Photovoltaic Inverter Interface Voltage Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Photovoltaic systems face inefficiencies and high costs due to the need for inverters to handle high open-load voltages, leading to increased energy losses and higher costs for silicon components.
Innovation Solution
A photovoltaic interface system that isolates the photovoltaic array from the inverter and modulates the load to reduce the voltage applied to the inverter, using a switching segment to gradually connect and disconnect the array, allowing the use of lower-voltage silicon in inverters and reducing exposure to damaging open-load voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If inverters are designed to handle high open-load voltages (1400V), then they can accommodate the full voltage range of photovoltaic arrays, but they incur substantially more losses and cost substantially more than inverters designed for lower voltages
Solution Approach 1:
A DC-DC converter is introduced as an intermediary device between the photovoltaic array and the inverter. The converter accepts high-voltage input from the array (up to 1400V open-load) and outputs a regulated lower voltage to the inverter, allowing the inverter to be designed for lower voltage operation while still accommodating the full array voltage range. This mediator isolates the inverter from high-voltage stress and associated losses.
Solution Approach 2:
The voltage conversion function is segmented into two separate stages: first, the DC-DC converter handles the high-voltage to low-voltage conversion from the array; second, the inverter handles only the lower voltage conversion to AC output. This segmentation allows each component to be optimized for its specific voltage range, improving overall system efficiency.
2Reliability
If inverters are designed for higher voltages to accommodate open-load conditions, then they can handle all operating states, but they cost substantially more than inverters utilizing lower-voltage silicon
Solution Approach 1:
The DC-DC converter serves as a protective intermediary that isolates the inverter from high-voltage open-load conditions. The inverter only needs to handle the regulated lower voltage output from the converter, enabling the use of lower-voltage (and lower-cost) silicon devices while still accommodating all array operating states through the converter's voltage regulation.
Solution Approach 2:
The DC-DC converter performs preliminary voltage regulation before the power reaches the inverter. By pre-converting the high voltage to a lower, stable voltage level, the converter prepares the power in advance, allowing the inverter to be designed for lower voltage applications and reducing component costs.
3Power
If photovoltaic arrays operate at high open-load voltages, then they can generate higher voltage output to reduce current and associated costs, but the voltage drops substantially once power is drawn from the arrays
Solution Approach 1:
The DC-DC converter incorporates feedback control mechanisms that continuously monitor the input voltage from the photovoltaic array and adjust the conversion ratio accordingly. When the array operates at high open-load voltage, the converter detects this condition and adjusts its operation to maintain stable output voltage to the inverter, compensating for the array's voltage drop under varying load conditions.
Solution Approach 2:
The DC-DC converter provides dynamic voltage regulation, continuously adapting its conversion ratio in response to changing array voltage conditions. This dynamic adjustment allows the system to accommodate the array's natural voltage variations from open-load to loaded states while maintaining stable operation of the inverter.
Data Source
AI summary
A photovoltaic system, method and apparatus are disclosed. In an exemplary embodiment, the system includes a first and second inputs adapted to couple to a first and second rails of a photovoltaic array; an inverter configured to convert DC power from the photovoltaic array to AC power; and an interface portion coupled to the first and second inputs and the inverter, the interface portion configured to isolate at least one of the first and second inputs from the inverter and to modulate an application of a voltage from the photovoltaic array to the inverter so as to increase a load on the photovoltaic array and to reduce the voltage applied from the photovoltaic array to the inverter.