Energy Storage Insulation Impedance Detection for Fault Localization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power generation and power supply systems face challenges in accurately detecting and locating short-circuit-to-ground faults due to poor precision and adaptability of ground insulation detection apparatuses, especially in energy storage systems with multiple inverters or converters, which can lead to safety risks and inefficiencies.
Innovation Solution
An energy storage system equipped with a first and second insulation impedance detection apparatus, along with a controller, allows for real-time detection of insulation impedance by connecting energy storage units and converters to a power grid, enabling precise location of short-circuit-to-ground faults through adaptive threshold adjustments and selective disconnection of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a ground insulation detection apparatus is installed to detect the ground impedance of the entire power supply system, then real-time detection may be performed when the power supply system normally runs, but ground impedance detection precision is poor and specific short-circuit-to-ground faults cannot be located
Solution Approach 1:
The patent divides the power supply system into multiple detectable units by connecting second detection apparatuses to individual direct current side lines or energy storage units. This segmentation allows precise localization of faults while maintaining real-time monitoring through the first detection apparatus connected to the alternating current side, resolving the contradiction between real-time detection capability and detection precision.
2Reliability
If a fixed protection threshold is used for the ground insulation detection apparatus, then short-circuit-to-ground fault determining can be triggered, but adaptability to power supply systems of different scales is poor
Solution Approach 1:
The patent implements dynamic threshold adjustment by calculating reference impedance values based on the actual configuration of energy storage units and converters in the system. The controller adapts the protection threshold dynamically to match system scale and topology, enabling reliable fault detection across different system configurations while maintaining adaptability to varying scales.
3Measurement precision
If multiple second insulation impedance detection apparatuses are deployed to locate specific faults, then fault location precision improves, but system complexity and cost increase
Solution Approach 1:
The patent strategically places second detection apparatuses at critical points such as direct current side lines or individual energy storage units, segmenting the monitoring function to achieve precise fault localization. This selective segmentation balances detection precision requirements with system complexity, avoiding unnecessary apparatus deployment while maintaining high fault location accuracy.
Solution Approach 2:
The controller serves as an intermediary that coordinates between the first detection apparatus on the alternating current side and multiple second detection apparatuses on the direct current side. It integrates detection data from multiple sources, processes the information centrally, and determines fault locations, thereby simplifying the overall system architecture while maintaining high detection precision.
Data Source
AI summary
An energy storage system and an insulation impedance detection method for an energy storage system. The energy storage system includes a plurality of energy storage converters, a plurality of energy storage units, one first insulation impedance detection apparatus, a plurality of second insulation impedance detection apparatuses, and a controller. The energy storage units are connected to direct current ends of the energy storage converters, and are correspondingly connected to the second insulation impedance detection apparatuses, and a parallel connection point of alternating current ends of the plurality of energy storage converters is connected to the first insulation impedance detection apparatus. When a first insulation impedance is abnormal, the controller controls the plurality of second insulation impedance detection apparatuses to detect corresponding second insulation impedances, and sends an alarm signal if there is an abnormal second insulation impedance.