Detailed Description
In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. Further, "connection" in the following embodiments is understood to mean "electrical connection", "communication connection", or the like, if there is a transfer of electrical signals or data between the connected objects.
As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, as used in this specification, the term "and/or" includes any and all combinations of the associated listed items. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
And in the year 2020, the information is about 12 months and 2 days, local power supply companies such as Zhenju province, Taixing and the like receive superior notifications, and are limited by consumption space according to the requirements of the notifications, and after the spring festival in 2020, Jiangsu province and commercial distributed projects (including low-voltage internet access) only allow spontaneous self-use, and the rest of electricity cannot be connected to the internet, and an anti-reflux device is required to be installed. The spontaneous self-use mode photovoltaic power generation is directly supplied to a local load, redundant power generation can not be fed to a power grid system, and GB/T19939-2005 'technical requirement for grid connection of photovoltaic systems' section 7 installation requirement indicates that 'for a grid connection mode which can not be subjected to reverse current, a reverse current detection device is required to be installed at the output end of a power supply transformer', so a user needs to install a reverse current prevention device.
The existing photovoltaic power generation reverse power control system mostly monitors voltage and current of a property right demarcation point and adjusts the output of an inverter in a communication mode. However, the scheme is only suitable for projects with the monomer capacity of below 500kWp, and is not suitable for large-scale industrial enterprises and mining enterprises with large loads, and if the reverse power protection device directly trips the grid-connected point switch, the photovoltaic power generation consumption level is not improved, and redundant electric energy generated by the power generation unit is consumed everywhere, so that the waste of photovoltaic power generation resources is caused.
The utility model discloses based on SCADA (Supervisory Control And Data Acquisition, Data Acquisition And Supervisory Control system) computer monitoring system design anti-reflux scheme, develop new functional module on the basis of the SCADA monitoring software that the producer provided, reverse power overload protection device is prevented in the cooperation, improves the user to the ability of disappearing of new forms of energy electricity generation when reaching the anti-reflux. The utility model provides a grid-connected power generation anti-reflux system can be used to the spontaneous project of forbidding the surplus electricity online of using oneself that 10kV, the monomer capacity that 35kV was incorporated into the power networks be 6MWp ~ 20MWp, also can be used to the project that the low pressure below the monomer capacity 500kWp was incorporated into the power networks.
Fig. 1 is a block diagram of a grid-connected power generation anti-reflux system according to an embodiment of the present invention, in one embodiment, the grid-connected power generation anti-reflux system includes at least one power generation unit 100, a grid-connected cabinet 200, an anti-reflux relay protection device 300, at least one sampling control unit 400, and an analysis control module 500. The at least one power generation unit 100 is connected with a user load bus through a grid-connected cabinet 200, and the grid-connected cabinet 200 is used for collecting electric energy output by the power generation unit 100 and inputting the electric energy into the user load bus; the at least one power generation unit 100 is connected to the connection path of the grid-connected cabinet 200 to form at least one collection line; and the connection point of the grid-connected cabinet 200 and the user load bus is a property right demarcation point. The anti-reflux relay protection device 300 is connected with the property right demarcation point and used for collecting and monitoring the electric signals at the property right demarcation point in real time, and when the electric signals at the property right demarcation point are countercurrent, a connecting passage between the grid-connected cabinet 200 and the user load bus is disconnected. The at least one acquisition control unit 400 is connected to the power generation unit 100, and is configured to acquire the electric energy output by the power generation unit 100 in real time. The analysis control module 500 is connected to the at least one acquisition control unit 400 and the reverse-flow prevention relay protection device 300, and is configured to output a control signal according to the electrical signal and the effective power generation amount at the property right boundary point. The acquisition control unit 400 is further configured to control the on/off of the collecting line according to the control signal; the anti-reflux relay protection device 300 is further configured to control the on-off between the grid-connected cabinet 200 and the user load bus according to the control signal.
Specifically, the at least one power generation unit 100 is configured to implement new energy power generation, provide electric energy to a user load, and integrate and collect the electric energy generated by all the power generation units 100 in the grid-connected cabinet 200, and output the electric energy to a user load bus. The property right demarcation point is a demarcation point divided by the maintenance management range of the power supply department and the user electrical equipment according to property right affiliation, and is defined as a connection point of the grid-connected cabinet 200 and the user load bus in the embodiment. The anti-reverse-flow relay protection device 300 monitors the voltage and current at the property right demarcation point. The direction of transmission of electrical energy from the system to the consumer load is defined as the forward direction. When the current is reversely sent to the power grid, the anti-reverse-flow relay protection device 300 disconnects the grid-connected point switch of the grid-connected cabinet 200, and transmits the voltage and the current detected in real time at the property right boundary point to the analysis control module 500.
In this embodiment, the analysis control module 500 is a computer equipped with a SCADA monitoring system. The SCADA monitoring system calculates the magnitude of forward power according to the voltage and current received at the property right boundary point in real time, namely the total amount of electric energy which can be consumed by a user; and calculating the number of the collecting lines of the power generation unit 100 to be input according to the magnitude of the forward power, and ensuring that the total power generation amount of the input collecting lines is less than the forward power of the property right boundary point. At this time, the SCADA monitoring system outputs a control signal to the collection control unit 400, and the collection control unit 400 automatically performs an operation of disconnecting the corresponding collection lines in sequence. Finally, the SCADA monitoring system outputs a control signal to the anti-reverse-flow relay protection device 300 to perform the operation of turning on and off the switch of the grid-connected point. The grid-connected power generation anti-reflux system avoids the phenomenon of reflux caused by residual electric energy output by controlling the total electric energy output by the system to be less than the electric energy required by a user load, and also avoids the condition of energy waste caused by directly disconnecting a grid-connected point switch after the phenomenon of reflux is generated.
Fig. 2 is a schematic diagram of a specific connection of the grid-connected power generation anti-reflux system according to one embodiment of the present invention, in one embodiment, the grid-connected power generation anti-reflux system further includes a communication module 600. The communication module 600 is respectively connected to the analysis control module 500, the at least one collection control unit 400, and the reverse-flow prevention relay protection device 300, and is configured to respectively establish a communication connection between the analysis control module 500 and the at least one collection control unit 400 and a communication connection between the analysis control module 500 and the reverse-flow prevention relay protection device 300. When the reverse-flow prevention relay protection device 300 monitors the property right boundary point in real time and finds that a reverse-flow phenomenon occurs, the reverse-flow prevention relay protection device 300 disconnects the grid-connected point switch of the grid-connected cabinet 200, and transmits the electric signal collected in real time at the property right boundary point to the analysis control module 500 through the communication module 600. The analysis control module 500 calculates the magnitude of the forward power of the title dividing point according to the electrical signal. At this time, the collection control module 400 transmits the monitoring condition of the power generation unit 100 to the analysis control module 500 through the communication module 600. The analysis control module 500 determines which of the power generation units 100 are in the power input state, and obtains the preset power generation amount of the power generation unit 100 in the power input state. The analysis control module 500 determines which power generation units 100 are put in to ensure that the total power output by the system is less than the power required by the user load according to the magnitude of the forward power and the conditions of the power generation units 100, and outputs a control signal to the acquisition control unit 400. And the acquisition control unit 400 controls the corresponding power generation unit 100 to access to the collection path in the grid-connected cabinet according to the control signal. Finally, the analysis control module 500 outputs a control signal to the reverse-flow prevention relay protection device 300 through the communication module 600, and the reverse-flow prevention relay protection device 300 closes the grid-connected point switch of the grid-connected cabinet 200 according to the control signal. The maximum power generation amount of the new energy in the system can be guaranteed to be completely consumed by the user load, and then the new energy power station is put into the new energy power station again, so that the purpose of guaranteeing the consumption level of the new energy by the user is achieved.
In one embodiment, the communication module 600 includes a wired communication module or/and a wireless communication module. The communication module 600 of the grid-connected power generation backflow prevention system may be a wired communication module or a wireless communication module, or may include both the wired communication module and the wireless communication module. If the communication module 600 uses a wired communication module to realize the communication connection between the analysis control module 500 and the collection control unit 400 and the backflow-preventing relay protection device 300, the wired communication module is less interfered, and has strong reliability and confidentiality. If the communication module 600 uses a wireless communication module to realize the communication connection between the analysis control module 500 and the collection control unit 400 and the backflow-preventing relay protection device 300, the wireless communication module is not constrained by a connecting line, and is flexible in networking and good in expandability. If the communication module 600 includes both a wired communication module and a wireless communication module, a more appropriate communication mode can be selected according to the application requirements to implement communication connection.
In one embodiment, the grid-connected power generation backflow prevention system uses an ethernet technology to implement communication connection between the analysis control module 500 and the collection control unit 400 and the backflow prevention relay protection device 300, respectively. The communication connection is realized by adopting the Ethernet technology, the original monitoring network in the transformer substation can be used for communication without adding a communication cable, and the communication network in the transformer substation is the Ethernet, so that the communication mode is more stable and reliable.
In one embodiment, the power generation unit 100 is a photovoltaic power generation unit. The power generation unit 100 can generate new energy electric energy for a user load by using a photovoltaic power generation technology. Photovoltaic power generation has the advantages of sufficient cleanliness, absolute safety, relative universality, reliable long service life, maintenance-free property, resource sufficiency, potential economy and the like, and the new energy power generation technology plays an important role in a long-term energy strategy.
In one embodiment, the grid-connected cabinet 200 includes a grid-connected point switch, which is used to switch on and off a connection path between the grid-connected cabinet and the user load bus. When the reverse-flow prevention relay protection device 300 detects that a reverse-flow phenomenon occurs, the reverse-flow prevention relay protection device 300 disconnects the connection path between the grid-connected cabinet and the user load bus by controlling to disconnect the grid-connected point switch of the grid-connected cabinet 200.
In one embodiment, the at least one trunk line is preset with different priorities. By setting different priorities for each of the trunk lines, the trunk line with the higher priority is preferentially disconnected when determining which power generation units 100 need to be disconnected so that the electric energy generated by the system is within the consumption level of the user load. And then, calculating the effective power generation of the system at the moment, comparing the effective power generation with the real-time power P, and if the effective power generation of the system is still larger than the real-time power P, continuing to disconnect the collecting line with the next higher priority. The priority of the collection line can ensure that the system does not generate confusion when judging which power generation units 100 are disconnected.
In one embodiment, the acquisition control unit 400 comprises a circuit breaker. The analysis control module 500 determines which power generation units 100 are put in to ensure that the total power output by the system is less than the power required by the user load according to the magnitude of the forward power and the conditions of the power generation units 100, and then outputs a control signal to the acquisition control unit 400. And the acquisition control unit 400 controls the on-off of the corresponding collection path of the power generation unit 100 communicated into the grid-connected cabinet according to the control signal to control the on-off of the breaker. The power consumption level of the user load is adapted by reducing the power generation of the power generation unit 100, so that the situation of energy waste caused by directly turning off the grid-connected point switch after a counter-current phenomenon is generated is avoided.
In one embodiment, the collection control unit 400 further includes a line protection measurement and control device, connected to the circuit breaker, for collecting the electric energy output by the power generation unit 100 in real time, and controlling the on/off of the circuit breaker according to the control signal. When a reverse flow phenomenon occurs, the line protection measurement and control device collects the electric energy output condition of the power generation unit 100 and transmits the electric energy output condition to the analysis control module 500, so that the analysis control module 500 can judge the electric energy output condition. The line protection measurement and control device can also receive the control signal output by the analysis control module 500, and controls the on-off of the circuit breaker according to the control signal so as to control the on-off of the collecting line.
In one embodiment, the analysis control module is a computer. The computer can be used for carrying out numerical calculation, such as calculating to obtain the total effective power generation of the system, and carrying out logic calculation, such as judging whether the effective power generation of the system can be completely consumed by the user load at the moment, and the intelligent electronic equipment also has a storage and memory function, and is modern intelligent electronic equipment capable of automatically operating and processing real-time data at a high speed according to a program.
In one embodiment, the analysis control module is a computer equipped with a SCADA monitoring system. A new functional module can be developed on the basis of an original computer provided with SCADA monitoring software of a power transformation plant, and the anti-reverse power relay protection device is matched, so that the anti-reverse flow is achieved, and the consumption capacity of a user on new energy power generation is improved.
The utility model also provides a grid-connected power generation anti-reflux method is applied to grid-connected power generation anti-reflux system. The grid-connected power generation anti-reflux system comprises at least one power generation unit 100 and a grid-connected cabinet 200, wherein the at least one power generation unit is connected with a user load bus through the grid-connected cabinet, a connecting passage of the at least one power generation unit connected into the grid-connected cabinet forms at least one collecting line, and a connecting point of the grid-connected cabinet connected into the user load bus is a property right demarcation point. Fig. 3 is a flowchart of a grid-connected power generation backflow prevention method according to an embodiment of the present invention, and in one embodiment, the method includes the following steps S100 to S500.
S100: and acquiring and monitoring the electric signals at the property right demarcation points in real time, and disconnecting a connecting passage between the grid-connected cabinet and the user load bus when the electric signals at the property right demarcation points have counter flow.
S200: and monitoring the working state of the at least one collecting line to obtain the effective power generation amount of the system.
S300: comparing the effective power generation with real-time power at the title demarcation point.
S400: and when the effective generating capacity is smaller than the real-time power at the property right demarcation point, a connecting passage between the grid-connected cabinet and the user load bus is conducted.
S500: and when the effective power generation is larger than the real-time power at the property right boundary point, disconnecting one passage of the collection line until the effective power generation is smaller than the real-time power at the property right boundary point.
Specifically, build in spontaneous new forms of energy power station of using forbidden surplus electricity on the internet of oneself the utility model discloses a grid-connected electricity generation prevents system against current, including at least a power generation unit 100, the cabinet 200 that is incorporated into the power networks, prevent against current relay protection device 300, an at least sampling control unit 400 and analysis control module 500. Wherein, in order to better explain the specific steps of the grid-connected power generation anti-reflux method, in this embodiment, the analysis control module 500 is a computer equipped with an SCADA monitoring system, the power generation units 100 in the system have five, every power generation unit 100 collects to the connecting passage of the grid-connected cabinet constitutes a collection line, the five collection lines are shown as the photovoltaic collection lines 1 to 5 in fig. 2, the collection control unit 400 is constituted by a line protection measurement and control device and a circuit breaker, but the above description can not be understood as the limitation of the protection scope of the present invention.
Under the normal operation condition of the system, the user load preferentially consumes the new energy electric energy generated by the system, when the new energy electric energy generated by the system is completely consumed by the user load, the user load additionally obtains the electric energy from the power grid, at this time, the electric energy P acquired by the anti-countercurrent relay protection device 300 at the property right boundary point is the electric energy obtained from the power grid, and the direction is positive (the direction of the electric energy from the system to the user is defined as the positive direction).
And when the user load is reduced, on the basis of preferentially consuming the new energy power generation amount, reducing the power P acquired from the power grid. When the user load is reduced to the state that the electric quantity required by the user load is completely provided by the new energy power generation and the electric quantity generated by the new energy is surplus, the surplus electric quantity is returned to the power grid through the property right boundary point, at the moment, reverse current appears and the power P of the property right boundary point is a negative value. When the reverse-flow-prevention relay protection device 300 detects that a reverse flow occurs at the property right boundary point, the reverse-flow-prevention relay protection device 300 disconnects the grid-connected point switch at the grid-connected cabinet 200, namely, disconnects the connection path between the grid-connected cabinet 200 and the user load bus. After the grid-connected point switch is turned off, the electric energy required by the user load is obtained from the power grid again, at this time, the reverse-flow prevention relay protection device 300 can acquire a larger positive real-time power P at the property right boundary point, and the real-time power P at this time is the electric energy level which can be accommodated by the user load. The anti-reflux protection device 300 transmits the real-time power P to the SCADA monitoring system.
The SCADA monitoring system acquires the condition that the acquisition control unit 400 acquires the electric energy of the power generation unit 100 in real time and acquires the total effective generated energy of the system. And the SCADA monitoring system compares the effective generated energy with the real-time power P at the property right demarcation point and judges whether the effective generated energy of the system can be completely consumed by the user load at the moment. If the effective generated energy is smaller than the real-time power P at the property right demarcation point, it is indicated that the electric energy generated by the system is within the consumption level of the user load at the moment, and the phenomenon of backflow caused by residual electric quantity does not occur, at the moment, the SCADA monitoring system outputs a control signal to the backflow-preventing relay protection device 300, and the backflow-preventing relay protection device 300 closes a grid-connected point switch at the grid-connected cabinet 200 according to the control signal, that is, a connecting path between the grid-connected cabinet and the user load bus is conducted. If the effective generated energy is larger than the real-time power P at the property right demarcation point, it is indicated that the electric energy generated by the system is larger than the consumption level of the user load, and if the grid-connected point switch is closed, the phenomenon that the electric quantity of the new energy output by the system is remained to cause reverse flow still occurs, and a new energy circuit generated by the system needs to be reduced. The SCADA monitoring system judges which power generation units 100 need to be disconnected according to the real-time power P at the property right demarcation point and the preset power generation amount of each power generation unit 100 in the input state, so that the electric energy generated by the system is within the consumption level of the user load, and transmits a control signal to the acquisition control unit 400. The collection control unit 400 disconnects one of the collection lines according to the control signal until the effective power generation of the system is less than the real-time power P at the property right demarcation point. The total electric energy output by the system is controlled within the level capable of being accommodated by the user load, so that the phenomenon of countercurrent caused by surplus electric energy output is avoided, and the condition of energy waste caused by directly disconnecting a grid-connected point switch after the phenomenon of countercurrent is generated is also avoided.
Fig. 4 is a flowchart of a method for monitoring an operating status of a trunk line according to an embodiment of the present invention, where the monitoring of the operating status of the at least one trunk line includes steps S210 to S220.
S210: and monitoring the at least one collecting line in real time, and judging whether the at least one collecting line is in an electric energy generating state.
S220: and acquiring the preset power generation amount of the collecting line in the electric energy output state.
Specifically, after the grid-connected point switch is turned off, the acquisition control unit 400 transmits the condition of the power generation unit 100 acquired in real time to the SCADA monitoring system. The SCADA monitoring system determines whether each of the power generation units 100 is in an electric energy output state and whether each of the collection lines is in an input state. Screening all the collection lines in the electric energy output state, acquiring preset power generation capacity of all the collection lines in the electric energy output state so that the SCADA monitoring system can acquire the total effective power generation capacity of the system, and judging which power generation units 100 need to be disconnected according to the real-time power P at the property right dividing point and the preset power generation capacity of each power generation unit 100 in the input state so that the electric energy generated by the system is within the consumption level of the user load.
In one embodiment, the effective power generation of the system is the sum of the preset power generation of each of the plurality of collector lines in the power generation state. Calculating the maximum generating capacity Ps of the collecting line in the switching state, defining the maximum generating capacity Ps as the effective generating capacity of the system, and defining Ps as the sum of the maximum generating capacities of all the collecting lines of the breaker in the on-position statePs=ΣPi. Pi is a preset maximum power generation fixed value of each collecting line in the closed state. For example, the system has 5 collecting lines in total, and when the SCADA monitoring system detects that the 1 st, 2 nd and 4 th collecting lines are in an on-position state, the maximum power generation amount of the new energy of the system at the moment is Ps=P1+P2+P4。
In one embodiment, before disconnecting the path of one of the trunk lines, the method further comprises the step of presetting different priorities for the at least one trunk line; when the passage of one of the trunk lines is disconnected, the trunk line with high priority is disconnected preferentially. The SCADA monitoring system sets different priorities for each collection line in advance. And preferentially disconnecting the collecting line with high priority when judging which power generation units 100 need to be disconnected so that the electric energy generated by the system is within the consumption level of the user load, calculating the effective power generation amount of the system at the moment, comparing the effective power generation amount with the real-time power P, and if the effective power generation amount of the system is still greater than the real-time power P, continuing to disconnect the collecting line with high priority. And circulating the steps until the effective power generation amount of the system is smaller than the real-time power P, namely indicating that the electric energy generated by the system is within the consumption level of the user load at the moment, and if a grid-connected point switch is closed, avoiding the phenomenon of backflow caused by residual electric quantity.
The SCADA monitoring system can also set the total number of the collecting lines of the system, adjust the voltage and current transformation ratio of each line to complete the setting of system parameters, set the maximum power generation amount Pi of each collecting line to complete the setting of the power generation amount of the collecting lines and set the priority of each collecting line (the priority of each collecting line cannot be set to be the same) to complete the setting of the switching priority of the collecting lines. In addition, the SCADA monitoring system can also display a fixed value, and is used for displaying the fixed value (which cannot be set and changed and is mainly used for checking and verifying); constant value printing for printing a constant value sheet; displaying the property right demarcation point Ps, and displaying real-time sampling data of the property right demarcation point; the collection line switching remote control point association is used for associating the corresponding number with the collection line protection measurement and control device remote control measurement point, so that the remote control operation can be logically executed; a report display for displaying real-time and historical event reports; report printing for printing historical event reports; and clearing the record for clearing the history report.
The utility model also provides a computer equipment, including memory and treater, the memory storage has computer program, a serial communication port, the treater carries out realize any one of above-mentioned embodiment during computer program the step of grid-connected power generation anti-reflux method.
The utility model also provides a computer readable storage medium, its storage has the computer program, its characterized in that, the computer program realizes the step of the grid-connected power generation anti-reflux method of any one of the above-mentioned embodiments when being executed by the treater.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.