Area voltage out-of-limit autonomous system and method based on active-reactive comprehensive control

Abstract

The invention provides a transformer area voltage out-of-limit autonomous system based on active-reactive comprehensive control, which comprises a group control and group scheduling master station, a power distribution intelligent gateway, a protocol converter and an inverter, and is characterized in that the group control and group scheduling master station communicates with the power distribution intelligent gateway in a 4G network mode, the power distribution intelligent gateway receives an instruction of the group control and group scheduling master station, and the protocol converter is connected with the inverter. The intelligent power distribution gateway is used for receiving operation information of the inverters and transmitting remote signaling and telemetering information to the group control and group dispatching master station at the same time, the intelligent power distribution gateway is communicated with the protocol converter through a broadband power line carrier HPLC, the intelligent power distribution gateway receives the operation information of the inverters and can decompose received active and reactive instructions of the intelligent power distribution gateway to the inverters at the same time, and the inverters are connected with the protocol converter. And the protocol converter communicates with the inverters through an RS-485 protocol, and the protocol converter is used for forwarding an adjustment instruction issued by the intelligent power distribution gateway to each inverter, collecting inverter data and uploading an execution result to the intelligent power distribution gateway at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of over-limit autonomous voltage in a transformer substation, and in particular to an over-limit autonomous voltage system and method for a transformer substation based on active-reactive integrated control. Background Art

[0002] The surge in the installed capacity of distributed power sources has brought difficulties and challenges to the safe and reliable operation of traditional distribution networks. In some areas with a high proportion of distributed photovoltaic installed capacity, the problems of grid absorption balance and power supply quality have become increasingly prominent. The blowout, small-capacity, decentralized distributed power access has brought challenges to the safe, reliable and stable operation of Yunnan's asynchronous "five highs" power grid. In particular, the penetration rate of distributed photovoltaics in some local areas is as high as 200%, which has become a problem that the power grid urgently needs to solve.

[0003] The distribution network is mainly based on residential electricity load, which will cause source-load mismatch problems, greatly increasing the possibility of voltage over-limit. During the day, the photovoltaic grid-connected power is high while the residential load is low; at night, the residential electricity consumption is at its peak while the photovoltaic power generation power approaches zero. When the proportion of distributed photovoltaics connected is too high, during the day when the sunlight is sufficient and the load is low, excess power will be generated on the distribution network side, which will lead to overvoltage problems in the distribution network; and the source-load reversal at night cannot improve the inherent low voltage problem of the low-voltage distribution network. Therefore, the problem of the distribution network voltage over-limit has become increasingly prominent after a high proportion of distributed photovoltaics are connected.

[0004] In order to meet the regulation and control needs of the power grid, it is necessary to install protocol converters in substations with a large number of new energy sources connected. The protocol converter communicates with the new energy inverter through 485 and communicates with the distribution intelligent gateway through HPLC (power carrier). The group control and group dispatching master station can first issue instructions to the distribution intelligent gateway, and the distribution intelligent gateway can further distribute instructions to each inverter. However, the instructions of the group control and group dispatching master station are not real-time, and it is impossible to monitor the voltage over-limit problem of all substations in real time. Therefore, the voltage over-limit problem of the substation needs to be solved locally through the distribution intelligent gateway. The present invention proposes a local autonomous method for substation voltage over-limit based on active-reactive comprehensive control. Summary of the invention

[0005] The object of the present invention is to provide an autonomous system and method for voltage over-limit control in a substation area based on active-reactive integrated control, so as to solve the problems raised in the above-mentioned background technology.

[0006] The present invention is achieved through the following technical solutions:

[0007] On the one hand, the present invention also provides an autonomous system for voltage over-limit in a substation based on active-reactive integrated control, including a group control and group dispatching master station, a distribution intelligent gateway, a protocol converter and an inverter. The group control and group dispatching master station communicate with the distribution intelligent gateway through a 4G network. The distribution intelligent gateway receives instructions from the group control and group dispatching master station, and sends telesignaling and telemetry information to the group control and group dispatching master station. The distribution intelligent gateway communicates with the protocol converter through a broadband power line carrier HPLC. The distribution intelligent gateway receives the operating information of the inverter, and can decompose the received active and reactive instructions of the distribution intelligent gateway to each inverter. The protocol converter communicates with the inverter through the RS-485 protocol. The protocol converter is used to forward the adjustment instructions issued by the distribution intelligent gateway to each inverter, and collect inverter data and execution results and send them to the distribution intelligent gateway.

[0008] Specifically, the power distribution intelligent gateway includes a metering module, a strategy module, a 104 protocol module, a 4G module, a 645 protocol module, and an HPLC module. The metering module is used to collect the grid connection points of the voltage transformer PT and the current transformer CT, and output the results to the strategy module. The strategy module is used to generate adjustment instructions. The 645 protocol module receives the adjustment instructions of the strategy module and sends them to the inverter through the HPLC module. At the same time, the inverter sends the inverter information to the 645 protocol module through the HPLC module, and the group control and group adjustment master station sends it to the strategy module through the 4G module through the 104 protocol module.

[0009] Specifically, the strategy module is also used to send the station area information to the protocol module 104.

[0010] On the other hand, the present invention also provides a voltage over-limit autonomous method for a substation based on active-reactive integrated control, the method being applied to the system as claimed in claims 1 to 3, the method comprising the following steps:

[0011] S1: Calculate the operation data of the substation area, and receive the active power P of the substation area calculated by the metering module through the strategy module 台 , reactive power Q 台 , voltage U 台 And the sensitivity coefficient K of active power to grid connection point voltage 有 ;

[0012] S2: Set the voltage over-limit value, and set the starting voltage over-limit adjustment criteria according to the voltage over-limit value, as follows:

[0013] When U 台 >U setH When U 台 <U setL When it exceeds the lower limit, the U setHIndicates that the voltage is below the limit value, the U setL Indicates that the voltage is below the limit value;

[0014] S3: When U 台 >U setH When the charging time is up, the energy storage regulation instruction that needs to be charged is issued;

[0015] S4: After the energy storage regulation instruction is issued, it is delayed to re-determine whether the voltage exceeds the limit. If it does not exceed the limit, the local regulation ends. If the voltage still exceeds the limit, the output of reactive power and active power is reduced, and a power regulation instruction for each inverter is generated;

[0016] S5: When U 台 <U setL , issue energy storage regulation instructions that need to be discharged;

[0017] S6: After the energy storage regulation instruction is issued, it is delayed to re-determine whether the voltage exceeds the limit. If it does not exceed the limit, the local regulation ends. If the voltage still exceeds the limit, the output of reactive power and active power is increased, and a power regulation instruction is generated for each inverter.

[0018] Specifically, the specific process of step S4 includes:

[0019] S41: Reduce reactive power output: When issuing reactive power instructions, it is necessary to allocate reactive power instructions to each inverter. The greater the inverter output, the greater the reactive power reduction responsibility it bears;

[0020] The calculation formula for the reactive power reduction of each inverter is:

[0021]

[0022] Among them, Q 当前i is the current actual reactive power of the i-th inverter, ∑Q 当前i is the sum of the current reactive power of all inverters in the area, ΔQ 减 is the total amount of reactive power that needs to be reduced, ΔQ 减i is the reactive power reduced by the i-th inverter;

[0023] Then the reactive power command of each inverter is Q i =Q 当前i +ΔQ 减i , Q i is the reactive power instruction of the i-th inverter;

[0024] S42: Reduce the output of active power: When issuing the active power adjustment command, it is necessary to allocate the active power command of each inverter, and set the greater the output of each inverter, the greater the responsibility of reducing the active power;

[0025] The calculation formula for reducing the active power of each inverter is:

[0026]

[0027] Among them, P 当前i is the current active power of the i-th inverter, ∑P 当前i is the sum of the actual active power of all inverters in the area, ΔP 减 is the total amount of active power that needs to be reduced, ΔP 减i The active power reduced by the i-th inverter;

[0028] Then the active power command of each inverter is P i =P 当前i -ΔP 减i , P i is the active power command of the i-th inverter.

[0029] Specifically, the specific process of step S6 includes:

[0030] S61: increasing the output of active power: when issuing active power instructions, it is necessary to allocate active power instructions for each inverter, and the greater the output of each inverter, the smaller the responsibility for increasing active power;

[0031] The calculation formula for increasing the active power of each inverter is:

[0032]

[0033] Among them, P 当前i is the current active power of each inverter, ∑P 当前i is the sum of the active power generated by all inverters in the area, ΔP 增 is the total amount of active power that needs to be increased, ΔP 增i The active power adjusted up by the i-th inverter;

[0034] Then the active power instruction of each inverter is P i =P 当前i +ΔP 增i , P i is the active power instruction of the i-th inverter;

[0035] S62: Increase the output of active power: when issuing reactive power instructions, it is necessary to allocate reactive power instructions to each inverter, and the greater the inverter output, the smaller the responsibility for increasing reactive power;

[0036] The calculation formula for the reactive power increase of each inverter is:

[0037]

[0038] Among them, Q 当前i is the current reactive power of each inverter, ∑Q 当前i is the sum of the reactive power generated by all inverters in the area, ΔQ 增 is the total amount of reactive power that needs to be added, ΔQ 增i is the reactive power adjusted up by the i-th inverter;

[0039] Then the reactive power command of each inverter is Q i =Q 当前i +ΔQ 增i , Q i is the reactive power instruction of the i-th inverter.

[0040] Specifically, the method further includes, when there is an AGC dispatching instruction or an AVC dispatching instruction, considering the coordination and cooperation between the energy storage adjustment instruction and the AGC dispatching instruction or the AGC dispatching instruction:

[0041] When the voltage exceeds the limit in the substation, the local strategy takes priority, the power command of the inverter is completely generated locally, and the AGC dispatch command and AGC dispatch command are blocked;

[0042] When the voltage in the substation exceeds the limit, it needs to be redistributed in accordance with the AGC dispatching instructions and the AGC dispatching instructions. The distribution principle is to distribute the regulated power according to the capacity ratio:

[0043] The active power that needs to be adjusted by the AGC dispatch instruction is: △P agc =P agc -∑P 实发i ;

[0044] The reactive power that needs to be adjusted by the AGC dispatch instruction is: △Q avc =Q aVc -∑Q 实发i ;

[0045] Among them, △P agc is the active power that needs to be adjusted by the AGC dispatch instruction, P agc is the AGC scheduling instruction, ∑P 实发i is the actual active power generated by all inverters, △Q avc is the reactive power that needs to be adjusted by the AGC dispatch instruction, Q aVc is the AGC scheduling instruction, ∑Q 实发i is the actual reactive power generated by all inverters;

[0046] When there is an AGC scheduling instruction or an AVC scheduling instruction, the regulated power of each inverter is:

[0047]

[0048] Among them, △P i is the regulated active power of the i-th inverter when there is an AGC dispatch instruction or an AVC dispatch instruction, P 额定i is the rated active power of each inverter, △Q i is the regulated reactive power of the i-th inverter when there is an AGC dispatch instruction or an AVC dispatch instruction, Q 额定i is the rated reactive power of each inverter;

[0049] Then the power command of each inverter is: P i =P 实发i +△P i , Q i =Q 实发i +△Q i ;

[0050] Among them, P i is the active power command of each inverter, P 实发i is the actual active power generated by each inverter, Q i is the reactive power command of each inverter, Q 实发i It is the actual reactive power generated by each inverter.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention provides an autonomous system for voltage over-limit in substations based on active-reactive integrated control. The strategy can be customized and developed based on a power distribution intelligent gateway, a protocol converter and an inverter. The strategy is easy to understand, simple and practical, and has low implementation difficulty. It solves the problem of voltage over-limit in substations in a more practical way. The strategy is allocated according to the output of the inverter, which can ensure that the active power of all photovoltaic outputs is injected into the power grid to the maximum extent. It has good economic benefits and reduces customer complaints caused by rigid shutdowns or centralized power reductions of single users. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 A structural diagram of a substation voltage over-limit autonomous system based on active-reactive integrated control provided by the present invention.

[0055] Figure 2 This is a schematic diagram of the overall control process for autonomous regulation of over-limit voltage in the substation.

[0056] Figure 3 This is a schematic diagram of the local control process for autonomous regulation of voltage over-limit in the substation.

[0057] Figure 4 This is a schematic diagram of the strategy for the local control method for autonomous regulation of voltage over-limit in the substation. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0059] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0060] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0061] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0062] In order to fully understand the present invention, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail as follows, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0063] See also Figure 1On the one hand, the present invention also provides an autonomous system for voltage over-limit in a substation based on active-reactive integrated control, including a group control and group dispatching master station, a distribution intelligent gateway, a protocol converter and an inverter. The group control and group dispatching master station communicate with the distribution intelligent gateway through a 4G network. The distribution intelligent gateway receives instructions from the group control and group dispatching master station, and sends telesignaling and telemetry information to the group control and group dispatching master station. The distribution intelligent gateway communicates with the protocol converter through a broadband power line carrier HPLC. The distribution intelligent gateway receives the operating information of the inverter, and can decompose the received active and reactive instructions of the distribution intelligent gateway to each inverter. The protocol converter communicates with the inverter through the RS-485 protocol. The protocol converter is used to forward the adjustment instructions issued by the distribution intelligent gateway to each inverter, and collect inverter data and execution results and send them to the distribution intelligent gateway.

[0064] For example, see Figure 2 The group control and group dispatching master station sends all photovoltaic control indicators, giving priority to non-controllable users, predicting the power generation curves of remaining users based on historical power generation curves and climate data, and sending active and reactive commands to each substation. The distribution intelligent gateway receives the active and reactive commands sent by the master station, and at the same time, it coordinates and judges AGC and AVC according to the current voltage over-limit situation in the substation. When in the same direction, the execution strategy is superimposed, and when in the reverse direction, the local strategy is executed to lock the master station command; according to the control principle of the output size of each new energy connected to the substation, the reactive power adjustment command is issued first, and when the reactive power has reached the upper and lower limits, the active power adjustment command is issued, and then the control strategy issued by the distribution intelligent gateway is received and executed through the protocol converter, and the execution results of the control strategy are tracked and reported. The distribution intelligent gateway calculates and reports the execution results of the substation control strategy, and the group control and group dispatching master station calculates the execution results of all control strategies according to the execution results of the reported substation control strategy.

[0065] Customized development of strategies can be completed based on the power distribution intelligent gateway, protocol converter and inverter. The strategies are easy to understand, simple and practical, easy to implement, and can more practically solve the problem of voltage exceeding the limit in the substation.

[0066] For details, see Figure 3 The power distribution intelligent gateway includes a metering module, a strategy module, a 104 protocol module, a 4G module, a 645 protocol module, and an HPLC module. The metering module is used to collect the grid connection points of the voltage transformer PT and the current transformer CT, and output the results to the strategy module. The strategy module is used to generate adjustment instructions. The 645 protocol module receives the adjustment instructions of the strategy module and sends them to the inverter through the HPLC module. At the same time, the inverter sends the inverter information to the 645 protocol module through the HPLC module, and the group control and group adjustment master station sends it to the strategy module through the 4G module through the 104 protocol module.

[0067] Specifically, the strategy module is also used to send the station area information to the protocol module 104.

[0068] For example, the strategy allocation considers allocation strategies under different situations to maximize the economic benefits for users; due to the use of flexible regulation, regulation instructions can be issued to all inverters simultaneously, and the number of instructions issued needs to consider the current output problem.

[0069] On the other hand, see Figure 4 The present invention also provides a voltage over-limit autonomous method for a substation based on active-reactive integrated control, the method is applied to the system, and the method comprises the following steps:

[0070] S1: Calculate the operation data of the substation area, and receive the active power P of the substation area calculated by the metering module through the strategy module 台 , reactive power Q 台 , voltage U 台 And the sensitivity coefficient K of active power to grid connection point voltage 有 ;

[0071] S2: Set the voltage over-limit value, and set the starting voltage over-limit adjustment criteria according to the voltage over-limit value, as follows:

[0072] When U 台 >U setH When U 台 <U setL When it exceeds the lower limit, the U setH Indicates that the voltage is below the limit value, the U setL Indicates that the voltage is below the limit value;

[0073] S3: When U 台 >U setH When the charging time is up, the energy storage regulation instruction that needs to be charged is issued;

[0074] S4: After the energy storage regulation instruction is issued, it is delayed to re-determine whether the voltage exceeds the limit. If it does not exceed the limit, the local regulation ends. If the voltage still exceeds the limit, the output of reactive power and active power is reduced, and a power regulation instruction for each inverter is generated;

[0075] S5: When U 台 <U setL , issue energy storage regulation instructions that need to be discharged;

[0076] S6: After the energy storage regulation instruction is issued, it is delayed to re-determine whether the voltage exceeds the limit. If it does not exceed the limit, the local regulation ends. If the voltage still exceeds the limit, the output of reactive power and active power is increased, and a power regulation instruction is generated for each inverter.

[0077] Specifically, the specific process of step S4 includes:

[0078] S41: Reduce reactive power output: When issuing reactive power instructions, it is necessary to allocate reactive power instructions to each inverter. The greater the inverter output, the greater the reactive power reduction responsibility it bears;

[0079] The calculation formula for the reactive power reduction of each inverter is:

[0080]

[0081] Among them, Q 当前i is the current actual reactive power of the i-th inverter, ∑Q 当前i is the sum of the current reactive power of all inverters in the area, ΔQ 减 is the total amount of reactive power that needs to be reduced, ΔQ 减i is the reactive power reduced by the i-th inverter;

[0082] Then the reactive power command of each inverter is Q i =Q 当前i +ΔQ 减i , Q i is the reactive power instruction of the i-th inverter;

[0083] S42: Reduce the output of active power: When issuing the active power adjustment command, it is necessary to allocate the active power command of each inverter, and set the greater the output of each inverter, the greater the responsibility of reducing the active power;

[0084] The calculation formula for reducing the active power of each inverter is:

[0085]

[0086] Among them, P 当前i is the current active power of the i-th inverter, ∑P 当前i is the sum of the actual active power of all inverters in the area, ΔP 减 is the total amount of active power that needs to be reduced, ΔP 减i The active power reduced by the i-th inverter;

[0087] Among them, △P 减 =(U 台 -U setH ) / K 有；

[0088] Then the active power command of each inverter is P i =P 当前i -ΔP 减i , P i is the active power command of the i-th inverter.

[0089] Specifically, the specific process of step S6 includes:

[0090] S61: increasing the output of active power: when issuing active power instructions, it is necessary to allocate active power instructions for each inverter, and the greater the output of each inverter, the smaller the responsibility for increasing active power;

[0091] The calculation formula for increasing the active power of each inverter is:

[0092]

[0093] Among them, P 当前i is the current active power of each inverter, ∑P 当前i is the sum of the active power generated by all inverters in the area, ΔP 增 is the total amount of active power that needs to be increased, ΔP 增i The active power adjusted up by the i-th inverter;

[0094] Among them, △P 增 =(U setL -U 台 ) / K 有 ;

[0095] Then the active power instruction of each inverter is P i =P 当前i +ΔP 增i , P i is the active power instruction of the i-th inverter;

[0096] S62: Increase the output of active power: when issuing reactive power instructions, it is necessary to allocate reactive power instructions to each inverter, and the greater the inverter output, the smaller the responsibility for increasing reactive power;

[0097] The calculation formula for the reactive power increase of each inverter is:

[0098]

[0099] Among them, Q 当前i is the current reactive power of each inverter, ∑Q 当前i is the sum of the reactive power generated by all inverters in the area, ΔQ 增 is the total amount of reactive power that needs to be added, ΔQ 增i is the reactive power adjusted up by the i-th inverter;

[0100] Then the reactive power command of each inverter is Q i =Q 当前i +ΔQ 增i , Q iis the reactive power instruction of the i-th inverter.

[0101] Specifically, the method further includes, when there is an AGC dispatching instruction or an AVC dispatching instruction, considering the coordination and cooperation between the energy storage adjustment instruction and the AGC dispatching instruction or the AGC dispatching instruction:

[0102] Exemplarily, the method also considers the AGC scheduling instruction problem. Solutions are proposed for strategies with and without AGC control instructions, wherein the coordination method with AGC control instructions is described, and the allocation strategy of AGC scheduling instructions is also described.

[0103] Exemplarily, the method also considers the AVC scheduling instruction problem. Solutions are proposed for strategies with and without AVC control instructions, wherein the coordination method with AVC control instructions is described, and the allocation strategy of AVC scheduling instructions is also described.

[0104] When the voltage exceeds the limit in the substation, the local strategy takes priority, the power command of the inverter is completely generated locally, and the AGC dispatch command and AGC dispatch command are blocked;

[0105] When the voltage in the substation exceeds the limit, it needs to be redistributed in accordance with the AGC dispatching instructions and the AGC dispatching instructions. The distribution principle is to distribute the regulated power according to the capacity ratio:

[0106] The active power that needs to be adjusted by the AGC dispatch instruction is: △P agc =P agc -∑P 实发i ;

[0107] The reactive power that needs to be adjusted by the AGC dispatch instruction is: △Q avc =Q aVc -∑Q 实发i ;

[0108] Among them, △P agc is the active power that needs to be adjusted by the AGC dispatch instruction, P agc is the AGC scheduling instruction, ∑P 实发i is the actual active power generated by all inverters, △Q avc is the reactive power that needs to be adjusted by the AGC dispatch instruction, Q aVc is the AGC scheduling instruction, ∑Q 实发i is the actual reactive power generated by all inverters;

[0109] When there is an AGC scheduling instruction or an AVC scheduling instruction, the regulated power of each inverter is:

[0110]

[0111] Among them, △P i is the regulated active power of the i-th inverter when there is an AGC dispatch instruction or an AVC dispatch instruction, P 额定i is the rated active power of each inverter, △Q i is the regulated reactive power of the i-th inverter when there is an AGC dispatch instruction or an AVC dispatch instruction, Q 额定i is the rated reactive power of each inverter;

[0112] Then the power command of each inverter is: P i =P 实发i +△P i , Q i =Q 实发i +△Q i ;

[0113] Among them, P i is the active power command of each inverter, P 实发i is the actual active power generated by each inverter, Q i is the reactive power command of each inverter, Q 实发i It is the actual reactive power generated by each inverter.

[0114] Exemplarily, the present invention distributes power according to the output size of the inverter. When the voltage exceeds the upper limit, energy storage charging is prioritized, then reactive power is reduced, and finally active power is reduced. The reduced reactive power and active power are both distributed according to the output size. The larger the output of the inverter, the greater the reduction.

[0115] When the voltage is at the lower limit, energy storage is discharged first, then active power is increased, and finally reactive power is increased. The increased reactive and active power are distributed according to the output size. The inverter with larger output has smaller increase, which can ensure that the active power of all photovoltaic outputs is injected into the grid to the maximum extent. It has good economic benefits and reduces customer complaints caused by rigid shutdown or centralized power reduction of single users.

[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A voltage over-limit autonomous system based on active-reactive integrated control, characterized in that: It includes a group control and group dispatching master station, a power distribution intelligent gateway, a protocol converter and an inverter. The group control and group dispatching master station communicates with the power distribution intelligent gateway through a 4G network. The power distribution intelligent gateway receives instructions from the group control and group dispatching master station, and sends telesignaling and telemetry information to the group control and group dispatching master station. The power distribution intelligent gateway communicates with the protocol converter through a broadband power line carrier HPLC. The power distribution intelligent gateway receives the operating information of the inverter, and can decompose the received active and reactive instructions of the power distribution intelligent gateway to each inverter. The protocol converter communicates with the inverter through the RS-485 protocol. The protocol converter is used to forward the adjustment instructions issued by the power distribution intelligent gateway to each inverter, and collect inverter data and execution results and send them to the power distribution intelligent gateway.

2. The voltage over-limit autonomous system based on active-reactive integrated control in the substation area according to claim 1 is characterized in that: The power distribution intelligent gateway includes a metering module, a strategy module, a 104 protocol module, a 4G module, a 645 protocol module, and an HPLC module. The metering module is used to collect the grid connection points of the voltage transformer PT and the current transformer CT, and output the results to the strategy module. The strategy module is used to generate adjustment instructions. The 645 protocol module receives the adjustment instructions of the strategy module and sends them to the inverter through the HPLC module. At the same time, the inverter sends the inverter information to the 645 protocol module through the HPLC module, and the group control and group adjustment master station sends it to the strategy module through the 4G module through the 104 protocol module.

3. The voltage over-limit autonomous system based on active-reactive integrated control in the substation area according to claim 2 is characterized in that: The strategy module is also used to send the station area information to the protocol module 104.

4. A voltage over-limit autonomous method for a substation based on active-reactive integrated control, the method being applied to a system as claimed in any one of claims 1 to 3, characterized in that: The method comprises the following steps: S1: Calculate the operation data of the substation area, and receive the active power P of the substation area calculated by the metering module through the strategy module 台 , reactive power Q 台 , voltage U 台 And the sensitivity coefficient K of active power to grid connection point voltage 有 ; S2: Set the voltage over-limit value, and set the starting voltage over-limit adjustment criteria according to the voltage over-limit value, as follows: When U 台 >U setH When U 台 <U setL When the lower limit is exceeded, the U setH Indicates that the voltage is below the limit value, the U setL Indicates that the voltage is below the limit value; S3: When U 台 >U setH When the charging time is up, the energy storage regulation instruction that needs to be charged is issued; S4: After the energy storage regulation instruction is issued, it is delayed to re-determine whether the voltage exceeds the limit. If it does not exceed the limit, the local regulation ends. If the voltage still exceeds the limit, the output of reactive power and active power is reduced, and a power regulation instruction for each inverter is generated; S5: When U 台 <U setL , issue energy storage regulation instructions that need to be discharged; S6: After the energy storage regulation instruction is issued, it is delayed to re-determine whether the voltage exceeds the limit. If it does not exceed the limit, the local regulation ends. If the voltage still exceeds the limit, the output of reactive power and active power is increased, and a power regulation instruction is generated for each inverter.

5. The method for controlling voltage over-limit in a substation area based on active-reactive integrated control according to claim 4, characterized in that: The specific process of step S4 includes: S41: Reduce reactive power output: When issuing reactive power instructions, it is necessary to allocate reactive power instructions to each inverter. The greater the inverter output, the greater the reactive power reduction responsibility it bears; The calculation formula for the reactive power reduction of each inverter is: Among them, Q 当前i is the current actual reactive power of the i-th inverter, ∑Q 当前i is the sum of the current reactive power of all inverters in the area, ΔQ 减 is the total amount of reactive power that needs to be reduced, ΔQ 减i is the reactive power reduced by the i-th inverter; Then the reactive power command of each inverter is Q i =Q 当前i +ΔQ 减i , Q i is the reactive power instruction of the i-th inverter; S42: Reduce the output of active power: When issuing the active power adjustment command, it is necessary to allocate the active power command of each inverter, and set the greater the output of each inverter, the greater the responsibility of reducing the active power; The calculation formula for the active power reduction of each inverter is: Among them, P 当前i is the current active power of the i-th inverter, ∑P 当前i is the sum of the actual active power of all inverters in the area, ΔP 减 is the total amount of active power that needs to be reduced, ΔP 减i The active power reduced by the i-th inverter; Then the active power command of each inverter is P i =P 当前i -ΔP 减i , P i is the active power command of the i-th inverter.

6. The method for controlling voltage over-limit in a substation area based on active-reactive integrated control according to claim 5, characterized in that: The specific process of step S6 includes: S61: increasing the output of active power: when issuing active power instructions, it is necessary to allocate active power instructions for each inverter, and the greater the output of each inverter, the smaller the responsibility for increasing active power; The calculation formula for increasing the active power of each inverter is: Among them, P 当前i is the current active power of each inverter, ∑P 当前i is the sum of the active power generated by all inverters in the area, ΔP 增 is the total amount of active power that needs to be increased, ΔP 增i The active power adjusted up by the i-th inverter; Then the active power instruction of each inverter is P i =P 当前i +ΔP 增i , P i is the active power instruction of the i-th inverter; S62: Increase the output of active power: when issuing reactive power instructions, it is necessary to allocate reactive power instructions to each inverter, and the greater the inverter output, the smaller the responsibility for increasing reactive power; The calculation formula for the reactive power increase of each inverter is: Among them, Q 当前i is the current reactive power of each inverter, ∑Q 当前i is the sum of the reactive power generated by all inverters in the area, ΔQ 增 is the total amount of reactive power that needs to be added, ΔQ 增i is the reactive power adjusted up by the i-th inverter; Then the reactive power command of each inverter is Q i =Q 当前i +ΔQ 增i , Q i is the reactive power instruction of the i-th inverter.

7. The method for controlling voltage over-limit in a substation area based on active-reactive integrated control according to claim 6, characterized in that: The method further includes, when there is an AGC dispatching instruction or an AVC dispatching instruction, considering the coordination and cooperation between the energy storage adjustment instruction and the AGC dispatching instruction or the AGC dispatching instruction: When the voltage exceeds the limit in the substation, the local strategy takes priority, the power command of the inverter is completely generated locally, and the AGC dispatch command and AGC dispatch command are blocked; When the voltage in the substation exceeds the limit, it needs to be redistributed in accordance with the AGC dispatching instructions and the AGC dispatching instructions. The distribution principle is to distribute the regulated power according to the capacity ratio: The active power that needs to be adjusted by the AGC dispatch instruction is: △P agc =P agc -∑P 实发i ; The reactive power that needs to be adjusted by the AGC dispatch instruction is: △Q avc =Q aVc -∑Q 实发i ; Among them, △P agc is the active power that needs to be adjusted by the AGC dispatch instruction, P agc is the AGC scheduling instruction, ∑P 实发i is the actual active power generated by all inverters, △Q avc is the reactive power that needs to be adjusted by the AGC dispatch instruction, Q aVc is the AGC scheduling instruction, ∑Q 实发i is the actual reactive power generated by all inverters; When there is an AGC scheduling instruction or an AVC scheduling instruction, the regulated power of each inverter is: Among them, △P i is the regulated active power of the i-th inverter when there is an AGC dispatch instruction or an AVC dispatch instruction, P 额定i is the rated active power of each inverter, △Q i is the regulated reactive power of the i-th inverter when there is an AGC dispatch instruction or an AVC dispatch instruction, Q 额定i is the rated reactive power of each inverter; Then the power command of each inverter is: P i =P 实发i +△P i , Q i =Q 实发i +△Q i ; Among them, P i is the active power command of each inverter, P 实发i is the actual active power generated by each inverter, Q i is the reactive power command of each inverter, Q 实发i It is the actual reactive power generated by each inverter.

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