WO2017076192A1 - Home nano-network system and community-level microgrid system - Google Patents

Abstract

A home nano-network system and a community-level microgrid system, the community-level microgrid system comprising a plurality of home nano-network systems, each home nano-network system comprising new energy power utilization equipment (11), a new energy power generation system (12), a bidirectional DC/DC (13) and an energy storage battery (14), a DC bus of the new energy power utilization equipment (11) being connected to a household appliance (10). The DC bus of the new energy power utilization equipment (11) can be directly connected to the DC electric energy drive of the new energy power generation system (12), omitting, compared with the conventional mode, an inversion process for current. Therefore, compared with supplying power directly using the new energy power generation system (12), supplying power to the household appliance (10) using the DC bus of the new energy power utilization equipment (11) can omit multiple current transformation conversions, thereby improving the utilization rate of the energy.

Description

Home network system and community-level microgrid system

This application claims priority to Chinese Patent Application No. 201510746334.8, entitled "Family Network System and Community Level Microgrid System" on November 4, 2015, the entire contents of which are incorporated by reference. In this application.

Technical field

The present invention relates to the field of power system technologies, and more particularly to a home network system and a community level micro grid system.

Background technique

Micro-grid refers to a small-scale power distribution system that can be self-controlled, protected and managed by distributed power sources, energy storage devices, power electronic devices, loads and protection devices. The microgrid can be operated in parallel with the large grid. When the energy is insufficient, energy can be absorbed from the large grid. When the energy is sufficient, the energy can be fed back to the large grid. When a large power grid fails, the microgrid can operate independently and continuously supply power to the load in the area, thereby improving power supply reliability. Among them, the electric energy transmitted in the form of AC is an AC microgrid, and the DC microgrid is transmitted in the form of DC.

The structure of the existing typical DC microgrid is shown in Figure 1. Photovoltaic 01 is connected to the DC bus through DC/DC (DC converter) 001, and Wind Energy 02 is connected to DC through AC/DC (AC-DC converter) 002. The busbar, the energy storage device 03 is connected to the DC bus via DC/DC003, and then connected to the large grid 04 via a separate AC/DC004. The DC microgrid supplies power to the AC load 05 via a DC/AC (DC-AC converter) 005, or the DC load 06 via DC/DC 006, or directly to the DC load 07. However, for some household appliances that cannot directly utilize the DC load of the DC microgrid, the conversion from DC to AC and then to DC is required, that is, an additional inverter device is required. The current application of AC microgrid is relatively common. When powering household appliances, new energy sources such as photovoltaics need to undergo multiple changes to meet the power supply requirements.

In summary, it can be seen that the new energy needs to undergo multiple converter conversions when powering the household appliances. Therefore, the power loss is large and the energy utilization efficiency is not high.

Summary of the invention

In view of this, the present invention provides a home network system and a community-level micro grid system to improve energy utilization when power is supplied to household appliances by using new energy sources.

A family network system, including:

a new energy power device having a DC bus that can be connected to a home appliance and can supply power to the home appliance;

a new energy power generation system connected to the new energy power equipment;

Bidirectional DC/DC;

An energy storage battery that can be charged and discharged under the control of the bidirectional DC/DC by the bidirectional DC/DC accessing the DC bus.

Preferably, the method further includes:

The input terminal is connected to the DC bus, and the output terminal is connected to the home appliance, and the bus voltage can be converted into a DC/DC of a voltage level that can be directly utilized by the home appliance.

Preferably, the method further includes:

Charging pile;

The vehicle battery is connected to the AC bus through the charging post, and can be charged and discharged under the control of the charging post.

Preferably, the new energy power generation system is connected to the DC bus.

Preferably, the new energy electrical equipment is a photovoltaic air conditioner.

A community-level microgrid system includes: a plurality of home network systems, wherein each of the household nano-network systems has a DC bus side interconnection and an AC side interconnection.

As can be seen from the above technical solution, the present invention provides a home network system and a community-level micro grid system. The community-level micro grid system includes a plurality of home network systems, and each family network system includes new energy power. Equipment, new energy generation systems, two-way DC/DC and energy storage batteries, DC busbars for new energy consumers are connected to household appliances. The DC bus of the new energy power equipment can be directly connected to the DC power of the new energy power generation system. Compared with the traditional, the current inversion process is omitted. Therefore, compared with the direct power supply of the new energy generation system, the home appliance adopts the DC bus power supply of the new energy power equipment, which can save multiple energy conversions, thereby improving energy utilization.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is an embodiment of the present invention, and it is not harmful to those skilled in the art. On the premise of creative labor, other drawings can also be obtained from the drawings provided.

1 is a schematic structural diagram of a DC microgrid disclosed in the prior art embodiment;

2 is a schematic structural diagram of a home network system according to an embodiment of the present invention;

3 is a schematic structural diagram of another home network system according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a community-level microgrid system according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The embodiment of the invention discloses a home network system and a community-level micro grid system, so as to improve energy utilization when using new energy to supply power to household appliances.

Referring to FIG. 2, an embodiment of the present invention discloses a structure of a home network system, including:

New energy consumer equipment 11, new energy power generation system 12, bidirectional DC/DC (ie bidirectional DC converter) 13 and energy storage battery 14;

among them,

The new energy consumer 11 has a DC bus that can be connected to the home appliance 10 and can supply power to the home appliance 10.

The new energy power generation system 12 is connected to the new energy power equipment 11 for supplying electric energy to the new energy power equipment 11.

It should be noted that the DC bus of the new energy consumer equipment 11 can be directly connected to the DC current of the new energy source, and the inverter can be omitted compared with the conventional DC-AC-DC.

The energy storage battery 14 is connected to the DC bus through the bidirectional DC/DC 13 and can be charged and discharged under the control of the bidirectional DC/DC 13.

Wherein, when the electric energy generated by the new energy power generation system 12 can meet the electricity demand of the household appliance 10 and has a surplus, the new energy power generation system 12 preferentially charges the energy storage battery 14 through the bidirectional DC/DC 13 and then passes through the DC/AC after being fully charged ( The DC-AC converter is connected to the AC power grid; when the power generated by the new energy power generation system 12 cannot meet the power demand of the household appliance 10, the energy storage battery 14 supplies power to the home appliance 10, and when the energy storage battery 14 is SOC ( State of Charge, when the load state is below the preset threshold, for protection The energy storage battery 14 is not damaged, and at this time, the home appliance 10 is powered by the AC power grid.

In summary, it can be seen that the DC bus of the new energy power equipment 11 can be directly connected to the DC power of the new energy power generation system 12, which saves the current inversion process. Therefore, the home appliance 10 uses the DC bus power supply of the new energy power device 11 to save multiple energy conversions compared with the power supply directly using the new energy power generation system 12, thereby improving energy utilization.

At present, most of the household appliances on the market are powered by a DC power supply. The DC bus in this application directly supplies power to the household appliance 10, which can eliminate the internal rectifier circuit of the household appliance 10, thereby reducing the converter conversion and improving the energy utilization rate. At the same time, as far as the household appliance 10 itself is concerned, the cost of the rectifier circuit can also be saved.

Preferably, the new energy power equipment 11 is a photovoltaic air conditioner, and the new energy power generation system 12 is a photovoltaic power generation system.

The new energy power generation system 12 is connected to the new energy consumer equipment 11 via a DC bus.

It should be noted that when the voltage level of the DC bus is suitable for the household appliance 10, the household appliance 10 is directly connected to the DC bus; when the voltage level of the DC bus is not suitable for the household appliance 10, the household appliance 10 is connected to the DC bus through the DC/DC. .

Therefore, in order to further optimize the above embodiment, referring to FIG. 3, a schematic diagram of a structure of a home network system according to another embodiment of the present invention, further comprising: DC/DC15 on the basis of the embodiment shown in FIG.

The input of the DC/DC 15 is connected to the DC bus, and the output is connected to the home appliance 10, and the DC/DC 15 can convert the bus voltage into a voltage level that can be directly utilized by the home appliance 10.

To further optimize the above embodiment, further comprising: a charging post 16 and a car battery 17;

The vehicle battery 17 is connected to the AC bus through the charging post 16, and can be charged and discharged under the control of the charging post 16.

among them,

The charging pile 16 is similar in function to the fuel dispenser inside the gas station. It can be fixed on the ground or wall, installed in public buildings (public buildings, shopping malls, public parking lots, etc.) and residential parking lots or charging stations, depending on the voltage. The level is charged for various types of electric vehicles. The input end of the charging post 16 is directly connected to the AC power grid, and the output end is equipped with a charging plug for charging the electric vehicle.

Therefore, when the SOC of the energy storage battery 14 is lower than a preset threshold, the automobile battery 17 can serve as a supplement to the energy storage battery 14, and continue to supply power to the home appliance 10, thereby further improving the power supply reliability of the home network system.

It should be noted that the supplementary battery includes not only the automobile battery 17 but also the battery.

The independent home network system generally has a single energy storage battery 14. Since the capacity of the energy storage battery 14 is small, it cannot meet the long-term independent operation of the home network system. In response to this shortcoming, the present invention also provides a community-level microgrid system.

Referring to FIG. 4, a schematic structural diagram of a community-level microgrid system disclosed in an embodiment of the present invention includes: multiple home network systems (only two are shown in FIG. 3, respectively, a home network system 31 and a home network) System 32), the DC bus side of the new energy power equipment in each family network system is interconnected, and the AC side is interconnected.

It can be seen that the community-level microgrid system provided by the present invention forms a distributed energy storage structure by interconnecting multiple home network systems, and each energy storage battery 14 complements each other to increase the energy storage of the community-level microgrid system. The total energy ensures that important loads in the community-level microgrid can operate independently for long periods of time.

By interconnecting the DC bus side of the new energy power equipment in multiple home network systems and interconnecting the AC side, an AC/DC dual network hybrid microgrid system is formed, because a small number of appliances such as a rotating electrical machine load in the household appliance 10 are used for communication. Power is supplied, so the AC network can be used as a supplement to the DC network, thereby increasing the reliability of the entire microgrid system.

It should be noted that in order to improve the economics of the overall operation of the microgrid system, a large number of dispersed energy storage batteries 14 preferentially supply power to the nearby household appliances.

Finally, it should also be noted that in this context, relational terms such as first and second are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these entities. There is any such actual relationship or order between operations. Furthermore, the term "comprises" or "comprises" or "comprises" or any other variations thereof is intended to encompass a non-exclusive inclusion, such that a process, method, article, or device that comprises a plurality of elements includes not only those elements but also Other elements, or elements that are inherent to such a process, method, item, or device. In the absence of more restrictions, the elements defined by the statement "including one..." are not There are additional identical elements that are excluded from the process, method, article, or device that includes the described elements.

The various embodiments in the present specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same similar parts between the various embodiments may be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but the scope of the invention is to be accorded

Claims (6)

1. A family network system, characterized in that it comprises:

   a new energy power device having a DC bus that can be connected to a home appliance and can supply power to the home appliance;

   a new energy power generation system connected to the new energy power equipment;

   Bidirectional DC/DC;

   An energy storage battery that can be charged and discharged under the control of the bidirectional DC/DC by the bidirectional DC/DC accessing the DC bus.
2. The home network system according to claim 1, further comprising:

   The input terminal is connected to the DC bus, and the output terminal is connected to the home appliance, and the bus voltage can be converted into a DC/DC of a voltage level that can be directly utilized by the home appliance.
3. The home network system according to claim 1, further comprising:

   Charging pile;

   The vehicle battery is connected to the AC bus through the charging post, and can be charged and discharged under the control of the charging post.
4. The home network system of claim 1 wherein said new energy generation system is coupled to said DC bus.
5. The home network system according to claim 1, wherein the new energy consumer device is a photovoltaic air conditioner.
6. A community-level microgrid system, comprising: a plurality of home network systems, wherein each of the household nano-network systems has a DC bus side interconnection and an AC side interconnection.

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