Inverter Output Voltage Control for Fast Active Power Response
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Solution Overview
Problem
The control speed of output active power in photovoltaic grid-connected inverters using conventional virtual synchronous generators is slow, limiting their application scenarios and scope.
Innovation Solution
An inverter system with a direct current conversion circuit, inverter circuit, and controller that adjusts output voltage based on reactive voltage control amounts to quickly control actual output active power, enabling fast power scheduling responses and voltage/frequency support for the power grid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If network construction control based on virtual synchronous generator is used, then voltage and frequency support for power grid is provided, but control speed of output active power is slow
Solution Approach 1:
The patent applies dynamics by making the control mode switchable between static (virtual synchronous generator) and dynamic (output voltage control) modes. The controller dynamically selects the appropriate control mode based on grid conditions, enabling the inverter to transition from slow conventional control to fast response control when rapid active power adjustment is needed, thus resolving the contradiction between reliability and control speed.
Solution Approach 2:
The patent changes the control parameter from conventional virtual synchronous generator parameters to output voltage parameters (including amplitude and phase angle). By controlling the output voltage of the inverter circuit directly, the system achieves rapid adjustment of output active power while maintaining voltage and frequency support capabilities, effectively resolving the speed limitation of traditional control methods.
2Reliability
If conventional virtual synchronous generator control is used, then grid support function is achieved, but application scenario and scope are limited
Solution Approach 1:
The patent implements multi-functionality by enabling the inverter to operate in multiple modes: virtual synchronous generator mode for traditional grid support, and output voltage control mode for rapid active power adjustment. This dual-mode capability allows the inverter to adapt to diverse application scenarios including grid support, fast power scheduling, and scenarios requiring immediate response to power commands, significantly expanding its applicability scope.
Solution Approach 2:
The patent makes the control system dynamic and adaptive by allowing switching between different control modes based on application requirements. The controller can select appropriate control strategies for different scenarios, making the inverter versatile enough to handle both traditional grid support tasks and modern fast-response power scheduling demands.
Data Source
AI summary
An inverter and a control method for the inverter. The inverter includes a direct current conversion circuit, a direct current bus, an inverter circuit, and a controller. An input end of the direct current conversion circuit is connected to an input end of the inverter, an output end of the direct current conversion circuit is connected to an input end of the inverter circuit through the direct current bus, and an output end of the inverter circuit is connected to an output end of the inverter. The controller obtains a reactive voltage control amount based on actual output active power and reference output active power of the inverter circuit and adjusts an output voltage of the inverter circuit based on the reactive voltage control amount and a reference output voltage.