KR20230090461A - The control method of distributed power system for the same time multi-service and apparatus thereof - Google Patents

Abstract

The present invention relates to an apparatus in which a system composed of a renewable energy source or an energy storage system is connected to a power system to provide service to the power system, and more particularly, distributed power sources composed of renewable energy sources are connected to the power system The present invention relates to a device and method capable of simultaneously providing various services for improving power quality or stabilizing a power system when power quality is reduced or a power system is unstable.

Description

The control method of distributed power system for the same time multi-service and apparatus thereof}

This embodiment relates to a device that contributes to improving the stability of the power system by connecting distributed power sources composed of renewable energy and energy storage systems to the power system. It is about a device that can provide

Compared to other power generation methods, the thermal power generation method that converts thermal energy obtained by burning fossil fuels into mechanical energy and obtains electrical energy using mechanical energy does not have difficult location conditions for power generation facilities, has low construction cost, and shortens the construction period. It is short and has the advantage of being able to respond quickly to fluctuations in electricity demand, so it occupied an overwhelmingly higher rate than other power generation methods in the past. However, thermal power generation pollutes the atmosphere while burning fossil fuels and emits greenhouse gases, causing global warming and climate change. As a result, policies are being implemented to gradually reduce the proportion of thermal power generation and increase the proportion of new and renewable energy generation. Accordingly, research related to new and renewable energy is accelerating, and the proportion of new and renewable energy sources connected to the power system is increasing.

Since new and renewable energy sources obtain electrical energy from the natural environment, the amount of power generated by new and renewable energy sources is inevitably affected by changes in the natural environment such as climate. Therefore, new and renewable energy sources inevitably have uncertainty about the production of electrical energy. In the existing power system, power production and consumption are performed simultaneously without the concept of storing electrical energy, so it is very important to maintain power quality and operate the power system to adjust power generation amount in real time according to power consumption. As new and renewable energy sources having uncertainty in power generation are connected to the existing power system, power quality is reduced and the power system becomes unstable. Specifically, fluctuations in the supply and demand of active power due to the uncertainty of electric energy production of new and renewable energy sources cause frequency fluctuations in the power system, and the imbalance between supply and demand of reactive power causes voltage fluctuations in the power system.

Meanwhile, the power system was built based on alternating current. Existing power generation methods, including thermal power generation methods, can produce alternating current directly with an alternator, but new and renewable energy sources produce either direct current or alternating current. In order to supply electrical energy by connecting a renewable energy source that produces direct current, such as photovoltaic power generation, to a power system, an inverter that converts direct current into alternating current is essential. The inverter uses a power semiconductor device in the process of converting direct current into alternating current, and the power semiconductor device can be controlled to adjust the voltage at a grid connection point, which is a point where the inverter and the power system are connected. In the past, the IEEE1547-2003 regulation of the Institute of Electrical and Electronics Engineers of the United States prohibited voltage regulation at grid connection points when distributed power sources were connected to the power system. It is allowed through the IEEE1547-2018 regulation to actively support voltage at the connection point. Through this, new and renewable energy sources that made the existing power system unstable can contribute to improving the stability of the power system.

Inverters that can support various grids for reliability and stable operation at the grid connection point are called 'smart inverters' or 'advanced inverters'. These smart inverters directly control voltage, active power, reactive power, and frequency or control them by receiving commands from the power system in conjunction with a higher management system. can In manual operation, the smart inverter controls the output of the smart inverter according to the instructions of the upper system or the set value of the smart inverter. In autonomous operation, when operating parameters are provided to the smart inverter, the smart inverter determines the output to support the grid by itself using the data measured at the control reference point. Linked driving is similar to autonomous driving, but operates by transmitting data that serves as an operating standard from the upper system to the smart inverter. Currently, research on smart inverters is actively being conducted, standardization of related regulations is in progress, and test methods and standards are being specified.

The patent “Application No. 10-2020-0024514, method and device for classifying and controlling transactional resources for controlling variability of power generation sources”, filed in the Republic of Korea on February 27, 2020 and published on September 6, 2021, is applied to a number of distributed power sources. classifies transaction resources based on a plurality of transaction criteria and distributes the market participation rate;

Against this background, the purpose of this embodiment is that when a new and renewable energy source is connected to the power system to reduce power quality or make the power system unstable, the distributed power supply device and system receive commands from upper systems such as power system operators, It is to provide a service that contributes to improving the quality of the power system or stabilizing the power system by self-determination.

In another aspect, an object of the present embodiment is to implement a set control strategy when there are several services that can contribute to improving the power quality of the power system or stabilizing the power system, and the distributed power device and system can provide multiple services. As a standard, it is to provide a technology that can simultaneously provide multiple optimal services to the power system.

In order to achieve the above object, one embodiment is composed of renewable energy or energy storage system distributed power source 110 capable of generating or storing electrical energy; An electrical device 120 connected to the distributed power source 110 and the power system to supply electrical energy from the distributed power source 110 to the power system or to supply electrical energy from the power system to the distributed power source 110; A first measurement unit 130 connected to the distributed power supply 110 to obtain first time-series data for the measured value of the distributed power supply 110; A second measurement unit connected to a grid connection point, which is a connection point between the electric device 120 and the power system, to obtain second time-series data for a measured value of the grid connection point; A third measuring unit 150 connected to the control unit 170 to obtain third time-series data for values at which the control unit 170 controls the electric device 120; A communication unit 160 that exchanges information with a higher level system or other distributed power supply and system; a control unit 170 controlling the electric device 120 based on the first time series data, the second time series data, the third time series data, and information received from the communication unit 160; It provides a distributed power supply device and system for providing simultaneous multiple services including.

The electric device 120 converts the alternating current of the distributed power source 110 into the alternating current of the power system or converts the direct current of the distributed power source 110 into the alternating current of the power system, while the electric device 120 and the power system A function to adjust electrical characteristics such as voltage and frequency of the grid connection point, which is the connection point of the grid; may further include.

The first measuring unit 130 is connected to the distributed power supply 110 and converts information about the distributed power supply 110, such as voltage, current, and temperature, into a digital signal to obtain the first time-series data (Analog ADC). -Digital-Converter) or DAQ (Data Acquisition); may further include. Hereinafter, an embodiment of the ADC is mainly described, but the ADC may be replaced by DAQ.

The second measurement unit 140 includes an ADC (Analog-Digital-Converter) that is connected to the power system and converts information about the grid connection point, such as voltage, current, and frequency, into a digital signal to obtain the second time-series data; may further include.

The third measuring unit 150 is connected between the control unit 170 and the electrical device 120 to measure the electrical device 120, such as a real power control signal, a reactive power control signal, or a PWM (Pulse Width Modulation) control signal. an ADC (Analog-Digital-Converter) for obtaining the third time-series data by converting information about an output signal of the control unit 170 into a digital signal; may further include.

The communication unit 160 receives the distributed power supply and system operation command from the upper system; receiving power price information from an upper system so that the distributed power supply and system can trade power; Function to receive information on the state of the power system from the upper system; may further include.

The communication unit 160 has a function of exchanging information with a plurality of distributed power devices and systems so that a plurality of distributed power devices and systems can gather and operate as one giant virtual distributed power device and system; may further include.

The controller 170 includes a control method setting unit for setting services provided to the power system; a control strategy setting unit that sets standards for service priorities provided to the power system; Power system based on the first time series data obtained by the first measurement unit, the second time series data obtained by the second measurement unit, the third time series data obtained by the third measurement unit and the information provided by the communication unit a calculation unit that calculates a service provided to; an output unit connected to the electric device and outputting a control signal for controlling the electric device; may further include.

The control method setting unit controls reactive power and active power at a grid connection point where the power system and the electrical device are connected, controls the power factor of the electrical device, limits the maximum power of the electrical device, or supplies energy to the distributed power source. Setting a control method for the electric device, such as controlling charging and discharging of the distributed power source when the storage system is included; may further include. Here, the control method setting unit may directly control or indirectly control the inactive power. The control method setting unit may indirectly control the power factor and perform Volt-Var control by indirect control.

The control strategy setting unit selects the control methods set by the control method setting unit, such as compliance with commands received from the power system, pursuit of maximum profit in the power market, suppression of distributed power aging, suppression of aging of electric devices, and minimization of fluctuations in the power system. Ability to set criteria and priorities; may further include.

In another embodiment, in a method for providing simultaneous multiple services by a distributed power supply device and system, control methods for controlling the electric device connected to the distributed power supply are set so that the electric device can provide service to the power system, and the A setting step of setting a control strategy that is a standard in selecting and selecting one or more control methods from among the control methods; a measurement step of obtaining information necessary for calculation in order to calculate a control signal for controlling the electric device; Based on the information measured in the measuring step, among the control methods set in the setting step, a control method is selected and selected based on the control strategy set in the setting step, and a control signal for controlling the electric device is calculated. step; a control step of controlling the electric device with the calculated control signal; It provides a simultaneous multi-service providing method including.

The setting step is a control method setting step of setting a control method for controlling the electric device, such as active power, reactive power, power factor control, and charge/discharge control of the distributed power supply at a grid connection point that is a connection point between the electric device and the power system. ; The criteria for selecting and selecting the control method set in the control method setting step, such as compliance with commands received from the power system, pursuit of maximum profit in the power market, suppression of aging of distributed power sources, suppression of aging of electrical devices, and minimization of fluctuations in the power system, etc. Control strategy setting step to set; may further include.

The measuring step may include acquiring information about the distributed power supply, such as voltage, current, and temperature of the distributed power supply, as first time-series data; obtaining information about a grid connection point, such as voltage, current, and frequency, as second time series data; Obtaining a control signal transmitted from the controller to the electric device, such as an active power control signal, a reactive power control signal, or a PWM (Pulse Width Modulation) control signal, as third time series data; Obtaining information through communication with a higher level system or other distributed power supply and system; may further include.

The measuring step may include ADCs (Analog-Digital-Converters) for acquiring the first time-series data, the second time-series data, and the third time-series data; may further include.

The calculation step selects and selects one or more control methods based on the information obtained through communication, the first time series data, the second time series data, and the third time series data and based on the control strategy, and the electric device Calculating a control signal for controlling the; may further include.

As described above, according to the present embodiment, the distributed power supply device and system can contribute to improving the power quality of the power system or stabilizing the power system. In addition, according to the present embodiment, it is possible to simultaneously provide multiple services that can contribute to improving the power quality of the power system or stabilizing the power system according to the state of the distributed power supply device and system according to the set control strategy.

1 is a configuration diagram of a distributed power supply device and system for providing simultaneous multiple services according to an embodiment.
2 is a configuration diagram of a distributed power supply device and a system control unit for simultaneous multi-service provision according to an embodiment.
3 is a flowchart of a method for providing simultaneous multiple services of a distributed power supply and system according to an embodiment.
4 is an example of a control method that can be set in a control method setting unit according to an embodiment.
5 is an example of a control strategy that can be set by a control strategy setting unit according to an embodiment.
6 is a configuration diagram of a distributed power supply device and system for providing simultaneous multiple services composed of two according to an embodiment.
7 is a voltage-reactive power (Volt-Var) control curve at a grid connection point.
8 is a voltage-active power (Volt-Watt) control curve at a grid connection point.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, order, or order of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is directly connected or connectable to the other element, but there is another element between the elements. It will be understood that elements may be “connected”, “coupled” or “connected”.

1 is a configuration diagram of a distributed power supply device and system for providing simultaneous multiple services according to an embodiment.

Referring to FIG. 1, a distributed power supply device and system for providing simultaneous multiple services include a distributed power supply 110, an electric device 120, a first measurement unit 130, a second measurement unit 140, and a third measurement unit. 150, a communication unit 160, and a control unit 170.

The distributed power source 110, unlike large-scale centralized power generation facilities such as thermal power generation, is a power generation facility that is disposed near an area with power consumption or in an area where new and renewable energy sources are easy to obtain and supplies power to the existing power system. It may include power generation facilities using renewable energy sources such as furnace, solar power, wind power, and fuel cells.

The distributed power source 110 may include an energy storage system (ESS) that is connected to the power system to receive and store electrical energy from the power system or to supply the stored electrical energy to the power system.

The distributed power source 110 includes a new and renewable energy source, a power converter, and an energy storage system, and supplies electrical energy produced by new and renewable energy sources to the power system or supplies electrical energy stored in the energy storage system to the power system. The electrical energy of the power system can be stored in the energy storage system. As an example, the distributed power source 110 consists of a photovoltaic module coupled with a solar cell, a power converter for converting direct current to direct current to store electrical energy produced by the photovoltaic module in an energy storage system, and an energy storage system. Therefore, when the price of power is high in the power system, the electrical energy produced by the photovoltaic module or the electrical energy stored in the energy storage system can be supplied to the power system through the electrical device 120. In addition, when the energy storage system is not fully charged and the power price is low in the power system, the energy storage system can be charged by receiving electrical energy from the power system through the electric device 120 .

The electrical device 120 may include a switch and convert power by chopping power using the switch. For example, the electrical device may be a two-phase or three-phase inverter or the like. The electric device 120 may have a constant control frequency or a control frequency within a certain range. Here, the control frequency may determine a cycle of chopping power.

The electric device 120 is connected to the distributed power source 110 and the power system to supply electrical energy produced by the distributed power source 110 to the power system or to receive electrical energy from the power system to supply the distributed power source 110 ) may include a power converter for storage. As an example, if the distributed power source 110 is a solar module, the electrical energy produced is direct current, and the power system is alternating current, so the electric device 120 may be a two-phase or three-phase inverter that converts direct current to alternating current. . In addition, when the distributed power source 110 is an energy storage system, since the electrical energy of the energy storage system is direct current, the electric device 120 may be a two-phase or three-phase inverter that converts direct current to alternating current, but the energy storage system In order to charge, the electric device 120 may convert alternating current to direct current in order to supply electrical energy from the power system to the energy storage system. When the distributed power source 110 is a wind power generator, the electrical energy produced is alternating current, and the power system is also AC, but since the frequency of the electrical energy produced by the wind generator and the electrical energy of the power system may be different, the electrical device 120 It may be a cycloconverter that converts alternating current into alternating current.

The electrical device 120 may adjust the voltage and frequency of the grid connection point by controlling reactive power and active power of the grid connection point to which the electrical device 120 and the power system are connected. In the existing power system composed of centralized power generation facilities, it was easy to predict the output of the power generation facilities and control the frequency and voltage, so it was easy to respond to power quality deterioration such as voltage and frequency fluctuations of the power system caused by an imbalance in power supply and demand. However, it is becoming difficult to respond to power quality deterioration due to an imbalance in power supply and demand that occurs when power generation facilities using new and renewable energy sources with high variability are introduced into the existing power system. The electric device 120 may contribute to improving power quality by adjusting the voltage and frequency of the grid connection point when power quality degradation occurs in the power system. As an example, when the voltage of the power system is low, the electric device 120 supplies reactive power to the grid connection point to increase the voltage at the grid connection point, thereby contributing to increasing the voltage of the power system, and the voltage of the power system If high, the electric device 120 may contribute to reducing the voltage of the power system by absorbing reactive power at the grid-tied point and reducing the voltage at the grid-tied point. In addition, when the frequency of the power system is low, the electric device 120 contributes to increasing the frequency of the power system by supplying active power to the grid connection point, and when the frequency of the power system is high, the electric device 120 It contributes to reducing the frequency of the power system by lowering the active power at the connection point or consuming the active power of the grid connection point by charging the energy storage system inside the distributed power source 110 connected to the electric device 120. can

The first measuring unit 130 measures information about the distributed power supply 110, such as voltage, current, frequency, and temperature of the distributed power supply 110, and stores the measured values in a memory in a time sequence in a first time series. can be stored as data. The first measuring unit 130 may generate first time-series data by storing the measured value of the distributed power supply 110 as it is, or generate first time-series data by filtering or scaling the measured value. may be The first measuring unit 130 may further include an ADC (Analog-Digital-Converter) to obtain the first time-series data.

The second measurement unit 140 measures information on the grid connection point, such as voltage, current, frequency, and temperature of the grid connection point, which is the connection point between the electrical device 120 and the power system, and displays the measured values in chronological order. Accordingly, it may be stored as second time-series data in the memory. The second measurement unit 140 may generate second time-series data by storing the measured values of grid connection points as they are, or may generate second time-series data by filtering or scaling the measured values. The second measuring unit 140 may further include an ADC (Analog-Digital-Converter) to obtain the second time-series data.

The third measurement unit 150 may measure a control signal transmitted from the control unit 170 to the electric device 120 and store the measured value as third time series data in a memory according to a time sequence. The control signal may be transmitted to the electric device 120 in the form of active power values and reactive power values to control active power and reactive power at a grid connection point where the electric device 120 and the power system are connected. In addition, the control signal can directly control the electric device 120 in the form of a PWM (Pulse Width Modulation) signal to control active power and reactive power at a grid connection point where the electric device 120 and the power system are connected. . The third measuring unit 150 may generate third time series data by storing the measured value of the control signal as it is, or may generate third time series data by filtering or scaling the measured value. The third measuring unit 150 may further include an ADC (Analog-Digital-Converter) to obtain the third time-series data.

The communication unit 160 may receive a control method for the electric device 120 from an upper system, such as a power system operator, and transmit it to the control unit 170 . After receiving the control method, the control unit 170 may control the electrical device 120 by generating a control signal suitable for the electrical device 120 . In addition, the communication unit 160 receives only information about the power system from an upper system, such as a power system operator, and transmits it to the control unit 170, and the control unit 170 receives the information obtained by the first measurement unit 130. The electrical device 120 autonomously determines based on the first time series data, the second time series data obtained by the second measurement unit 140, and the third time series data obtained by the third measurement unit 140. can control.

6 is a configuration diagram of a distributed power supply device and system for providing simultaneous multiple services composed of two according to an embodiment.

Referring to FIG. 6 , a plurality of distributed power supply devices and systems for providing the simultaneous multi-service may form one virtual system. The communication unit 170 may transmit information of the distributed power supply device and system for providing the simultaneous multiple service, or receive information from another distributed power supply device and system for providing the simultaneous multiple service.

2 is a configuration diagram of a distributed power supply device and a system control unit for simultaneous multi-service provision according to an embodiment.

Referring to FIG. 2 , the control unit 270 may include a control method setting unit 271, a control strategy setting unit 272, a calculation unit 273, and an output unit 274.

The electrical device 120 may provide a service capable of improving power quality of the power system by adjusting electrical characteristics of the electrical device 120 and a grid connection point connected to the power system. It can be set in the method setting unit 271.

4 is an example of a control method that can be set in a control method setting unit according to an embodiment.

Referring to FIG. 4, the control methods that can be set in the control method setting unit include Active Power Set, Reactive Power Set, Volt-VAR, Volt-Watt, Frequency-Watt, Low/High Voltage Ride-Through (L/HVRT), Low /High Frequency Ride-Through (L/HFRT), Charge-Discharge, Maximum Power Limit, etc., and the following is an example of a control method.

As an example, the electrical device 120 receives commands for reactive power control and active power control directly from a higher system such as a power system operator through the communication unit 160 to increase reactive power and active power of a grid connection point, or can reduce Active power control service is called Active Power Set, and reactive power control service is called Reactive Power Set.

7 is a voltage-reactive power (Volt-Var) control curve at a grid connection point.

Referring to FIG. 7 , when the reactive power is increased at the grid-connected point, the voltage at the grid-connected point decreases, and when the reactive power is decreased at the grid-connected point, the voltage at the grid-connected point increases. When the voltage of the power system is low, the electrical device 120 may contribute to increasing the voltage of the power system by supplying reactive power to the grid connection point to increase the voltage at the grid connection point, and when the voltage of the power system is high The electric device 120 may contribute to reducing the voltage of the power system by absorbing reactive power at the grid connection point and reducing the voltage at the grid connection point. This service is called the Volt-Var control method.

8 is a voltage-active power (Volt-Watt) control curve at a grid connection point.

Referring to FIG. 8 , when the active power is decreased at the grid-connected point, the voltage at the grid-connected point increases. When the voltage of the power system is too high, there are cases in which the voltage of the grid connection point cannot be reduced to a desired level only by controlling the reactive power through the Volt-Var control method. At this time, the electric device 120 lowers the active power at the grid connection point or, when the energy storage system is included in the electric device 120, charges the energy storage system inside the distributed power source 110 to connect the grid. By consuming the active power of the point, it can contribute to reducing the voltage of the power system. This service is called the Volt-Watt control method.

When the frequency of the power system is low, the electric device 120 contributes to increasing the frequency of the power system by supplying active power to the grid connection point, and when the frequency of the power system is high, the electric device 120 is connected to the grid If the active power is lowered at the point or the energy storage system is included in the electric device 120, the energy storage system inside the distributed power source 110 is charged to consume the active power of the grid connection point, and the power system can contribute to reducing the frequency of This service is called the Frequency-Watt control method.

Even in an abnormal situation in the power system, the distributed power source 110 is connected to the power system to supply electrical energy, or stores the electrical energy of the power system in the distributed power source 110 and contributes to improving the abnormal situation of the power system, or The impact on the power system can be mitigated by slowly disconnecting it from the power grid at intervals. A service in which the distributed power source 110 is connected to the power system and operates in an abnormal situation of power system voltage is referred to as a low/high voltage ride-through (L/HVRT) control method. In addition, a service in which the distributed power source 110 is connected to the power system and operates in an abnormal situation of power system frequency is referred to as a low/high frequency ride-through (L/HFRT) control method.

When the distributed power source 110 is composed of a renewable energy source, since the prediction of power generation is uncertain, the power of the distributed power source 110 is limited to reduce the uncertainty of the prediction of power generation. In addition, if the maximum output of the distributed power source 110 is limited, the power generation facilities that can be accommodated by the power system can be increased. This service is referred to as a maximum power limit control method.

When the distributed power source 110 includes an energy storage system, electrical energy of the power system can be stored in the distributed power source 110, and the electrical energy of the distributed power source 110 can be supplied to the power system. A charge-discharge control method can be set so that the energy storage system included in the distributed power source 110 can be charged or discharged with electric energy. When the power price is low, electric energy is stored in the energy storage system included in the distributed power source 110, and when the power price is high, the electric energy is supplied to the power system to pursue maximum profits.

The control strategy setting unit 272 may set standards for selecting the control methods set by the control method setting unit 271, that is, services for the power system.

5 is an example of a control strategy that can be set by a control strategy setting unit according to an embodiment.

Referring to FIG. 5, examples of control strategies that can be set in the control strategy setting unit include compliance with commands received from the power system, pursuit of maximum profit in the power market, suppression of aging of distributed power sources, suppression of aging of electric devices, and minimization of fluctuations in the power system. There may be, and the following is an explanation of an example.

As an example, when compliance with a command received from the power system is set as the first priority in the control strategy, the electric device 120 sets the control method setting unit 271 to operate by receiving a command directly from the power system operator, which is a higher level system. You can choose from services such as Active Power Set and Reactive Power Set.

In the case of setting the pursuit of maximum profit in the power market as the first priority in the control strategy, if the upper system, the power system operator, pays an additional price when receiving the desired service from the power system, the control method set by the control method setting unit 271 Among them, control methods that obtain the maximum profit can be selected.

When suppressing aging of the distributed power supply is set as the first priority as a control strategy, the use of the distributed power supply 110 is limited to the maximum in order to suppress the aging of the distributed power supply 110, or the control set by the control method setting unit 271 Among the methods, only a control method that does not significantly affect aging may be selected based on the information of the distributed power source 110, that is, the first time-series data.

When the aging suppression of the electric device is set as the first priority as a control strategy, the use of the electric device 120 is limited to the maximum to suppress the aging of the electrical device 120, or the control set by the control method setting unit 271 Among the methods, only a control method that does not significantly affect the aging of the electrical device 120 may be selected.

When minimizing fluctuations to the power system is set as the first priority as a control strategy, among the control methods set by the control method setting unit 271 based on the information of the grid connection point, that is, the second time-series data, the power system A control method with less influence can be selected. In addition, before the control signal is calculated by the control unit 170 based on the selected control method and transmitted to the electrical device 120, information on the control signal currently controlling the electrical device 120, that is, the third time series Based on the data, the control signal can be limited or recalculated so that the fluctuation in the power system is not large.

The calculation unit 273 is configured to obtain the first time-series data and the first time-series data for information about the distributed power supply 110 such as voltage, current, frequency, and temperature of the distributed power supply 110 acquired by the first measuring unit 230. The second time-series data and the third measurement unit for the grid connection point, such as the voltage, current, frequency, temperature, etc. Based on the third time series data for the control signal transmitted from the control unit 170 to the electric device 120 measured by 150 and the information obtained from the communication unit 260, it can be provided to the power system One or more control methods can be selected and a control signal optimized for the power system can be calculated. One or more control methods that can be provided to the power system are selected from among the control methods set by the control method setting unit 271, and the criterion for selecting the control method is the control strategy set by the control strategy setting unit 272. can be based on priority. As an example, when the distributed power source 110 is configured as an energy storage system, the control strategy setting unit 272 may set the first control strategy to seek maximum profit in the electric power market, and the control method setting unit ( 271), control methods such as Charge-discharge, Volt-VAR, and Volt-Watt can be set. The communication unit 260 may receive the electricity price in real time from the power system operator, which is a higher level system, and transmit it to the calculation unit 273. Since the control strategy setting unit 272 sets the pursuit of maximum profit as the first priority in the control strategy, the calculation unit 272 calculates the power price received from the power system operator, which is the upper system, through the communication unit 260. Based on this, it can be determined whether it is advantageous to purchase electrical energy, that is, to charge electrical energy, or to sell electrical energy, that is, to discharge electrical energy. When the power price is low, the calculation unit 273 may determine that it is advantageous to purchase electric energy. Since a charge-discharge control method for charging and discharging electric energy is set in the control method setting unit 271, the calculation unit 273 operates the electric device 120 to charge the distributed power supply 110 with electric energy. The control signal to be delivered to can be calculated. Based on the first time-series data measured by the first measuring unit 230, the state of the distributed power source 110 may be grasped and an appropriate charging current may be calculated. The calculation unit 273 generates a control signal of the electric device 120 based on the calculated charging current and transfers it to the output unit 274 . Before transmission, the effect on the power system can be confirmed based on the control signal controlling the electrical device 120, that is, the third time series data, and the control signal can be recalculated if necessary. Here, the control signal may be a value of active power or reactive power, or may be a Pulse Width Modulation (PWM) signal.

The output unit 274 may serve to directly control the electrical device 120 by receiving a control signal of the electrical device 120 transmitted from the calculation unit 273 . Depending on the configuration of the electrical device 120 , the output unit may be electrically insulated from the calculation unit 120 .

3 is a flowchart of a method for providing simultaneous multiple services of a distributed power supply and system according to an embodiment.

Referring to FIG. 3 , the method for providing simultaneous multiple services of the distributed power supply and system may include a setting step (S310), a measurement step (S320), a calculation step (S330), and a control step (S340).

The setting step (S310) includes a control method setting step of setting one or more control methods for controlling the electric device 120, and a method for actually controlling the electric device 120 among the control methods set in the control method setting step. A control strategy setting step of setting criteria for selecting one or more control methods may be further included.

The control method setting step is Volt-Var, Volt-Watt, Frequency-Watt, Low/High Voltage, Ride-Through (L/HVRT), Low/High Frequency, Ride-Through (L/HFRT), Maximum Power Limit, A control method such as charge-discharge, that is, a service that the electric device 120 can provide to the power system can be set.

The control strategy setting step is to select the control method in the calculation step (S330), such as compliance with commands received from the power system, pursuit of maximum profit in the power market, suppression of aging of distributed power sources, suppression of aging of electrical devices, and minimization of fluctuations in the power system. standards can be set.

In the measuring step (S320), information about the distributed power source 110, such as voltage, current, frequency, temperature, etc., of the distributed power source 110 is measured, and the measured value is stored as first time series data in a memory according to time order. can be saved In addition, information on the grid connection point, such as the voltage, current, frequency, and temperature of the grid connection point, which is the connection point between the electric device 120 and the power system, is measured, and the measured values are stored in the memory in chronological order as a second time series. can be stored as data. In addition, the controller 170 may measure a control signal transmitted to the electric device 120 and store the measured value as third time series data in a memory according to a time sequence. In addition, in the measuring step (S320), information on the power system may be received from an upper system through communication, or information may be received or transmitted from a distributed power supply device and system for providing other simultaneous multiple services.

In the calculation step (S330), the first time series data, the second time series data, the third time series data measured in the measurement step, information obtained through communication, and the control strategy set in the setting step (S310) One or more control methods set in the setting step (S320) may be selected.

In the control step (S340), the electric device 120 may be controlled based on the control signal for controlling the electric device 120 calculated in the calculation step (S330).

Terms such as "comprise", "comprise" or "having" described above mean that the corresponding component may be inherent unless otherwise stated, and therefore do not exclude other components. It should be construed that it may further include other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, unless defined otherwise. Commonly used terms, such as terms defined in a dictionary, should be interpreted as consistent with the meaning in the context of the related art, and unless explicitly defined in the present invention, they are not interpreted in an ideal or excessively formal meaning.

The above description is merely an example of the technical idea of the present invention, and various modifications and variations can be made to those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (15)

A distributed power source composed of renewable energy or an energy storage system capable of generating or storing electrical energy;
an electric device connected to the distributed power source and the power system to supply electrical energy from the distributed power source to the power system or to supply electrical energy from the power system to the distributed power source;
a first measuring unit that is connected to the distributed power source and obtains first time-series data for a measured value of the distributed power source;
a second measuring unit that is connected to a grid connection point, which is a connection point between the electric device and the power system, and obtains second time-series data for a measured value of the grid connection point;
a third measurement unit that is connected to the control unit and obtains third time-series data for values at which the control unit controls the electric device;
A communication unit that exchanges information with a higher level system or other distributed power supply and system;
a control unit controlling the electric device based on the first time series data, the second time series data, the third time series data, and information received from the communication unit;
Distributed power supply and system for providing simultaneous multiple services including. According to claim 1,
The electric device,
While converting the alternating current of the distributed power supply to the alternating current of the power system or converting the direct current of the distributed power supply to the alternating current of the power system, electrical characteristics such as voltage and frequency of the grid connection point, which is the connection point between the electrical device and the power system, are adjusted Distributed power supply and system for simultaneous multi-service provision. According to claim 1,
The first measuring unit,
an ADC (Analog-Digital-Converter) connected to the distributed power supply to obtain the first time-series data by converting information about the distributed power supply, such as voltage, current, and temperature, into a digital signal;
Distributed power supply and system for providing simultaneous multiple services including. According to claim 1,
The second measuring unit,
an ADC (Analog-Digital-Converter) that is connected to the power system and obtains the second time-series data by converting information about the grid connection point, such as voltage, current, and frequency, into a digital signal;
Distributed power supply and system for providing simultaneous multiple services including. According to claim 1,
The third measuring unit,
It is connected between the controller and the electric device and converts information on an output signal of the controller for controlling the electric device, such as an active power control signal, a reactive power control signal, or a PWM (Pulse Width Modulation) control signal, into a digital signal. ADC (Analog-Digital-Converter) to acquire 3 time series data;
Distributed power supply and system for providing simultaneous multiple services including. According to claim 1,
The communication department,
Receive the distributed power supply and system operation command from the upper system;
receiving power price information from an upper system so that the distributed power supply and system can trade power;
A distributed power supply device and system for providing simultaneous multiple services that can receive information on power system status from a higher-level system. According to claim 1,
The communication department,
Distributed power supply for providing simultaneous multi-services capable of exchanging information with a plurality of distributed power supply units and systems so that a plurality of the distributed power supply units and systems can gather and operate as one huge virtual distributed power supply unit and system and system. According to claim 1,
The control unit,
Control method setting unit for setting the service provided to the power system;
a control strategy setting unit that sets priority standards for services provided to the power system;
Power system based on the first time series data obtained by the first measurement unit, the second time series data obtained by the second measurement unit, the third time series data obtained by the third measurement unit, and the information provided by the communication unit a calculation unit that calculates a service provided to;
an output unit connected to the electrical device and outputting a control signal for controlling the electrical device;
Distributed power supply and system for providing simultaneous multiple services including. According to claim 8,
The control method setting unit,
At the grid connection point where the power system and the electrical device are connected, reactive power and active power are controlled, the power factor of the electrical device is controlled, the maximum power of the electrical device is limited, or the distributed power is charged when the energy storage system is used. setting a control method so that the electric device operates as intended, such as controlling over-discharge;
Distributed power supply and system for providing simultaneous multiple services including. According to claim 8,
The control strategy setting unit,
In selecting the control methods set in the control method setting unit, such as compliance with commands received from the power system, pursuit of maximum profit in the power market, suppression of aging of distributed power sources, suppression of aging of electrical devices, and minimization of fluctuations in the power system, the criteria and priorities are determined. Distributed power supply and system for providing multiple services at the same time. In a method for a device to provide simultaneous multiple services,
Set control methods for controlling the electrical devices so that the electrical devices connected to the distributed power supply can provide service to the power system, and set a control strategy that is the standard for selecting and selecting one or more control methods among the control methods. setting step;
a measurement step of obtaining information necessary for calculation in order to calculate a control signal for controlling the electric device;
Based on the information measured in the measuring step, among the control methods set in the setting step, a control method is selected and selected based on the control strategy set in the setting step, and a control signal for controlling the electric device is calculated. step;
a control step of controlling the electric device with the calculated control signal;
Simultaneous multi-service providing method comprising a. According to claim 11,
In the setting step,
A control method setting step of setting a control method for controlling the electric device, such as active power, reactive power, power factor control, and charge/discharge control of the distributed power supply, at a grid connection point that is a connection point between the electric device and the power system;
The criteria for selecting and selecting the control method set in the control method setting step, such as compliance with commands received from the power system, pursuit of maximum profit in the power market, suppression of aging of distributed power sources, suppression of aging of electrical devices, and minimization of fluctuations in the power system, etc. Control strategy setting step to set;
Simultaneous multi-service providing method comprising a. According to claim 11,
In the measuring step,
acquiring information about the distributed power sources, such as voltage, current, and temperature of the distributed power sources, as first time-series data;
obtaining information about a grid connection point, such as voltage, current, and frequency, as second time series data;
Obtaining a control signal transmitted from the controller to the electric device, such as an active power control signal, a reactive power control signal, or a PWM (Pulse Width Modulation) control signal, as third time series data;
Obtaining information through communication with a higher level system or other distributed power supply and system;
Simultaneous multi-service providing method comprising a. According to claim 11,
In the measuring step,
ADCs (Analog-Digital-Converters) for acquiring the first time-series data, the second time-series data, and the third time-series data;
Simultaneous multi-service providing method comprising a. According to claim 11,
In the calculation step,
Based on the information obtained through communication, the first time series data, the second time series data, and the third time series data, and based on the control strategy, one or more control methods are selected and controlled to control the electric device. calculating the signal;
Simultaneous multi-service providing method comprising a.

Images