AC Feed-In Blocking Circuit for Zero-Export Solar Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In interconnected alternating current networks, existing technologies fail to effectively control power propagation direction, leading to instability and economic inefficiencies in solar systems connected to the public grid, where power generation does not align with consumption patterns, resulting in reduced profitability due to lower feed-in tariffs and potential grid instability.
Innovation Solution
An electronic circuit, known as the NEBL, is used to block power flow from a consumer unit into the public grid while allowing power flow from the grid to the unit, utilizing thyristors and control logic to determine power flow direction and enable temporary storage of excess energy in a battery for later use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If inverters are connected to the public power grid, then solar power can be fed in, but grid stability may be negatively impacted
Solution Approach 1:
The invention extracts the power feed-in function from the grid connection by blocking the reverse power flow path. This allows solar systems to operate independently from grid stability concerns while maintaining the ability to generate and consume power locally, effectively removing the source of grid instability caused by distributed inverters
Solution Approach 2:
The blocker device segments the electrical network into two independent AC networks, separating the solar system from the public grid. This segmentation allows each network to operate independently, enabling power generation without compromising grid stability while maintaining bidirectional charge carrier flow capability
2Ease of operation
If power generation is increased to match consumption peaks, then self-sufficiency improves, but the mismatch between generation and consumption patterns reduces profitability
Solution Approach 1:
The invention implements preliminary action by storing excess power generated during sunny hours in batteries before consumption peaks occur. This allows the system to have energy ready for use during high-demand periods without needing to increase generation capacity, maintaining self-sufficiency while avoiding the profitability loss of generating power that cannot be consumed
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
The NEBL minimizes power fed into the public network, optimizing self-sufficiency and reducing grid instability by allowing energy storage and retrieval, thereby enhancing the economic viability of solar systems and maintaining grid stability.
Implementation Method 1
One pair of thyristors (with the same diode direction) is connected in series to one another as a thyristor pair... One thyristor pair is responsible for the inward charge flow (according to its inherent diode effect), and the other thyristor pair is responsible for the outward charge flow
Data Source
Figure 1
Figure 2
Figure 2
AI summary
The grid feed-in blocker is typically used in the operation of photovoltaic systems where the operator wants to achieve zero feed-in of the generated electrical power. The patent describes a device in the form of an electronic circuit, typically for operation in a 230-volt AC network, which prevents the feed-in of electrical power from a residential, commercial, or subnetwork into the public grid without restricting the power consumption of the subnetwork from the public grid. This allows a maximum proportion of the internally generated power to be stored for later self-consumption. The feed-in blocker regulates the feed-in blocking automatically, precisely, and with each half-wave of the sine wave. Power control of the inverter used is no longer necessary to achieve zero feed-in.The power feed-in blocker is typically installed between the standard 16A household fuse and the consumer units. An alternative application involves housing the power feed-in blocker in a mobile distribution strip. Consumer units can be selectively plugged into this strip to prioritize the supply of photovoltaic power to individual devices.