Bidirectional converter and energy management system

Abstract

The utility model relates to the technical field of converters, in particular to a bidirectional converter and an energy management system. The bidirectional converter comprises a shell, and a rectifier, an inverter, a filter, a control unit and an energy router which are arranged in the shell, the rectifier is electrically connected with the inverter, and the filter is arranged at the output end of the inverter; the control unit is electrically connected with the rectifier, the inverter and the filter at the same time; the control unit is electrically connected with the energy router for data interaction, and the energy router is used for controlling conversion of alternating current and direct current. Because the energy router is embedded in the bidirectional converter, when the energy management system is constructed, space does not need to be reserved for the energy router, the installation of the energy router is directly completed by directly installing the bidirectional converter, and an installation position does not need to be reserved for the energy router, so that the occupied area of the device is reduced; the installation and construction processes are simplified, and the construction cost of the energy management system is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of converters, and particularly relates to a bidirectional converter and an energy management system. Background Technique

[0002] With the proposal of the dual-carbon goal, the energy management system plays an important role in researching energy routing strategies. The energy management system not only controls the reasonable distribution of energy to improve the rationality of energy use and the energy utilization rate, but also controls the trigger circuit for turning on and off the power switch elements during the mutual conversion between alternating current and direct current.

[0003] The energy management system generally consists of a photovoltaic device, a storage device, an energy router, a converter, etc. Among them, the bidirectional converter realizes the conversion between alternating current and direct current, and the energy router is used to realize the routing of energy. When constructing the energy management system, it is necessary to install the energy router and the converter separately and reserve enough installation area, resulting in a relatively high overall cost, a large floor area, and complex installation and construction work for the energy management system. Content of the Utility Model

[0004] The purpose of the utility model is to provide a bidirectional converter and an energy management system to reduce the construction cost of the energy management system and reduce the floor area.

[0005] To solve the above technical problems, the utility model provides a bidirectional converter, which includes a housing and a rectifier, an inverter, a filter, a control unit, and an energy router arranged in the housing. The rectifier is electrically connected to the inverter, and the filter is arranged at the output end of the inverter; the rectifier is used to convert alternating current into direct current; the inverter is used to convert direct current into alternating current; the filter is used to eliminate harmonics and improve the current quality; the control unit is electrically connected to the rectifier, the inverter, and the filter at the same time;

[0006] The control unit is electrically connected to the energy router for data interaction, and the energy router is used to control the conversion between alternating current and direct current.

[0007] Further, an optical fiber port is arranged on the control unit, and the optical fiber port is used to connect with an optical fiber.

[0008] Further, the control unit and the energy router perform data interaction through a serial communication interface.

[0009] Further, the control unit includes a processor, a memory, and a serial communication interface. The processor is used to execute control algorithms, process data, and guide system operations. The memory is used to store operation programs, data, and intermediate results. The serial communication interface is used to perform data interaction with the energy router.

[0010] Further, the processor is a microprocessor or a digital signal processor.

[0011] Further, the bidirectional converter further includes a battery pack for supplying power to the bidirectional converter.

[0012] Further, the battery pack is a storage battery pack.

[0013] Further, the bidirectional converter further includes a protection device, which includes a protection circuit for cutting off the power supply and limiting the current in case of an abnormal situation.

[0014] The present utility model also provides an energy management system, including a power generation system, an energy storage device, and a bidirectional converter as described in any one of the above technical solutions.

[0015] Further, there are multiple bidirectional converters, and optical fibers are connected between the energy routers of two adjacent bidirectional converters for communication.

[0016] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0017] Since the energy router is embedded in the bidirectional converter, when constructing the energy management system, there is no need to reserve space for the energy router. Directly installing the bidirectional converter completes the installation of the energy router, eliminating the need to reserve an installation position for the energy router. This reduces the floor area of the device, simplifies the installation and construction process, and reduces the construction cost of the energy management system. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of an embodiment of the bidirectional converter of the present utility model with part of the housing hidden;

[0019] Figure 2 is another perspective schematic structural diagram of an embodiment of the bidirectional converter of the present utility model with part of the housing further hidden;

[0020] Figure 3 is a topology diagram of an embodiment of the bidirectional converter of the present utility model;

[0021] Figure 4 is Figure 1 a state diagram when the bidirectional converter in Description of the Drawings:

[0023] 10. Housing; 20. Rectifier; 30. Inverter; 40. Filter; 50. Control unit; 51. Optical fiber port; 60. Energy router. Detailed implementation manners

[0024] The two-way converter and energy management system of the present utility model will be described below in conjunction with the schematic diagrams, in which the preferred embodiments of the present utility model are shown. It should be understood that those skilled in the art can modify the present utility model described herein while still achieving the advantageous effects of the present utility model. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation on the present utility model.

[0025] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any sequential or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, both include direct and indirect connection (coupling). In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present utility model.

[0026] In the present utility model, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0027] The present utility model will be described more specifically by way of example in the following paragraphs with reference to the drawings. The advantages and features of the present utility model will be clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise scales, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present utility model.

[0028] The following will be combined with the drawings of the specification Figure 1 to the appended Figure 4 as shown, the two-way converter of the present utility model will be described.

[0029] In one of the embodiments, as Figure 1 , Figure 2 and Figure 3As shown in the figure, the bidirectional converter includes a housing 10, and a rectifier 20, an inverter 30, a filter 40, a control unit 50, and an energy router 60 disposed in the housing 10. The rectifier 20 and the inverter 30 are electrically connected, and the filter 40 is disposed at the output end of the inverter 30. The rectifier 20 is used to convert alternating current into direct current. The inverter 30 is used to convert direct current into alternating current. The filter 40 is used to eliminate harmonics and improve current quality. The control unit 50 is electrically connected to the rectifier 20, the inverter 30, and the filter 40 at the same time.

[0030] The control unit 50 is electrically connected to the energy router 60 for data interaction, and the energy router 60 is used to control the conversion between alternating current and direct current.

[0031] Since the energy router 60 is embedded in the bidirectional converter, when constructing the energy management system, there is no need to reserve space for the energy router 60. Directly installing the bidirectional converter directly completes the installation of the energy router 60, and there is no need to reserve an installation position for the energy router 60, thus reducing the floor area of the device, simplifying the installation and construction process, and reducing the construction cost of the energy management system.

[0032] In one embodiment, as Figure 2 shown, a fiber optic port 51 is provided on the control unit 50. As Figure 4 shown, using the fiber optic port 51, the bidirectional converter can communicate with other bidirectional converters through optical fibers. Among them, TI and T2 are 630 kVA transformers. The 10 kV high-voltage alternating current is stepped down to 400 V alternating voltage after being transformed by transformers T1 and T2, and then becomes 750 V direct current after being transformed by the bidirectional transformer of the present invention. Usually, cables are used for data communication between the various modules of the existing energy management system, and the transmission speed is low and the quality is poor. However, optical fiber communication has low delay, high speed, strong anti-interference ability, and low loss.

[0033] Compared with the prior art, in the case of the same communication distance, the bidirectional converter of the present invention can significantly reduce the communication time. The comparison table of communication time consumption (seconds) is as follows:

[0034] Table 1

[0035] Communication distance (meters) 50 meters 100 meters 150 meters 200 meters 250 meters 300 meters Cable time consumption (seconds) 12.4 14.1 15.8 16.4 17.8 20.1 Optical fiber time consumption (seconds) 0.9 2.35 5.5 8.4 9.0 10.5

[0036] In one embodiment, the control unit 50 and the energy router 60 perform data interaction through a serial communication interface. For example, data interaction is performed through RS-232 or RS-485. In other embodiments, data exchange can also be performed through Ethernet.

[0037] In one embodiment, the control unit 50 includes a processor, a memory, and a serial communication interface. The processor is used to execute control algorithms, process data, and guide system operations. The processor can adopt the Cyclone IV series processor produced by Altera Corporation. The memory is used to store operation programs, data, and intermediate results. The serial communication interface is used to interact with the energy router 60 for data. Specifically, the memory can be a read-only memory (ROM), a random access memory (RAM), a flash memory (Flash), etc. The processor is a microprocessor or a digital signal processor (DSP). The control unit 50 is responsible for the control and management of the entire bidirectional converter. By detecting parameters such as input voltage, input current, and output voltage, the control unit 50 can adjust the switching frequency and duty cycle of the inverter 30, thereby achieving the control of the output alternating current. Common control strategies include PWM (pulse width modulation), PFM (pulse frequency modulation), etc.

[0038] In one embodiment, the bidirectional converter further includes a battery pack. The battery pack is used to supply power to the bidirectional converter and is usually composed of multiple battery cells connected in series or in parallel. The battery pack can store electrical energy and provide power when needed. For example, when the energy generated by the solar photovoltaic panel or the wind turbine is insufficient, the battery pack can release the stored electrical energy to maintain the continuous power supply of the system. The battery pack can also serve as an emergency backup power supply to provide power for critical loads in the case of main power failure or power outage. Preferably, the battery pack can be a storage battery pack.

[0039] In one embodiment, the bidirectional converter further includes a protection device. The protection device includes a protection circuit. The protection circuit is used to cut off the power supply and limit the current in case of abnormal conditions. Specifically, the protection circuit is used to monitor the working state of the bidirectional converter. When an abnormal condition (such as overvoltage, undervoltage, overcurrent, short circuit, etc.) occurs, the protection circuit will immediately take measures such as cutting off the power supply and limiting the current to protect the safety of equipment and personnel.

[0040] This application also provides an energy management system.

[0041] The energy management system of this embodiment includes a power generation system, an energy storage device, and the bidirectional converter as described in any one of the above embodiments.

[0042] Specifically, the power generation system can be a solar photovoltaic power generation system or a wind power generation system. The energy storage device is used to store electricity for use when needed. The structure of the bidirectional converter has been introduced in the above embodiments and will not be elaborated here.

[0043] In one of the embodiments, there are multiple bidirectional converters, and optical fibers are connected between the energy routers 60 between two adjacent bidirectional converters for communication. Optical fiber communication has low delay, high speed, strong anti-interference ability and low loss.

[0044] Obviously, those skilled in the art can make various changes and modifications to the present utility model without departing from the spirit and scope of the present utility model. Thus, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and its equivalent technologies, the present utility model is also intended to include these changes and modifications.

Claims

1. A bidirectional converter, characterized in that: The invention comprises a housing and a rectifier, an inverter, a filter, a control unit and an energy router arranged in the housing, wherein the rectifier is electrically connected to the inverter, and the filter is arranged at the output end of the inverter; the rectifier is used to convert AC power into DC power; the inverter is used to convert DC power into AC power; the filter is used to eliminate harmonics and improve current quality; and the control unit is electrically connected to the rectifier, the inverter and the filter at the same time; The control unit is electrically connected to the energy router for data exchange, and the energy router is used to control the conversion of alternating current and direct current.

2. The bidirectional converter according to claim 1, characterized in that: The control unit is provided with an optical fiber port, and the optical fiber port is used for connecting to an optical fiber.

3. The bidirectional converter according to claim 1, characterized in that: The control unit and the energy router exchange data via a serial communication interface.

4. The bidirectional converter according to claim 1, characterized in that: The control unit includes a processor, a memory and a serial communication interface. The processor is used to execute control algorithms, process data and guide system operations. The memory is used to store operating programs, data and intermediate results. The serial communication interface is used to exchange data with the energy router.

5. The bidirectional converter according to claim 4, characterized in that: The processor is a microprocessor or a digital signal processor.

6. The bidirectional converter according to claim 1, characterized in that: The bidirectional converter further includes a battery pack, and the battery pack is used to supply power to the bidirectional converter.

7. The bidirectional converter according to claim 6, characterized in that: The battery pack is a storage battery pack.

8. The bidirectional converter according to claim 1, characterized in that: The bidirectional converter further comprises a protection device, wherein the protection device comprises a protection circuit, and the protection circuit is used for cutting off power supply and limiting current when an abnormal situation occurs.

9. An energy management system, characterized in that: The invention comprises a power generation system, an energy storage device and a bidirectional converter as claimed in any one of claims 1 to 8.

10. The energy management system according to claim 9, characterized in that: There are multiple bidirectional converters, and the energy routers of two adjacent bidirectional converters are connected with optical fibers for communication.

Images