Wind Farm Inner-Park Network Voltage Adjustment
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Solution Overview
Problem
In wind farms, ensuring reliable self-supply of electrical energy when there is no connection to a land-based energy supply network is challenging due to unpredictable reactive power requirements caused by unknown cable parameters and limited capacity of diesel generators to provide charging power.
Innovation Solution
Operating the inner-park network at a lower second operating voltage than normal, reducing the reactive power requirement and its variance, allowing for reliable self-supply even with a single diesel generator, by disconnecting from the energy supply network and using generators like diesel generators to provide power directly to the network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the inner-park network is operated at normal operating voltage (first operating voltage), then the power transmission capability is maintained, but the reactive power requirement and charging power become unpredictable and exceed diesel generator capacity
Solution Approach 1:
The patent applies dynamics by making the operating voltage adjustable rather than fixed. The inner-park network can operate at a first operating voltage during normal grid-connected operation and switch to a second, lower operating voltage during islanded operation with diesel generators. This dynamic voltage adjustment allows the system to adapt to different operational modes and resolve the contradiction between maintaining power transmission capability and ensuring reliable self-supply with limited generator capacity.
Solution Approach 2:
The patent directly applies parameter changes by modifying the operating voltage parameter of the inner-park network. During islanded operation, the voltage is reduced from the first operating voltage to a second operating voltage that is specifically selected to limit the charging power of cable sections to a predetermined maximum value. This parameter change ensures that diesel generators can reliably meet the reactive power requirements without exceeding their capacity.
2Adaptability or versatility
If diesel generators are used to cover the wind farm's own requirements, then energy independence is achieved, but the reactive power requirement cannot be precisely predicted due to unknown cable parameters
Solution Approach 1:
The patent applies preliminary action by pre-calculating and establishing a relationship between operating voltage and maximum charging power of cable sections. Before actual islanded operation begins, the system determines a second operating voltage that ensures the charging power remains within a predetermined maximum value that diesel generators can handle. This preliminary determination eliminates the need for precise real-time measurement of cable parameters during operation.
Solution Approach 2:
The system incorporates feedback mechanisms to monitor the actual charging power and reactive power requirements during islanded operation. Based on this feedback, the operating voltage can be adjusted to maintain reliable self-supply. The feedback loop ensures that even with uncertainties in cable parameters, the system remains within operational limits and maintains energy independence.
3Reliability
If the operating voltage is reduced to a second operating voltage, then the reactive power requirement and charging power are reduced, but the power transmission capability is limited
Solution Approach 1:
The patent resolves this contradiction through dynamic voltage adjustment based on operational mode. During normal grid-connected operation, the system operates at the first, higher voltage to maximize power transmission capability. During islanded operation with diesel generators, it switches to the second, lower voltage to ensure reliable self-supply within generator capacity limits. This dynamic switching eliminates the need to permanently sacrifice power transmission capability while ensuring reliability when needed.
Data Source
Figure 1
Figure 2a~2b
Figure 2c~2d
AI summary
The invention relates to a method for operating an electrical circuit (10) for a wind farm, wherein the electrical circuit (10) has a first network (16), wherein the first network (16) is operated with a first operating voltage in normal operation, in which at least one generator (13) driven by a wind turbine (11) is coupled to the first network (16), characterized in that the first network (16) is operated with a second operating voltage in a second operating mode different from normal operation, wherein the second operating voltage is lower than the first operating voltage.