2. Dynamic testing
(1) Sudden increase or decrease load test
First, use a “power disturbance analyzer” to measure the phase voltage and frequency under no-load and steady-state conditions. Then, suddenly increase the load from 0 to 100% or suddenly decrease the load from 100% to 0. If the UPS output transient voltage is between -8% and 10% and returns to steady state within 20ms, then this UPS indicator is qualified; If the transient voltage output of the UPS exceeds this range, it will generate a large surge current, which is extremely detrimental to both the load and the UPS itself. Therefore, this type of UPS should not be selected.
(2) Conversion characteristic testing
This mainly tests the conversion characteristics when converting from inverter power supply to mains power supply or from mains power supply to inverter power supply. During testing, it is necessary to have a storage oscilloscope and a voltage regulator that can simulate changes in the mains power.
3. Other routine tests
Overload test
Overload testing is of great concern to users and is also an important indicator for measuring UPS power supply. Overload testing is mainly used to test the overload capacity of the entire UPS system, ensuring that even in the event of overload during operation, the UPS can maintain a certain period of time without damaging the equipment. Overload equipment must be tested according to equipment specifications and conducted at room temperature below 25 ℃.
Input voltage overvoltage and undervoltage protection test
According to the equipment specifications, the allowable range of input voltage variation is tested. Generally, UPS allows an input voltage variation of 10%. When the input voltage exceeds this range, an alarm should be triggered and the rectifier should be switched to battery power supply. The rectifier should automatically shut down. When the input voltage returns to the rated allowable range, the equipment should automatically resume operation, that is, the battery should be automatically released and switched to mains power operation. During the automatic activation and deactivation of the battery, the waveform of the UPS output power supply should remain unchanged.
discharge test
The discharge test mainly tests the performance of the battery. During the discharge test, firstly, the discharge time should be recorded; The second is to observe the output voltage waveform and discharge protection value during discharge; Thirdly, it is necessary to check whether there are “outdated” batteries. Before the discharge test, the battery must be continuously charged for 24 hours without interruption.