PV Inverter MPPT Boost Control for Lower Switching Loss
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Solution Overview
Problem
Inverters with multiple independent maximum power point tracking (MPPT) boost circuits face high boost ratios and significant switching losses due to voltage differences between input voltages, leading to inefficient power generation.
Innovation Solution
An inverter system that includes a controller to identify and adjust boost circuits with mismatched input voltages, ensuring the total power output remains within a preset threshold, thereby reducing the boost ratio and switching losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple independent MPPT boost circuits are used to handle complex terrain configurations and increase power generation, then power generation capability is improved, but voltage differences between input voltages cause high boost ratios and significant switching losses
Solution Approach 1:
The patent merges multiple independent MPPT boost circuits into a single shared boost circuit structure. Multiple PV arrays with different voltage characteristics can connect to the same boost circuit, and the circuit dynamically adjusts to handle voltage differences without requiring separate boost circuits for each array, thereby reducing overall switching losses while maintaining power generation capability.
Solution Approach 2:
The patent implements dynamic voltage matching and duty cycle adjustment in the shared boost circuit. The control system continuously monitors input voltages from different PV arrays and dynamically adjusts the switching duty cycles to optimize the boost ratio for each array, reducing switching losses under varying voltage conditions while maintaining maximum power point tracking.
2Stability of the object's composition
If the boost ratio is increased to accommodate low input voltages in certain MPPT circuits, then voltage matching is improved, but switching losses increase significantly
Solution Approach 1:
The patent changes the operating parameters of the shared boost circuit dynamically. By adjusting the switching frequency and duty cycle based on real-time voltage measurements from different PV arrays, the system optimizes the boost ratio to minimize switching losses while maintaining adequate voltage matching across all connected arrays.
3Stability of the object's composition
If independent boost circuits are used for each PV array to maintain voltage stability, then voltage stability is improved, but device complexity and switching losses increase
Solution Approach 1:
The patent combines multiple independent boost circuits into a single shared boost circuit that serves multiple PV arrays. This merging reduces device complexity by eliminating redundant components while maintaining voltage stability through dynamic control strategies that adapt to the specific voltage characteristics of each connected array.
Data Source
AI summary
An inverter, a control method of the inverter, and a power system are provided. The inverter includes a DC bus, an inversion circuit, a controller, and multiple boost circuits. An input terminal of each boost circuit is configured to connect to a corresponding photovoltaic unit, output terminals of the boost circuits are connected in parallel and connected to the DC bus, and the inversion circuit is configured to convert DC power outputted by the DC bus into AC power. The controller is configured to: determine, during an operation stage of the inverter, a to-be-adjusted boost circuit from the boost circuits, in response to determining that there is a loss boost circuit in a preset loss condition among the boost circuits; and adjust the to-be-adjusted boost circuit while ensuring that a change threshold for a total power output of the boost circuits is less than a preset adjustment threshold.