Peak clipping and valley filling photovoltaic energy storage system in general alternating current power supply scene

Abstract

The embodiment of the invention discloses a peak clipping and valley filling photovoltaic energy storage system in a general alternating current power supply scene, which relates to the technical field of electronic power and comprises a peak and valley energy storage system, a photovoltaic system, a mains supply and an original power supply system, the peak-valley energy storage system comprises an energy storage battery unit, a bidirectional DC / DC converter and a bidirectional inverter. The energy storage battery unit is connected with the bidirectional DC / DC converter; the direct current side of the bidirectional inverter is connected with the photovoltaic system and the bidirectional DC / DC converter, the alternating current side of the bidirectional inverter is connected with the mains supply and the original power supply system, and when power generation of the photovoltaic system is excessive, the photovoltaic system can charge the energy storage battery unit through the bidirectional DC / DC converter; when the photovoltaic system is insufficient in power generation, the energy storage battery unit can supply power to the original power supply system through the bidirectional DC / DC converter and the bidirectional inverter, so that the disposal rate of the photovoltaic system can be effectively reduced, and the problem of dislocation of new energy and power utilization peak is solved.

Description

Technical Field

[0001] The present invention relates to the field of electronic power technology, and in particular to a peak shaving and valley filling photovoltaic energy storage system in a general AC power supply scenario. Background Art

[0003] In traditional power systems, energy flows from power plants to users in a one-way manner, with centralized power generation and one-way transmission. In contrast, the new power system supports distributed and flexible energy management modes. In this revolutionary new power system, users are both energy producers and consumers. New energy power generation, mainly photovoltaic and wind power, is mainly powered by DC, while traditional power grids are mainly powered by AC. The transformation and diversity of the roles of power grid users urgently requires a system that integrates AC and DC power supply to break the barriers between AC and DC and achieve seamless connection between new energy and traditional power grids.

[0004] However, the problems of unstable renewable energy power generation, high abandonment rate and misalignment with peak electricity consumption are becoming increasingly prominent.

[0005] The existing new energy power supply system and energy storage system work independently and cannot be coordinated. As a result, the problem of misalignment between new energy and peak electricity consumption cannot be solved, and the joint follow-up operation of new energy, other energy substitution / energy-saving systems, municipal power and energy storage cannot be achieved, and the seamless connection of various systems cannot be achieved. Summary of the invention

[0006] The technical problem to be solved by the embodiments of the present invention is that the existing new energy power supply system and energy storage system work independently and cannot be coordinated, resulting in the problem of misalignment between new energy and peak electricity consumption.

[0007] In order to solve the above problems, an embodiment of the present invention proposes a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario, including a peak-valley energy storage system, a photovoltaic system, a mains power supply and an original power supply system; the peak-valley energy storage system includes an energy storage battery unit, a bidirectional DC / DC converter and a bidirectional inverter; the energy storage battery unit is connected to the bidirectional DC / DC converter; the DC side of the bidirectional inverter is connected to the photovoltaic system and the bidirectional DC / DC converter, and the AC side of the bidirectional inverter is connected to the mains power supply and the original power supply system.

[0008] Its further technical solution is that the peak-valley energy storage system also includes an edge-calculation logic control unit; the bidirectional DC / DC converter, the bidirectional inverter and the energy storage battery unit are connected to the edge-calculation logic control unit and are controlled by the edge-calculation logic control unit.

[0009] A further technical solution is that it also includes an energy-saving system, which is coupled between the mains power and the original power supply system, and the original power supply system and the energy-saving system are connected to the edge computing logic control unit.

[0010] A further technical solution is that it also includes a high-voltage energy storage interface, which is connected to the photovoltaic system, the bidirectional DC / DC converter and the DC side of the bidirectional inverter, and is used to connect to a high-voltage energy storage unit.

[0011] A further technical solution is that it also includes a DC / DC converter, which is connected to the photovoltaic system, the bidirectional DC / DC converter, the high-voltage energy storage interface and the DC side of the bidirectional inverter, and the DC / DC converter is used to connect to a DC power generation device or an electrical load.

[0012] A further technical solution is that the high-voltage energy storage interface includes a power interface, and the power interface is connected to the photovoltaic system, the bidirectional DC / DC converter, the DC / DC converter and the DC side of the bidirectional inverter.

[0013] A further technical solution is that the high-voltage energy storage interface, the photovoltaic system and the DC / DC converter are connected to the edge computing logic control unit.

[0014] A further technical solution is that the high-voltage energy storage interface includes a control interface, and the control interface is connected to the edge computing logic control unit.

[0015] Its further technical solution is that the edge computing logic control unit is used to obtain the power consumption of the original power supply system and the power generation of the photovoltaic system within a preset time period; according to the power consumption of the original power supply system and the power generation of the photovoltaic system, the photovoltaic system is controlled to charge the energy storage battery unit, or the energy storage battery unit is controlled to supply power to the original power supply system.

[0016] A further technical solution is that when the energy storage battery unit supplies power to the original power supply system, the edge computing logic control unit adjusts the load percentage of the energy storage battery unit by adjusting the output voltage of the bidirectional DC / DC converter.

[0017] Compared with the prior art, the technical effects achieved by the embodiments of the present invention include:

[0018] When the photovoltaic system generates excess electricity, the photovoltaic system can charge the energy storage battery unit through the bidirectional DC / DC converter; when the photovoltaic system generates insufficient electricity, the energy storage battery unit can supplement the power supply to the original power supply system through the bidirectional DC / DC converter and the bidirectional inverter, thereby effectively reducing the abandonment rate of the photovoltaic system and solving the problem of misalignment between new energy and peak electricity consumption.

[0019] The peak-shaving and valley-filling photovoltaic energy storage system in the general AC power supply scenario proposed in the embodiment of the present invention can realize the independent charging and discharging of energy storage battery units by each AC / DC system by providing external DC and AC coupling interfaces, and can also break the AC and DC barriers. And through the edge calculation logic control unit, the battery charging and discharging management is made according to the peak and valley timing, meteorological parameters, and load power comprehensive analysis and decision, so that new energy, city power, original power supply system, and other energy-saving systems can be organically linked through the AC and DC coupling interfaces of the energy storage system, suppress new energy fluctuations, and shave peaks and fill valleys, so as to achieve the highest energy utilization rate.

[0020] The peak-shaving and valley-filling photovoltaic energy storage system in the general AC power supply scenario proposed in the embodiment of the present invention can not only work independently, but also can be superimposed with the original power supply systems of households, industry and commerce, communications, photovoltaic systems, and other energy replacement / energy-saving systems (such as cold storage air conditioners / fresh air systems) for joint follow-up work, which can seamlessly realize the corresponding power distribution and backup functions, while embedding clean energy substitution and other energy-saving means. This system has been successfully verified in multiple levels and multiple scenarios in the energy storage of communication base stations, and can achieve 0-100% load adjustable energy storage battery units from the high-voltage side of the DC bus voltage to the low-voltage side of the DC bus (48V, 36V, 12V, etc.) through a bidirectional DC / DC converter 2. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0024] Figure 1A circuit topology diagram of a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0025] Figure 2 Another circuit topology diagram of a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0026] Figure 3 A circuit connection topology diagram between an energy storage battery unit and the mains in a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0027] Figure 4 A circuit connection topology diagram between a high-voltage energy storage unit and the mains in a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0028] Figure 5 A topology diagram of a medium- and low-power bidirectional DC / DC converter of a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0029] Figure 6 A topological diagram of a medium- and low-power bidirectional DC / DC converter working in a BOOST circuit in a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0030] Figure 7 A topological diagram of a medium- and low-power bidirectional DC / DC converter working in a Buck circuit in a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0031] Figure 8 A topology diagram of a high-power bidirectional DC / DC converter of a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention;

[0032] Fig. 9 A topology diagram of a bidirectional inverter of a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario proposed in an embodiment of the present invention.

[0033] Reference numerals

[0034] Peak-valley energy storage system a, DC / DC converter 1, bidirectional DC / DC converter 2, energy storage battery unit 3, edge computing logic control unit 4, bidirectional inverter 5, original power supply system 6, AC power 7, photovoltaic system 8, energy-saving system 9, high-voltage energy storage interface 10, high-voltage energy storage unit 11. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Similar component numbers in the drawings represent similar components. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0037] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0038] See also Figure 1-Figure 9 The embodiment of the present invention proposes a peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario. When the photovoltaic system 8 generates excess electricity, the peak-valley energy storage system a stores the excess electricity of the photovoltaic system 8. When the photovoltaic system 8 generates insufficient electricity, the peak-valley energy storage system a supplements the power supply for the original power supply system 6, thereby effectively reducing the abandonment rate of the photovoltaic system 8 and solving the problem of the misalignment between new energy and peak electricity consumption. The peak-shaving and valley-filling photovoltaic energy storage system in the general AC power supply scenario includes the peak-valley energy storage system a, the photovoltaic system 8, the mains 7 and the original power supply system 6, which are specifically introduced as follows:

[0039] The peak-valley energy storage system a comprises an energy storage battery unit 3, a bidirectional DC / DC converter 2 and a bidirectional inverter 5. The energy storage battery unit 3 is used to complete energy storage and energy release, which is equivalent to a voltage source. Its composition is not limited to chemical energy batteries (lead-carbon batteries, lithium iron phosphate batteries and supercapacitors) and other energy storage batteries. It is a reusable power supply mode.

[0040] The bidirectional DC / DC converter 2 is used to realize bidirectional DC-DC conversion. The bidirectional inverter 5 can convert DC power into AC power, and can also convert AC power into DC power.

[0041] The photovoltaic system 8 is used to convert solar energy into light energy. The original power supply system 6 refers to the load originally powered by the mains 7, which may include AC loads and DC loads, which are not specifically limited in the present invention.

[0042] The energy storage battery unit 3 is connected to the bidirectional DC / DC converter 2; the DC side of the bidirectional inverter 5 is connected to the photovoltaic system 8 and the bidirectional DC / DC converter 2, and the AC side of the bidirectional inverter 5 is connected to the mains 7 and the original power supply system 6.

[0043] Based on the above connection relationship, when the photovoltaic system 8 generates excess electricity, the photovoltaic system 8 can charge the energy storage battery unit 3 through the bidirectional DC / DC converter 2; when the photovoltaic system 8 generates insufficient electricity, the energy storage battery unit 3 can supplement the power supply to the original power supply system 6 through the bidirectional DC / DC converter 2 and the bidirectional inverter 5, thereby effectively reducing the abandonment rate of the photovoltaic system 8 and solving the problem of misalignment between new energy and peak electricity consumption.

[0044] Furthermore, in order to better realize the control of the bidirectional DC / DC converter 2, the bidirectional inverter 5 and the energy storage battery unit 3, in some embodiments of the present invention, the peak-valley energy storage system a also includes an edge-calculating logic control unit 4; the bidirectional DC / DC converter 2, the bidirectional inverter 5 and the energy storage battery unit 3 are connected to the edge-calculating logic control unit 4 and are controlled by the edge-calculating logic control unit 4.

[0045] Specifically, the edge calculation logic control unit 4 is used to control the bidirectional DC / DC converter 2, such as controlling the input / output direction, output power, etc. The edge calculation logic control unit 4 is used to control the bidirectional inverter 5, such as controlling the input / output direction, output power, etc. The edge calculation logic control unit 4 is used to control the energy storage battery unit 3, such as charging / discharging management, etc. The edge calculation logic control unit 4 can be specifically connected to the bidirectional DC / DC converter 2, the bidirectional inverter 5, and the energy storage battery unit 3 through the signal control line. The edge calculation logic control unit 4 is used to control the startup and output of the target module (the bidirectional DC / DC converter 2, the bidirectional inverter 5, the energy storage battery unit 3, the energy-saving system 9, and the DC / DC converter 1, etc.) after the collected analog quantity is converted by A / D and then passed through a preset algorithm. The preset algorithm can be configured by a person skilled in the art, and the present invention is not specifically limited.

[0046] Furthermore, the edge computing logic control unit 4 is used to obtain the power consumption of the original power supply system 6 and the power generation of the photovoltaic system 8 within a preset time period; according to the power consumption of the original power supply system 6 and the power generation of the photovoltaic system 8, the photovoltaic system 8 is controlled to charge the energy storage battery unit 3, or the energy storage battery unit 3 is controlled to supply power to the original power supply system 6.

[0047] Specifically, the edge calculation logic control unit 4 collects the power of the original power supply system 6, and calculates the power consumption of the original power supply system 6 within a preset time period based on the power. At the same time, meteorological parameters (such as light intensity) are collected, and the power generation of the photovoltaic system 8 is calculated based on the meteorological parameters. For example, the power generation of the photovoltaic system 8 within a preset time period under the current meteorological parameters is calculated by the mapping relationship between the preset meteorological parameters and the power generation of the photovoltaic system 8. The amount of power required to be released / stored by the energy storage battery unit 3 is determined based on the power consumption of the original power supply system 6 and the power generation of the photovoltaic system 8. Specifically, if the power consumption of the original power supply system 6 is greater than the power generation of the photovoltaic system 8, the difference between the power consumption of the original power supply system 6 and the power generation of the photovoltaic system 8 is the amount of power required to be released by the energy storage battery unit 3. If the power consumption of the original power supply system 6 is less than the power generation of the photovoltaic system 8, the difference between the power generation of the photovoltaic system 8 and the power consumption of the original power supply system 6 is the amount of power required to be stored by the energy storage battery unit 3.

[0048] When the power consumption is greater than the power generation, the energy storage battery unit 3 is controlled to supply power to the original power supply system 6. When the power consumption is less than the power generation, the photovoltaic system 8 is controlled to charge the energy storage battery unit 3.

[0049] Alternatively, in some embodiments, the edge computing logic control unit 4 is used to manage the charging and discharging of the energy storage battery unit 3 based on a preset peak-valley timing. Specifically, the peak-valley timing includes a peak period and a valley period. During the peak period, if the power generation of the photovoltaic system 8 is greater than the power consumption of the original power supply system 6, the photovoltaic system 8 is controlled to charge the energy storage battery unit 3. During the valley period, if the power generation of the photovoltaic system 8 is less than the power consumption of the original power supply system 6, the energy storage battery unit 3 is controlled to supply power to the original power supply system 6.

[0050] Furthermore, when the energy storage battery unit 3 supplies power to the original power supply system 6, the edge computing logic control unit 4 adjusts the load percentage of the energy storage battery unit 3 by adjusting the output voltage of the bidirectional DC / DC converter 2. The load percentage refers to the ratio of the power supply of the energy storage battery unit 3 to the power consumption of the original power supply system 6.

[0051] Furthermore, the edge computing logic control unit is used to obtain the power consumption forecast value of the original power supply system and the power generation forecast value of the photovoltaic system within a preset time period through a prediction large model, and determine the backup power or remaining capacity of the energy storage battery unit according to the power consumption forecast value and the power generation forecast value.

[0052] Specifically, the prediction model can be specifically an artificial intelligence model, which is pre-trained with training data so that the prediction model has the ability to predict the power consumption forecast value of the original power supply system and the power generation forecast value of the photovoltaic system within a given time period. When the power consumption forecast value is greater than the power generation forecast value, the difference between the power consumption forecast value and the power generation forecast value is the reserve power of the energy storage battery unit (that is, the amount of power that needs to be prepared). The energy storage battery unit prepares the required power in advance to avoid insufficient power when power is needed. When the power consumption forecast value is less than the power generation forecast value, it means that the energy storage battery unit is not needed for power supply. The power generation forecast value minus the power consumption forecast value is the remaining capacity of the energy storage battery unit (that is, the amount of power that can be accommodated), so that it can receive the excess power of the photovoltaic system.

[0053] Furthermore, in order to save energy, the peak-shaving and valley-filling photovoltaic energy storage system in the general AC power supply scenario also includes an energy-saving system 9. The energy-saving system 9 is coupled between the city power 7 and the original power supply system 6, and the original power supply system 6 and the energy-saving system 9 are connected to the edge computing logic control unit 4.

[0054] Specifically, the energy-saving system 9 is used to back up power and supply power to the original power supply system 6, which is controlled by the edge computing logic control unit 4. The energy-saving system 9 can be, for example, a cold storage air conditioning / fresh air system, which is not specifically limited in the present invention.

[0055] The edge computing logic control unit 4 is connected to the original power supply system 6 and the energy-saving system 9 via a signal control line.

[0056] Further, see Figure 2 , and combined with Figure 4 In order to enrich the storage forms of electric energy, the peak shaving and valley filling photovoltaic energy storage system in the general AC power supply scenario also includes a high-voltage energy storage interface 10, which is connected to the photovoltaic system 8, the bidirectional DC / DC converter 2 and the DC side of the bidirectional inverter 5, and the high-voltage energy storage interface 10 is used to connect to the high-voltage energy storage unit 11.

[0057] Specifically, the voltage of the high-voltage energy storage unit 11 can be directly adapted to the voltage of the photovoltaic system 8 without conversion, while the voltage of the energy storage battery unit 3 is lower than the voltage of the photovoltaic system 8, so the bidirectional DC / DC converter 2 is required for conversion. The high-voltage energy storage interface 10 is used to connect the high-voltage energy storage unit 11, so as to realize charging or discharging of the high-voltage energy storage unit 11. The high-voltage energy storage unit 11 may specifically include a high-voltage energy storage battery.

[0058] Furthermore, the peak-shaving and valley-filling photovoltaic energy storage system in the general AC power supply scenario also includes a DC / DC converter 1, which is connected to the photovoltaic system 8, the bidirectional DC / DC converter 2, the high-voltage energy storage interface 10 and the DC side of the bidirectional inverter 5, and the DC / DC converter 1 is used to be connected to a DC power generation device or a power load.

[0059] Specifically, the DC / DC converter 1 can be a unidirectional DC / DC converter or a bidirectional DC / DC converter, which is not specifically limited in the present invention. The DC / DC converter 1 is used to connect to a DC power generation device or an electrical load.

[0060] The DC / DC converter 1 is connected to a DC power generation device, and the DC power generation device can generate electric energy for charging the energy storage battery unit 3 or the high-voltage energy storage unit 11, or for supplying power to the original power supply system 6. The DC power generation device can be, for example, a wind power system.

[0061] The DC / DC converter 1 is connected to an electrical load, and the energy storage battery unit 3, the high-voltage energy storage unit 11 or the photovoltaic system 8 can supply power to the electrical load. The electrical load can be, for example, a load that consumes electrical energy or other energy storage units that can store electrical energy.

[0062] Furthermore, in order to improve the convenience of connection, the high-voltage energy storage interface 10 includes a power interface, which is connected to the photovoltaic system 8, the bidirectional DC / DC converter 2, the DC / DC converter 1 and the DC side of the bidirectional inverter 5.

[0063] Specifically, the power interface is connected to the photovoltaic system 8 , the bidirectional DC / DC converter 2 , the DC / DC converter 1 and the DC side of the bidirectional inverter 5 through a DC power line.

[0064] Furthermore, in order to better control the high-voltage energy storage interface 10 , the photovoltaic system 8 and the DC / DC converter 1 , the high-voltage energy storage interface 10 , the photovoltaic system 8 and the DC / DC converter 1 are connected to the edge computing logic control unit 4 .

[0065] Specifically, the edge computing logic control unit 4 is used to control the photovoltaic system 8 , for example, to control the MPPT module of the photovoltaic system 8 , so as to control the output of the photovoltaic system 8 .

[0066] The edge computing logic control unit 4 is used to control the DC / DC converter 1, for example, to control input / output direction, output power, etc.

[0067] The edge computing logic control unit 4 is connected to the high-voltage energy storage interface 10 , the photovoltaic system 8 and the DC / DC converter 1 through a signal control line.

[0068] The high-voltage energy storage interface 10 includes a control interface, and the control interface is connected to the edge computing logic control unit 4 .

[0069] Specifically, the edge-calculating logic control unit 4 is connected to the control interface via a signal control line, and the control interface is used to connect to the high-voltage energy storage unit 11, so that the edge-calculating logic control unit 4 can control the high-voltage energy storage unit 11 through the control interface, such as control of charge and discharge management.

[0070] Furthermore, the peak-valley energy storage system a includes a DC coupling interface and an AC coupling interface, the DC coupling interface is configured on the DC side of the bidirectional DC / DC converter 2 and the bidirectional inverter 5, and the AC coupling interface is configured on the AC side of the bidirectional inverter 5. The photovoltaic system 8 and the DC / DC converter 1 are connected to the peak-valley energy storage system a through the DC coupling interface. The mains 7 and the original power supply system 6 are connected to the peak-valley energy storage system a through the AC coupling interface.

[0071] The photovoltaic system 8 charges the energy storage battery unit 3 through the DC power line in the peak-valley energy storage system a, and generates electricity through the AC power line through the mains 7. In addition, the photovoltaic system 8, the energy-saving system 9 and the mains 7 can provide combined power supply for the AC and DC loads in the original power supply system 6.

[0072] One end of the DC / DC converter 1 is connected to the photovoltaic system 8, the bidirectional DC / DC converter 2, the high-voltage energy storage interface 10 and the DC side of the bidirectional inverter 5, and the other end of the DC / DC converter 1 can be connected to DC power generation equipment and power loads such as wind power and other energy storage units. The DC power generation equipment, photovoltaic system 8, energy-saving system 9 and city power 7 connected to the DC / DC converter 1 jointly provide combined power supply for the AC and DC loads in the original power supply system 6.

[0073] Furthermore, one end of the bidirectional inverter 5 in the peak-valley energy storage system a is connected to the mains 7, the original power supply system 6 and the energy-saving system 9 through an AC power line, and the other end is connected in parallel to the photovoltaic system 8, the bidirectional DC / DC converter 2 and the DC / DC converter 1 through a DC power line to achieve the following functions: (1) Coupling of power generation equipment (such as the photovoltaic system 8), energy storage equipment (such as the energy storage battery unit 3) and load equipment on the DC power line. (2) Coupling of the power grid, the mains 7, the original AC / DC loads and other AC energy-saving systems 9 on the AC power line.

[0074] Furthermore, one end of the bidirectional DC / DC converter 2 in the peak-valley energy storage system a is connected to the bidirectional inverter 5 through a DC power line and coupled to the external AC power line, and the other end is connected to the energy storage battery unit 3 through a DC power line to achieve the following functions: the energy storage battery unit 3 is stored and released at different voltage levels through the bidirectional DC / DC converter 2. The external AC power line refers to the AC power line on the AC side of the bidirectional inverter 5.

[0075] Furthermore, the core components of the peak-valley energy storage system a include a bidirectional inverter 5, a bidirectional DC / DC converter 2, an energy storage battery unit 3 and an edge-calculation logic control unit 4, which together realize the following functions: (1) Breaking down the barriers between alternating current (AC) and direct current (DC) systems, providing a DC coupling interface for DC power generation units and power consumption units, and providing an AC coupling interface for AC power grids, loads and energy-saving systems 9. (2) The edge-calculation logic control unit 4 predicts the power generation of new energy systems such as photovoltaic and wind power, as well as the power consumption of the load based on the detected meteorological parameters, and then controls the charging and discharging of the energy storage battery unit 3 to suppress the fluctuation of the new energy power generation system. (3) By setting the peak-valley timing segments of specific scenarios in advance, the edge-calculation logic control unit 4 controls the charging and discharging of the energy storage battery unit 3 to achieve peak shaving and valley filling.

[0076] Furthermore, the bidirectional DC / DC converter 2 can be used at low and medium power. Figure 5 The topology circuit works as follows:

[0077] (1) When the input voltage is V1 and the output voltage is V2, and the forward current flows from the V1 side to the V2 side, Figure 5 T2 in the circuit is in the PWM switch working state, and T1 is in the cut-off state and works in the diode form D1. Figure 6 The working status of the BOOST circuit shown;

[0078] (2) When the input voltage is V2 and the output voltage is V1, and the forward current flows from the V2 side to the V1 side, Figure 5 T1 in the circuit is in the PWM switch working state, and T2 is in the cut-off state and works in the diode form D2. Figure 7 The BUCK circuit working status is shown.

[0079] For medium and high voltage DC bus voltages that exceed the safe DC voltage range, large and medium power (10Kw-100Kw level) can be used Figure 8 The topological circuit, Figure 8 The two working arms are arranged symmetrically with the transformer as the center to form a full-bridge or half-bridge circuit. Its working principle is as follows:

[0080] (1) The input voltage is V1, the output voltage is V2, Figure 8 The a1 / a2 and a3 / a4 working arms are in PWM switch working state, and the a5 / a6 and a7 / a8 working arms are in cut-off state, working in diode form. At this time, the circuit is in full-bridge circuit working state with V1 as input and V2 as output;

[0081] (2) The input voltage is V2, the output voltage is V1, Figure 8 The a5 / a6 and a7 / a8 working arms are in PWM switch working state, and the a1 / a2 and a3 / a4 working arms are in cut-off state, working in diode form. At this time, the circuit is in full-bridge circuit working state with V2 as input and V1 as output;

[0082] (3) Figure 8 The positions of the transistors (or MOSFET / IGBT) corresponding to the a3 / a4 and a5 / a6 working arms on both sides of the transformer are replaced with capacitors, and the full-bridge circuit will be transformed into a half-bridge working state.

[0083] Furthermore, the topology diagram of the bidirectional inverter 5 is as follows: Fig. 9 , Fig. 9 The U, V, and W lines are connected in a triangle connection, and the U, V, W, and N lines are connected in a Y-type connection, which is not shown, but does not affect the working principle (the central node n of all branch capacitors in the LC filter circuit is connected to the N line). The working principle is as follows (taking the VW line as an example):

[0084] (1) V1 is the DC input voltage, and the VW line corresponds to T2 as the AC output voltage. At this time, the full bridge circuit is composed of the a1 / a2 arm and the a3 / a4 arm. When a1 and a4 are turned on, a current from W to V and a positive voltage in the same direction appear at T2; and when a2 and a3 are turned on, a current from V to W and a positive voltage in the same direction appear at T2. Using PWM to control the conduction timing of a1, a4 and a2, a3 respectively, the AC voltage and current on the VW line can be realized at T2. The connection method of the LC filter circuit can ensure that it can work normally regardless of whether the triangle or Y connection is used, but the output wires corresponding to the Y connection are changed to VN, WN and UN ( Fig. 9 The middle point n is connected to the N line).

[0085] (2) The VW line corresponds to T2 as the AC input voltage and V1 as the DC output voltage. At this time, the full bridge circuit is still composed of arms a1, a2, a3, and a4. When a positive voltage appears from W to V, a1 and a4 are open; when a positive voltage appears from V to W, a2 and a3 are open; V1 will appear as Fig. 9 The DC voltage marked with positive on top and negative on bottom. Using PWM to control the conduction timing of a1, a4 and a2, a3 respectively, the conduction timing of V1 can be realized. Fig. 9 The DC voltage and current shown. The connection of the LC filter circuit can ensure that it can work properly regardless of whether it is a triangle or Y connection. However, the input wires corresponding to the Y connection are changed to VN, WN and UN ( Fig. 9 The middle point n is connected to the N line).

[0086] In one embodiment, the operation process of the present invention is as follows:

[0087] (1) When the photovoltaic system 8 generates insufficient electricity, the edge computing logic control unit 4 controls the bidirectional DC / DC converter 2 to operate in a boost circuit, so that the photovoltaic system 8 and the energy storage battery unit 3 are combined to supply power, or the photovoltaic system 8 and the mains 7 are combined to supply power.

[0088] (2) When the electricity price is at a valley stage, the edge computing logic control unit 4 controls the photovoltaic system 8 and the mains 7 to supply power in combination.

[0089] (3) When the photovoltaic system 8 generates excess electricity, the edge computing logic control unit 4 controls the bidirectional DC / DC converter 2 to operate in a buck circuit, starts charging the battery, and uses other energy-saving systems 9 for backup power according to actual conditions.

[0090] (4) When the photovoltaic system 8 stops working, the system sets the peak and valley timing in advance through the edge computing logic control unit 4, combines the power supply of the mains 7, and uses other energy-saving systems 9 for backup and discharge according to actual conditions.

[0091] Compared with the prior art, the present invention has the following beneficial effects:

[0092] The peak-shaving and valley-filling photovoltaic energy storage system in the general AC power supply scenario proposed in the embodiment of the present invention can realize the independent charging and discharging of the energy storage battery unit 3 by each AC / DC system by providing a DC / AC coupling interface to the outside, and can also break the AC / DC barriers. And the battery charging and discharging management is made by the edge calculation logic control unit 4 according to the peak-valley timing, meteorological parameters, and load power comprehensive analysis and decision, so that the new energy, the city power 7, the original power supply system 6, and other energy-saving systems 9 can be organically linked through the AC / DC coupling interface of the energy storage system, suppress the fluctuation of new energy, and shave the peak and fill the valley;

[0093] The peak-shaving and valley-filling photovoltaic energy storage system in the general AC power supply scenario proposed in the embodiment of the present invention can not only work independently, but also can be superimposed with the original power supply systems of households, industry and commerce, communications, etc., photovoltaic systems 8, and other energy replacement / energy-saving systems 9 (such as cold storage air conditioners / fresh air systems) for joint follow-up work, which can seamlessly realize the corresponding power distribution and backup functions, while embedding clean energy substitution and other energy-saving means. This system has been successfully verified in multiple levels and multiple scenarios in the energy storage of communication base stations, and can achieve 0-100% load adjustable energy storage battery units from the high-voltage side of the DC bus voltage to the low-voltage side of the DC bus (48V, 36V, 12V, etc.) through a bidirectional DC / DC converter 2.

[0094] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0095] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0096] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0097] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0098] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0099] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0100] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0101] The above is a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario, characterized in that: It includes a peak-valley energy storage system, a photovoltaic system, a mains power supply and an original power supply system; the peak-valley energy storage system includes an energy storage battery unit, a bidirectional DC / DC converter and a bidirectional inverter; the energy storage battery unit is connected to the bidirectional DC / DC converter; the DC side of the bidirectional inverter is connected to the photovoltaic system and the bidirectional DC / DC converter, and the AC side of the bidirectional inverter is connected to the mains power supply and the original power supply system.

2. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 1 is characterized in that: The peak-valley energy storage system also includes an edge-calculation logic control unit; the bidirectional DC / DC converter, the bidirectional inverter and the energy storage battery unit are connected to the edge-calculation logic control unit and are controlled by the edge-calculation logic control unit.

3. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 2 is characterized in that: It also includes an energy-saving system, which is coupled between the mains power and the original power supply system. The original power supply system and the energy-saving system are connected to the edge computing logic control unit.

4. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 2 is characterized in that: It also includes a high-voltage energy storage interface, which is connected to the photovoltaic system, the bidirectional DC / DC converter and the DC side of the bidirectional inverter, and is used to connect to a high-voltage energy storage unit.

5. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 4 is characterized in that: It also includes a DC / DC converter, which is connected to the photovoltaic system, the bidirectional DC / DC converter, the high-voltage energy storage interface and the DC side of the bidirectional inverter, and the DC / DC converter is used to connect to a DC power generation device or an electrical load.

6. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 5 is characterized in that: The high-voltage energy storage interface includes a power interface, and the power interface is connected to the photovoltaic system, the bidirectional DC / DC converter, the DC / DC converter and the DC side of the bidirectional inverter.

7. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 5, characterized in that: The high-voltage energy storage interface, the photovoltaic system and the DC / DC converter are connected to the edge computing logic control unit.

8. The peak-shaving and valley-filling photovoltaic energy storage system in a universal AC power supply scenario according to claim 7, characterized in that: The high-voltage energy storage interface includes a control interface, and the control interface is connected to the edge computing logic control unit.

9. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 2, characterized in that: The edge computing logic control unit is used to obtain the power consumption of the original power supply system and the power generation of the photovoltaic system within a preset time period; control the photovoltaic system to charge the energy storage battery unit according to the power consumption of the original power supply system and the power generation of the photovoltaic system, or control the energy storage battery unit to power the original power supply system.

10. The peak-shaving and valley-filling photovoltaic energy storage system in a universal AC power supply scenario according to claim 2, characterized in that: The edge computing logic control unit is used to obtain the power consumption forecast value of the original power supply system and the power generation forecast value of the photovoltaic system within a preset time period through a prediction large model, and determine the backup power or remaining capacity of the energy storage battery unit according to the power consumption forecast value and the power generation forecast value.

11. The peak-shaving and valley-filling photovoltaic energy storage system in a general AC power supply scenario according to claim 9, characterized in that: When the energy storage battery unit supplies power to the original power supply system, the edge computing logic control unit adjusts the load percentage of the energy storage battery unit by adjusting the output voltage of the bidirectional DC / DC converter.

12. The peak-shaving and valley-filling photovoltaic energy storage system in a universal AC power supply scenario according to claim 9, characterized in that: The edge computing logic control unit is used to control the startup and output of the target module after the collected analog quantity is converted by A / D and then passes through a preset algorithm. The target module includes a bidirectional DC / DC converter, a bidirectional inverter, an energy storage battery unit, an energy-saving system and a DC / DC converter; The edge calculation logic control unit is also used to collect the power of the original power supply system, and calculate the power consumption of the original power supply system within a preset time period based on the power of the original power supply system; Collect meteorological parameters and calculate the power generation of the photovoltaic system within a preset time period based on the meteorological parameters; The amount of electricity that the energy storage battery unit needs to release / store is determined based on the power consumption of the original power supply system and the power generation of the photovoltaic system.

13. The peak-shaving and valley-filling photovoltaic energy storage system in a universal AC power supply scenario according to claim 1, characterized in that: One end of the bidirectional DC / DC converter in the peak-valley energy storage system is connected to the bidirectional inverter through a DC power line and coupled to the external AC power line, and the other end is connected to the energy storage battery unit through a DC power line to achieve the following functions: storing and releasing electrical energy in the energy storage battery unit at different voltage levels through the bidirectional DC / DC converter.

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