Dynamic Feedback Gain Adjustment for MPPT Control

Solution Overview

Problem

Existing power conversion systems face challenges in efficiently tracking the maximum power point of renewable energy sources like solar cells, particularly in adapting to changing power supply characteristics and achieving optimal power output.

Innovation Solution

A power conversion apparatus comprising a power converter, a target command controller, a feedback controller, and a gain adjustor that adjusts feedback control gain based on supplied voltage, current, and target command to optimize power output, enabling improved maximum power point tracking (MPPT) control by dynamically adjusting feedback gain according to the power supply characteristic.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If feedback control is used to track maximum power point, then power output follows maximum suppliable power, but excessive responsiveness causes instability

Engineering Contradiction:

Improvepower outputVSAvoidcontrol stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The feedback gain is made dynamically adjustable based on the operating point relative to the maximum power point. When the operating point is far from MPP, a larger gain provides strong corrective action for quick response. When near MPP, the gain is reduced to prevent overshooting and oscillations, thus maintaining stability while achieving good tracking performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The feedback gain parameter is changed according to the deviation from maximum power point. The control system monitors the difference between current power output and maximum suppliable power, and adjusts the feedback gain accordingly - increasing gain when deviation is large, decreasing when deviation is small, optimizing both response speed and stability.

Inventive Principle:

Principle #35Parameter changes

2Speed

If feedback gain is increased to improve response speed, then MPPT tracking becomes faster, but control stability deteriorates

Engineering Contradiction:

Improveresponse speedVSAvoidcontrol stability

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The feedback gain is made dynamically adjustable based on the operating point relative to the maximum power point. When the operating point is far from MPP, a larger gain provides strong corrective action for quick response. When near MPP, the gain is reduced to prevent overshooting and oscillations, thus maintaining stability while achieving good tracking performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The feedback gain parameter is changed according to the deviation from maximum power point. The control system monitors the difference between current power output and maximum suppliable power, and adjusts the feedback gain accordingly - increasing gain when deviation is large, decreasing when deviation is small, optimizing both response speed and stability.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If feedback gain is decreased to improve stability, then control stability is maintained, but response speed becomes slower

Engineering Contradiction:

Improvecontrol stabilityVSAvoidresponse speed

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The feedback gain is made dynamically adjustable based on the operating point relative to the maximum power point. When the operating point is far from MPP, a larger gain provides strong corrective action for quick response. When near MPP, the gain is reduced to prevent overshooting and oscillations, thus maintaining stability while achieving good tracking performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The feedback gain parameter is changed according to the deviation from maximum power point. The control system monitors the difference between current power output and maximum suppliable power, and adjusts the feedback gain accordingly - increasing gain when deviation is large, decreasing when deviation is small, optimizing both response speed and stability.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10574058B2Power conversion apparatus, power generation system, controller, and method for performing control

Publication Date: 2020.02.25 YASKAWA DENKI KK

AI summary

A power conversion apparatus includes a power converter, a target command controller, a feedback controller, and a gain adjustor. The power converter is configured to convert first power supplied from a power generation source into second power. The target command controller is configured to increase or decrease a target command so as to cause the first power to follow maximum suppliable power of the power generation source. The feedback controller is configured to control the power converter by feedback control that is based on a deviation between the target command and at least one of a supplied voltage and a supplied current supplied from the power generation source to the power converter. The gain adjustor is configured to adjust a gain of the feedback control based on at least one of the supplied voltage, the supplied current, and the target command.