AVC combined control method for water-light combined operation

Abstract

The invention discloses an AVC (Automatic Voltage Control) combined control method for water-light combined operation, which is used for jointly controlling a hydropower station AVC and a photovoltaic power station AVC and adjusting the target bus voltage of a water-light combined operation system. Comprising a water-light combined operation AVC master station reactive power distribution calculation method, a hydropower station AVC reactive power distribution calculation method and a photovoltaic power station AVC reactive power distribution calculation method. The water-light combined operation AVC master station calculates the total reactive power regulation quantity of the system according to the voltage reactive power relation of the target bus through the difference between the measured voltage value of the target bus and the voltage instruction value of the target bus, and then calculates the reactive power instruction of the hydropower station, the reactive power instruction of the SVG and the reactive power instructions of all photovoltaic power generation units. And the hydropower station AVC calculates the reactive power output set value of the hydroelectric generating set according to the corresponding reactive power distribution principle, and adjusts the reactive power output of the hydroelectric generating set. And the photovoltaic power station AVC calculates the reactive power output set value of the photovoltaic power generation unit according to the corresponding reactive power distribution principle, and adjusts the reactive power output of the SVG and the photovoltaic power generation unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of voltage control, and in particular relates to an AVC joint control method for water-photovoltaic joint operation. Background Art

[0002] In recent years, as the importance of environmental protection and energy security has become increasingly prominent, photovoltaic power generation, as a clean and renewable energy source, has become an important way to optimize the energy structure and achieve green and low-carbon transformation. my country is rich in solar energy resources and has good development prospects. In recent years, the installed capacity of domestic photovoltaic power generation grid-connected has grown rapidly, and the development momentum is very rapid. However, since photovoltaic power generation is affected by weather factors such as temperature and light, its output is random, volatile, and intermittent.

[0003] In order to improve the level of photovoltaic power generation, photovoltaic power generation units usually work in the maximum power point tracking mode, and the power factor is 1. This makes the photovoltaic power station insufficient in reactive support for the power system after grid connection. In order to ensure the stable and reliable operation of the system, the reactive power of the photovoltaic power generation unit must be fully utilized. The reactive output range of the photovoltaic power generation unit is limited by the capacity of the photovoltaic inverter and the power factor. This also leads to the reactive output of the photovoltaic power generation unit may have the characteristics of volatility and intermittency along with the active output. On the other hand, as a kind of renewable energy, hydropower stations are also an effective way to achieve the dual carbon goals. Hydropower units start quickly, are flexible to adjust, and have strong adjustment capabilities. In addition, hydropower units are equipped with automatic excitation systems, and the speed of magnetization and demagnetization can be completed within tens of milliseconds, so the terminal voltage can also be adjusted quickly. Therefore, the hydropower station and the photovoltaic power station can be operated together to coordinate the reactive output of the hydropower station and the photovoltaic power station to ensure the stability of the voltage of the water-light complementary system. Summary of the invention

[0004] In order to solve the technical problem of jointly regulating voltage and reactive power of hydropower stations and photovoltaic power stations existing in the background technology, the present invention aims to provide an AVC joint control method for joint operation of water and light, which can coordinate the AVC systems of the hydropower station and the AVC systems of the photovoltaic power station to achieve joint control of the target bus voltage.

[0005] In order to solve the technical problem, the technical solution of the present invention is:

[0006] An AVC joint control method for water-light joint operation, the method comprising:

[0007] The reactive power setting values ​​of the hydropower station, SVG and photovoltaic power generation units are calculated through the AVC of the joint operation of water and light. Then the reactive power setting value of the hydropower unit is calculated through the AVC of the hydropower station. The reactive power setting value of each photovoltaic power generation unit is calculated through the AVC of the photovoltaic power station, and instructions are sent to the reactive power supply to adjust the reactive output of the reactive power supply so that the target bus voltage reaches the adjustment dead zone range of the voltage instruction.

[0008] Furthermore, the reactive power setting values ​​of the hydropower station, SVG and photovoltaic power generation unit are calculated, including:

[0009] S 1: Establish the voltage and reactive power regulation model of the system according to the voltage and reactive power characteristics of the target bus during the combined operation of water and photovoltaic power;

[0010] S2: According to the actual measured value of the bus voltage, determine whether the bus voltage is within the regulation dead zone, and calculate the total reactive power regulation value ΔQ according to the difference between the actual measured value of the bus voltage and the command value of the bus voltage. 总 ;

[0011] S3: Based on the total reactive power regulation ΔQ 总 , calculate the reactive regulation ΔQ of the hydropower station and the static VAR generator SVG 水 and ΔQsvG, and the total reactive power regulation of all photovoltaic power generation units ΔQ 光 ;

[0012] S4: According to the reactive power regulation ΔQ of the hydropower station 水 and the current reactive power output value Q of the hydropower station 水 , calculate the reactive power setting value of the hydropower station According to the total reactive power regulation of all photovoltaic power generation units ΔQ 光 And the current total reactive power output value Q of all photovoltaic power generation units 光 , calculate the total reactive power setting value of all photovoltaic power generation units According to the reactive power regulation of SVG ΔQ SVG and SVG's current reactive power output value Q SVG , calculate the reactive power setting value of SVG

[0013] Furthermore, according to the reactive power setting value of the hydropower station Calculate the reactive power setting value of the hydropower unit According to the total reactive power setting value of all photovoltaic power generation units Calculate the reactive power setting value of each photovoltaic power generation unit The instructions are sent to each unit and power generation unit. When the reactive output reaches the preset value, the target bus voltage is collected to determine whether the target bus voltage is within the regulation dead zone.

[0014] The voltage instruction may be a voltage instruction issued in real time by the upper-level dispatching AVC master station, or a set voltage curve; according to the instruction of the target bus voltage, the voltage deviation is calculated, and the total reactive power regulation is obtained according to the voltage-reactive power relationship at the target bus;

[0015] Furthermore, considering the relationship between the voltage and reactive power at the target bus under different active output conditions of the hydropower station and the photovoltaic power station, a voltage and reactive power regulation model is established.

[0016] Further, in step S2:

[0017] The bus voltage command value is obtained by using the command value issued by the upper-level dispatching AVC master station or according to a pre-set voltage curve;

[0018] Total reactive power regulation ΔQ 总 The calculation is completed in the AVC main station of the water-light joint operation, and the calculation method is as follows:

[0019] ΔQ=-HΔU(4)

[0020] Where ΔU is a column vector, and each row represents the voltage deviation at a node. The value of the row where the node 220 kV bus is located in ΔU is the difference between the current voltage and the dispatch instruction, and the values ​​of the remaining rows are zero. H is the voltage-reactive sensitivity matrix based on the current system state parameters.

[0021] Furthermore, the reactive power regulation of the hydropower station and the total reactive power regulation of all photovoltaic power generation units are allocated according to equal proportion and equal reactive power margin; during the joint operation of water and light, the reactive power of the hydropower units and photovoltaic power generation units is used first, that is, when the reactive power of all hydropower units and all photovoltaic power generation units is exhausted, the reactive power of SVG is used.

[0022] Furthermore, the reactive power setting value of the hydropower station It is sent from the AVC main station of the combined water and light operation to the AVC of the hydropower station.

[0023] Furthermore, the reactive power setting value of the hydropower unit The calculation methods include: the reactive power distribution principle among the hydropower units is selected as the equal proportion principle or the equal reactive power margin principle; the reactive power regulation amount of each hydropower unit is calculated in the AVC of the hydropower station;

[0024] When the reactive power margin ratio is used for allocation, the reactive power margin refers to the difference between the current reactive power output of the generator set and the reactive power limit value. When the reactive power needs to be increased, the reactive power limit value takes the upper limit; when the reactive power needs to be reduced, the reactive power limit value takes the lower limit.

[0025] The reactive power limit of a hydropower unit is related to the unit itself and the power factor. The reactive power limit of a hydropower unit is calculated as follows:

[0026]

[0027]

[0028] In the formula, is the maximum reactive power that the hydropower unit can generate; P g The current active power output of the hydropower unit; The minimum power factor of the hydropower unit allowed for dispatch.

[0029] Furthermore, the reactive power setting value of the SVG and reactive power setting values ​​of all photovoltaic power generation units It is sent from the AVC main station of the combined operation of water and light to the AVC of the photovoltaic power station.

[0030] Furthermore, the reactive power setting value of the photovoltaic power generation unit is The calculation methods include:

[0031] The reactive power distribution principle among the photovoltaic power generation units is selected as the equal proportion principle or the equal reactive power margin principle, and the reactive power regulation of each photovoltaic power generation unit is calculated in the photovoltaic power station AVC;

[0032] When the reactive power margin ratio is used for allocation, the reactive power margin refers to the difference between the current reactive power output of the generator set and the reactive power limit value. When the reactive power needs to be increased, the reactive power limit value takes the upper limit; when the reactive power needs to be reduced, the reactive power limit value takes the lower limit.

[0033] The reactive power limit of the photovoltaic power generation unit is related to the inverter capacity and the power factor. The reactive power limit of the photovoltaic power generation unit is calculated as follows:

[0034]

[0035]

[0036] In the formula, S inv is the capacity of the inverter; P p is the current active power output of the photovoltaic power generation unit; The minimum power factor allowed for a photovoltaic power generation unit is 0.95 according to the national standard.

[0037] The reactive power setting value of the photovoltaic power generation unit is the total reactive power setting value of a single photovoltaic power generation unit.

[0038] The reactive power distribution calculation method is as follows: when hydropower and photovoltaic power are in joint operation, the reactive power of hydropower units and photovoltaic power generation units is used preferentially. The reactive power regulation of the hydropower station and the total reactive power regulation of all photovoltaic power generation units can be distributed according to equal proportion and equal reactive power margin. When the reactive power of all hydropower units and all photovoltaic power generation units is exhausted, the reactive power of SVG is used.

[0039] Wherein, the reactive power source includes a hydropower unit, an SVG and a photovoltaic power generation unit.

[0040] "Instructions" mainly refer to control signals sent to hydropower units and photovoltaic power generation units. These instructions contain specific reactive power set values, which are used to guide the units and power generation units to adjust their reactive output to meet the voltage and reactive power requirements of the system. Specifically, these instructions can include the following:

[0041] 1. Reactive power setting value command

[0042] Reactive power setting value command of hydropower unit:

[0043] The AVC of the hydropower station is based on the calculated reactive power setting value It is subdivided into reactive output setting values ​​of each unit And sent to each hydropower unit through the system's control interface. The command is similar to:

[0044] Command type: Reactive output setting

[0045] Instruction content: Specify the reactive power setting value of a hydropower unit

[0046] Photovoltaic power generation unit reactive power setting value command:

[0047] After calculating the total reactive power setting value of all photovoltaic power generation units After that, it is further divided into the reactive power setting value of each photovoltaic power generation unit. The instructions usually include:

[0048] Command type: Reactive output setting

[0049] Instruction content: Specify the reactive power setting value of a photovoltaic power generation unit

[0050] 2. Execution and confirmation of instructions

[0051] Instructions issued:

[0052] The instructions are sent to the controllers of each unit and power generation unit through the automatic control system. After receiving the instructions, the controller starts to adjust its reactive power output.

[0053] 3. Monitoring and feedback

[0054] Voltage collection and judgment:

[0055] After the reactive power output adjustment is completed, the system will monitor the target bus voltage in real time and determine whether the current voltage is within the preset regulation dead zone. This can be achieved through the following process:

[0056] Collect current voltage value

[0057] This voltage value is compared with the set voltage command to check whether it is within the allowable dead band range (for example, it can be defined as ±0.3kV of the target voltage or other reasonable limits).

[0058] 4. Control feedback

[0059] Adjustment command: If the target bus voltage is not within the dead zone, the system will need to recalculate the reactive power set value and repeat the above steps to adjust the reactive power output to ensure voltage stability.

[0060] Compared with the prior art, the advantages of the present invention are:

[0061] Efficient reactive power distribution: The present invention optimizes the distribution of reactive power among different power generation units by accurately calculating the reactive setting values ​​of the hydropower station, SVG and photovoltaic power generation units, ensuring that each device performs at its best, thereby improving the overall stability of the system.

[0062] Enhance the stability of the power system: By comprehensively considering the impact of the active output of hydropower stations and photovoltaic power stations on the target bus voltage, the present invention can effectively coordinate multiple power generation methods, reduce the risks of power grids due to fluctuations in renewable energy, and enhance the anti-interference ability of the power system.

[0063] Real-time dynamic adjustment capability: The present invention adopts real-time monitoring of the target bus voltage and reactive power, and timely adjusts the set value through the feedback mechanism, so that the system can quickly respond to changes in the power grid and improve the reliability of power supply.

[0064] Strong adaptability: The present invention can flexibly adapt to the grid demand under different operating conditions, whether it is load changes or fluctuations in renewable energy power generation, and can be effectively adjusted, with strong adaptability.

[0065] Improve the competitiveness of the power market: Through efficient voltage and reactive power control, the present invention provides a more stable and reliable power supply to the power market, thereby enhancing the competitiveness of the market.

[0066] In summary, the present invention combines the advantages of hydropower and photovoltaics through an innovative AVC joint control method, improves the overall performance and reliability of hydropower and photovoltaic joint operation, and provides important technical support for the development of future power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 , is a schematic diagram of the water-light joint operation structure;

[0068] Figure 2 , is a schematic diagram of the AVC connection structure for the joint operation of water and light;

[0069] Figure 3 , AVC flow chart for the joint operation of water and light;

[0070] Figure 4 , AVC flow chart of hydropower station

[0071] Figure 5 , is the AVC flow chart of photovoltaic power station;

[0072] Figure 6 , is the total active output variation curve of all photovoltaic power generation units in the photovoltaic power station;

[0073] Figure 7 , is the voltage curve diagram of 220kV busbar in combined operation of water and photovoltaic;

[0074] Figure 8 , which are the reactive power output curves of all hydropower units, all photovoltaic power generation units, and SVG. DETAILED DESCRIPTION

[0075] The specific implementation mode of the present invention is described below in conjunction with embodiments:

[0076] It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0077] At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0078] Embodiment 1:

[0079] This embodiment provides an AVC joint control method for the joint operation of water and photovoltaic power, which includes calculating the reactive power regulation of the hydropower station, SVG and photovoltaic power generation unit, coordinating the AVC of the hydropower station and the AVC of the photovoltaic power station, and jointly adjusting the target bus voltage of the joint operation system of water and photovoltaic power.

[0080] In this embodiment, the water-solar joint operation system composed of the Bosi photovoltaic power station and the Luogu hydropower station is used as a test case for the AVC joint control method of the water-solar joint operation. The active output and voltage command between 7:00 and 17:00 on a certain day are taken as the example operation data. The active output of a single hydropower unit of the Luogu hydropower station remains unchanged at 40MW, and the total active output change curve of all photovoltaic power generation units in the photovoltaic power station is as follows: Figure 6 shown.

[0081] like Figure 1 As shown in the figure, the hydropower-solar joint operation system consists of a hydropower station and a photovoltaic power station. There are two hydropower units inside the hydropower station, and each hydropower unit is connected to the 220kV bus of the hydropower station through a 220kV / 10.5kV step-up transformer. There are four collector lines and one SVG inside the photovoltaic power station. The four collector lines and one SVG are all connected to the 35kV bus of the photovoltaic power station, and then connected to the 220kV bus of the hydropower station through a 220kV / 35kV main transformer.

[0082] like Figure 2 As shown in the figure, there are three AVC systems in the hydro-solar joint operation system. The hydro-solar joint operation AVC master station is connected to the provincial dispatching AVC master station through a telecontrol device. The hydropower station AVC and the photovoltaic power station AVC are respectively connected to the hydro-solar joint operation AVC master station. The voltage regulation dead zone of the hydro-solar joint operation system AVC is 0.3kV.

[0083] like Figure 3 As shown, the AVC joint control method for the combined operation of water and light is operated according to the following process: the bus voltage value is collected, the bus voltage setting value is read, and the AVC main station of the combined operation of water and light calculates the total reactive power regulation of the combined operation system of water and light according to the voltage deviation, and then calculates the reactive power regulation of the hydropower station, the reactive power regulation of all photovoltaic power generation units, and the reactive power regulation of SVG according to the corresponding allocation principle. Then, according to the current reactive output, the reactive setting value of the hydropower station, the reactive setting value of all photovoltaic power generation units, and the reactive setting value of SVG are calculated. The AVC main station of the combined operation of water and light sends the reactive setting value of the hydropower station to the AVC of the hydropower station, and sends the reactive setting value of all photovoltaic power generation units and the reactive setting value of SVG to the AVC of the photovoltaic power station.

[0084] like Figure 4 As shown, after the hydropower station AVC receives the reactive power setting value instruction of the hydropower station, it calculates the reactive power setting value of each hydropower unit according to the corresponding allocation principle, and then adjusts the excitation system of the hydropower unit (through the DCS device) to make the reactive output of the hydropower unit reach the set value.

[0085] like Figure 5As shown in the figure, after receiving the total reactive power setting value of all photovoltaic power generation units and the reactive power setting value instruction of SVG, the photovoltaic power station AVC first calculates the reactive power setting value of each photovoltaic power generation unit according to the corresponding allocation principle, and then issues instructions to adjust the reactive output of each photovoltaic unit and SVG so that the reactive output of each device reaches the set value.

[0086] It can be understood that in the AVC main station of the hydro-solar combined operation, the total reactive power regulation amount is obtained based on the voltage-reactive power correlation at the busbar of the hydro-solar combined operation system, that is, formula (1), but the total reactive power regulation amount can also be determined by the operating personnel based on experience.

[0087] It is understandable that when the reactive power is allocated according to the equal reactive power margin ratio, the reactive power margin refers to the difference between the current reactive power output of the generator set and the reactive power limit. When the reactive power needs to be increased, the reactive power limit takes the upper limit; when the reactive power needs to be reduced, the reactive power limit takes the lower limit.

[0088] It is understandable that the reactive power limit of a hydropower unit is related to the unit itself and the power factor. The reactive power limit of a hydropower unit is calculated as follows:

[0089]

[0090] In the formula, is the maximum reactive power that the hydropower unit can generate; P g The current active power output of the hydropower unit; The minimum power factor of the hydropower unit allowed for dispatch.

[0091] It is understandable that the reactive power limit of a photovoltaic power generation unit is related to the inverter capacity and the power factor. The reactive power limit of a photovoltaic power generation unit is calculated as follows:

[0092]

[0093]

[0094] In the formula, S inv is the capacity of the inverter; P p is the current active power output of the photovoltaic power generation unit; The minimum power factor allowed for a photovoltaic power generation unit is 0.95 according to the national standard.

[0095] Figure 7 This is the variation curve of 220kV bus voltage in combined operation of hydropower and photovoltaic power. Figure 8 It is the reactive power output curve of the hydropower station, the reactive power output of all photovoltaic power generation units and the reactive power output curve of SVG. Figure 7 Figure 8It can be seen that the AVC joint control method of the hydro-photovoltaic combined operation system coordinates the reactive output of the hydropower station and the photovoltaic power station, fully utilizes the reactive power of the photovoltaic power generation unit, and ensures that the voltage at the busbar of the hydro-photovoltaic combined operation system grid connection point is well consistent with the voltage command, proving that the AVC joint control method of the hydro-photovoltaic combined operation system plays a good coordination and control role.

[0096] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0097] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0098] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0099] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0100] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

[0101] Many other changes and modifications may be made without departing from the concept and scope of the present invention.It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A water-light joint operation AVC joint control method, characterized in that: The method comprises: Through the joint operation of water and light, the AVC main station calculates the reactive setting values ​​of the hydropower station, SVG and photovoltaic power generation units, and then calculates the reactive setting value of the hydropower unit through the hydropower station AVC, and calculates the reactive setting value of each photovoltaic power generation unit through the photovoltaic power station AVC, and sends instructions to the reactive power supply to adjust the reactive output of the reactive power supply so that the target bus voltage reaches the adjustment dead zone range of the voltage instruction.

2. The AVC joint control method for water-light joint operation according to claim 1 is characterized in that: Calculate reactive power setpoints for hydropower plants, SVGs and photovoltaic units, including: S1: Establish the voltage and reactive power regulation model of the system according to the voltage and reactive power characteristics of the target busbar in the combined operation of water and solar power; S2: According to the actual measured value of the bus voltage, determine whether the bus voltage is within the regulation dead zone, and calculate the total reactive power regulation value ΔQ according to the difference between the actual measured value of the bus voltage and the bus voltage command value. 总 ; S3: Based on the total reactive power regulation ΔQ 总 , calculate the reactive regulation ΔQ of the hydropower station and the static VAR generator SVG 水 and ΔQ SVG , and the total reactive power regulation of all photovoltaic power generation units ΔQ 光 ; S4: According to the reactive power regulation ΔQ of the hydropower station 水 and the current reactive power output value Q of the hydropower station 水 , calculate the reactive power setting value of the hydropower station According to the total reactive power regulation of all photovoltaic power generation units ΔQ 光 And the current total reactive power output value Q of all photovoltaic power generation units 光 , calculate the total reactive power setting value of all photovoltaic power generation units According to the reactive power regulation of SVG ΔQ SVG and SVG's current reactive power output value Q SVG , calculate the reactive power setting value of SVG 3. The AVC joint control method for water-light joint operation according to claim 2 is characterized in that: According to the reactive power setting value of the hydropower station Calculate the reactive power setting value of the hydropower unit According to the total reactive power setting value of all photovoltaic power generation units Calculate the reactive power setting value of each photovoltaic power generation unit The instructions are sent to each unit and power generation unit. When the reactive output reaches the preset value, the target bus voltage is collected to determine whether the target bus voltage is within the regulation dead zone.

4. The AVC joint control method for water-light joint operation according to claim 2 is characterized in that: Considering the relationship between voltage and reactive power at the target bus under different active output conditions of hydropower stations and photovoltaic power stations, a voltage and reactive power regulation model is established.

5. The AVC joint control method for water-light joint operation according to claim 2 is characterized in that: In step S2: The bus voltage command value is obtained by using the command value issued by the upper-level dispatching AVC master station or according to a pre-set voltage curve; Total reactive power regulation ΔQ 总 The calculation is completed in the AVC main station of the water-light joint operation, and the calculation method is as follows: ΔQ=-HΔU(1) Where ΔU is a column vector, and each row represents the voltage deviation at a node. The value of the row where the node 220 kV bus is located in ΔU is the difference between the current voltage and the dispatch instruction, and the values ​​of the remaining rows are zero. H is the voltage-reactive sensitivity matrix based on the current system state parameters.

6. The AVC joint control method for water-light joint operation according to claim 2 is characterized in that: The reactive power regulation of the hydropower station and the total reactive power regulation of all photovoltaic power generation units are allocated according to equal proportion and equal reactive power margin; when the hydropower and photovoltaic power are operated together, the reactive power of the hydropower units and photovoltaic power generation units is used first, that is, when the reactive power of all hydropower units and all photovoltaic power generation units is exhausted, the reactive power of SVG is used.

7. The AVC joint control method for water-light joint operation according to claim 2 is characterized in that: Reactive power setting value of the hydropower station It is sent from the AVC main station of the combined water and light operation to the AVC of the hydropower station.

8. The AVC joint control method for a water-light joint operation system according to claim 2 is characterized in that: The reactive power setting value of the hydropower unit The calculation methods include: the reactive power distribution principle among the hydropower units is selected as the equal proportion principle or the equal reactive power margin principle; the reactive power regulation amount of each hydropower unit is calculated in the AVC of the hydropower station; When the reactive power margin ratio is used for allocation, the reactive power margin refers to the difference between the current reactive power output of the generator set and the reactive power limit value. When the reactive power needs to be increased, the reactive power limit value takes the upper limit; when the reactive power needs to be reduced, the reactive power limit value takes the lower limit. The reactive power limit of a hydropower unit is related to the unit itself and the power factor. The reactive power limit of a hydropower unit is calculated as follows: In the formula, is the maximum reactive power that the hydropower unit can generate; P g The current active power output of the hydropower unit; The minimum power factor of the hydropower unit allowed for dispatch.

9. The AVC joint control method of the water-light joint operation system according to claim 2 is characterized in that: The reactive power setting value of the SVG and reactive power setpoints for all photovoltaic power generation units It is sent from the AVC main station of the combined hydro-photovoltaic operation to the AVC of the photovoltaic power station.

10. The AVC joint control method for water-light joint operation according to claim 3, characterized in that: The reactive power setting value of the photovoltaic power generation unit The calculation methods include: The reactive power distribution principle among the photovoltaic power generation units is selected as the equal proportion principle or the equal reactive power margin principle, and the reactive power regulation amount of each photovoltaic power generation unit is calculated in the photovoltaic power station AVC; When the reactive power margin ratio is used for allocation, the reactive power margin refers to the difference between the current reactive power output of the generator set and the reactive power limit value. When the reactive power needs to be increased, the reactive power limit value takes the upper limit; when the reactive power needs to be reduced, the reactive power limit value takes the lower limit. The reactive power limit of the photovoltaic power generation unit is related to the inverter capacity and the power factor. The reactive power limit of the photovoltaic power generation unit is calculated as follows: In the formula, S inv is the capacity of the inverter; P p is the current active power output of the photovoltaic power generation unit; The minimum power factor allowed for a photovoltaic power generation unit is 0.95 according to the national standard.

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