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1.According to the load type and power of the user to confirm the power of the solar off grid inverter, the household load is generally divided into inductive load and resistance load. The load of the washing machine, air conditioner, refrigerator, pump, smoke pump and so on is inductive load, and the starting power of the motor is 5-7 times of the rated power. When calculating the power of the inverter, the starting power of these loads should be taken into account. The output power of the inverter is greater than that of the load. For monitoring stations, telecom stations and other stringent requirements, the output power is based on the sum of the load power. But for poor families in general, considering that all the loads can not be opened at the same time, in order to save cost, the sum of the load power can be multiplied by the coefficient of 0.7-0.9.

2.Confirm component power according to user’s daily power consumption. The design principle of the component is to meet the daily demand for the load per day under the average weather conditions, that is to say, the annual power generation of the solar cell component is equal to the full year load of the load. Because the weather conditions maybe below or above the average, the solar cell components are basically designed to meet the needs of the worst season of light, that is, in the worst season, the battery can also be basically full of electricity every day. But in some areas, the worst season illumination is far below the annual average. If the power of the solar cell component is designed in the worst case, the power generation at other times of the year will be far more than the actual demand, causing waste. At this time, we can only consider increasing the design capacity of the battery and the storage of electric energy, make the battery in the shallow discharge state, make up the damage caused by the shortage of electricity generation in the worst season. The power generation capacity of the component can not be completely converted into electricity. The efficiency of the controller and the loss of the machine and the loss of the battery are also considered. The solar controller has two types of PWM and MPPT. The efficiency of the PWM controller is about 85%, the input voltage range is narrow, but the price is low, the efficiency of the MPPT controller is about 95%, and the price is higher. In the course of charging and discharging, the battery also has 10-15% loss.

3.The battery capacity is determined according to the user’s night power consumption or expected waiting time. The task of battery is to ensure the normal load of system load when the amount of solar radiation is insufficient. For important loads, it is necessary to ensure the normal operation of the system within a few days, and consider the continuous rainy days. For general loads such as solar street lamps, it can be selected within 2~3 days according to experience or need. Important loads such as communication, navigation, hospital treatment and so on are selected within 3~7 days. In addition, the installation location of the photovoltaic power system should be considered. If it is in a remote place, the capacity of the battery should be larger, because the maintenance personnel will take a long time to arrive at the scene. In practical application, some mobile communication base stations are not convenient to go to a high mountain high road. In addition to the normal battery group, it is also equipped with a set of reserve battery. For the poor families, the price is mainly considered, and the rainy days are not considered, and when the sun is good. When the sun is not good, use it less. When choosing a load, try to use energy-efficient devices such as LED lights and variable frequency air conditioners. The design of storage battery mainly includes the design and calculation of battery capacity and the design of series and parallel connection of battery pack. Most of the photovoltaic power generation systems are lead-acid batteries. Taking into account the life of batteries, the average discharge depth is 0.5-0.7.

SSP3118C off grid solar inverter specifications 1-5KVA

1. Pure sine wave inverter
2. Cold start function
3. Remote panel available
4. Auto restart while AC is recovering
5. Overload and short circuit protection
6. Compatible to mains voltage or generator power
7. Selectable charging current based on applications
8. Configurable AC/Solar input priority via LCD setting
9. Built-in MPPT/PWM (Optional) solar charge controller
10. Smart battery charger design for optimized battery performance
11. Parallel operation with up to 6 units only available for 4KVA/5KVA
12. Selectable input voltage range for home appliances and personal computers

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The main points of dust proof and waterproof design for outdoor cabinet: mainly for three places to carry out sealing treatment, so that the environment and the outside environment in a certain degree of isolation, to achieve the final design purpose. First of all, there are good dustproof measures for the cabinet to ensure the normal operation of the equipment. We begin with the seams of the cabinet, the joint part, the line interface, the design of the air duct and the fastening parts of the fasteners, because the dust and water in various environments enter the cabinet by these ways.

Main points of dust proof and waterproof design of cabinet
1.Air inlet and outlet: using maze structure and dustproof net to achieve dustproof and waterproof purposes.
2.The gap between the air duct joint: install the sealing strip or apply the sealant to achieve the purpose of protection.
3.Cabinet door: install sealing strip (EPDM) to achieve the purpose of dustproof and waterproof.
4.Lock installation: lockset customization protects rubber part and applies sealant.
5.Cable access: cable terminals, PG terminals, flanges, fireproof mud, etc.

People often install the filter network device inside the outdoor cabinet, which includes a flat connection bar and sticker glue on the other plane of the connecting bar to make it better to protect the dust and waterproof, ensure the interior cleaning of the cabinet and the good operation of the equipment.

IP55 Protection Outdoor Telecom Cabinet

■.Highly integrated outdoor electrical enclosure with strong housing ability, can be used as equipment cabinet, battery cabinet or integrated cabinet
■.Well environmental adaptability with IP55 class protection and full ranges of temperature control system
■.Precise and separate temperature control reduces energy cost
■.Multi-layer panel structure makes less heat absorbance and saves energy
■.Anti-theft design and earthquake protection tests ensure outdoor electrical enclosure and equipments safety
■. Well environmental adaptability with IP55 class protection
■.Support delivery in whole or in parts with no limits to installation scenario

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1.Natural heat dissipation
The cooling method of natural heat dissipation of solar inverter refers to the purpose of realizing the temperature control of the local heating device to the surrounding environment without using any external auxiliary energy. It usually includes three main heat transfer modes, heat conduction, convection and radiation, in which the convection is dominated by natural convection. Natural heat dissipation or cooling is often applied to low power devices and components with low temperature control and heat flow density, and sealed or densely packed devices are not suitable for other cooling technologies. At present, the single-phase inverter and the three-phase inverter under 30kW, most of the manufacturers can achieve natural heat dissipation, and a few three phase inverters of 100kW can also achieve natural heat dissipation.

2.Forced heat dissipation
The cooling method of forced cooling is mainly by means of fans and other forced devices around the air flow, thereby removing the heat emitted from the device. This method is a simple and effective heat dissipation method. If the space between components is suitable for air flow or suitable for installation of local radiator, this cooling method can be used as much as possible. The method of enhancing the forced convection heat transfer capacity increases the heat dissipation area and produces a relatively large forced convection heat transfer coefficient on the cooling surface. Increasing the heat dissipation area of the radiator surface to enhance the heat dissipation of electronic components has been widely applied in practical engineering. In engineering, the fin is used to expand the heat dissipation area of the radiator surface to achieve the purpose of enhancing heat transfer. The choice of radiator material is directly related to its heat dissipation performance. At present, the material of the radiator is mainly made of copper or aluminum, and the expanded heat exchange surface is made by folding fins / punching thin fins.

3.Comparison of two kinds of heat dissipation methods
Natural heat dissipation has no fans, low noise, but slow heat dissipation, and is generally used for small power inverters. Forced air cooling need to configure the fan, large noise, but fast heat dissipation, generally used in high-power inverters, in the middle power of the series of inverters, use both way. Through the comparison experiment of the heat dissipation capacity of the group series inverter, it is found that the group series inverter with 50kW power level using forced heat dissipation is better than the natural cooling method. The temperature rise of the key components, such as the capacitor and IGBT in the inverter, can be reduced by about 20℃, which can ensure the long life and high efficiency of the inverter. However, the temperature of the inverter with natural cooling mode increases and the life of the components decreases. Forced air cooling also has two kinds of high speed fans and medium speed fans. The use of high speed fans can reduce the volume and weight of the radiator, but it will increase the noise and the fan life is short. If the medium speed fan is used, the radiator is slightly larger. But when the power is low, the fan does not turn, and the fan runs at a low speed in the middle power. In fact, the full power operation time of the inverter is not much, so the fan’s life can be long.

REVO-E 3-5kW Hybrid Solar Energy Storage Inverters

1. PV and utility power take the load at same time ( can setting ).
2. Output power factor PF=1.0
3. On/Off grid with energy storage.
4. AC charging and AC output time setting.
5. Charging voltage and charging current timing.
6. External Wi-Fi device optional.
7. Connected with battery optional.
8. Wide PV input range 120-450VDC.
9. MAX PV Array Power 4500W.

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High temperature is the main factor that causes the most likely failure of electronic devices including UPS. At high temperature, the leakage current of the device increases and the voltage decreases. According to Arrhenius’ law, when the ambient temperature is 25 degrees centigrade, the life of components or equipment is reduced by half at 10 degrees centigrade. When the temperature rises according to the arithmetic gradient of 10 degrees, the life of components or equipment will decrease which follow 1/ (n=1, 2, 3…) the law of geometric progression. And the temperature rise inside the machine comes from the power consumption of every circuit in the machine. Transformer is one of them. If there is no transformer, the power consumption can be reduced. So in this sense, because of the existence of transformer, to a certain extent, the reliability of the system is reduced.

The mistake here is to confuse the mechanical stability and electrical performance of transformers. The stability here refers to the stability of the electrical properties. Since the existence of transformers reduces the reliability of the system, of course, it also reduces the stability. People in misunderstandings mistakenly regard the stability of electricity as mechanical stability: the weight of the transformer is large and the center of gravity is stable, so the reliability and stability of the system are guaranteed. Furthermore, the transformer is only a part of the UPS. It does not add trouble to the whole and improves the reliability of the device. If you look at the problem from this point of view, it can be said by any part of the device.

GP9111C 6-15KVA GP9311C 10-40KVA Low Frequency Online UPS

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Under normal operation, high frequency switching power supply equipment has little maintenance workload, mainly dustproof and regular dedusting. Especially in the area where the climate is dry, the dust in the air is more and the dust will be deposited in the machine. When the air is wet, the host control disorder will cause the main engine to be disturbed and the inaccurate alarm will occur. A large amount of dust also causes poor heat dissipation in the device. Generally, every quarter should be thoroughly cleaned. The second is to check whether the connectors and plugging parts are loose or unfastened during the dust removal.

Because rectifier can not eliminate instantaneous pulse interference, there is still interference pulse after rectification. In addition to the function of storing DC power, the equivalent capacitance of the battery is directly proportional to the capacity of the storage battery. Therefore, maintenance of battery work is very important, although the battery pack is used to maintain the battery, but this is only to eliminate the previous measurement, ratio, time to add distilled water. But the influence of the working state on the battery has not changed, the effect of the abnormal working state on the battery has not changed, so the work of the battery is all in the state of floating charge, and at least one discharge should be carried out every year in this case. Before discharging, the battery pack should be recharged evenly to achieve a balanced battery pack. During discharge, if one reaches the discharge termination voltage, the discharge should be stopped. The check discharge is not a percentage of the discharge capacity, but is concerned with the discovery and treatment of backward batteries, and then do the check discharge experiment after the treatment of the backward cells. This prevents accidents, so as to avoid the deterioration of backward cells in the discharge to reverse polarity batteries. At least 8 batteries for each battery should be used as the indicator battery. As a reference to understand the working conditions of the whole battery, the battery should be measured and recorded regularly.

Items that need to be checked regularly in daily maintenance are:
Clean and detect the voltage and temperature at both ends of the battery;
There is no loosening corrosion at the connection point, and the pressure drop of the connecting strip is detected;
Battery appearance is intact, there is no shell deformation and leakage;
Whether the acid mist escapes from the pole and the safety valve;
Whether the host equipment is normal and so on;
The maintenance free battery should be operated, daily managed carefully standardized, so as to ensure the equipment to maintain good operation condition and prolong the service life;
Ensure that the DC bus maintains qualified voltage and battery discharge capacity;
Ensure the operation of the battery and the safety of the personnel.

This is the purpose of battery maintenance, as well as the contents and operation rules of battery operation rules. When reverse voltage, large voltage drop, large differential pressure and acid fog leaks were found in the battery pack, the corresponding methods should be adopted in time to restore and repair, and replace batteries that can not be recovered need to be replaced. However, batteries with different capacities, performance and manufacturers can not be connected, otherwise they may have adverse effects on the whole battery. The battery pack whose life time has expired should be replaced in time, so as not to affect the power supply system and equipment mainframe.

When the power system fails, the cause should be identified first, whether it is load or power supply, whether it is a mainframe or a battery pack. Although the switch power system has the function of fault self inspection, it is very convenient to replace the parts, but it is still necessary to do a lot of analysis and inspection to repair the fault. In addition, if the self checking part fails, the contents of the display may be mistaken.

When the main machine is broken down or destroyed, it is necessary to find out the cause and remove the fault before restarting. Otherwise, the same failure will occur. The good equipment also has a life span, and there will be various kinds of failures, but the maintenance work is good to prolong life and reduce the occurrence of failure. Do not ignore the maintenance work because of high intelligence and maintenance. Prevention is an important guarantee for safe operation at any time.

SHW48200 48VDC Outdoor Power Supply MPPT Off-Grid Telecom Station Solar Hybrid System

■Adopt advanced MCU microprocessor control technology.
■Advanced MPPT Technology,High converting efficiency higher than 97% for minimizing energy loss.
■Reversed current protection at night, over voltage and reverse polarity protection.
■Capable of selecting different charging mode for various types of batteries.
■Protection degree:IP55
■Industy-leading power density compact size and high reliability;
■Doorframe designed with waterproof structure, posted on the seal and equipped with waterproof lock on the door double insulation design;
■Cabine adopt quality galvanized sheet or aluminum coated steel sheet as material, surface coating anti-UV power;
■Suitable for outdoor installation.

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