PV Energy Storage Coupling for Power Fluctuation Smoothing
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Solution Overview
Problem
Conventional photovoltaic systems experience unstable power output due to power fluctuations, leading to grid instability, and existing power control methods based on prediction models are complex and impractical.
Innovation Solution
A device and method that integrates an energy storage module with a photovoltaic assembly through a point of common coupling, using a bidirectional power converter and a dual regulator control algorithm to manage current fluctuations, allowing for rapid power regulation and smoothing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If photovoltaic assemblies are connected directly to the grid through photovoltaic inverters, then the system structure is simple, but the grid experiences power jumps and instability due to photovoltaic power volatility
Solution Approach 1:
The patent introduces an energy storage module as an intermediary component between the photovoltaic assembly and the grid. This mediator absorbs power fluctuations from the photovoltaic side and provides stable power to the grid, resolving the contradiction by adding a buffering layer that improves grid stability without significantly complicating the overall system structure
2Reliability
If prediction model-based control methods are used to suppress power fluctuation, then power smoothing can be achieved, but the algorithm implementation becomes complex and less practical
Solution Approach 1:
The patent employs a feedback control mechanism where the controller continuously monitors the power output from the photovoltaic assembly and adjusts the energy storage module's charging/discharging operations accordingly. This real-time feedback approach achieves effective power smoothing without requiring complex prediction models, maintaining algorithm simplicity while improving reliability
3Reliability
If energy storage modules are used to regulate power fluctuation rapidly, then photovoltaic power can be smoothed and controlled, but the system complexity increases
Solution Approach 1:
The patent merges the energy storage module with the existing photovoltaic inverter system, integrating multiple functions into a unified structure. The energy storage module shares the common coupling point with the photovoltaic assembly, allowing rapid power fluctuation control while minimizing additional system complexity through functional integration
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 solution effectively transforms a photovoltaic system into an energy storage system, rapidly regulating and smoothing power fluctuations, extending the life of energy storage modules and reducing maintenance costs while enhancing grid stability.
Implementation Method 1
A bidirectional power converter is disposed between the energy storage module and the point of common coupling
Implementation Method 2
photovoltaic assemblies are connected to the grid directly through photovoltaic inverters
Data Source
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AI summary
The disclosure provides a device (20) and method for smoothing and controlling power fluctuation of a photovoltaic assembly (11) and a photovoltaic energy storage system. The device (20) includes an energy storage module (21), a bidirectional power converter (22), an acquisition module (23), and a control module (24). The energy storage module (21) is connected to a photovoltaic side of a photovoltaic inverter (12) and an output end of the photovoltaic assembly (11) through a point of common coupling. The bidirectional power converter (22) is disposed between the energy storage module (21) and the point of common coupling. The acquisition module (23) acquires first and second current feedback values. The control module (24) calculates a second current change rate and generates a control signal controlling a first current based on a dual regulator control algorithm when the second current change rate exceeds a second current change rate limit value.