Island-Mode Inverter Output Prioritization Under Overload
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Solution Overview
Problem
Inverters fail to supply essential loads during an overload, requiring central control units and communication connections to prioritize and deactivate loads, leading to complete shutdowns.
Innovation Solution
An inverter method that outputs phase-shifted alternating voltages to multiple outputs, each with assigned priority levels, deactivates the lowest priority output during overload, and iteratively adjusts to maintain supply to higher-priority loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the inverter operates in island mode to supply local energy supply networks during power outages, then essential loads can continue to operate, but the inverter must stop operating when electrical power required by loads exceeds available power (overload)
Solution Approach 1:
The inverter's output is segmented into multiple priority levels (first priority, second priority, etc.), allowing different loads to be supplied from different outputs. During overload conditions, the control device selectively deactivates lower-priority outputs while maintaining higher-priority outputs, ensuring continuous supply to essential loads without complete shutdown
Solution Approach 2:
Different outputs of the inverter are assigned different priority levels and characteristics. The control device applies different operational states to different outputs based on local conditions (priority assignment), allowing tailored power distribution where essential loads receive power first during overload situations
2Reliability
If individual loads are deactivated depending on prioritization to maintain operation during overload, then essential loads can continue to operate, but central control units and communication connections to loads are required
Solution Approach 1:
The invention extracts the prioritization control function from complex external control systems and embeds it directly in the inverter's control device. The inverter itself performs the intelligent decision-making about which loads to maintain or deactivate based on priority levels, eliminating the need for separate central control units and communication infrastructure
Solution Approach 2:
The inverter's control device autonomously monitors the electrical power balance and automatically deactivates appropriate outputs based on pre-assigned priority levels without requiring external control signals or communication with loads. The system serves itself by making real-time decisions based on its own operational state
Data Source
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AI summary
The invention relates to a method for operating an inverter (1) in island mode, wherein the inverter (1) has at least two outputs (8a-c) for connecting electrical outer conductors (L1, L2, L3), and the method comprises the following steps: i) outputting alternating voltages (U1, U2, U3), in particular those which are phase-shifted with respect to one another, at outputs (8a-c) which have been activated, wherein each of the at least two outputs (8a-c) is assigned a priority level (A, B, C); ii) checking the inverter (1) for an electrical overload; iii) deactivating that output (8a-c) with the lowest priority level (A, B, C) at which an alternating voltage (U1, U2, U3) is output, by terminating the output of the alternating voltage (U1, U2, U3) at this output (8a-c) if an overload of the inverter (1) has been detected.Furthermore, the invention relates to a method for supplying energy to a local energy supply network (2) and to an inverter (1).