The Building Modular PV System And Its Control Strategy

Because of the increasingly serious energy problems, new energy, photovoltaic power generation system has become the focus of our attention. The building mounted photovoltaic experienced three generations of development, take full advantage of the building’s space, reduce the cost of photovoltaic power generation, and also improve the energy efficiency of buildings, and now become the main method of city photovoltaic power generation. Photovoltaic power generation also has its drawbacks, such as randomness, intermittent and dispersion. In order to solve these drawbacks, the paper analyzes the structure of the photovoltaic system, MPPT control, inhibiting power fluctuation control, limited control and energy storage control of PV system, building the control model of grid control model and off-grid modular control model of photovoltaic system.First, the development and construction of the building photovoltaic power generation system has been introduced. According to the power generation characteristics of the photovoltaic cell, the simulation model and analysis of the working characteristics of the photovoltaic cell has been established. By simulation and comparison of three different DC-DC converters, ultimately determine the most suitable converter for the building photovoltaic. Compare the speed of response of the different control method of maximum power point tracking control of photovoltaic systems and tracking results, the improved conductance incremental method can speed up the maximum power point tracking speed.Second, proposed a new control strategy of inhibiting the PV output power fluctuations, and established a control strategy and simulation. In the case of two different power fluctuations, compared the inhibiting power fluctuation control with the MPPT control, inhibiting power fluctuation control is better to determine the large power fluctuations, and suppress this fluctuation in a timely manner. So that the output power is more stable, and the power fluctuation can be reduced. Third, the building photovoltaic grid control strategy has been discussed and PV module model, DC-DC converter and the inverter simulation model has been established. Proposed a semi-autonomous control, so that in the case of limited run grid, each PV array can be constant power control, and the output power of PV system is able to meet the power demand of the grid.Finally, Proposed the integrated system, include modular PV control, isolated DC-DC converter, super capacitors and communication monitoring system, so that the output current of PV module can be stable; each PV module can achieve its maximum power point; solve the energy distribution under the conditions of partial shadow and PV module mismatch problems; and improve the overall performance of the system.