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| PDSH 998
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1 N; \2 u# p( A1 w @1 T( L5 @9 N | Measurement of circuit power factor and supply current
4 {$ _/ I) {4 H4 m' C | General, N5 ^5 ]( s, b0 d/ S4 G+ z% V4 Q6 Q
| 60968(ed.1);am1;am2 & 60969(ed.1);am1;am24 l0 q/ ~6 Q! ~2 `* N2 }& s; u- Z
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4 h, {/ P; F1 B% f+ v9 y5 GStandard(s):
b0 H- C D1 M' oIEC 60968 All editions3 ]4 {' I S8 G! N3 e! y8 K
IEC 60969 All editions3 ?# F) F! { ^) s+ F4 A
Subclause(s): General
, W/ G& i: a! y% g" dNo. Year PDSH 0998 20104 [1 N- L j4 ~5 V9 M, x
Category: LITE
: `$ x! l @1 f. E, i; VDeveloped by: ETF5 OSM/LUM. |' N4 s1 T7 S
Subject: k# s9 G& p( y; W7 l! `" z; z/ w
Measurement of circuit power factor and supply current
+ w' U O/ l8 c7 T' B3 HKey words:
3 }6 E6 E9 m+ P/ q- True power factor2 T1 n0 I: T+ L) r
- Supply current
6 R" ^) \" K* r4 H0 y; \+ p# R- High frequency components& w/ ?$ R& q6 x- P X
To be approved at the 49th CTL Plenary Meeting, in 2012
, ]$ B/ W1 L- _1 }; T) dQuestion:
8 g+ Z4 n, b& ]* O# CWhen measuring the circuit power factor and supply current of non linear load (a self-ballasted lamp), we
4 q* Q# `1 a. s$ p- bwould like to check if there is a need to consider the frequency range of the power meter. The product in% v3 q6 s7 K' ?, q) o0 J
question produced high frequency components as shown in Figure 1. The true power factor can only be" O+ X; B7 U- _' C) k
measured with power meter set to encompass these high frequencies. With the power meter’s frequency range+ D, a" [! t, O% t0 u* `
specified from d.c. to 25 KHz, the power meter reads a power factor of 0,880 and a current of 330 mA. As the
5 ?2 O i6 ]4 W5 \( n1 ]; Q& P1 D+ `frequency range was extended to 50 KHz, we found the power factor is much lower compared with cos f& s) b3 ?5 Y8 }6 W+ r- x
(power factor measured at fundamental frequency). Which value of power factor can we accept on the product
, ^5 t3 D$ B5 g$ c9 A$ ?or on the manufacturer catalogue?" L3 e$ C: w! V! Q2 {/ g: Y
Decision:4 H7 g0 e( @; s* T
In case of high harmonics and high crest factor, to get an accurate measurement, a power meter with a higher! r4 C7 c2 x% V
frequency range has to be used.5 | @+ J% S7 A1 _; @
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