Uninterruptible Power Supplies (UPS, UPS); It has been used for many years for the power protection of systems that collect, process and store information, which is considered critical load. Critical applications where UPSs are widely used include Data Centers, IT Networks, Financial Services, Telecommunications and Industrial Processes. It is essential that the systems used in these applications, whose developing and technical infrastructure becomes increasingly complex, are powered by stable and reliable power sources. UPSs that will isolate the load from all power quality-related problems that occur in the network, including voltage outages, must meet certain technical criteria. The issues to be looked at in these criteria are as follows: efficiency, input performance, output performance, communication, battery management, load compatibility, etc.
Hi-Tech Pro UPS, which Tunçmatik A.Ş. offers to the market as a professional power protection solution, meets these criteria while maintaining its operating performance. In this article, the prominent advanced features of Hi-Tech Pro UPS will be briefly discussed, taking into account the aforementioned criteria.
Transformer-Free Structure: In new UPS technologies that offer improvements in power factor (GF or PF) and input current Total Harmonic Distortion (THDi) related to input power, there is generally no power transformer at the output. Not using the output transformer causes a significant reduction in the weight of the UPS and the residential volume where it will be installed. In addition, by not using the transformer, power losses in the copper windings and iron body are eliminated and the output power stage efficiency of the UPS system is increased. In traditional UPSs, the output (load) voltage matching of the transformer is ensured by keeping the inverter input voltage high.
Eco-Mode: Conventional UPSs receive their input power from a single source. This source is the AC power grid that feeds both the rectifier and the bypass line. If there is a reliable backup power source in the enterprise (such as a cogeneration system or an independent power transformer output) to which the bypass line can be connected and which can feed the loads at the output of the UPS, the bypass line can be connected to this voltage source and the UPS can be operated in eco-mode. In this way, the total efficiency of the UPS increases to 97-98% since the load current does not flow through the rectifier and inverter.
Parallel Operation: In very critical applications, the Mean Time Between Two Failures (MTBF) can be increased by parallel connection of UPS devices. The increase in the number of UPS modules operating in parallel ensures that the load supply can be continued without interruption in case a UPS module is disabled due to malfunction or maintenance. Apart from backup, UPS devices are also connected in parallel to increase the power protection capacity required by the increase in the business’s future business volume. Max. without needing additional hardware. A power backup solution with high system integration can be obtained by connecting 8 Hi-Tech Pro UPS devices in parallel.
Distortion: Total Harmonic Distortion (THD) is defined for two electrical quantities of the UPS: Input current and output voltage. Regardless of which side and for which electrical quantity it is defined, it is desired that the THD value be at low levels, regardless of the load ratio and load type. Input current THD value of Hi-Tech Pro UPS is <1% at full load; At 10% load, < is 5%. These values show that sinusoidal currents with minimum harmonic power losses will be drawn from the network. Similarly, the voltage distortion at the UPS output is <0.5% for linear loads; For non-linear CF=3 loads, <%2. These values for input and output are extremely low and mean that the Hi-Tech Pro UPS exhibits almost ideal power supply behavior, regardless of load and source (UPS, resistive load behavior for the mains input; ideal voltage for the critical load it feeds). source behavior).
Power Factor: The power factor (GF) magnitude is defined for the powers drawn from both the output and the input, such as distortion. In order for the UPS not to draw reactive power from the network to which it is fed, in other words, in order for the enterprise not to pay unnecessary reactive power fees to the electricity institution for this power that it does not use as useful power, the power factor value must be close to ‘1’ in all practical loading rates. Hi-Tech Pro UPS prevents the UPS from drawing reactive power from the source it is connected to by providing PF>0.99 in a wide load percentage range of 10%-100%.
Efficiency: The efficiency value, defined as the ratio of output active power to input active power, provides information about the power losses occurring in the UPS. In an ideal UPS device, the efficiency value is ‘1’ for the entire load range. However, this value is not possible due to the lossy elements and switching of power semiconductors (IGBT, diodes, etc.) through which the current in the UPS passes. Especially in semiconductor elements such as MOSFET and IGBT that operate at high switching frequencies, switching losses can be very high depending on the frequency. In order to transfer this power loss, which occurs in the form of heat, to the external environment, it becomes inevitable to choose large sizes of coolers and fans used in the UPS and to use a high BTU cooling system in the UPS room. Hi-Tech Pro UPS exhibits a superior operating performance with a low loss compared to its peers, with an efficiency value of 95% in the load range of approximately 20-100%.
4th Generation IGBT Technology: Trench Gate is the 4th in 4 structure. Hi-Tech Pro UPS, using 2nd generation IGBT elements, provides operation at higher frequencies with less power loss at lower acoustic noise levels as a result of improvements in switching characteristics. The fact that the output voltage and input current waveforms are very close to pure sinusoidal form is due to the operation of IGBT elements that respond quickly to control algorithms.
Zone Rectifier: Hi-Tech Pro UPS has a special feature that provides energy saving depending on the application. The rectifier circuit performs inversion as well as rectification. In an operating regime in which the load fed by the Hi-Tech Pro UPS does not consume electrical energy, on the contrary, it produces it (e.g., during braking of an ac motor type load it feeds), this energy produced is transferred to the network via the DC intermediate circuit and rectifier. In the absence of such a feature, this regenerative power, which will cause the DC intermediate circuit voltage to rise and possibly be transferred to the bypass line of the UPS, is sent to the grid by the operation of the rectifier circuit in inverter mode. In addition to providing safe operation, this feature also saves energy on the UPS.
Communication Capability: Local or remote monitoring of the UPS device is a feature sought by the user in case of device intervention or regular monitoring of operating parameters. Wide range of communication possibilities provide flexibility to the user. In addition to local communication via RS-232, Hi-tech Pro UPS can inform the user about the operating status of the UPS by sending e-mail and text messages; When used with a network adapter card, it allows remote management over the internet; It allows remote monitoring via SNMP card or GPRS adapter.
UPSs are indispensable power protection solutions for production continuity. UPSs, which use semiconductor elements applied by mW level powers from the control terminals, can feed critical loads that draw high power. In this article, the important technological developments provided by the rapid developments in semiconductor and microcontroller elements in UPS devices are presented on an example UPS device.