Research On Emergency Power System Based On Renewable Energy

In this paper, the system as the research object, which is the emergency power system based on renewable energy. It includes photovoltaic power, wind power, switching means,inverters, energy storage devices, detection and controller, monitoring system, etc. And by means of feature analysis and modeling simulation, focusing on the control system was studied, aimed at improving emergency power system reliability, and maximum use of renewable energy. The main contents are as follows:The first, based on the composition structure of a conventional emergency power systems, then combined photovoltaic and wind power module power module itself operating characteristics, designed the structure of the emergency power system based on renewable energy, and which has the characteristics of renewable energy power module and power grid coordinate for energy and hierarchical load.The second, for the photovoltaic power modules, we designed an improved MPPT algorithm to resolve the problem; it is when emergency power is working under complicated illumination conditions, the maximum power point of the system maybe to stay in the second advantage, causing the system output power to reducing. In this paper,with DMPPT circuit structure of photovoltaic array as the research basis, through the study of photovoltaic cell module output characteristic curves, came to the conclusion that the PV module output equivalent characteristic curves have three sections, and can be obtained directly through the three measured parameters, which are IM, UM, and Udc max. Again through the equivalent characteristic curves of photovoltaic module, after classification discussion and formula derivation, to obtain the best working voltage estimate formula of the PV array, when two series-connected photovoltaic module work under different light conditions. Then can be the estimated value as the maximum power voltage reference value, combined with the traditional P&O method to obtain the improved MPPT algorithm,and through modeling and simulation, the improved MPPT algorithm was validated.The third, for the wind power module, we designed a wind control strategy based on prevention twisted cable, and it can reduce the probability of torsion cable for wind generator when in the work process of the emergency power, to saving time of its downtime, untwisting and re-start will required to spend, thereby it can be increasing the total generating capacity of the emergency power system. The wind control strategy based on the prevention of twisted cables is designed in this paper, specifically, in the yaw anglerange of it is there a possibility of occur twisted cables, the budget for the shortest path on the point of whether it will happen after twisting as the judgment condition, to choose whether to perform preventive twisted cable direction.In addition, this paper also studied the pitch control and yaw control system untwisting control system of the wind power module, in order to better application of wind power. And the associated simulation model are established,to verify the proposed control strategies.The fourth, for the energy management and control system of the emergency power, a coordinated power supply control strategy is designed, which makes the emergency power system as safe, reliable and efficient as possible. The power coordinated control strategy of emergency power is designed in this paper, with clean energy and emergency load preference, as well as maximizing the reliability of power supply and so on. Specifically,when the emergency power storage device is sufficient,through the switch to make that the new energy power module will take precedence over the mains supply energy to the user;And in case of emergency, the processing of hierarchical load and the application of solar hybrid will increase the emergency power supply time.The fifth, monitoring system is designed, to facilitate the realization of human-computer interaction, and increase the flexibility of simulation model application.In this paper, completion of these monitor interfaces design, it is including the photovoltaic power modules, the wind power module and the energy management and control system of the emergency power. And the monitor interfaces are debugged, to realize the monitoring of the emergency power supply system.