Research On Microgrid Droop Control Strategy And A New Type Of Microgrid

The Power system mainly concentrated power generation, large-scale long-distancetransmission network system based. But in recent years with the increasing power load, powergrids have been expanding, and thus ultra-large-scale power systems are also becomingincreasingly apparent disadvantages, high cost, operation difficult, difficult to adapt to theincreasingly high user safety and stability requirements as well as diverse of the demand forelectricity supply. The micro-grid independence, flexibility, interactivity and economybrought to circumvent the lack of large power grids. The micro-grid control is the keytechnology of micro-grid, is to ensure that micro-grid functions to achieve a necessaryprerequisite. Droop control in the control strategy can make micro-grid, high reliability,communications systems rely on a small and more flexible operation mode, etc. In this paper,micro-grid droop control were studied, analyzed the droop control principle and its controlprocess, and through simulated microgrid islanding operation mode of operatingcharacteristics and micro-grid frequency and voltage regulation. Articles in the finalpreliminary exploration of the new micro-grid Energy Surety Microgrid basic concepts,structure, composition, and advantages and disadvantages. The main contents are as follows:(1) Describes the micro-grid research trends in the world, as well as our country’sresearch and development of micro-grid microgrid significance. A brief description of thebasic micro-grid structure and composition of components, and lists the microgrid in the studywhen the depth of the key technology and its development, especially for micro-grid controltechnologies do understand.(2) First introduced micro-power operating modes in several different control methods,there are grid mode, P/Q control and islanding mode U/f control and droop control, build itscontrol structure diagram and analyzed. Then from the micro-level grid lists out several majormicrogrid control strategy would have equal control, master-slave control, based onmulti-agent technology control and management system based on power control strategy, thefirst two were analyzed according to structure, the latter two of its principles are brieflyanalyzed.(3) Derived by way of example the principles of droop control and P/f droopcharacteristics and Q/U droop formulas and curves at the same time change the power droopcharacteristic is derived, for changing the active power P/f droop characteristics and changesin the reactive Q/U droop characteristics to draw final conclusions. (4) Describes the use of peer microgrid control and micro power inverter with droopcontrol schematics, control charts and explains the role of each part. Establishment ofmicro-grid island operation small signal model, consider the model network load and theinverter state space properties. In a three-node, three loads, two island operation consisting ofmicro-power micro-grids, for example, the feature value analysis and inMATLAB/SIMULINK environment simulation analysis, the following conclusions: Thedisturbance load or power grid frequency and voltage will decline the offset can be adjustedby the inverter reactive power, active set load power allocation parameter adjustment, in orderto achieve no difference adjustment; Active and reactive droop on the micro-grid stabilitycoefficient greater impact; electrical point away from the disturbance in the transient processof micro-power imbalance in power have fewer commitments; micro power by automaticallyadjusting the output power to achieve micro-power (DG) and the load of the plug.(5) A brief introduction of energy-guaranteed micro-grid (Energy Surety Microgrid) therole of research direction and made for the purpose, the new grid to achieve five guaranteedelements: energy security, reliability, sustainability, system security and economy. Make upthe elements of the current can only achieve its role among the individual deficiencies. Itssystems model proposes a preliminary assumptions are described theoretically analyzed, itsbasic components and assemblies made of the role of vision, and finally consider the EnergySurety Microgrid some of the challenges to be faced and the next steps needed to solve theproblem.