IEC 61000-4-29:2000 pdf download

IEC 61000-4-29:2000 pdf download.Electromagnetic compatibility (EMC)-Part 4-29:Testing and measurement techniques -Voltage dips, short interruptions and voltage variations on d.c. input power port immunity tests.
4 General
The operation of electrical or electronic equipment may be affected by voltage dips, short Interruptions or voltage variations of the power supply.
Voltage dips and short interruptions are mainly caused by faults in the dc distribution system, or by sudden lar9e changes of load. Is also possible for two or more consecutive dips or interruptions to occur.
Faults in the d.c. distribution system may Inject transient overvoltages Into the distribution network, this particular phenomenon is not covered by this standard.
Voltage interruptions are primarily caused by the switching of mechanical relays when changing from one source to another (e.g. from generator set to battery).
During a short Interruption, the d.c. supply network may present either a hlgh impedance or low impedance condition. The first condition can be due to switching from one source to another: the second condition can be due to the clearing of an overload or fault condition on the supply bus. The latter can cause reverse current (negative peak inrush current) from the load
These phenomena are random in nature and can be characterised in terms of the deviation from the rated voltage, and duration. Voltage dips and short Interruptions are not always abrupt.
The primary cause of voltage variations is the discharging and recharging of battery systems; however they are also created when there are significant changes to the load condition of the d.c. network,
5 Test levels
The rated voltage for the equipment CUr) shall be used, as a reference for the specification of the voltage test level.
The following shall be applied for equipment with a rated voltage range:
— it the voltage range does not exceed 20 % of its own lower limit, a single voltage from the range may be used as a basis for test level specification (Ur);
— in all other cases, the test procedure shall be applied for both the lower and upper limits of the rated voltage range.
The following voltage test levels (in % Jr) are used:
— 0 %. corresponding to interruptions;
— 40 % and 70 %, corresponding to 60 $ and 30 % dips:
80 % and 120 %, corresponding to ±20 % variations.
The change of the voltage is abrupt, In the range of ps (see generator specification in clause 6).
The preferred test levels and durations are given in tables la, lb and ic, The levels and durations shall be selected by the product committee.
6 Test generator
The following features are common to the generator for voLtage dips, short interruptions and voltage variations, except where otherwise indicated.
The generator shall have provisions to prevent the emission of disturbances which may influence the test results.
Examples of generators are given in figure Al (test generator based on two power sources with internal switching) and figure A.2 (test generator based on a programmable power supply).
6.1 Characteristics and performances of the generator
The test generator shall be able to operate in continuous mode with the following main specifications:
— Output voltage range (U0): up to 360 V
— Short interruptions, dips, and variations of the
output voltage: as given in tables la, lb and ic
— Output voltage variation with the load (0 to
rated current): less than 5 $
— Ripple content: less than 1% of the output voltage
— Rise and fall time of the voltage change.
generator loaded with 100 Q resistive load: between I ts and 50 is
— Overshootundershoot of the output voltage.
generator loaded with 100 fl resistive load: less than 10 % of the change in voltage
— Output current (steady state) (Ia): up to 25 A
The use of a generator with higher or lower voltagecurrent capability is allowed provided that the other specifications (Output voltage variation with the load, rise and tall time of the voltage change, etc.) are preserved. The test generator steady state power/current capability shall be at least 20 % greater than the EUT powercurrent ratings
The test generator, during the generation of short interruptions, shall be able to:
— operate in low impedartce condition, absorbing inrush current from the load (it any). or
– operate in “high mpedance condition, blocking reverse current from the load.
The test generator, during the generation of voltage dips and voltage variations, shall operate in low impedance” condition.