set is charged to the energy type lithium battery module through the first DC / DC converter, and another part of the power generated by the new energy generator set is charged to the power type lithium battery module at maximum power through the third DC / DC converter; if not, execute step 3; Step 3: Determine whether the power generation power of the new energy generator set is less than a preset upper limit value and greater than a preset lower limit value. If so, the mutually exclusive switch control circuit controls the first dispatching switch S1 to be turned on, and the second dispatching switch S2, the third dispatching switch S3 and the fourth dispatching switch S4 to be turned off. The power generated by the new energy generator set is directly supplied to the microgrid user side through the DC / AC converter. If not, execute step 4; Step 4: Determine whether the power generation power of the new energy generator set is less than the preset lower limit value. If so, the mutually exclusive switch control circuit controls the third scheduling switch S3 to be turned on, and the first scheduling switch S1, the second scheduling switch S2 and the fourth scheduling switch S4 are turned off. The energy type lithium battery module charges the power type lithium battery module through the third DC / DC converter, and the power type lithium battery module supplies power to the microgrid user side through the DC / AC converter.

6. The control method of the new energy microgrid lithium battery storage, charging and replacement integrated system according to claim 5 is characterized in that: The step 2 also includes: When the generated power is greater than a preset upper limit value, if the energy-type lithium battery module has sufficient power, the second DC / DC converter can be used to provide charging for the cascade battery charging, storage and conversion module.

7. The control method of the new energy microgrid lithium battery storage, charging and replacement integrated system according to claim 5 is characterized in that: The step 3 also includes: When the power generation power of the new energy generator set is less than the preset upper limit value and greater than the preset lower limit value, if the voltage of the power type lithium battery module is higher than the limit voltage, the first DC / DC converter is turned on, and the energy type lithium battery module absorbs excess energy; when the energy type lithium battery module is sufficiently charged, the second DC / DC converter can be used to provide charging for the cascade battery charging, storage and replacement module.

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