Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Distributed generation

Impact of Distributed Generation on a Distribution Network Voltage Sags in Baghdad City

Ali H. Mohammed; Suad I. Shahl

Engineering and Technology Journal, 2021, Volume 39, Issue 4A, Pages 528-542
DOI: 10.30684/etj.v39i4A.1828

Voltage sags are considered as one of the most detrimental power quality (PQ) disturbance due to their costly influence on sensitive loads. This paper investigates the voltage sag mitigation in distribution network following the occurrence of a fault. Two software are used in this work; the 1st is MATLAB R2017a for implementation of the Differential Evaluation (DE) algorithm to find the optimal location and size DG and while the 2nd software is CYME 7.1 for the distribution system modelling and analysis. The effectiveness of the proposed method is tested by implementing it on IEEE 33-bus system, and then it is applied to Al-Masbh distribution network in Baghdad city as a case study. The paper aims to enhance voltage profile, power loss reduction, and relieve distribution lines overloading, by optimal placement of distributed generation (DG). The results indicate the efficiency of the proposed method comparing with Real Coded Genetic Algorithm (RCGA).

Optimal Reconfiguration and Distributed Generation placement in Baghdad Distribution Sector

Inaam I. Ibrahim Ali; Omar Y. Saeed

Engineering and Technology Journal, 2018, Volume 36, Issue 3A, Pages 333-343
DOI: 10.30684/etj.36.3A.13

The power losses in distribution system are high, which form 70 – 80% of total transmission and distribution losses. High losses have severe impact on stability, reliability as well as economy. Therefore, minimization of these losses is very necessary. In this paper proposed various schemes to reduce the active power losses in distribution network, given as:
- Optimum reconfiguration network,
- Optimum Distributed Generation (DG) placement and
- Optimum reconfiguration with optimum (DG) placement.
Using Cymdist software to implement the optimal reconfiguration algorithm and proposed Genetic Algorithm (GA) to find the size and location, which programmed under MATLAB software package. Whereon the proposed methodology (GA) simplifies the problem by dividing it in two phases, namely Placement Planning Model (PPM) and Size Planning Model (SPM) thereby reducing the search space. It was the integration of the two methods were used after each method individually to obtain minimum real power losses with better bus voltage (better efficiency for network).To verify the proposed algorithms, IEEE 33-bus system and al – jihad neighborhood distribution system (Baghdad distribution sector) are tested. The simulation results are compared with proposed works in literature.

Protection Coordination with Distributed Generation in Electrical System of Iraqi Distribution Grid

Rashid H. Al-Rubayi; Ammar Abbas Majeed

Engineering and Technology Journal, 2016, Volume 34, Issue 6, Pages 1161-1181

The nature characteristic in conventional distribution networks is radial by single source supplying a downstream network. The interest about the environmental impacts and development in technologies have led to increase distributed generation (DG) interconnected in distribution networks. Protective device coordination will be affected by adding DGs to the existing network through participating to the change in direction of power flow and fault current values and direction which cause loss in settings and mis-coordination for protective devices, especially over current relays.
The effect of DG on coordination depend upon number, location and size of DG, so in this work, the Particle Swarm Optimization (PSO) technicality utilization to locate optimal location and sizeof DG to obtain minimum active power losses.The Time Current Characteristic (TCC) curves represented which depended on the over current protection relays parameters to find settings and limited any loss in it, in order to reset these relays to obtained the proper operation without intersections in time of operation and satisfy optimal coordination between primary and pack up over current protection relays.
In this work two soft wares are used, the first is Matlab R2014a for implementation of the PSO algorithm while the second software is CYMDist program for load flow analysis, short circuit current calculation and protection coordination device analysis. To verify the developed algorithm parts from Iraqi distribution network (Baghdad Al-Rusafa 33KV distribution networks). So, used two DG units with total capacity 50MW distributed in 33kV of South Al-Rusafa distribution network which represented about 9.4% from the total load of this network 533.5MW, the total active power losses reduced from 11.597MW to 6.658MW with losses reduction 6.96MW about 43% from total losses.

Reducing the Impacts of Distributed Generation in Transmission & Distribution Networks Protection Using Fault Current Limiters

Wafaa Saeed

Engineering and Technology Journal, 2013, Volume 31, Issue 12, Pages 2273-2291

Increase in power generation capacity of electric power systems has lead to
increase in the fault current level. In some cases fault current levels are exceeding the
interrupting capability of existing transmission and distribution substations circuit
breakers. Since short-circuit currents contain extremely high energy and can damage
electrical equipment, either requires the replacement of a large number of existing
substation breakers with higher rating breakers or the development of some means to
limit fault current. Different technologies have been employed to design Fault Current
Limiters FCLs such as turn-off a solid state switch to using superconductors that
respond with increasing resistance in event of fault current. A proper design of
Modular Level Based Solid-State Fault Current Limiters is proposed in this paper,
describes the functioning of FCL and the amount of impedance they are required to
insert in series with transmission or distribution substation are discuses. This will
allow near instantaneous breaking of bus ties in transmission and distribution
substations to reduce the available short circuit current and allow existing circuit
breakers to clear at lower fault current levels. Since FCL's are installed in each phase
of the line, the fault is viewed in perspective of per phase. For the purposes of this
study, we consider phase to ground fault& phase to phase fault scenarios.

Optimal Size and Location of Distributed Generators using Intelligent Techniques

Rashid H. Al-Rubayi; AzharM. Alrawi

Engineering and Technology Journal, 2010, Volume 28, Issue 23, Pages 6623-6633

One of the modern and important techniques in electrical distribution
systems is to solve the networks problem of service availability, high loss and low voltage stability by accommodating small scaled de-centralized generating units in these networks, which is known as distributed generation (DG). The Genetic Algorithm (GA) technique is dedicated in this work to find the optimal DG locations, and then optimally allocate units in order to maximize the penetration
level, minimize loss, and improve voltage stability