System Harmonic Impedance Estimation Method and System Based on Minimum Impedance and Voltage Norm
A harmonic impedance and norm technology, applied in the field of system harmonic impedance estimation, can solve problems such as grid background harmonic fluctuations, unsuitable for new grid scenarios, etc., achieve low error, good estimation accuracy, and prevent overfitting Effect
Active Publication Date: 2021-11-09
STATE GRID SICHUAN ELECTRIC POWER CORP ELECTRIC POWER RES INST
View PDF8 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
However, in the current power electronic power system, the number of harmonic sources increases, the interaction of each harmonic source and the change of the network operation mode, the background harmonics in the power grid fluctuate; at the same time, the user side usually installs filters and Reactive power compensation capacitor device, in some frequency components, the harmonic impedance of the user side is not much larger than the harmonic impedance of the system side
Most of the existing methods are based on the assumption that the background harmonics are stable and the user-side harmonic impedance is much larger than the system-side harmonic impedance, which will not be suitable for the new power grid scenario of existing power electronics.
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0094] In order to understand the above-mentioned purpose, features and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, under the condition of not conflicting with each other, the embodiments of the present application and the features in the embodiments can be combined with each other.
[0095] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from the scope of this description. Therefore, the protection scope of the present invention is not limited by the following disclosure. limitations of specific examples.
[0096] Those skilled in the art should understand that in the disclosure of the present invention, the terms "vertical", "transverse", "upper", "lower", "front",...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a system harmonic impedance estimation method and system based on the minimum impedance and voltage norm. The method includes: step (A): sampling the harmonic voltage and current at the PCC in the power grid within a preset period of time to obtain The measurement data of harmonic voltage and current in the preset period, and establish the PCC system side circuit equation, PCC is the common coupling point; step (B): for the harmonic voltage and current measurement data in step (A), according to The equivalent circuit equation at the PCC, the system-side harmonic impedance and system-side harmonic voltage norm minimization criteria, establish the optimization equation of the sampling sub-interval; step (C): based on the gradient descent method, the established in step (B) The optimization equation is iteratively solved to obtain the solution result, and the solution result is substituted into the PCC system side circuit equation to calculate the system side harmonic impedance; this method meets the actual engineering needs, and has good estimation accuracy and low error.
Description
technical field [0001] The invention relates to the field of harmonic emission level and harmonic research in power quality in power grids, in particular to a method and system for estimating system harmonic impedance based on the minimum impedance and voltage norm. Background technique [0002] With the continuous development and application of power electronics technology in the power grid, the access of a large number of nonlinear loads, such as inverters and electric vehicle charging piles, has caused extremely serious harmonic pollution in the power grid. How to quantitatively divide the harmonic responsibilities of each harmonic source in the access system is the premise of realizing intelligent management and control of power quality, and the accurate calculation of harmonic impedance is the basis and key of responsibility division. [0003] Usually based on the equivalent circuit of the harmonic source, a common connection point (PCC) is selected, and the system side...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01R27/16
CPCG01R27/16
Inventor 徐琳滕予非魏巍刘畅杨华唐伟
Owner STATE GRID SICHUAN ELECTRIC POWER CORP ELECTRIC POWER RES INST