• Energy Research

This paper proposes a new maximum power point tracking (MPPT) algorithm for thermoelectric generators (TEG). The new-presented method is based on implementing an indirect open circuit voltage detection and short circuit current estimation methods, which will be used to directly control the TEG interface power converter, resulting in reaching the maximum power point (MPP) in minimal number of steps. Two modes of operation are used in the proposed algorithm, namely the perturb and observe (P&O) method for fine-tuning and the transient mode for coarse tracking of the MPP during fast changes that occur to the temperature gradient across the structure. A novel voltage sensing technique as well is proposed in this work, to reduce the number of voltage sensors used to control and monitor the power converter. The proposed strategy employs a novel approach to sense two different voltages using the same voltage sensor. The input and output voltage information is collected from an intermediate point in the converter. The reconstructed voltages are used in the control loops as well as for monitoring the battery output or load voltages. Simulation and experimental results are provided to validate the effectiveness of the proposed algorithm and the sensing technique.

Abstract In this research, a new parameter estimation technique for determining the bus admittance matrix (Ybus) is proposed to further calibrate power system models. Ybus estimation is done using recorded PMU synchrophasor measurements. The approach proposed in this research is based on recognizing that bus injection currents Ibus can be viewed as signals produced by a random process. In this manner, the corresponding bus voltages Vbus are also stochastic signals that are related through a cross-covariance matrix to the vector Ibus. Using estimation techniques developed for statistical signal processing, the cross-covariance matrix is shown to be Zbus. Research done previously in this area requires the prior knowledge of the electrical interconnection as well as full availability of PMU measurements. This method does not depend on prior knowledge of the electrical interconnection between the buses. It extracts the electrical interconnection and the parameters of the network model in the form of Ybus. It also does not require full availability of PMU measurements at each bus in the system. It estimates the partial Ybus based on the available PMUs.

Electrical generation in Jordan currently relies on imported fossil fuels. In the past, most imported fossil fuels were subsidised by neighbouring countries through grants and aid. This has led to a regulated market, with subsidised low-cost electrical energy consumers, and the government being the sole buyer and seller of electricity. With the ageing of the national electrical infrastructure, political instability in the region, and lack of funds for direct investment, other options needed to be pursued. Long term Power Purchase Agreements (PPA) were granted to Independent Power Producers (IPP) to encourage investment in capacity and infrastructure. In addition, long-term fuel contracts were signed to secure steady flow of primary fuel sources. Over the past few years, renewable energy penetration has increased rapidly, but without proper planning or taking into consideration long term PPA and fuel contracts. Data in regard to the current infrastructure, renewable energy technology, signed energy commitments and system operation assumptions are described in this article, which may be used for modelling and analysis. The Data were collected from annual reports from the different energy related entities in Jordan.

As global energy consumption continues to increase, increased utilization and adaptation of renewable energy resources have tremendously increased over the last decades. Unfortunately, despite the many benefits of renewable energy resources, the intermittent nature of generation and the far distance of large installations from demand centers have tremendous effects on the connecting grid’s stability. In this study, high-voltage direct current (HVDC) systems are proposed as a solution for stable and reliable grid operation in the presence of large renewable energy installations. This research investigates the deployment of an HVDC system into an entire network rather than studying it as an isolated radial system. Various power system analysis functions for both static and dynamic conditions are used to study the effect of integrating an HVDC system on the overall network’s stability. To verify the proposed approach, Jordan’s national electric grid was modeled and used as a case study. The results show when deploying HVDC transmission, losses are reduced by 70% from the baseline case, in addition to better handling of contingency events and enhanced grid’s stability when examining the generator’s rotor angle and speed. Rigorous modeling and simulations of the proposed system structure show the feasibility and prove the advantages of modern HVDC systems over HVAC counterparts.

Abstract Energy security and independence is one of the most growing concerns around the globe, combined with the environmental impact of traditional energy sources, renewable energy systems have become of great importance. Photovoltaic (PV) systems are the most popular form of renewable energy, as price have become reasonable, and deployment is scalable. However, in many schemes, PV systems require rechargeable batteries for energy storage, and increased system dependability. In this paper a numerical solution and two new control methodologies are proposed for effective battery charging from PV systems. The first method is a modified single stage charge controller with a new maximum power point tracking (MPPT) algorithm. This method uses the battery voltage as a feed-forward term while optimizing the duty cycle of the converter to maximize the output power harvested from the PV cell. The second method is a modified two stage charge controller. The proposed approach optimizes the duty cycle of the second converter, which includes maximum power passage and maximum current into the battery. The main contribution of the proposed methods, is that the dynamic models of both the battery and the PV cell are taken into consideration, this greatly increases overall system efficiency.

The transport sector is a major consumer of energy, and thus a major contributor to greenhouse gas (GHG) emissions. The introduction of Electric Vehicles (EVs) has helped in mitigating some of the energy demands presented by the transportation system, though the electrical energy still needs to be secured through conventional and renewable resources. Searching for a new power source for vehicles has become necessary, due to incentives and policy initiatives to counter fossil greenhouse gas emissions. This study provides a new efficient Photovoltaic (PV) powered transportation system, which may be utilized instead of traditional public transportation systems. The main idea is to transform the transportation systems used by large campuses into green systems by deploying educated scheduling approaches and utilizing existing renewable energy infrastructures. The German Jordan University (GJU) campus was chosen as a case study. The presented work describes a comprehensive methodology to exploit the full capacity of the existing PV power plant coupled with the rescheduling of the transportation fleet to meet the energy availability and consumption demand. The proposed technique audits the existing renewable energy power plants for optimum operation. The results validate the efficiency of the proposed system and its ability to reduce carbon dioxide (CO2) emissions compared to traditional transportation systems with an acceptable payback period.

Power quality issues have recently become a source of major concern due to the large increase in load demand and the addition of various sources of disturbance at the distribution level. Power quality mainly refers to voltage quality. Sudden load variations can lead to a fall in the line voltage magnitude, creating what is called a voltage sag. Many solutions have been proposed and implemented for voltage sag compensation. Power electronics-based solutions such as grid-connected converters and AC/DC schemes are considered basic units for transient voltage fault ride-through capability. This paper describes a multifunctional intelligent bidirectional electrical vehicle (EV) charger that is able to charge the EV battery at different power ratings in addition to voltage sag compensation. The performance of the proposed system is verified and validated through MATLAB/Simulink simulations (R2020A). The proposed solution can effectively meet three main requirements: charging the EV battery at different power ratings, detecting the voltage sag event, and providing the required active and reactive power compensation for voltage sag compensation.