When choosing a UPS Battery, you need to consider the problems that need to be paid attention to from all aspects.
(1) First of all, we should pay attention to whether the UPS Battery machine has synchronous switching function. At present, in addition to the rated output power less than 500kVA square wave output off-line UPS Battery is still using the conversion control without mains synchronization function, all the output power of 1KVA and above UPS Battery in the implementation of mains power supply to inverter power supply conversion operation, should have mains synchronous switching function. To ensure that the inverter and the bypass power supply have the same phase and frequency output characteristics. Because the consumability of UPS Battery manufacturers' product phase-locked synchronization circuit is quite different, users should pay attention to the working characteristics of the phase-locked synchronization circuit when purchasing UPS Battery.
· The phase-locked synchronization control circuit has a strong phase-locked synchronous capture ability of the mains input voltage, which is mainly manifested in that the mains sine wave can synchronize control of the inverter output sine wave when the UPS Battery has a wide range of mains input voltage changes.
· When the UPS Battery is switched over, the smaller the phase difference between the AC bypass power supply and the inverter power supply, the better. The frequency stability of the power supply network should be considered in the application situation. If the use of mains, the general online UPS Battery with the control circuit can meet the requirements. For small power grids with large frequency fluctuations, the UPS Battery with appropriate functions should be selected in order to successfully realize synchronous switching operation.
(2) Impact resistance to capacitance load. For rectifying and filtering loads, the peak current provided by the UPS Battery is much higher than the peak current required to drive the resistive load, since the rectifier is connected with a large capacity filtering capacitor behind it. The index to measure the capacity of capacitive load is the peak coefficient. It is defined as the ratio of the maximum capacitive peak current produced by the same sine-wave AC power supply with rectified filter load to the maximum peak current produced by the pure resistive load. The above comparison is made on the premise that capacitive loads and resistive loads have the same impedance values. In this way, the UPS Battery cannot work properly due to excessive load impact and capacitor damage.
