In this paper, a high-frequency dimmable electronic power supply for the highpressure sodium lamp is presented. The method includes a full bridge rectifier generating a dc-link voltage and a half bridge inverter to generate a frequency swept lamp power signal to drive the lamp while avoiding acoustic resonance. A dimming technique for a resonant circuit electronic ballast based on a variable frequency is introduced. In addition, the ability in the dimming range is demonstrated by experiments and simulation in order to verify the performance of the proposed circuit. A dimming range from 100% to 50% has been achieved. The efficiency is always higher than 89% and the ballast can accurately follow a fixed dimming plan.

The main advantages of high-frequency electronic ballasts for high-intensity discharge lamps are high luminous efficacy, small size, lightweight and longer lifetime. This is why high-intensity discharge lamps operating at high frequency are widely used. This paper proposes an approach for designing resonant circuit electronic ballasts controlled by frequency variation for high-intensity discharge lamps. The proposed technique including an AC/DC rectifier, a power factor correction circuit and a DC/AC half bridge inverter. These electronic ballasts offer a wide range of dimming controls and can avoid acoustic resonance. However, under dimming, the electric and photometric characteristics of the lamp change. In order to study these effects under the process of dimming, this work studies the lamp properties by varying both lamp power and operating frequency.

Results of spectral and photometric measurements are presented for pulsed power operated high intensity discharges (HIDs). This investigation is related to the application of a pulsed power supply for pile driving of HID lamps. Specifically, we are interested in controlling the spectral response radiation of visible and ultraviolet (UV) lines for tertiary treatment of water using UV radiation. Simulations based on a physical model of the lamps were conducted. These results relate to the radial temperature, line intensity and electrical properties (voltage, power and conductivity). Good agreement has been found between the results of the simulations and the experimental findings.

Growing population and limited energy resources have impacted energy consumption. Limited fossil fuel resources and increased pollution threaten national and human societies. These elements emphasize energy sources. Renewable energy use affects growth. All new energy sources, including renewables, are crucial for global economic growth. Economic and environmental issues have led to new approaches in international environmental law, including the green economy. This study employs structural vector auto-regression (SVAR) to compare the effects and outcomes of increasing the use of renewable energy in the context of economic growth and greenhouse gas emissions in middle income countries (MICs) and high income countries (HICs). The results show that these indicators demonstrate that the production of energy from renewable sources has positive short-term and long-term economic effects with varying contributions. However, renewable energies have a greater impact on the green economy in selected MICs than in selected HICs. Therefore, the promotion of macroeconomic indicators is viewed as one of the reasons for the development of policies to increase energy production from renewable sources in selected countries.

In this paper, the dimming effects on the photometric and electric characteristics of high intensity discharge lamps supplied by a low frequency square waveform are evaluated. For this evaluation an electronic ballast is presented. The ballast consists of a current source, AC/DC converter and a full-bridge inverter. The electronic supply provides to the lamp a different form of current excitation (square waves with variable short drops). Dimming control and the characteristics of low frequency operated high intensity discharge lamps are described. The lamp is represented in a simulation by its conductance model and coupled to its electronic power supply. Experimental results are shown and compared with the simulation. A dimming range from 100% to about 60% has been achieved.

In this paper, bi-level optimization model is proposed for optimal energy trading between microgrids (MGs) and distribution companies (Discos) with consideration of the renewable energies. The first level modelling is maximizing MGs’ profit and the second level is related to maximization of the Discos profit. In proposed system, power trading between MGs and Discos is considered. As well, renewable energies and demand management strategy are modelled in system for optimal energy consumption. The optimization modelling is solved by Particle Swarm Optimization (PSO), and results of the two case studies show optimal solution of prosed strategy in energy optimization.

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This paper deals with radiation transfer in a cylindrical high pressure HgTℓI discharge for which local thermodynamic equilibrium can be assumed. The discrete ordinates method (DOM) is used to solve the radiative transfer equation. Calculations of concentration profiles of all species have been performed using a parabolic temperature profile and a constant mercury/thallium ratio throughout the discharge tube. The influence of thallium in HgTℓI discharges on the spectroscopic parameters such as the spectral intensity, the radiative flux and the net emission coefficient is studied. A comparison of the calculated thallium line shapes with the measured ones shows good agreement.