Basic issues with UPS power supply, which type of load generally has stronger capacity for UPS? Generally, UPS is designed for inductive loads, so carrying inductive loads is its duty. The capacitors connected in parallel at the output end of a typical UPS inverter serve both as filters and as offsets for inductive components in the load. If the load is capacitive, how can we use capacitance to offset the capacitive component? Only by increasing the output capacitance component, and the current of these capacitance components must be provided by the inverter, can the active component output by the inverter be reduced, so the carrying capacity is weakened. What are the functions of STS, LBS, and dual bus? The function of STS (Static Switch) is to switch between two input AC currents. The function of LBS (Synchronizer) is to synchronize two sets of UPS, with the aim of achieving zero switching time for STS. The function of dual bus is to provide redundant power supply for electrical equipment. What are the advantages and disadvantages of power frequency machines compared to high-frequency machines?
Power frequency UPS: Disadvantages include low input power factor, high power consumption, low efficiency, large size, bulky, high price, and low feasibility. Advantages include relatively easy manufacturing, especially with minimal impact from manual labor, and relatively low consistency requirements. High frequency UPS: Advantages include high input power factor, low power consumption, high efficiency, small size, lightweight, and high reliability; But it requires high standards for production methods and strict consistency.
When selecting input/output circuit breakers for UPS, the first requirement is that the rated voltage of the circuit breaker should meet the rated input/output voltage of the UPS. For example, a single input/output UPS can choose a single pole (or N+1, or two pole) circuit breaker with a rated voltage of AC220V or 250V, and a three input/three output UPS can choose a three pole (or N+3, or four pole) circuit breaker with a rated voltage of AC380V or 415V. It should be noted that the rated breaking capacity ICU of the circuit breaker should meet the requirements of the UPS manufacturer. Generally, small UPS heads should be 10KA or 6KA, and large and medium-sized UPS heads should be above 30KA. The connection between UPS and external long delay batteries should not be too long, otherwise the voltage drop lost on the battery connection will be too large. In addition, users often pay close attention to the temperature and humidity of the UPS host’s working environment. Placing the battery together with the host can also provide a good working environment for the battery. It is recommended that users set up separate distribution panels (cabinets) for UPS and its loads to facilitate centralized and reliable control of UPS and its protected loads. This distribution panel (cabinet) must comply with relevant national standards.
The digital signal controller (DSP) used by UPS combined with digital Hall sensor devices achieves 100% digital operation of the UPS system. A redundant system with multiple microprocessors is also adopted, using multiple microprocessors with independent power supplies to control rectifiers, inverters, and internal static bypasses, thereby improving the digitalization and reliability of the system.
At present, intelligent UPS power supplies have operational performance characteristics such as communication with microcomputers and program control. Install the corresponding software on the microcomputer, connect the UPS power supply through the serial/parallel port, run the program, and use the microcomputer to communicate with the UPS power supply. Generally, it has functions such as information inquiry, parameter setting, timing setting, automatic shutdown, and alarm. Like Winpower. Then, by controlling the cable through a dedicated serial port, connect the UPS power supply to the computer, and communicate through RS232 and RS485 protocols, the UPS power supply can automatically shut down when there is no mains input and low battery. And it can simultaneously monitor multiple UPS power supplies connected to multiple serial ports.