KR102145330B1 - Monitoring System and Method for Management of Forward and Reverse Distributed Energy Resources - Google Patents

Abstract

The present invention relates to a monitoring system for managing a two-way distributed power supply and a method thereof. The two-way distributed power supply monitoring system effectively monitor a charging and discharging state of the two-way distribution power supply such as an electric vehicle battery in small facilities such as schools, public facilities, apartment houses, homes, factories, buildings, and the like, and monitors power conversion efficiency of a power conversion system (PCS) in real time. The charging and discharging state of the two-way distributed power supply can be intuitively checked in the field to effectively perform management of the two-way distributed power supply and to be usefully used for charging and discharging the two-way distributed power supply such as the electric vehicle battery.

Description

Monitoring System and Method for Management of Forward and Reverse Distributed Energy Resources}

The present invention relates to a system for managing bidirectional distributed power, and in particular, to a monitoring system and method for managing bidirectional distributed power such as an electric vehicle battery, which is a bidirectional distributed power supply.

The proportion of electric energy among the energy consumption that has been continuously increasing in recent years is gradually increasing, and installation of new power generation and transmission facilities is restricted due to environmental and cost issues. As one of the methods to solve this problem, distributed energy resources (DER) technology is in the spotlight.

Distributed power refers to a facility capable of supplying power so that the load connected to the power system can operate separately from the main generator installed in the power system, and such distributed power has a short construction period and cannot respond to peak loads. It is high and has the advantage of low transmission loss. Here, the distributed power supply is to reduce energy loss and transmission and distribution facilities by installing small power generation facilities near energy end users or inside buildings. Such distributed power generation may correspond to solar power generation, fuel cell power generation, and wind power generation. In addition, with the development of communication technology, it is now possible to implement a distributed power supply at an economical scale through automatic remote operation.

A plurality of such distributed power sources are installed in the distribution system to transmit the distributed power output to the distribution system, and the output voltage output from the distributed power source to the distribution system varies according to the amount of power generated by the distributed power source. The electric vehicle charging/discharging device, which is a two-way distributed power supply among distributed power sources, functions as a charge (V2G) of the electric vehicle charging/discharging device from the system and discharging from the electric vehicle charging/discharging device to the customer side, that is, the reverse transmission function, ensuring power quality and discharging. The reverse power control from the mode to the grid side must be properly performed.

Therefore, there is a need for a management system to effectively charge and discharge (reverse transmission) of the electric vehicle charging/discharging device.

Accordingly, the present invention was conceived to solve the above problems, and an object of the present invention is a monitoring system capable of effectively and usefully managing charging and discharging (reverse transmission) in a bidirectional distributed power source such as an electric vehicle battery. And to provide a method.

First, summarizing the features of the present invention, a two-way distributed power monitoring system according to an aspect of the present invention for achieving the above object is a charge/discharge that performs power monitoring to perform power monitoring in the charge/discharge mode of the two-way distributed power supply. Management system; A two-way distributed power module for supplying power to a customer load through a distribution board using a two-way distributed power that can be charged using power provided from the power system; And for AC power supplied from the power system between the power system and the distribution panel to be charged with the bidirectional distributed power supply, power quality monitoring data for measurement elements is transmitted to the charge/discharge management system, and the power quality of the measurement element And a distributed power system connection protection device for controlling the AC power in a normal state to flow from the power system using monitoring data, and the bidirectional distributed power module comprises: a first amount of power supplied from the bidirectional distributed power supply and And a power efficiency meter for transmitting information on a result of measuring the second amount of power supplied from the power system and a result of calculating the power conversion efficiency of the power conversion device to the charge/discharge management system.

The charge/discharge management system performs power monitoring based on the first and second amount of power, the power conversion efficiency, and the power quality monitoring data of the measurement element, and provides monitoring information and power demand for the customer load and It performs prediction of power supply and demand and provides prediction results.

The two-way distributed power monitoring system is operated in a plurality of facilities, respectively, through an integrated monitoring system interlocking with a plurality of two-way distributed power monitoring systems, the first and second amount of power of each facility, the power conversion efficiency, and the Based on the measurement factor power quality monitoring data, it is possible to provide monitoring information for each of the entire facilities, perform prediction of power demand and power supply and demand for the total customer load in the entire facility, and provide a prediction result.

The bidirectional distributed power supply includes an electric vehicle battery or an energy storage device.

The measurement element power quality monitoring data includes one or more of phase voltage, phase current, line voltage, active power, reactive power, apparent power, power factor, frequency, amount of active power, or amount of reactive power.

The abnormal state out of the normal state includes one or more of an overvoltage (OVR), a undervoltage (UVR), an overfrequency (OFR), a low frequency (UFR), or reverse power (RPR).

The power efficiency meter calculates the power conversion efficiency in a charging direction and a reverse transmission discharging direction according to a power direction mode for which one of a charging mode from AC to DC or a discharge mode from DC to AC It can be transmitted to the charge/discharge management system together with the direction mode.

The power efficiency meter may store the first and second amounts of power and the power conversion efficiency in a storage unit at a predetermined period and transmit the first and second electric power amounts to the charge/discharge management system at the predetermined period.

The power efficiency meter includes a display unit for displaying the first and second power amounts and the power conversion efficiency, and displays alarm information on the display unit when the input/output voltage or current value of the power conversion device deviates from a prescribed value, and the It can be transmitted to the charge/discharge management system.

The distributed power system connection protection device includes: a measurement element measurement monitoring unit for receiving an AC voltage detected from a voltage sensing unit and an AC current detected from the current sensing unit, and measuring at least one measurement element; And a control unit for controlling to transmit the measurement element power quality monitoring data including the value of the measurement element measured by the measurement element measurement monitoring unit to the charge/discharge management system through a transmission unit at a predetermined period, the control unit , With respect to the AC power from the power system using the power quality monitoring data of the measurement element, in an abnormal state in which the value of the measurement element is out of the range of the specified value for the power system connection connection, a trip event is generated and a predetermined protection contact is established. It is operated, and the corresponding trip event occurrence time, the name and operation value of the corresponding measurement element are stored in a memory, displayed on the display, and transmitted to the charge/discharge management system.

The distributed power system linkage protection device, in a discharge mode supplying power to the customer load, to cut off power flowing from the bidirectional distributed power supply to the power system, or when a power failure occurs in the power system, the bidirectional In order to cut off power flowing from the distributed power source to the power system, a reverse power protection contact may be operated, and a state of the reverse power protection contact may be transmitted to the charge/discharge management system.

In addition, the monitoring method according to another aspect of the present invention is a two-way distributed power monitoring system including a two-way distributed power module that supplies power to a customer load through a distribution board using a two-way distributed power that can be charged using power provided from the power system. In, in the monitoring method, in the protection device between the power system and the distribution panel, for AC power supplied from the power system to be charged with the bidirectional distributed power, measurement element power quality monitoring data, the bidirectional Transmitting to a charging/discharging management system performing power monitoring performing power monitoring in the charging/discharging mode of the distributed power supply, and controlling AC power in a normal state to flow from the power system using the power quality monitoring data of the measurement element ; And in the bidirectional distributed power module, information on a result of measuring a first amount of power supplied from the bidirectional distributed power supply and a second amount of power supplied from the power system and a result of calculating the power conversion efficiency of the power converter. And transmitting to the charge/discharge management system.

According to the two-way distributed power monitoring system according to the present invention, for example, it efficiently monitors the charging and discharging state of the two-way distributed power supply such as electric vehicle batteries in small facilities such as schools, public facilities, apartment houses, homes, factories, and buildings, and PCS The power conversion efficiency of the (Power Conversion System, power conversion device) can be monitored in real time, and the charging and discharging status of the bidirectional distributed power can be intuitively checked at the site. It can be usefully used for charging and discharging bidirectional distributed power.

The accompanying drawings, which are included as part of the detailed description to aid understanding of the present invention, provide embodiments of the present invention and describe the technical spirit of the present invention together with the detailed description.
1 is a block diagram of a two-way distributed power monitoring system according to an embodiment of the present invention.
2 is a block diagram of a bidirectional power efficiency meter according to an embodiment of the present invention.
3 is a diagram illustrating a principle of recognizing a power direction of a DC detection unit of a power efficiency meter in a charging mode according to an embodiment of the present invention.
4 is a diagram illustrating a principle of recognizing a power direction of a DC detection unit of a power efficiency meter in a discharge mode according to an embodiment of the present invention.
5 is a block diagram of a distributed power system interconnection protection device according to an embodiment of the present invention.
6 is a view for explaining a control method in a charge and discharge mode of a charge/discharge management system in a bidirectional distributed power monitoring system according to an embodiment of the present invention.
7 is a view for explaining an example of a method of implementing a two-way distributed power monitoring system according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In this case, the same components in each drawing are indicated by the same reference numerals as possible. In addition, detailed descriptions of functions and/or configurations already known are omitted. In the following, a part necessary for understanding an operation according to various embodiments will be mainly described, and descriptions of elements that may obscure the subject matter of the description will be omitted. In addition, some elements of the drawings may be exaggerated, omitted, or schematically illustrated. The size of each component does not fully reflect the actual size, and therefore, the contents described herein are not limited by the relative size or spacing of the components drawn in each drawing.

In describing the embodiments of the present invention, when it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention and may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout this specification. The terms used in the detailed description are only for describing the embodiments of the present invention, and should not be limiting. Unless explicitly used otherwise, expressions in the singular form include the meaning of the plural form. In this description, expressions such as "comprising" or "feature" are intended to refer to certain features, numbers, steps, actions, elements, some or combination thereof, and one or more other than those described. It should not be construed to exclude the presence or possibility of other features, numbers, steps, actions, elements, any part or combination thereof.

In addition, terms such as first and second may be used to describe various components, but the components are not limited by the terms, and the terms are used to distinguish one component from other components. Is only used.

1 is a block diagram of a bidirectional distributed power monitoring system 500 according to an embodiment of the present invention.

Referring to FIG. 1, a bidirectional distributed power monitoring system 500 according to an embodiment of the present invention is coupled between a power system 10 that supplies power from an outside and a customer load 20 that consumes power, It includes a distribution panel 200 for power distribution and a distributed power system connection protection device 300 that controls and manages the connection between the two-way distributed power supply 110 and the power system 10, and the distribution panel 200 and It includes a two-way distributed power module 100 that is connected to supply power through a distributed power supply. The two-way distributed power module 100 includes a two-way distributed power supply 110, a power conversion device (PCS) 120, and a power efficiency meter 130. In addition, the two-way distributed power monitoring system 500, the two-way distributed power supply 110, the power efficiency meter 130, and the distributed power system linkage protection device 300 and the necessary communication signals and interworking, charging and discharging management system It further includes 400. The above components of the two-way distributed power monitoring system 500 may be installed and operated in various small-scale facilities such as schools, public facilities, apartment houses, homes, factories, and buildings. However, in some cases, the server-type charge/discharge management system 400 may be properly installed and operated on a communication network even if it is not inside the facility. In the present invention, the communication network is a wired/wireless network that supports wired Internet communication or wireless Internet communication such as WiFi and WiBro, and mobile communication such as WCDMA and LTE in order to be able to interwork with each other by a communication signal as needed. It may include.

In addition, on such a communication network, a two-way distributed power monitoring system 500 can be installed in various small-scale customer facilities such as schools, public facilities, apartment houses, homes, factories, and buildings, respectively, and monitoring a plurality of such two-way distributed power sources. The systems may be managed and controlled by interworking on a communication network by an integrated monitoring system (not shown) in the form of a server as a whole.

The two-way distributed power supply 110 includes batteries of one or more electric vehicles connected to the two-way distributed power module 100 installed in various small customer facilities such as schools, public facilities, apartment houses, homes, factories, and buildings, and , It may be one or a plurality of charge-dischargeable energy storage devices (ESS, Energy Storage System) installed in the bi-directional distributed power module 100.

The power conversion device 120 converts DC power from the bidirectional distributed power supply 110 into AC power according to the power direction mode (in reverse transmission and discharge mode). According to the power direction mode (in the charging mode), the power conversion device 120 may convert AC power of the power system 10 supplied through the distribution panel 200 into DC power. In the case of an emergency in which the supply is interrupted due to a power outage of the power system 10 in the discharge mode, the power conversion device 120 can independently operate without cooperation with the power system 10. The power conversion device 120 may detect a power direction mode according to the negative and positive values of the voltage/current at both ends of the sensing element such as a shunt resistor.

The power efficiency meter 130 measures the amount of power output from the bidirectional distributed power supply 110 in the discharge mode (reverse transmission) according to the power direction mode, and the power conversion efficiency from DC to AC of the power converter 120. Information on the calculated result is transmitted to the charge/discharge management system 400 together with the power direction mode. In order to charge the bi-directional distributed power supply 110 in the charging mode, the power conversion device 120 converts the AC power of the power system 10 supplied through the distribution panel 200 into DC power to the bi-directional distributed power supply 110. Even when providing, the power efficiency meter 130 displays information about the amount of power for the output DC power of the power conversion device 120 and the result of calculating the power conversion efficiency from AC to DC of the power conversion device 120 in the power direction. It is transmitted to the charge/discharge management system 400 together with the mode. The power efficiency meter 130 may detect the power direction mode according to the negative and positive values of the voltage/current at both ends using a sensing element such as a shunt resistor.

The distribution board 200 selectively selects any one of the AC power from the power conversion device 120 and the AC power from the power system 10 supplied through the distributed power system linkage protection device 300 according to the operating state. It is distributed to the customer load (20). The customer load 20 may be any electric (or power) device that can be used in various small customer facilities such as schools, public facilities, apartment houses, homes, factories, and buildings.

The two-way distributed power module 100 uses a two-way distributed power supply 110 such as a battery of an electric vehicle or an energy storage device that charges and stores the power provided from the power system 10, through the distribution board 200, the customer load 20 ) Can supply power. The charge/discharge management system 400 may control the operation of the bidirectional distributed power module 100. Under the control of the charge/discharge management system 400, the bidirectional distributed power module 100 may control the charging/discharging operation of the bidirectional distributed power supply 110. For example, the charge/discharge management system 400 can control the charging of the bidirectional distributed power supply 110 to be operated at night time (eg, 11PM~06AM, etc.) where the electric charge is low, and the bidirectional distributed power supply 110 The discharge can be controlled to operate during the day or peak hours (eg, 06AM~11PM, etc.) when the electric charge is high, or in an emergency when the power supply from the system is interrupted.

The distributed power system connection protection device 300 may transmit power quality monitoring data of measurement elements in the charging mode to the charging/discharging management system 400 between the power system 10 and the distribution board 200. In the discharge mode, the distributed power system connection protection device 300 operates a reverse power protection contact to block power flowing from the bi-directional distributed power supply 110 to the power system 10 through the power conversion device 120. In addition, when a power outage occurs on the power system 10, the distributed power system connection protection device 300 senses this and reverse power to cut off the power flowing from the bidirectional distributed power supply 110 to the power system 10. Operate the protective contact. At this time, in the discharge mode, the distributed power system connection protection device 300 may transmit the reverse power protection contact state to the charge/discharge management system 400.

In addition, the distributed power system connection protection device 300 is supplied from the power system 10 through the distribution panel 200 in the charging mode, and for AC power to be charged with the bidirectional distributed power supply 110, phase voltage, phase current, line-to-line Measure each value of measurement elements such as voltage, active power, reactive power, apparent power, power factor, frequency, active power, and reactive power, and measure the power quality monitoring data of the measurement elements including the values of each measured measurement element. It transmits to the charge/discharge management system 400. In addition, the distributed power system connection protection device 300, using the measurement element power quality monitoring data, with respect to the AC power supplied from the power system 10 and charged with the bidirectional distributed power supply 110, overvoltage (OVR) , When abnormal conditions such as low voltage (UVR), over frequency (OFR), low frequency (UFR), and reverse power (RPR) occur, in order to inject normal AC power and block the abnormal power, a trip event signal is generated, It is possible to perform control, such as protection contact.

The charge/discharge management system 400 receives information about the result of measuring the amount of electricity in both directions (charging mode, discharge mode) and the calculation result of the power conversion efficiency of the power conversion device 120 from the power efficiency meter 130, and Receiving reverse power protection contact status and measurement element power quality monitoring data from the power system linkage protection device 300, and the charge/discharge management system 400 receiving such information, the power amount, power conversion efficiency, and reverse power of each corresponding facility Power monitoring is performed, such as analysis of power quality through power protection contact status, measurement element power quality monitoring data, and, if necessary, predicts the power demand for the customer load 20 and uses the amount of power in the customer facility for the power demand. By doing so, it is possible to predict the power supply and demand (information related to whether or not the demand is satisfied), and provide the forecast result, and provide monitoring information for inquiry requests and control necessary for optimal system operation of the distributed resource plant. Perform. Power demand for a predetermined period can be predicted based on the power consumption of the customer load 20 of each customer facility, and for the calculated power demand, the electric power supply and demand for a predetermined period can be predicted using the amount of electricity of the customer facility. This is possible.

In addition, the charge/discharge management system 400 may control the operation of the bidirectional distributed power module 100 by receiving power direction mode (charging mode/discharging mode) information from the bidirectional distributed power module 100. Under the control of the charge/discharge management system 400, the bidirectional distributed power module 100 may control the charging/discharging operation of the bidirectional distributed power supply 110. For example, the charge/discharge management system 400 can control the charging of the bidirectional distributed power supply 110 to be operated at night time (eg, 11PM~06AM, etc.) where the electric charge is low, and the bidirectional distributed power supply 110 The discharge can be controlled to operate during the day or peak hours (eg, 06AM~11PM, etc.) when the electric charge is high, or in an emergency when the power supply from the system is interrupted.

In addition, each of the plurality of bidirectional distributed power monitoring systems 500 on the communication network may be managed and controlled in conjunction with an integrated monitoring system (not shown). For example, the integrated monitoring system (not shown) receives each power amount, power conversion efficiency, reverse power protection contact status, and power quality monitoring data of measurement elements from the two-way distributed power monitoring system 500 of each customer facility. , For example, the integrated monitoring system (not shown) may identify the amount of power that can be supplied by each customer facility and provide monitoring information for each of the corresponding entire facility in response to an inquiry request. The integrated monitoring system (not shown) predicts the total power demand for the total customer load at the entire facility, and the total power demand calculated based on the power consumption at the customer load 20 of each customer facility. Since the total power supply and demand is predicted using the power amount of each customer's facility and the forecast result is provided, more accurate and reliable power demand and supply and demand monitoring is possible.

2 is a block diagram of a bidirectional power efficiency meter 130 according to an embodiment of the present invention.

Referring to FIG. 2, a bidirectional power efficiency meter 130 according to an embodiment of the present invention includes a DC detection unit 131, an AC detection unit 132, a measurement unit 133, a control unit 134, and a transmission unit 135. , A storage unit 136, and a display unit 137 may be included.

Each component of the bidirectional power efficiency meter 130 may be implemented by hardware such as a semiconductor processor, software such as an application program, or a combination thereof. In addition, the controller 134 in charge of overall control may be implemented to include one or more functions among other constituent elements, and some functions of the controller 134 may be implemented in the form of separate constituent elements as other units. The storage unit 136 stores data or setting information necessary for the operation of the bidirectional power efficiency meter 130. The display unit 137 includes a display device such as an LCD and an LED for displaying each data processed by the control unit 134 as necessary.

The DC detection unit 131 outputs direct current (DC) power output from the bidirectional distributed power supply 110 in the discharge mode (or when the power flows in the direction of charging the bidirectional distributed power supply 110 in the charging mode). It detects voltage or current for DC power). The DC detector 131 may detect a voltage or current for DC power using a predetermined DC sensor. In addition, the DC detection unit 131 may include a sensing element 139 such as a shunt resistor for detecting a power direction mode according to the negative and positive values of the voltage/current at both ends as shown in FIGS. 3 and 4.

3 is a diagram for explaining a principle of recognizing a power direction of the DC detector 131 of the power efficiency meter 130 in a charging mode according to an embodiment of the present invention.

4 is a diagram for explaining a principle of recognizing a power direction of the DC detector 131 of the power efficiency meter 130 in a discharge mode according to an embodiment of the present invention.

As shown in FIGS. 3 and 4, the DC detection unit 131 may detect the voltage or current at both ends of the sensing element 139 such as a shunt resistance, and the measurement unit 133 of the power efficiency meter 130 is the sensing element 139 The power direction mode (charging mode/discharging mode) can be determined according to the negative and positive signs of the voltage or current at both ends of ), and the corresponding value can be output.

For example, as shown in FIG. 3, when the voltage applied to both ends of the sensing element 139 such as a shunt resistance is -0.032 V, and the resistance value of the sensing element 139 such as a shunt resistance is 4 mΩ, a sensing element such as a shunt resistor ( Since the current value flowing through 139 is -8A, the measurement unit 133 may recognize that the charging mode (or transmission direction) is and output a corresponding digital value. In addition, as shown in FIG. 4, when the voltage applied to both ends of the sensing element 139 such as a shunt resistor is +0.032V, and the resistance value of the sensing element 139 such as a shunt resistor is 4mΩ, the sensing element 139 such as a shunt resistor Since the current value flowing in is +8A, the measurement unit 12 may recognize that it is in the discharge mode (or the receiving direction (forward direction)) and output a corresponding digital value.

On the other hand, the AC detection unit 132, AC power after the DC power output from the bi-directional distributed power supply 110 in the discharge mode is converted to AC power by the power converter 120 (or bi-directional dispersion in the charging mode) When the power flows in the direction of charging the power supply 110, voltage or current is detected for AC power of the power system 10 supplied through the distribution panel 200 ). The AC detection unit 132 may detect a voltage or current for AC power using a predetermined AC sensor.

According to the power direction mode, when the power converter 120 converts DC power into AC power and outputs it in the discharge mode, the measurement unit 133 detects a value of the AC power output from the AC detection unit 132 The amount of power output from the bi-directional distributed power supply 110 is measured based on. In addition, the measurement unit 133 compares the value detected for the DC power output from the DC detection unit 131 in the discharge mode with the value detected for the AC power output from the AC detection unit 132 to compare the power conversion device 120 Calculate the power conversion efficiency of (DC to AC power conversion efficiency).

For both directions according to the power direction mode (charging mode or discharging mode), the measurement unit 133 includes input voltage and current values according to the power flow direction of the power conversion device 120 (e.g., bidirectional distributed power sources such as solar cell modules ( 110) to calculate the input DC power by measuring the output voltage and current value), and by measuring the output voltage and current of the power converter 120 to calculate the output AC power, and the input DC power and the output AC power The power conversion efficiency can be calculated through the ratio of

That is, according to the power direction mode (charging mode or discharging mode), when the power converter 120 converts AC power into DC power and outputs it in the charging mode, the DC power output from the DC detection unit 131 The amount of power supplied is measured based on the detected value. In addition, the measurement unit 133 compares a value detected for the AC power output from the AC detection unit 132 with a value detected for the DC power output from the DC detection unit 131 to determine the power of the power conversion device 120 Calculate conversion efficiency (power conversion efficiency from AC to DC).

The storage unit 136 stores the input/output voltage/current of the power conversion device 120 output from the measurement unit 133 under the control of the control unit 134, the power amount measurement result, and the power conversion efficiency calculation result at a predetermined period (e.g., Save and manage as 1 minute, 10 minutes, 1 hour, etc.).

The control unit 134 also converts the input/output voltage/current of the power conversion device 120, the power amount measurement result, and the power conversion efficiency calculation result at a predetermined period (eg, 1 minute, 10 minutes, 1 hour, etc.). Control to transmit to the charge/discharge management system 400 through the transmission unit 135 together with the direction mode (information on which direction is the charge mode or the reverse transmission/discharge mode). The transmission unit 135 may include a communication module such as a modem for transmitting and receiving a necessary signal with the charge/discharge management system 400.

The display unit 137 may display a voltage or current for the DC power detected by the DC detection unit 131 and a voltage or current for the AC power detected by the AC detection unit 132 under the control of the control unit 134. have. In addition, the display unit 137 may display a result of measuring the amount of power output from the measurement unit 133 and a result of calculating the power conversion efficiency under the control of the controller 134. When an event occurs in which the input voltage and current values of the power conversion device 120 or the output voltage and current values of the power conversion device 120 deviate from the specified values, the control unit 134 alarms in a predetermined form through the display unit 137 You can control the display to be made. At this time, the control unit 134 controls to transmit alarm information (corresponding values, specified values, difference values, etc.) for values out of the corresponding specified values to the charge/discharge management system 400 through the transmission unit 135.

In the present invention, the measurement unit 133 directly measures the input/output voltage or current value of the power conversion device 120 in both directions (power flow from AC (DC) to DC (AC)) to convert not only the amount of power supplied but also the power. Even the power conversion efficiency of the device 120 can be obtained. Since the amount of power that can be supplied from the bidirectional distributed power source 110 such as an electric vehicle battery or an energy storage device may change at any time, it is important to monitor the amount of power supplied and the power conversion efficiency.

5 is a configuration diagram of a distributed power system interconnection protection device 300 according to an embodiment of the present invention.

Referring to FIG. 5, a distributed power grid-connected protection device 300 according to an embodiment of the present invention includes a voltage sensing unit (PT, Power Transformer) 310, a current sensing unit (CT, Current Trabsformer) 320. ), a measurement element measurement monitoring unit 330, a control unit 340, may include a transmission unit 350.

Each component of the distributed power system connection protection device 300 may be implemented by hardware such as a semiconductor processor, software such as an application program, or a combination thereof. In addition, the control unit 340 in charge of overall control may be implemented to include one or more functions among other components, and some functions of the control unit 340 may be implemented in the form of separate components as other units.

When the AC power flows from the power system 10 to the power conversion device 120 through the distribution panel 200, the voltage sensing unit 310 uses a predetermined device (eg, PT, Power Transformer), AC voltage is detected.

When the AC power flows from the power system 10 to the power conversion device 120 through the distribution board 200, the current detection unit 320 uses a predetermined device (eg, CT, Current Transformer), The corresponding alternating current is detected.

The measurement element measurement monitoring unit 330 is supplied from the power system 10 through the distribution board 200 in the charging mode and detected from the voltage sensing unit 310 for AC power to be charged with the bidirectional distributed power supply 110. By receiving the AC voltage and the AC current detected from the current sensing unit 320, the measurement elements such as phase voltage, phase current, line voltage, active power, reactive power, apparent power, power factor, frequency, active power amount, reactive power amount, etc. Measure each value.

The control unit 340 transmits the measurement element power quality monitoring data including the value of each measurement element, measured by the measurement element measurement monitoring unit 330, at a predetermined period (eg, 1 minute, 10 minutes, 1 hour, etc.). Control to transmit to the charge/discharge management system 400 through the transmission unit 350. The transmission unit 350 may include a communication module such as a modem for transmitting and receiving a necessary signal with the charge/discharge management system 400.

In addition, the control unit 340 of the distributed power system connection protection device 300 uses the power quality monitoring data of the measurement elements as described above, and is supplied from the power system 10 to be charged with the bidirectional distributed power supply 110. On the other hand, if an abnormal condition occurs when the value of the measurement element is out of the range of the specified value for the power system connection connection such as overvoltage (OVR), undervoltage (UVR), overfrequency (OFR), low frequency (UFR), and reverse power (RPR). , In order to introduce normal AC power and block abnormal power inflow, a trip event is generated and a predetermined protection contact is operated, and the corresponding trip event occurrence time, the name and operation value of the corresponding measurement element are stored in the memory, and the display unit And can be transmitted to the charge/discharge management system 400.

In addition, the control unit 340, in the discharging mode, the distributed power system connection protection device 300 is reversed to cut off the power flowing from the bi-directional distributed power supply 110 to the power system 10 through the power conversion device 120. Activate the power protection contact. In addition, when a power outage occurs on the power system 10, the controller 340 detects this and operates a reverse power protection contact to cut off the power flowing from the bidirectional distributed power supply 110 to the power system 10. The controller 340 may transmit the state of the reverse power protection contact to the charge/discharge management system 400.

6 is a view for explaining a control method in the charging mode and the discharge mode of the charge/discharge management system 400 in the bidirectional distributed power monitoring system 500 according to an embodiment of the present invention.

Referring to FIG. 6, first, in the bidirectional distributed power monitoring system 500, the power direction mode (charging mode or discharging mode) is connected to the bidirectional distributed power supply module 100 and the distributed power system according to the operation settings of the operator and the user. It may be set, such as the protection device 300 (S110). The set power direction mode (charge mode or discharge mode) information may be notified to the charge/discharge management system 400. In addition, the power conversion device 120 and the power efficiency meter 130 may determine the power direction mode (charging mode/discharging mode), and each of the power direction mode (charging mode or discharging mode) information is provided by a charging/discharging management system ( 400). The charge/discharge management system 400 may control charging and discharging operations of the bidirectional distributed power supply module 100 by receiving information on the power direction mode (charging mode/discharging mode) as described above.

In the charging mode, the charge/discharge management system 400 receives and charges the amount of power, power conversion efficiency, and power quality monitoring data of measurement elements in real time from the power efficiency meter 130 and the distributed power system connection protection device 300 Until this is completed, power monitoring such as power quality analysis is performed (S111).

In order to charge the bi-directional distributed power supply 110 in the charging mode, the power conversion device 120 converts the AC power of the power system 10 supplied through the distribution panel 200 into DC power to the bi-directional distributed power supply 110. When providing, the power efficiency meter 130 displays information about the amount of power for the output DC power of the power conversion device 120 and the result of calculating the power conversion efficiency from AC to DC of the power conversion device 120 in the power direction. It is transmitted to the charge/discharge management system 400 together with the mode.

In addition, the distributed power system connection protection device 300 is supplied from the power system 10 through the distribution panel 200 in the charging mode, and for AC power to be charged with the bidirectional distributed power supply 110, phase voltage, phase current, line-to-line Measure each value of measurement elements such as voltage, active power, reactive power, apparent power, power factor, frequency, active power, and reactive power, and measure the power quality monitoring data of the measurement elements including the values of each measured measurement element. It transmits to the charge/discharge management system 400. In addition, the distributed power system connection protection device 300, with respect to the AC power supplied from the power system 10 to be charged with the bidirectional distributed power supply 110 using the measurement element power quality monitoring data, the value of the measurement element If an abnormal condition outside the range of the power system linkage connection such as over voltage (OVR), under voltage (UVR), over frequency (OFR), low frequency (UFR), and reverse power (RPR) occurs, normal AC power is introduced. In order to prevent the inflow of abnormal power, a trip event is generated and a predetermined protection contact is operated, and the corresponding trip event occurrence time, the name and operation value of the corresponding measurement element are stored in the memory and displayed on the display, charge/discharge management system It can be transmitted to 400.

In the discharge mode, the charge/discharge management system 400 first monitors the state of the power system 10 in order to supply power from the bidirectional distributed power supply 110 such as an electric vehicle battery or an energy storage device to the customer load 20. (S120). The charge/discharge management system 400, in the case of an emergency in which the supply is interrupted due to a power failure of the power system 10 in the discharge mode, the power conversion device 120 performs independent operation without cooperation with the power system 10 A control signal may be transmitted to supply power to the customer load 20 (S121), and a control signal may be transmitted so that the distributed power system linkage protection device 300 opens the power system 10 (S122).

When the power system 10 is normal, the charge/discharge management system 400 interlocks with the distributed power system connection protection device 300 to request information necessary for monitoring, so that the distributed power system connection protection device 300 Controls to operate the reverse power protection contact to cut off the power flowing from the distributed power supply 110 to the power system 10 (S130), and the bidirectional distributed power supply 110 of the bidirectional distributed power module 100 starts discharging. Control to be performed (S130). At this time, the distributed power system connection protection device 300 may transmit the reverse power protection contact state to the charge/discharge management system 400.

In the discharge mode, the power efficiency meter 130 measures the input/output voltage/current of the power converter 120 and the amount of power output from the bidirectional distributed power supply 110 in the discharge mode (reverse transmission) according to the power direction mode. And transmits information on the result of calculating the power conversion efficiency from DC to AC by the power conversion device 120 to the charge/discharge management system 400 together with the power direction mode (S140). The charging/discharging management system 400 comprises the bidirectional distributed power supply 110 of the bidirectional distributed power module 100 to stop discharging when the input/output voltage/current of the power conversion device 120, the amount of power, and power conversion efficiency are out of the normal range. A control signal can be transmitted to (S151). Otherwise, if the discharge to the customer load 20 is smoothly performed in the discharge mode, the charge/discharge management system 400 continues monitoring while maintaining the discharge state (S150).

Meanwhile, when comparing the conventional general system and the bidirectional distributed power monitoring system 500 of the present invention, as shown in [Table 1], first, a DC meter in a current general solar power generation system measures DC voltage, DC current, and power However, there is no meter that measures the power conversion efficiency that can measure the power conversion efficiency of the entire system when it is converted to an AC power grid through an inverter. KEPCO AC meter and DC meter were installed and charged separately, so there was a problem that the power conversion efficiency could not be known in real time from the system side.

division Prior art The present invention Advantages of the present invention Meter occupied space Separate installation of AC/DC (2 units) AC/DC integration (1 unit) 50% savings
(2 units-->1 units) Meter power consumption Separate AC/DC consumption AC/DC integrated consumption 50% savings
(2 units-->1 units) Efficiency measurement method Top EMS (Energy Management System) (S/W) Two-way distributed power field measurement (H/W), or EMS system Site-centric, intuitive Efficiency measurement range Unit PCS input measurement Power conversion efficiency of the entire system of bidirectional distributed power Customer-oriented Reverse power measurement One-way Bidirectional possible Easy to identify reverse power Maintenance No alarm display function Alarm can be displayed through the power efficiency meter when PCS input/output power exceeds the specified value. Easy to understand alarm

As described above, the bidirectional distributed power monitoring system 500 of the present invention has excellent advantages compared to the prior art in terms of occupied space, reduced power consumption, improved efficiency measurement method, efficiency measurement range, measurement direction, and maintenance. Compared with the method of measuring power conversion efficiency in a monitoring system such as an upper EMS after measuring using two conventional DC and AC meters, the occupied space is reduced to 1/2 by implementing it in one meter 130, and Power consumption can be reduced by 1/2. Also, based on the input measurement for the existing unit PCS, the measurement of the power conversion efficiency, which was performed by the upper EMS, etc., can be measured in the field from the side of the entire system of the bidirectional distributed power supply, and the measurement in the direction of charging the bidirectional distributed power supply 110 Two-way measurement such as measurement with the load 120 is possible, and reverse power measurement is possible, and by reducing the number of units to one, it is possible to reduce the possibility of failure and shorten the maintenance period. 7 is a view for explaining an example of an implementation method of the bidirectional distributed power monitoring system 500 according to an embodiment of the present invention.

Among the two-way distributed power monitoring system 500 according to an embodiment of the present invention, the power efficiency meter 130, the distributed power system connection protection device 300, the charge/discharge management system 400, and the integrated monitoring system include hardware, It can be made of software, or a combination thereof. For example, the power efficiency meter 130, the distributed power system interconnection protection device 300, the charge/discharge management system 400, and the integrated monitoring system of the present invention are at least for performing the above functions/steps/processes. It may be implemented in the form of a computing system 1000 as shown in FIG. 7 having one processor or a server on the Internet.

The computing system 1000 includes at least one processor 1100, a memory 1300, a user interface input device 1400, a user interface output device 1500, a storage 1600, and a network connected through the bus 1200. An interface 1700 may be included. The processor 1100 may be a central processing unit (CPU) or a semiconductor device that processes instructions stored in the memory 1300 and/or the storage 1600. The memory 1300 and the storage 1600 may include various types of volatile or nonvolatile storage media. For example, the memory 1300 may include a read only memory (ROM) 1310 and a random access memory (RAM) 1320.

Accordingly, the steps of the method or algorithm described in connection with the embodiments disclosed herein may be directly implemented in hardware executed by the processor 1100, a software module, or a combination of the two. The software module is a storage/recording medium (i.e., memory 1300) readable by a device such as a computer, such as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, register, hard disk, removable disk, CD-ROM. Alternatively, it may reside in the storage 1600. An exemplary storage medium is coupled to the processor 1100, which can read information from and write information to the storage medium. Alternatively, the storage medium may be integral with the processor 1100. The processor and storage media may reside within an application specific integrated circuit (ASIC). The ASIC may reside within the user terminal. Alternatively, the processor and storage medium may reside as separate components within the user terminal.

As described above, according to the two-way distributed power monitoring system 500 according to the present invention, for example, a two-way distributed power supply 110 such as an electric vehicle battery in small facilities such as schools, public facilities, apartment houses, homes, factories, buildings, etc. It efficiently monitors the charging and discharging status of the PCS, monitors the power conversion efficiency of the PCS 120 in real time, and intuitively checks the charging and discharging status of the bi-directional distributed power supply at the site, making it possible to manage the bi-directional distributed power supply 110. It is made effectively and can be usefully used for charging and discharging the bidirectional distributed power source 110 such as an electric vehicle battery.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but this is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , Anyone with ordinary knowledge in the field to which the present invention belongs will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the spirit of the present invention is limited to the described embodiments and should not be determined, and not only the claims to be described later, but also all technical ideas equivalent or equivalent to the claims are included in the scope of the present invention. Should be interpreted as.

Power system(10)
Customer load (20)
Bi-directional distributed power module (100)
Bi-directional distributed power supply (110)
Power conversion device (120)
Power efficiency meter(130)
Distribution board (200)
Distributed power system connection protection device (300)
Charge/discharge management system (400)

Claims (12)

A charge/discharge management system for performing power monitoring in a charge/discharge mode of a bidirectional distributed power supply;
A two-way distributed power module for supplying power to a customer load through a distribution board using the two-way distributed power, which can be charged using power provided from a power system; And
For AC power supplied from the power system between the power system and the distribution panel to be charged with the bidirectional distributed power supply, power quality monitoring data of measurement elements is transmitted to the charge/discharge management system, and power quality monitoring of the measurement elements It includes a distributed power system connection protection device for controlling the AC power in a normal state to flow from the power system using data,
The bidirectional distributed power module includes information on a result of measuring a first amount of power supplied from the bidirectional distributed power source and a second amount of power supplied from the power system and a result of calculating the power conversion efficiency of the power conversion device. Including a power efficiency meter transmitted to the charge and discharge management system,
The distributed power system connection protection device,
A measurement element measurement monitoring unit for receiving the AC voltage detected from the voltage sensing unit and the AC current detected from the current sensing unit, and measuring at least one measurement element; And
And a control unit for controlling to transmit the measurement element power quality monitoring data including the value of the measurement element measured by the measurement element measurement monitoring unit to the charge/discharge management system through a transmission unit at a predetermined period, the control unit, With respect to the AC power from the power system using the power quality monitoring data of the measurement element, a trip event is generated and a predetermined protection contact is operated in an abnormal state in which the value of the measurement element is outside the range of the specified value for the power system connection connection. It is a two-way distributed power monitoring system that stores the trip event occurrence time, the name of the measurement element, and the operation value in memory. The method of claim 1,
The charge/discharge management system performs power monitoring based on the first and second amount of power, the power conversion efficiency, and the power quality monitoring data of the measurement element, and provides monitoring information and power demand for the customer load and A two-way distributed power monitoring system that predicts power supply and demand and provides prediction results. The method of claim 1,
The two-way distributed power monitoring system is each operated in a plurality of facilities,
Through an integrated monitoring system interlocking with a plurality of two-way distributed power monitoring systems, based on the first and second power amounts, power conversion efficiency, and power quality monitoring data of each facility, for each of the entire facilities. A two-way distributed power monitoring system for providing monitoring information and predicting power demand and supply and demand for total customer load in the entire facility, and providing prediction results. The method of claim 1,
The two-way distributed power supply is a two-way distributed power monitoring system including an electric vehicle battery or an energy storage device. The method of claim 1,
The measurement element power quality monitoring data includes one or more of phase voltage, phase current, line voltage, active power, reactive power, apparent power, power factor, frequency, amount of active power, or amount of reactive power. The method of claim 1,
The abnormal state out of the normal state is a two-way distributed power monitoring system including one or more of an overvoltage (OVR), a low voltage (UVR), an over frequency (OFR), a low frequency (UFR), or reverse power (RPR). The method of claim 1,
The power efficiency meter,
According to the power direction mode for whether the charging mode from AC to DC or the discharge mode from DC to AC, the power conversion efficiency in the charging direction and the reverse transmission and discharging direction is calculated, and the charging is performed together with the power direction mode. Two-way distributed power monitoring system transmitted to the discharge management system. The method of claim 1,
The power efficiency meter,
A two-way distributed power monitoring system for storing the first and second amounts of power and the power conversion efficiency in a storage unit at a predetermined period and transmitting them to the charge/discharge management system at the predetermined period. The method of claim 1,
The power efficiency meter,
Includes a display unit for displaying the first and second amount of power and the power conversion efficiency, and when the input/output voltage or current value of the power conversion device deviates from a specified value, alarm information is displayed on the display unit and transmitted to the charge/discharge management system Two-way distributed power monitoring system. The method of claim 1,
The control unit displays the corresponding trip event occurrence time, the name and operation value of the corresponding measurement element on the display unit, and transmits it to the charge/discharge management system. The method of claim 1,
The distributed power system connection protection device,
Power flowing from the bidirectional distributed power source to the power system in order to block power flowing from the bidirectional distributed power source to the power system in the discharge mode supplying power to the customer load, or when a power failure occurs in the power system In order to cut off, a two-way distributed power monitoring system for operating a reverse power protection contact and transmitting the state of the reverse power protection contact to the charge/discharge management system. In a monitoring method in a two-way distributed power monitoring system including a two-way distributed power module that supplies power to a customer load through a distribution board using a two-way distributed power that can be charged using power provided from a power system,
(A) In the protection device between the power system and the distribution board, for AC power supplied from the power system and provided to be charged with the bidirectional distributed power supply, measurement element power quality monitoring data, charging/discharging of the bidirectional distributed power supply Transmitting to a charging/discharging management system performing power monitoring in a mode, and controlling AC power in a normal state to flow from the power system using the power quality monitoring data of the measurement element; And
(B) In the bidirectional distributed power module, a result of measuring the first amount of power supplied from the bidirectional distributed power supply and the second amount of power supplied from the power system and the result of calculating the power conversion efficiency of the power converter Including the step of transmitting information to the charge and discharge management system,
The step (A),
Receiving the AC voltage detected from the voltage sensing unit and the AC current detected from the current sensing unit, and measuring at least one measurement element; And
Control to transmit the measurement element power quality monitoring data including the measured value of the measurement element to the charge/discharge management system through a transmission unit at a predetermined period, from the power system using the measurement element power quality monitoring data For AC power of, in an abnormal state in which the value of the measurement element is out of the range of the specified value for the power system connection connection, a trip event is generated and a predetermined protection contact is operated, and the corresponding trip event occurrence time, the name of the measurement element and Step of storing the operation value in memory
Monitoring method comprising a.

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