A reactive voltage coordination control method between new energy stations

Abstract

This invention proposes a reactive power and voltage coordination control method among renewable energy power plants, comprising: dividing renewable energy power plants within a renewable energy area controlled by an AVC master station into voltage source type power plants and reactive power source type power plants; calculating the adjustment amount of reactive power output of the equivalent renewable energy generating units according to the current control mode of the AVC master station, thereby obtaining the high-voltage side voltage setpoint and the grid connection point reactive power setpoint of the renewable energy power plants; the AVC master station issues the high-voltage side bus voltage setpoint to the voltage source type power plants and controls them according to the constant voltage control mode; and issues the grid connection point reactive power setpoint and voltage static safety domain to the reactive power source type power plants and controls them according to the constant reactive power control mode. This invention fully considers the differences in reactive power and voltage regulation among renewable energy power plants and issues different types of instructions, thereby achieving better regulation effects, suppressing reactive power circulation between renewable energy power plants, realizing refined coordination among renewable energy power plants within the region, and improving the safe and stable operation level of the power grid.

Description

Technical Field

[0001] This invention belongs to the field of automatic voltage control technology for power grids, and specifically relates to a method for coordinated control of reactive power and voltage between new energy power plants. Background Technology

[0002] In recent years, my country's annual grid-connected capacity of new energy has remained at a high level. The large-scale grid connection of new energy has provided strong support for the energy transition to clean and low-carbon energy. However, due to the intermittency and volatility of new energy, some problems have also arisen, among which reactive power circulation between new energy power plants is a relatively significant issue.

[0003] Modern power systems typically install Automatic Voltage Control (AVC) systems in the power grid control center. These systems monitor the grid's voltage status in real time and generate commands based on the grid's reactive power and voltage operation to control equipment in substations and power plants. For substations, some AVC master stations provide direct control, issuing remote control commands to regulate reactive power and voltage through capacitive reactors. Others provide indirect control, issuing reactive power regulation commands or reactive power and voltage constraints to the central control station or lower-level dispatch center, which then generates specific control commands to regulate reactive power and voltage. Power plants generally have AVC slave stations. The AVC master station typically issues voltage control commands to these slave stations, which then regulate various reactive power equipment within the plant. Due to the numerous control objects and methods of the AVC master station, its control cycle cannot be set too short, typically around 5 minutes.

[0004] To address the reactive power circulation problem among renewable energy power plants, the AVC master station incorporates a plant-to-plant coordination strategy during policy calculations to ensure overall reactive power output balance across all renewable energy power plants. However, because the final command issued by the AVC master station to the AVC substations at the renewable energy power plants is a voltage control command, and the internal setpoint parameters of each AVC substation are not entirely identical—reactive power regulation step size, reactive power regulation rate, voltage regulation step size, and voltage regulation rate are all different—and the response performance of the reactive power equipment at each renewable energy power plant also varies, the reactive power circulation between the renewable energy power plants persists even though the AVC substations have adjusted the voltage to the appropriate level. Some solutions convert the final instructions issued by the AVC master station to the renewable energy power plant into reactive power instructions, and the AVC substation adjusts according to the reactive power instructions. This can effectively solve the reactive power circulation problem between power plants. However, since the AVC master station only issues a round of instructions every 5 minutes, and the active power of the renewable energy power plant sometimes fluctuates very drastically, the voltage of the renewable energy power plant fluctuates drastically. If the AVC substation only follows the reactive power instructions, it may cause voltage instability within the renewable energy power plant, which could lead to a very serious accident. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a reactive power and voltage coordination control method among renewable energy power plants. Based on the classic Coordinated Two-Stage Voltage Control (CSVC), this invention fully considers the differences in reactive power and voltage regulation among renewable energy power plants, classifying them into "voltage source" and "reactive power source" types and issuing different types of instructions. This achieves better regulation results, suppresses reactive power circulation among renewable energy power plants, realizes refined coordination among renewable energy power plants within a region, and improves the safe and stable operation of the power grid.

[0006] This invention proposes a reactive power and voltage coordination control method among new energy power plants, comprising:

[0007] The new energy power stations within the new energy area controlled by the AVC master station are divided into voltage source type power stations and reactive power source type power stations.

[0008] Based on the current control mode of the AVC master station, calculate the adjustment amount of reactive power output of the new energy equivalent unit;

[0009] Based on the adjustment of the reactive power output of the equivalent new energy unit, calculate the high-voltage side voltage setting value and the reactive power setting value at the grid connection point of the new energy power station;

[0010] The AVC master station issues the high-voltage side bus voltage setpoint to the voltage source type substation and controls it according to the constant voltage control mode; it issues the grid connection point reactive power setpoint and voltage static safety domain to the reactive power source type substation and controls it according to the constant reactive power control mode.

[0011] In one specific embodiment of the present invention, it further includes:

[0012] The current control modes of the AVC master station include proactive prevention control and lag correction control;

[0013] If the central bus of the new energy area is not adjusted in place, then proactive preventive control should be implemented.

[0014] If the central bus of the new energy region is adjusted to the required level, then lag correction control will be implemented.

[0015] In one specific embodiment of the present invention, it further includes:

[0016] Under the aforementioned proactive prevention and control, a quadratic programming model for proactive prevention and control is established and solved;

[0017] The quadratic programming model expression for the proactive prevention and control is as follows:

[0018]

[0019] The following constraints must be satisfied:

[0020]

[0021]

[0022]

[0023]

[0024]

[0025] in, This represents the k-th factory coordination group; This indicates the reactive power balance index of the equivalent renewable energy generating unit; This is the dead zone for reactive power balance index;

[0026] Determined by the following formula:

[0027]

[0028] in, This indicates the adjustment amount of reactive power output of the equivalent renewable energy generating unit; , and These represent the current reactive power, lower reactive power limit, and upper reactive power limit of the equivalent renewable energy generating unit, respectively. Represents the reactive power balance index of the i-th renewable energy equivalent unit; and These are the weighting coefficients. The weighting coefficient represents the target voltage regulation of the central bus. The weighting coefficient represents the reactive power balance target of equivalent renewable energy units. This is the gain coefficient; , , and These represent the current voltage of the central bus, the voltage deviation of the central bus, the lower limit of the central bus voltage, and the upper limit of the central bus voltage, respectively. , , , and These represent the current voltage, lower voltage limit, upper voltage limit, maximum single-step adjustment, and voltage adjustment amount of the high-voltage side busbar of the main transformer at the new energy power station, respectively. and These are the sensitivity matrices of the new energy equivalent generating units to the central bus and the sensitivity matrix of the new energy equivalent generating units to the high-voltage side bus of the main transformer, respectively, satisfying:

[0029]

[0030]

[0031] Solving the quadratic programming model yields the following results: The optimization results.

[0032] In one specific embodiment of the present invention, it further includes:

[0033] Under the lag correction control, a quadratic programming model for the lag correction control is established and solved.

[0034] The quadratic programming model expression for the lag correction control is as follows:

[0035]

[0036] The following constraints must be satisfied:

[0037]

[0038]

[0039]

[0040]

[0041] - ≤ ≤

[0042] in, Representatives from the factory coordination team gathered. This represents the i-th factory coordination group; This indicates the reactive power balance index of the equivalent renewable energy generating unit; This is the dead zone for central bus voltage control. and These are the weighting coefficients. The weighting coefficient represents the reactive power coordination target among new energy power plants. The weighting coefficient represents the reactive power balance target of equivalent renewable energy generating units;

[0043] Solving the quadratic programming model yields the following results: The optimization results.

[0044] In a specific embodiment of the present invention, the calculation of the high-voltage side voltage setting value and the reactive power setting value at the grid connection point of the new energy power station includes:

[0045] Adjustment based on reactive power output of equivalent new energy generating units Sensitivity matrix of high-voltage side bus Calculate the adjustment amount of the high-voltage side bus voltage setpoint of the new energy power station. ;

[0046] For new energy power stations i, based on The adjustment amount of the high-voltage side voltage setpoint of the new energy power station i is obtained as follows: ;based on The reactive power adjustment of the renewable energy units belonging to renewable energy power station i is accumulated to obtain the reactive power setpoint adjustment of renewable energy power station i. ;

[0047] Record the real-time value of the current high-voltage side bus voltage of the new energy power station i collected by the AVC master station. The collected reactive power value at the grid connection point The upper limit of the high-voltage bus voltage control for new energy power station i is set as follows: The lower limit of the high-voltage side bus voltage control is The upper limit of reactive power control at the grid connection point is The lower limit of reactive power control at the grid connection point is ;

[0048] Adjustment amount based on the high-voltage side bus voltage setting value of new energy power station i The high-voltage side bus voltage setting value of new energy power station i is obtained. And perform voltage control upper and lower limit verification:

[0049] like Then let ;like Then let Otherwise, keep constant;

[0050] Reactive power setpoint adjustment based on new energy power station i The reactive power setpoint of the grid connection point of the new energy power station i is obtained. And perform reactive power control upper and lower limit verification:

[0051] like Then let ;like Then let Otherwise, keep constant.

[0052] In one specific embodiment of the present invention, it further includes:

[0053] When a voltage source type power station is controlled in constant voltage control mode, the voltage setpoint received by the power station's AVC substation from the AVC master station is... Among them, for new energy power stations i, That is Data collection station grid connection point , , ,in Indicates the bus voltage value at the grid connection point. Indicates the active power value of the outgoing line from the grid connection point. Indicates the reactive power value of the outgoing line from the grid connection point; Record The voltage adjustment step size for each round, The step size for reactive power regulation in each round is given; the voltage regulation amount is calculated as follows: Then determine:

[0054] like Then let The reactive power regulation is ,in For grid connection point voltage reactive power sensitivity; otherwise, maintain constant;

[0055] Then further determine: if Then let Otherwise, keep Unchanged; then The reactive power regulation is used to adjust the reactive power equipment in the station to meet the voltage regulation requirements of the main station.

[0056] In one specific embodiment of the present invention, it further includes:

[0057] When a reactive power source type power station is controlled according to the constant reactive power control mode, the reactive power setpoint received by the power station's AVC substation from the AVC master station is... Among them, for new energy power stations i, That is Upper limit of voltage static safety domain and lower limit of voltage static safety domain The voltage control dead zone of the AVC substation is The reactive power control dead zone is ;

[0058] If the voltage at the grid connection point of the new energy power station ≥ - In this control cycle, the adjustment requirement of the main station's reactive power setting target value is temporarily abandoned, and an magnetization interlocking signal is sent to the AVC main station. - To control the voltage control target;

[0059] If the voltage at the grid connection point of the new energy power station ≤ + In this control cycle, the reactive power regulation target is temporarily abandoned, and a demagnetization lockout signal is sent to the AVC master station. + To control the voltage control target;

[0060] like + < < - Then the AVC substation of that station will be... To achieve the control objective, the reactive power adjustment is controlled. ,right Perform verification; among which, let , , , Then determine:

[0061] like > Then let = ;like < Then let = Otherwise, keep constant;

[0062] Then further determine: if Then let Otherwise, keep Unchanged; then To adjust the reactive power of the equipment in the power station to meet the reactive power regulation requirements of the main station.

[0063] In one specific embodiment of the present invention, it further includes:

[0064] When the AVC substation of the new energy power station does not receive instructions from the AVC master station within a set time period, it switches to local control;

[0065] When under local control, the AVC substation switches to constant voltage control mode and controls according to the set voltage curve;

[0066] Wherein, the default setting value of the voltage obtained from the voltage curve at time T is... The voltage adjustment step size of the AVC substation in the new energy power station during the switching process of different control modes. The step size of reactive power adjustment in each round , This is the reduction factor during the switching process; the bus voltage at the grid connection point is... Calculate the voltage regulation amount Then determine:

[0067] like Then let Otherwise, keep constant;

[0068] Calculate the reactive power regulation as follows: Then determine:

[0069] like Then let Otherwise, keep Unchanged; then To regulate the reactive power of reactive power equipment within the power station;

[0070] when When restoring the voltage regulation step size of the AVC substation, it is... The reactive power adjustment step size is ;when Long time greater than When switching from the new energy AVC substation to local control, the counting begins, and after N consecutive rounds of voltage regulation, the voltage regulation step size of the AVC substation is restored. The reactive power adjustment step size is .

[0071] In one specific embodiment of the present invention, it further includes:

[0072] When the AVC substation of the renewable energy power station receives another control command from the AVC master station, it switches to remote control, and the power station operates according to the control mode issued by the AVC master station. During the switching process, the voltage adjustment step size of the AVC substation in each round... The step size of reactive power adjustment in each round ;

[0073] When controlling a voltage source type power station using constant voltage control mode, if Then the voltage regulation step size of the restored AVC substation is... The reactive power adjustment step size is Otherwise, keep and constant;

[0074] When a reactive power source type power station is controlled according to the constant reactive power control mode, if Then the reactive power adjustment step size of the restored AVC substation is... Otherwise, keep and constant;

[0075] The counting begins when switching from AVC substation to remote control, and the voltage regulation step size after M consecutive rounds of voltage regulation is [value missing]. The reactive power adjustment step size is .

[0076] Features and beneficial effects of the present invention:

[0077] 1) This invention fully considers the differences in reactive power and voltage regulation performance of new energy power plants. When controlling new energy power plants, the AVC master station classifies them into "voltage source" type plants and "reactive power source" type plants. For "voltage source" type plants, voltage control commands are issued to ensure voltage stability throughout the area. For "reactive power source" type plants, reactive power control commands and voltage static safety domain limit constraints are issued to resolve reactive power circulation between plants. The AVC substation needs to simultaneously possess both constant voltage control mode and constant reactive power control mode. For "voltage source" type plants, control is always performed in constant voltage mode. For "reactive power source" type plants, when they normally receive commands from the AVC master station, control is performed in constant reactive power mode. When they do not receive commands from the AVC master station, they switch to local control and simultaneously switch to constant voltage control mode, controlling according to the default voltage setting curve.

[0078] 2) This invention can better solve the problem of reactive power circulation between new energy power plants, thereby rationally optimizing the reactive power reserve in new energy areas, improving the safe and stable operation of the power grid, and indirectly promoting the consumption and utilization of new energy. Attached Figure Description

[0079] Figure 1 This is an overall flowchart of a reactive power and voltage coordination control method between new energy power plants according to an embodiment of the present invention. Detailed Implementation

[0080] This invention proposes a method for coordinated control of reactive power and voltage between new energy power plants, which is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0081] This invention proposes a reactive power and voltage coordination control method among new energy power plants, comprising:

[0082] The new energy power stations within the new energy area controlled by the AVC master station are divided into voltage source type power stations and reactive power source type power stations.

[0083] Based on the current control mode of the AVC master station, calculate the adjustment amount of reactive power output of the new energy equivalent unit;

[0084] Based on the adjustment of the reactive power output of the equivalent new energy unit, calculate the high-voltage side voltage setting value and the reactive power setting value at the grid connection point of the new energy power station;

[0085] The AVC master station issues the high-voltage side bus voltage setpoint to the voltage source type substation and controls it according to the constant voltage control mode; it issues the grid connection point reactive power setpoint and voltage static safety domain to the reactive power source type substation and controls it according to the constant reactive power control mode.

[0086] In a specific embodiment of the present invention, the overall process of the reactive power and voltage coordination control method between new energy power plants is as follows: Figure 1 As shown, it includes the following steps:

[0087] 1) The AVC master station targets the new energy area and controls the new energy power stations belonging to that area; the new energy power stations in the area are divided into "voltage source" type power stations and "reactive power source" type power stations.

[0088] For "voltage source" type power stations, the following factors should be considered when selecting them: the installed capacity of the new energy power station, the outgoing line capacity of the new energy power station (the number of lines connected to the new energy power station), and whether the new energy power station has installed distributed synchronous condenser equipment.

[0089] In this embodiment, new energy power stations with large installed capacity, high outgoing line density, and distributed synchronous condensers are preferentially selected as "voltage source" type power stations. The proportion of "voltage source" type power stations in this area should not be less than 30%, and the other power stations are set as "reactive power source" type power stations.

[0090] 2) The AVC master station considers the power generation trend changes in the new energy area over a period of time in the future, predicts the voltage trend changes in the new energy area over a period of time based on the trend changes in active power generation, and also considers the voltage changes after the N-1 fault in the new energy area, and calculates the voltage static security domain of the new energy area.

[0091] In this embodiment, for new energy power station i, the static safety domain of the high-voltage side bus voltage of the power station can be calculated as ( , ),in This is the lower limit for the safe operation of voltage at the new energy power station i. This represents the upper limit of voltage safety operation for renewable energy power station i. The calculation period for the voltage static safety domain is generally no more than 15 minutes.

[0092] 3) Determine the current control mode of the AVC master station.

[0093] When controlling power plants in renewable energy areas, the AVC master station typically employs Coordinated Secondary Voltage Control (CSVC). For plant-to-plant coordinated control, there are generally two methods: proactive prevention control and lag correction control.

[0094] If the central bus of the current new energy area has not been adjusted in place, proceed to step 4) to carry out advanced preventive control. It is necessary to follow the three-level optimization set value and at the same time avoid the imbalance of reactive power output of each new energy station as much as possible.

[0095] If the central bus of the current new energy area is adjusted in place, proceed to step 5) to carry out lag correction control and restore the uncoordinated plant coordination groups to a "balanced" state.

[0096] 4) Establish and solve a quadratic programming model for advanced prevention and control to obtain the adjustment amount of reactive power output of the equivalent new energy unit.

[0097] In this embodiment, the quadratic programming model expression for proactive prevention and control is as follows:

[0098]

[0099] The following constraints must be satisfied:

[0100] (C0)

[0101] (C1)

[0102] (C2)

[0103] (C3)

[0104] (C4)

[0105] The quadratic programming mathematical model is the optimization objective of the traditional CSVC (Coordinated Second-Level Voltage Control Model), C0~C3 are the optimization constraints of the traditional CSVC, and C4 is the plant-to-plant coordination constraint. This represents the k-th factory coordination group; This indicates the reactive power balance index of the equivalent renewable energy generating unit; This is the dead zone for reactive power balance index.

[0106] Determined by the following formula:

[0107]

[0108] in, As a control variable, it represents the adjustment amount of reactive power output of the equivalent new energy generating unit. , and These represent the current reactive power, lower reactive power limit, and upper reactive power limit of the controlled new energy equivalent generating unit, respectively. Let represent the reactive power balance index of the i-th equivalent new energy unit. and These are the weighting coefficients. The weighting coefficient represents the target voltage regulation of the central bus. The weighting coefficient represents the reactive power balance target of equivalent renewable energy units. Gain coefficient ( The value range is generally 10-100. The value range is 0.01-0.2. The typical value range is 0.8-1.2). , , and These represent the current voltage of the central bus, the voltage deviation of the central bus, the lower limit of the central bus voltage, and the upper limit of the central bus voltage, respectively. , , , and These represent the current voltage, lower voltage limit, upper voltage limit, maximum single-step adjustment, and voltage adjustment amount of the high-voltage side bus of the main transformer at the new energy power station. and These are the sensitivity matrices of the new energy equivalent generating units to the central bus and the sensitivity matrix of the new energy equivalent generating units to the high-voltage side bus of the main transformer, respectively, satisfying:

[0109]

[0110]

[0111] Solving the quadratic programming model yields the following results: The optimization results are then used to proceed to step 6).

[0112] 5) Establish and solve the quadratic programming model of lag correction control to obtain the adjustment amount of reactive power output of the equivalent new energy unit.

[0113] In this embodiment, the quadratic programming model expression for lag compensation control is as follows:

[0114]

[0115] The following constraints must be satisfied:

[0116] (C0)

[0117] (C1)

[0118] (C2)

[0119] (C3)

[0120] (C4) - ≤ ≤

[0121] Among them, C0~C3 are traditional CSVC optimization constraints; C4 is a plant-to-plant coordination constraint. Representatives from the factory coordination team gathered. This represents the i-th factory coordination group; This indicates the reactive power balance index of the equivalent renewable energy generating unit; This is the dead zone for central bus voltage control. and These are the weighting coefficients. The weighting coefficient represents the reactive power coordination target among new energy power plants. This represents the weighting coefficient for the reactive power balance target of equivalent new energy generating units.

[0122] Solving the quadratic programming model yields the following results: The optimization results are then used to proceed to step 6).

[0123] 6) Based on the adjustment of reactive power output of equivalent new energy units, calculate the high-voltage side bus voltage setting value and grid connection point reactive power setting value of new energy power stations.

[0124] In this embodiment, the adjustment amount is based on the reactive power output of the equivalent renewable energy unit. Sensitivity matrix of high-voltage side bus Calculate the adjustment amount of the high-voltage side bus voltage setpoint of the new energy power station. .

[0125] Among them, for new energy power station i, based on The adjustment amount of the high-voltage side voltage setting value of the new energy power station i can be obtained as follows: ;based on By summing the reactive power adjustments of the renewable energy units belonging to renewable energy power station i, we can obtain the reactive power setpoint adjustment of renewable energy power station i as follows: .

[0126] Record the real-time value of the current high-voltage side bus voltage of the new energy power station i collected by the AVC master station. The collected reactive power value at the grid connection point The upper limit of the high-voltage bus voltage control for new energy power station i is set as follows: The lower limit of the high-voltage side bus voltage control is The upper limit of reactive power control at the grid connection point is The lower limit of reactive power control at the grid connection point is .

[0127] Adjustment amount based on the high-voltage side bus voltage setting value of new energy power station i The high-voltage side bus voltage setting value of new energy power station i is obtained. And perform voltage control upper and lower limit verification:

[0128] like Then let ;like Then let Otherwise, keep constant.

[0129] Reactive power setpoint adjustment based on new energy power station i The reactive power setpoint of the grid connection point of the new energy power station i is obtained. And perform reactive power control upper and lower limit verification:

[0130] like Then let ;like Then let Otherwise, keep constant.

[0131] 7) Based on the results of step 6), the AVC master station issues the corresponding control mode word according to the type of new energy power station.

[0132] In this embodiment, if the new energy power station i is a "voltage source" type power station, the AVC master station sends a voltage setpoint to it. At the same time, control mode words are issued. ,at this time It is 100.

[0133] If the new energy power station i is a "reactive power source" type power station, then the AVC master station will issue a reactive power setpoint to it. Upper limit of voltage static safety domain and lower limit of voltage static safety domain At the same time, control mode words are issued. ,at this time It is 200.

[0134] 8) After receiving the control mode word from the AVC master station, the AVC substation of the new energy power station performs control according to the corresponding control mode; the specific steps are as follows:

[0135] 8-1) When the control mode word received by the AVC substation of the new energy power station is 100, control is performed according to the constant voltage control mode.

[0136] In this embodiment, the voltage setting value received by the AVC substation of the new energy power station from the AVC master station is... (Among them, for new energy power station i, That is ), its data collection stations and grid connection points , , ,in Indicates the bus voltage value at the grid connection point. Indicates the active power value of the outgoing line from the grid connection point. This represents the reactive power value output from the grid connection point. Let... The voltage adjustment step size for each round, Let this be the reactive power adjustment step size for each round. The calculated voltage regulation amount is: Then determine:

[0137] like Then let The reactive power regulation is ,in For grid connection point voltage reactive power sensitivity; otherwise, maintain constant.

[0138] Further considering the reactive power adjustment step size in each round, if Then let Otherwise, keep Unchanged. Then... The reactive power regulation is used to adjust the reactive power equipment in the substation to meet the voltage regulation requirements of the main station.

[0139] 8-2) When the control mode word received by the AVC substation of the new energy power station is 200, control is performed according to the constant reactive power control mode.

[0140] In this embodiment, the reactive power setting value received by the AVC substation of the new energy power station from the AVC master station is... (Among them, for new energy power stations i, That is Voltage static safety domain upper limit) and lower limit of voltage static safety domain The voltage control dead zone of the AVC substation is The reactive power control dead zone is .

[0141] If the voltage at the grid connection point of the new energy power station ≥ - In this control cycle, the adjustment requirement of the main station's reactive power setting target value is temporarily abandoned, and an magnetization interlocking signal is sent to the AVC main station. - Control is performed for the voltage control target.

[0142] If the voltage at the grid connection point of the new energy power station ≤ + In this control cycle, the reactive power regulation target is temporarily abandoned, and a demagnetization lockout signal is sent to the AVC master station. + Control is performed for the voltage control target.

[0143] like + < < - Then the AVC substation uses To achieve the control objective, the reactive power adjustment is controlled. ,right Verification is performed to ensure that the regulated voltage also remains within the static safety range. , , , Then determine:

[0144] like > Then let = ;like < Then let = Otherwise, keep constant.

[0145] Further considering the reactive power adjustment step size in each round, if Then let Otherwise, keep Unchanged. Then... To adjust the reactive power equipment in the power station to meet the reactive power regulation requirements of the main station.

[0146] Furthermore, the method described in this embodiment also includes the following steps:

[0147] 9) When the AVC substation of the new energy power station does not receive instructions from the AVC master station for a long time (usually 15 minutes), it will switch to local control.

[0148] When the AVC substation of the new energy power station is under local control, regardless of whether the AVC substation was in constant voltage or constant reactive power control mode in the previous round of control, the current round of control will switch to constant voltage control mode and control according to the default voltage curve.

[0149] Let the default setting value of the voltage obtained from the voltage curve at time T be... To ensure smooth switching between different control modes at the new energy AVC substation, smaller voltage and reactive power regulation step sizes can be used during the switching process. Let the reduction factor be... , The value can generally be between 0.2 and 0.5. This refers to the voltage adjustment step size of the AVC substation in a new energy power station during the switching process between different control modes. The step size of reactive power adjustment in each round At this time, the bus voltage at the grid connection point is... Calculate the voltage regulation amount Then determine:

[0150] like Then let Otherwise, keep constant.

[0151] Calculate the reactive power regulation as follows: Then determine:

[0152] like Then let Otherwise, keep Unchanged. Then... To regulate the reactive power of reactive power equipment within the power station.

[0153] when When restoring the voltage regulation step size of the AVC substation, it is... The reactive power adjustment step size is ;when Long time greater than When switching from the new energy AVC substation to local control, the counting begins, and after 10 consecutive rounds of voltage regulation, the voltage regulation step size of the AVC substation is restored. The reactive power adjustment step size is .

[0154] When the AVC substation at the renewable energy power station receives another control command from the AVC master station, it switches to remote control and operates according to the control mode word issued by the AVC master station. While the AVC master station considers the reactive power and voltage adjustment step size when issuing commands, the renewable energy AVC substation also needs to take this into account. During the switching process, a smaller voltage and reactive power adjustment step size is also required. The reduction factor at this time... The value can range from 0.5 to 0.7. This refers to the voltage adjustment step size of the AVC substation at the new energy power station during each round of switching. The step size of reactive power adjustment in each round When the control mode word 100 is received, control can be performed according to the logic in step 8-1), except that the voltage adjustment step size for each round is... The step size of reactive power adjustment in each round Similarly, when the control mode word 200 is received, control is performed according to the logic in step 8-2). At this time, the reactive power adjustment step size for each round needs to be adjusted. .

[0155] When the new energy AVC substation controls according to control mode word 100, if Then the voltage regulation step size of the restored AVC substation is... The reactive power adjustment step size is Otherwise, keep and constant.

[0156] When the new energy AVC substation controls according to control mode word 200, if Then the reactive power adjustment step size of the restored AVC substation is... Otherwise, keep and constant.

[0157] In this embodiment, regardless of the control word mode used, counting begins when switching from the new energy AVC substation to remote control. After three consecutive rounds of voltage regulation, the voltage regulation step size of the restored AVC substation is... The reactive power adjustment step size is .

Claims

1. A method for coordinated control of reactive power and voltage between new energy power plants, characterized in that, include: The new energy power stations within the new energy area controlled by the AVC master station are divided into voltage source type power stations and reactive power source type power stations. Based on the current control mode of the AVC master station, calculate the adjustment amount of reactive power output of the new energy equivalent unit; Based on the adjustment of the reactive power output of the equivalent new energy unit, calculate the high-voltage side voltage setting value and the reactive power setting value at the grid connection point of the new energy power station; The AVC master station issues the high-voltage side bus voltage setpoint to the voltage source type substation and controls it according to the constant voltage control mode; it issues the grid connection point reactive power setpoint and voltage static safety domain to the reactive power source type substation and controls it according to the constant reactive power control mode.

2. The method according to claim 1, characterized in that, Also includes: The current control modes of the AVC master station include proactive prevention control and lag correction control; If the central bus of the new energy area is not adjusted in place, then proactive preventive control should be implemented. If the central bus of the new energy region is adjusted to the required level, then lag correction control will be implemented.

3. The method according to claim 2, characterized in that, Also includes: Under the aforementioned proactive prevention and control, a quadratic programming model for proactive prevention and control is established and solved; The quadratic programming model expression for the proactive prevention and control is as follows: The following constraints must be satisfied: in, This represents the k-th factory coordination group; This indicates the reactive power balance index of the equivalent renewable energy generating unit; This is the dead zone for reactive power balance index; Determined by the following formula: in, This indicates the adjustment amount of reactive power output of the equivalent renewable energy generating unit; , and These represent the current reactive power, lower reactive power limit, and upper reactive power limit of the equivalent renewable energy generating unit, respectively. Represents the reactive power balance index of the i-th renewable energy equivalent unit; and These are the weighting coefficients. The weighting coefficient represents the target voltage regulation of the central bus. The weighting coefficient represents the reactive power balance target of equivalent renewable energy units. This is the gain coefficient; , , and These represent the current voltage of the central bus, the voltage deviation of the central bus, the lower limit of the central bus voltage, and the upper limit of the central bus voltage, respectively. , , , and These represent the current voltage, lower voltage limit, upper voltage limit, maximum single-step adjustment, and voltage adjustment amount of the high-voltage side bus of the main transformer at the new energy power station, respectively. and These are the sensitivity matrices of the new energy equivalent generating units to the central bus and the sensitivity matrix of the new energy equivalent generating units to the high-voltage side bus of the main transformer, respectively, satisfying: Solving the quadratic programming model yields the following results: The optimization results.

4. The method according to claim 3, characterized in that, Also includes: Under the lag correction control, a quadratic programming model for the lag correction control is established and solved. The quadratic programming model expression for the lag correction control is as follows: The following constraints must be satisfied: - ≤ ≤ in, Representatives from the factory coordination team gathered. This represents the i-th factory coordination group; This indicates the reactive power balance index of the equivalent renewable energy generating unit; This is the dead zone for central bus voltage control. and These are the weighting coefficients. The weighting coefficient represents the reactive power coordination target among new energy power plants. The weighting coefficient represents the reactive power balance target of equivalent renewable energy generating units; Solving the quadratic programming model yields the following results: The optimization results.

5. The method according to claim 4, characterized in that, The calculation of the high-voltage side voltage setpoint and the reactive power setpoint at the grid connection point of the new energy power station includes: Adjustment based on reactive power output of equivalent new energy generating units Sensitivity matrix of high-voltage side bus Calculate the adjustment amount of the high-voltage side bus voltage setpoint of the new energy power station. ; For new energy power stations i, based on The adjustment amount of the high-voltage side voltage setpoint of the new energy power station i is obtained as follows: ;based on The reactive power adjustment of the renewable energy units belonging to renewable energy power station i is accumulated to obtain the reactive power setpoint adjustment of renewable energy power station i. ; Record the real-time value of the current high-voltage side bus voltage of the new energy power station i collected by the AVC master station. The collected reactive power value at the grid connection point The upper limit of the high-voltage bus voltage control for new energy power station i is set as follows: The lower limit of the high-voltage side bus voltage control is The upper limit of reactive power control at the grid connection point is The lower limit of reactive power control at the grid connection point is ; Adjustment amount based on the high-voltage side bus voltage setting value of new energy power station i The high-voltage side bus voltage setting value of new energy power station i is obtained. And perform voltage control upper and lower limit verification: like Then let ;like Then let Otherwise, keep constant; Reactive power setpoint adjustment based on new energy power station i The reactive power setpoint of the grid connection point of the new energy power station i is obtained. And perform reactive power control upper and lower limit verification: like Then let ;like Then let Otherwise, keep constant.

6. The method according to claim 5, characterized in that, Also includes: When a voltage source type power station is controlled in constant voltage control mode, the voltage setpoint received by the power station's AVC substation from the AVC master station is... Among them, for new energy power stations i, That is Data collection station grid connection point , , ,in Indicates the bus voltage value at the grid connection point. Indicates the active power value of the outgoing line from the grid connection point. Indicates the reactive power value of the outgoing line from the grid connection point; Record The voltage adjustment step size for each round, The step size for reactive power regulation in each round is given; the voltage regulation amount is calculated as follows: Then determine: like Then let The reactive power regulation is ,in For grid connection point voltage reactive power sensitivity; otherwise, maintain constant; Then further determine: if Then let Otherwise, keep Unchanged; then The reactive power regulation is used to adjust the reactive power equipment in the station to meet the voltage regulation requirements of the main station.

7. The method according to claim 6, characterized in that, Also includes: When a reactive power source type power station is controlled according to the constant reactive power control mode, the reactive power setpoint received by the power station's AVC substation from the AVC master station is... Among them, for new energy power stations i, That is Upper limit of voltage static safety domain and lower limit of voltage static safety domain The voltage control dead zone of the AVC substation is The reactive power control dead zone is ; If the voltage at the grid connection point of the new energy power station ≥ - In this control cycle, the adjustment requirement of the main station's reactive power setting target value is temporarily abandoned, and an magnetization interlocking signal is sent to the AVC main station. - To control the voltage control target; If the voltage at the grid connection point of the new energy power station ≤ + In this control cycle, the reactive power regulation target is temporarily abandoned, and a demagnetization lockout signal is sent to the AVC master station. + To control the voltage control target; like + < < - Then the AVC substation of that station will be... To achieve the control objective, the reactive power adjustment is controlled. ,right Perform verification; among which, let , , , Then determine: like > Then let = ;like < Then let = Otherwise, keep constant; Then further determine: if Then let Otherwise, keep Unchanged; then To adjust the reactive power of the equipment in the power station to meet the reactive power regulation requirements of the main station.

8. The method according to claim 7, characterized in that, Also includes: When the AVC substation of the new energy power station does not receive instructions from the AVC master station within a set time period, it switches to local control; When under local control, the AVC substation switches to constant voltage control mode and controls according to the set voltage curve; Wherein, the default setting value of the voltage obtained from the voltage curve at time T is... The voltage adjustment step size of the AVC substation in the new energy power station during the switching process of different control modes. The step size of reactive power adjustment in each round , This is the reduction factor during the switching process; the grid connection point bus voltage value is... Calculate the voltage regulation amount Then determine: like Then let Otherwise, keep constant; Calculate the reactive power regulation as follows: Then determine: like Then let Otherwise, keep Unchanged; then To regulate the reactive power of reactive power equipment within the power station; when When restoring the voltage regulation step size of the AVC substation, it is... The reactive power adjustment step size is ;when Long time greater than When switching from the new energy AVC substation to local control, the counting begins, and after N consecutive rounds of voltage regulation, the voltage regulation step size of the AVC substation is restored. The reactive power adjustment step size is .

9. The method according to claim 8, characterized in that, Also includes: When the AVC substation of the new energy power station receives the control command issued by the AVC master station again, it switches to remote control and the new energy power station is controlled according to the control mode issued by the AVC master station. During the handover process, the voltage adjustment step size of each AVC substation at this site is... The step size of reactive power adjustment in each round ; When controlling a voltage source type power station using constant voltage control mode, if Then the voltage regulation step size of the restored AVC substation is... The reactive power adjustment step size is Otherwise, keep and constant; When a reactive power source type power station is controlled according to the constant reactive power control mode, if Then the reactive power adjustment step size of the restored AVC substation is... Otherwise, keep and constant; The counting begins when switching from AVC substation to remote control, and the voltage regulation step size after M consecutive rounds of voltage regulation is [value missing]. The reactive power adjustment step size is .

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