The Research On The Operation Characteristic Of CCHP And MicroGrid Composed Of CCHP

The distributed Combined Cooling Heating and Power (CCHP) has highefficiency in energy utilization and low pollution in emitting, and can satisfy differentkinds of energy demands such as cooling, heating and power by the users. MicroGrid,which can flexibly supervise the cooling heating, and power load and increase theeconomic and social benefits, provides a flexible operation platform for distributedCCHP. Aimed at the system structures, control modes, math models and operationrules etc. of CCHP and MicroGrid, this paper carries on the related research work asfollows:The structure characteristic, control modes, and operation rules of a single shaftMicroTurbine are investigated. Aimed at the shortages of flexibleness in control modeand slowness in dynamic respond of a single shaft MicroTurbine rectified by diode, aimproved scheme based on double PWM converter is presented, and the controlmethod based on voltage outer loop and current inner loop is designed. Through thesystem simulation of dynamic characteristic research under different structures, wecan draw a conclusion that, by the double PWM structure, the dynamic performanceof system can be improved, and the direct current fluctuation and the harmonic ofconverter can be decreased.Aimed at the lack of analysis precision of split-shaft MicroTurbine, a dynamicmodel, which use small signal linear approach, is presented for the simulating ofdifferent shafts. Then the control modes of split shaft MicroTurbine are investigated,and the simulation tests are carried on to analyze the operation characteristic underdifferent control modes. The result of simulation can be used as a theory basis for afurther research on the split shaft MicroTurbine.The operation characteristic of MicroGrid, composed of multi MicroTurbines, isinvestigated when the MicroGrid operation mode switches from grid-connected modeto islanding mode under different control strategies. Adopting single master controlstrategy and multi masters control strategy separately, the MicroGrid dynamiccharacteristic under intentional islanding and unintentional islanding is investigated,and the seamless transition condition and influencing factors under MicroGridislanding are studied. Through the research results, the MicroGrid operation and control rules composed of multi MicroTurbines are summarized and a safe andsmooth transition in the process can be achieved.The research about configure selection of different kinds of MicroTuribnes inMicroGrid is carried on. The characteristic parameters such as equipment costs,generating efficiency and noise level etc. are compared. Through the research of theload tracking ability, dynamic characteristic under different types of loads andoperation rules under different MicroGrid topologies, the reference index can beachieved by analyzing the system anti-disturbence ability, evaluating the dynamiccharacteristic and selecting electrical sources.