Distributed Photovoltaic Voltage Optimization Strategy and Its Control Method Based on Cloud-Cloud Collaboration

Abstract

Distributed photovoltaic voltage optimization strategy and its control method based on cloud-cloud collaboration, including: distributed photovoltaic centralized control cloud master station, distribution automation master station DMS, distributed photovoltaic monitoring module, cloud-cloud interaction component, 10kV line switch information acquisition component of distribution automation master station DMS, and consumption strategy calculation control and operation component of distribution automation master station DMS; applying this technical solution can solve the existing problems that distributed photovoltaics connected to the centralized control system only provide active power, do not provide reactive power, and the active power is uncontrollable, and provide a dispatching method for the power grid with higher efficiency and lower line losses.

Description

Technical Field

[0001] The present invention relates to the technical field of optimal scheduling control for distributed power sources and distributed photovoltaic access on smart grid lines, and particularly to a distributed photovoltaic voltage optimization strategy and its control method based on cloud-cloud collaboration. Background Art

[0002] With the rapid development of distributed photovoltaic power sources, it will inevitably affect the safe and stable operation of the power grid. Relying solely on manual control has become difficult to meet the needs of power grid development. Distributed photovoltaics connected to the centralized control system cannot effectively solve a series of problems brought about by the need for coordinated regulation of energy generation and power grid transmission, such as voltage over-limit, curtailment of light and electricity. Considering the current situation of distributed photovoltaic construction in the pilot areas, effective measures must be taken to meet the needs of future coordinated regulation of multiple energy sources. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a distributed photovoltaic voltage optimization strategy and its control method based on cloud-cloud collaboration, to solve the existing problems that distributed photovoltaics connected to the centralized control system only provide active power, do not provide reactive power, and the active power is uncontrollable, and to provide a more efficient and lower line loss scheduling method for the power grid.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions: The distributed photovoltaic voltage optimization strategy based on cloud-cloud collaboration includes: a distributed photovoltaic centralized control cloud master station, a distribution automation master station DMS, a distributed photovoltaic monitoring module, a cloud-cloud interaction component, a 10kV line switch information acquisition component of the distribution automation master station DMS, and a consumption strategy calculation control and operation component of the distribution automation master station DMS;

[0005] The distributed photovoltaic centralized control cloud master station is an information system deployed in the cloud, serving the distributed power source access control system of the distribution automation system above, collecting information from each distributed photovoltaic monitoring terminal below, and realizing the management and control of distributed power sources within its jurisdiction;

[0006] The distributed photovoltaic monitoring module is used to summarize and display the distributed photovoltaic information accessed by the cloud-cloud interaction method to the distribution automation master station DMS, and is used to detect and judge whether the line needs to be adjusted;

[0007] The cloud-cloud interaction component is used for data interaction between the distributed photovoltaic centralized control cloud and the distribution automation master station DMS, adopts the power telecontrol 104 protocol, collects the operation data of the distributed photovoltaic sub-stations connected to the centralized control cloud master station, and issues control setting values and control instructions;

[0008] The 10kV line switch information acquisition component of the distribution automation master station DMS is used to collect information of pole-mounted switches, ring network switches, disconnecting switches on the line where the distributed photovoltaic site is located, and the 10kV switches of the main transformers associated with this line;

[0009] The consumption strategy calculation control and operation component of the distribution automation master station DMS calculates the control quantities required by each power station based on the collected distributed power station information and the information of the line where the photovoltaic power station is located, and issues them to the distributed photovoltaic centralized control cloud master station through the cloud-cloud interaction component, which distributes the instructions and orders their execution.

[0010] In a preferred embodiment, the functions of the distributed photovoltaic centralized control cloud master station include: distributed power generation monitoring system, distributed power station equipment control system, distributed power station data management system, distributed power source power control system, electric energy metering system of distributed power generation system, distributed power generation power quality monitoring system, and distributed power station communication management system.

[0011] The present invention also provides a control method for the distributed photovoltaic voltage optimization strategy based on cloud-cloud collaboration. The above-mentioned distributed photovoltaic voltage optimization strategy based on cloud-cloud collaboration is adopted, including the following steps:

[0012] Step S1: Through the cloud-cloud interaction component, collect the real-time operating conditions and active / reactive adjustable capabilities of the photovoltaic power station; through the 10kV line switch information acquisition component, collect the three-remote switch on the 10kV line where the photovoltaic power station is located, and the active power, reactive power, voltage, and current information on the 10kV switch of the main transformer connected to the line;

[0013] Step S2: Send the collected data and 10kV line topology data to the distributed photovoltaic monitoring module, which judges the over-limit nodes of the 10kV line and sends the line parameters to be set to the consumption strategy calculation control and operation component of the distribution automation master station DMS;

[0014] Step S3: The consumption strategy calculation control and operation component of the distribution automation master station DMS calculates the values that need to be set for the line and sends the values to the cloud-cloud interaction component;

[0015] Step S4: The cloud-cloud interaction component of the distribution automation master station DMS sends the active and reactive power adjustment amounts of each distributed photovoltaic power station that need to be adjusted to the centralized control cloud master station, and receives the control situation and results feedback by the centralized control cloud master station;

[0016] Step S5: The distributed photovoltaic monitoring module monitors the operating conditions of each photovoltaic power station in real time.

[0017] In a preferred embodiment, in the step S1, the collected photovoltaic and switch data and the line topology data are traversed and transformed.

[0018] In a preferred embodiment, in the step S2, the distributed photovoltaic monitoring module monitors the voltage value deviation of each node according to the difference between the real-time voltage value of the node and the upper and lower voltage threshold values, and determines whether the real-time voltage value exceeds the upper threshold value or the lower threshold value; if the node has an over-limit situation, the over-limit node number and the over-limit type are recorded. After the monitoring of each node in this round is completed, the over-line node numbers are uniformly sent to the power distribution automation master station DMS consumption strategy calculation control and operation component.

[0019] In a preferred embodiment, in the step S3, after receiving the over-limit information, the power distribution automation master station DMS consumption strategy calculation control and operation component first classifies the over-limit types, and divides the over-limit node information into two parts: the nodes that exceed the upper limit and the nodes that exceed the lower limit; for the nodes that exceed the upper limit, the voltage over-limit situation is eliminated by adjusting the reactive power of the photovoltaic power station at the over-limit node; assuming that the voltage of node m exceeds the upper limit, the reactive power adjustment amount at node m will be calculated according to the following formula:

[0020]

[0021] In the formula, △Q DG.m represents the reactive power adjustment amount of the distributed power source at node m; U N represents the rated voltage of the 10kV substation bus; U m represents the measured voltage at node m; represents the total reactive impedance from node 0 to node i; represents the upper limit value of the voltage deviation.

[0022] In a preferred embodiment, in the step S3, after receiving the over-limit information, for the nodes that exceed the lower limit, the voltage is raised by adjusting the active power of the photovoltaic power station at the over-limit node; assuming that the voltage of node m exceeds the lower limit, the active power adjustment amount at node m will be calculated according to the following formula:

[0023]

[0024] In the formula, △P DG.m represents the active power adjustment amount of the distributed power source at node m; represents the total resistance from node 0 to node i.

[0025] In a preferred embodiment, in the step S4, after calculating the active and reactive power adjustment amounts of the voltage over-limit nodes, the power distribution automation master station DMS consumption strategy calculation control and operation component synchronizes the adjustment amounts of the photovoltaic power stations that need to be adjusted and set to the distributed photovoltaic centralized control cloud master station through the cloud-cloud interaction component.

[0026] In a preferred embodiment, in the step S5, after the adjustment instruction is sent to the distributed photovoltaic centralized control cloud master station, the distributed photovoltaic monitoring module monitors the operation conditions of each photovoltaic power station that needs to be adjusted and set in real time in this round.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The method for connecting part of the distributed photovoltaic to the distribution automation master station through the centralized control cloud master station described in the present invention realizes the data acquisition of the existing distributed photovoltaic and improves the perception ability of the active distribution network.

[0029] 2. The distributed photovoltaic voltage over-limit control method described in the present invention realizes the control and adjustment functions of the existing non-directly collected distributed photovoltaic and improves the adjustment ability of the distribution automation system for distributed power sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of a 10kV line of a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present invention will be further described below in conjunction with the drawings and embodiments.

[0032] It should be noted that the following detailed description is exemplary and is intended to provide further description of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0034] The present invention provides a distributed photovoltaic voltage optimization strategy and its control method based on cloud-cloud collaboration, including the following steps:

[0035] Step S1: Through the cloud-cloud interaction component, collect the real-time operating conditions and active / reactive power adjustable capabilities of the photovoltaic power station; through the 10kV line switch information collection component, collect the active power, reactive power, voltage and current information of the three-remote switch on the 10kV line where the photovoltaic power station is located and the 10kV switch of the main transformer connected to the line.

[0036] Step S2: Send the collected data and the 10 kV line topology data to the distributed PV monitoring module, which judges the over-limit nodes of the 10 kV line and sends the line parameters to be set to the DMS consumption strategy calculation control and operation component;

[0037] Step S3: The DMS consumption strategy calculation control and operation component calculates the values to be set for the line and sends the values to the cloud-cloud interaction component;

[0038] Step S4: The DMS cloud-cloud interaction component sends the active and reactive power adjustment amounts of each distributed PV power station to be adjusted to the centralized control cloud master station and receives the control status and results feedback by the centralized control cloud master station;

[0039] Step S5: The distributed PV monitoring module monitors the operation status of each PV power station in real time;

[0040] In the said Step S1, traverse and transform the collected PV, switch data and line topology data to form the following Figure 1 as shown;

[0041] In the figure, 0, 1, 2, …, i, j, k, … n are node numbers, node 0 represents the busbar, DG is connected at point j, and i and k are the adjacent upstream and downstream nodes without DG access respectively;

[0042] In the said Step S2, the distributed PV monitoring module monitors the voltage value deviation of each node according to the difference between the real-time voltage value of the node and the voltage upper and lower limit thresholds, and determines whether the real-time voltage value exceeds the upper limit threshold or the lower limit threshold. If the node has an over-limit situation, record the over-limit node number and over-limit type. After the monitoring of each node in this round is completed, send the over-line node numbers to the DMS consumption strategy calculation control and operation component uniformly;

[0043] In the said Step S3, after receiving the over-limit information, the DMS consumption strategy calculation control and operation component first classifies the over-limit types, and divides the over-limit node information into two parts of node sets of over upper limit and over lower limit. For the nodes with over upper limit, eliminate the voltage over-limit situation by adjusting the reactive power of the PV power station at the over-limit node; taking Figure 1 point m in it as an example, assuming that the voltage of node m exceeds the upper limit, the reactive power adjustment amount at node m will be calculated according to the following formula:

[0044]

[0045] In the formula:

[0046] △Q DG.m represents the reactive power adjustment amount of the distributed power source at node m;

[0047] U NIt is expressed as the rated voltage of the 10 kV substation busbar;

[0048] U m represents Figure 1 the measured voltage at node m in;

[0049] It is expressed as the total accumulated reactance from node 0 to node i;

[0050] It is expressed as the upper limit value of voltage deviation;

[0051] In the said step S3, after the DMS accommodation strategy calculation control and operation component receives the out-of-limit information, for the nodes with voltage lower than the limit, the active power of the photovoltaic power stations at the out-of-limit nodes is adjusted to raise the voltage; taking Figure 1 node m in as an example, assuming that the voltage at node m is lower than the limit, the active power adjustment amount at node m will be calculated according to the following formula:

[0052]

[0053] In the formula:

[0054] △P DG.m represents the active power adjustment amount of the distributed power source at node m;

[0055] U N It is expressed as the rated voltage of the 10 kV substation busbar;

[0056] U m represents Figure 1 the measured voltage at node m in;

[0057] It is expressed as the total accumulated resistance from node 0 to node i;

[0058] It is expressed as the upper limit value of voltage deviation;

[0059] If the voltage lower than the limit situation is not eliminated after this active power adjustment, reactive power adjustment will be carried out according to the content described in step 3;

[0060] In the said step S4, after the DMS accommodation strategy calculation control and operation component calculates the active and reactive power adjustment amounts of the voltage out-of-limit nodes, the adjustment amounts of the photovoltaic power stations that need to be adjusted and set are synchronized to the distributed photovoltaic centralized control cloud master station through the cloud-cloud interaction component;

[0061] In the said step S5, after the adjustment instruction is sent to the distributed photovoltaic centralized control cloud master station, the distributed photovoltaic monitoring module monitors the operation conditions of each photovoltaic power station that needs to be adjusted and set in this round in real time;

[0062] The above are the preferred embodiments of the present invention. All changes made according to the technical solution of the present invention, as long as the functions and effects produced do not exceed the scope of the technical solution of the present invention, fall within the protection scope of the present invention.

Claims

1. Control method for distributed photovoltaic voltage optimization strategy based on cloud-cloud collaboration, characterized in that Including: Distributed PV centralized control cloud master station, distribution automation master station DMS, distributed PV monitoring module, cloud-cloud interaction component, 10kV line switch information acquisition component of distribution automation master station DMS, consumption strategy calculation control and operation component of distribution automation master station DMS; The distributed PV centralized control cloud master station is an information system deployed in the cloud, serving the distributed power access control system of distribution automation upward, collecting information from each distributed PV monitoring terminal downward, and realizing the management and control of distributed power within its jurisdiction; The distributed PV monitoring module is used to summarize and display the distributed PV information accessed by the cloud-cloud interaction method to the distribution automation master station DMS, and is used to detect and judge whether the line needs to be adjusted; The cloud-cloud interaction component is used for data interaction between the distributed PV centralized control cloud master station and the distribution automation master station DMS, adopting the power telecontrol 104 protocol, collecting the operation data of the distributed PV substation connected to the centralized control cloud master station, and sending down the control setting value and control instruction; The 10kV line switch information acquisition component of the distribution automation master station DMS is used to collect information of pole-mounted switches, ring network switches, disconnecting switches on the line where the distributed PV site is located, and the 10kV switch of the main transformer associated with this line; The consumption strategy calculation control and operation component of the distribution automation master station DMS calculates the control quantity required by each power station according to the collected distributed power station information and the information of the line where the PV power station is located, and sends it down to the distributed PV centralized control cloud master station through the cloud-cloud interaction component, and the master station distributes the instructions and issues the instructions for execution; Including the following steps: S1: Through the cloud-cloud interaction component, collect the real-time operation conditions and active / reactive power adjustable capabilities of the PV power station; Through the 10kV line switch information acquisition component of the distribution automation master station DMS, collect the active power, reactive power, voltage and current information of the three-remote switch on the 10kV line where the PV power station is located and the 10kV switch of the main transformer connected to the line; S2: Send the collected data and 10kV line topology data to the distributed PV monitoring module, which judges the over-limit nodes of the 10kV line, and sends the line parameters to be set to the consumption strategy calculation control and operation component of the distribution automation master station DMS; S3: The consumption strategy calculation control and operation component of the distribution automation master station DMS calculates the value that needs to be set for the line and sends the value to the cloud-cloud interaction component; S4: The cloud-cloud interaction component sends the active and reactive power adjustment amounts of each distributed PV power station that needs to be adjusted to the distributed PV centralized control cloud master station, and receives the control situation and results feedback by the distributed PV centralized control cloud master station; S5: The distributed PV monitoring module monitors the operation conditions of each PV power station in real time; In S3, after receiving the over-limit information, the consumption strategy calculation control and operation component of the distribution automation master station DMS first classifies the over-limit types, and divides the over-limit node information into two node sets: over upper limit and over lower limit; For the nodes with over upper limit, eliminate the voltage over-limit situation by adjusting the reactive power of the PV power station at the over-limit node; Assume that the voltage at node m exceeds the upper limit, and the reactive power adjustment amount at node m will be calculated according to the following formula: where, △Q DG.m is the reactive power regulation amount of the distributed power source at node m; U N is the rated voltage of the 10kV substation bus; U m is the measured voltage at node m; is the total accumulated reactance value from node 0 to node i; is the upper limit value of the voltage deviation.

2. The control method according to claim 1, wherein: The functions of the distributed PV centralized control cloud master station include: distributed power generation monitoring system, distributed power station equipment control system, distributed power station data management system, distributed power source power control system, power metering system of distributed power generation system, power quality monitoring system of distributed power generation, and distributed power station communication management system.

3. The control method according to claim 1, wherein In the step S1, the collected PV and switch data are traversed and transformed with the line topology data.

4. The control method according to claim 1, characterized in that In the step S2, the distributed PV monitoring module monitors the voltage value deviation of each node according to the difference between the real-time voltage value of the node and the upper and lower voltage threshold values, and determines whether the real-time voltage value exceeds the upper threshold value or the lower threshold value; if the node has an over-limit situation, the over-limit node number and over-limit type are recorded. After the monitoring of each node in this round is completed, the over-line node numbers are sent to the distribution automation master station DMS consumption strategy calculation control and operation component uniformly.

5. The control method according to claim 1, wherein In the step S3, after receiving the over-limit information, for the nodes with voltage lower than the limit, the distribution automation master station DMS consumption strategy calculation control and operation component raises the voltage by adjusting the active power of the PV power station of the over-limit node; assuming that the voltage of node m is lower than the limit, the active power adjustment amount at node m will be calculated according to the following formula: where, △P DG.m represents the active power regulation amount of the distributed power source at node m; represents the total resistance accumulation value from node 0 to node i.

6. The control method according to claim 1, wherein In the step S4, after the distribution automation master station DMS consumption strategy calculation control and operation component calculates the active and reactive power adjustment amounts of the voltage over-limit nodes, the PV power station adjustment amounts that need to be adjusted and set are synchronized to the distributed PV centralized control cloud master station through the cloud-cloud interaction component.

7. The control method according to claim 1, wherein In the step S5, after the adjustment instruction is sent to the distributed PV centralized control cloud master station, the distributed PV monitoring module monitors the operation status of each PV power station that needs to be adjusted and set in this round in real time.

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