Dynamic Modeling Of Gas-fired Internal Combustion Generator Sets Based On Modelica/Dymola

Modeling and simulation are the main methods to study the planning,design,operation and control of distributed integrated energy systems.Usually,it is necessary to build the equipment model library involved in the system,integrate the equipment model into the system model and simulate the corresponding operating conditions.As a multi-energy coupling distributed power supply,it is very important to study the dynamic following and coupling characteristics of thermal,pneumatic and electric parameters of gas-fired internal combustion generator sets under different operating conditions,identify and quantify the association rules and structural parameters in the process of different energy changes.And it is essential for the stability simulation and electromechanical transient simulation of distributed integrated energy systems in grid-connected or off-grid operation.Therefore,this paper has done the following research:Firstly,based on the study of the operation mode of gas-fired internal combustion generator sets,it is determined that the optimal control of the generator sets can be achieved in the mode of following the electric load(FEL)or the mode of following the thermal load(FTL).However,most of the current studies focus on the modeling of gas-fired internal combustion generator sets under the mode of following the electric load(FEL).Secondly,based on the components and operating mechanism of the gas-fired internal combustion generator sets,the internal combustion engine is divided into pipeline modules(intake manifold and exhaust pipe)and component modules(exhaust gas turbine,compressor,intercooler,cylinder and electronic expansion valve),and the generator is divided into rotor motion module,electromagnetic module and excitation system module.On this basis,using the ideas of core feature extraction,partition aggregation and mechanism modeling,taking into account the requirements of accuracy and generality,the dynamic mathematical models of each module are constructed.This paper uses the sequential module method to build the general mechanism dynamic models(GFEL and GFTL)of the gas-fired internal combustion generator sets in the mode of following the electric load and the mode of following the thermal load on the Modelica/Dymola platform.And the GFTL simulation model can realizedynamic simulation of power parameters such as power generation using flue gas flow control.After that,based on the data collection of gas-fired internal combustion generators in Boluo industrial park of Guangdong province,this paper determines the typical scenarios of gas-fired internal combustion generators in two operating modes from the transient events of distributed integrated energy systems.Then,this paper focuses on the co-simulation method of gas-fired internal combustion generator sets and large power grid,the distribution of measuring points of distributed power supply.Through the interface design between generator sets and power grids,dynamic interaction process and parameter analysis of dynamic model,the feasibility of the proposed simulation model for stability and electromechanical transient simulation in various transient events is qualitatively proved.Furthermore,the dynamic simulation results of the models in various typical scenarios are compared with the simulation results of related literatures,which proves that the model has good simulation accuracy.Finally,this paper quantitatively analyzes the variation of the main parameters of the gas-fired internal combustion generator set(exhaust gas temperature / flow/ pressure,power generation efficiency,generator speed and gas consumption,etc.)and the dynamic coupling relationship between the parameters.