The off-grid solar power system design is different from the grid-tie solar power system. The former needs to take into considerations many factors including the load, daily electricity quantity and 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. In order to ensure 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 mainly composes of the inverter selection, solar panel capacity, and batteries capacity.
The Maximum Power Point Tracking (MPPT) system is an electric system which can ensure the photovoltaic panel to output more electricity by adjusting the electric module’s working status. It can effectively store the DC emitted by the solar cell panel in the accumulator to effectively resolve the problem with the conventional grid that the domestic and industrial power use in remote areas and tourist destinations is not satisfied, while avoiding causing environmental pollution.
The solar charge controller regulates the charging and discharging of the battery, and controls the solar cell and the battery's power output to the load according to the power demand of the load, which is the core part of the whole photovoltaic power system. Now we will take the MPPT solar charge controller on inverter.com as an example to show how to properly connect the controller with the solar panel, battery and DC load.
The solar power system is used to convert the solar energy directly into the electric power via the solar cell module. The solar cell module is a solid device, which makes use of electronic characteristics of semiconductor materials to realize P-V conversion. In many areas without the power grid, the solar photovoltaic system can facilitate the lighting and domestic power supply for users. In some developed areas, it can be connected with the regional power grid to realize complementation. Then, how does the solar PV system work to generate the electricity used in our daily life?
In the solar photovoltaic system, the solar energy controller is used to coordinate the solar energy battery panel, accumulator, and load to ensure the whole solar photovoltaic system to function efficiently and safely. The solar streetlamp controller is the most central part in the whole solar streetlamp system. Therefore, to choose the quality solar street controller will influence the service life of the whole solar streetlamp system.
Our ATO-MPPT series of solar charge controller utilizes MPPT (maximum power point tracking) technology to extract the maximum power from the solar array to charge the batteries. The maximum power point tracking mode is full automatic and the user doesn't need adjustment. When the maximum power point of the array changes with ambient conditions, the charge controller automatically tracks the maximum power point of the array to ensure that the maximum energy of a day is obtained from the solar array.
In the solar off-grid system, the photovoltaic controller is to store the electricity generated by the photovoltaic module in the storage battery after transformation. In addition, it also has the functions of protecting the storage battery and preventing the battery from overcharging. At present, there are two main technical routes of the solar charge controller: Maximum power point tracking (MPPT) and pulse width modulation (PWM), both of which have its advantages and disadvantages, so users can select according to different scenarios.
For the current string power inverters, different manufacturers have different technical routes. Single-phase inverters of below 6 kW and three-phase inverters of below 10 kW generally use two MPPT loops. Each MPPT loop is equipped with one string. For the small industrial and commercial projects, power inverters of 20kW to 40kW are usually used. The number of MPPTs ranges from 2 to 4, and each MPPT loop is equipped with 2 to 4 strings. As to the large-scale power stations, high-power string inverters of 60kW to 80kW are generally selected. The number of MPPTs ranges from 1 to 6, and each MPPT loop is matched with 2 to 12 strings.
The solar energy charge controller is an automatic control device controlling the solar battery array to charge the battery and the battery supplies power to the solar inverter load in the photovoltaic power generation system. It can set the control conditions according to the charging and discharging characteristics of the battery, so as to control the power output of the solar energy battery component and battery to the load. Its main function is to protect the battery and stabilize the working state of the power station. The photovoltaic solar controller can be divided into a switch type controller, a pulse width modulation (PWM) type charge controller, a maximum power point tracing (MPPT) charge controller, and an intelligent controller according to functions and circuit structures.
