KR20200103949A - Smart energy storage system suitable for solar power generation - Google Patents

Abstract

The present invention relates to a smart energy storage system suitable for a low-capacity solar power plant. The smart energy storage system of the present invention is provided as a package structure installed under the structure of a solar power plant. The smart energy storage system includes an air conditioning device that minimizes power consumption in the site inside a package structure made of a urethane panel that is not affected by the external environment. The smart energy storage system may variably control the state of charge of the battery to maximize the efficiency of the battery and energy storage system, as well as a pre-risk detection function. According to the present invention, it is appropriately implemented for a low-capacity solar power plant, can be applied to an existing solar power plant, and guarantees a stable power generation income to an operator of a solar power plant through efficient energy management and stable business feasibility.

Description

Smart energy storage system suitable for low-capacity solar power plants{SMART ENERGY STORAGE SYSTEM SUITABLE FOR SOLAR POWER GENERATION}

The present invention relates to an energy storage system, and more specifically, provided with an air conditioning system that is installed under the structure of a solar power plant to minimize power consumption in the site, and is an insulating structure that is independent of external environmental influences for efficient air conditioning and battery operation. It is possible, and it is possible to detect risk in advance such as fire, it is possible to variably adjust the state of charge (SOC) of the battery to maximize the efficiency of the battery, implement the EMS algorithm in consideration of the SMP price of the power exchange, and cloud-based It relates to a smart energy storage system suitable for a low-capacity solar power plant that can be managed in an integrated manner.

In general, there is a smart grid as a future power grid that optimizes the operational efficiency of the power grid through two-way communication between suppliers and consumers while observing and controlling the power grid in real time by grafting information and communication technology to the existing power system. This enables connection with new power devices such as new and renewable energy generation and charging systems for electric vehicles, which are increasing in recent years, and increases power use efficiency by providing power usage information of consumers in real time. It can be expected to reduce greenhouse gas emissions.

With the development of the industry, power demand is gradually increasing, and the gap in power usage between day and night, seasons, and daily is gradually widening. Recently, for this reason, many technologies to reduce the peak load by utilizing the excess power of the system are being developed rapidly, and a representative of these technologies is energy that stores the excess power of the system in the battery or supplies the insufficient power of the system from the battery. It is an Energy Storage System (ESS).

The energy storage system (ESS) stores surplus power at night or power generated from renewable energy sources such as solar and wind power, and supplies the power stored in the battery to the system in case of a peak load or a system accident. Through this, it is possible to stabilize system power that fluctuates unstable by renewable energy sources, and achieve maximum load reduction and load leveling.

Such an energy storage system includes, for example, a battery module composed of a lithium-ion battery having a high energy storage density, and the battery modules are electrically connected to each other in a predetermined number to be stacked in a multi-stage battery rack. When storing the battery modules, such a battery rack must maintain a constant temperature and humidity, be well ventilated, and facilitate maintenance of the loaded battery modules.

However, when the state of charge (SOC) of the battery modules is different from each other, when charging or discharging the battery rack, some battery modules may be charged or discharged first depending on the energy state of the battery module. There is a problem that they cannot be fully charged or completely discharged.

In particular, it is difficult to install ESS in low-capacity solar power plants of less than 100 Kw, which accounts for about 90% of the country. For example, since standardized containers and battery racks with a height of about 1,800 mm are used, there is not enough space for installing energy storage systems in small-capacity solar power plants currently in operation. In addition, as a commercial air conditioning system is used for the energy storage system, air conditioning efficiency is very low and power consumption is high. In addition, since the energy storage system is manufactured in a container or sandwich panel method, power consumption in the site increases due to low insulation, and ESS efficiency decreases. In addition, since only EMS monitoring is possible, it is difficult to detect abnormal signs such as fire in advance.

Korean Patent Application Publication No. 10-2018-0120500 (published on November 06, 2018) Korean Patent Publication No. 10-1732436 (announced on May 04, 2017) Korean Registered Patent Publication No. 10-1597993 (announced on February 29, 2016) Korean Patent Registration No. 10-1493355 (announced on February 13, 2015)

An object of the present invention is to provide a smart energy storage system suitable for a low-capacity solar power plant that is provided as a package structure and can be installed in an existing solar power plant.

Another object of the present invention is to provide a smart energy storage system suitable for a low-capacity solar power plant having an air conditioning system that enables efficient air conditioning and battery operation and minimizes power consumption in a site by being provided with an insulating structure irrelevant to external environmental influences. .

Another object of the present invention is to provide a smart energy storage system suitable for a low-capacity solar power plant that detects the occurrence of a risk in advance such as a fire.

Another object of the present invention is to provide a smart energy storage system suitable for a low-capacity solar power plant that variably adjusts a battery charge state to maximize battery efficiency.

In order to achieve the above objects, the smart energy storage system suitable for the low-capacity solar power plant of the present invention is formed of a urethane panel of a certain thickness and provided as a package structure installed under the structure of the solar power plant. Such a smart energy storage system may be suitably installed in a low-capacity solar power plant by accommodating at least one battery rack, a connection panel, and at least one inverter provided in the form of a module independent of the package structure.

The smart energy storage system suitable for the low-capacity solar power plant of the present invention according to this feature includes: a battery rack having a plurality of battery modules for storing electric power generated by converting from solar light to electric energy from a plurality of solar modules; A connection panel for collecting DC power produced from the solar module; An inverter converting DC power collected from the connection panel into AC power and transmitting power to charge the battery module; And charging the battery module by receiving the power produced by the solar module, or transmitting the power charged in the battery module to the power grid or load when a peak load or an emergency situation occurs in the power grid system to supply power to the system. And an energy management device for real-time monitoring of power produced by the solar module or power charged and discharged from the battery module; The smart energy storage system includes at least one battery rack, the connection panel, and at least one inverter provided in the form of independent modules in a package housing installed under the solar power plant structure so that they are electrically connected to each other. It is accommodated in, and the air conditioning device is provided on the inner upper end of the package housing.

In this feature, the package housing is provided with a urethane panel made of aluminum having a predetermined thickness; The lower part of the package housing is formed of an H beam to support the smart energy storage system, and the upper part is provided with a double insulation structure.

In this aspect, the package housing is provided with a plurality of temperature sensors for measuring temperatures at different locations inside the package housing so as to monitor the temperature inside the package in real time.

In this aspect, the energy management device; The voltage, current, and temperature according to the charging and discharging of the battery module are measured, and the battery charge state of the battery module is variably adjusted by estimating the battery capacity according to the measured voltage, current, and temperature.

In this aspect, the energy management device; The solar module and the voltage, current, and temperature according to the operating state of the smart energy storage system are monitored in real time, and the normal and error states of each device of the solar module and the smart energy storage device are monitored in real time, and an abnormality occurs. At the time, it notifies to the outside whether or not the device is abnormal.

As described above, the smart energy storage system of the present invention is provided as a package structure and is installed under the structure of a solar power plant that lacks existing installation space, so that an energy storage system suitable for a low-capacity solar power plant can be implemented.

In addition, the smart energy storage system of the present invention is provided as a package structure suitable for low-capacity solar power plants, so as to develop an insulating structure that maximizes system efficiency due to external environmental influences, develop an air conditioning system to minimize power consumption in the site, and risk Profitability models of solar power plants and energy storage systems can be implemented by providing detection function development, optimal battery state of charge (SOC) implementation, and EMS algorithm implementation considering SMP.

In addition, the smart energy storage system of the present invention provides a remote clear function and transmission of abnormalities by comprehensively considering the occurrence of voltage, current, temperature, system status, and weather conditions as well as the presence or absence of each device. Can prevent the occurrence of emergency situations.

In addition, the smart energy storage system of the present invention enables the use of an independent power source of the micro grid concept in case of an emergency, secures system stabilization by supplementing the disadvantages of solar power generation that can generate electricity only during the day, and secures a new renewable energy supply certificate. , Since it is possible to implement a system that generates additional profits according to the application of Renewable Energy Certificates (REC) 5.0, it is possible to obtain an expansion of the marketability of the energy storage system 100.

1 is a block diagram showing the configuration of a smart energy storage system suitable for a low-capacity solar power plant according to the present invention,
2 is a view showing the installation state of the smart energy storage system shown in FIG. 1;
3 is a diagram showing the configuration of the smart energy storage system shown in FIG. 2, and
4 is a flowchart showing a processing procedure for variable SOC adjustment of the smart energy storage system according to the present invention.

The embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. This embodiment is provided to more completely explain the present invention to those of ordinary skill in the art. Therefore, the shape of the constituent elements in the drawings is exaggerated in order to emphasize a more clear description.

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

1 is a block diagram showing the configuration of a smart energy storage system suitable for a low-capacity solar power plant according to the present invention.

Referring to Figure 1, the smart energy storage system 100 of the present invention, for example, in order to be suitable for a low-capacity solar power plant of 100 Kw or less, development of an insulating structure that maximizes system efficiency due to external environmental influences, power in the site Profitability model of solar power plant and energy storage system by providing air conditioning system development to minimize consumption, development of pre-risk detection function, implementation of optimal battery state of charge (SOC) and implementation of EMS algorithm considering System Marginal Price (SMP) Implement

In the case of an emergency, the smart energy storage system 100 enables the use of independent power of the micro grid concept and secures system stabilization by supplementing the shortcomings of photovoltaic power generation that can generate electricity only during the daytime, and a new renewable energy supply certificate, for example , Since it is possible to implement a system that generates additional profits according to the application of Renewable Energy Certificates (REC) 5.0, it is possible to obtain an expansion of the marketability of the energy storage system 100.

In addition, the smart energy storage system 100 provides an abnormality transmission and remote clear function in consideration of not only the presence or absence of an abnormality of each device, but also the voltage, current, temperature, system state, and weather conditions that occur.

To this end, the smart energy storage system 100 of the present invention includes a battery, a PCS, an air conditioning device, a firefighting device, and an EMS, etc., in order to efficiently store and manage power according to photovoltaic power generation from the photovoltaic generator 200. Design and manufacture an ESS package (100 in FIG. 3).

That is, the solar power generation system 2 of the present invention includes a smart energy storage system 100, a solar generator 200, a switchboard 300, and a control server 400. In addition, the photovoltaic power generation system 2 is connected to a plurality of energy storage systems 100 and a control server 400 through a communication network 4.

The photovoltaic generator 200 includes a plurality of photovoltaic modules 210, a connection panel 220 and an inverter 230. The solar generator 200 is fixedly installed on the solar power plant structure (240 in FIG. 2).

The photovoltaic module 210 is a photovoltaic power generation (PotoVltaics: PV) module, and a plurality of photovoltaic modules 210 are provided to convert sunlight into electrical energy to produce power. The solar module 210 stores the generated power in the battery module 110 or supplies power to a load.

The connection panel 220 is located between the photovoltaic module 210 and the inverter 230, and connects direct current power produced by the photovoltaic module 210 in series and parallel to collect necessary power. The connection panel 220 supplies DC power produced by the solar module 210 to the inverter 230.

The connection panel 220 collects DC power produced by the solar module 210 and transmits it to the inverter 230 in order to prevent the inverter 230 from failing. This prevents a collision between the photovoltaic modules 210 that may occur depending on the amount of power of the photovoltaic module 210, prevents electric backflow between the photovoltaic module 210 and the inverter 230, and prevents short circuits or overcurrent. Block it. To this end, the connection panel 220 is provided with a reverse current prevention module, a voltage current detection module, a communication module, an SPD heat dissipation pad, a circuit breaker, etc. to detect and monitor DC voltage, current, temperature, reverse current, etc., and overcurrent, reverse current. And a function of protecting against power spikes using a lightning protection device (SPD). In addition, the connection panel 220 is provided with a smoke sensor and a fire detection sensor to detect the occurrence of an emergency situation, and a waterproof and dustproof function.

The inverter 230 converts DC power supplied from the connection panel 220 into AC power and transmits the power to charge the battery 110 through the switchgear 300 or to a load through the power grid.

In the solar generator 200, an energy storage system 100 is disposed on a lower side of the solar power plant structure (210, 240 in FIG. 2).

The switchboard 300 transmits power other than the power required to charge the battery 110 of the energy storage system 100 to the power grid. The switchboard 300 is provided with a transformer, a meter, etc. to transmit power generated from a solar module through a power grid or to charge the battery 110. The switchboard 300 transmits power charged from the battery through a power grid.

The control server 400 is provided, for example, in an energy integrated control center, and is connected to the energy management device 150 through a communication network 4 to integrate and manage a plurality of energy storage systems 100 on a cloud basis. When an event occurs in the solar power plant, the control server 400 monitors the event situation by receiving event-related information from the energy management device 150, and remotely to the energy management device 150 when the event can be resolved remotely. It transmits a control signal, and if it can be resolved on site, it transmits notification information to the operator (or business owner) or manager of the solar power plant using a text message.

The energy storage system 100 charges the battery module 110 by receiving power produced by the solar module 210, or when a peak load or an emergency situation occurs in the power grid system, the power charged in the battery module 110 is It performs the function of supplying power to the system by transmitting to the power grid or load.

To this end, the energy storage system 100 is designed in a package structure having a size that can be installed in most solar power plants currently in operation, and has an optimized air conditioning device for reducing power in the site and increasing the efficiency to keep the temperature inside the package constant. In order to minimize the occurrence of emergency situations such as fire by detecting danger in advance, and to minimize the occurrence of emergency situations such as fire by maximizing ESS operation efficiency and considering economical efficiency, air circulation is overall To achieve uniformity, for example, a double-structured roof (Fig. 2A) is provided using a 100t aluminum urethane panel for minimum thermal conductivity and corrosion prevention, and an air conditioning device (not shown) at the top of the interior. Installed). This ESS package has a thermal conductivity of about 50% lower than that of existing styrofoam or glass fiber, and is equipped with a high-efficiency air conditioner based on heat flow analysis, thereby reducing power consumption by about 30% compared to the previous one. can do. In addition, the energy storage system 100 detects the presence or absence of abnormalities such as the battery module 110, PCS 120, and BMS 130 inside the package in advance, SOC management according to the EMS optimization logic, and smart It provides ESS (100) and EMS (150).

Specifically, the energy storage system 100 includes a battery rack including a plurality of battery modules 110, a power conversion device 120, a battery management device 130, a power management device 140, and an energy management device 150. Include. The energy management device 150 is connected to the control server 400 of the integrated energy control center through the communication network 4.

The battery module 110 stores power generated from the solar module 210. A plurality of battery modules 110 are stacked to be electrically connected and accommodated in a battery rack. The battery rack is electrically connected to and independently provided with the package module (102 in FIG. 3) of the energy storage system 100.

When power is stored or used by the battery module 110, the power conversion device (Power Conditioning System: PCS) 120 converts the characteristics of electricity from AC to DC or DC to AC.

The battery management system (BMS) 130 stores the power supplied from the photovoltaic module 210 in one or more battery racks, and is stored in one or more battery racks in the event of a system accident such as a peak load or power failure. Supply the existing power to the power grid.

The power management system (PMS) 140 connects the battery management device 130 and the power conversion device 120 to transmit power to the power grid. That is, the power management device 140 charges one or more battery racks by the battery management device 130 or discharges power stored in one or more battery racks.

In addition, the energy management system (EMS) 150 controls and monitors all operations of the energy storage system 100. The energy management device 150 monitors the charging/discharging history of system power in real time, such as power produced by the solar module 210 or power charged and discharged from the battery module 110. The energy management device 150 monitors battery charging/discharging efficiency, power generation time, solar power generation information, and the like in real time. The energy management device 150 monitors voltage, current, temperature, etc. according to the operating state of the photovoltaic module 210, PCS 120, and BMS 130 in real time, and monitors normal and fault conditions for each device in real time. And, when an error occurs, it informs the outside by displaying the presence or absence of the device.

In addition, the energy management device 150 is connected to the power management device 140 and the switchboard 300 to measure and monitor the power transmitted to the power grid among the power produced from the solar module 210 in real time, or the battery module 110 It measures and monitors the power transmitted to the power grid in real time among the power stored from

In addition, the energy management device 150 is interlocked with the energy storage system 100 to detect the occurrence of a danger in advance to prevent the occurrence of an emergency situation such as a fire in the energy storage system 100, and the BMS of the battery module 110 Whether there is an abnormality in the voltage and current values identified by 130, whether there is an abnormality according to the amount of power produced by the inverter 230, whether the temperature of the battery rack is increased, an abnormality in the charging/discharging temperature and current values of the battery module 110 When an error occurs by defining events such as presence or absence, the operation by the sensor is stopped through remote control, and EMS warning and automatic message transmission functions are provided.

In addition, the energy management device 150 performs functions such as controlling the operation schedule of the energy storage system 100, reporting various data of the energy storage system 100, power management of the energy storage system 100, and predicting system demand or generation amount. Perform. In addition, the energy management device 150 performs functions such as managing power transaction history and establishing an optimal power generation plan.

In addition, the energy management device 150 manages power storage and supply by calculating an optimized state of charge (SOC) based on data analysis with PCS, BMS, and inverter.

Specifically, a description of the configuration and function of the smart energy storage system according to the present invention will be described in detail with reference to FIGS. 2 to 4.

FIG. 2 is a diagram illustrating an installation state of the smart energy storage system illustrated in FIG. 1, and FIG. 3 is a diagram illustrating the configuration of the smart energy storage system illustrated in FIG. 2.

2 and 3, in the smart energy storage system 100 of the present invention, a solar module 210 is fixedly installed on an upper portion of the solar power plant structure 240, and the lower portion of the solar power plant structure 240 An energy storage system 100, that is, an ESS package, is installed on one side.

The energy storage system 100 has a double-structured roof (A) using a 100t-thick aluminum urethane panel for minimum thermal conductivity and corrosion prevention, and an air conditioning device (not shown) at the top of the interior. It has a package housing 102 to be installed.

In this embodiment, the package housing 102 is designed to have a height of up to 2 m and is provided so as to be installed in most solar power plant structures currently in operation. In addition, the package housing 102 is provided to support the package structure using an H-beam at the bottom to withstand the weight of the battery module 110 and the battery rack. In addition, the air conditioner installed on the top inside the package housing 102 is designed to rotate the air by inhaling hot air from the top and releasing cold air from the center and duct, so that the optimum temperature for battery charging and discharging, such as 25°C±5°C It is possible to implement an air conditioning system that can maintain. In addition, a plurality of temperature sensors for measuring temperatures at different locations, such as a lower end and an upper end, are installed inside the package housing 102 so that the temperature inside the package can be monitored in real time.

In addition, the energy storage system 100 is formed in a package structure, and is provided in the form of a module in which each of the at least one inverter module 230, the connection panel module 220, and the at least one battery module 110 is separated and combined. , It is provided to be expandable according to the power generation capacity and battery storage capacity of the solar power plant. In this embodiment, the energy storage system 100 is shown to be composed of two inverter modules 230, one connection panel module 220 and two battery modules 110. This is a situation where about 90% or more of the currently operating solar power plants are less than or equal to 100 Kw, and there is insufficient or no space for the installation of the energy storage system 100. It is provided in a package structure so that it can be installed in size.

This energy storage system 100 prevents an increase in power consumption in the site due to an increase in the operating time of the air conditioner due to insufficient insulation in the conventional container-type energy storage system by applying a urethane panel having a low heat transfer rate of 100 tons. do. For example, under W/mk@20℃, the heat transfer rate of glass wool is 0.037, and the heat transfer rate of urethane is 0.024. In addition, the upper end of the package housing 102 is provided with a double structure of urethane or a triple structure (urethane, air layer, urethane) including an air layer to further improve insulation efficiency.

And Figure 4 is a flow chart showing a processing procedure for variable SOC adjustment of the smart energy storage system according to the present invention. This procedure is handled by the energy management device (EMS) 150 of the energy storage system 100.

Referring to FIG. 4, the smart energy storage system 100 of the present invention measures voltage, current, and temperature according to charge/discharge of each of the battery modules 110 in step S500.

In step S502, the battery capacity C of each battery module 110 is estimated according to the measured voltage, current, and temperature of each of the battery modules 110.

In step S504, it is determined whether the specific battery module 110 is in a load state. As a result of the determination, if the specific battery module 110 is in the load state, the process proceeds to step S506, and a correction value according to the battery capacity C is added to the battery charge state (SOC) value of the previous battery module 110, and the specific battery module ( 110) of the battery state of charge (SOC) value is calculated. However, as a result of the determination, if the specific battery module 110 is not in a load state, the process proceeds to step S508 and the battery charge state (SOC) value of the current specific battery module 110 corresponding to the SOC-OCV (Open Circuit Voltage) curve function Yields

In general, control for the battery state of charge (SOC) is charged or discharged according to the SOC specified in the PMS. Generally, the SOC range is about 3% to 95% or less, and SOC management affects battery life and battery efficiency. For example, if the SOC falls to 1% according to the PMS, since the SOC 1% charge corresponds to one cycle of the battery, the battery efficiency decreases, which is fatal to the battery life.

On the other hand, in the present invention, since the SOC can be variably controlled to adjust the SOC according to the generation prediction, accurate voltage control is possible during charging and discharging.

Therefore, the energy storage system 100 variably controls the battery state of charge (SOC) so that it can be performed within an appropriate range with accurate voltage control during charging and discharging according to, for example, weather, expected charging amount, and line conditions, not simply a proportional charging/discharging algorithm. By variably adjusting the SOC value of the battery module 110, it is possible to prevent a phenomenon in which battery charging/discharging efficiency is lowered.

In the above, the configuration and operation of a smart energy storage system suitable for a low-capacity solar power plant according to the present invention has been illustrated according to the detailed description and drawings, but this is only described by way of example, and does not depart from the technical idea of the present invention. Various changes and changes are possible within the range.

100: smart energy storage system
102: package housing
110: battery module
120: power conversion device (PCS)
130: battery management device (BMS)
140: power management device (PMS)
150: energy management device (EMS)
200: solar generator
210: solar module
220: connection panel
230: inverter
240: solar power plant structure
300: switchboard
400: control server

Claims (5)

In the smart energy storage system:
A battery rack including a plurality of battery modules for storing power generated by converting sunlight into electric energy from a plurality of solar modules;
A connection panel for collecting DC power produced from the solar module;
An inverter converting DC power collected from the connection panel into AC power and transmitting power to charge the battery module; And
The battery module is charged by receiving the power produced by the solar module, or when a peak load or an emergency situation occurs in the power grid system, the power charged in the battery module is transmitted to the power grid or load to supply power to the system. And an energy management device for real-time monitoring of power produced by the solar module or power charged and discharged from the battery module;
The smart energy storage system is provided in the package housing installed under the structure of the solar power plant in the form of an independent module, so that the at least one battery rack, the connection panel, and at least one inverter are electrically connected to each other. Smart energy storage system, characterized in that the air conditioning device is accommodated in the package housing is provided on the top inside.
The method according to claim 1,
The package housing is provided with a urethane panel made of aluminum having a predetermined thickness;
A lower portion of the package housing is formed of an H beam to support the smart energy storage system, the upper portion of the smart energy storage system, characterized in that provided with a double insulation structure.
The method according to claim 2,
The package housing is a smart energy storage system, characterized in that a plurality of temperature sensors are installed to measure the temperature at different locations inside the package so as to monitor the internal temperature in real time.
The method according to claim 1,
The energy management device;
To variably adjust the state of charge (SOC) of the battery module by measuring the voltage, current, and temperature according to the charging and discharging of the battery module, and estimating the battery capacity according to the measured voltage, current, and temperature. Smart energy storage system characterized by.
The method of claim 4,
The energy management device;
The solar module and the voltage, current, and temperature according to the operation state of the smart energy storage system are monitored in real time, the normal and error states of each device of the solar module and the smart energy storage device are monitored in real time, and an abnormality occurs. City, smart energy storage system, characterized in that notifying to the outside the presence or absence of abnormalities in the device.

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