What is the common problem of photovoltaic off-grid system

Design photovoltaic off-grid system, flexible processing, not constrained by a fixed formula. Solar off-grid system can't solve the problem of all the electricity, met many rainy days in a row, can only save electricity. Off-grid inverter is no uniform standard, also not

in the design of solar off-grid system, should be flexible, not constrained by a fixed formula. Photovoltaic (pv) off-grid system can't solve the problem of all the electricity, electricity only when encountered in several consecutive rainy days. Off-grid inverter is no uniform standard, do not need compulsory certification. The good and bad products on the market is different, the quality of the product and the price also is very different. Buy off-grid inverter, fake and inferior products, should be timely alarm or complaints. 1. Design components, inverter and battery, they should match. No one should be too big or too small. In the design, the novice designers often computing power consumption is too large. For example, if the 1 p empty has been adjusted for running 12 hours, it is calculated as 10 KWH. If a 300 - watt refrigerator running 24 hours a day, it is calculated as 7. 2 degrees of electricity, leading to excessive battery capacity and high system cost. Design of battery capacity, it is best in two days. 2. The output of the photovoltaic off-grid system connected to the load. Each inverter phase and amplitude of the output voltage and current are different. Inverter does not support parallel output terminals. Do not connect the inverter output. 3. Elevator such as load cannot be directly connected to the output of the inverter, because when the elevator down, motor reversal and generate counter electromotive force, when entering the inverter damage the inverter. If you must use the off-grid system, it is suggested that between the inverter and the elevator motor add a frequency converter. 4. Complementary to the mains input of photovoltaic (pv) grid system, should be to do a good job of the insulation of the element. If the components of leakage current, it will be transferred to the mains, lead to public power leakage switch trip. 5. Components of voltage should match the battery voltage. Pulse width modulation controller for solar module through the electronic switch is connected to the battery. No sensors and other equipment. Component of the voltage is 1 battery voltage. 2. 0 times. If the battery is 24 v, parts of the input voltage is 30 - 50V。 One of the MPPT controller power switch tube and inductance and other circuits. Component of the voltage is 1 battery voltage. 3. 5 times. If the battery is 24 v, parts of the input voltage is 30 - 90V。 6. Components of the output should be similar to the power output of the controller. For example, 48 v30a power output of the controller should be 1440 volt ampere, the power of components shall be 1500 watts. Select the controller, the first to check the battery voltage, and then the component power divided by the battery voltage, the controller output current. 7. Battery charging current is commonly 0. 1 c - 0. 2 c, the biggest less than 0. 3c。 Lead-acid battery of 12 v200ah, for example, 20 a - charging current is in commonly Between 40 a, less than 60 a Max. The discharge current of the battery is commonly 0. 2C- 0. 5 c, the maximum of no more than 1 c, 12 v200ah lead-acid battery does not exceed the maximum output power of 2400 watts. Different manufacturers, different models and concrete numerical value is different also. In the design process to the manufacturers, please seek guidance.