Power supply design and production
DC UPS-300 - Uninterruptible power supply with dc output voltage 300 Vdc
DC UPS-300 function
DC UPS-300 provides uninterruptible working of computer and telecommunication equipment normally supplying form classic 230 Vac line voltage, 300 W max. power.
Such kinds of equipment, on their input, have rectification of line voltage, without line transformer. From the line voltage rectifier generates about 300 Vdc, which means that such devices could be supply with 300 Vdc instead 230 Vac line voltage.
That possibility utilize DC UPS-300. On its output DC UPS- 300 make dc voltage (about 300 Vdc), which is given by rectification of 230 Vac line voltage, when line voltage exist. When line voltage is not present dc output voltage is given by converting of 48 Vdc input voltage (batteries), which is always present on reserve voltage input of DC UPS-300. This kind of voltage (48 Vdc) is available in systems, which have uninterruptible dc power supply (for example, telecommunication companies, railroad companies, power distribution companies, etc..).
When reserve 48 Vdc voltage is not present near consumer equipment, external AC/DC battery charger and set of batteries must be providing. Replacement of batteries in such solution can be done without interrupting power supplying from DC UPS (if line is present) – “hot” replacement.
Switching from ac line supplying to reserve battery supplying and vice-versa, is going without time period of output voltage interrupt (when output voltage do not exist or going to undervoltage values in classic UPS supplies). That can be accomplished because on output of DC UPS, dc voltage given from rectified ac line voltage and dc voltage given from dc/dc converter is adding; their sum is output dc voltage of DC UPS. Unlike from this solution, at output of classic AC UPS exist interrupt in energy supply in period 5-15 ms, because of adding ac voltages, which are not synchronous.