| With the continuous increase of the permeability of renewable energy,its volatility and intermittent characteristics lead to the decrease of the power supply reliability of the grid.Meanwhile,due to the introduction of a large number of power electronic equipment,the inertia of the system decreases,resulting in insufficient frequency support.When the grid suffers from a large disturbance,it is easy to cause power outage accidents or new energy chain off-grid.In view of the above problems,consider to introduce the mobile energy,and the stable operation of the new energy grid is maintained through the study of mobile energy configuration and control strategy.Firstly,the disadvantages of the main power generation units in traditional mobile energy are analyzed,and a variety of alternative solutions are proposed,such as fuel cells,energy storage and so on.By studying the characteristics of the above power supply module,the parameters of the internal power generation unit of mobile energy are designed.The maximum load demand and maximum vehicle load were taken as constraints,and the mobile energy mix was planned by focusing on economy and mobility respectively.The energy density and power density were taken as evaluation indexes to analyze the resulting schemes.On this basis,considering the capacity demand of the new energy system for mobile energy,the minimum inertia demand of the system is calculated under the constraint condition that the frequency deviation and change rate are within the safe range.By analyzing the equivalent inertia of each module of the mobile energy,the minimum capacity limit of the mobile energy in the system is given.Secondly,on the basis of the completion of the mobile energy internal power generation unit planning,the control strategy is deeply studied.Aiming at the diesel generator,fuel cell,photovoltaic,energy storage and other power generation modules existing in mobile energy,a hybrid power generation combination scheme under different conditions is proposed.In order to improve the reliability of power supply,the control scheme of mobile energy off-grid connection is studied and verified by simulation.Then,the optimal access location of mobile energy in the system is studied.According to the definition of N-1 security domain,the mathematical model of N-1security domain containing mobile energy is preliminarily listed,and the output unstable modules of photovoltaic,wind power and load in the system are predicted.The optimal allocation strategy of mobile energy access point is proposed under different weather conditions,which takes the sum of the safety margin of each node as the maximum objective function.In order to verify the superiority of the scheme,the 3D security domain model of the system is drawn on Mathematica software by using the visualization technology of dimensionality reduction,and the influence of different access points on the security domain is compared.Finally,according to the above research content,a multi-node microgrid model is built in RTDS,and the core control part of mobile energy is realized by DSP.Hardwarein-the-loop experiment is carried out to verify the effectiveness of the proposed control strategy under different operation modes. |
