Storage Battery Discharge Control for Solar Energy Systems

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Solution Overview

Problem

Conventional energy storage systems do not effectively utilize solar energy during non-emergency situations, leading to power shortages at night when solar power generation is insufficient to meet load device demands, and they fail to provide continuous power supply during emergencies.

Innovation Solution

An energy storage system that manages the discharge of a storage battery based on a reference charge level, allowing discharge during the day when solar power exceeds consumption and prohibiting it when it does not, while ensuring the battery is charged during the day to provide power at night, and allowing discharge during emergencies to maintain a backup level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the storage battery discharges during the day when solar power is insufficient, then the power supply to load devices is maintained, but the storage battery cannot provide sufficient power at night

Engineering Contradiction:
Improvepower supply reliabilityVSAvoidbattery discharge duration
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The system dynamically adjusts the battery discharge behavior based on the time of day. During daytime, discharge is permitted when solar power is insufficient, while nighttime discharge is restricted to preserve battery capacity. This dynamic control strategy optimizes power supply reliability during critical periods while maintaining sufficient battery duration for nighttime operations.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the storage battery is fully charged with solar power during the day, then solar energy utilization is maximized, but the system cannot ensure sufficient backup power for emergencies

Engineering Contradiction:
Improvesolar energy utilizationVSAvoidemergency backup capability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system applies different charge level requirements for different operational scenarios. A first reference charge level (higher) is maintained during daytime to ensure sufficient power for nighttime operations, while a second reference charge level (lower) is acceptable during emergencies. This localized quality adjustment allows maximum solar energy utilization while preserving emergency backup capability.

Inventive Principle:
Principle #3Local quality

3Duration of action of moving object

If the storage battery discharges below the reference charge level, then nighttime power supply is improved, but the battery may not have sufficient capacity for the next day's operations

Engineering Contradiction:
Improvenighttime power supply durationVSAvoidnext day operation reliability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The control device continuously monitors the storage battery's charge level and provides feedback control. When the charge level reaches the first reference charge level during daytime, the system adjusts discharge behavior to prevent the battery from dropping below acceptable thresholds. This feedback mechanism ensures nighttime power supply duration is extended while maintaining sufficient capacity for next day operations.

Inventive Principle:
Principle #23Feedback

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 system optimizes the use of solar energy during the day, ensures power supply at night by allowing battery capacity to drop, and provides continuous power during emergencies by maintaining the battery's charge level above a backup threshold.

Implementation Method 1

the storage battery is charged with electric power from the solar cell

Methodology Applied
Scientific EffectSolar energy conversion: Photovoltaic Effect

Data Source

PatentEP2475060B1Energy storage system
Publication Date: 2018.05.23 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2475060B1 patent drawingFigure 1
  • EP2475060B1 patent drawingFigure 2~3
  • EP2475060B1 patent drawingFigure 4

AI summary

In an energy storage system, power from at least one of a solar cell, a commercial AC power source, and a storage battery is supplied to load devices. In the daytime, under the condition that an amount of power generated by the solar cell is less than an amount of power consumed by the load device, the discharge from the storage battery to the load device is permitted or prohibited if the charge level of the storage battery is higher or is not higher than the reference charge level. The discharge from the storage battery which makes the charge level of the storage battery lower than the reference level is permitted at night.