Distributed Power Supply Access Capacity Determination
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Solution Overview
Problem
The integration of distributed renewable energy sources into distribution networks leads to voltage and current violations, particularly overvoltage issues at the point of common coupling, which can disconnect distributed generators and reduce the power grid's hosting capacity, posing challenges for safe and efficient operation.
Innovation Solution
A method and device that determine the capability of a feeder in accepting distributed power supply by calculating feeder loss, voltage variations, and maximum active power value, considering three-phase mutual inductance and time-varying load characteristics, to improve grid planning and operation control, ensuring safe and efficient integration of distributed generators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If distributed generation capacity is increased to meet renewable energy requirements, then clean energy production increases, but voltage violations and overvoltage issues occur at the point of common coupling
Solution Approach 1:
The patent calculates the maximum active power value of distributed generation in advance by considering three-phase mutual inductance and feeder loss, establishing a pre-determined hosting capacity limit before actual DG connection. This preliminary calculation prevents overvoltage issues by ensuring DG capacity does not exceed the feeder's acceptable threshold.
Solution Approach 2:
The patent establishes a feedback mechanism where voltage variations are continuously monitored and used to adjust the maximum active power determination. The voltage constraint feedback loop ensures that when voltage deviations occur, the DG capacity is adjusted accordingly to maintain voltage stability within acceptable ranges.
2Productivity
If conventional single-point fixed value method is used for DG capacity calculation, then calculation simplicity is maintained, but time-varying load characteristics are not considered leading to inaccurate results
Solution Approach 1:
The patent transitions from static single-point calculation to dynamic multi-point calculation along the feeder. By calculating maximum active power values at multiple nodes considering time-varying load characteristics and three-phase mutual inductance, the method captures the dynamic nature of DG hosting capacity throughout the feeder while maintaining computational efficiency through analytical solutions.
3Measurement precision
If three-phase mutual inductance and feeder loss are comprehensively considered, then calculation accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent extracts and separately calculates the impact of three-phase mutual inductance and feeder loss from the complex power flow equations. By isolating these factors and developing dedicated calculation formulas for maximum active power determination, the method maintains high accuracy while avoiding the need for complex iterative power flow solutions.
Data Source
AI summary
A method and an apparatus for determining the distributed power supply capacity to be accessed by a feed line of a power distribution network, and a storage medium, the method comprising: determining feed line loss on the basis of load information of power distribution network feed line access nodes and circuit parameters; on the basis of the feed line loss, determining three-phase voltage change values of the feed line circuit; using a single phase having the greatest voltage change amongst the voltage change values, determining a maximum active power for distributed power supply access under voltage constraints; comparing the current of the feed line corresponding to the maximum active power with a circuit current limit, and determining the distributed power supply capacity to be accessed by the feed line; the apparatus comprises a feed line information collection unit, a voltage drop unit, a quantitative calculation unit, and a results analysis unit. The present method can be used for dispatching operation control of a distributed power supply in a power grid, and can ensure safe access to the distributed power supply and safe operation of the power grid, improving the access capacity of the power distribution network to the distributed power supply.