| In today’s increasingly energy shortage environment,distributed new energy has gradually become an effective means to alleviate energy crisis and environmental pollution due to its own characteristics of clean environmental protection and resource conservation.With the proposal of the "double carbon" goal,offshore oil and gas fields have also begun to actively respond to the call of the state in terms of power consumption and energy management,and actively explore friendly and flexible renewable energy and traditional energy combined power supply technology.However,with the increase of new energy penetration,the pattern of distribution network will change,bringing many uncertainties to the planning and operation of the system.Therefore,when considering the access of new energy,it is necessary to select a reasonable location and capacity for new energy,and also pay attention to the voltage level of power supply,power quality and stability of distribution network.The main research contents are as follows:(1)Aiming at the joint configuration of wind turbine/ photovoltaic/ energy storage connected to offshore oil and gas platforms,combined with the characteristics of offshore wind power and photovoltaic and the existing topological structures,this paper proposes a phased joint configuration strategy for wind turbine/ photovoltaic/ energy storage in two scenarios with superior distribution network and independent operating distribution network.In the process of site selection and capacity determination,we mainly consider the distribution network cluster division,power flow stability,economy,voltage fluctuation,active power loss,the minimum technical output of generators and other conditions.A phased particle swarm optimization algorithm embedded in power flow calculation is proposed and adopted to obtain the optimal access capacity of wind turbine/ photovoltaic/ energy storage at each node through iteration.(2)Aiming at the power quality problem of new energy access to the distribution network,this paper selects the inverter as the research object and proposes a performance enhancing control structure combining linear quadratic optimal control and residual generator.Firstly,the state space model of three-phase inverter and the quadratic optimal controller with fast response speed are established.Secondly,according to the dual prime decomposition and Euler parameterization theory,the performance improvement control structure based on residual generator is obtained.Then,based on the model matching principle,the performance enhancement controller is solved.The introduction of this control architecture can improve the transient response speed and steady-state anti-jamming ability of the system.(3)A node voltage feedback control method based on digital twin and inverter residual capacity was proposed to solve the problem that the steady-state voltage of nodes exceeded the limit or deviated from the given scheduling due to output fluctuation after new energy was connected to the distribution network.Firstly,the supporting principle of the surplus capacity of the inverter on the grid node voltage is analyzed,and then the digital twin feedback control structure is established.When the node voltage deviates from the schedule or even exceeds the limit due to power fluctuation or equipment failure in the distribution network,the reactive power output of each energy storage inverter is optimized in the twin model,and then delivered to the actual energy storage inverter to realize the regulation of the node voltage.To sum up,the new energy location and capacity determination and control strategy proposed in this paper can effectively improve the stability of the entire power grid after the new energy is connected to the distribution network of the offshore oil and gas platform,and achieve the effect of controlling the voltage level and power quality of the distribution network. |
PDF Full Text Request