Power factor (pf) is the difference between the actual energy consumed in an AC circuit and the apparent power. It will be calculated as a decimal or percentage between 0-1 pf and 0-100%, i.e. 0.9 pF=90%.
Meaning of UPS power factor
UPS input power factor
UPS input power factor is the ratio of
UPS input active power to input power. UPS is not only a part of the power supply, but also the load of the mains power supply. This means that UPS power not only receives active power from the mains, but also reactive power.
UPS rectifiers have reactance and capacitance components, therefore they also have factor power when making upstream electrical connections
This must be considered. UPS input is a design feature typically declared by the manufacturer in technical specifications.
Using modern IGBT front-end rectifier technology, the input is usually close to the unit at 100% nominal load, with a value of 0.99.
The rated output power factor of UPS is the design factor of UPS
The rated output pf describes the maximum effective load and apparent load that UPS can withstand in design. For example, a 100 kVA UPS pf 1.0 can handle loads up to 100 kW. If the pf is 0.8, these loads will become 80 kW and 100 kVA respectively. To select UPS correctly and determine its size, you should know the total active power and apparent power of the load. UPS with a rated power factor of 0.8 can also handle loads with higher coefficients, and vice versa.
Lagging power factor
In these loads, the coefficient of the current waveform lagging behind the voltage is equal to the reactance of the load, usually between 0.5 and 0.95.
In the figure below, the actual value of the 2300 VA load with a lag of 0.766 pf is 1762W (1.76 kW).
Unity power factor
The current and voltage waveforms of the Unity pf load are in phase with each other. In the following example, the actual value of a 2300 VA load with 1 pf is 2300 W (2.3 kW).
Leading power factor
A load with a leading pf has a current waveform that leads the voltage by a coefficient equal to the load reactance, typically between 0.8 and 0.95.
Using the same 2300 VA as the previous example, with a leading pf of 0.766, the actual value is 1762 W (1.76 kW).
UPS will require support for different types of load devices, which may have nonlinearity
Input level.
The compatibility between UPS output stages (i.e. inverters) and different types of nonlinear load devices is usually described in the product documentation. Please note that:
In the case of surge current or peak current (such as motor load), even the specified UPS output range cannot provide sufficient details to determine whether the UPS can support the load.
For static loads, UPS specifications can be used to determine compliance.
