AC Grid Simulation Circuit Using Reversible AC-DC Converter

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Photovoltaic panels experience irreversible performance degradation when exposed to open circuit light, and existing simulation circuits require an alternating current source connected to an electrical supply network, making them costly and complex to implement.

Innovation Solution

A circuit that simulates an alternating electrical network by combining resistors with power electronic components, eliminating the need for an alternating current source, and includes a reversible AC-DC converter to emulate an AC network, allowing the photovoltaic inverter to operate as if connected to an AC network without actual network availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If fixed load resistors are positioned on the direct current circuit of photovoltaic panels, then the cost is reduced, but the operating point cannot be controlled as a function of solar radiation

Engineering Contradiction:
ImprovecostVSAvoidoperating point control
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent introduces an intermediary control system that measures solar radiation and automatically adjusts the resistor bank configuration to maintain optimal operating points. This mediator between the solar panels and resistors enables both cost-effectiveness and adaptability to varying solar conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If an alternating current source is used in the simulation circuit, then the AC network can be simulated, but the device complexity increases and requires connection to an electrical supply network

Engineering Contradiction:
ImproveAC network simulation capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of AC network simulation from the complex AC source requirement. By using a resistor bank with switched configurations on the DC side, it reproduces the electrical characteristics of an AC network without needing an actual AC source, thereby eliminating the need for external electrical supply network connection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified copy of the AC network's electrical behavior using resistive elements. Instead of replicating the entire AC network infrastructure, it copies the essential load characteristics through resistor configurations that simulate grid impedance and loading conditions.

Inventive Principle:
Principle #26Copying

3Reliability

If an alternating current source is used in the simulation circuit, then the AC network simulation is possible, but the cost and implementation complexity increase

Engineering Contradiction:
ImproveAC network simulation capabilityVSAvoidimplementation cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, complex AC source equipment with inexpensive resistor elements and switching components. The resistor bank uses simple, readily available components that can be easily manufactured and deployed, eliminating the need for costly programmable AC sources while maintaining simulation functionality.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

The solution significantly reduces system costs by eliminating the need for an AC source and allows the photovoltaic panel or power plant to operate effectively during installation and connection to an electricity evacuation network without an AC network, maintaining optimal operating conditions and reducing performance degradation.

Implementation Method 1

at least a reversible AC-DC converter whose second alternating current side is connected to the alternating current port and whose direct current side is connected to a direct current energy dissipation sub-circuit

Methodology Applied
Scientific EffectAC-DC conversion:

Implementation Method 2

an electric battery capable of being charged with direct current and of being discharged in direct current

Methodology Applied
Scientific EffectBattery energy storage: Battery (electricity)

Implementation Method 3

a bank of first resistors capable of being selectively connected to the alternating current port

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3017480B1Simulation circuit of an alternating electric grid and method for controlling same
Publication Date: 2018.08.08 ELECTRICITE DE FRANCE
  • EP3017480B1 patent drawingFigure 1
  • EP3017480B1 patent drawingFigure 2
  • EP3017480B1 patent drawingFigure 3

AI summary

The invention relates to a simulation circuit (1) of an alternating electric grid, the circuit having at least one alternating port (2), a bank (3) of first resistances (31, 32, 33, 3n) that can be selectively connected to the alternating port (2) by connecting means (4, 41, 42, 43, ..., 4n). According to the invention, the circuit (1) comprises a reversible AC-DC converter (5) comprising an alternating side (51) connected to the alternating port (2) and a direct side (52) connected to a sub-circuit (6) for dissipating energy into direct current connected to an electric battery (7) able to be charged with direct current and discharged with direct current.