Power Inverter buy points

How to choose the correct ups power inverter mainly pay attention to the following points .
1 , the rated output voltage: within a predetermined fluctuation range of the input DC voltage is allowed , it means that the rated voltage of the inverter should be output . The stability of rated AC power inverters output voltage accuracy is generally defined as follows : In steady-state operation , the voltage fluctuation range should be a limit , such as the deviation does not exceed the rating of ± 3% or ± 5%. Under load mutations or other interfering factors affecting the dynamics of the output voltage deviation should not exceed the rating of ± 8% or ± 10%.
2 , the output voltage imbalance : Under normal operating conditions, the inverter output phase voltage unbalance ( reverse component of the ratio of positive sequence component ) should not exceed a specified value , usually expressed in% as 5 % or 8 %.
3 , the output voltage waveform distortion : When the inverter output voltage is sinusoidal , shall specify the maximum allowable waveform distortion ( or harmonic content ) . Usually to a total distortion of the output voltage waveform that its value should not exceed 5% ( 10% single phase output enable ) .
4 , rated output frequency of the vehicle power inverters inverter output AC voltage frequency should be a relatively stable value , usually frequency 50Hz. Under normal operating conditions the deviation should be within ± 1 %.
5 , the load power factor : the ability to characterize the capacitive load inverter with inductive load or . In the sine condition, the load power factor of 0.7 to 0.9 ( hysteresis ) , the rating is 0.9 .
6, rated output current : Indicates the inverter within the specified range of the rated output power factor of the load current . Some inverter products given is rated output capacity , the unit in VA or KVA said . The rated capacity of the inverter when the output power factor of 1 ( ie, purely resistive load ) , the rated output voltage of the rated output current of the product.
7 , rated output efficiency: The efficiency of the inverter under specified operating conditions , the output power to input power ratio , in%. Inverter efficiency at rated output capacity for full load efficiency of 10% at rated output capacity efficiency at low load efficiency.
8 , Protection: over-voltage protection : No voltage stabilization measures for the inverter output over-voltage protection measures due to the negative output cut from overvoltage damage.
Overcurrent protection : inverter over-current protection , should be able to ensure that a short circuit in the load current exceeds the allowable value or action from time to time , so from inrush current damage.
9 , starting characteristics : characterizing the performance of the inverter starting with a load capacity and dynamic work. The inverter should ensure reliable starting at rated load .
10 , the noise : the transformer power electronic device , the filter inductor , electromagnetic switches and other components are the fan noise is generated . Normal operation of the inverter , the noise should not exceed 80dB, small inverter noise should not exceed 65dB.