solar inverter

Today we see many solar plants connected to the power grid, and there will be more and more in near future. All experienced power system engineers, and operators see that it is a must for these solar plants to have sophisticated control system to achieve coordination and integrity between them and other traditional power plants exist in the grid. This smart control system can be done only through solar inverters which represent the brain of the solar power plant.

Today, the new frontier of solar inverters become exist everywhere, it's the smart solar inverter which has the ability to interact with the power grid. It has internal advanced software that enable performing amazing actions. The smart solar inverter is able to connect with the grid even with the presence of disturbances like voltage changes, the inverter automatically switches from operating mode to standby mode, then operating mode or even turn off if the disturbances last for long time.

What is the on-grid inverter data sheet? It's a sheet shows the on-grid inverter specs, so can judge if the inverter can be used in our system or not. It's an important matter to be able to read the sheet and understand it before buying the on grid inverter.

It's a solar system that is connected and synchronized with the power grid. So, the electrical load will be fed from both sources which share to each other in feeding it. In cloudy days or at night where the solar system generation is low or even is not exist, the electrical load takes its power requirements from the power grid. And in sunny days where solar generation exceeds load power requirement, the load take all its power requirement form the solar system and surplus solar generated electricity will go to the power grid to be used elsewhere.

Today we will introduce a home solar power system design below 10kW, which is installed on the roof of the house and connected to the grid of 220V or 380V. The maximum installation capacity is 25% of the capacity of the upper-level transformer. First of all, it is required to determine whether the load capacity of the roof can meet the requirements. The loading requirements of the solar power system equipment for the roof are greater than 30kg/m2.

With the constantly advance of industrial and commercial photovoltaics, there are less and less large-scale, flat, facing, unshielded cement or colored steel roofs, and the rest may be multi-angle, multi-oriented, sheltered, multi-structural roofs. How to design solar panel system on the complex roofs? The most concerned issue for designers and investors is to control the cost, ensure the power generation, and be safe and reliable.

The solar PV system is not only environmentally friendly, but also saves money and makes money, becoming a best choice of alternative or backup power source for many families. However, it need proper maintenance, so as to ensure the generating capacity of the system, and guarantee the service life. Do you want a better power generating efficiency and a longer service life of your home solar power system? It should be guaranteed by the sound maintenance.

If you plan to design and install a grid tie solar PV system for your home, you will want to know how much electricity the system can produce each year. Now we will take the roof of 60m2 as an example to make this calculation. At present, the household solar power system generally adopts the monocrystalline silicon solar panel and polycrystalline silicon solar panel. Its specification is generalized as 36V 280W, and the single piece of solar panel generally has an area of 1.8 m2...

The solar PV system is constituted by the solar cell, storage battery pack, charge controller, inverter, AC power distribution cabinet, lightning protection system, combiner box, DC power distribution cabinet, environmental monitoring system, monitoring system and other devices. The following is the overview of the main components of a solar PV system.

The light storage system includes solar energy components, controllers, solar inverters, batteries, loads and other equipment. At present, there are many technical routes, but the energy needs to be gathered on a certain point. At present, there are mainly two kinds of topological structures: DC coupling and AC coupling.

Leakage current of the photovoltaic system, which is also known as the square matrix residual current, is essentially a kind of common mode current. The cause is that there is parasitic capacitance between the photovoltaic system and the earth. When the parasitic capacitance-photovoltaic system-grid forms a loop, the common mode voltage will produce the common mode current on the parasitic capacitance. When the photovoltaic system is equipped with a industrial frequency transformer, because of the relatively high parasitic capacitance between the transformer windings in the loop, the common mode current generated by the common mode voltage in the loop can be suppressed to a certain extent. However, in a photovoltaic system with no transformer, the loop impedance is relatively low, and the common mode voltage will form a large common mode current, ie, leakage current, on the parasitic capacitance between the photovoltaic system and the earth.

Most of the PV inverters on the present market are generally in the IP65 protection level, with a certain degree of wind, dust and water resistance. However, in the summer, the ambient temperature is high, and various components in the inverter are prone to high temperatures during operation, resulting in a decrease in power generation efficiency and even affecting the service life of the components. Therefore, the inverter in some photovoltaic systems is installed with a sunshade to reduce the temperature of the equipment. In addition, the installation environment of the inverter should be well shaded and ventilated to ensure the convection of the air and also increase the power generation capacity of the power station

The energy flow path of the solar PV system usually contains a solar panel, a combiner box, a DC power distribution cabinet, a grid-tie inverter, an AC power distribution cabinet, and the connection cables. Based on the energy flow of the PV system, it is necessary to fully consider some important factors affecting the conversion efficiency in the design of the solar power system.

The installation scheme of common ground distributed projects is to install near a string of components at the closest. It adopts the fixed-rack installation or hoop-type installation to directly fix the equipment on the stand column. If this kind of scheme is used, it is required to pay attention to the strength of the rack and column, as well as the height of the solar PV inverter over ground, avoiding being submerged in stormy days because of being placed at a too low height.

The PV module capacity and solar inverter capacity ratio are commonly referred to as capacity ratio. Reasonable capacity ratio design needs to be considered comprehensively in the light of the specific project. The main influencing factors include irradiance, system loss, inverter efficiency, inverter life, inverter voltage range, assembly installation angle and so on. Because the inverter accounts for only about 5% of the system cost, the number or power of the inverter is reduced by the overmatching of the components in the distributed photovoltaic power station system, and the investment income is very small, which also bring other problems, the specific analysis is as follows.

Input overvoltage protection: When the DC-side input voltage is higher than the maximum allowable DC array access voltage of the grid tie inverter, the inverter is not allowed to start or stop within 0.1s (in operation) and a warning signal is released at the same time. After the DC-side voltage is restored to the allowable working range of the inverter, the inverter should be started and operated normally.

The micro-inverter technology directly combines the inverter with a single photovoltaic module to equip every photovoltaic module with an inverter module which is capable of DC-AC conversion and the MPP tracking. The inverter module can directly convert the power generated by the photovoltaic module into the AC for the AC load use or transmit it to the grid.

Charging controller, check the voltage setting of the rectifier and check the voltmeter to have normal indication. If the battery temperature is below 55°F (about 12.778°C), charging to a higher voltage (at least 14.8 volts for a 12 volt system) should be allowed. If your charge controller has the temperature compensation function, it will automatically adjust. If there is an external temperature sensor, please make sure that it has been attached to the battery. If there is no automatic adjustment function, it is required to manually increase the voltage and adjust back in the spring (adjust to 14.3 volts). If the charge controller is not adjustable, try to keep the battery in a warmer environment.

As one of the multiple development and utilization approaches of solar energy, solar photovoltaic power generation has the characteristics of pollution-free, renewable, flexible and storable and so on. The photovoltaic power generation system has been put into practical use in the fields of road lighting and residential construction. The water treatment industry is also suitable for the application of the photovoltaic power generation system because of its unique industry characteristics. The solar photovoltaic system is composed of a solar battery pack, a solar charge controller, and a battery.

The application of the photovoltaic power generation system has the following advantages in the wastewater treatment industry:

No sheltering of tall buildings around

Most of the water treatment plants are located in areas with relatively concentrated industrial enterprises and remote positions. The surrounding buildings are mostly low-rise buildings such as industrial plants, and there is less shielding for the photovoltaic power generation system in water treatment plants. At the same time, since the construction condition of the water treatment plant itself, the structure and the building unit itself are low in height and sparse in layout, and are not easy to cause occlusion, thus having better illumination conditions.

Rather big installable roof area

Due to the need of the technological procedure, most water treatment plants have rather big architectures, such as biological reaction tanks, secondary sedimentation tanks, blower rooms and so on, which usually have large installation spaces for photovoltaic systems above. In addition, the photovoltaic power generation system of the water treatment plant mostly belongs to the roof-type distributed photovoltaic system, thus involving no newly increased land, changing no land application, affecting no cultural relic protection requirement, increasing no building area and changing no building structure.

Improve the technological treatment effect

The reasonable layout and design of the photovoltaic power generation system of the water treatment plant can reduce the evaporation amount of the pool water, increase the water treatment capacity, reduce the impact of sewage evaporation on the environment. At the same time, it can still reduce the wind speed above the pool, improve the local small environment, increase the temperature of the pool water, enhance the growth activity of the microorganisms, improve the sewage treatment effect, and finally achieve the purpose of improving the water treatment capacity and the comprehensive economic benefits of the project.

High and stable power generation of the water treatment plant

The loads of water treatment plant include high-power loads such as blowers and submersible pumps, as well as low-power loads such as gates, grilles, and submersible flowers, which usually have higher computational powers. Moreover, due to the relatively balanced water volume, the operation of each technological equipment is relatively stable, and the load characteristics are stable, thus being convenient for the design of the solar photovoltaic power generation system.

Since the water treatment plant has great power consumption and small changes, the reasonable design of the photovoltaic system can fully utilize the photovoltaic power, avoid power waste of the solar inverter, and reduce the light rejection rate.

Good financing conditions

Water treatment plants usually have long operating cycles, guaranteed operations, stable benefits, high self-sufficiency ratio, and high return on investment, thus avoiding the problem of financing difficulties.

Low maintenance cost

After the establishment of the solar photovoltaic system, its operating costs, in addition to equipment damage caused by force majeure, are mainly the cleaning water expense and other maintenance costs. The cleanliness of the effluent or recycled water of the sewage treatment plant can meet the cleaning needs of the PV modules. At the same time, the water source after cleaning can be directly collected into the sewage treatment process, thus saving water and reducing maintenance costs.

The off-grid solar power system design is different from the grid-tie solar power system. The former needs to take into consideration many factors including the load, daily electricity quantity local climate conditions, and so on, to choose different design plans according to clients’ practical demands. Therefore, the off-grid solar photovoltaic system is comparatively complex. To ensure the reliability of the off-grid PV system, a thorough survey of customer demands is very necessary. The design of an off-grid solar power system is mainly composed of the inverter selection, solar panel capacity, and battery capacity.