Current Regulation Mode Research Articles

Economic Analysis of Regulation Mode for Pump Unit Operating Condition

The setting of regulation mode for operating condition has great influence on the reliability and economy of pump units. For typical pumping stations, different adjustment modes of pump unit were calculated considering optimization operation and the equipment investment. The rationality of the regulation mode was analyzed from the economic perspective for the existing condition of pumping stations. The results show that the current regulation mode with adjusting rotational speed by variable frequency is reasonable in pumping station A, which can save more than 1.8 million yuan in operating costs every year. However, the current regulation mode with adjusting pump blade angles is not economical in pumping station B. If it is changed to adjusting rotational speed by variable frequency, which will save about 1.9 million yuan in operating costs every year. The results are of guiding significance to the design and selection of pump unit and the regulation mode.

Features of the Switching Regulator Operation оN a Rechargeable Battery

In connection with the widespread distribution of non-traditional and renewable sources of electricity, the task is to obtain from them the maximum possible amount of electric energy. As is known, to select from a power source of maximum power, it is necessary that the load impedance is equal to the output impedance of the source (harmonized mode). Under real conditions, the output resistance of the source depends on the external conditions, and the resistance of the load - from the mode of its operation. Therefore, the selection of maximum power from the source is possible only under a certain operating mode of the load. To enable selection from the generator of maximum power, when changing the external conditions and the mode of operation of the load between them include a matching device. As such, most often use switching regulator of voltage. Obviously, in such devices, the source of energy cannot be considered ideal and it is necessary to take into account its internal resistance. By adjusting the output current of the source, we will change the voltage drop on its internal resistance so, that the operating point of the generator is output to its maximum power zone. The internal resistance of the source of electric energy is significantly influence on the basis parameters and characteristics of the switching regulator of voltage. The peculiarity of using switching regulator of voltage as elements of renewable sources is that in order to ensure a even supply of electrical energy to a load, a battery, that works in a buffer mode, is connected in parallel to it. Switching regulator of voltage can also be used to regulate battery charging current in power supplies, electric cars, etc. In all these cases the battery determines the mode of operation of the switching regulator of voltage. Features of the switching regulator of voltage operation on the battery in the buffer mode, taking into account the internal resistances of the voltage source and the battery are analyzed. It is shown that under such conditions, switching regulator of voltage operates in the current regulation mode, but not voltage. Az the example, for switching regulator of voltage of the boost type determined the regulation characteristics for the modes of continuous and intermittent inductor current. It is shown that in order to reduce the dependence of the output voltage on the charging current of the battery, as well as to reduce the power loss therein, it is necessary to provide a certain relationship between the internal resistances of the electric power source and the battery. Graphs of regulation characteristics and the conditions of transmission from the energy source to the battery of the maximum possible power are determined. Recommendations on the application of modes of continuous and intermittent inductor current in the switching regulator of voltage when it operates on the battery are given. Ref. 13, fig. 5, tabl. 2.

Design and testing of a fuel cell powertrain with energy constraints

This paper reports a methodology to design a high efficiency fuel cell powertrain. The powertrain equips a prototype car that runs energy-efficient races where the objectives are to go the furthest with the lowest quantity of fuel (Shell Eco Marathon). In the design process, the starting point was the evaluation of the car's energy demand to run on a specified race track by developing a dynamic mechanical model of the car. A dedicated inertial test bench was constructed to reproduce the car's behavior in the laboratory. This was used to determine under which operating conditions an electric motor has to be powered to reach the highest efficiency. The introduction of ultracapacitors was envisaged and, based on efficiency arguments, a drive train arrangement was chosen composed solely of a 500 W PEFC stack, a DC/DC converter operated in a current regulation mode and an electric motor. Final tests of the powertrain revealed the most efficient operating conditions. The present work is the necessary first stage for both the design of the complete powertrain and its detailed energy analysis. It forms the basis for future improvements.

Investigation of LED Light Output Performance Characteristics Under Different Alternating Current Regulation Modes

LED performance characteristics under dc regulation modes have been studied extensively. But limited literatures are dedicated to studies of LED performance characteristics under different ac regulation modes. With direct ac powering LEDs for lighting application being available and more attractive in efficiency due to the elimination of ac-dc converter, investigation of the influence of different ac current regulation modes on LED performance characteristics becomes important and essential. This paper presents an experimental investigation of different current regulation modes on LED light output with different LED connection configurations. It is found certain current regulation mode under which a higher light output with the same absolute average current can be obtained. The result is due to facts that the absolute average current is the measurement of electrons and holes recombination rate inside the LED, and second-order nonlinear effect and thermal issue lead to the different light output for different ac regulation modes.

JT-60SA power supply system

The paper describes the main features of the Superconducting Magnets Power Supply to generate the toroidal and poloidal magnetic fields in JT-60SA tokamak, with special regard to coil current regulation mode and magnets protection.

Electronic Ballast Control IC With Digital Phase Control and Lamp Current Regulation

A digital control architecture is presented for electronic ballasts that provides a phase sweep for reliable, soft lamp ignition and a smooth transition to lamp current regulation mode. The controller is based on an inner phase loop for fast regulation of the resonant tank operating point and an outer current loop for lamp current regulation. The inner loop operates on a simple digital control law that computes the required gate timing relative to the inductor current positive zero crossing. Phase control provides reliable drive of the resonant converter in the presence of large dynamic changes in the load impedance during lamp ignition and warm up and natural tracking of component variations with temperature and time. The primarily digital approach provides programmability for broad application, insensitivity to process and temperature variations, realization in low cost CMOS processes and few external components. Experimental results are presented for an integrated ballast controller fabricated in a 0.8 mum CMOS process used in a 400 W, 150 kHz HID electronic ballast.