KR102540280B1 - Reverse power prevention apparatus in power system - Google Patents

Abstract

The present invention relates to a device for preventing reverse power in a power system, and more particularly, to a power system that stabilizes the power system by preventing reverse power from occurring in the power system due to a high generation amount of a solar module when the power consumption of a load is low. It relates to a device for preventing reverse power.

Description

Reverse power prevention device of power system {REVERSE POWER PREVENTION APPARATUS IN POWER SYSTEM}

The present invention relates to a device for preventing reverse power in a power system, and more particularly, to a power system that stabilizes the power system by preventing reverse power from occurring in the power system due to a high generation amount of a solar module when the power consumption of a load is low. It relates to a device for preventing reverse power.

Taking the prior art related to the reverse power prevention device of the power system of the present invention as an example, the patent document 1 solar power generation system and method increase or decrease the amount of power generated by the inverter according to the output contact signal so that the reverse power relay does not operate, Photovoltaic power generation is possible.

In addition, the reverse power and power factor real-time control system of the patent document 2 photovoltaic power generation system increases the quick response to reverse power detection, monitors real-time reverse power and transmits the monitored value to each photovoltaic power generation system, or limits the amount of photovoltaic power generation. By sending commands to each inverter, it is possible to control in real time so that reverse harmonization does not occur even for a moment, and power factor charges can be reduced by actively controlling the power factor of the customer without using a phase-advancing capacitor.

However, in the prior art, the power consumption of the load is lowered, and the power consumption of the load is measured without preventing the occurrence of power failure due to the reverse power prevention of the protective relay due to the generation of reverse power in which the electricity of the solar module is transmitted to the grid. Thus, there is a problem in that the power system cannot be stabilized by turning on/off the amount of photovoltaic power generation.

Registered Patent Publication No. 10-2321901 Photovoltaic power generation system and method Registered Patent Publication No. 10-2351621 Real-time control system for reverse power and power factor of photovoltaic power generation system

An object of the present invention is to provide a device for preventing reverse power in a power system that stabilizes a power system by measuring power consumption of a load and turning on/off solar power generation.

In addition, the present invention is to provide a power system reverse power prevention device for preventing reverse power of the power system by controlling the power switch between the solar module and the inverter on / off according to the power consumption level of the load for another object. do.

Another object of the present invention is to provide an apparatus for preventing reverse power in a power system that schedules a power switch on/off sequence according to a power consumption level of a load.

ACB (Air Circuit Breaker) on the low voltage side capable of responding to overvoltage, overcurrent, and undervoltage in conjunction with the protective relay of the present invention; A circuit breaker (10) including a; high-voltage side VCB (Vacuum Circuit Breaker, Vacuum Circuit Breaker) that protects a high-voltage receptor or a transformer by detecting over-voltage, over-current, under-voltage, short circuit, or ground fault; A load 20 indicating that electricity consumes the power energy of a mechanical device or the size of the consumed energy; A photovoltaic module (60) that produces electricity using microscopic physical conversion called photovoltaic effect; And an inverter 70 that converts the generated power stored in the form of direct current in the photovoltaic module 60 into alternating current and converts it into electricity usable by the load 20; in a power system including a CT type current sensor, a sensor 30 employing the principle of converting the measured current to the load 20 into a secondary current according to the turns ratio; A power switch that level-converts the sensor value of the sensor 30, predicts the power consumption of the load 20 according to the level value, and switches and controls the amount of power generation of the solar module 60 corresponding to the predicted power consumption ( a control board 40 for controlling on/off of 50); And SCR (Silicon Controlled Rectifier), IGBT (Insulated Gate Bidirectional Transistor), by controlling on / off the connection or disconnection between the solar module 60 and the inverter 70, the power of the solar module 60 is the inverter ( 70) is supplied to or not supplied to the power switch 50; characterized in that it includes.

In addition, the control board 40, the leveling unit 41 for analog / digital conversion of the sensor value of the sensor 30, and level conversion by comparing the digital value and a threshold value; a scheduling unit 42 that schedules the on/off operation of the power switch 50 according to the level value of the leveling unit 41; and an interface unit 43 for driving on/off of the power switch 50 according to the scheduling of the scheduling unit 42.

In addition, the leveling unit 41 includes an ADC 411 for analog/digital conversion of the sensor value of the sensor 30; a comparison unit 412 that compares a digital value with a threshold value; and a level unit 413 outputting a level value according to the output of the comparison unit 412.

In addition, the scheduling unit 42, the storage unit 421 for storing the level value of the leveling unit 41; a lookup table 422 for storing the on/off map of the power switch 50 corresponding to the level value; a control unit 423 that outputs an on/off control sequence of the power switch 50 corresponding to the level value of the storage unit 421 to an output unit 424 by referring to the on/off map of the lookup table 422; and an output unit 424 outputting a control signal to the interface unit 43 according to the on/off control sequence of the control unit 423.

In addition, the step of operating the control board 40 (S101); Measuring the current value and determining whether it is forward or reverse (S102); If the direction is forward, turning on the power switch 50 (S103); Increasing solar power generation (S104); If the direction is reverse, turning off the power switch 50 (S105); Reducing solar power generation (S106); and supplying power to the load (S107).

The present invention may have an effect of stabilizing the power system by preventing reverse power to the power system by measuring the power consumption of the load and turning on/off the amount of photovoltaic power generation.

In addition, the present invention can have an effect of preventing the circuit breaker and the inverter from being turned off by preventing reverse power in the power system by on/off controlling the power switch between the solar module and the inverter according to the power consumption level of the load.

In addition, the present invention can have an effect of achieving power control that adapts to power consumption by scheduling a power switch on/off sequence according to the power consumption level of a load.

1 is a block diagram showing the configuration of a device for preventing reverse power in a power system.
FIG. 2 is an exemplary view showing a first embodiment to which a device for preventing reverse power of the power system of FIG. 1 is applied.
FIG. 3 is an exemplary view showing a second embodiment to which a device for preventing reverse power in the power system of FIG. 1 is applied.
Figure 4 is a block diagram showing the configuration of the control board of Figure 1;
5 is a block diagram showing the configuration of the leveling unit of FIG. 4;
6 is a block diagram showing the configuration of the scheduling unit of FIG. 4 .
7 is an operation flowchart of a device for preventing reverse power in the power system of FIG. 1 .
FIG. 8 is an exemplary diagram illustrating a system authentication configuration for granting authority to execute hardware resources, an operating system, an operation of a control unit, which is a core, and an operation of a control unit for explaining the present invention.
9 is an exemplary diagram showing application of a neural network to explain the present invention.

Hereinafter, an apparatus for preventing reverse power in a power system according to an embodiment of the present invention will be described in detail with reference to the drawings. Hereinafter, descriptions of conventionally known matters are omitted or simplified to clarify the gist of the present invention. The configurations included in the description of the present invention operate in individual or complex combination configurations.

1 is a block diagram showing the configuration of a device for preventing reverse power in a power system. Referring to FIG. 1, the power system includes a circuit breaker 10, a load 20, a solar module 60, and an inverter 70. And, the reverse power prevention device includes a sensor 30, a control board 40, and a power switch 50.

In the power system, the circuit breaker 10 is an ACB (Air Circuit Breaker, Air Circuit Breaker) on the low voltage side capable of responding to overvoltage, overcurrent, and undervoltage in conjunction with a protective relay; It includes a VCB (Vacuum Circuit Breaker) on the high-voltage side that protects the high-voltage receptor or transformer by detecting over-voltage, over-current, under-voltage, short circuit, or ground fault.

The load 20 represents electricity consuming power energy of a mechanical device or the size of the consumed energy. That is, devices such as devices that receive power in the electric field and devices that consume power delivered by such devices belong. The load 20 refers to products that consume electricity, such as air conditioning equipment, lights, and home appliances.

The photovoltaic module 60 generates electricity by using a physical conversion of a microscopic level called photovoltaic effect. The photovoltaic module 60 can achieve high efficiency by stacking several cells like a tandem structure, and the efficiency of a cell made of a single absorption layer rather than a stack structure is about 35%.

The inverter 70 converts the direct current generated by the solar module 60 into alternating current and converts it into electricity usable by the load 20 . The inverter 70 has to operate with the voltage of the power system and has a function to protect against sudden operation errors of the power plant.

In the device for preventing reverse power, the sensor 30 is a CT type current sensor, and adopts a principle of converting a measured current into a secondary current according to a winding ratio. The secondary current flows through the shunt resistor and a voltage is generated across the shunt resistor, and the generated voltage becomes an output proportional to the current flowing through the measuring conductor.

The control board 40 converts the level of the sensor value of the sensor 30, calculates the power consumption of the load 20 according to the level value, and controls the switching of the power generation amount of the solar module 60 corresponding to the calculated power consumption. Controls the on/off of the power switch 50 to

The power switch 50 is a SCR (Silicon Controlled Rectifier) and IGBT (Insulated Gate Bidirectional Transistor), and controls the connection or disconnection between the solar module 60 and the inverter 70 on/off to control the solar module 60. of power is supplied to or not supplied to the inverter 70.

2 is an exemplary view showing a first embodiment to which the reverse power prevention device of the power system of FIG. 1 is applied. Referring to FIG. 2, the power system includes a circuit breaker 10, a load 20, a solar module 60, Including the inverter 70, the device for preventing reverse power includes a sensor 30, a control board 40, and a power switch 50.

The inverter 70 associated with the solar module 60 generates reverse power to the power system when the solar power generated compared to the load 20 is large, detects the reverse power in the reverse power protection relay, and turns off the circuit breaker 10. . When the circuit breaker 10 is turned off, the voltage of the inverter 70 rises, the inverter 70 operates an overvoltage protection operation, and the inverter 70 stops.

In a building that uses solar power generation for its own consumption without sending it to the power system, on weekends and holidays when the power of the load 20 decreases, the protection operation operates, the circuit breaker 10 is turned off, and the inverter 70 is stopped. When the circuit breaker 10 and the inverter 70 are stopped due to a protective operation, a power failure occurs, and a manager must directly turn on the circuit breaker 10, turn on the inverter 70, and restart the load 20 to supply normal power.

In order to prevent a power outage of the load 20, the control board 40 receives the sensor value from the sensor 30 of the CT (Current Transformer) in the reverse power prevention device, and when the power consumption of the load 20 is small, sunlight Turn off the power switch 50 on the module 60 side to block reverse power, prevent the inverter 70 from forcibly stopping and put it in a standby state, and when the power consumption of the load 20 increases, the power that is turned off By turning on the switch 50, the standby inverter 70 is operated to generate power.

The inverter 70 is in a standby state, and the control board 40 controls the power switch 50 according to the power consumption of the load 20 so that the load 20 is always in an operable state without being in a power outage state. .

The power switch 50 is connected to a plurality of photovoltaic modules 60, respectively, and a plurality of photovoltaic modules 60 are connected to one inverter 70. The control board 40 sequentially turns on/off the power switch 50 according to the power consumption of the load 20 .

3 is an exemplary view showing a second embodiment to which the reverse power prevention device of the power system of FIG. 1 is applied. Referring to FIG. 3, the power system includes a circuit breaker 10, a load 20, a solar module 60, Including the inverter 70, the device for preventing reverse power includes a sensor 30, a control board 40, and a power switch 50.

In the power system, the circuit breaker 10 is an ACB (Air Circuit Breaker, Air Circuit Breaker) on the low voltage side capable of responding to overvoltage, overcurrent, and undervoltage in conjunction with a protective relay; It includes a VCB (Vacuum Circuit Breaker) on the high-voltage side that protects the high-voltage receptor or transformer by detecting over-voltage, over-current, under-voltage, short circuit, or ground fault.

The load 20 represents a thing that generates electricity or consumes power energy of a mechanical device, or the size of the consumed energy. That is, devices such as devices that receive power in the electric field and devices that consume power delivered by such devices belong.

The photovoltaic module 60 generates electricity by using a physical conversion of a microscopic level called photovoltaic effect. The photovoltaic module 60 can achieve high efficiency by stacking several cells like a tandem structure, and the efficiency of a cell made of a single absorption layer rather than a stack structure is about 35%.

The inverter 70 converts the electrical energy generated by the solar module 60 into alternating current and converts it into electricity usable by the load 20 . The inverter 70 has to operate with the voltage of the power system and has a function to protect against sudden operation errors of the power plant.

In the device for preventing reverse power, the sensor 30 is a CT type current sensor, and adopts a principle of converting a measured current into a secondary current according to a winding ratio. The secondary current flows through the shunt resistor and a voltage is generated across the shunt resistor, and the generated voltage becomes an output proportional to the current flowing through the measuring conductor.

The control board 40 converts the level of the sensor value of the sensor 30, calculates the power consumption of the load 20 according to the level value, and controls the switching of the power generation amount of the solar module 60 corresponding to the calculated power consumption. Controls the on/off of the power switch 50 to

The power switch 50 is a SCR (Silicon Controlled Rectifier) and IGBT (Insulated Gate Bidirectional Transistor), and controls the connection or disconnection between the solar module 60 and the inverter 70 on/off to control the solar module 60. of power is supplied to or not supplied to the inverter 70.

The power switch 50 is connected to a plurality of photovoltaic modules 60, respectively, and each photovoltaic module 60 is connected to a respective inverter 70. The control board 40 sequentially turns on/off the power switch 50 according to the power consumption of the load 20 .

FIG. 4 is a block diagram showing the configuration of the control board of FIG. 1 . Referring to FIG. 4 , the control board 40 includes a leveling unit 41 , a scheduling unit 42 , and an interface unit 43 .

The control board 40 includes a leveling unit 41 that converts the sensor value of the sensor 30 to analog/digital and converts the level by comparing the digital value and a threshold value; a scheduling unit 42 that schedules the on/off operation of the power switch 50 according to the level value of the leveling unit 41; and an interface unit 43 that drives on/off of the power switch 50 according to the scheduling of the scheduling unit 42.

5 is a block diagram showing the configuration of the leveling unit of FIG. 4. Referring to FIG. 5, the leveling unit 41 includes an analog-to-digital converter (ADC) 411, a comparator 412, and a level unit 413. includes

The leveling unit 41 includes an ADC 411 that converts the sensor value of the sensor 30 into analog/digital; a comparison unit 412 that compares a digital value with a threshold value; and a level unit 413 outputting a level value according to the output of the comparator 412.

6 is a block diagram showing the configuration of the scheduling unit of FIG. 4. Referring to FIG. 6, the scheduling unit 42 includes a storage unit 421, a lookup table 422, a control unit 423, and an output unit 424. do.

The scheduling unit 42 includes a storage unit 421 for storing the level value of the leveling unit 41; a lookup table 422 for storing the on/off map of the power switch 50 corresponding to the level value; a control unit 423 that outputs an on/off control sequence of the power switch 50 corresponding to the level value of the storage unit 421 to the output unit 424 by referring to the on/off map of the lookup table 422; and an output unit 424 outputting a control signal to the interface unit 43 according to the on/off control sequence of the control unit 423.

The lookup table 422 stores the power switch 50 on/off map corresponding to the level value, the power switch 50 on/off map suitable for the level value can be applied, and the amount of power generated by the solar module 60 , the power consumption of the load 20 may be considered.

7 is an operation flowchart of the reverse power prevention device of the power system of FIG. 1. Referring to FIG. 7, the reverse power prevention device includes the operation of the control board 40 (S101); Measuring the current value and determining whether it is forward or reverse (S102); If the direction is forward, turning on the power switch 50 (S103); Increasing solar power generation (S104); If the direction is reverse, turning off the power switch 50 (S105); Reducing solar power generation (S106); Step (S107) of supplying power to the load; is performed.

When the current from the CT sensor 30 is in the forward direction, electricity is supplied from the system to the load 20, and electricity generated from sunlight is supplied to minimize electricity supplied by the system and save electricity bills. When the current is in the reverse direction, the solar power generation power supplies electricity to the grid, and the electricity generated by the sunlight is not consumed by the load 20, and the surplus is passed to the grid. Therefore, the reverse power protection device reduces solar power generation by turning off the power switch 50 when the current is in the reverse direction.

FIG. 8 is an exemplary diagram illustrating a system authentication configuration for granting authority to execute hardware resources, an operating system, a core control unit, and a control unit operation for explaining the present invention. Referring to FIG. 8, the present invention is a processor (1) ), memory 2, input/output device 3, operating system 4, and control unit 5.

The processor 1 is a CPU (Central Processing Units), a GPU (Graphic Processing Unit), an FPGA (Field Programmable Gate Array), and an NPU (Neural Processing Unit). ) executes the executable code.

The memory 2 includes a permanent mass storage device such as random access memory (RAM), read only memory (ROM), disk drive, solid state drive (SSD), flash memory, etc. can do.

The input/output device 3 is an input device, such as a camera, keyboard, microphone, mouse, etc., including an audio sensor and/or an image sensor, and an output device, such as a display, speaker, haptic feedback device, etc. device may be included.

The operating system 4 may include Windows, Linux, IOS, a virtual machine, a web browser, and an interpreter, and supports tasks, threads, timer execution, scheduling, resource management, graphics, font processing, communication, and the like.

The control unit 5 determines the state of the input/output device 3 by sensor, key, touch, and mouse input under the support of the operating system 4, and performs an operation according to the determined state. The control unit 5 performs task scheduling using a timer and thread as a parallel execution routine.

The control unit 5 determines a state using the sensor value of the input/output device 3 and performs an algorithm according to the determined state.

Referring to FIG. 8 , the system authentication configuration includes a terminal 6 including a control unit 5 and an authentication server 7 . The terminal 6 may be a control board 40, the input/output device 3 may be a sensor 30 and a power switch 50, and the control unit 5 may include a leveling unit 41 and a scheduling unit 42 , interface 43 can be implemented.

The terminal 6 duplicates the data channels, receives the key value and biometric information of the terminal 6, and requests user authentication from the authentication server 7 through the first data channel. It is displayed on the display and transmitted to the authentication server (7).

The terminal 6 inputs the kit value displayed on the display of the terminal 6 and transmits it to the authentication server 7 through the second data channel along with user information. The terminal 6 requests the authentication server 7 to authenticate the system installed in the terminal 6 using the kit value and user information. The kit value of the terminal 6 can be generated from computer-specific information such as the CPU manufacturing number and the address of the Ethernet chip. The terminal 6 may obtain user information through face recognition using a camera, voice recognition using a microphone, and handwriting recognition using a display, and may use it for authentication.

The authentication server 7 receives the kit value from the terminal 6, receives the kit value and user information from the terminal 6 through a duplicated data channel, compares the kit value of the terminal 6 with the user information, and returns the user information Correspondingly, authentication for system use of the terminal 6 is processed. The authentication server 7 transmits the authentication result to the terminal 6 to allow the user to use the system. Due to the duplicated data channel of the terminal 6, loss of kit value can be minimized.

The authentication server 7 performs a history analysis of user information, and compares and determines consistency and change of user information over time. In the history analysis, if the user information shows consistency, the user's use is permitted, and if it shows change, the user's use is not permitted. When the user information shows consistency, the user's use of the system is permitted, thereby strengthening security to prevent a user whose user information has been altered from accessing the system.

The terminal 6, which is a means of authenticating the use of the system, does not directly connect to the system, but forms a detour through the authentication server 7, so that the network constituting the Internet network is composed of an internal network and an external network, and the IP address setting process When this is cumbersome, there is an advantage in that the authentication process using the terminal 6 is smoothly performed. At this time, the system is mounted on the terminal 6, the terminal 6 serves as an authentication terminal means, and the authentication server 7 serves as an authentication server means.

The cloud 12 is a modularization of the container 14 under the support of the operating system 4 that manages the processor 1, memory 2, input/output device 3, and communication unit 13, and the web 8, DB ( 9), protocol 10, and library 11 services are provided, and the control unit 5 executes a cloud application using the container 14 service. A standard software package called a container 14 bundles the application's code along with relevant configuration files, libraries 11 and the dependencies required to run the app. The cloud 12 may integrally control the control board 40 of the terminal 6 .

FIG. 9 is an exemplary view illustrating application of a neural network for explaining the present invention, and will be described with reference to FIG. 2 .

Neural network learning selects a model through feature selection and algorithm selection from time-series data collected from input devices such as various sensors such as temperature, altitude, and fingerprints, cameras such as images and infrared rays, and LIDAR, and then repeats learning and performance verification processes. Repeat model selection through trial and error. After performance verification is complete, an artificial intelligence model is selected.

The control unit 5 performs a deep learning algorithm using a neural network to determine the sensor value, uses training data to learn the neural network, and verifies the performance of the neural network with test data.

The present invention is not limited to the specific preferred embodiments described above, and various modifications can be made by anyone skilled in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes are within the scope of the claims.

1: Processor
2: memory
3: I/O device
4: operating system
5: control unit
6: Terminal
7: authentication server
8: Web
9: DB
11: library
12: cloud
13: Ministry of Communications
14: container
10: Breaker
20: load
30: sensor
40: control board
41: leveling unit
411 ADC
412: comparison unit
413: level part
42: scheduling unit
421: storage unit
422: lookup table
423: control unit
424: output unit
43: interface unit
50: power switch
60: solar panel
70: Inverter

Claims (5)

ACB (Air Circuit Breaker) on the low voltage side that can respond to overvoltage, overcurrent, and undervoltage in conjunction with a protective relay; A circuit breaker (10) including a; high voltage VCB (Vacuum Circuit Breaker, Vacuum Circuit Breaker) for protecting a high voltage receptor or a transformer by detecting overvoltage, overcurrent, undervoltage, short circuit, ground fault, etc.;
A load 20 indicating that electricity consumes the power energy of a mechanical device or the size of the consumed energy;
A photovoltaic module (60) that produces electricity using microscopic physical conversion called photovoltaic effect; and
In a power system comprising: an inverter 70 that converts the electrical energy generated by the solar module 60 into alternating current and converts it into electricity usable by the load 20,
The sensor 30, which is a CT type current sensor and adopts the principle of converting the measured current to the load 20 into a secondary current according to the winding ratio;
A power switch for converting the level of the sensor value of the sensor 30, calculating the power consumption of the load 20 according to the level value, and switching and controlling the amount of power generation of the solar module 60 corresponding to the calculated power consumption ( a control board 40 for controlling on/off of 50); and
With a Silicon Controlled Rectifier (SCR) and an Insulated Gate Bidirectional Transistor (IGBT), the connection or disconnection between the solar module 60 and the inverter 70 is controlled on/off so that the power of the solar module 60 is converted to the inverter 70. ) Power switch 50 for supplying or not supplying;
The control board 40,
a leveling unit 41 that converts the sensor value of the sensor 30 to analog/digital, compares the digital value with a threshold value, and converts the level;
a scheduling unit 42 that schedules the on/off operation of the power switch 50 according to the level value of the leveling unit 41; and
An interface unit 43 that drives on/off of the power switch 50 according to the scheduling of the scheduling unit 42; includes,
The scheduling unit 42,
a storage unit 421 for storing a level value of the leveling unit 41;
a lookup table 422 for storing the on/off map of the power switch 50 corresponding to the level value;
a control unit 423 that outputs an on/off control sequence of the power switch 50 corresponding to the level value of the storage unit 421 to an output unit 424 by referring to the on/off map of the lookup table 422; and
and an output unit 424 outputting a control signal to the interface unit 43 according to the on/off control sequence of the control unit 423. delete According to claim 1,
The leveling unit 41,
ADC 411 for analog/digital conversion of the sensor value of the sensor 30;
a comparison unit 412 that compares a digital value with a threshold value; and
A level unit 413 outputting a level value according to the output of the comparator 412; characterized in that it comprises a reverse power prevention device of a power system. delete According to claim 1,
operating the control board 40 (S101);
Measuring the current value and determining whether it is forward or reverse (S102);
If the direction is forward, turning on the power switch 50 (S103);
Increasing solar power generation (S104);
If the direction is reverse, turning off the power switch 50 (S105);
Reducing solar power generation (S106); and
An apparatus for preventing reverse power in a power system, characterized by performing the step (S107) of supplying power to the load.

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