Microgrid Inverter Control Using Diesel Generator Voltage Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing microgrid systems face complexity and communication delays in real-time power adjustments, particularly when dealing with sudden changes in load power, which can lead to excess power being injected back into diesel generators, causing potential damage.

Innovation Solution

A microgrid inverter system comprising a controller, an inverter circuit, and a voltage sampling circuit, which modifies the output power of the inverter based on the frequency, amplitude, or effective value of the output voltage of the diesel generator, without the need for communication connections, thereby maintaining the stability of the microgrid system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a monitoring device is adopted to monitor multiple powers in real time and perform power scheduling, then the stability of the microgrid system can be maintained, but the process becomes complex and introduces communication delay

Engineering Contradiction:
Improvestability of microgrid systemVSAvoidcomplexity of monitoring and control process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the control function from a separate monitoring device and integrates it directly into the inverter. The inverter now directly monitors the diesel generator's output voltage and autonomously adjusts its own output power, eliminating the need for external communication and control systems while maintaining system stability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the monitoring and control functions into the inverter itself. The inverter combines voltage sampling capability, frequency detection, and power adjustment functions in a single integrated unit, simplifying the overall system architecture and eliminating communication delays between separate components.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If multiple powers are monitored in real time through communication connection, then power scheduling can be performed, but communication delay occurs and response time increases

Engineering Contradiction:
Improvepower scheduling capabilityVSAvoidcommunication delay
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The inverter performs self-monitoring and self-adjustment by directly detecting the diesel generator's output voltage frequency and autonomously modifying its output power accordingly. This self-service mechanism eliminates the need for external communication protocols and centralized control, achieving instantaneous response to power imbalances.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements a direct feedback loop where the inverter continuously samples the diesel generator's output voltage, detects frequency deviations, and immediately adjusts its output power in response. This closed-loop feedback system operates without communication delays, enabling real-time power balancing.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4554034A1Microgrid inverter, microgrid system, and method for controlling microgrid inverter
Publication Date: 2025.05.14 SUNGROW POWER SUPPLY CO LTD
  • EP4554034A1 patent drawingFigure 1~2
  • EP4554034A1 patent drawingFigure 3~4
  • EP4554034A1 patent drawingFigure 5~6

AI summary

A microgrid inverter is provided, including: a controller, an inverter circuit, and a voltage sampling circuit. A first terminal of the inverter circuit is connected to a renewable power source. An off-grid port of the inverter circuit is connected to a load. A grid-connected port of the inverter circuit is connected an output terminal of a diesel generator. The voltage sampling circuit samples an output voltage of the diesel generator. The controller is configured to modify an output power of the inverter circuit based on at least one of an amplitude, an effective value or a frequency of the output voltage of the diesel generator to control the output voltage to be within a predetermined range. The microgrid inverter may perform control only based on the data of output voltage collected from the diesel generator without establishing a communication connection, avoiding injecting excess power from the inverter circuit to the diesel generator. The microgrid inverter is simple and has no communication delay, thereby ensuring the stability of the microgrid system.