Inverter Power Stabilization via Gain Offset Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy management systems for photovoltaic power generating systems face instability in output power due to fluctuations in power generation, leading to complex and unstable control methods that fail to maintain constant power output.
Innovation Solution
An energy management system with a direct-current voltage bus, a power generating device, bidirectional DC-DC converters, and an inverter, where the gain of voltage change to current change in the inverter is equal to that in the bidirectional DC-DC converter, and a controller adjusts the offset of gain characteristics to stabilize output power by equalizing the gains of both components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the slope of voltage-current characteristics of power supply units is changed to suppress variation in direct-current bus voltage, then voltage stability is improved, but control complexity increases and system stability deteriorates
Solution Approach 1:
The patent changes the control parameter from slope adjustment to offset adjustment of voltage-current characteristics. The controller adjusts the offset value of the voltage-current characteristics of each power supply unit based on the detected direct-current bus voltage, rather than changing the slope. This parameter change simplifies the control method while maintaining voltage stability.
Solution Approach 2:
The patent implements a feedback control mechanism where the controller detects the direct-current bus voltage and uses this information to adjust the offset of voltage-current characteristics of power supply units. This closed-loop feedback ensures voltage stability while using a simple and stable control approach.
2Reliability
If the slope of voltage-current characteristics is adjusted to maintain constant power output, then power stability is improved, but control complexity increases
Solution Approach 1:
The patent changes the control parameter from slope adjustment to offset adjustment. By adjusting the offset of voltage-current characteristics based on detected bus voltage, the system maintains constant power output with a simpler and more stable control method.
Solution Approach 2:
The controller detects the direct-current bus voltage and adjusts the offset of power supply unit characteristics accordingly, creating a feedback loop that ensures constant power output while avoiding complex control mechanisms.
3Stability of the object's composition
If complex control methods are used to suppress voltage variation, then voltage stability is improved, but system stability deteriorates
Solution Approach 1:
The patent simplifies the control parameter from slope adjustment to offset adjustment of voltage-current characteristics. This parameter change results in a control method that is both simple and stable, improving overall system reliability while maintaining voltage stability.
Solution Approach 2:
The feedback mechanism adjusts offset values based on detected voltage, providing a stable and reliable control approach that avoids the instability associated with complex control methods.
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 configuration allows for simple and stable control of inverter output power, maintaining stability even with varying power generation, and can be easily controlled to adjust to changes in power generation environments.
Implementation Method 1
The bidirectional DC-DC converter is connected to the secondary battery and converts a direct-current voltage delivered between the secondary battery and HVDC bus into a predetermined constant voltage
Implementation Method 2
an inverter connected to the direct-current voltage bus and configured to convert the direct-current voltage received from the direct-current voltage bus into an alternating-current voltage
Implementation Method 3
a photovoltaic power generating system that uses power generated by solar panels
Data Source
AI summary
An energy management system that includes a power generating device, bidirectional DC-DC converter, and inverter connected to an HVDC bus. A gain of a voltage change to a current change in the bidirectional DC-DC converter is equal to the gain in the inverter. When an output power of the inverter or the bidirectional DC-DC converter varies in response to a variation in an output current of the power generating device, the energy management system can control the output power of the inverter to conform to a target value by adjusting an offset of gain characteristics of the bidirectional DC-DC converter to gain characteristics of the inverter. As a result, the energy management system is capable of stabilizing the output power of the inverter.