The basic principle of pulse width modulation (PWM): The control method is to control the on and off of the switching device of the inverter circuit, so that the output end can get a series of pulses with equal amplitude, and use these pulses to replace the sine wave or the required waveform. That is to say, a plurality of pulses are generated in the half period of the output waveform, so that the equivalent voltage of each pulse is sinusoidal waveform, and the output is smooth and the low-order harmonics are few. By adjusting the width of each pulse according to certain rules, the output voltage and frequency of the inverter circuit can be changed.
For example, by dividing the sinusoidal half-wave waveform into N equal parts, the sinusoidal half-wave can be regarded as a waveform composed of N pulses connected to each other. The pulse widths are equal to ∏/n, but the amplitudes are different, and the top of the pulse is not a horizontal line, but a curve. The amplitudes of each pulse change according to the sinusoidal law. If the above pulse sequence is replaced by the same number of equal amplitude and unequal width rectangular pulse sequence, the midpoint of the rectangular pulse and the corresponding sinusoidal equivalence midpoint coincide, and the rectangular pulse and the corresponding sinusoidal part area (impulse) is equal, a set of pulse sequence is obtained, which is called PWM waveform. It can be seen that the pulse width varies according to the sine rule. According to the same impulse equivalent effect, the PWM waveform and the sine half wave are equivalent. For sine negative half cycle, PWM waveform can also be obtained in the same way.
In the PWM waveform, the amplitude of each pulse is equal. To change the amplitude of the equivalent output sine wave, only the width of each pulse can be changed according to the same proportion coefficient. Therefore, in the AC-DC-AC inverter, the output pulse voltage of the PWM inverter circuit is the amplitude of the DC voltage.
According to the above principle, the width and interval of each pulse in PWM waveform can be calculated accurately after the sine frequency, amplitude and the number of pulses in half period are given. According to the result of calculation, the PWM waveform can be obtained by controlling the on-off of all switching devices in the circuit.
Outdoor stainless steel cabinet technology is constantly improving, so that stainless steel cabinet has the best anti-vibration, anti-impact, anti-corrosion, anti-dust, waterproof, anti-radiation performance, in order to ensure that the equipment works stably and reliably. All designs are people-oriented, so that users can use more smoothly, SOROTEC focused on stainless steel outdoor cabinet technical design, and technical updates.
Stainless steel cabinet is the most commonly used toughened glass doors and mesh doors. And its quality plays a key role. Usually, the front and rear door panels are never allowed to have distortion, expansion, depression, burrs and other phenomena, its flatness is usually less than 2 mm. The difference in the same slot also needs less than 2 mm, and the installed door panels can not have obvious upward or downward adverse phenomenon, to ensure the flexibility of disassembly and assembly. When opening and closing the door, it must be flexible. The angle should be greater than or equal to 90 degrees. It is forbidden to damage spraying when the door rotates.
Only paying more attention to the small details of stainless steel cabinet doors will help attract more customers. Different types of doors will directly affect buyers’ decision to make purchases.
■.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
With the large-scale construction of data center, users pay more attention to energy cost and efficiency. The future development direction of power supply technology in data center must be direct power supply technology. While eliminating the traditional UPS equipment investment and site occupation and reducing the early cost, it also reduces the later operating cost by reducing conversion stages and improving power supply efficiency. And what is said here to improve efficiency, not only refers to the high efficiency of the grid side to the input side of IT equipment on the supply circuit path, but also the high efficiency and green of primary energy side to the CPU and other energy path. Although the PUE value of traditional concept is likely to increase, the energy consumption per unit calculation is reduced. The overall development trend of power supply technology in future data centers is that high voltage/centralized/AC large UPS will develop towards low voltage/distributed/DC small UPS, from centralized lead-acid batteries in computer rooms to distributed lithium batteries embedded in IT cabinets and even servers, from polluted fossil fuels to environmentally friendly green energy sources. .
The core of uninterruptible power supply technology in data center is uninterruptible power supply and its battery, so different battery connection positions also determine different power supply architecture. At present, the backup battery voltage of the industry mainstream from high to low has more than 400 volts of UPS, to 380V, 240V and 48V of DC power supply, and even 12V of batteries embedded in IT equipment. There are even small UPS with flywheels of medium voltage or lower voltage such as 5V. The closer the battery is to the terminal server motherboard or CPU, the more decentralized the power supply system, and the more distributed the corresponding IT system; the closer the battery is to the terminal, the higher the customization degree of the power supply system, the greater the difficulty for ordinary users to carry out the scale; the closer the battery is to the terminal, the higher the control and management level of IT power supply and battery required. Finally, the closer the battery is to the end, the smaller the transition stages from the grid to the CPU supply path, resulting in higher conversion efficiency, but the transmission loss may increase on the low-voltage side. Therefore, compared with centralized and distributed, high-voltage or low-voltage, AC or DC, the choice of different power supply structure will greatly affect the reliability of the power supply system, power supply efficiency, cost, and so on, as well as the maturity of technology, ecology and application flexibility.
In addition, with the development of battery technology and the introduction of green energy such as wind energy, solar energy and fuel cell into the data center, more opportunities and challenges are brought to the data center. In a sense, the technology of uninterrupted power supply in data centers will ultimately depend on the development of battery technology, and battery innovation will bring changes in the power supply architecture of data centers. For example, with the development of technology from traditional low-density lead-acid batteries to high-energy-density lithium batteries, backup batteries are likely to be replaced by IT cabinets or even placed inside IT devices. With the development of the same battery technology, it is possible to realize the energy storage of wind energy, solar energy and other volatile green energy. It will also change the traditional data center from a single grid power supply mode.
1.Superior energy saving and environment-friendly:
Efficiency > 96% at 50%-75% rated load, and > 95% at 25% rated load; Input PF > 0.99,input THDi<3%.
2. Superior capability of powering load:
Output PF is 0.9 or 1, no need of power deration with load of leading or lagging PF.
Top or bottom cabling, no need of input cabling cabinet.
Full front access, UPS, failed part can be replaced shortly.
The number of battery cells can be configured flexibly, so the original batteries can be used when modifying the legacy system; moreover, the battery cell can be replaced in time when it fails
without interrupting the normal operation of UPS.
6.6-inch extra large LCD that can display 12 language (Chinese ,English ,Russian, French ,Spanlish and so on).
7.Provide large LCD touch screen (optional).
8.Each UPS modules provide 4.5KW charge capacity. equivalent to 10 to 12A.
9.On-Line Double Conversion, fully isolating the influences of power grid pollution and power failure from utility power supply and diesel generator to load.
10. Advanced DSP full digital control technologies realize higher system stability, online capacity expansion and maintenance.
11.Advanced distributed active parallel technology realizes parallel operation of 4 UPS units and online capacity expansion without centralized bypass cabinet.
12.Digital load sharing technology features extra low cross current and extreme high system reliability in parallel operation.
13.Adaptive to severe power grid environment due to extra wide input voltage and frequency ranges.
14.Extra strong capability to withstand output overload and short circuit, ensuring the system stability and system safety at limit conditions.
15 Intelligent battery management maintains battery automatically to prolong the battery life.
16. Efficient heat dissipation and effective protection under severe environment due to its independent layer-sealed ventilation channel and redundant fan design, as well as the paint-protected
circuit boards and built-in dust filter.
17.Applicable voltage south America.
Since only 5% allowable voltage range under the 12V bus structure, the discharge of the battery-mounted bus will be very narrow in the voltage range. Even if a DC / DC regulator is added, the allowable battery discharge time will be less, because the power supply under-voltage protection circuit will be triggered very quickly. There is also the risk of heat dissipation under 12V low voltage and high current, so it is difficult to have a long battery standby time under the 12V bus structure. If the 48V bus structure is adopted, the battery can be directly connected to the 48V output bus because of its wide voltage allowable range, so the battery standby time can be longer, and the system security and reliability can be effectively guaranteed. These characteristics have been fully verified in the communication industry.
1.Hot Swappable Easy to Maintance
2.Smart Monitor Control System
3.Various Human-computer Interface
4.Protection Degree: IP55
5.Adopt advanced MCU microprocessor control technology.
6.Advanced MPPT Technology, High converting efficiency higher than 97% for minimizing energy loss.
7.Reversed current protection at night, over voltage and reverse polarity protection.
8.Capable of selecting different charging mode for various types of batteries.
10.Industy-leading power density compact size and high reliability.
11.Doorframe designed with waterproof structure, posted on the seal and equipped with waterproof lock on the door double insulation design.
12.Cabine adopt quality galvanized sheet or aluminum coated steel sheet as material, surface coating anti-UV power.
13.Suitable for outdoor installation.
When I think of the off grid solar applications, one main sector that has tremendous captive power requirement is telecommunications. With consistent fall in the average revenue per user and a whopping 86% increase in the minutes of usage in the past decade, India is one of the countries with increasing market competitionand highest number of MoU’s. The numbers of operators have almost tripled in the last 3 years and there is a mad headed competition to reduce the cost especially if theservices have to be made affordable to the sub urban and rural areas. Rural teledensity improvement is possible only with low cost service.
With power contributing to 25% of total network cost, one of the key areas where the telecom providers are looking forward to reduce cost is energy. Unfortunately, poor quality of grid supply in suburban and semi-rural areas and no grid supply at many rural areas is increasing the energy cost for the telecom providers. 10% of telecom towers in India have no power supply while almost 50% have less than 12 hours of grid supply. Even in those 12 hours of grid supply there are problems of low voltage, single phasing and fluctuations that necessitate the use of diesel genset round the
clock. The increasing energy cost, uncertain grid power and lower affordability of rural people is having a double warming effect to the telecom service providers.
According to Telecom Regulatory Authority of India (TRAI), Close to 300000 towers in India consume more than 2 billion liters of Diesel every year generating 5.4 millionTons of CO2. The increasing diesel prices and the mounting pressure of minimizingcarbon offset makes diesel based captive power a less viable option in long run. Solar PV based captive power would be the ideal solution for the telecom service providers. They have many advantages that would favor them for incorporating solar energy to power their towers.
Huge energy savings are possible by use of Solar Diesel hybrid (65% savings) as compared to relatively less savings by use of biomass power (29% savings). Also there is a possible 40% reduction in site maintenance expenditure for the companies who install solar as compared to the use of diesel genset. With the use of batteries it is even possible to power the towers during the night time and effective diesel usage hours can be reduced to as low as 8 hours per day.
The huge existing tower base that require captive power and further network expansion by service providers who promise to offer seamless network coverage makes it easy for solar to penetrate into the telecom industry very soon. Most of the towers that need off grid power are located at a place where there are no space limitations and this makes solar PV as an ideal choice. Also, network uptime can be managed in difficult hilly and terrain regions with the use of solar power.
The solar powered telecom towers are also expected to scale up by another one lakh next year and it is important to note that the newer telephone towers are being installed based on a new technology that will consume less power and also do away with the air conditioning so critical to the telephone towers. For the newer towers, where air conditioning is not a requisite, it makes more sense to use solar power, especially where the EB electricity is not available for considerable duration
The 5% soft loan and 30% capital subsidy would obviously attract telecom service providers to opt solar power. Also, 90% capital subsidy by NSM in remote areas & special category states and Telecommunications Universal Service Obligation’s funding for the use of renewable energy in remote areas will increase the market adoption of solar for telecommunication industry.
Captive solar is possibly the best way to increase rural footprint of telecom service providers at an affordable cost, thereby improving the rural community access to communication. Certain telecom service providers have realized this and initiatives have been planned for no grid and poor grid regions. If successful proof of concept is available and telecom service providers are able to reduce the network operation cost, it will increase the market penetration of solar PV for captive power in the telecom industry. Sorotec is committed to the communications industry for decades and has a complete and efficient solar base station solution. Provide users with reliable power protection, while greatly improving the return on investment of users.
SOROTEC Solar powered telecom base station (BTS)-SHW48500 the monitor module and PV MPPT module, wind power module, rectifier module, distribution frame (or cabinet) composed of communication power supply system, power supply system to achieve the man-machine interface operation, system status monitoring, data upload, intelligent battery management module and automatic energy saving management. SHW48500 monitoring module provides RS232/RS485, network port, dry contact and many other communication interfaces. It is flexible in networking and can realize remote monitoring and widely used in 4G & 5G telecom base station(BTS).
1.Adopt advanced MCU microprocessor control technology.
2.Advanced MPPT Technology.High converting efficiency higher than 97% for minimizing energy loss.
3.Reversed current protection at night.over voltage and reverse polarity protection.
4.Capable of selection different charging mode fo various types of batteries.
6.Industy-leading power density compact size and high reliability.
7.Doorframe designed with waterproof structure, posted on the seal and equipped with waterproof lock on the door double insulation design.
8.Cabine adopt quality galvanized sheet or aluminum coated steel sheet as material, surface coating anti-UV power.
9.Suitable for outdoor installation.
10.With remote monitoring system aperation.