Photovoltaic Inverter Control for 30 ms Reactive Power Response
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Solution Overview
Problem
Current dynamic reactive power compensation resources, such as static var generators, have high initial construction, power consumption, and maintenance costs, and existing communication technologies cannot meet the 30-millisecond dynamic reactive power compensation response time required by national standards.
Innovation Solution
A method for implementing a fast power response in a new energy power plant using a power plant-end power control apparatus that determines whole-plant reactive and active power target values based on real-time grid signals, and transparently transmits power control instructions to subarrays, reducing communication latency and enabling a 30-millisecond reactive power response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SVG (static var generator) is used to perform fast reactive power coordinated control, then the dynamic reactive power compensation response time requirement (≤30 milliseconds) is met, but the initial construction investment cost, power consumption, and operation and maintenance cost increase
Solution Approach 1:
The patent makes the inverter perform both active power generation and reactive power compensation functions simultaneously. The inverter can dynamically switch between or combine both functions, eliminating the need for a separate dedicated SVG device. This multi-functionality approach reduces overall system cost and energy consumption while maintaining the required ≤30ms response time for reactive power compensation.
Solution Approach 2:
The patent merges the reactive power compensation function with the inverter system. Instead of having separate SVG and inverter systems, the reactive power control capability is integrated into the inverter's power conversion system, allowing unified control and reducing redundant equipment, thereby lowering initial construction costs and operational energy consumption.
2Reliability
If SVG is used to perform fast reactive power coordinated control, then the dynamic reactive power compensation response time requirement (≤30 milliseconds) is met, but the initial construction investment cost and operation and maintenance cost increase
Solution Approach 1:
The inverter is designed to provide both active power generation and reactive power compensation capabilities within a single device. This eliminates the need for separate SVG equipment, significantly reducing initial construction investment costs while maintaining the required ≤30ms response time performance through integrated control.
Solution Approach 2:
The patent utilizes the existing inverter hardware and control infrastructure to perform reactive power compensation, effectively copying the SVG's function using already-deployed equipment. This approach avoids additional capital expenditure on separate SVG systems while achieving the same technical performance.
3Reliability
If TCP communication is used between power plant-end power control apparatus and target power control instruction execution apparatus, then communication reliability is improved, but communication latency increases (at least 20 milliseconds due to encoding/decoding and handshakes)
Solution Approach 1:
The patent extracts the essential control instruction transmission function from the complex TCP communication protocol. By using simplified communication protocols or direct communication mechanisms that bypass extensive encoding/decoding and handshake procedures, the system achieves the required ≤30ms response time while maintaining sufficient communication reliability for control purposes.
Solution Approach 2:
The patent skips the time-consuming TCP handshake and extensive encoding/decoding phases by using more direct communication methods. The control system implements streamlined communication that rushes through the essential data transmission needed for reactive power control, achieving sub-30ms latency without sacrificing the reliability needed for safe operation.
Data Source
AI summary
This application discloses a method for implementing a fast power response and a power plant. The method is applied to a power plant-end power control apparatus, and includes determining a whole-plant reactive power target value and/or a whole-plant active power target value of the power plant. The method also includes determining, based on the whole-plant reactive power target value and/or the whole-plant active power target value, a second power control instruction readable to each photovoltaic inverter or power conversion system in the power plant. The method further includes delivering, through a subarray controller or a subarray communication device over an Ethernet network and/or a field bus network, the second power control instruction to each photovoltaic inverter or power conversion system indicated by address identifier information carried in the second power control instruction, so that each photovoltaic inverter or power conversion system makes a fast power response based on the second power control instruction.