Reactive compensation calculation method and system for new energy station

Abstract

The invention discloses a reactive compensation calculation method and system for a new energy station, and the method comprises the following steps: obtaining power demand parameters of power generation equipment, conversion equipment and auxiliary equipment in the new energy station, and estimating the complex power of each equipment according to a load characteristic model; performing power flow analysis on the power system through the admittance matrix, and calculating voltage, current and reactive power distribution of each node in the system; according to the voltage, current and reactive power distribution, determining an area needing reactive power compensation and a compensation amount; proper reactive power compensation equipment is selected, the working state of the compensation equipment is dynamically adjusted according to real-time monitoring data, and the reactive power compensation amount is optimized; the reactive power compensation strategy is continuously optimized through a feedback regulation mechanism, stable operation of the system under various working conditions is ensured, and through the method, the reactive power can be efficiently regulated, the stability of a power grid is ensured, the efficiency of new energy grid connection is improved, and the reactive power compensation effect is optimized.

Description

Technical Field

[0001] This invention relates to a method and system for calculating reactive power compensation in new energy power plants. Background Technology

[0002] In the operation of renewable energy power plants, the power grid faces complex reactive power demand and voltage stability issues due to the volatility and uncertainty of renewable energy sources such as wind and solar power. Especially under large-scale grid-connected power generation, power fluctuations generated by the power generation and conversion equipment in renewable energy power plants can easily lead to voltage fluctuations, thereby affecting the operational safety and stability of the power grid.

[0003] Traditional reactive power compensation methods typically rely on static compensation devices, such as capacitor banks or fixed reactive power compensation equipment. However, these devices cannot respond to rapid changes in the power grid in real time, resulting in unsatisfactory compensation effects, especially when renewable energy generation fluctuates significantly. Furthermore, as the scale of renewable energy power plants continues to expand, the capacity limitations and responsiveness of single compensation devices are becoming increasingly inadequate.

[0004] To address this issue, increasing research is focusing on strategies for dynamically optimizing reactive power compensation. These strategies utilize real-time monitoring and control technologies, combined with intelligent compensation devices, to achieve real-time adjustment and optimization of reactive power demand. However, current solutions still face challenges such as accurately acquiring power demand parameters under complex grid conditions, precisely calculating the voltage, current, and reactive power distribution at each node through power flow analysis, and selecting appropriate reactive power compensation devices.

[0005] Therefore, those skilled in the art need an efficient and accurate reactive power compensation calculation method that can not only dynamically optimize the reactive power compensation amount in new energy power plants, but also quickly adjust the working status of reactive power compensation equipment based on real-time monitoring data, thereby solving the voltage fluctuation problem in new energy power plants and improving the stability of the power grid and the grid connection efficiency of new energy. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by providing a reactive power compensation calculation method and system for renewable energy power plants. Through dynamic optimization of reactive power compensation strategies, combined with real-time monitoring data and precise power flow analysis, the stability of the power grid is effectively improved, and the negative impact of renewable energy power plants on the power grid is reduced. The specific solution is as follows:

[0007] In one aspect, a reactive power compensation calculation method for new energy power plants includes the following steps: obtaining power demand parameters of power generation equipment, conversion equipment, and auxiliary equipment in the new energy power plant, wherein the power demand parameters include active power, reactive power, and their power factors, and obtaining the complex power of each equipment based on the load characteristic models of the power generation equipment, conversion equipment, and auxiliary equipment; performing power flow analysis on the power generation equipment, conversion equipment, and auxiliary equipment through the admittance matrix to calculate the voltage, current, and reactive power distribution of each node in each equipment; determining the reactive power compensation area and reactive power compensation amount based on the voltage, current, and reactive power distribution; selecting the corresponding reactive power compensation equipment based on the reactive power compensation area and reactive power compensation amount; adjusting the working state of the reactive power compensation equipment based on the real-time monitoring data of the new energy power plant to dynamically optimize the reactive power compensation amount; continuously optimizing the reactive power compensation strategy based on the real-time monitoring data and feeding the reactive power compensation strategy back to the reactive power compensation equipment.

[0008] Furthermore, the load characteristic model includes a linear model or a nonlinear model; the step of obtaining the power demand parameters of the power generation equipment, conversion equipment, and auxiliary equipment in the new energy power station, wherein the power demand parameters include active power, reactive power, and their power factors, and obtaining the complex power of each equipment based on the load characteristic model of the power generation equipment, conversion equipment, and auxiliary equipment includes: estimating the load characteristic model of the power generation equipment, conversion equipment, and auxiliary equipment in the new energy power station through historical data of the equipment or the characteristic curve of the equipment itself, wherein the power generation equipment and conversion equipment use a linear model, and the auxiliary equipment uses a nonlinear model; obtaining the power demand parameters of the power generation equipment, conversion equipment, and auxiliary equipment in the new energy power station through monitoring equipment; through the load characteristic model, the operating status and demand of different equipment can be more accurately reflected; by utilizing the historical data of the equipment or the characteristic curve of the equipment itself, power demand prediction can be made according to the characteristics of different equipment, thereby improving the accuracy and adaptability of the model.

[0009] Furthermore, the step of performing power flow analysis on the power generation equipment, conversion equipment, and auxiliary equipment using the admittance matrix to calculate the voltage, current, and reactive power distribution of each node in each equipment includes: constructing an admittance matrix based on the topology of the new energy power station, and setting voltage and power boundary conditions; using the admittance matrix and boundary conditions, iteratively calculating the voltage, current, and reactive power distribution of each node in the system by solving the power balance equation; traditional reactive power compensation methods ignore the specific voltage and reactive power distribution of each node in the power grid, resulting in unsatisfactory compensation effects. However, through power flow analysis, this invention can accurately calculate the electrical parameters of each node, ensuring that reactive power compensation can be targeted and avoiding over-compensation or under-compensation.

[0010] Furthermore, the step of determining the reactive power compensation area and the amount of reactive power compensation based on the voltage, current, and reactive power distribution includes: performing voltage amplitude analysis, sensitivity analysis, and critical reactive power analysis on the voltage, current, and reactive power distribution to identify areas or nodes with low voltage amplitudes, or areas or nodes sensitive to reactive power changes; and calculating the required reactive power compensation amount based on the analysis results. This invention not only relies on static calculations but also considers the sensitivity of voltage and reactive power to system stability, thereby more effectively improving the voltage stability of the system.

[0011] Furthermore, the reactive power compensation equipment includes a fixed compensation device, an adjustable compensation device, and a hybrid compensation device; thus avoiding the problem of insufficient or excessive reactive power compensation caused by improper equipment selection.

[0012] Furthermore, the step of adjusting the working state of the reactive power compensation equipment and dynamically optimizing the reactive power compensation amount based on the real-time monitoring data of the new energy power station includes: collecting the operating data of the new energy power station, wherein the operating data is updated every 5 seconds, and the operating data includes power generation data, load data and local weather data; dynamically optimizing the reactive power compensation amount based on the operating data through nonlinear fuzzy control or PID control; and combining nonlinear fuzzy control or PID control algorithms to dynamically optimize the reactive power compensation amount to meet the real-time needs of the power grid, solving the problem that traditional static compensation equipment cannot quickly respond to changes in the power grid state, and ensuring that the compensation equipment can adapt to changes in power grid load and power generation in real time.

[0013] Furthermore, the step of continuously optimizing the reactive power compensation strategy based on real-time monitoring data and feeding the reactive power compensation strategy back to the reactive power compensation equipment includes: continuously optimizing the reactive power compensation strategy based on real-time monitoring data updated every 100 milliseconds. Through continuous feedback and optimization of real-time monitoring data, the reactive power compensation strategy can adaptively adjust the compensation amount and compensation method to cope with different operating conditions and emergencies, avoiding the voltage instability or reactive power fluctuation problems caused by the failure to adjust the compensation strategy in a timely manner in traditional methods.

[0014] On the other hand, a reactive power compensation calculation system for new energy power plants includes: a power demand parameter module for acquiring power demand parameters of power generation equipment, conversion equipment, and auxiliary equipment; a power flow analysis module for performing power flow analysis and calculating voltage, current, and reactive power distribution; a compensation area determination module for determining the compensation area and compensation amount; an equipment selection module for selecting suitable reactive power compensation equipment; a real-time adjustment module for dynamically adjusting the operating status of the reactive power compensation equipment based on real-time data; a continuous optimization module for continuously optimizing the reactive power compensation strategy; and a feedback adjustment module for feeding back the optimized compensation strategy to the equipment.

[0015] Beneficial effects: Through precise power flow analysis and reactive power sensitivity analysis, this invention can accurately identify the areas in the power grid that need compensation and dynamically adjust the reactive power compensation amount according to actual needs. Compared with traditional static compensation equipment, the dynamic adjustment mechanism of this invention can respond to system fluctuations in real time, ensuring that the compensation effect can be optimized under various operating conditions and avoiding the problems of over-compensation or under-compensation.

[0016] By utilizing real-time monitoring data and intelligent control algorithms, this invention can quickly adjust the working status of reactive power compensation equipment according to the actual operation of the power grid, achieving rapid and accurate reactive power compensation. This significantly improves the grid connection efficiency of new energy power plants, reduces the impact of voltage fluctuations on the power grid, and effectively enhances the stability of the power grid. It not only improves the operational safety of the power grid but also enhances the grid connection efficiency of new energy sources and the power grid's adaptability to fluctuations in new energy sources, thus realizing the stable grid connection of large-scale renewable energy. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a reactive power compensation calculation method for new energy power plants.

[0018] Figure 2 This is a schematic diagram of a reactive power compensation calculation system for new energy power plants;

[0019] In the diagram: 100, Power Demand Parameter Module; 200, Power Flow Analysis Module; 300, Compensation Area Determination Module; 400, Equipment Selection Module; 500, Real-time Adjustment Module; 600, Continuous Optimization Module. Detailed Implementation

[0020] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0021] Please refer to Figure 1-2This paper provides a reactive power compensation calculation method for new energy power plants, comprising the following steps: obtaining power demand parameters of power generation equipment, conversion equipment, and auxiliary equipment in the new energy power plant, including active power, reactive power, and their power factors; obtaining the complex power of each equipment based on the load characteristic models of the power generation equipment, conversion equipment, and auxiliary equipment; performing power flow analysis on the power generation equipment, conversion equipment, and auxiliary equipment through the admittance matrix to calculate the voltage, current, and reactive power distribution of each node in each equipment; determining the reactive power compensation area and reactive power compensation amount based on the voltage, current, and reactive power distribution; selecting the corresponding reactive power compensation equipment based on the reactive power compensation area and reactive power compensation amount; adjusting the working state of the reactive power compensation equipment based on the real-time monitoring data of the new energy power plant to dynamically optimize the reactive power compensation amount; continuously optimizing the reactive power compensation strategy based on the real-time monitoring data and feeding the reactive power compensation strategy back to the reactive power compensation equipment.

[0022] The load characteristic model includes linear or nonlinear models. The steps for obtaining power demand parameters for power generation equipment, conversion equipment, and auxiliary equipment in the renewable energy power station, including active power, reactive power, and their power factors, and obtaining the complex power of each device based on the load characteristic models, include: estimating the load characteristic models of the power generation equipment, conversion equipment, and auxiliary equipment in the renewable energy power station using historical data or the characteristic curves of the equipment itself, where linear models are used for power generation and conversion equipment, and nonlinear models are used for auxiliary equipment; obtaining the power demand parameters of the power generation equipment, conversion equipment, and auxiliary equipment in the renewable energy power station through monitoring equipment; and performing power flow analysis on the power generation equipment, conversion equipment, and auxiliary equipment using the admittance matrix to calculate the voltage, current, and reactive power distribution of each node in each device, including: constructing the admittance matrix based on the topology of the renewable energy power station, setting voltage and power boundary conditions; and using the admittance matrix and boundary conditions, iteratively calculating the voltage, current, and reactive power distribution of each node in the system by solving the power balance equation. The distribution of reactive power; the steps to determine the area and amount of reactive power compensation required based on voltage, current, and reactive power distribution include: performing voltage amplitude analysis, sensitivity analysis, and critical reactive power analysis on voltage, current, and reactive power distribution to identify areas or nodes with low voltage amplitude, or areas or nodes sensitive to reactive power changes; calculating the required reactive power compensation amount based on the analysis results; reactive power compensation equipment includes fixed compensation devices, adjustable compensation devices, and hybrid compensation devices; the steps to dynamically optimize the reactive power compensation amount by adjusting the working state of the reactive power compensation equipment based on real-time monitoring data of the renewable energy power plant include: collecting operating data of the renewable energy power plant, where the operating data is updated every 5 seconds, and the operating data includes power generation data, load data, and local weather data; dynamically optimizing the reactive power compensation amount based on the operating data through nonlinear fuzzy control or PID control; the steps to continuously optimize the reactive power compensation strategy based on real-time monitoring data and feed the reactive power compensation strategy back to the reactive power compensation equipment include: continuously optimizing the reactive power compensation strategy based on real-time monitoring data updated every 100 milliseconds.

[0023] A reactive power compensation calculation system for new energy power plants is also provided, characterized by comprising: a power demand parameter module 100 for acquiring power demand parameters of power generation equipment, conversion equipment, and auxiliary equipment; a power flow analysis module 200 for performing power flow analysis and calculating voltage, current, and reactive power distribution; a compensation area determination module 300 for determining the compensation area and compensation amount; an equipment selection module 400 for selecting suitable reactive power compensation equipment; a real-time adjustment module 500 for dynamically adjusting the operating status of the reactive power compensation equipment based on real-time data; a continuous optimization module 600 for continuously optimizing the reactive power compensation strategy; and a feedback adjustment module for feeding back the optimized compensation strategy to the equipment.

[0024] For clarity, the following examples will be used to provide a detailed description.

[0025] Each wind turbine in the wind farm is a 3MW wind turbine, and each inverter is a 1MW photovoltaic inverter. The substation is a 110kV main substation. Sensors are installed in the above equipment to collect the active power, reactive power and power factor of each device in real time.

[0026] S1: The power demand parameter module 100 obtains the following power demand parameters for the wind turbine: active power 2.5MW, reactive power 0.8MVAr, and power factor 0.95. Based on historical operating data and the wind turbine's characteristic curve, a linear load model is used to estimate the load characteristic model. The specific method is as follows: Based on the relationship between the power factor and active and reactive power, the complex power S of the wind turbine is calculated. Based on the load characteristic model of the wind turbine, the load characteristics of the wind turbine are calculated through historical operating data. By linearly fitting the historical data, the load characteristic function can be obtained, Q=f(P)=aP+b, where a and b are coefficients obtained by data fitting and are used to calculate the reactive power demand of the wind turbine under different loads.

[0027] S2: The power flow analysis module 200 constructs the admittance matrix based on the topology of the new energy power station and sets boundary conditions for voltage and power. Assuming the wind farm contains multiple nodes connected to the power generation equipment, conversion equipment, and substation network, an example of the admittance matrix is ​​as follows: The power balance equation is used to iteratively calculate voltage, current, and reactive power distribution to obtain the voltage stability and reactive power demand of each node; the admittance matrix Y is... Then, the voltage, current, and reactive power distribution at each node are calculated using the power balance equation. Where i is the node number, V i node voltage To obtain the admittance of the complex conjugate, the equation is solved iteratively to obtain the voltage and reactive power distribution at each node. The calculated values ​​are: node A, voltage 1.02, reactive power 0.5MVAr; node B, voltage 1.00, reactive power 1.2MVAr; node C, voltage 0.98, reactive power 0.9MVAr. The voltage at node C, obtained through iterative calculation, is V. C =0.98pu, reactive power is Q C =0.9MVAr, thus determining that the node needs compensation;

[0028] S3: The compensation area determination module 300 identifies node C, a region with a low voltage amplitude, based on the power flow analysis results. The voltage amplitude of node C is 0.98, which is lower than the standard voltage value. Therefore, it is determined that this region needs reactive power compensation, and the compensation amount is calculated to be 0.6MVAr.

[0029] S4: The equipment selection module 400 selects STATCOM as the compensation device based on the reactive power compensation amount and the power grid stability requirements of the substation, and configures its capacity to 2MVAr to cope with the fluctuation of reactive power.

[0030] S5: The real-time adjustment module 500 dynamically adjusts the working status of the compensation equipment by monitoring data in real time, as follows: the real-time data acquisition frequency is changed to update once every 5 seconds, and the reactive power output of STATCOM is adjusted by nonlinear fuzzy control according to voltage fluctuations and power flow changes. When the current voltage fluctuation is large, the reactive power output of STATCOM is adjusted to 1.2MVAr.

[0031] S6: When the wind farm generates a large amount of electricity, the continuous optimization module 600 dynamically optimizes the compensation amount through the PID control strategy to reduce the impact on the power grid. When the power generation is large, the optimized compensation amount is calculated to be 1.5MVAr. The feedback regulation block feeds back the continuously optimized reactive power compensation strategy to the STATCOM device to ensure that the equipment can maintain the best working state under various operating conditions, thereby achieving accurate reactive power compensation.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for calculating reactive power compensation in new energy power plants, characterized in that, Includes the following steps: The system acquires power demand parameters for power generation equipment, conversion equipment, and auxiliary equipment in the renewable energy power plant. These parameters include active power, reactive power, and their power factors. The complex power of each device is obtained based on its load characteristic model. Power flow analysis is performed on the power generation equipment, conversion equipment, and auxiliary equipment using the admittance matrix to calculate the voltage, current, and reactive power distribution at each node in each device. Based on the voltage, current, and reactive power distribution, the required reactive power compensation area and amount are determined. Corresponding reactive power compensation equipment is selected based on the compensation area and amount. The operating status of the reactive power compensation equipment is adjusted based on real-time monitoring data from the renewable energy power plant, dynamically optimizing the reactive power compensation amount. The reactive power compensation strategy is continuously optimized based on real-time monitoring data, and the strategy is fed back to the reactive power compensation equipment.

2. The reactive power compensation calculation method for new energy power plants according to claim 1, characterized in that, The load characteristic model includes a linear model or a nonlinear model; the step of obtaining the power demand parameters of the power generation equipment, conversion equipment, and auxiliary equipment in the new energy power station, wherein the power demand parameters include active power, reactive power, and their power factors, and obtaining the complex power of each equipment according to the load characteristic model of the power generation equipment, conversion equipment, and auxiliary equipment includes: estimating the load characteristic model of the power generation equipment, conversion equipment, and auxiliary equipment in the new energy power station through historical data of the equipment or the characteristic curve of the equipment itself, wherein the power generation equipment and conversion equipment use a linear model, and the auxiliary equipment uses a nonlinear model; and obtaining the power demand parameters of the power generation equipment, conversion equipment, and auxiliary equipment in the new energy power station through monitoring equipment.

3. The reactive power compensation calculation method for new energy power plants according to claim 1, characterized in that, The steps of performing power flow analysis on power generation equipment, conversion equipment, and auxiliary equipment using the admittance matrix, and calculating the voltage, current, and reactive power distribution of each node in each equipment, include: constructing the admittance matrix based on the topology of the new energy power station, setting voltage boundary conditions and power boundary conditions; and using the admittance matrix and boundary conditions, iteratively calculating the voltage, current, and reactive power distribution of each node in the system by solving the power balance equation.

4. The reactive power compensation calculation method for new energy power plants according to claim 1, characterized in that, The step of determining the reactive power compensation area and reactive power compensation amount based on the voltage, current and reactive power distribution includes: performing voltage amplitude analysis, sensitivity analysis and critical reactive power analysis on the voltage, current and reactive power distribution to identify areas or nodes with low voltage amplitude, or areas or nodes sensitive to reactive power changes; and calculating the required reactive power compensation amount based on the analysis results.

5. The reactive power compensation calculation method for new energy power plants according to claim 1, characterized in that, The reactive power compensation equipment includes a fixed compensation device, an adjustable compensation device, and a hybrid compensation device.

6. The reactive power compensation calculation method for new energy power plants according to claim 1, characterized in that, The step of adjusting the working status of the reactive power compensation equipment and dynamically optimizing the reactive power compensation amount based on the real-time monitoring data of the new energy power station includes: collecting the operating data of the new energy power station, wherein the operating data is updated every 5 seconds, and the operating data includes power generation data, load data and local weather data; and dynamically optimizing the reactive power compensation amount based on the operating data through nonlinear fuzzy control or PID control.

7. The reactive power compensation calculation method for new energy power plants according to claim 1, characterized in that, The step of continuously optimizing the reactive power compensation strategy based on real-time monitoring data and feeding the reactive power compensation strategy back to the reactive power compensation device includes: continuously optimizing the reactive power compensation strategy based on real-time monitoring data updated every 100 milliseconds.

8. A reactive power compensation calculation system for new energy power plants, characterized in that, include: The power demand parameter module is used to obtain the power demand parameters of power generation equipment, conversion equipment and auxiliary equipment; the power flow analysis module is used to perform power flow analysis and calculate voltage, current and reactive power distribution. The compensation area determination module is used to determine the compensation area and the compensation amount; The equipment selection module is used to select suitable reactive power compensation equipment; the real-time adjustment module is used to dynamically adjust the working status of the reactive power compensation equipment based on real-time data. The continuous optimization module is used to continuously optimize the reactive power compensation strategy; the feedback adjustment module is used to feed back the optimized compensation strategy to the equipment.

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