Power protection system based on parallel connection of multiple mobile energy storage power sources and parallel capacity expansion method

Abstract

The present application discloses a power protection system based on multiple mobile energy storage power supplies in parallel and a parallel capacity expansion method. The power protection system includes a grid-connected switch unit, a mobile energy storage power supply unit and a control unit, wherein the mobile energy storage power supply unit has a parallel cascade auxiliary interface; the parallel switch unit is composed of a fast switch or a static switch, a switch branch voltage and current detection unit and a branch protection; the mobile energy storage power supply is composed of an energy storage battery management system, an energy storage converter and a switch, and each mobile energy storage power supply is provided with two parallel cascade auxiliary interfaces, and the circuit power of the cascade interface is the number of parallel connections * the rated power capacity of a single mobile energy storage unit; the control unit is used to monitor, control and protect the power protection system based on multiple mobile energy storage power supplies in parallel.

Description

Technical Field

[0001] The present application relates to the field of mobile energy storage technology, and in particular to a power protection system based on parallel connection of multiple mobile energy storage power supplies and a parallel capacity expansion method. Background Art

[0002] With the increasing dependence of modern society on electric energy, the rapid growth of electricity demand, and the increasingly high requirements for power supply quality, sudden power outages will inevitably cause damage to people's normal life order and the normal operation of society, especially for important loads and major political activities. Once the power supply is interrupted, it will cause major political impact or economic losses. As the main force of power grid emergency power supply equipment, mobile emergency power supply vehicles have many advantages such as flexibility, mature technology, and rapid start-up. They play an increasingly significant role in civil fields such as political power supply, forestry system, electricity, communications, large-scale activities, exhibition centers, disaster relief, communities, field exploration, engineering operations, construction, film and television shooting sites, etc., as well as small and medium-sized power consumption places such as fighting major natural disasters and temporary power supply in power-scarce areas.

[0003] At present, the emergency power supply systems widely used include emergency power supply systems with diesel generators and lead-acid batteries as backup, and mobile energy storage systems that combine UPS and lithium iron phosphate battery energy storage technology. However, the disadvantages of diesel generators are that they cannot run at no load for a long time, are noisy, cause exhaust pollution, have large fluctuations in supply voltage and frequency, and are inefficient; the disadvantages of lead-acid batteries are heavy metal pollution, low specific energy, short life, and bulkiness; UPS power protection is difficult to connect in series and parallel, and it is difficult to achieve temporary capacity expansion and other needs. Compared with different power loads, a single mobile energy storage unit cannot meet all power supply needs.

[0004] The emergency power supply systems currently widely used in the above-mentioned prior art include emergency power supply systems with diesel generators and lead-acid batteries as backup, and mobile energy storage systems that combine UPS and lithium iron phosphate battery energy storage technology. However, the disadvantages of diesel generators are that they cannot run at no load for a long time, are noisy, cause exhaust pollution, have large fluctuations in supply voltage and frequency, and are inefficient; the disadvantages of lead-acid batteries are heavy metal pollution, low specific energy, short life, and bulkiness; UPS power protection is difficult to connect in series and parallel, and it is difficult to achieve temporary capacity expansion and other requirements. With respect to different power loads, a single mobile energy storage unit cannot meet the technical problem of all power supply needs, and no effective solution has been proposed so far. Summary of the invention

[0005] The embodiments of the present disclosure provide a power protection system based on multiple mobile energy storage power supplies in parallel and a parallel capacity expansion method, so as to at least solve the existing problems in the prior art that the currently widely used emergency power supply systems include emergency power supply systems with diesel generators and lead-acid batteries as backup, and mobile energy storage systems combining UPS and lithium iron phosphate battery energy storage technology. The disadvantages of diesel generators are that they cannot run at no load for a long time, they are noisy, they pollute exhaust gas, they have large fluctuations in supply voltage and frequency, and they are inefficient; the disadvantages of lead-acid batteries are heavy metal pollution, low specific energy, short life, and bulkiness; UPS power protection is difficult to connect in series and parallel, and it is difficult to achieve temporary capacity expansion and other requirements. With respect to different power loads, a single mobile energy storage unit cannot meet all power supply needs.

[0006] According to one aspect of an embodiment of the present disclosure, there is provided a power protection system based on multiple mobile energy storage power supplies in parallel, the power protection system comprising a grid-connected switch unit, a mobile energy storage power supply unit and a control unit, the mobile energy storage power supply unit having a parallel cascade auxiliary interface; the parallel switch unit is composed of a fast switch or a static switch, a switch branch voltage and current detection unit and a branch protection; the mobile energy storage power supply is composed of an energy storage battery management system, an energy storage inverter and a switch, each mobile energy storage power supply is provided with two parallel cascade auxiliary interfaces, and the circuit power of the cascade interface is the parallel number*the rated power capacity of a single mobile energy storage unit; the control unit is used for monitoring, controlling and protecting the power protection system based on multiple mobile energy storage power supplies in parallel.

[0007] According to another aspect of an embodiment of the present disclosure, a parallel capacity increase method for a power protection system is also provided, including: comparing the load power with the power of a single mobile energy storage power supply, determining two different parallel capacity increase methods, the first parallel capacity increase method is that the load power is greater than the power of a single mobile energy storage power supply, and the second parallel capacity increase method is that the load power is less than the power of a single mobile power supply; when the power protection system adopts the first parallel capacity increase method, multiple mobile energy storage power supplies are connected in parallel in a cascade manner; when the power protection system adopts the second parallel capacity increase method, multiple mobile energy storage power supplies are connected in parallel to the power grid bus.

[0008] According to another aspect of the embodiment of the present disclosure, a multi-mode operation strategy method for a power protection system is also provided, including: comparing the load power with the power of a single mobile energy storage power supply, determining two different parallel capacity increase methods, the first parallel capacity increase method is that the load power is greater than the power of a single mobile energy storage power supply, and the second parallel capacity increase method is that the load power is less than the power of a single mobile power supply; determining multiple operation modes of a power protection system based on parallel connection of multiple mobile energy storage power supplies, the multiple operation modes including a grid-connected power protection mode, an off-grid power supply mode, and a grid-connected / off-grid mode; under multiple operation modes, determining the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method.

[0009] In the present invention, according to a power protection system based on parallel connection of multiple mobile energy storage power sources, it can be flexibly connected in parallel to adapt to the power supply and power protection requirements of different loads in multiple scenarios. According to a parallel capacity expansion method of a power protection system, different parallel modes can be selected according to the power of the load to meet the capacity expansion requirements in terms of power and energy. According to a multi-mode operation strategy method of a power protection system, a variety of advanced power electronics and microgrid control technologies are integrated, and the coordinated operation is optimized in different modes to ensure high-quality power supply quality and achieve "zero flicker" on-grid and off-grid switching. Based on the energy storage converter (PCS) technology, the present invention proposes a multi-mobile energy storage parallel technology to realize the functions of multi-machine parallel connection and uninterrupted power protection, meet the different needs of various scenarios such as emergency power supply, backup power supply, temporary power supply, temporary capacity expansion of substations, mobile power banks, etc., and is bound to have broad application prospects in the field of mobile power supply.

[0010] This solves the existing problems in the existing technology. The emergency power supply systems widely used currently include emergency power supply systems with diesel generators and lead-acid batteries as backup, and mobile energy storage systems that combine UPS and lithium iron phosphate battery energy storage technology. However, the disadvantages of diesel generators are that they cannot run at no load for a long time, are noisy, cause exhaust pollution, have large fluctuations in supply voltage and frequency, and are inefficient; the disadvantages of lead-acid batteries are heavy metal pollution, low specific energy, short life, and bulkiness; UPS power protection is difficult to connect in series and parallel, and it is difficult to achieve temporary capacity expansion and other requirements. Compared with different power loads, a single mobile energy storage unit cannot meet all power supply needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present application. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure. In the drawings:

[0012] Figure 1 It is a schematic diagram of the architecture of a secondary control unit of a power protection system based on multiple mobile energy storage power supplies in parallel according to an embodiment of the present disclosure;

[0013] Figure 2 is a schematic diagram of an energy storage system according to an embodiment of the present disclosure, based on a power protection system of multiple mobile energy storage power sources connected in parallel;

[0014] Figure 3 is a flow chart of a parallel capacity increasing method of a power protection system according to the second aspect of an embodiment of the present disclosure;

[0015] Figure 4 is a schematic diagram of a parallel capacity increasing method 1 according to an embodiment of the present disclosure;

[0016] Figure 5is a schematic diagram of an equivalent circuit of a parallel capacity increasing method 1 according to an embodiment of the present disclosure;

[0017] Figure 6 is a schematic diagram of a parallel capacity increasing method 2 according to an embodiment of the present disclosure;

[0018] Figure 7 is a schematic diagram of an equivalent circuit of a parallel capacity increasing method 2 according to an embodiment of the present disclosure;

[0019] Figure 8 is a flow chart of a multi-mode operation strategy method of a power protection system according to the third aspect of an embodiment of the present disclosure;

[0020] Fig. 9 is a schematic diagram of a power conservation mode of a parallel capacity increasing method 1 according to an embodiment of the present disclosure;

[0021] Fig.10 is a schematic diagram of a power conservation mode of a parallel capacity increasing method 2 according to an embodiment of the present disclosure;

[0022] Fig.11 It is a schematic diagram of an off-grid power supply mode according to the parallel capacity increasing method 1 described in an embodiment of the present disclosure;

[0023] Fig.12 is a schematic diagram of an off-grid power supply mode according to the parallel capacity increasing method 2 described in an embodiment of the present disclosure;

[0024] Fig.13 is a schematic diagram of an on-grid / off-grid mode of a parallel capacity increasing method 1 according to an embodiment of the present disclosure;

[0025] Fig.14 is a schematic diagram of an on-grid / off-grid mode of a parallel capacity increasing method 2 according to an embodiment of the present disclosure; DETAILED DESCRIPTION

[0026] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0027] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0028] According to a first aspect of the present embodiment, a power protection system based on multiple mobile energy storage power supplies in parallel is provided, the power protection system comprising a grid-connected switch unit, a mobile energy storage power supply unit and a control unit, the mobile energy storage power supply unit having a parallel cascade auxiliary interface; the parallel switch unit is composed of a fast switch or a static switch, a switch branch voltage and current detection unit and a branch protection; the mobile energy storage power supply is composed of an energy storage battery management system, an energy storage converter and a switch, each mobile energy storage power supply is provided with two parallel cascade auxiliary interfaces, and the circuit power of the cascade interface is the parallel number*the rated power capacity of a single mobile energy storage unit; the control unit is used to monitor, control and protect the power protection system based on multiple mobile energy storage power supplies in parallel.

[0029] Specifically, refer to Figure 1 As shown, the power protection system grid-connected switch unit, mobile energy storage power supply unit with parallel cascade auxiliary interface, and control unit. The grid-connected switch unit is composed of a fast switch or a static switch, switch branch voltage and current detection, and branch protection. The mobile energy storage power supply refers to the energy storage battery and battery management system, energy storage converter (PCS), and switches (K1, K2, K3). Each mobile energy storage is designed with two parallel cascade auxiliary interfaces (③, ④), refer to Figure 2 As shown, the circuit power of the cascade interface is the parallel number (set as n, n>1)*the rated capacity of a single mobile energy storage power supply. The control unit is used for monitoring, controlling and protecting a power protection system based on parallel connection of multiple mobile energy storage power supplies.

[0030] According to a second aspect of this embodiment, a parallel capacity increasing method for a power protection system is provided, referring to Figure 3 As shown, the method includes:

[0031] S302: Compare the load power with the power of a single mobile energy storage power source, and determine two different parallel capacity increase methods, wherein the first parallel capacity increase method is that the load power is greater than the power of a single mobile energy storage power source, and the second parallel capacity increase method is that the load power is less than the power of a single mobile power source;

[0032] S304: When the power protection system adopts the first parallel capacity expansion method, multiple mobile energy storage power sources are connected in parallel in a cascade manner;

[0033] S306: When the power protection system adopts the second parallel capacity expansion method, multiple mobile energy storage power sources are connected in parallel to the grid bus.

[0034] Specifically, the parallel capacity expansion method of this embodiment includes two kinds, namely: parallel capacity expansion method 1: the load power (is it the load power of the power protection system) is greater than the power of a single mobile energy storage unit (P 负荷 >P 移动储能) when the load power is less than the power of a single mobile energy storage unit (P 负荷 <P 移动储能 ) when parallel capacity expansion is performed. Each solution can achieve capacity expansion in terms of power and energy.

[0035] Parallel capacity expansion method 1: N mobile energy storage power supplies are connected in parallel in cascade mode. Port ③ of mobile energy storage power supply 1 is connected to the grid; Port ④ of mobile energy storage power supply n is connected to port ③ of mobile energy storage power supply n+1 in sequence (2≤n+1≤N), and port ④ of mobile energy storage power supply N is connected to the load. Figure 4 As shown, its equivalent circuit is shown in Figure 5.

[0036] Parallel capacity increase method 2: Port ② of mobile energy storage power supply 1 is connected to load 1; port ② of mobile energy storage power supply 2 is connected to load 2; ...; port ② of mobile energy storage power supply n is connected to load n (1≤n≤N). Mobile energy storage power supply 1, mobile energy storage power supply 2, ..., mobile energy storage power supply N are connected in parallel to the grid bus, such as Figure 6 As mentioned above, its equivalent circuit is as follows Figure 7 shown.

[0037] Optionally, when the power protection system adopts the first parallel capacity expansion method, multiple mobile energy storage power supplies are connected in parallel in a cascade manner, including: connecting port ③ of mobile energy storage power supply n to the power grid, connecting port ④ of mobile energy storage power supply n to port ③ of mobile energy storage power supply n+1 in sequence (2≤n+1≤N), and connecting port ④ of mobile energy storage power supply N to the load.

[0038] Optionally, when the load power is less than the power of a single mobile power supply, multiple mobile energy storage power supplies are connected in parallel to the grid bus, including: connecting port ② of mobile energy storage power supply 1 to load 1, connecting port ② of mobile energy storage power supply 2 to load 2, and connecting port ② of mobile energy storage power supply n to load n in sequence (1≤n≤N).

[0039] According to a third aspect of this embodiment, a multi-mode operation strategy method for a power protection system is provided, referring to Figure 8 As shown, the method includes:

[0040] S802: Compare the load power with the power of a single mobile energy storage power source, and determine two different parallel capacity increase methods, wherein the first parallel capacity increase method is that the load power is greater than the power of a single mobile energy storage power source, and the second parallel capacity increase method is that the load power is less than the power of a single mobile power source;

[0041] S804: Determine multiple operating modes of a power protection system based on multiple mobile energy storage power sources in parallel, wherein the multiple operating modes include a grid-connected power protection mode, an off-grid power supply mode, and a grid-connected / off-grid mode;

[0042] S806: Under multiple operation modes, determine the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method.

[0043] Specifically, the multi-mode operation strategy method of the power protection system includes three operation modes: grid-connected power protection mode, off-grid power supply mode, and charge-discharge mode. In the parallel power protection mode, the two parallel capacity expansion methods adopt different operation strategies. Parallel capacity expansion method 1: The switch devices K1 and K2 in the mobile energy storage power supply n (1≤n≤N) are closed, K3 is disconnected, and the grid-connected switch unit is closed to achieve parallel expansion of N mobile energy storage power supplies to meet the power protection needs of large power loads, such as Fig. 9 Parallel expansion method 2: The switch devices K1, K2, and K3 in the mobile energy storage power supply n (1≤n≤N) are closed to achieve parallel expansion of N mobile energy storage power supplies, which are respectively used to maintain power for N small power loads, such as Fig.10 As shown. Off-grid power supply mode: In the off-grid power supply mode, the two parallel capacity expansion methods adopt different operation strategies. Parallel capacity expansion method 1: The switch devices K1 and K2 in the mobile energy storage power supply n (1≤n≤N) are closed, K3 is disconnected, and the grid-connected switch unit is suspended to achieve parallel capacity expansion of N mobile energy storage power supplies to meet the power protection requirements of high-power loads, such as Fig.11 Parallel capacity expansion method 2: The switch device K1 in the mobile energy storage power supply n (1≤n≤N) is disconnected, K2 and K3 are closed, and N mobile energy storage power supplies are connected to N loads respectively, and then connected to the grid in parallel to provide power for N small power loads, such as Fig.12 As shown. On-grid / off-grid mode: In the on-grid / off-grid mode, the two parallel capacity expansion methods adopt different operation strategies. Parallel capacity expansion method 1: When the grid is switched to off-grid, the switch devices K1 and K2 in the mobile energy storage power supply n (1≤n≤N) are closed, and K3 is disconnected. The grid-connected switch unit is disconnected from the closed state, realizing the transformation of the grid-connected mode of N mobile energy storage power supplies to the off-grid mode. Fig.13 Parallel capacity expansion method 2: The switch device K1 in the mobile energy storage power supply n (1≤n≤N) is opened from the closed state, K2 is closed, and K3 is closed, so that N mobile energy storage power supplies are transformed from the grid-connected mode to the off-grid mode, as shown in FIG. Fig.14 shown.

[0044] Optionally, under multiple operating modes, operating strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined, including: in the grid-connected power supply mode, the operating strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined; in the off-grid power supply mode, the operating strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined; in the on / off-grid mode, the operating strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined.

[0045] Optionally, in the grid-connected power protection mode, the operation strategies of the first parallel capacity expansion method and the second parallel capacity expansion method are determined, including: when the power protection system is the first parallel capacity expansion method, the switch devices K1 and K2 in the mobile energy storage power supply n (1≤n≤N) are closed, K3 is disconnected, and the grid-connected switch unit is closed to achieve parallel capacity expansion of N mobile energy storage power supplies to meet the power protection needs of high-power loads; when the power protection system is the second parallel capacity expansion method, the switch devices K1, K2, and K3 in the mobile energy storage power supply n (1≤n≤N) are closed to achieve parallel capacity expansion of N mobile energy storage power supplies, respectively protecting the power of N small-power loads.

[0046] Optionally, in the off-grid power supply mode, the operation strategies of the first parallel capacity expansion method and the second parallel capacity expansion method are determined, including: when the power protection system adopts the first parallel capacity expansion method, the switch devices K1 and K2 in the mobile energy storage power supply n (1≤n≤N) are closed, K3 is disconnected, and the grid-connected switch unit is suspended to realize parallel capacity expansion of N mobile energy storage power supplies to meet the power protection demand of high-power loads; when the power protection system adopts the second parallel capacity expansion method, the switch device K1 in the mobile energy storage power supply n (1≤n≤N) is disconnected, K2 and K3 are closed, and the N mobile energy storage power supplies are respectively connected to N loads and connected to the power grid in parallel to protect the power of N small-power loads.

[0047] Optionally, in the on-grid / off-grid mode, the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined, including: when the power protection system is the second parallel capacity increase method, the switch devices K1 and K2 in the mobile energy storage power supply n (1≤n≤N) are closed, K3 is disconnected, and the grid-connected switch unit is disconnected from a closed state, so as to realize the transformation of the on-grid mode of N mobile energy storage power supplies to the off-grid mode; when the power protection system is the second parallel capacity increase method, the switch device K1 in the mobile energy storage power supply n (1≤n≤N) is disconnected from a closed state, K2 is closed, and K3 is closed, so as to realize the transformation of N mobile energy storage power supplies from the on-grid mode to the off-grid mode.

[0048] Therefore, according to a power protection system based on parallel connection of multiple mobile energy storage power sources, it can be flexibly connected in parallel to adapt to the power supply and power protection requirements of different loads in multiple scenarios. According to a parallel capacity expansion method of a power protection system, different parallel modes can be selected according to the power of the load to meet the capacity expansion requirements in terms of power and energy. According to a multi-mode operation strategy method of a power protection system, a variety of advanced power electronics and microgrid control technologies are integrated, and the coordinated operation is optimized in different modes to ensure high-quality power supply quality and achieve "zero flicker" on-grid and off-grid switching. Based on the energy storage converter (PCS) technology, the present invention proposes a multi-mobile energy storage parallel technology to realize the functions of multi-machine parallel connection and uninterrupted power protection, meet the different needs of various scenarios such as emergency power supply, backup power supply, temporary power supply, temporary capacity expansion of substations, mobile power banks, etc., and is bound to have broad application prospects in the field of mobile power supply.

[0049] This solves the existing problems in the existing technology. The emergency power supply systems widely used currently include emergency power supply systems with diesel generators and lead-acid batteries as backup, and mobile energy storage systems that combine UPS and lithium iron phosphate battery energy storage technology. However, the disadvantages of diesel generators are that they cannot run at no load for a long time, are noisy, cause exhaust pollution, have large fluctuations in supply voltage and frequency, and are inefficient; the disadvantages of lead-acid batteries are heavy metal pollution, low specific energy, short life, and bulkiness; UPS power protection is difficult to connect in series and parallel, and it is difficult to achieve temporary capacity expansion and other requirements. Compared with different power loads, a single mobile energy storage unit cannot meet all power supply needs.

[0050] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0051] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0052] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0053] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0054] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A multi-mode operation strategy method for a power protection system, characterized in that: include: The power protection system includes a grid-connected switch unit, a mobile energy storage power supply unit and a control unit, wherein the mobile energy storage power supply unit has a parallel cascade auxiliary interface; The grid-connected switch unit is composed of a fast switch or a static switch, a switch branch voltage and current detection unit, and a branch protection; the mobile energy storage power supply is composed of an energy storage battery management system, an energy storage converter, and a switch, and each mobile energy storage power supply is provided with two parallel cascade auxiliary interfaces, and the circuit power of the cascade interface is the parallel number * the rated capacity of the power supply of a single mobile energy storage unit; the control unit is used to monitor, control and protect the power protection system based on multiple mobile energy storage power supplies in parallel; Compare the load power with the power of a single mobile energy storage power source, and determine two different parallel capacity increase methods. The first parallel capacity increase method is that the load power is greater than the power of a single mobile energy storage power source, and the second parallel capacity increase method is that the load power is less than the power of a single mobile power source; When the power protection system adopts the first parallel capacity expansion method, multiple mobile energy storage power sources are connected in parallel in a cascade manner; When the power protection system adopts the second parallel capacity expansion method, multiple mobile energy storage power sources are connected in parallel to the grid bus; When the power supply system adopts the first parallel capacity expansion method, multiple mobile energy storage power supplies are connected in parallel in a cascade manner, including: connecting the third port of mobile energy storage power supply n to the power grid, connecting the fourth port of mobile energy storage power supply n to the third port of mobile energy storage power supply n+1 in sequence, 2≤n+1≤N, and connecting the fourth port of mobile energy storage power supply N to the load; When the load power is less than the power of a single mobile power source, multiple mobile energy storage power sources are connected in parallel to the power grid bus, including: connecting port ② of mobile energy storage power source 1 to load 1, connecting port ② of mobile energy storage power source 2 to load 2, and connecting port ② of mobile energy storage power source n to load n in a sequential manner, 1≤n≤N; Compare the load power with the power of a single mobile energy storage power source, and determine two different parallel capacity increase methods. The first parallel capacity increase method is that the load power is greater than the power of a single mobile energy storage power source, and the second parallel capacity increase method is that the load power is less than the power of a single mobile power source; Determine multiple operating modes of a power protection system based on multiple mobile energy storage power sources in parallel, wherein the multiple operating modes include a grid-connected power protection mode, an off-grid power supply mode, and a grid-connected / off-grid mode; Under multiple operation modes, operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined.

2. The method according to claim 1, characterized in that Under various operation modes, the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined, including: In the grid-connected power supply protection mode, the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined; In the off-grid power supply mode, determining the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method; In the on-grid / off-grid mode, the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined.

3. The method according to claim 2, characterized in that In the grid-connected power supply protection mode, the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined, including: When the power protection system adopts the first parallel capacity expansion method, the switch devices K1 and K2 in the mobile energy storage power supply n, 1≤n≤N, are closed, K3 is disconnected, and the grid-connected switch unit is closed to realize parallel capacity expansion of N mobile energy storage power supplies to meet the power protection needs of high-power loads; When the power protection system adopts the second parallel capacity expansion method, the switch devices K1, K2, and K3 in the mobile energy storage power supply n, 1≤n≤N, are closed to realize parallel capacity expansion of N mobile energy storage power supplies, which are respectively used to protect the power of N small power loads.

4. The method according to claim 2, characterized in that: In the off-grid power supply mode, the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined, including: When the power protection system adopts the first parallel capacity expansion method, the switch devices K1 and K2 in the mobile energy storage power supply n, 1≤n≤N are closed, K3 is disconnected, and the grid-connected switch unit is suspended to realize parallel capacity expansion of N mobile energy storage power supplies to meet the power protection needs of high-power loads; When the power protection system adopts the second parallel capacity expansion method, the switch device K1 in the mobile energy storage power supply n, 1≤n≤N is disconnected, K2 and K3 are closed, and the N mobile energy storage power supplies are respectively connected to the N loads and connected to the grid in parallel to protect the power supply of the N small power loads.

5. The method according to claim 2, characterized in that: In the on-grid / off-grid mode, the operation strategies of the first parallel capacity increase method and the second parallel capacity increase method are determined, including: When the power protection system adopts the second parallel capacity expansion method, the switch devices K1 and K2 in the mobile energy storage power supply n, 1≤n≤N are closed, K3 is disconnected, and the grid-connected switch unit is disconnected from the closed state, so that the grid-connected mode of N mobile energy storage power supplies is transformed into the off-grid mode; When the power protection system adopts the second parallel capacity expansion method, the switch device K1 in the mobile energy storage power supply n, 1≤n≤N is opened from the closed state, K2 is closed, and K3 is closed, so that the N mobile energy storage power supplies are transformed from the grid-connected mode to the off-grid mode.

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