Module-Level Inverter Transistor Merging for Rapid Shutdown

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Solution Overview

Problem

The existing inverter architectures for solar power systems require a large number of transistors to meet rapid shutdown requirements, leading to increased complexity and cost, especially with the need for multiple PV arrays and inverters.

Innovation Solution

A distributed inverter architecture that reduces the number of transistors by distributing them across multiple inverters, using MOSFET switches connected to the positive or negative terminals of photovoltaic modules, allowing for reduced component count and combined quick-disconnect functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a MOSFET switch is located within 1 foot of the photovoltaic panel to meet NEC 2017 rapid shutdown requirements, then safety compliance is improved, but the number of transistors and system complexity increases

Engineering Contradiction:

Improverapid shutdown complianceVSAvoidnumber of transistors

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the rapid shutdown MOSFET switch with the power inverter transistors into a single integrated component. The inverter transistors perform dual functions: power conversion and rapid shutdown, eliminating the need for separate shutdown switches and reducing total transistor count

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The inverter transistors are designed to serve multiple purposes: they function as power switching elements for DC-to-AC conversion and simultaneously serve as rapid shutdown switches for safety compliance. This multi-functionality reduces overall system complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If the number of transistors is reduced by combining shutdown and inverter functions, then device complexity and cost are reduced, but the reliability of rapid shutdown functionality may be compromised

Engineering Contradiction:

Improvenumber of transistorsVSAvoidrapid shutdown functionality

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The rapid shutdown control circuit is integrated with the inverter control circuit, allowing a single control system to manage both power conversion and rapid shutdown functions, ensuring reliable shutdown capability while reducing component count

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control circuit monitors the operational state of the inverter transistors and can rapidly shut down power conversion by controlling these same transistors, providing feedback-based safety assurance without additional shutdown components

Inventive Principle:

Principle #23Feedback

3Power

If a three-phase half-bridge inverter architecture with 6 transistors per inverter is used, then power conversion capability is improved, but the total number of transistors multiplies with each additional inverter

Engineering Contradiction:

Improvepower conversion capabilityVSAvoidnumber of transistors

Core Design Contradiction:

PowerVSQuantity of substance

Solution Approach 1:

The patent divides the inverter system into modular power units, each handling a specific photovoltaic module or string. Each module-level inverter is a self-contained unit that converts DC to AC independently, allowing scalable system design without multiplying transistor counts across centralized inverters

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from a centralized inverter architecture to a distributed module-level inverter architecture. This dimensional shift in system organization allows power conversion capability to be maintained while reducing the total transistor count by eliminating redundant control and shutdown components across multiple centralized units

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 solution effectively reduces the complexity and cost of solar power systems while meeting rapid shutdown requirements by minimizing the number of transistors and integrating quick-disconnect functionality, enhancing the efficiency of the power conversion process.

Implementation Method 1

a distributed inverter consisting of and an associated transistor switches connected to either the positive or negative output terminal of the at least two photovoltaic modules

Methodology Applied

Scientific EffectMOSFET switching:

Data Source

PatentUS10848050B2Module-level shutdown electronics combined with module-level inverter for photovoltaic energy systems

Publication Date: 2020.11.24 GENESEE VALLEY INNOVATIONS LLC

AI summary

A power system includes at least one power unit, and each power unit has a direct current power source comprising at least two photovoltaic modules connected in series, each module having a positive and a negative output terminal, and a distributed inverter consisting of and an associated transistor switches connected to either the positive or negative output terminal of the at least two photovoltaic modules, and an alternating current power output. A power system has at least two power units, and each power unit has a direct current power source of at least one photovoltaic modules, and at least two transistor switches, wherein each power unit produces one polarity of voltage, used for generating alternating current power.