Home

In the solar power generation system, it is mainly composed of PV module, storage battery, solar controller and load. Although the cost of solar energy controller is only a small part of the PV system, the choice of the controller can optimize the system to a large extent.At present, the popular solar controller on the market is mainly ordinary solar controller, PWM solar controller and MPPT solar controller. Ordinary solar controller is the first generation technology, due to the factors of the internal resistance of battery, it is difficult to charge batteries fully, and solar panels is not fully utilized, the MPPT tracking efficiency is only 70%-76%, so it has been out of the market. PWM solar controller is the most popular used, solar MPPT controller is nowadays trend, so more and more people in the industry have to make a choice between PWM solar controller and MPPT solar controller.

PWM solar controller is the second generation technology, it use the PWM control mode, compared with ordinary solar controller, has been improved a lot. Pulse width modulation (PWM) is an effective technique to control analog circuits by digital output. In the PWM solar controller, the battery pack is not only the storage of the electric energy, but also the voltage regulator of the solar system. Real time monitoring of battery potential by controller, and the number of potential solar access control or cut out of the sub matrix (or duty cycle rate), so as to adjust the charging current charge into the battery, in order to control the battery potential; The load obtains a relatively stable voltage from both ends of the battery pack. PWM solar controller can solve the problem of battery dissatisfaction, MPPT tracking efficiency of 75 ~ 80%, but the solar panels are still not fully utilized.

Solar MPPT charge controller is the third generation technology, is now the most high-end solar controller, the current use is relatively little, but very hot in the industry. MPPT solar controller, referring to the “maximum power point tracking” function, is the upgrading of PWM solar controller. The MPPT solar controller can detect the voltage and current of the solar panel in real time, and continuously track the maximum power (P=U*I), so that the system can always charge the battery with the maximum power. The tracking efficiency of MPPT is 99%, and the efficiency of the whole system is up to 97%, and the battery charging phase can be divided into MPPT charging, constant voltage equalizing charging and constant voltage floating charging.

In theory, the efficiency of the solar power generation system using MPPT controller will be 50% higher than the efficiency of solar controller using traditional one, but in the test, there is the impact of the surrounding environment and a variety of energy loss, though the efficiency did not reach the theoretical value, but also can improve 20%-30%. As the promotion of photovoltaic technology , coupled with energy saving and cost saving concept, I believe there will be more and more people in the industry tend to MPPT solar controller.

Power supply and distribution system as an important part of the information system, the basic requirement is that the system must be able to work continuously. In order to achieve the purpose of continuous work, the first is that the system should have high reliability, and secondly the system must be able to quickly repair. If it can not be repaired quickly , you may face second failures leading to the risk of paralysis of the entire system, can not guarantee the load continuous work.

In terms of rapid repair, modular UPS has a natural advantage. First of all, in the repair time, due to the characteristics of quick plug, modular UPS can complete the replacement at the scene, the average repair time in half an hour, compared to the traditional tower UPS for repair time of 24 hours, the repair speed improved significantly. Secondly, in the repair quality, repair the modular uninterruptible power supply through the fault module replacement, while the traditional tower UPS need factory to send professional engineers to the locale to locate the fault and repair the fault circuit board and disassemble, the repair cycle is long, and exist the process of communication and positioning, easily lead to repetitive work, affecting the efficiency of fault handling.

Some users may doubt that the N+1 structure of modular UPS is not as stable as the 1+1 system. Indeed, theoretically, the reliability of the 1+1 system must be the highest in the N+1 systems. But factly it is often not so simple:

First of all, this conclusion ignores the load rate, as 1+1 system, only allows one UPS down; while for the modular UPS system, taking 4+1 as example, the reliability is lower than that of 1+1 system when 100% load, but when 75% load rate, modular system becomes a 3+2, then a 2+3 when 50%, the reliability is much larger than the 1+1 system. In the common application situation, the UPS load rate is about 20~40%, in this case the modular has a very obvious advantage.

Secondly, different from the traditional single UPS, modular UPS can easily achieve the redundancy mode such as N+2, N+3, which only need to add 1-2 modules. But if tower type UPS need to achieve this mode, should not only increase 1 hosts, but also transportation, site installation, machine alignment design and the corresponding distribution, the battery needs to change, resulting in a substantial increase in investment.

In summary, the reliability of UPS modulares in the application is much higher than the traditional tower UPS; coupled with the characteristics of rapid maintenance and expansion of UPS, the availability of modular UPS is much higher than the traditional tower UPS.

SOROTEC exhibit at the Middle East Electricity2017(Solar Middle East). Looking forward to meeting you here. Booth: Z2 B30.

1.Solar power inverter requires high efficiency. Due to the high price of solar cells, in order to maximize the use of solar cells, improve system efficiency, we must try to improve the efficiency of the solar inverter.

2.Solar inverter requires high reliability. Solar power generation system is mainly used in remote areas, many power station unattended and no maintenance, which requires the inverter with a reasonable circuit structure, strict screening of components, and requires the solar system inverter with various protection functions, such as input DC reverse polarity protection, output short circuit protection, overheating protection, overload protection etc..

3.Solar inverter requires a wide range of DC input voltage. The solar battery terminal voltage varies with load and sunshine intensity, although the voltage of solar cell battery plays an important role, but because of the battery voltage fluctuate varies with the change of residual capacity and internal resistance of battery, especially when the battery aging, the change range of terminal voltage is very wide, such as 12V battery, the voltage can be the change in 10V ~ 16V, which requires the inverter must ensure the normal operation in a wide range of DC input voltage, and ensure the stability of output voltage.

4.In the middle and large capacity solar power system, the output of the inverter should be a sine wave with small distortion. This is because in the middle and large capacity system, if use square wave power supply, the output will contain many harmonic parts, which will produce additional losses. Many loads of the solar power system is a communication or instrumentation equipment, these devices have higher requirements on the quality of the power grid. In order to avoid the pollution of the power grid, the inverter output sine wave current is needed.

Learn more about SOROTEC SSP3118C off grid solar inverter specifications

1.Whether online interactive UPS in the normal city power supply, or power supply interruption, both power supply from the battery to the inverter, in the meantime, the power supply to the load is provided by the inverter of the UPS. This basically eliminates the impact of any voltage fluctuations and interference from the city power grid on the load, the realization of the load without interference voltage regulator. At present, the online interactive UPS on the market can achieve regulated power supply to the load, when the voltage range of 180 ~ 250V, the general output voltage stability can reach 220±6.6 V.

2.Online interactive UPS sine wave output waveform distortion coefficient is relatively small. At present, the distortion coefficient of the products sold in the market is less than 3%.

3.When the power supply interruption, the line interactive UPS system can achieve the real uninterrupted power supply to the load. UPS manufacturer found that it is because as long as the internal battery can supply power to the inverter, when the city power is interrupted, online interactive UPS supply power to the load by the inverter as normal. Therefore, the interruption of power supply or not, the UPS does not have any internal conversion action. Therefore, in the process of city power supply switch to the interruption, conversion time of UPS power supply to the load is zero.

4.Compared with the off line UPS, the online interactive UPS has excellent characteristics of output voltage transient. Generally, when the full load to no-load transformation, the output voltage range of 4%.

5.Online interactive UPS generally uses PWM pulse width modulation technology, so the noise is relatively small.