A cooperative control method for microgrid grid-following and grid-forming converters based on event-triggered improved consensus algorithm

In isolated microgrid system, the primary control of grid-following (GFL) converters and grid-forming (GFM) converters causes deviations in voltage and frequency, necessitating the addition of secondary control to eliminate errors. Traditional distributed secondary control based on consensus algorithm imposes a significant communication burden on the system and requires high performance communication networks. This paper proposes an event-triggered consensus algorithm, which incorporates the generated voltage and frequency compensation signals into the primary droop control of GFM and GFL. This effectively eliminates the steady-state errors caused by primary control in the GFM and GFL hybrid system, achieving coordinated control of voltage and frequency. Additionally, the event-triggered mechanism reduces data exchange between inverters, thereby alleviating the communication load of the system. First, the principles of the consensus algorithm and event-triggered mechanism are introduced. Then, a simulation is conducted on an isolated microgrid system comprising three GFM inverters and one GFL inverter operating in parallel using the MATLAB/Simulink platform to validate the effectiveness of the method.