Frequency Stabilizing Apparatus for Isolated Power Systems
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Solution Overview
Problem
Existing frequency stabilization methods for isolated power systems, particularly in small-scale isolated systems, face challenges in effectively managing demand and supply imbalances, leading to prolonged frequency deviations due to the limitations of power generators and storage batteries in responding to rapid changes in demand and supply fluctuations.
Innovation Solution
A frequency stabilizing apparatus that includes a first calculator for generating a command value based on demand and supply imbalances, a second calculator for estimating frequency changes, and a command value calculator to adjust the storage battery output, allowing for precise control of power adjustments to stabilize the frequency by using both interconnection point tidal current values and frequency deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If power generator output is adjusted to meet demand fluctuations, then power supply balance is improved, but response speed is insufficient when demand changes rapidly
Solution Approach 1:
The storage battery performs preliminary action by providing frequency stabilization power before the power generator can respond to demand fluctuations. The control device calculates the frequency stabilization power as the difference between actual demand fluctuations and generator response capability, enabling the storage battery to act in advance and compensate for the generator's slow response.
2Reliability
If storage battery output is increased to follow demand fluctuations, then frequency stabilization is improved, but device complexity increases
Solution Approach 1:
The control system segments the power stabilization function into two independent parts: the power generator handles bulk power supply balance, while the storage battery handles frequency stabilization. This segmentation allows each component to specialize in its function, improving overall reliability without requiring the storage battery to handle all fluctuations, thus managing complexity.
Solution Approach 2:
The control device acts as an intermediary that calculates the frequency stabilization power by comparing actual demand fluctuations with generator response capability. This intermediary function coordinates between the generator and storage battery, enabling the storage battery to provide precise frequency stabilization without requiring complex direct control of the entire power system.
3Speed
If power generator rated output is increased to follow high change speed, then adjusted speed is improved, but cost and system size increase
Solution Approach 1:
Instead of increasing the power generator's rated output capacity to handle all demand fluctuations, the system applies partial action by using the storage battery to handle only the frequency stabilization portion of the fluctuations. This allows the generator to operate at optimal capacity while the storage battery provides the additional speed response needed for high change speed requirements.
Data Source
AI summary
A frequency stabilizing apparatus includes a power detecting method control amount calculator, a frequency detecting method control amount calculator, and a command value calculator. The power detecting method control amount calculator generates a first command value based on demand and supply imbalance of power in an isolated island system. The frequency detecting method control amount calculator generates a second command value based on a change in a frequency of the power in the isolated island system. The command value calculator generates a command value to be given to a first storage battery based on the first command value and the second command value.