Generator Control Method for Microgrid Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling virtual generators in microgrids face instability issues, particularly during short-circuits and low currents, and are complex to configure, depending on the micro-network architecture, with virtual impedances affecting efficiency.
Innovation Solution
A control method for a generator with an inverter using instantaneous duty cycles, comprising an observation loop to estimate network current, an integration loop to evaluate deviations, and a correction loop to adjust duty cycles, ensuring stability and independence from network configuration, allowing the inverter to deliver balanced power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If virtual impedances are implemented in the control law to guarantee stability, then the stability of the virtual generator is improved, but the device complexity increases and the efficiency decreases due to current extraction requirements
Solution Approach 1:
The patent extracts and eliminates the virtual impedance component from the control law, removing the source of complexity while maintaining stability through alternative control mechanisms that directly regulate current and voltage without requiring impedance modeling
Solution Approach 2:
The patent changes the control parameters from impedance-based control to direct current and voltage regulation, transforming the control law into a simpler form that achieves stability through parameter optimization rather than complex impedance configuration
2Reliability
If virtual impedances are implemented in the control law to guarantee stability, then the stability of the virtual generator is improved, but the efficiency decreases due to current extraction
Solution Approach 1:
The patent removes the virtual impedance extraction mechanism from the control system, eliminating the associated energy losses while preserving stability through direct control of current and voltage parameters that do not require additional current sampling
3Reliability
If virtual impedances are configured to ensure stability, then the reliability is improved, but the ease of operation decreases due to architecture dependency
Solution Approach 1:
The patent creates a universal control law that is independent of specific micro-network architectures, making the stability solution applicable to various configurations without requiring architecture-specific impedance tuning or complex setup procedures
4Reliability
If observation and correction loops are added to estimate network current and adjust duty cycles, then the stability is improved, but the device complexity increases
Solution Approach 1:
The patent implements a self-regulating control system where the observation and correction loops automatically adjust duty cycles based on real-time network conditions without requiring external intervention or complex configuration, achieving stability through self-service operation
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a method of controlling a generator (1) comprising an inverter (4) provided with electronic switches which, controlled on the basis of instantaneous duty cycles αabc, allow said inverter (4) to deliver to an electrical distribution network an electrical power Pabc of alternating voltage, Vabc, and of alternating current Iabc, said voltage Vabc and current Iabc having a frequency fabc, the inverter (4) being controlled by a control law which includes: a) an integration loop (102) intended to evaluate a difference ε between the current Iabc and a network current Ir, actually required by the electrical distribution network; b) a correction loop (103) which, when the deviation ε is greater than a reference deviation ε*, controls the adjustment by the inverter (4) of the source current of the instantaneous duty cycles αabc so as to reduce the deviation ε to a value less than the reference deviation ε*.