Technology And Application Of Flexible Power Distribution Based On Virtual Machine

With the energy shortage and environmental problems become increasingly serious,the clean-energy-based distributed energy resources(DERs)have been gradually developed.These distributed energy sources include distributed generation devices(DG)such as solar power and wind power generation,and distributed energy storage devices(DS)such as flywheel energy storage and super capacitor energy storage,etc.With these distributed energy sources gradually accessing the distribution network in a large number,the distribution network is gradually converting from the traditional passive distribution network to the active distribution network.This conversion puts forward higher request to the distribution device,the original rigid distribution devices in the traditional passive distribution network cannot fully meet the requirements of efficient and stable operation of the power grid.Distribution networks require more flexible and controllable power distribution devices that have met the various needs.On the basis of this,aiming at the demand of the distribution network for the active distribution network,this paper studies the flexible power distribution technology in the active distribution network,and proposes a fully flexible power distribution device based on the virtual motor technology.The virtual motor control technology with excellent performance is incorporated into the device,and the main circuit topology and its control are given..Moreover,the important electrical parameters and their control parameters are optimized and analyzed.The PSCAD simulation software is given,with a variety of operating conditions,and by the RT-LAB platform a HIL simulation results are obtained,which verifies the correctness and effectiveness of the proposed device.The main contents of this paper are:(1)A new type of fully flexible power distribution device based on virtual motor technology with energy storage is proposed for the demand of power distribution equipment.The five components of the device include the grid-connected stage,energy storage stage,isolation stage,AC load stage and DC load stage,and the virtual motor technology are applied to the device,which introduced the damping inertia,and enhanced the device anti-perturbation capability.(2)The parameters of the fully flexible power distribution device proposed in this paper are optimized and designed.The important electrical parameters of the main circuit including the grid-connected inductance,DC-side capacitor,high-frequency transformer leakage inductance and AC side LC filter are optimized.Moreover,according to the principle of small disturbance analysis,the important control parameters optimization analysis of the interface device are carried out.(3)A multi-source network simulation system based on flexible power distribution device is set up.A micro-grid containing a variety of distributed generation and distributed energy storage with detailed models is constructed,which accesses to the low-voltage distribution network through the flexible power distribution device.In the PSCAD simulation software,a large number of simulation conditions of the flexible power distribution device under multi-source network are carried out and the results are analyzed.The simulation conditions mainly include the consideration of micro-grid power surplus,power balance or under-power when the steady-state operation of the device;what's more,the small perturbation and large disturbances under the operation,power quality problems of the network side and load side have been taken into consideration.(4)Using the RT-LAB experimental platform to obtain the experimental results of the application of the device in the active distribution network,the experimental platform is introduced,and the experimental waveform of the flexible power distribution device in the case of grid connection is given.The validity and feasibility of the proposed flexible power distribution device are verified.