KR102107483B1 - IoT hybrid micro grid system - Google Patents

Abstract

According to an IoT hybrid micro grid system of the present invention, the electricity cost can be significantly reduced through self-appropriation of electric power in a corresponding area, the problem of power shortage and quality degradation can be solved by adopting a hybrid method that uses both distributed power and grid-connected power, power can be used without blackout by using residual power of an ESS and additional electricity production of the distributed power even when the power supply of the grid connection is unstable or is cut off since the ESS has a minimum charge amount above a certain level, the power can be more stably used by increasing the level of the minimum charge amount of the ESS in advance when the blackout is expected, energy resources can be collectively managed when monitoring and or controlling the micro grid system, users of facilities can collect, predict, and optimize field operation information, the technology that optimizes energy use, responds to changes in power demand, and monitors the status of inverters and ESS in real time can be applied by using IoT, and the control of the micro grid system through the IoT can be applied to and utilized in a smart building automation system. The IoT hybrid micro grid system includes a solar power generation device, a wind power generator, a hybrid inverter unit, a controller, an ESS, a control server, a user, and a power line system.

Description

IoT hybrid micro grid system {IoT hybrid micro grid system}

The present invention relates to an IoT hybrid micro-grid system, and more specifically, to generate electricity by installing a hybrid power generator that generates electricity from a plurality of distributed power sources such as solar or wind power in a certain area, such as a house or apartment, In constructing a micro grid system that uses electricity by storing it in an ESS (Energy Storage System), when the charge amount of the ESS or the power generation amount of the hybrid power generation unit is insufficient, an uninterruptible power supply (UPS) function is used to connect to an external system. When the electricity is supplied through the connection, it is stored in the ESS and the user can use the electricity.If the charging amount of the ESS or the electric power generation of the hybrid power generator is sufficient, the connection to the external system is separated and only the electric furnace produced by the hybrid power generator has a certain area. To power, and the hybrid It relates to an IoT hybrid micro-grid system that can wirelessly control management, such as monitoring of a power system including a power generation device and an ESS, through a user's smartphone at a remote location or other devices connected online.

In general, a micro grid system is a system that supplies electricity to a range of areas using electricity produced from a distributed power source independent of a wide-area power system connected to the grid. Recently, renewable energy such as solar, wind, hydro, geothermal With the expansion of the utilization of circles and the development of ESS technology, technology development and installation are increasing worldwide, and in many countries such as islands, remote areas, desert areas, or countries that are pursuing post nuclear power plants such as Germany, micro grid systems It is promoting the introduction more actively. The micro grid system has relatively little construction period and investment cost, so it is possible to secure economics and form a market in the early stage. In Korea, microgrid construction in island regions such as energy self-reliance islands is predominant, and university campuses and industries However, if the scope of hospitals, military units, etc. is expanded to the community level, the market is expected to grow very rapidly, and if the built-up microgrid of the community level is expanded to the nationwide level and linked to the wide-area power system in the future, the smart grid will be built nationwide. Can be.

The advantages of the micro grid system include long-term cost reduction and eco-friendly features, and maintenance of independence by operating separately from the wide-area power system. On the other hand, the disadvantages are high initial installation cost and increased power consumption during a specific period. Or, in the case of a consumer with high power consumption, there is an instability of electricity supply, which may cause a power shortage due to the power demand exceeding the power supply.

As a conventional technique for solving this problem, Korean Patent No. 10-1402340 (Registration Date: May 26, 2014), which was devised to have the advantages of microgrid system and grid connection at the same time, is a joint use of solar energy and wind power. By using renewable power accumulated through solar and wind power, the new and renewable combined power generation system of the house can reduce electricity bills in apartments and rapidly turn it into a system (KEPCO side power) when exhausted electricity is exhausted. As a main invention, a solar power generation unit 100 installed in an apartment house and absorbing light energy from the sun and converting it into electrical energy: a wind power generator 200 installed in an apartment house and converting wind energy into electric energy: a common house A shaft that is installed in a house and stores electricity generated from the photovoltaic power generation unit 100 and the wind power generation unit 200, respectively, and is connected to the power line conversion device 400 via a battery side electric wire L1. Battery 300: T-shaped as a whole, the inside is penetrated into a T-shaped, and the upper surface is provided with a housing 411 made of an insulating material having a guide portion 411a communicating with the inside, and a connection hooking hole 412a at the upper end. , It is mounted on the housing 411, the distribution line (L3) is provided with a conductive material distribution line connection 412 is fixed to be connectable, one end having a guide surface (413a), on both sides of the housing 411 penetrated in the longitudinal direction Inserted and fixed to the other end, the battery side electric wire L1 and the first electric power front electric wire L2 are respectively inserted and fixed in a pair of power line connection ports 413 and the housing 411, so that the upper surface of the power distribution line connection port 412 is installed. A connector body 410 having a bullet flake 414 to fire in the direction; A motor 421 having a screw 421a on one side, installed on the housing 411, and controlled by the control unit 600 to rotate in the forward or reverse direction, the upper end is installed on the screw 421a, and the lower end is guided. The transfer block 422 of an insulating material that penetrates through the portion 411a and is disposed inside the housing 411, one side is horizontally installed at the lower end of the transfer block 422, and the other side is inserted through the connection hook hole 412a. It is supported and inserted into any one of the pair of power line connection ports 413 by the movement of the transfer block 422 to electrically connect the battery side electric wire L1 and the power distribution wire L3 or the first electric front electric wire ( L2) and a transfer unit 420 having a connection portion 423 made of a conductor material that electrically connects the power distribution line L3; a power line conversion device portion 400 consisting of: a body portion provided with fastening portions 511a on outer circumferential surfaces of both ends 511 and a semi-circular shape formed on both ends of the body portion 511 Of the groove and a plurality of contact protrusions (512a), a body portion 511, body 510 via both ends made of a terminal portion 512 of the metal material which is exposed to the outside of and; A sphere 520 having a fastening hole 521 and inserted into the terminal portion 512 to face the contact protrusion 512a; A semi-circular shape is formed as a whole, but a guide portion 531 and a retaining portion 532 formed by cutting in a cross shape on one side are integrally formed, glass fibers 533 are provided inside, and a fastening portion of the body 510 is provided on the other inner circumferential surface. The fastening portion 534 coupled to the (511a) is integrally formed and is detachably coupled to the body 510 and the cap 530 surrounding the sphere 520; The first and second KEPCO side wires L2 and L2 'are accommodated in the wire receiving portion 541a, the wire fixing portion 550, and the wire fixing portion receiving portion 541b and the wire fixing portion 550, respectively. The connecting body 541 provided with the insertion groove 541c providing a passage and the connecting body 541 are installed to protrude and are coupled to the fastening hole 521 of the sphere 520 and accommodated in the wire receiving portion 541a A first and second KEPCO side wires (L2, L2 ') and a metal material wire connector 540 composed of fasteners 542 that are electrically connected to each; It is formed continuously along the inner circumferential surface longitudinal direction and is fixed to the circumferential surfaces of the first and second KEPCO front wires L2 and L2 ', respectively, and through the insertion / removal groove 541c extending outward from the outer circumferential surface. An electric wire fixing member 550 composed of the shoveling protrusions 552 to be inserted; One end and the other end is installed on the circumferential surface of the body 510 and the wire connector 540 to seal between the body 510 and the wire connector 540; a connecting device 500 consisting of: Includes a control unit 600 that controls the power line converting device 400 when the amount of power remaining in the storage battery 300 is smaller than a set value, and automatically controls the power line converting device 400 when a certain period of time has elapsed. Disclosed is a new and renewable combined cycle power generation system for multi-family houses using solar energy and wind power. However, in the present invention, in the case of 'confirming the remaining power of the storage battery 300 and controlling the power line converting device 400 when it is smaller than a set value, and automatically controlling the power line converting device 400 after a certain period of time', , The power line converter unit 400 is composed of a converter unit main body 410 and a transfer unit 420, in the case of this embodiment is installed in the basement (1 '; see FIG. 1) of the apartment, the control unit 600 Controlled by the operation, the battery side wire L1 and the power distribution line L3 are electrically interconnected so that power from the solar power generation unit 100 and the wind power generation unit 200 is transmitted through the switchboard 1a (see FIG. 1). In the process of being supplied to each household or by electrically interconnecting the first KEPCO (L2) and the power distribution line (L3), the power from the power plant is supplied to each household through the switchboard (see FIG. 1A). Distributed power (solar power generation, wind power generation) and grid Saenggimyeo power is changed to an optional used in the power quality (Korea Electric wire side) there is a problem of being able uniformity may result in a temporary power failure during the lowering and the selection of the type of power comprising time

Registered Patent No. 10-1402340 (Registration Date: May 26, 2014) "Renewable Combined Cycle Power Generation System for Apartment Houses Using Solar Energy and Wind Power"

The object of the present invention is to solve this problem, and in providing electricity generated by solar and wind power in a certain area, the supply of power is insufficient or unstable in a micro grid system that uses natural energy as a distributed power source. It solves the problem and solves the problem that temporary power failure or power quality deterioration may occur when the grid-connected power is detached from the hybrid system that supplies power using distributed power and grid connection to supply or stop electricity. , It is possible to charge an electric vehicle even at home, and to provide an IoT hybrid micro grid system that has the effect of compensating for the inconvenience that it was difficult for a general user who is not an expert to remotely easily monitor and control the hybrid micro grid system.

The object of the present invention is to install a hybrid power generation device that generates electricity from a plurality of distributed power sources such as solar or wind power in a certain area, such as a house or apartment, to generate electricity, store it in an ESS (Energy Storage System), and then In constructing a micro grid system that uses electricity, when the ESS charge or the power generation capacity of the hybrid power generation unit is insufficient, the electricity is supplied to the ESS by connecting to an external system using an uninterruptible power supply (UPS) function. If the user can use electricity and the ESS charge or the power generation of the hybrid generator is sufficient, the connection to the external system is disconnected and power is supplied to a certain area only with electricity produced by the hybrid generator, and the hybrid generator And management of power systems including ESS It can be achieved by the IoT hybrid micro-grid system according to the present invention that can be controlled wirelessly through a user's smartphone or other devices connected to the online in a remote place.

The IoT hybrid micro grid system according to the present invention applies a progressive system in which the electricity bill policy in Korea discriminates and charges the unit price of electricity bills for each usage section according to the total power consumption of each electricity demand. Electricity self-sufficiency greatly reduces electricity bills, and by adopting a hybrid method using both distributed and grid-connected power, the problem of power shortage and quality degradation is solved, and the ESS has a minimum charge holding capacity of a certain level or more. Even when power supply and demand is unstable or power is cut off, power can be used without power outage by using the residual power of ESS and additional electricity production from distributed power. If power outage is expected, the level of the minimum charge holding capacity of ESS can be increased in advance. So that power can be used more stably. In the meantime, technology is being developed to enable the user of the facility to collect, predict and optimize field operation information in an integrated manner in monitoring or controlling the micro grid system, and charging electric vehicles at home. The technology to optimize energy use, respond to changes in power demand, and monitor the status of inverters and ESS in real time can be applied using IoT, and the control of the micro grid system through such IoT is a smart building. It has a very good effect, such as having an application possibility that can be incorporated into an automation system and used.

1 is a conceptual diagram of an IoT hybrid micro grid system according to an embodiment of the present invention
Figure 2 is a connection structure of a hybrid inverter unit of the IoT hybrid micro-grid system according to an embodiment of the present invention
Figure 3 is a block diagram of the hybrid inverter part of Figure 2
4 is a connection diagram showing a connection relationship of an IoT hybrid micro grid system according to a first embodiment of the present invention
5 is a system utilization plan according to an embodiment of the present invention

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the contents described in the drawings, which illustrate preferred embodiments of the present invention.

IoT hybrid micro grid system according to an embodiment of the present invention, as shown in Figure 1, a solar power generation device (1), a wind power generator (2), a hybrid inverter unit and controller (3), ESS (4) , Control server (5), user (6) and power line system (7).

Hereinafter, the present invention will be described in more detail by explaining preferred embodiments of the present invention with reference to FIGS. 1 to 4.

The photovoltaic device 1 is installed at a location close to a user (Customer, 6) of the present invention (mainly a roof of a user's building, etc.), and produces electricity from sunlight using a solar panel, and a hybrid inverter unit and controller It is a device that is connected to (3) and wires to supply electricity to the hybrid inverter unit and controller (3).

In terms of power generation capacity, if the photovoltaic device 1 is composed of 8 solar panels of the 370 W standard, it generates about 11 kW of electricity per day on a sunny day with a standard of 3 kW.

The wind power generator 2 is installed in the form of a pillar at a position close to the user C of the present invention (mainly on the site being used by the user), and produces electricity including a blade and a generator rotated by wind. It is a device that is connected to the hybrid inverter unit and the controller 3 by electric wires to supply electricity to the hybrid inverter unit and the controller 3.

In terms of power generation capacity, if the blades of the wind power generator 2 have a 1 kW standard, an average of about 4.8 kW of electricity is produced per day based on a windy day of about 5 m / s.

The hybrid inverter unit and the controller 3 is composed of a hybrid inverter unit 31 and the controller 32, the hybrid inverter unit and the controller 3 is the solar power generator 1 and the wind generator 2 and the outside Electricity connected to the system 7 for supplying electric power and each wire, and outputting electricity input from the photovoltaic device 1 and the wind power generator 2 to the ESS 4, or receiving power input from the system 7 It will be output to the ESS or the user.

The hybrid inverter unit 31 of the hybrid inverter unit and the controller 3 converts electricity supplied from direct current into alternating current, and the controller 32 of the hybrid inverter unit and the controller 3 includes the system 7 The hybrid inverter unit 31 is connected or short-circuited, and the ESS 4 is connected to the hybrid inverter 31 or short-circuited.

The hybrid inverter unit 31 includes an input filter unit 31a, an AC conversion circuit unit 31b, an internal transformer unit 31c, a switching unit 31d, and an output filter unit 31e, and the hybrid inverter unit unit ( 31) receives the DC power from the photovoltaic device 1 and the wind power generator 2, converts the DC into AC and outputs it.

Specifically, the hybrid inverter unit 31 converts and outputs power input to DC into AC power, and the AC power output from the hybrid inverter unit 31 is the commercial power used in the external power line system 7 It is output in synchronization with the allowable frequency of power.

The input filter unit 31a of the hybrid inverter unit 31 filters noise of incoming DC power, converts it into DC power from which noise is removed, and outputs the noise.

The AC conversion circuit unit 31b converts and outputs the direct current applied from the input filter unit 31a into a high-frequency three-phase power source having a frequency higher than an allowable frequency in the power line system 7.

The internal transformer unit 31c outputs the high-frequency three-phase power applied from the AC conversion circuit unit 31b through three internal transformers divided for each phase.

The switching unit 31d switches the high-frequency three-phase power output from the internal transformer unit 31c so as to be synchronized with the allowable frequency, that is, 60 Hz for each phase, and converts the converted high-frequency three-phase power into a primary three-phase power.

The output filter unit 31e filters the primary three-phase power applied from the switching unit 31d, converts it into a secondary three-phase power source having a sine wave form, and outputs it.

The controller 32 of the hybrid inverter unit and the controller 3 includes a photovoltaic device 1, a wind power generator 2, a hybrid inverter unit 3, a system 7, an ESS 4, and a user 6 ), And control the operation of the hybrid inverter unit 3, the system 7, the ESS 4, the user 6, the internal operation switch 8 and the system switch 9 according to the monitoring result. It performs a function of transmitting and receiving to and from the control server 5.

The controller 32 indicates whether a power outage has occurred in the system 7, whether the power is generated by the solar light emitting device 1 and / or the wind power generator 2, the solar light emitting device 1 and / or wind power When generating power from the generator 2, it is possible to monitor the production amount, monitor the state of charge of the ESS 4, and monitor the amount of power consumed by the user 6, time, and the like.

The internal operation switch 8 and the grid switch 9 are connected in series between the hybrid inverter unit and the controller 3 and the grid 7, and perform on / off operation according to the control of the controller 32 to perform solar power. The current flow between the power generation device 1 and the wind power generator 2 and the system 7 is controlled. For example, when the power of the solar power generator 1 and the wind power generator 2 and / or the ESS 4 is supplied to the user 6, the internal operation switch 8 is turned on and the system switch 9 Operates off.

When the power of the solar power generation device 1 and the wind power generator 2 and / or the ESS 4 is supplied to the system 7 or the power of the system 7 is used by the user 6 and / or the ESS 4 In case of supplying to, the system switch 9 is turned on. As the internal operation switch 8 and the system switch 9, a switching device such as a relay capable of withstanding a large current may be used.

The ESS 4 receives and stores the power of the photovoltaic device 1 and the wind power generator 2 and / or the system 7, and supplies the stored power to the user 6 or the system 7 . The ESS 4 may include a portion that stores power and a portion that controls and protects it.

The connection between the input and the output of the hybrid inverter unit and the controller 3, referring to the bar shown in FIG. 2, operates differently according to the conditions set by the user using the controller 32, but the current photovoltaic device (1) and the amount of electricity produced per hour (W1) supplied by the wind power generator (2), the current user's hourly electricity consumption (W2), the current amount of charge (E) of the ESS (4), and the value set by the user According to the value of the reference value. For example, when the charge amount E of the ESS 4 exceeds a predetermined reference value, the system-user connection (S2) and the system-ESS connection (S3) are blocked and the ESS-user connection (S1) ) Is made, and power is supplied to the user 6 from the ESS 5, and when the charging amount E of the ESS 4 becomes a predetermined reference value T1, for example, 2 kW or less, a system-user connection S2 is made. Power is supplied to the user 6 from the losing system 7, wherein the ESS 4 receives power from the solar power generation device 1 or the wind power generator 2 and the charging amount E of the ESS 4 is When the predetermined reference value T1 is exceeded, the system-user connection S2 is blocked again.

However, depending on the setting by the user 6, when the charging amount E of the ESS 4 is a preset reference value T2 (a value set differently from the above T1), for example, 8 kW or less, the system-ESS It can be set through the controller 32 so that the inter-connection (S3) is made, and the effect of such a setting change is the amount of charge of the ESS in case of a system outage in advance or in case of a sudden system outage due to a lightning strike in the summer. There is an advantage of sufficiently securing (E). However, the disadvantage of the above setting is not only the electric power produced by the photovoltaic device 1 and the wind power generator 2 but also the system 7 while charging the ESS 4 from the reference value T2-T1 section, for example, 2kW to 8kW of charge. ) Is used at the same time, so it is impossible to use the surplus power of the photovoltaic device 1 and the wind power generator 2 produced from the time when the ESS 4 is fully charged, and the power of the system 7 is used. The charge may have been charged in advance, which may lead to an increase in electricity rates. At this time, in the case of the photovoltaic power generation device, power generation is mainly performed during the daytime, so the charging amount E of the ESS 4 is set differently according to the time zone, so that the photovoltaic power generation amount rises immediately before the photovoltaic power generation rises. It will be said that it is also possible to lower the) and increase the reference value (T2) immediately after the amount of solar power generation decreases.

The controller 32 is connected to the hybrid inverter part and the controller 3, and each part of the micro grid system, a solar power generation device 1, a wind power generator 2, a hybrid inverter part and a controller 3, and an ESS 4 It can monitor the operation status and control the operation, and is composed of an external control server (5) and an MCU that is wirelessly connected online.

The controller 32 provides a function of using the power of the system 7 in the form of an uninterruptible power supply (UPS) in an emergency, as described in detail in the description of the hybrid inverter unit and the controller 3, ESS because the electricity production of the photovoltaic device 1 or the wind power generator 2 is interrupted or the hourly electricity production amount W1 supplied from the photovoltaic device and the wind power generator is lower than the electricity consumption per hour (W2) of the user 6 When the charging amount of (4) becomes equal to or lower than a predetermined reference value (T1), the electric power of the system 7 is bypassed to be supplied to the user 6 and from the solar power generation device 1 or the wind power generator 2 When the supply of electricity is resumed, the connection between the system 7 and the user 6 is automatically disconnected.

ESS (4) is connected to the hybrid inverter unit and the controller (3) is charged with electricity generated by the solar inverter (1) or wind power generator (2) is supplied through the hybrid inverter unit and the controller (3) power The stored and stored power can be supplied to the user 6 through the hybrid inverter unit and the controller 3. In addition, as described above, depending on the setting of the user 6, it is possible to charge the ESS 5 with the power of the system 7 through the system-ESS connection S3. The capacity and type of the ESS 4 may be, for example, 11.5 kWh (DC 48V) class lithium-ion battery.

The control server 5 is an online server connected to the controller 32 through a communication network, so that the controller 32 and the user 6 can monitor or operate the controller 32 through a website or app. It supports wireless hybrid grid system to operate as an Internet of Things (IoT) device.

The control server 5 may be a management company (not shown) in which a plurality of users 6 are subscribed to operate it, or a computer (not shown) installed in the home of the user 6.

In addition, by providing an electric vehicle charging system (8) and connecting the hybrid inverter unit and the controller (3) with electric wires to supply electric power to the electric vehicle charging system (8), a solar power generator (1) or a wind generator (2) It is possible to charge the electric vehicle with the power produced by).

As described above, optimal embodiments have been disclosed in the drawings and specifications. Although specific terms have been used herein, they are only used for the purpose of describing the present invention and are not used to limit the meaning or limit the scope of the present invention described in the claims. Therefore, those skilled in the art will understand that various modifications and other equivalent embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

A: IoT hybrid micro grid system
1: Solar power generator 2: Wind power generator
3: Hybrid inverter part and controller
4: ESS 5: Control Server
6: User 7: System
8: Electric vehicle charging system
W1: (current) electricity production per hour supplied by solar power and wind power generators
W2: (current) user's hourly electricity consumption
E: (current) ESS charge
S1: ESS-user connection S2: System-user connection
S3: System-ESS connection

Claims (3)

In the IoT hybrid micro grid system,
The IoT hybrid micro grid system includes a solar power generator 1, a wind power generator 2, a hybrid inverter unit and a controller 3, an ESS 4, a control server 5, a user 6, and a power line system ( 7),
The hybrid inverter unit and the controller 3 is composed of a hybrid inverter unit 31 and the controller 32,
The hybrid inverter unit 31 includes an input filter unit 31a, an AC conversion circuit unit 31b, an internal transformer unit 31c, a switching unit 31d, and an output filter unit 31e.
The controller 32 monitors the state of the photovoltaic device 1, the wind power generator 2, the hybrid inverter 3, the system 7, the ESS 4, and the user 6, and the monitoring result Therefore, it controls the operation of the hybrid inverter (3), the grid (7), the ESS (4), the user (6), the internal operation switch (8) and the grid switch (9) and performs the function of transmitting and receiving with the control server (5) and,
The input filter unit 31a of the hybrid inverter unit 31 filters the noise of the incoming DC power, converts it into DC power from which the noise is removed, and outputs it,
The AC conversion circuit unit 31b converts and outputs the direct current applied from the input filter unit 31a into a high-frequency three-phase power source having a frequency higher than an allowable frequency in the power line system 7,
The internal transformer unit 31c outputs the high-frequency three-phase power applied from the AC conversion circuit unit 31b through three internal transformers divided for each phase,
The switching unit 31d switches the high-frequency three-phase power output from the internal transformer unit 31c to be synchronized with the allowable frequency, that is, 60 Hz for each phase, and converts it to a primary three-phase power, and outputs it.
The output filter unit 31e filters the primary three-phase power applied from the switching unit 31d, converts it into a secondary three-phase power source having a sine wave, and outputs the converted output signal.
The controller 32 is whether or not a power outage has occurred in the system 7, whether the power is generated by the solar light emitting device 1 and / or the wind power generator 2, the solar light emitting device 1 and / or wind power When generating power from the generator 2, it monitors the production amount, monitors the charging state of the ESS 4, monitors the power consumption, time, etc. of the user 6,
The internal operation switch 8 and the grid switch 9 are connected in series between the hybrid inverter unit and the controller 3 and the grid 7, and the internal operation switch 8 and the grid switch 9 have a large current. A relay that can withstand
The ESS 4 receives and stores the power of the photovoltaic device 1 and the wind power generator 2 and / or the system 7, and supplies the stored power to the user 6 or the system 7 . The ESS 4 includes a portion for storing electric power and a portion for controlling and protecting it,
IoT hybrid micro grid system characterized by supplying electric power to the electric vehicle charging system (8) by connecting to the hybrid inverter unit and the controller (3) by wires delete delete

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