In the paper, a model of a three-phase frequency-controlled induction electric drive has been developed in Simulink Matlab 2019 (MathWorks, Natick, MA, USA). This model is mathematically converted ...into a two-phase model by transforming equations. It is proposed to compensate the voltage drop in the power system during start-up operation under load by using supercapacitors as a buffer power source. A block of supercapacitors was calculated. Simulation modeling was performed at a different voltage than the network. The diagrams of the transient processes occurring in the electric drive when the power supply is changed were prepared. It was found that such a principle of implementing an additional source of electric energy allows to start induction electric drives in areas remote from industrial networks without significantly affecting their static and dynamic characteristics.
To identify the dynamics of asynchronous electric drives (AEDs) with frequency control, it is suggested to use nonlinear transfer functions and the equation of the family of frequency characteristics ...of an electric drive, which depend on the frequency of stator voltage and slip. The results of experiments and simulations that confirm the theoretical conclusions have been presented. The frequency characteristics of the board drive that are calculated by the suggested method have allowed one to explain the problems of frequency control unexplained by traditional methods, such as analytical, vector diagrams, equivalent circuits, etc. The same technique has allowed us to formulate the structural correction of AEDs, which improves the drive dynamics by almost twofold and makes it comparable with the dynamics of permanent magnet motors.
A model-algorithmic software for the automated electric drive of the solar-tracking system without light-sensitive sensors for areas with frequent deterioration of weather conditions has been ...developed. Dependences are derived that allow determining the azimuth and angle of declination of the Sun’s rays from the number of the day in the year and the time of day for any latitude of the globe. A universal algorithm for the operation of the positioning system has been developed and presented in the form of a flowchart. The applicability of the obtained model-algorithmic support is illustrated using the example of a two-linear solar tracker rotation system.
•Cradle-to-gate greenhouse gas emissions of internal combustion engine and battery electric vehicles are compared.•Greenhouse gas emissions of battery electric vehicles are 50% higher than internal ...combustion engine vehicles.•Traction battery production causes about 20% greenhouse gas emissions increase.•10% variations of curb weight, electricity and Li-ion battery production affect the results by 7%, 4% and 2%.•Manufacturing technique improvement, vehicle recycling and energy structure optimization are major mitigation opportunities.
Electric drive vehicles are equipped with totally different propulsion systems compared with conventional vehicles, for which the energy consumption and cradle-to-gate greenhouse gas emissions associated with vehicle production could substantially change. In this study, the life cycle energy consumption and greenhouse gas emissions of vehicle production are compared between battery electric and internal combustion engine vehicles in China’s context. The results reveal that the energy consumption and greenhouse gas emissions of a battery electric vehicle production range from 92.4 to 94.3GJ and 15.0 to 15.2 t CO2eq, which are about 50% higher than those of an internal combustion engine vehicle, 63.5GJ and 10.0 t CO2eq. This substantial change can be mainly attributed to the production of traction batteries, the essential components for battery electric vehicles. Moreover, the larger weight and different weight distribution of materials used in battery electric vehicles also contribute to the larger environmental impact. This situation can be improved through the development of new traction battery production techniques, vehicle recycling and a low-carbon energy structure.
The paper presents an experimental implementation of an optimal-based vibration control for a scaled wind turbine tower-nacelle structure. A laboratory model of the approximate power scale of 340 W, ...equipped with a nonlinear tuned vibration absorber (TVA), is analysed. For control purposes, a combined operation of a small-scale electric servo drive and a magnetorheological (MR) damper is used in the TVA system. Nonlinearities of both the electric drive and the MR damper are intrinsic parts of the adopted nonlinear control concept. The aim of the research is the simple-hardware real-time implementation and the experimental investigation of the simultaneous actuator and damper control, including the analysis of the influence of optimal control law parameters and quality function weights on the vibration attenuation efficiency and actuator energy demand. As a reference, an optimal-based, modified ground-hook control with the single goal of the primary structure deflection minimisation is used along with the passive system with zero MR damper current and idling electric actuator, proving the advantages of the proposed method. The regarded solutions guarantee 57% maximum structure deflection reduction concerning the passive TVA configuration, using an MR damper of 32 N maximum force and an electric drive of 12.5 N nominal force and 0.76 W nominal power. An interesting alternative is the optimal control concept tuned with regard to the actuator power minimisation—it provides 30% maximum structure deflection attenuation (concerning the passive TVA configuration) while using a passive damper of 3.3 N maximum force and an actuator of 0.17 W nominal power only. It makes evident the advantage of the properly tuned optimal control algorithm over the modified ground-hook law—it requires 51% less actuator energy than the latter parametrised to exhibit the same vibration attenuation properties.
Electric machines are critical components of the drivetrains of electric vehicles. Over the past few years the majority of traction drive systems have converged toward containing some form of a ...permanent magnet machine. There is increasing tendency toward the improvement of power density and efficiency of traction machines, thereby giving rise to innovative designs and improvements of basic machine topologies and the emergence of new classes of machines. This paper provides an overview of present trends toward high specific power density machines for traction drive systems. The focus will be on current technology and the trends that are likely to be pursued in the near future to achieve the high specific power goals set for the industry. The paper discusses machines that are applied in both hybrid and battery electric drivetrains without distinction and does not discuss the associated power electronic inverters. Future electric machine trends that are likely to occur are also projected.
This article analyzes the existing methods of increasing reliability through multiple overstatement of the installed power of electric equipment according to the criterion of minimum total yearly ...costs. The proposed method of optimization of power circuits of semiconductor converters includes stages of choosing the configuration of power circuits on the basis of the limit of semiconductor switches and choosing the optimal number of phases and redundant units. The distinguishing characteristic of the method is the criterion used, namely, the probability of failure-free operation. This new method reduces the cost of installed power of a semiconductor converter compared to the known synthetic method on the level of total annual costs. It is shown that this method has some degree of flexibility; e.g., the development of the element base can be considered on the basis of the corresponding coefficients that depend on the operating temperature of power semiconductor valves. The proposed method can be successfully used in the design of semiconductor converters for supplying powerful electric drives, where, in the general case, the number of phases of a power circuit is not three. In this case, multiphase windings of an electric machine are connected according to a scheme with potential phase separation, which can be considered as an equivalent multiple redundancy system.
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