**8. Study proceedures and results**

#### **8.1 Introduction**

The University consists consists of 60 buildings including students housing. Almost each student at the university has a laptop regardless of the number of PC's in each, laboratories, or rooms. The university in-house that there are around 6000 PCs distributed unequally . Most of the PS's in the university are of model HP, DELL, Compaq dc 7800P; they use Intel core 2 Dual processors.

#### **8.2 Measurement plan**

This investigation adapted the following steps which include:

Obtaining all line diagrams of the area of investigation.

Harmonics Effect in Industrial and University Environments 223

The measurements have been conducted by the team members of the project according to

**Reading #3 period** 

1:30PM 1:40PM-4:00PM At point 1\*

1:30PM 1:40PM-4:00PM At point 2\*\*

1:30PM 1:40PM-4:00PM At point 3\*\*\*

**location inside the substation** 

**Reading #2 period** 

12:10Pm-

12:10Pm-

12:10Pm-

At the first point shown in the single line diagram (Figure 4), three measurements have been

The measurement of the harmonics caused by PC's and any other nonlinear elements were

At the first point shown in the single line diagram (Figure 4), three measurements have been conducted over three periods. The THD during the first period at point one was measured and the maximum total harmonic distortion (THD) was 10.6%. The THD during the second period at point one and the maximum total harmonic distortion (THD) was 10.7%. The THD during the third period at point one and the maximum total harmonic distortion (THD) is

From the previous three readings it is clear that at normal load at point one the maximum total harmonic distortion of the three readings is 10.8%. Moreover, the harmonics effect

For the second point the THD during the first period indicated a maximum total harmonic

On the second measuring period the THD during the second period at point one and the maximum total harmonic distortion (THD) was 28.4%. The THD during the third time period at point two indicated maximum total harmonic distortion (THD) of 28.9%. From the previous three readings it is clear that at normal load at point two increases the harmonic flow, the maximum total harmonic distortion of the three readings is 28.9%. Moreover, the

harmonics appears to distort the phase current waveform as in Figure 6.

conducted at each bus (points 1, 2, and 3) as indicated in the single line diagram.

**8.3 Measurements at normal load** 

**Day Reading #1** 

Monday 9:00AM-

Tuesday 9:00AM-

Wednesday 9:00AM-

Table 5. Time table of measurements

**8.4 Measurements and results** 

distortion (THD) was 29%.

10.8%

**period** 

12:00Pm

12:00Pm

12:00Pm

\*indicates the point between MPD2 &the transformer 380/208 v \*\*indicates the point between UPS &the transformer 480/380 v \*\*\*indicates the point between EPDP & the main feeder 3ф-4w 480v

conducted over the three periods as listed in table 5.

appears in the current waveform as in Figure 5.

the following time Table:


To conduct harmonic measurement the team members attended intensive lectures and training on Power Quality and measurements. Training focused on how to use the power quality analyzer (PQA).

Single line diagrams for each of the building under investigate were obtained as shown in Figure 4. Permissions to conduct measurement and open switch boards of the different feeders were also obtained through the university Electrical Maintenance department.

The whole Excl file containing total PC's provided by from ITC indicating all the university PC's record and their distributions at the different building and labs etc…The total February 2009 PC's numbers was 6,344.00.

Fig. 4. Building 14 Single Line Diagram and Points of Measurements and switch boards
