Photovoltaic Inverter Group Control for Low-Voltage Overlimit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-proportion photovoltaic access in low-voltage distribution networks leads to voltage overlimit issues, which existing control strategies struggle to address effectively, particularly in terms of robustness during load and photovoltaic fluctuations.
Innovation Solution
A method for group coordinated voltage control of photovoltaic inverters, where inverters are divided into voltage control groups, using reactive and active power management through consistency algorithms to regulate voltage, with reactive power control prioritized to avoid unnecessary active power reduction, and a communication-based strategy to engage additional groups when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If massive photovoltaic access is implemented in low-voltage distribution networks, then clean energy utilization and system flexibility are improved, but voltage overlimit problems occur that restrict further photovoltaic integration
Solution Approach 1:
The patent divides photovoltaic inverters into multiple voltage control groups based on their locations and voltage regulation capacities. Each group is managed independently with dedicated control strategies, allowing the system to handle massive photovoltaic access while maintaining voltage stability through distributed control rather than centralized management.
Solution Approach 2:
The patent dynamically adjusts control parameters including reactive power output, voltage setpoints, and group assignments based on real-time photovoltaic generation and load conditions. This enables the system to adapt to varying photovoltaic access levels while preventing voltage overlimit through continuous parameter optimization.
2Reliability
If decentralized DG is divided into several groups for regional voltage management, then voltage regulation capability is improved, but control complexity increases with multiple consistency variables and change rates
Solution Approach 1:
The patent segments the distribution network into multiple voltage control groups, where each group is managed by a simplified local controller. This segmentation reduces control complexity by distributing decision-making authority while maintaining effective voltage regulation through coordinated group management.
Solution Approach 2:
Each voltage control group performs self-regulation using local measurements and simplified control logic, reducing the need for complex centralized coordination. The groups autonomously adjust their reactive power output based on local voltage conditions, minimizing overall control system complexity while maintaining regulation capability.
3Reliability
If reactive power output is used to adjust control node voltage for optimal DG scheduling, then voltage profile control is improved, but power factor decreases leading to more active power reduction
Solution Approach 1:
The patent optimizes the relationship between reactive power output and power factor by dynamically adjusting control parameters. Instead of fixed reactive power compensation, the system modifies power factor settings based on voltage conditions and photovoltaic generation levels, achieving voltage control while minimizing active power reduction and maintaining higher productivity.
4Measurement precision
If clustered partitioning is performed with reactive matching degree and node coupling degree as indexes, then voltage sensitivity analysis is improved, but method reliability decreases with small sample sizes
Solution Approach 1:
The patent performs preliminary clustering of photovoltaic inverters into voltage control groups based on location and voltage regulation capacity before operation. This pre-established clustering structure provides a reliable foundation for voltage control that does not depend on small-sample statistical analysis, ensuring method reliability while maintaining measurement precision through the predefined group structure.
Data Source
AI summary
The present invention discloses a method for group coordinated voltage control of photovoltaic inverters in a low-voltage distribution network, which relates to the technical field of voltage control of a low-voltage distribution network. The photovoltaic inverters are subjected to group coordinated control, and the sequence of groups for participating in voltage control is adjusted according to the VSF of each group. The photovoltaic inverters in the groups perform voltage control by consistency variables, and coordinated control strategies are used between the groups for control. A group with higher voltage sensitivity is preferably used to participate in voltage control, and then a voltage control instruction is sent to other groups, so as to effectively inhibit voltage overlimit, avoid unnecessary active reduction, and achieve strong robustness during load and photovoltaic fluctuation.