Variable-Speed Engine Generator Control for Fuel Efficiency

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Solution Overview

Problem

Existing internal combustion engine-generator systems face challenges in optimizing fuel consumption and load switching capacity, especially during dynamic and highly variable-speed operations, leading to inefficiencies and insufficient power reserve.

Innovation Solution

A method and device for controlling and regulating internal combustion engine-generator systems using a computer model-based approach to determine the current operating state and load switching capacity, allowing for optimized operation by adjusting speed and load distribution among multiple units based on load requirements, thereby maintaining a sufficient power reserve and efficient fuel consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the diesel engine is operated at a constant speed with a power reserve maintained by operating according to a characteristic curve at a safe distance from the power limit, then the power reserve is sufficient for variable load requirements, but the fuel efficiency deteriorates

Engineering Contradiction:
Improvepower reserveVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by transitioning from constant-speed operation to variable-speed operation. The control system dynamically adjusts the engine speed based on actual load requirements, allowing the engine to operate at optimal points rather than maintaining a fixed speed with excessive power reserve. This resolves the contradiction by making the power reserve adaptive to actual needs while maintaining fuel efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters by allowing speed variation within a defined range rather than maintaining constant speed. The control system modifies speed, injection quantity, and injection timing parameters dynamically based on load conditions, enabling the engine to operate efficiently across different load levels while maintaining sufficient power reserve when needed.

Inventive Principle:
Principle #35Parameter changes

2Power

If the diesel engine is operated at higher speeds to deliver more power in variable-speed operation, then the power output increases, but the fuel efficiency deteriorates

Engineering Contradiction:
Improvepower outputVSAvoidfuel consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts engine speed based on actual power demands rather than operating at consistently high speeds. The control algorithm determines optimal operating points that balance power output requirements with fuel efficiency, allowing the engine to operate at lower speeds when full power is not needed while maintaining the capability to increase power when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs parameter changes by optimizing injection quantity and injection timing alongside speed control. The control system adjusts these parameters to match the actual power demand, preventing excessive fuel consumption at high speeds while maintaining the ability to deliver required power output when necessary.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the target injection quantity is limited by a speed limiting curve in stationary operating state, then the adjustment range is restricted, but upon detection of dynamic operating state, switching to a second speed limiting curve enables broader adjustment

Engineering Contradiction:
Improveadjustment rangeVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by implementing dynamic switching between different control characteristics based on operating state detection. The control system transitions from stationary to dynamic operating mode detection, adjusting the speed limiting curve accordingly to provide appropriate adjustment range for each operating condition while managing control complexity through state-based decision logic.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2710246B1Method and apparatus for performing open-loop and closed-loop control of an internal combustion engine generator system
Publication Date: 2021.01.06 ROLLS ROYCE SOLUTIONS GMBH
  • EP2710246B1 patent drawingFigure 1
  • EP2710246B1 patent drawingFigure 2
  • EP2710246B1 patent drawingFigure 3

AI summary

The invention relates to a method for performing open-loop and closed-loop control of an internal combustion engine generator system (1000) having a number of internal combustion engine generator units (400) which can be connected to a distributor network and generate electrical power, and loads (200) which consume electrical power, wherein a unit (400) has an internal combustion engine (401, 402, 404 - 408) with a variable rotational speed and a generator (421 - 428), characterized by the steps: determination of a current operating state Z* of the internal combustion engine (401, 402, 404 - 408) of the at least one internal combustion engine generator unit (400); derivation of an operating state range ZB* which describes a load application capability Ladm as a function of the current operating state Z*, for the internal combustion engine of the at least one internal combustion engine generator unit (400), wherein the determination of the current operating state Z* and the derivation of the operating state range ZB* take place on the basis of a computational model (504) for the internal combustion engine (401, 402, 404 - 408); provision of a load request scope which describes possible load requests of the number of loads (200).