Variable Frequency Bus Synchronization Controller for Marine Power Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Off-grid power generation systems, such as those in marine vessels, face inefficiencies and increased operational costs due to the need for frequent frequency and voltage conversions, which result in 2-8% overall efficiency loss and complex control systems that impact cycle time and maintenance.
Innovation Solution
A variable frequency bus system with a synchronization controller that determines an optimal bus frequency and available power range, allowing for asymmetric loading of variable frequency generator sets to directly supply power to variable frequency loads without intermediate frequency conversion stages, thereby eliminating efficiency losses and simplifying control systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency conversion stages are used to synchronize genset output with the common bus, then frequency and voltage compatibility is improved, but overall efficiency deteriorates due to 2-8% energy loss
Solution Approach 1:
The patent extracts and eliminates the frequency conversion stage from the system. By directly connecting variable frequency gensets to variable frequency loads through a common bus without intermediate conversion equipment, the system removes the source of 2-8% efficiency loss while maintaining compatibility through direct variable-to-variable frequency coupling.
Solution Approach 2:
Instead of converting variable frequency genset output to constant frequency (traditional approach), the patent inverts the approach by allowing the common bus to operate at variable frequency and directly connecting variable frequency loads to it. This reversal eliminates the need for conversion stages and associated energy losses.
2Reliability
If frequency conversion stages are implemented, then compatibility with the common bus is improved, but system complexity increases due to additional control systems and protective measures
Solution Approach 1:
The patent removes frequency conversion stages and their associated complex control systems and protective measures from the architecture. By enabling direct connection between variable frequency gensets and variable frequency loads, the system eliminates the need for intermediate conversion equipment and its complicated control infrastructure.
Solution Approach 2:
The patent inverts the traditional constant frequency approach by implementing a variable frequency common bus that directly accepts variable frequency genset output. This inversion simplifies the system by eliminating conversion stages and their complex control systems, allowing direct variable-to-variable frequency coupling.
3Reliability
If complex control systems are used for frequency conversion, then frequency and voltage maintenance is improved, but operational costs increase
Solution Approach 1:
The patent extracts and eliminates frequency conversion stages from the system architecture. By directly connecting variable frequency gensets to variable frequency loads through a common bus, the system removes the source of 2-8% efficiency loss and eliminates complex control systems, thereby reducing operational costs while maintaining compatibility.
Solution Approach 2:
Instead of converting variable frequency to constant frequency through expensive conversion stages, the patent inverts the approach by operating the common bus at variable frequency and directly connecting variable frequency loads. This reversal eliminates conversion equipment and associated operational costs while maintaining system compatibility.
4Reliability
If frequency conversion stages are used, then compatibility with the common bus is improved, but cycle time deteriorates due to impact on variable frequency equipment operation
Solution Approach 1:
The patent removes frequency conversion stages from the system, eliminating the time delays and operational impacts associated with conversion processes. By enabling direct connection between variable frequency gensets and variable frequency loads, the system eliminates intermediate conversion steps that adversely affect cycle time.
Solution Approach 2:
The patent inverts the traditional approach by allowing the common bus to operate at variable frequency rather than forcing conversion to constant frequency. This inversion eliminates conversion stages and their associated cycle time impacts, allowing variable frequency equipment to operate more efficiently.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances fuel efficiency, reduces system complexity and costs, and improves power delivery by optimizing load sharing among generator sets based on their operating ranges and fuel efficiency, minimizing impedance and emissions.
Implementation Method 1
The frequency and voltage of the gensets must be synchronized with the electrical load on the common bus
Implementation Method 2
The motive force, in turn, is used to rotate a rotor relative to a stator of the generator so that a rotating magnetic field induces an electrical current in the field windings of the stator
Data Source
AI summary
A system and method for synchronizing a frequency of plurality of variable frequency generators with a variable frequency load over a variable frequency bus independent of a frequency conversion stage. A synchronization controller is configured to determine an optimal bus frequency of the variable frequency bus based on at least one power demand requirement of the variable frequency load operatively connected to the variable frequency bus. With the optimal frequency, an available power range supplied by the plurality of variable frequency gensets at the optimal bus frequency can be determined. The synchronization controller then asymmetrically loads the variable frequency load to the plurality variable frequency gensets at the optimal bus frequency based on the operating range of each variable frequency genset and recursively updates the optimal bus frequency based on operational statistics of the asymmetrically loaded variable frequency gensets.