Control the rural wholesale solar street lamps in the photovoltaic power station

Controller is an important part of photovoltaic power station, and then to the controller, model selection of the design must consider the can controller for photovoltaic power station of power transformation and optimize the battery charging control and management. Only select the appropriate type, can lift the



the controller is photovoltaic power station 【 Photovoltaic power station, is a use of solar energy panels, the use of special materials such as silicon, composed of electronic components such as inverter power generation system, connected to the grid and sending electricity to the grid photovoltaic power generation systems. 】 An important part of, and then to the controller, model selection of the design must consider the can controller for photovoltaic power station of power transformation and optimize the battery charging control and management. Only select the appropriate type, can improve the safety and reliability of the photovoltaic power station, to provide users with better power quality. Stand-alone photovoltaic power station by photovoltaic cells usually 【 Solar photovoltaic cells ( Photovoltaic cells) For the sun's light energy into electrical energy directly. 】 Array, battery Battery is a kind of independent and reliable power supply, it is not affected by the ac power, when any accidents which happen in power plant or transformer substation, even in the whole factory, total station under the condition of the ac power is power outage, still can guarantee the dc electrical equipment in the system is reliable and continuous, smooth and voltage; At the same time also can be used as a factory, total station, emergency lighting power supply, uninterrupted power supply is the last barrier. 】 , controller, inverter, Inverter is the direct current (dc) can ( Batteries, battery) Converted into alternating current (ac) ( General is 220 v, 50 hz sine wave) 。 】 , low voltage transmission lines and the user load. The battery plays a storage box to adjust the action of electricity: when sufficient sunshine photovoltaic cells produce excess energy, will spare battery energy storage; When the system capacity is insufficient or load power consumption, battery to load supplement energy, and keep the stability of the power supply voltage. Controller is control part of photovoltaic power station: it according to the intensity of sunlight and the change of the load, continuously to switch the working state of the battery and adjustment, in the recharge and discharge or run alternately floating charge, and other conditions, so as to ensure the continuity and stability of photovoltaic power station work; By testing the battery charged state 【 Battery use after a period of time or long on the residual capacity with the fully charged state capacity ratio, often expressed as percentage. 】 , a battery charging, stop charging, continue to discharge, reduce discharge or stop discharge instructions, to protect the battery from over charging and discharging; In addition, the controller also has a variety of protecting and monitoring functions, the controller is the center of the power supply, its operation conditions directly affect the reliability of the whole plant, is the system design, production and installation in the process of a key part of the need to pay special attention to. Controller to control the basic principle of charge and discharge, battery has different charging and discharging characteristics of different, so also should have different control strategy. Here in lead-acid batteries, for example to illustrate the working principle of the controller. There are many kinds of lead-acid battery charging ways, such as batteries, current limiting constant voltage charging, increasing voltage charging, etc. Which is the most used current limiting constant voltage charging. The charging process is divided into three' For the three, is the Japanese novelist, light fiction writer. 】 Phases. The first stage, the active substance formed in the pores of sulfate surge, too late to spread outside the plate, so the battery voltage, voltage of the battery to rise faster ( OA section) ; The second stage, with the increase of active substances in the microporous sulfuric acid proportion speed and the speed of spread out gradually tend to balance, so the voltage of the battery up slowly, AB section) ; The third stage, the current makes the water in a large number of decomposition, battery on the two plate began to produce large amounts of gas, the gas is a poor conductor and the ability to make the battery internal resistance increases, voltage of the battery continue to rise but rising significantly slower speed ( CD) 。 After the third stage, if continue to battery, will be damaged due to overcharge, affect the service life of the battery. According to this principle, in the controller set voltage measurement and voltage comparison circuit, voltage monitoring based on point D, can judge the battery charged should end; This control mode is voltage type charging control, voltage comparator set point D is called the 'threshold voltage or voltage threshold. '