Considerations on the non-active power using geometric algebra
Abstract
Several approaches have been developed to define the non-active power concept under nonsinusoidal situations in electrical systems. Nevertheless, these contributions do not provide a complete and satisfactory solution to the non-active power reversibility between frequency domain and time domain. This paper presents a non-active power multivector concept, based on an original vector space frequency-domain approach that bridges the gap between both domains. The suggested correspondence can provide a convenient descriptive language to reconcile Fryze’s instantaneous non-active power with Budeanu´s deactive-power.
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Seediscussions,s a s,andau ho p o iles o hispublica iona :h ps://www. esea chga e.ne /publica ion/252049908
Conside a ionson henon-ac i epowe using
geome icalgeb a
A icle·May2011
DOI:10.1109/Powe Eng.2011.6036438
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1
Conside a ions on he Non-Ac i e Powe Using
Geome ic Algeb a
M. Cas illa, Membe IEEE, J. C. B a o, J. C. Mon año, Senio Membe IEEE,
M. O dóñez and A. López.
Abs ac —Se e al app oaches ha e been de eloped o de ine
he non-ac i e powe concep unde nonsinusoidal si ua ions in
elec ical sys ems. Ne e heless, hese con ibu ions do no
p o ide a comple e and sa is ac o y solu ion o he non-ac i e
powe e e sibili y be ween equency domain and ime domain.
This pape p esen s a non-ac i e powe mul i ec o concep ,
based on an o iginal ec o space equency-domain app oach
ha b idges he gap be ween bo h domains. The sugges ed
co espondence can p o ide a con enien desc ip i e language o
econcile F yze’s ins an aneous non-ac i e powe wi h Budeanu´s
deac i e-powe . To cla i y his co espondence, a basis example
is conside ed.
Index Te ms—Non-ac i e powe , appa en powe ,
ins an aneous powe , mul i ec o , geome ic algeb a.
I. INTRODUCTION
A. Mo i a ion
ne o he mos con o e sial issues in elec ical
enginee ing is he uni e sal ep esen a ion o he powe
equa ion o he elec ical ci cui s in n-sinusoidal ope a ion.
Thus, while he concep o ac i e powe is ully accep ed, he
de ini ion o powe ela ed o “ eac i e” and “ha monic”
phenomena is s ill unde discussion. This is o absolu e
impo ance, since i is he ounda ion o he non-ac i e powe
concep ha pe mi s he design o sui able de ices o he
compensa ion o his powe componen . This pape gi es a
new ision on he ep esen a ion o he non-ac i e powe (
Σ
)
and sugges s a mul i ec o ial in e p e a ion in a simple ci cui
wi h n-sinusoidal wa e o ms. F om a heo e ical s andpoin ,
he app oach p esen ed he e di e s om he equency
domain app oaches desc ibed in he li e a u e by i s emphasis
on complex Geome ic Algeb a
(
. In his amewo k, he
non-ac i e powe is ep esen ed by a mul i ec o ha egis e s
i s magni ude, di ec ion and sense. Mo eo e , in o de o
examine he ecip oci y be ween equency-domain and ime-
domain, he e a e some doub s which should be cla i ied. A
igo ous ea men o his issue can lead o new a enues and
pe spec i es in powe heo y.
)
n
CG
This wo k was suppo ed by he Minis y o Educa ion and Science as pa
o a esea ch h ough p ojec DPI-2006-17467-CO2-01.
M. Cas illa and J. C. B a o a e wi h he Elec ical Enginee ing Depa men
o he Uni e si y o Se illa, C/Vi gen de Á ica 7, (41011) - Se illa, Spain.
(phone:+34 954 55 28 47; ax: +34 954 55 16 88; e-mail: [email p o ec ed];
[email p o ec ed]).
J. C. Mon año is wi h he Spanish Resea ch Council (CSIC), Reina
Me cedes Campus, POB 1052, 41080-Se illa, Spain. (email:
mon ano@i nas.csic.es).
M. O dóñez is wi h he Depa men o Applied Ma hema ics II. Escuela,
Poli écnica Supe io , Se illa, Spain. (e-mail:m[email p o ec ed]).
A. López is wi h he Depa men o Elec onic Technology, Escuela
Poli écnica Supe io , Se illa, Spain. (email: [email p o ec ed]).
B. Li e a u e e iew
Budeanu and F yze o mula ed he i s powe equa ions o
n-sinusoidal ope a ion be ween 1920 and 1930. The o me ,
[1], add essed he ques ion in he equency domain, whils
he la e , [2], add essed he p oblem in he ime domain.
Mo i a ed by hese heo ies, nume ous aluable a icles
ha e appea ed [3-13] al hough none conside s he
mul i ec o ial cha ac e o appa en powe componen s.
On he o he hand, he mul idimensionali y o he powe in
n-sinusoidal ope a ion sys ems is he unde lying obs acle ha
complica es he p oblem a hand. The powe concep is be e
unde s ood i a ec o space is used o ep esen a ion o he
powe equa ion. In his sense [14], [15] a e wo impo an and
o iginal con ibu ions o he powe analysis in linea /non-
linea ope a ion. The la ge numbe o pape s published on he
physical and/o ma hema ical na u e o hese e e sibili y,
sugges s ha wo k on his opic emains un inished.
C. Con ibu ions
The one- o-one co espondence be ween he non-ac i e
mul i ec o e ms and he ins an aneous powe componen s
a e conside ed and cla i ied. These objec i es canno be
eached in a Complex Algeb a amewo k.
II. NON-ACTIVE POWER MULTIVECTOR
Suppose ha a nonsinusoidal ol age
(
)
()
p
p
pN
u 2 U sinp
ω
α
∈
=+
∑
(1)
is applied o a linea load, Fig.1, whe e p is he ha monic
o de o u( ). The esul ing cu en has an ins an aneous alue
gi en by
(
)
(
q
qN
i 2 Isinq
)
q
ω
β
∈
=+
∑
(2)
whe e q is he ha monic o de o i( ). Fo cla i y o
p esen a ion and wi hou loss o gene ali y, he phases angles
o he ha monic ol ages a e .
p
α=0
By applying he Cli o d-Fou ie ans o m [15] o he
O
P oceedings o he 2011 In e na ional Con e ence on Powe Enginee ing, Ene gy and Elec ical D i es
To emolinos (Málaga), Spain. May 2011
978-1-4244-9843-7/11/$26.00 ©2011 IEEE
2
ol age (1) and cu en (2), he ins an aneous quan i ies can be
exp essed as a linea combina ion o ha monic geome ic
phaso s o complex- ec o s in
n
CG
()
() 2 sin
p
pp
pp
u U p U U
ω
σ
=⇒=
∑∑
(3)
()
()
2sin q
j
qq q
qq
i I q I Ie
ϕ
q
ωϕ
σ
=+⇒=
∑∑
(4)
In his amewo k, he powe mul i ec o [15]
en e ing he one-po in Fig. 1, is
n
CG S
N
SU I UI UI
•∧
∗∗
ΩΩ
⎧⎫
⎪
==⋅⊕∧
⎨
⎪⎪
⎩⎭
:
∗
⎪
⎬
(5)
whe e pp
pN
UU
σ
∈
=∑
and q
j
q
qN
IIe
ϕ
q
σ
∗
∈
=∑
a e he
geome ic phaso s o ol age and conjuga e cu en
espec i ely. In he expanded o m o (5), he wo componen s
(scala complex) and (bi ec o complex) can be
exp essed
•
Ω
∧
Ω
{
}
{
}
0
00
Re Im ( cos sin )
()()
pp p pp p
P
pp
P
jUIjUI
PjQ PjQ
ϕ
ϕσ
σσ
•• •
Ω= Ω + Ω = +
=+ =+
∑
∑
(6)
(
q
j
p q pq pq pq pq
pq pq
UI e j
ϕ
)
σ
σ
∧
≠≠
Ω= = Δ +Λ
∑∑
(7)
whe e
{}
Re Ω•
is he ac i e powe P and
{
}
Im Ω•
is
associa ed o Budeanu and Slonim’s eac i e powe Q.
Combining (6) and (7), we ob ain he non-ac i e powe
mul i ec o ha is de ined as
Σ
(
•
)
p
qpq
pq
Im + j pq
σ
≠
⎡⎤
ΣΩ Δ+Λ
⎣⎦
∑
= (8)
whe e he e ms ep esen s he in e ac ion o
ol age and cu en ha monics wi h di e en equencies. The
sugges ed ep esen a ion
(
pq pq
jΔ+Λ
)
(8) can be ex ended in a
s aigh o wa d manne o he exis ing powe equa ions in he
equency domain. In his way, he mul i ec o enables
sepa a e ea men o he smalles non-ac i e powe e m
which conside s only he undamen al componen , Emanuel
app oach [11], and he la ges one which includes he
imagina y pa o he complex scala and he o al complex
bi ec o , F yze app oach [2]. I is ema kable ha he
quan i ies p oposed in
Σ
(5) ha e h ee basic a ibu es:
magni ude, di ec ion and sense.
III. POWERS IN FREQUENCY-DOMAIN AND TIME -DOMAIN
The inne o scala p oduc in (5) is symme ic bu , on he
o he hand, he ou e p oduc is an isymme ic
(
)
p
qqp
σσ
=− .
Thus he appa en powe (5) and i s no m can be exp essed as
(
)( )
(
)
ΔΔ ΛΛ
p
p 0 pq qp pq qp pq
Ppq
S(PjQ) j
σ
σ
≠
=+ + −+−
∑∑
(9)
()(
ΔΔ ΛΛ
22
222
pq qp pq qp
pq pq
SPQ
≠≠
)
⎡
⎤⎡ ⎤
=++ − + −
⎢
⎥⎢ ⎥
⎣
⎦⎣ ⎦
∑∑
(10)
and he non-ac i e powe mul i ec o is now
Load
i( )
u( )
+
Fig. 1. Linea load wi h n-sinusoidal wa e o ms
(
)( )
(
)
ΔΔ ΛΛ
p
0pqqppqqp
Ppq
Scala pa Bi ec o pa
Σ=j Q + j pq
σ
σ
≠
−+ −
∑∑
(11)
which a e exp essed as a linea combina ion o he mul i ec o
basis.
In ime domain, he ins an aneous powe
s
( ) en e ing he
gene ic ci cui o Fig.1 is gi en by
s
( )= u( )i( ) (12)
Now i is seen om (3),(4) and (12) ha i may be w i en in
he o m
()
()()
()()
()
()()
p
2
p
sin
sin sin cos
cos sin sin
sin sin cos
p
p
p
pq
pq
pq
pp p
pp p
pq q
pq q
P
p( )
Q
q( )
p( )
s( )= U I cos 2 pω
UI 2 pω pω
+U I 2 pω qω
UI 2 pω qω
Δ
Λ
⎡⎤
ϕ⎣⎦
−ϕ
⎡
⎤
⎣
⎦
ϕ
⎡
⎤
⎣
⎦
−ϕ⎡
⎣
∑
pq
q( )
⎤
⎦
(13)
whe e is he ins an aneous ha monic ac i e powe e m,
is he ins an aneous ha monic eac i e powe e m,
and and a e he ins an aneous c oss-
ha monic powe e ms. This analysis can eadily be ex ended
o mo e gene al si ua ions in ol ing any numbe o ha monic
componen s, as long as he sui able
p
p( )
p
q( )
pq
p( ) pq
q( )
n
CG s uc u e is chosen.
The e o e, (13) consis o wo pa s, whe e he i s pa
con ains a g oup o ins an aneous powe e ms in ol ing like-
equency and he second pa con ains hose in ol ing c oss-
equency. Then, he o al ins an aneous powe
s
( ) , (13), can
be seen as o med by wo powe componen s, ac i e ,
and non ac i e , gi en by
a
p( )
na
p( )
p( (14)
a
p
p
)= p( )
∑
na p pq pq
ppqpq
p( )= q( ) p q( )
≠≠
++
∑
∑∑ (15)
In (9), each coe icien
p
ppqpqqpqp
P,Q, , , ,ΔΛΔΛo a
co esponding mul i ec o is a he same ime a p opo ional
ms alue o a co esponding ins an aneous powe (13).
In ac , he equa ion (13) gene a es he keys one o he
3
b idge be ween he magni udes in equency domain and hei
associa ed oscilla ions in ime domain. Thus, he classic
appa en powe and non-ac i e powe alues can also be
in e p e ed in e ms o Cli o d coe icien s and no ms o
co esponding oscilla ing componen s
222
p p pq pq
p=q p=q p q p q
2
S S= p( )+2 q( )+ p( ) q( )
3≠≠
=+
∑∑∑∑
2
(16)
222
Σ=S -P
(17)
No e ha he abo e men ioned powe mul i ec o s, and
a e he complemen s o he me ely alues
S
Σ
SS= and
Σ= Σ
. Bo h quan i ies (mul i ec o and magni ude) lead o
alid powe equa ion ep esen a ion, bu i depends on he
si ua ion a hand o see which app oach is mo e app op ia e.
Fu he mo e, in mos cases di ec ion and sense may no be
equi ed, bu e en in his case, he mul i ec o can handle he
p oblems equally o e en be e han he magni ude S
.
Howe e , he e a e cases whe e di ec ion and sense a e
necessa y, whe eby ailing o dis inguish he powe
componen s in e ms o di ec ion and sense may lead o
e oneous esul s. The e o e, he Gene alized Geome ic
Algeb a [15] p o ides he necessa y ools o ex end he
concep s o ins an aneous and complex geome ic analysis o
highe dimensions.
IV. NUMERICAL EXAMPLE
In his Sec ion, a nume ical example is p oposed o
illus a e he sugges ed non-ac i e mul i ec o concep and i s
na u al capabili y o a one o one co espondence be ween i s
componen s and he e ms o ins an aneous non- ac i e powe .
Uni s o physical quan i ies a e hose s anda ds o he MKSA
sys em and hus can be omi ed.
Le ol age and cu en o a non-linea one-po ci cui be
()
u( ) 2 100sin 100sin 3 =+
⎡⎤
⎣⎦
(18)
i( ) 2 50 2 sin( 45º) 50 2 sin(3 )
⎡
=−−
⎣⎤
⎦
(19)
and he co esponding geome ic phaso s a e hen
13
100 50 111.8UU
σσ
=+ ⇒=
(20)
45 180
13
70.71 20 73.48
jj
Iee I
σσ
∗=+⇒=
⎤
⎦
ω
⎣
)
(21)
The ins an aneous powe equa ion and he appa en powe
mul i ec o may be w i en
P
() ( ) ( )
( ) () () ( ) () ( )
() ()()
3
1
13
13
1
113
31
3
P
P
22
p ( ) p ( )
Q
q( ) p ( )
p
s( ) 5000 2sin 1000 2sin 3
5000 2sin cos 2000 2sin sin 3
2500 2sin 3 sin
Δ
Δ
⎡⎤⎡ ⎤
=ω+− ω+
⎣⎦⎣ ⎦
− ω ω+− ω ω+⎡⎤⎡
⎣⎦⎣
+ωω
⎡⎤
⎣⎦
() ()()
31
131
( ) q ( )
2500 2sin 3 cos
Λ
−ω
⎡⎤
⎦
(22)
()()(
13 1 3 31
03
5000 1000 5000 0 4500 2500
PP P QQ Q
Sj j
1
σ
σ
∧
=+ =+ Ω
⎡⎤
⎢⎥
=−++++
⎢⎥
⎣⎦
(23)
and he con en ional appa en powe is gi en by
S S 8216==
The o al ins an aneous powe is gi en by (22) and i s
wa e o m is depic ed in Fig.2
Acco ding o (14) and (15) he ins an aneous ac i e and
0 3.14 6.28
7899.08
2202.02
s ()
ω ⋅
Fig.2. To al ins an aneous powe s( )
non-ac i e powe s a e gi en by
a13
p ( )= p ( )+ p ( ) (24)
na 1 13 31 31
p ( )= q ( )+ p ( )+ p ( )+q ( ) (25)
0 3.14 6.28
8447.45
265.83
8979.1
pa ()
pna ()
ω ⋅
Fig.3. Ac i e (pa( )) and non-ac i e (pn( )) ins an aneous powe s
and hese wa e o ms a e shown in Fig.3.
Ob iously, (22) and (23) can egis e he bidi ec ional ac i e
powe low occu ing in his case ( ) and o al
ac i e powe is 5
31000P=−
000 1000 4000
−
=. This alue coincides
wi h he a e age powe o (22).
Mo eo e , equa ion (22) also e eals a non ac i e e m
( ) ()()( ) ()()
() ( )
13 31
13 31
p ( ) p ( )
2000 2sin sin 3 2500 2sin 3 sin
500 2sin sin 3
ΔΔ
−ωω+ ωω
⎡
⎤⎡ ⎤
⎣
⎦⎣
=ωω
⎡⎤
⎣⎦
⎦
(26)
which ampli ude alue is
(
)
2000 2500 500−+ =
VA. This is
no he same alue o ha one deduced om (23), since
13 31 31
2000 2500 4500
σ
σσ
−
+=. Al hough (22) and (23) a e
ma hema ically co ec , he wo e ms ha appea ed in
ins an aneous powe equa ion (22), and , ha e
he same na u e despi e hei opposi e signs. These possible
e oneous esul s om he ins an aneous powe
()
13
p ()
31
p
(22) occu due
4
o he need o in o ma ion conce ning di ec ion and sense o
he componen s.
The non-ac i e mul i ec o e ms (8) a e always applicable
o any powe heo y. Thus, in he Example, he
5000
•
Im Ω=
alue is equal o Budeanu and Slonim’s
eac i e powe . The magni ude Σ= 7176
coincides wi h
F yze’s eac i e powe and he esul gi en by
{} {}
5590
22
•
13
Im Ω+ImΩ=
∧
is he same ha he eac i e powe p oposed by Shephe d [4],
Sha on [5], and Cza necki [9] on linea ope a ion. The
sca e ed powe de ined in [8] coincides wi h
{}
4500
13
Re Ω=
∧
and a he same ime wi h he complemen a y eac i e powe
o Sha on [5] and he ac i e dis o ion o Slonim [6].
Thus, he p oposed ep esen a ion is uni ied and in e nally
consis en wi h exis ing powe equa ions. Howe e , ou
equa ions a e no de i ed om pu ely algeb aic manipula ions
o he appa en powe componen s in equency domain, bu
a he hey a e a consequence o he powe mul i ec o .
Today's accep ed heo ies canno explain he esul s ob ained
he e.
V. CONCLUSION
In his pape , a new concep o he non-ac i e powe
mul i ec o unde pe iodic n-sinusoidal linea /non-linea
ope a ion has been p esen ed. Mo eo e , powe o mulas ha e
been gi en i s in Cli o d equency domain and hen in ime
domain. Fu he , a non-ac i e powe mul i ec o has been
de eloped, which condenses all powe in o ma ion and obeys
he usual conse a ion law [16]. In his sense, i b idges he
gap be ween equency domain and ime domain. The new
non-ac i e powe mul i ec o concep plays a simila ole
o he eac i e powe in he S einme z phaso model o he
sinusoidal case; his mul i ec o ha e a simple and compac
exp ession and can iden i y he mos ele an exis ing powe
equa ions.
Σ
Finally, om o he poin o iew, he sugges ed
ep esen a ion can p o ide a new language o he design o
compensa o ci cui s, and op imiza ion algo i hms. The s udy
o hese applica ions is a ask ha dese es u he esea ch.
LIST OF SYMBOLS
1...k
σ
= basis o Cli o d algeb a
: = geome ic p oduc
ab⋅ = inne p oduc
ab∧ = ou e p oduc o bi ec o
p
Z
,
p
Z
= no m o p- h geome ic-phaso
()
Z
∗
= conjuga e elemen
p
U
= p- h ol age geome ic-phaso
p
I
= p- h cu en geome ic- phaso
S
= powe mul i ec o
()
s
= ins an aneous powe
Σ
= non-ac i e powe mul i ec o
•
Ω
= complex-scala
Ω
∧
= complex-bi ec o
q
ϕ
= q- h impedance phase angle
p
q
Δ
= pq- h
{
}
Re pa o dis o ion powe mul i ec o
pq
Λ
= pq- h
{
}
Im pa o dis o ion powe mul i ec o
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