Weak current College】 【UPS product evaluation mode】.

<br> UPS system test test UPS aims to identify the actual specification UPS can meet use requirement. UPS testing typically involves steady-state test and dynamic tests. Steady-state test is unloaded, 50% of rated load, and 100% of rated .load conditions, the test input, output, end-of-phase, line voltage, no-load loss, power, efficiency, output voltage waveform, distortion and output voltage frequency, etc. Dynamic load test generally in mutant (generally choose load from .0-100% and 100% -0), test the UPS output voltage waveform changes to test the dynamic nature of UPS and energy feedback pathway. <br> Steady-state test <br> The so-called steady-state test refers to .the device enters the "normal" State of the test, usually measured waveform and frequency and voltage. <br> Waveform <br> General is unloaded and loaded state, observing the waveform is normal, distortion measurement apparatus, measuring the output voltage waveform distortion .. Under normal operating conditions, load resistor, distortion measurement instrument for measuring the output voltage, total harmonic relative content should conform to the requirements of the product, typically less than 5%. <br> Frequency <br> Generally available oscilloscope measurements output voltage .frequency and use the "power disturbances Analyzer". At present the UPS output voltage frequency generally meets the requirements. But when the frequency of UPS, local oscillator circuit not sufficiently precise, it is also possible in the AC frequency instability, the UPS output voltage .frequency with change. UPS output frequency accuracy in General and AC synchronous, and negative 0.2% can be achieved. <br> Output voltage <br> The UPS output voltage can be tested to determine: <br> A, when the input voltage of .90% of the rated voltage and output load to 100% or input voltage of 110% of rated voltage, output load of 0, the output voltage should be kept rated value of plus or minus 3% range. <br> B, when the .input voltage to the rated voltage of 90% or 110%, the output voltage of a phase is unloaded, the other two phases at 100% load, the output voltage should be kept rated value of plus or minus 3% phase difference, its scope .should be kept at 4 ° c range. <br> C, when UPS inverter input DC voltage variation of plus or minus 15%, the output load of 0-100% change, its output voltage values should be kept rated voltage value plus or .minus 3% range. This indicator on the surface, and the indicators described above, but in fact it repeatedly than previous index higher demands. This is because the control system of the input signal changes in the broader context, to demonstrate obvious nonlinear characteristics, .to make the output voltage does not exceed the allowable range, on the circuit require even higher. <br> Efficiency <br> UPS efficiency by measuring the UPS output power and input power. UPS efficiency mainly determined by the design of the inverter. Most .UPS only in 50% -100% load is relatively efficient, when less than 50% of the load is, its efficiency is a sharp decline in the efficiency indicators provided by the manufacturers or more is rated DC voltage, rated load conditions of efficiency. .The best choice when the user selection efficiency and output power curve and DC voltage change when the positive and negative 15% efficiency. <br> Dynamic test <br> 1, sudden or sudden reduction in load test <br> To use the "power .disturbances Analyzer "measurement of no-load, steady voltage and frequency, and then sudden load from 0 to 100% or sudden load reduction from 100% to 0, if the UPS output transient voltage in the-8% to 10%, and restore .-to homeostasis 20ms, this UPS the index; if the UPS output transient voltage outside this range, it will have a greater surge current, regardless of the load or on the UPS itself is extremely unfavorable, that UPS is not suitable for use. < .br> 2. conversion characteristics test <br> The main test by the inverter mains supply or converted to AC power to the inverter power conversion features. Tests required for the storage oscilloscope and can simulate a regulator power supply changes. <br> Other general .test <br> Overload test <br> Overload test is extremely concerned about the user, as well as UPS power, an important indicator. Overload test is testing the ability of the UPS unit, even if the load operation has overload phenomena, UPS can .maintain a certain time without damaging the device. Overload device must be tested by device index and to 25oC within the room temperature. <br> Input voltage, over-voltage, under-voltage protection test <br> Press the device index input voltage variation .range for testing allowed, general UPS allows input voltage variation of 10%, when the input voltage exceeds the scope should be alert, and converted to automatic battery, Rectifier, off when the input voltage is restored to rated allowable range, the device should automatically .resume operation, that is, automatic discharge of the battery to run the utility. In automatic operation and lift the battery, the UPS output power waveform should not change. <br> Discharge test <br> Discharge test is primarily a test battery performance. .Discharge test, one is to record the discharge time; second, it is necessary to observe the discharge output voltage waveform and discharge protection value; the third is to check whether there is "behind" the battery discharge test must be made to the battery for .24-hour nonbreaking charging. <br>.