PV-Battery Control Power for Symmetrical Grid Balancing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Photovoltaic systems contribute to AC grid stabilization only to a limited extent due to their volatility and poor predictability, and existing methods for providing balancing power are inefficient and costly.

Innovation Solution

A method utilizing a photovoltaic generator and energy storage system to provide control power by adjusting total electrical power exchange based on current maximum PV power and energy storage state, allowing for symmetrical control power provision through optimal utilization of both systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional power plants (nuclear, coal, gas) are used to provide control power, then sufficient power can be generated, but high investment costs and long construction periods are required

Engineering Contradiction:
Improvecontrol powerVSAvoidinvestment cost and construction time
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent combines the energy generation function with the existing renewable energy plant infrastructure. The energy storage system is integrated into the plant's existing operations, allowing the same facility to both generate renewable energy and provide control power to the alternating voltage system, eliminating the need for separate conventional power plant construction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The energy storage system serves multiple functions: it stores energy from the renewable energy plant, provides control power to the alternating voltage system, and can respond to frequency deviations. This multi-functional approach replaces the need for dedicated conventional power plants while achieving the same control power objective.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If conventional power plants are constructed to provide control power, then power supply reliability is improved, but construction time is excessively long

Engineering Contradiction:
Improvecontrol power supply reliabilityVSAvoidconstruction period
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The energy storage system is pre-installed and charged during normal operations of the renewable energy plant before frequency deviations occur. When control power is needed, the stored energy is immediately available, eliminating the time delay associated with constructing conventional power plants while ensuring reliable power supply.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The renewable energy plant serves its own control power needs through its integrated energy storage system, making the system self-sufficient. This eliminates the need for external conventional power plants and their associated construction timelines, while maintaining reliable control power supply.

Inventive Principle:
Principle #25Self-service

3Speed

If energy storage systems are used to provide control power, then response speed to frequency deviations is improved, but the complexity of the energy storage system increases

Engineering Contradiction:
Improveresponse speed to frequency deviationVSAvoidenergy storage system complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The energy storage system is merged with the existing renewable energy plant infrastructure, sharing common control systems, monitoring equipment, and operational protocols. This integration approach enables fast response to frequency deviations while minimizing the additional complexity by utilizing existing system components.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If renewable energy plants without energy storage are used, then investment costs are reduced, but the ability to provide control power is insufficient

Engineering Contradiction:
Improveinvestment costVSAvoidcontrol power capability
Core Design Contradiction:
Ease of manufactureVSPower

Solution Approach 1:

The energy storage system is designed to serve multiple purposes: storing excess renewable energy, providing control power to the alternating voltage system, and enabling fast frequency response. This multi-functionality allows the system to provide adequate control power capability while avoiding the high costs of separate conventional power plants.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables cost-effective and efficient stabilization of the AC power grid by providing symmetrical control power, optimizing the use of photovoltaic generators and energy storage systems to react to power imbalances autonomously or upon request, ensuring maximum positive and negative control power availability.

Implementation Method 1

an energy storage system is coupled to the renewable energy plant

Methodology Applied
Scientific EffectElectrical energy storage: Electrical Accumulator

Data Source

PatentEP3903399B1Method for providing control power for an alternating voltage system by means of an energy-generating plant
Publication Date: 2026.04.22 SMA SOLAR TECH AG
  • EP3903399B1 patent drawingFigure 1
  • EP3903399B1 patent drawingFigure 2
  • EP3903399B1 patent drawingFigure 3

AI summary

The invention relates to an energy-generating plant (2) and to a method for providing control power for an alternating voltage system (1) by means of an energy-generating plant (2), the energy-generating plant (2) comprising a photovoltaic generator (4) and a stored energy source (5), the energy-generating plant (2) exchanging a total electrical power (P_Netz) with the alternating voltage system (1), the total power (P_Netz) exchanged being set as a function of a current maximum PV power (P_MPP), a predefinable basic PV power (P_PV_0) between zero and the maximum PV power (P_MPP), and a provided or required control power. The method comprises the following steps: - if no control power is required: feeding in a basic total power (P_Netz_0) comprising the basic PV power (P_PV_0); - if negative control power is required: reducing the PV power (P_PV) in comparison with the basic PV power (P_PV_0); - if positive control power is required: drawing a battery power (P_Batt) from the stored energy source (5) if the required positive control power is greater than the difference between the maximum PV power (P_MPP) and the basic PV power (P_PV_0).