digital signal processing assignment

8/9/2019 Digital Signal Processing Assignment

1/5

DIGITAL SIGNAL

PROCESSING

SECTION: D

FALL SEMESTER 2014

Instructor:

Sir Muhammad Omr

Studnts:

Muhammad Fai!an Faroo"

EE#00$Su%mission Dat: 24th

Octo%r&2014


2/5

On#'in Idnti(cation o) *o+r S,stm Osci''ation

Mods -, .sin/ Ra' Tim FFT

*ro%'m Statmnt:Owing to the increasing size and complexity of electric power systems, and also owing to the

high rate of growth of electric power demand. electric power systems are being operated in a

more stressed state and a lower stability margin, therefore, real time stability monitoring is

becoming more important for the reliable power system operation.instability is monitored,

then preventive control actions are required to keep the system stable and also to continue theuninterruptible power supply.

So'ution:This paper presents a real time FFT based online identification of oscillation modes in electric

power systems to evaluate the stability of power systems in real time. The monitoring system isset up by using a personal computer with a DSPboard, which hasAD and DA conversion

interfaces.

For the identification of oscillation modes, the real power flow signal is utilized. The real powersignal is sampled onto the memory on the !"# board through the $! conversion interface and a

sequence of stored real power signal is utilized for the FFT analysis in real time on the !"#board.. The FFT result is passed to the workspace in the %atlab&"imulink environment for thevisualization of the FFT result using a color mapping to show the variation of oscillation modes

in real time. Furthermore, a fuzzy reasoning based decomposition of individual modes has been

proposed to identify individual mode of oscillations included in the measured real power signals.

The efficiency of the proposed method has been demonstrated through the testing using testsignals with multimode of oscillations and also through the celesting using monitored signals in

transient stability simulations on the $nalog #ower "ystem "imulator.

R)rnc:Takashi Hiyama, Senior member Nacoto Suzuki Takahiko Funakoshi, On-line

!entification of Po"er System Oscillation #o!es $y %sin& 'eal Time FFT(


3/5

F*A Ra'i!ation o) Racti *o+r Masurmnt

S,stm -asd on FFT

*ro%'m Statmnt:

'hen power system is running, the energy supplied by power grids has two parts. One is active

power, which is used for unidirectional conversion of the energy. The other is reactive power,which is used for energy exchange between electric field and magnetic field in circuits and do

not act outside. (ut reactive power is very important to normal operation of power supply

systems and the load. )t can cause voltage loss and power loss when flows in power grids.Therefore, we must measure the size of reactive power that power consumers absorb from power

grids and is transmitted by power grids.

So'ution:

FFT is a kind of algorithms of reactive power measurement. )t has high measurement precisionand can be easily implemented on hardware. *ow it is widely used in reactive power

measurement. F#+$ model of reactive power measurement based on FFT is put forward in thispaper. Two ways to achieve FFT results are designed in this paper. One way is to use FFT )# core

provided by $ltera ompany, and the other way is to design FFT by ourselves with programs.

The system is implemented on -#/0 series F#+$ chips of $ltera ompany."ome characteristics of the system such as precision, speed and resource consumption are

analyzed in details.

R)rnc:Huimei )uan , #in&ke $i , *on&yin& +hen, FPA 'ealization of 'eactie Po"er

#easurement System $ase! on FFT(


4/5

Rsarch and dsi/n o) di/ita' o+r "ua'it,

ana',sis s,stm %asd on mi3d radi3 FFT

*ro%'m Statmnt:

-lectric energy is widely applied in people1s daily life and the industry production since it2sclean, cheap, easy to transport, easy to control and easy to convert . 'ith the development of the

national economy and science, people2s requirement in the quality of electric energy of the power

system becomes more and more because of the application of the hightech products. Thetechnical innovation and the wide use of nonlinear loads bring a lot of unstable factors to power

system, which can make a drop in the quality of electric energy of the power system. )n order to

meet people2s increasing demand of electric energy, the state2s twelfth Five3ear #lan putforward developing smart grid clearly. Therefore, realtime monitoring of the grid power quality

has a great significance in analyzing and improving the quality of electric energy of the power

system, and also has a great significance in preventing the wrong action of the smart gridduring the power transmission and distribution.

4sually, power quality refers to the quality of alternating current from power supply end toelectroreceiving end in the power system. $nd the main indicators used to evaluate the

power quality contain rootmeansquare 56%"7 value of voltage, 6%" value of current, activepower, reactive power, apparent power, power factor, voltage deviation, frequency deviation,

threephase unbalance degree, harmonics of public power system, fluctuations and flicker of

voltage, temporarily overvoltage and transient overvoltage.

So'ution:$ hardware detection method for frequency measurement and a digital harmonic analysis method

based on mixed radix FFT for the measurement of harmonics, and adopts a frequencydomainanalysis method based on mixed radix FFT to measure the fluctuations and flicker of voltage.

ompared with other measuring methods, the methods proposed in this paper are simpler andmore reliable with fewer complex mathematical calculations and a better realtime performance.Finally, a realtime digital power quality analysis system was designed and implemented in the

laboratory by using $6% processor and mixed radix FFT algorithm. The system designed was

tested in the laboratory, and the testing result satisfied the requirement of )-89000:;0standard .

$s the $6% processor is not good at floatingpoint calculation, in the future research, we can

design a special hardware platform for the digital analysis system of power quality by using$6% processor and !"# processor.

R)rnc:)in .in, *han& Aimin, *han& Han&, Hao /i0ia,'esearch an! !esi&n of !i&ital 1o"er2uality analysis system base! on mi0e! ra!i0 FFT(


5/5

A'ication o) DFT and FFT A'/orithms to Sctra'

Ana',sis o) *o+r S,stm Load ariation

*ro%'m Statmnt:#ower consumption is not constant. )t varies according to people1s changing demands. The

variation is periodic with respect to the hour, the day and the time of the year. The problem is to

identify the predominant components of this variation for use in analysis and prediction. The

load demand is usually measured and recorded every hour. This results in : samples per day.

So'ution:

digital signal processing assignment

Documents