Introduction to wenshan solar street light system in off-grid photovoltaic power generation systems

Off-grid photovoltaic power generation system is mainly composed of solar photovoltaic power generation device, storage, storage device, controller, inverter. In the face of the parts were briefly introduced. Solar photovoltaic power generation device can be made of monocrystalline silicon or polycrystalline silicon and amorphous silicon photovoltaic devices. With bo

off-grid photovoltaic power generation system is mainly composed of solar photovoltaic power generation device, storage device, controller and inverter. The following is for each part are briefly introduced. Photovoltaic solar power generator can be made of monocrystalline silicon or polycrystalline silicon and amorphous silicon photovoltaic devices. A set of glass and special material for solar cells is known as the solar energy battery components. Multiple solar battery components are connected to form a solar array. Type and composition of the solar cell is based on the system needs to select the power, running environment and cost. Energy storage device for photovoltaic directly affected by weather conditions, so it is intermittent and unstable. In order to maintain the system must be continuous power supply capacity, energy storage device must be provided to store some electricity, and provide electricity without sunshine. At present, photovoltaic power generation system mainly use the battery energy storage. Commonly used batteries including lead-acid batteries, nickel-cadmium batteries, lithium ion battery, etc. Lead-acid battery: monomer battery voltage is 2 v, 500 - cycle life 1500 times a nickel cadmium battery: 1 single battery voltage. 0 - 1. 3 v, cycle life 2500 lithium ion battery, 3 single battery voltage. 7 v) , 1000 - cycle life 10000 times a nickel cadmium battery and lithium ion battery is expensive, but large capacity per unit volume. They are mainly used for small volume and large capacity of occasions, such as mobile phones, cameras, portable computers, and other digital products. Usually, the sealed lead-acid battery is mainly used for off-grid pv system. Lead-acid batteries are very cheap, sealed lead-acid battery maintenance free, easy to use. Battery is the most important parameters of voltage, capacity and cycle life. The unit of voltage is the unit of volt, capacity is ampere hour, circle life is the number of charging and discharging. Controller battery to charge and discharge to have certain requirements. Frequent to over charge and discharge can reduce the service life of batteries. Must be conducted for battery charging and discharging control, this is the main function of the controller. Maximum power point of solar cell is based on the user's power, storage battery charging and discharging and solar cell light conditions to choose, coordinated charge and electric current. Controller and detection, protection and display system. Mainly adopts DC - controller The DC conversion circuit to convert the voltage and current. See the DC - The DC conversion principle. DC - DC converter principle; Part of it. Inverter converts dc to ac equipment mainly adopts SPWM full bridge inverter circuit to generate sine wave alternating current. See the principle of SPWM inverter. Inverter principle; Part of it. Power load using a direct current or alternating current (ac) electrical equipment. Simple solar photovoltaic power generation device without inverter, output dc, only some of which can output different dc voltage, its composition is shown in figure 2. Controller can receive solar panels output dc and control battery charge or discharge current. A simple controller directly to the battery to the output side, the system output voltage is equal to the battery voltage. Some controller have DC conversion circuit, can output several different DC voltage, such as 5 v, 9 v, 12 v, etc. , suitable for different electrical appliances. The output power of the system is usually small, mostly using portable structure.