AC Equivalent Model for AC/DC Hybrid Power Flow Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing power flow analysis methods for AC/DC hybrid systems face challenges in accurately and efficiently calculating power flow distribution due to the complexity of coupling between DC and AC variables, with traditional methods either being inefficient or lacking convergence accuracy.
Innovation Solution
A power flow analysis device and method that constructs an AC equivalent model using DC transmission system structural and control parameters, such as trigger angles and commutation reactance, to transform the power flow analysis into a pure AC system problem, enabling quick and accurate calculation of power flow distribution in AC/DC hybrid systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the unified iteration method is used for power flow analysis in AC/DC hybrid systems, then convergence accuracy is improved, but calculation time increases and it becomes difficult to calculate complex networks
Solution Approach 1:
The patent segments the AC/DC hybrid power flow calculation into two distinct parts: an AC power flow calculation module and a DC power flow calculation module. The AC module handles AC system nodes and branches using traditional AC power flow methods, while the DC module handles DC system nodes and branches using DC power flow methods. This segmentation allows each module to be optimized independently, achieving fast calculation without sacrificing accuracy.
Solution Approach 2:
The patent introduces an equivalent model as an intermediary between the AC and DC systems. The converter station is modeled with equivalent impedance that connects the AC and DC power flow calculations. This intermediary allows the two different calculation systems to interact properly while maintaining their各自的 characteristics, enabling accurate power flow analysis without requiring complex unified iteration.
2Productivity
If the alternating iteration method is used for power flow analysis in AC/DC hybrid systems, then flexibility and calculation efficiency are improved, but convergence is not good due to not considering coupling between DC and AC variables
Solution Approach 1:
The equivalent model acts as a mediator that properly represents the coupling between AC and DC systems. The converter station equivalent impedance captures the interaction characteristics, allowing the alternating iteration method to converge accurately by providing the necessary coupling information without requiring complex coordinated iteration procedures.
Solution Approach 2:
The patent transforms the DC system parameters into an equivalent AC representation through the equivalent model. By converting DC variables into equivalent AC impedance parameters, the method enables the use of AC power flow techniques while maintaining the physical characteristics of the DC system, thus improving convergence without sacrificing efficiency.
3Device complexity
If traditional AC power flow methods are applied to AC/DC hybrid systems, then the complexity of the system increases, but the traditional methods can no longer meet the demand
Solution Approach 1:
The patent divides the AC/DC hybrid system into separate AC and DC calculation domains. Each domain uses its own optimized calculation methods, avoiding the need to develop entirely new methods for the hybrid system. This segmentation maintains the applicability of proven traditional methods while accommodating system complexity.
Solution Approach 2:
The patent creates a universal power flow analysis framework that can handle both AC and DC systems through a common interface. The equivalent model provides a unified representation that works with both AC and DC power flow algorithms, making the method broadly applicable to various AC/DC hybrid configurations without requiring system-specific modifications.
Data Source
AI summary
The present disclosure proposes a power flow analysis device and a power flow analysis method for an AC/DC hybrid system. Wherein, the device comprises: a memory being stored a computer program; and a processor performing the following steps when executing the computer program: obtaining an AC system voltage and a commutation reaction of the DC transmission system, a first trigger angle of the rectifier, and a second trigger angle of the inverter; constructing an AC equivalent model according to the AC system voltage, the commutation reaction, the first trigger angle, and the second trigger angle; and performing a power flow calculation according to the AC equivalent model to obtain a power flow analysis result of the AC/DC hybrid system. Therefore, the power flow analysis and calculation problem of the AC/DC hybrid system is transformed into the power flow analysis and calculation problem of the pure AC system, which overcomes the problem that the DC system variables are not easily decoupled in the power flow analysis and calculation, and takes into account the efficiency and accuracy of the power flow calculation.