PQ Level Control for Fluctuating Power Station Stability
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Solution Overview
Problem
Power plants with fluctuating electrical capacity, such as photovoltaic or wind power plants, face challenges in stabilizing limited alternating current networks against rapid changes in power consumption without destabilizing the network, especially when internal combustion generators have slow activation times and mechanical inertia limitations.
Innovation Solution
A method that defines a desired operating range for the network generator in the PQ level, allowing it to efficiently regulate voltage fluctuations by controlling the output of active and reactive power, and manages reserve power through activation and deactivation of additional power sources to maintain stability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If power from the power plant is fed into the AC network to reduce fuel consumption, then fuel consumption of internal combustion generators is reduced, but network stability may be destabilized
Solution Approach 1:
The control device continuously monitors the operating point of the network generator in the PQ level and adjusts the power plant's active and reactive power output accordingly to keep the operating point within the desired operating range, providing real-time feedback control that prevents network destabilization while maximizing renewable energy utilization
Solution Approach 2:
The method controls the output parameters (active power and reactive power) of the power plant to dynamically adjust the operating point of the network generator, changing these parameters to maintain the generator within its stable operating range while accommodating fluctuations in renewable energy generation
2Reliability
If internal combustion generators are activated to cover power consumption increases, then power supply reliability is improved, but activation time delay prevents rapid response
Solution Approach 1:
The method maintains the network generator within a desired operating range that preserves reserve capacity, preparing the system in advance to rapidly respond to power consumption increases without requiring delayed activation of additional internal combustion generators
Solution Approach 2:
The power plant with controllable output acts as an intermediary between load fluctuations and the network generator, absorbing rapid power consumption changes through its fast response capability and preventing the need for immediate activation of slow-response internal combustion generators
3Power
If the network generator operates at maximum capacity to meet power demand, then power supply capability is improved, but ability to regulate voltage fluctuations is reduced
Solution Approach 1:
The method transitions from single-dimensional active power control to two-dimensional control in the PQ level, simultaneously managing both active power and reactive power to maintain the network generator's operating point within a desired range that preserves voltage regulation capability while maximizing power supply
4Loss of energy
If power plant output is increased to maximize renewable energy utilization, then fuel consumption is reduced, but risk of emergency shutdown of internal combustion generators increases
Solution Approach 1:
The control device continuously monitors the network generator's operating point and provides real-time feedback control, adjusting the power plant's output to prevent the generator from operating outside its stable range, thereby maximizing renewable energy utilization while preventing emergency shutdowns
Solution Approach 2:
The method maintains the network generator within a desired operating range that provides a safety margin or cushion, preventing the generator from reaching conditions that would trigger emergency shutdown while still maximizing the utilization of renewable energy from the power plant
Data Source
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AI summary
A method for the operation of a power station of fluctuating electrical performance that is connected, besides at least one voltage-setting system former (3) that outputs active power (P) and reactive power (Q) and at least one load (7), to a limited AC system (1), a desired closed operating range of the system former (3) is defined on the PQ level, in which range the system former is able to efficiently correct fluctuations arising in a system AC voltage on the AC system (1). A present operating point for the system former on the PQ level is ascertained, and an output of active power and reactive power by the power station (8) is controlled such that the operating point of the system former (3) is kept in the desired operating range.