Research Of Efficiency Optimization And Management For Energy Resource Power In Building DC Microgrid Based On ADR

The renewable energy is needed to be urgently developed and utilized under energy crisis. But the volatility and mutability of green energy has caused the low conversion efficiency hindering their widely use. The core issue of power system operation scheduling is to keep balance between power supply and demand. With the fast growth of the renewable energy, such as wind power and solar, significant impacts and great challenges to traditional scheduling and control mode have been made to grid. In recent years, the concepts of power balance based on auto-demand response are proposed in the world microgrid, it is built to promote renewable energy accommodation and to reduce the pressure of grid permeability limitation. Electric users change their original power consumption pattern response to the price signal or inspiration signal from power grid based on automatic demand response(ADR), and participate in power system operation actively, in order to maintain power balance between supply and demand, and load shifting. There is great potential for building resident electricity users to participate in demand response, and related studies and practices have been done in recent years.However, the current studies mainly focused on implementation mechanism and power pricing strategy. Compared with other typical load, the building loads have dynamic nonlinear and strong coupling, it isn’t allowed to affect the normal life of residents based on ADR, the traditional demand response programs cannot be applied in building DC microgrid directly.In this thesis, the intelligent village load resources in building DC microgrid has been brought into scheduling system of power grid, by controlling the resident load actively, the shifting is adopted to reduce the influence of power grid, while cutting electricity costs for industrial users. The work is oriented to portable devices, power generation equipment, transferable equipment, charging equipment, energy storage device.In the work, load operation characteristics form intermittent to continuous are analyzed, ADR based load scheduling is associated with resident power load. Under the constraint of user’s comfort, the scheduling methods are researched of load dispatching to ensure both economic target and stability target of building DC microgrid. The proposed methods cut electricity costs for users and expand load type of ADR, the generation power and energy efficiency ratio of wind-PV power is increased, promote stability and renewable energy accommodation of power grid. The main research in the thesis can be list as fellow.1. Efficiency optimization and output power increase for switch reluctance wind power generator DC micro power supply with soft magnetic material.Working mechanism and mathematical model of Switch Reluctance wind power Generator(SRG) DC micro power supply based on soft magnetic material is analyzed, To optimize the efficiency of SRG, the cause of the loss in SRG and the impact on efficiency are studied. The main attentions are focused on combined control strategy, form the current soft chopper control strategy in the stage of low wind speed, to the angular position control strategy in the stage of high wind speed. A piece wise Nonlinear dynamic adaptive control strategy was adopted to realize micro power efficiency optimization. 1)According to the wind turbines power capture mechanism, the characteristics of the biggest wind power, variable perturbation step climbing search method are research, and the dynamic nonlinear MPPT(Maximum wind Power Point Tracking) and excitation with constant voltage is adopted during the period when it is less than rated wind speed. 2) The all-region Boost excitation mode in low wind speed field, excitation with constant voltage or adaptive variable voltage excitation are implemented, to maintain high movement counter electromotive force and big excitation current, so the generation power of SRWPG micro resource is further increased. 3) In ultra low wind speed field, Z source network is introduced in power converter, Boost excitation can be realized, the current rate is increased and the output power can be added.2. Efficiency optimization and output power increase for solar power DC micro power supply based on bidden band width.In traditional model of PV, many parameters must be provided, such as the open circuit voltage, the short circuit current and the maximum power point voltage, the maximum power current. With the influence by the intensity of illumination and cloud,the model must be changed dynamically. To solve the disadvantage of photovoltaic generator DC micro power supply, a universal model based on the bidden band width is proposed, it can be suitable for different materials, different light intensity and different environment temperature. In some typical connection way, such as series connection,parallel connection and matrix connection, the output voltage and output power are analyzed. The MPPT independent control with incremental conductance method by variable step perturbation is put forward, the maximum total power output of PV array can be got, so the conversion efficiency can be increased. A new control strategy is proposed by combining the particle swarm optimization with variable step perturbation incremental conductance method of observation. Local power points may be produced to start the particle swarm algorithm, which makes the voltage of photovoltaic array work within the maximum power point in the neighborhood. Through the perturbation step size adaptive fast track the maximum power point, the photoelectric conversion efficiency can be further improved, and the optimization of energy efficiency of solar PV DC micro power supply can be realized.3. Layered coordination control strategy based on DC bus voltage variation and power management in building DC microgrid.Instead of the traditional multi-single input converters, a new single inductance multi-inputs DC/DC converter is proposed in building DC microgrid. It allows many distributed new energy DC micro resources supply power to building load individually or simultaneously. Under continuous mode, the relationship of voltage and current is derived,and the equation for power balance has been analyzed, and the same to its intermittent mode. According to the principle based voltage second balance, the inductance and clamping capacitance is selected reasonably. Then active clamp soft switch technology is developed to realize zero voltage commutation in multi-inputs flyback Buck-Boost converter, the switching loss can be reduced. According to layered coordination control strategy based on DC bus voltage variation to ensure the stable operation point under different mode, such as network free mode, network current-limiting mode, island mode,and disturbance mode, the control flexibility and reliability can be enhanced, the systemconsumption reduced, and make the building DC microgrid to have the function of “plug and play”.4. Consumption of renewable energy power in building DC microgrid and load optimal dispatch based on automatic demand response.Aiming at existing highly nonlinear, multiple constraints, high dimension feature about the problem of intelligent building electricity scheduling, DC microgrid building load optimal dispatch based on the price demand response is researched, comprehensive load regulations such as interrupt equipment, portable equipment, power generation equipment, charging equipment and energy storage equipment。It make multi-objective comprehensive optimization such as user dissatisfaction, user daily electricity, minimize electric power peak valley difference as a target, the problem of ADR is analyzed,building daily scheduling coding about electricity equipment and the model of building load optimal dispatch, and for non-linear production constraints in the model carry out linear transformation, DSCKMTOA(Double Structure Coding Kinetic Molecular Theory Optimization Algorithm) model of ADR problem has been built, and it has been solved with practical examples, the dynamic global optimization has been realized. Comparing the results of solve with other optimization method, such as BPSO(Binary Particle Swarm Optimization), BKMTOA(Binary Kinetic Molecular Theory Optimization Algorithm), DSCPSO(Dual Structure Coding Particle Swarm Optimization),DSCEA(Dual Structure coding Evolution Algorithm), DSCKMTOA has better electricity cost savings and load peak effect than others.