Inverter MPPT Control for Accurate Power Measurement

Solution Overview

Problem

Current solar power generation systems face inaccuracies in measuring electricity quantity due to insufficient measurement methods, particularly during transient states caused by maximum power point tracking (MPPT) control in inverters.

Innovation Solution

A solar power generation system is designed with an inverter, maximum power point tracking control, input power measurement section, output power measurement section, and conversion efficiency computation section, which avoids measuring power during transient states by using a measurement lock signal to ensure accurate computation of conversion efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If maximum power point tracking control is performed on the inverter, then power output from the solar battery is maximized, but measurement accuracy of electricity quantity deteriorates due to transient states

Engineering Contradiction:

Improvepower outputVSAvoidmeasurement accuracy

Core Design Contradiction:

PowerVSMeasurement precision

Solution Approach 1:

The control device predicts future DC voltage values and determines measurement timing in advance, performing preliminary action to schedule measurements during stable periods before transient states occur, thereby avoiding inaccurate measurements while maintaining MPPT power optimization

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from measured DC voltage and current values, combined with predicted future voltage values, to dynamically adjust measurement timing and determine when to perform accurate power measurements, creating a closed-loop control that adapts to changing operating conditions

Inventive Principle:

Principle #23Feedback

2Loss of information

If power measurement is performed continuously, then measurement data availability is improved, but measurement accuracy deteriorates due to inclusion of transient state data

Engineering Contradiction:

Improvemeasurement data availabilityVSAvoidmeasurement accuracy

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The control device predicts future DC voltage values and determines measurement timing in advance, performing preliminary action to schedule measurements during stable periods before transient states occur, thereby avoiding inaccurate measurements while maintaining MPPT power optimization

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from measured DC voltage and current values, combined with predicted future voltage values, to dynamically adjust measurement timing and determine when to perform accurate power measurements, creating a closed-loop control that adapts to changing operating conditions

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 approach improves the accuracy of electricity quantity measurement by preventing measurements during unstable transient states, thereby enhancing the overall efficiency computation of the inverter.

Implementation Method 1

DC power inputted from a solar battery

Methodology Applied

Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 2

an inverter configured to convert DC power inputted from a solar battery to AC power

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentUS10454417B2Solar power generation system

Publication Date: 2019.10.22 TMEIC CORP

AI summary

A solar power generation system includes an inverter configured to convert DC power inputted from a solar battery to AC power, a MPPT control section configured to perform maximum power point tracking control on the inverter, an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control, an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state, and a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section.