CN220475417U - Island protection measurement and control device - Google Patents

Abstract

The utility model provides an anti-islanding protection measurement and control device which comprises a measurement current and voltage acquisition module, a measurement processing module, a switching value input acquisition module, a switching value output module, a protection current and voltage and frequency acquisition module, a communication module and a microprocessor CPU. The modules and the microprocessor CPU can establish data connection between the grid connection part of the distributed power generation system and the background terminal, compare the current, voltage and frequency for protecting the power grid side with protection fixed value parameters, and output instructions to the switching value output module according to the comparison result. The utility model can realize island protection functions such as overvoltage protection, low-voltage protection, over-frequency protection, low-frequency protection, reverse power protection, automatic closing with pressure and the like on the grid-connected position of the distributed power generation system, improves the safety and stability of the power grid, and protects the stable operation of the power grid.

Description

Island protection measurement and control device

Technical Field

The utility model relates to the technical field of power system automation, in particular to an anti-islanding protection measurement and control device.

Background

The optimal mode of utilizing solar energy is photovoltaic conversion, namely, photovoltaic effect is utilized, so that sunlight irradiates on a silicon material to generate current to directly generate electricity. Photovoltaic power stations are one of the main forms of solar energy application, and the price and environmental protection advantages of the photovoltaic power stations are gradually reflected in the use process.

The photovoltaic power station has a larger and larger duty ratio in a power system, and the photovoltaic power station not only has centralized large-area photovoltaic, but also has distributed small-sized photovoltaic power stations. The large and medium-sized photovoltaic power stations are all built with substations, and the substations are provided with complete microcomputer protection devices, so that when faults occur, corresponding microcomputer protection can act timely and accurately. The installation capacity of a distributed power generation system, such as a small photovoltaic power station, is smaller, and a matched substation is not generally built for low-voltage grid connection.

In carrying out the utility model, the inventors have found that at least the following problems exist in the prior art: when the distributed power generation system and the power distribution network are in grid-connected operation, the power quality of the power distribution network can be greatly influenced, and an island effect exists. The damage of island effect is mainly: the voltage and the frequency of the distributed power generation system are out of control, and the power generation device and the power grid equipment are damaged.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems in the related art to a certain extent.

Therefore, the utility model aims to provide an anti-islanding protection measurement and control device which can automatically detect data at grid connection positions of a distributed power generation system, and when islanding occurs, the grid connection points are cut off rapidly, so that the distributed power generation system can leave the power grid side rapidly.

In order to achieve the above purpose, the present utility model provides an anti-islanding protection measurement and control device, comprising:

the measuring current and voltage acquisition module is used for acquiring current and voltage for metering at the power grid side;

the measuring processing module is connected with the measuring current and voltage acquisition module and is used for calculating and obtaining an electric quantity value and an electric energy value used by field electric equipment according to the current and the voltage for metering;

the switching value input acquisition module is used for completing the acquisition of the switching state data of the on-site electric equipment;

the switching value output module is used for executing the power on or power off of the field electric equipment according to the instruction;

the protection current voltage and frequency acquisition module is used for acquiring current, voltage and frequency for protecting a power grid side and transmitting the current, voltage and frequency to the CPU;

the communication module is communicatively coupled with the microprocessor CPU and is used for transmitting the switching state data of the field electric equipment to the microprocessor CPU and transmitting instructions to the switching value output module;

and the microprocessor CPU is used for establishing data connection between the grid connection part of the distributed power generation system and the background terminal, comparing the current, voltage and frequency for protecting the power grid side with the protection constant value parameters, and outputting instructions to the switching value output module according to the comparison result.

According to the island protection measurement and control device, through the arrangement of the protection current voltage and frequency acquisition module, the microprocessor CPU and the switching value output module, island protection functions such as overvoltage protection, low-voltage protection, over-frequency protection, low-frequency protection, reverse power protection, automatic closing with pressure and the like can be realized at the grid-connected position of the distributed power generation system. The anti-islanding protection measurement and control device can complete collection, calculation and analysis of protection current, voltage and frequency, and meanwhile can complete collection, calculation and analysis of measurement current, voltage for metering, so that anti-islanding protection of a distributed power generation system is realized, safety and stability of a power grid are improved, and stable operation of the power grid is protected.

According to one embodiment of the utility model, the communication module comprises an RS485 communication module and/or an ethernet communication module.

According to one embodiment of the utility model, the anti-islanding protection measurement and control device further comprises a man-machine interaction module which is communicatively coupled with the microprocessor CPU and is used for parameter setting, running state display, communication state display and man-machine interaction operation of the anti-islanding protection measurement and control device.

According to one embodiment of the utility model, the system further comprises a parameter data storage module which is communicatively coupled with the microprocessor CPU and is used for storing protection constant value parameters, fault waveforms and event records of the anti-islanding protection measurement and control device.

According to one embodiment of the utility model, the system further comprises a clock module communicatively coupled with the microprocessor CPU for time recording and timing of the anti-islanding protection measurement and control device.

According to one embodiment of the utility model, the man-machine interaction module comprises keys, an indicator light and a display screen.

According to one embodiment of the utility model, the parameter data storage module is connected with the microprocessor CPU through an SPI bus.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the utility model.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the utility model. Also, like reference numerals are used to designate like parts throughout the figures. Wherein:

fig. 1 is a schematic structural diagram of an anti-islanding protection measurement and control device according to an embodiment of the utility model.

Reference numerals illustrate:

the system comprises a 1-microprocessor CPU, a 2-measurement current and voltage acquisition module, a 3-measurement processing module, a 4-switching value input acquisition module, a 5-switching value output module, a 6-protection current, voltage and frequency acquisition module, a 7-man-machine interaction module, an 8-parameter data storage module, a 9-RS485 communication module, a 10-clock module and an 11-Ethernet communication module.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model. On the contrary, the embodiments of the utility model include all alternatives, modifications and equivalents as may be included within the spirit and scope of the appended claims.

Fig. 1 is a schematic structural diagram of an anti-islanding protection measurement and control device according to an embodiment of the utility model.

Referring to fig. 1, an anti-islanding protection measurement and control device in an embodiment of the utility model comprises a microprocessor CPU1, a measurement current and voltage acquisition module 2, a measurement processing module 3, a switching value input acquisition module 4, a switching value output module 5 and a protection current, voltage and frequency acquisition module 6.

The measuring current and voltage acquisition module 2 is used for acquiring current and voltage for metering at the power grid side. In one embodiment, the grid current is collected using a current transformer and the grid voltage is collected using a voltage transformer. The measurement processing module 3 is connected with the measurement current and voltage acquisition module 2 and is used for calculating and obtaining an electric energy value and an electric energy value used by field electric equipment according to the current and the voltage for metering. The measurement processing module 3 may be implemented by a three-phase ac power metering chip. In one embodiment, the metering chip model is RN7302, which may provide ac metering, calculation of primary and secondary values of full wave, fundamental active power, active, reactive power, and power factor. The switching value input collection module 4 is used for completing the switch state data collection of the field electric equipment, and the switching value input collection module 4 generally comprises a transient voltage suppression diode and an isolation circuit, wherein the transient voltage suppression diode prevents overvoltage and surge, protects an input port from being damaged, and the isolation circuit isolates high voltage from an internal microprocessor. The switching value output module 5 is used for executing the power on or power off of the field electric equipment according to the instruction, and a relay is arranged in the switching value output module 5, so that the power supply of the field electric equipment can be switched on or off. The protection current voltage and frequency acquisition module 6 is used for acquiring current, voltage and frequency for power grid side protection and transmitting the current, voltage and frequency to the microprocessor CPU1. The protection current voltage and frequency acquisition module 6 and the measurement current voltage acquisition module 2 acquire current and voltage on the power grid side, but the measurement accuracy and the use are inconsistent, and the two modules are independent. The communication module is communicatively coupled to the microprocessor CPU1 for transmitting switching state data of the field consumer to the microprocessor CPU1 and for transmitting commands to the switching value output module 5. The microprocessor CPU is used for establishing data connection between the grid connection position of the distributed power generation system and the background terminal, comparing the current, voltage and frequency for protecting the power grid side with the protection constant value parameters, and outputting instructions to the switching value output module 5 according to the comparison result. According to the analysis and calculation of the current, the voltage and the frequency, the island protection functions such as overvoltage protection, low-voltage protection, over-frequency protection, low-frequency protection, reverse power protection, automatic closing under pressure and the like can be realized at the grid-connected position of the distributed power generation system.

According to the anti-islanding protection measurement and control device, through the arrangement of the protection current voltage and frequency acquisition module, the microprocessor CPU and the switching value output module, islanding protection functions such as overvoltage protection, low-voltage protection, over-frequency protection, low-frequency protection, reverse power protection, automatic closing with pressure and the like can be achieved at the grid-connected position of the distributed power generation system. The anti-islanding protection measurement and control device can complete collection, calculation and analysis of protection current, voltage and frequency, and meanwhile can complete collection, calculation and analysis of measurement current, voltage for metering, so that anti-islanding protection of a distributed power generation system is realized, safety and stability of a power grid are improved, and stable operation of the power grid is protected.

In some embodiments, the communication module comprises an RS485 communication module 9 and/or an ethernet communication module 11. The RS485 communication module 9 and the ethernet communication module 11 are different in the application. The RS485 communication module 9 can be connected to an RS485 bus network, is economical and convenient to networking, and can be directly communicated with a PC or a communication manager in a networking way. The ethernet communication module 11 may access a 100MB ethernet communication interface, and may be directly connected to a local area network or a wide area network. In one example, the microprocessor CPU1 is connected with the RS485 communication module 9 through a 2-way UART serial port channel, so as to improve communication reliability, and communicate with an upper computer according to a MODBUS RTU protocol and a serial port IEC103 protocol, and upload data information and fault information. The upper computer belongs to a background terminal, and can display more abundant and comprehensive terminal information of field electric equipment. In addition, the background terminal can also comprise a mobile phone, and the mobile phone can display the terminal information of the field electric equipment through the corresponding APP, so that remote control is realized, and the convenience of operation is improved.

In some embodiments, the anti-islanding protection measurement and control device further comprises a man-machine interaction module 7, wherein the man-machine interaction module 7 is communicatively coupled with the microprocessor CPU1 and is used for parameter setting, running state display, communication state display and man-machine interaction operation of the anti-islanding protection measurement and control device. Specifically, the man-machine interaction module 7 may include a key, an indicator light and a display screen, where the indicator light may perform different display configurations according to different operation states of the anti-islanding protection measurement and control device, for example, flashing, lighting up and extinguishing, and the display screen may select a large liquid crystal screen to display chinese and english information.

The anti-islanding protection measurement and control device further comprises a parameter data storage module 8, wherein the parameter data storage module 8 is communicatively coupled with the microprocessor CPU1 and is used for storing protection fixed value parameters, fault waveforms and event records of the anti-islanding protection measurement and control device, the parameter data storage module 8 is a nonvolatile memory, and data are not lost after power failure.

In addition, the anti-islanding protection measurement and control device further comprises a clock module 10, wherein the clock module 10 is communicatively coupled with the microprocessor CPU1 and is used for time recording and time synchronization of the anti-islanding protection measurement and control device.

In some embodiments, the parameter data storage module 8 is connected with the microprocessor CPU1 through an SPI bus, and has a simple structure, easy implementation and good expandability. The microprocessor CPU1 is connected with the Ethernet communication module 11 through an RMII interface (simplified media independent interface), the data bit width is 2 bits, the occupied pin number is small, the data bit width is communicated with an upper computer according to a MODBUS TCP protocol and an Ethernet IEC103 protocol, and data information and fault information are uploaded. The microprocessor CPU1 is connected with the switching value input acquisition module 4 and the switching value output module 5 through independent I2C buses, the microprocessor CPU1 is connected with the clock module 10 through independent I2C buses, the microprocessor CPU1 is connected with the man-machine interaction module 7 through independent I2C buses, and the I2C buses have the advantages that information can be transmitted through only two wires, and hardware circuits are simplified.

It should be noted that in the description of the present utility model, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Furthermore, in the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

In the description of the present utility model, the azimuth or positional relationship indicated by the terms "left", "right", "front", "rear", etc., are based on the azimuth or positional relationship shown in the drawings, are merely for convenience of description of the present utility model and to simplify the description, and do not indicate or imply that the apparatus or element referred to must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present utility model.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and further implementations are included within the scope of the preferred embodiment of the present utility model in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present utility model.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present utility model have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the utility model.

Claims (7)

1. An anti-islanding protection measurement and control device, comprising:

the measuring current and voltage acquisition module (2) is used for acquiring current and voltage for metering at the power grid side;

the measuring processing module (3) is connected with the measuring current and voltage acquisition module (2) and is used for calculating and obtaining an electric quantity value and an electric energy value used by field electric equipment according to the current and the voltage for metering;

the switching value input acquisition module (4) is used for completing the acquisition of the switching state data of the field electric equipment;

the switching value output module (5) is used for executing the power on or power off of the field electric equipment according to the instruction;

the protection current voltage and frequency acquisition module (6) is used for acquiring current, voltage and frequency for power grid side protection and transmitting the current, voltage and frequency to the microprocessor CPU (1);

the communication module is communicatively coupled with the microprocessor CPU (1) and is used for transmitting the switching state data of the field electric equipment to the microprocessor CPU (1) and transmitting instructions to the switching value output module (5);

and the microprocessor CPU (1) is used for establishing data connection between the grid connection part of the distributed power generation system and the background terminal, comparing the current, voltage and frequency for protecting the power grid side with the protection constant value parameters, and outputting instructions to the switching value output module (5) according to the comparison result.

2. The anti-islanding protection measurement and control device according to claim 1, characterized in that the communication module comprises an RS485 communication module (9) and/or an ethernet communication module (11).

3. The anti-islanding protection measurement and control device according to claim 1, further comprising a man-machine interaction module (7), wherein the man-machine interaction module (7) is communicatively coupled with the microprocessor CPU (1) and is used for parameter setting, running state display, communication state display and man-machine interaction operation of the anti-islanding protection measurement and control device.

4. The anti-islanding protection measurement and control device according to claim 1, further comprising a parameter data storage module (8), said parameter data storage module (8) being communicatively coupled with said microprocessor CPU (1) for storing protection setpoint parameters, fault waveforms and event records of said anti-islanding protection measurement and control device.

5. The anti-islanding protection measurement and control device according to claim 1, further comprising a clock module (10), said clock module (10) being communicatively coupled with said microprocessor CPU (1) for time recording and timing of said anti-islanding protection measurement and control device.

6. An anti-islanding protection measurement and control device according to claim 3, characterized in that the man-machine interaction module (7) comprises keys, indicator lights and a display screen.

7. The anti-islanding protection measurement and control device according to claim 4, characterized in that the parameter data storage module (8) is connected with the microprocessor CPU (1) through an SPI bus.