Methods, systems, equipment and storage media for reactive power loss compensation in new energy power plant lines

Abstract

This invention relates to the field of power quality technology for power plants, and particularly to a method, system, equipment, and storage medium for compensating reactive power loss in new energy power plant lines. The method includes the following steps: S1, acquiring the length, inductance, capacitance, and reactive power loss, current, and voltage under different active power conditions of the high-voltage transmission line; S2, performing offline fitting on the data acquired in S1 to obtain the real-time reactive power loss of the transmission line; S3, calculating real-time reactive power compensation using the real-time reactive power loss. The reactive power loss compensation method for new energy power plant lines adopted in this invention utilizes data from the opposite station and the new energy power plant design specifications to obtain the calculation method for reactive power loss in the transmission line, achieving real-time compensation for line reactive power loss and avoiding the impact of line loss on power factor assessment.

Description

Technical Field

[0001] This invention relates to the field of power quality technology for power plants, specifically to a method, system, equipment, and storage medium for compensating reactive power loss in new energy power plant lines. Background Technology

[0002] With the rapid development of modern power grids, the large-scale integration of new energy sources, the widespread application of AC / DC grid connection, and nonlinear and impulsive loads such as high-voltage, high-capacity power electronic equipment, power quality issues have become increasingly prominent. Static var generators (SVG) have gained increasing popularity due to their advantages such as fast dynamic response and strong voltage surge suppression capabilities. SVG is used to compensate for reactive loads in new energy power plants, thereby avoiding power factor non-compliance and subsequent assessment by the power supply bureau. Different power plants may have different assessment points. If the assessment point is at a new energy power plant, traditional SVG power factor or load compensation modes can achieve reactive power compensation within the power plant, ensuring a power factor above 0.9. However, if the assessment point is at an upstream station of the new energy power plant, the reactive power at the assessment point includes the reactive power on the lines. Traditional SVG power factor and load compensation modes cannot compensate for line losses. To address this issue, this patent provides an algorithm that can achieve real-time compensation for line losses. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a method, system, equipment, and storage medium for compensating reactive power loss in new energy power plant lines, applicable to new energy power plants where the power factor assessment point is at the upstream station.

[0004] This invention is achieved through the following technical solution:

[0005] A method for compensating reactive power loss in new energy power plant lines includes the following steps:

[0006] S1, obtain the length, inductance, capacitance, reactive power loss, current, and voltage of the high-voltage transmission line under different active power conditions;

[0007] S2, perform offline fitting on the data obtained in S1 to obtain the real-time line loss reactive power of the transmission line;

[0008] S3 calculates real-time reactive power compensation using real-time line loss reactive power.

[0009] Preferably, in S1, the high-voltage transmission line is an overhead line.

[0010] Preferably, in S1, the method for calculating the reactive power loss of the high-voltage transmission line under different active power conditions is as follows: First, obtain the reactive power of the transmission line at a certain moment, and then calculate the reactive power loss of the line under different active power conditions.

[0011] Preferably, the reactive power of a high-voltage transmission line at a certain moment is calculated as follows: at the same moment, the difference between the real-time reactive power collected by the upper station and the real-time reactive power of the station is the reactive power of the high-voltage transmission line at that moment.

[0012] Preferably, in S2, a linear fitting method is used for offline fitting.

[0013] Preferably, in S2, the formula for calculating the real-time line loss reactive power of the transmission line obtained by fitting is: Q=k1×I-k2×U, where k1 and k2 are the coefficients obtained by fitting, I is the effective value of current, and U is the effective value of voltage.

[0014] Preferably, in S3, the reactive power loss of the transmission line calculated by the line reactive power loss formula is added to the reactive power set value of the SVG to obtain the reactive power that the SVG needs to provide; then, the real-time reactive power compensation of the transmission line is realized by using the constant reactive power control, load compensation mode or power factor mode of the SVG.

[0015] A reactive power loss compensation system for new energy power plant lines is provided. The system adopts a reactive power loss compensation method for new energy power plant lines and includes a data acquisition module, a fitting module, and a reactive power loss calculation module. The data acquisition module is used to acquire the length, inductance, capacitance, and reactive power loss, current, and voltage of the high-voltage transmission line under different active power conditions. The fitting module is used to perform offline fitting of the data acquired by the data acquisition module. The reactive power loss calculation module is used to perform real-time reactive power compensation calculation.

[0016] A terminal device includes a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement steps such as a method for compensating reactive power loss in a new energy power plant line.

[0017] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the reactive power loss compensation method for new energy power plant lines.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The reactive power loss compensation method for new energy power plant lines adopted in this invention utilizes data from the opposite station and the design documents of the new energy power plant to obtain the calculation method of reactive power loss of transmission lines, realize real-time compensation of reactive power loss of lines, and avoid the power factor being assessed due to line loss.

[0020] The reactive power loss of the transmission line is calculated in real time based on the current, voltage, transmission line length, capacitance and resistance. The reactive power loss that needs to be compensated for by the SVG is output in the transmission line, which solves the problem that the line loss of new energy power stations with the assessment point at the upper station cannot be controlled. The calculation is simple and the effect is obvious. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a method for compensating reactive power loss in a new energy power plant line according to the present invention.

[0022] Figure 2 Here is a flowchart for calculating line loss;

[0023] Figure 3 This is a flowchart for compensation of reactive power loss in power lines. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0025] This invention pertains to power quality products and is used in new energy power plants (photovoltaic or wind power) where the power factor assessment point is located at the upstream station. Because the power factor assessment point is at the upstream station, it assesses both line reactive power loss and the reactive power loss of the new energy power plant.

[0026] The SVG original load compensation mode can control the real-time reactive power output of the new energy power station to 0, but it cannot control the reactive power loss of the line in real time, resulting in an excessively low power factor, which leads to the new energy power station being subject to assessment.

[0027] A simplified block diagram of a certain new energy power station and its upstream power station can be found here. Figure 1 Point A is the assessment point for the power factor of the new energy power station by the superior station, and point B is the main outlet of the new energy power station. There is a 20km overhead transmission cable between A and B. The reactive power of the assessment point includes the reactive power loss of the 20km overhead transmission cable and the reactive power of the new energy power station.

[0028] A method for compensating reactive power loss in new energy power plant lines, referring to Figure 2 This includes the following steps:

[0029] S1, obtain the length, inductance, capacitance, reactive power loss, current, and voltage of the high-voltage transmission line under different active power conditions;

[0030] The length of the high-voltage transmission line is obtained from the design specifications of the new energy power plant.

[0031] Depending on their installation method, transmission lines include overhead lines and underground lines; different line types require different methods for calculating reactive power losses. When calculating the reactive power losses of high-voltage transmission lines, reactive power losses are directly proportional to current and inversely proportional to voltage.

[0032] The calculation method for reactive power loss of high-voltage transmission lines under different active power conditions is as follows: First, obtain the reactive power of the transmission line at a certain moment, and calculate it as follows: Then, obtain the reactive power loss of the line under different active power conditions through calculation.

[0033] The calculation method for reactive power loss of transmission lines under different active power conditions is as follows: First, obtain the reactive power of the transmission line at a certain moment. At the same moment, collect the difference between the real-time reactive power collected by the upper station and the real-time reactive power of the station, which is the reactive power of the high-voltage transmission line at this moment.

[0034] Among them, the high-voltage transmission lines are overhead lines.

[0035] S2, the data obtained in S1 is used to perform offline fitting using the linear fitting method to obtain the real-time line loss reactive power of the transmission line.

[0036] Conventional fitting methods include linear fitting, difference fitting algorithms, and grey model prediction. Linear fitting is simple and easy to implement in engineering applications. Difference fitting algorithms are suitable for predicting commodity sales volume and investment insurance returns, but not for industrial applications. Grey model prediction can generate relatively regular sequences using less feature data, but it is only used for short- to medium-term approximations and exponential growth predictions.

[0037] The real-time line loss reactive power of the transmission line is obtained by the following formula: Q = k1 × I - k2 × U, where k1 and k2 are the coefficients obtained by fitting, I is the effective value of current, and U is the effective value of voltage.

[0038] S3, refer to Figure 3 The calculation of real-time reactive power compensation using real-time line loss reactive power is as follows: The reactive power loss of the transmission line calculated by the line reactive power loss formula is added to the reactive power setpoint of the SVG to obtain the reactive power that the SVG needs to provide. Then, real-time reactive power compensation of the transmission line is achieved using the SVG's constant reactive power control, load compensation mode, or power factor mode. The constant reactive power control, load compensation mode, and power factor mode in this step are all traditional SVG control methods.

[0039] This invention provides reactive power loss compensation for new energy power plant lines. By using data from the opposite station and the design specifications of the new energy power plant, a method for calculating reactive power loss of transmission lines is obtained, enabling real-time compensation of reactive power loss and ensuring that the power factor at the assessment point is above 0.9 (as shown in Table 1).

[0040] Table 1 Example of reactive power loss compensation parameters for a power station line

[0041]

[0042] A reactive power loss compensation system for new energy power plant lines is provided. The system adopts a reactive power loss compensation method for new energy power plant lines and includes a data acquisition module, a fitting module, and a reactive power loss calculation module. The data acquisition module is used to acquire the length, inductance, capacitance, and reactive power loss, current, and voltage of the high-voltage transmission line under different active power conditions. The fitting module is used to perform offline fitting of the data acquired by the data acquisition module. The reactive power loss calculation module is used to perform real-time reactive power compensation calculation.

[0043] A terminal device includes a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement steps such as a method for compensating reactive power loss in a new energy power plant line.

[0044] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the reactive power loss compensation method for new energy power plant lines.

Claims

1. A method for compensating reactive power loss in a new energy power plant line, characterized in that, Includes the following steps: S1, obtain the length, inductance, capacitance, and reactive power loss, current, and voltage of the high-voltage transmission line under different active power conditions; Among them, the high-voltage transmission lines are overhead lines; The calculation method for reactive power loss of high-voltage transmission lines under different active power conditions is as follows: First, obtain the reactive power of the transmission line at a certain moment, and then calculate the reactive power loss of the line under different active power conditions. The method for calculating the reactive power of a high-voltage transmission line at a certain moment is as follows: at the same moment, the difference between the real-time reactive power collected by the upper station and the real-time reactive power of the station is the reactive power of the high-voltage transmission line at that moment. S2, perform offline fitting on the data obtained in S1 to obtain the real-time line loss reactive power of the transmission line; The formula for calculating the real-time line loss reactive power of the transmission line obtained by fitting is: Q=k1×I-k2×U, where k1 and k2 are the coefficients obtained by fitting, I is the effective value of current, and U is the effective value of voltage. S3, calculates real-time reactive power compensation using real-time line loss reactive power; The reactive power required by the SVG is obtained by adding the reactive power loss of the transmission line calculated by the reactive power loss formula to the reactive power set value of the SVG. Then, the reactive power compensation of the transmission line is realized in real time by using the constant reactive power control, load compensation mode or power factor mode of the SVG.

2. The method for compensating reactive power loss in new energy power plant lines according to claim 1, characterized in that, In S2, linear fitting is used for offline fitting.

3. A reactive power loss compensation system for new energy power plant lines, employing the reactive power loss compensation method for new energy power plant lines as described in any one of claims 1 to 2, characterized in that, It includes a data acquisition module, a fitting module, and a reactive power loss calculation module. The data acquisition module is used to acquire the length, inductance, capacitance, and reactive power loss, current, and voltage of the high-voltage transmission line under different active power conditions. The fitting module is used to perform offline fitting of the data from the data acquisition module. The reactive power loss calculation module is used to calculate reactive power compensation in real time.

4. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 2.

5. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 2.

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