HVDC Branch Load Flow Control Using Constant Resistance Shifts

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Solution Overview

Problem

High-voltage direct current transmission networks with load flow controllers become complex due to their static and dynamic behavior, making it difficult to control and understand the power flow effectively.

Innovation Solution

The method involves using load flow regulators to adjust the ohmic resistance of branches by a constant value, allowing for targeted control of power flow by acting as additional constant resistances or admittances, simplifying the network's behavior and description.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If load flow controllers are installed in branches to control power flow distribution, then power flow control capability is improved, but the static and dynamic behavior of the network becomes significantly more complex

Engineering Contradiction:
Improvepower flow control capabilityVSAvoidnetwork behavior complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the operational parameter of load flow controllers from variable resistance control to fixed resistance control. Each controller is assigned a constant resistance value that is predetermined based on network requirements. This parameter change simplifies the dynamic behavior while maintaining power flow distribution control capability, as the controllers no longer require complex real-time adjustments.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of using load flow controllers to actively regulate and adjust power flow in real-time (complex approach), the patent inverts the approach by using fixed resistance values that passively influence power flow distribution. The control is achieved through the structural configuration of fixed resistances rather than active regulation, thereby simplifying the system behavior.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If load flow controllers actively regulate power flow in real-time, then power distribution efficiency is improved, but the modeling and analysis of the network becomes difficult

Engineering Contradiction:
Improvepower distribution efficiencyVSAvoidmodeling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent transforms the time-varying resistance parameter of load flow controllers into fixed constant values. This parameter change allows the network to be modeled using standard linear circuit analysis methods, eliminating the need for complex nonlinear dynamic modeling while maintaining effective power distribution through the strategically chosen fixed resistance values.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple load flow controllers with independent control are deployed, then branch-specific power control is improved, but the overall network control becomes complicated

Engineering Contradiction:
Improvebranch-specific control capabilityVSAvoidnetwork control simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent segments the network control problem into independent branch-specific fixed resistance assignments. Each load flow controller is assigned a specific constant resistance value tailored to its branch's requirements, allowing independent optimization of each branch while the overall network behavior remains predictable and simple due to the fixed nature of these segmented control elements.

Inventive Principle:
Principle #1Segmentation

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 enables easier modeling and control of high-voltage direct current transmission networks, improving power distribution among branches and reducing energy losses, while minimizing the impact on dynamic behavior and allowing for overcurrent limitation.

Implementation Method 1

the load flow controller increases the ohmic resistance of the branch by a substantially constant value

Methodology Applied
Scientific EffectOhmic resistance: Electrical Resistance

Data Source

PatentEP4391267A1Method for influencing an electrical power flow
Publication Date: 2024.06.26 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP4391267A1 patent drawingFigure 1
  • EP4391267A1 patent drawingFigure 2
  • EP4391267A1 patent drawingFigure 3

AI summary

The invention relates to a method for influencing an electrical power flow in a high-voltage direct current transmission network (1), wherein the high-voltage direct current transmission network has a number of branches (21, 22, 23, 24, 25) and a number of nodes (11, 12, 13, 14), wherein some of the branches (21, 22) each have a load flow controller (301, 302). To reduce the electrical power transmitted via a branch (21) having a load flow controller (301), the load flow controller (301) increases the ohmic resistance of the branch (21) by a substantially constant value. To increase the electrical power transmitted via the branch (21) having the load flow controller (301), the load flow controller (301) decreases the ohmic resistance of the branch by a substantially constant value.