MIL-STD-704F
3.9 Distortion. AC distortion is the RMS value of the AC waveform exclusive of the fundamental. In a DC system, DC distortion is the RMS value of the alternating voltage component on the DC voltage.
3.10 Distortion factor. The AC distortion factor is the ratio of the AC distortion to the RMS value of the fundamental component. The DC distortion factor is the ratio of the DC distortion to the DC steady state voltage.
3.11 Distortion spectrum. The distortion spectrum quantifies AC or DC distortion in terms of the amplitude of each frequency component. The distortion spectrum includes the components resulting from amplitude and frequency modulation as well as harmonic and non- harmonic components of the waveform.
3.12 Electric starting operation. Electric starting operation is a specialized case of normal electric system operating conditions where the normal voltage limits may be exceeded due to the high electric demand. The voltage limits for normal operation may be exceeded during the following starting conditions:
a. An electric start of the propulsion engine. (Battery power, aircraft DC power or external power applied on the aircraft bus.)
b. A battery start of an auxiliary power unit.
3.13 Emergency operation. Emergency operation occurs following the loss of the main generating equipment when a limited electric source, independent of the main system, is used to power a reduced complement of distribution and utilization equipment selected to maintain flight and personnel safety.
3.14 External power source. The external power source refers to the ground or shipboard power source used to provide power to the aircraft's electrical distribution system.
3.15 Frequency. Frequency is the reciprocal of the period of the AC voltage waveform. The unit of frequency is Hertz (Hz). Steady state frequency is the time average of the frequency over a period not to exceed one second.
3.16 Frequency modulation. Frequency modulation is the difference between the maximum and minimum frequency values that occur in a one-minute period during steady state operating conditions. Frequency modulation is a measure of the stability of the power system's frequency regulation.
3.17 Load unbalance. Load unbalance for a three-phase load is the difference between the highest and lowest phase loads.
3.18 Normal operation. Normal operation occurs when the system is operating as intended in the absence of any fault or malfunction that degrades performance beyond established requirements. It includes all system functions required for aircraft operation except
3
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business