Top PDF Design, Specification, and Synthesis of Aircraft Electric Power Systems Control Logic

Design, Specification, and Synthesis of Aircraft Electric Power Systems Control Logic

Design, Specification, and Synthesis of Aircraft Electric Power Systems Control Logic

The synthesis process produces a control protocol in the form of a finite state automaton. The resulting automaton for the electric power system centralized controller takes roughly one minute to solve on a MacBook Pro with a 2 GHz Intel Core Duo processor, and has 200 states. Within each automaton state is a list of successor states, which represent possible configurations for the system depending on the behavior of the environment states. Once the environment acts, then the system responds and the automaton steps to its next state. From State 0, for example, the automaton can move to State 1 if all generators and APUs become unhealthy, or move to State 2 if the right APU remains healthy but the other three power sources become unhealthy. Note that State 1 has no successor states because its environment violates the assumption that at least one power source remain healthy at all times. Thus as long as the environment satisfies its assumption, then the system will satisfy its specifications. We can also synthesize a centralized case where the total number of contactors allowed to switch at each particular time step is limited by hardware constraints. Consider contactors C1, C2, C5, and C6 to be controlled separately because they are connected to generators. The remaining three contactors, however, are physically controlled by a single hardware that is only capable of switching two contactors at one time. This problem, with the environment assumption (one source is always healthy), no longer becomes realizable as it violates the safety requirements for buses. If the environment assumption is relaxed, i.e. at least two sources must always remain powered, then the problem once again becomes realizable. A similar approach holds for the case when only one of the three middle contactors can be switched at one time.
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Control design and voltage stability analysis of a droop controlled electrical power system for more electric aircraft

Control design and voltage stability analysis of a droop controlled electrical power system for more electric aircraft

In the specific context of aircraft power systems, so far, several publications have discussed the system stability in MEA EPS. The stability of a switched reluctance motor-based 270V DC EPS has been analyzed in [20]. A permanent magnet synchronous generator (PMSG)-based hybrid AC-DC MEA EPS is investigated in [21], [22] and the influence of parameter variation on system stability is presented. Nevertheless, the published works on the context of MEA EPS are mainly focused on the single source system, droop control is not used and the dynamics of the generator is not taken into account. In [23], stability of a single DC bus MEA EPS with multiple generators is investigated. However, the interaction of the parallel sources including the steady-state power sharing performance is not validated experimentally, and the impact on stability of different operating frequencies of the different sources is not addressed.
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Control design for PMM based generator fed by active front end rectifier in more electric aircraft

Control design for PMM based generator fed by active front end rectifier in more electric aircraft

The future aircraft electrical power system is expected to be more efficient, safer, simpler in servicing and easier in maintenance. As a result, many existing hydraulic and pneumatic power driven systems are being replaced by their electrical counterparts. This trend is known as a move towards the More-Electric Aircraft (MEA). As a result, a large number of new electrical loads have been introduced in order to power many primary functions including actuation, de-icing, cabin air- conditioning, and engine start. Therefore electric power generation systems have a key role in supporting this technological trend. Advances in modern power electronics allow the concept of starter/generator (S/G) which enables electrical engine start and power generation using the same electrical machine. This results in substantial improvements in power density and reduced overall weight. One of the potential S/G solutions is to employ a permanent magnet machine (PMM) controlled by active front-end rectifier (AFE). Operation of the PMM as a generator at wide range of speed that is dictated by the engine and electrical loads connected to the aircraft bus require careful design of the controllers. Corresponding plant models are derived and verified with simulations using developed models in Matlab/Simulink. The relevant controllers are designed based on the derived plants and operating points. The controllers are tested with Simulink models and experimentally using a scaled prototype of the investigated generator system.
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Control of DC power distribution system of a hybrid electric aircraft with inherent overcurrent protection

Control of DC power distribution system of a hybrid electric aircraft with inherent overcurrent protection

Abstract—In this paper, a novel nonlinear control scheme for the on-board DC micro-grid of a hybrid electric aircraft is proposed to achieve voltage regulation of the low voltage (LV) bus and power sharing among multiple sources. Considering the accurate nonlinear dynamic model of each DC/DC converter in the DC power distribution system, it is mathematically proven that accurate power sharing can be achieved with an inherent overcurrent limitation for each converter separately via the proposed control design using Lyapunov stability theory. The proposed framework is based on the idea of introducing a constant virtual resistance at the input of each converter and a virtual controllable voltage that can be either positive or negative, leading to a bidirectional power flow. Compared to existing control strategies for on-board DC micro-grid systems, the proposed controller guarantees accurate power sharing, tight voltage regulation and an upper limit of each source’s current at all times, including during transient phenomena. Simulation results of the LV dynamics of an aircraft on-board DC micro-grid are presented to verify the proposed controller performance in terms of voltage regulation, power sharing and the overcurrent protection capability.
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Active Return-to-Center Control Based on Torque and Angle Sensors for Electric Power Steering Systems

Active Return-to-Center Control Based on Torque and Angle Sensors for Electric Power Steering Systems

Abstract: This paper presents a complete control strategy of the active return-to-center (RTC) control for electric power steering (EPS) systems. We first establish the mathematical model of the EPS system and analyze the source and influence of the self-aligning torque (SAT). Second, based on the feedback signals of steering column torque and steering wheel angle, we give the trigger conditions of a state switch between the steering assist state and the RTC state. In order to avoid the sudden change of the output torque for the driving motor when the state switches frequently between the steering assist state and the RTC state, we design an undisturbed state switching logic algorithm. This state switching logic algorithm ensures that the output value of the RTC controller is set to an initial value and increases in given steps up to a maximum value after entering the RTC state, and the output value of the RTC controller will reduce in given steps down to zero when exiting the RTC state. This therefore ensures smooth switch control between the two states and improves the driver’s steering feeling. Third, we design the RTC controller, which depends upon the feedback signals of the steering wheel angle and the angular velocity. In addition, the controller increases the auxiliary control function of the RTC torque based on vehicle speed. The experimental results show that the active RTC control method does not affect the basic assist characteristics, which effectively reduces the residual angle of the steering wheel at low vehicle speed and improves the RTC performance of the vehicle.
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HYDRO ELECTRIC POWER DAM CONTROL SYSTEM USING FUZZY LOGIC

HYDRO ELECTRIC POWER DAM CONTROL SYSTEM USING FUZZY LOGIC

295 | P a g e recognition of storage volume non-specificity in the discrete Stochastic Dynamic Programming (SPD) [3].Fuzzy dynamic programming model was used for Hirakud dam in the State of Orissa in India in which irrigation; hydropower generation and flood control were considered as fuzzy variables [4].The neural network and fuzzy systems were also adopted for dam control in which a comparison was made between reservoir operations using the fuzzy and neural network systems and actual one by operator, using examples of floods during flood and non-flood seasons [5].Reports show that hydroelectric dams produce 20 percent of the world’s total production of electrical energy. The development of a hydro-electric power dam control system based on fuzzy logic with two inputs and two outputs. Using water level and flow rate measuring devices for feedback control, and two control elements for draining and valve controlling (release), and formulated fuzzy rules for water level and flow rate has been achieved.To control the water release, the controller reads the water level and flow rate after every sampling period. This proposed design work of Hydro-Electric Power Dam System is the application of fuzzy logic control system consisting of two input variables: water level and flow rate, and two output variables: Drain valve and (Releasing) Valve control used in a reservoir plant of Hydro-Electric Power Dam to monitor the system of Dam.
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A Review on Configurations, Control, and Future of Hybrid Renewable Energy Systems for Electric Power Generation

A Review on Configurations, Control, and Future of Hybrid Renewable Energy Systems for Electric Power Generation

allows reaching particularly high power-to-weight or high energy-to-weight densities. Compared with other commercially available batteries, conventional Li–ion batteries excel in performance with the exception of cost and life expectancy. Since the cost is relatively high, the main interest relates to mobile applications. Through the vehicle- to-grid (V2G) concept, Li–ion batteries are expected to appear as active resources in distribution networks. Hydrogen can serve as an energy carrier for capacity-oriented energy storage. Hydrogen may be produced through electrolysis, where water is split into its component parts of hydrogen and oxygen. The electrolysis can be powered from renewable sources. Hydrogen may also be derived through steam reforming from methane or natural gas. The amount of power that can be provided from hydrogen depends on the size of the fuel cell stacks. Hydrogen is flexible in that it can be stored in tanks without disturbing self-discharging effects and can also be used to fill the tanks of fuel cell cars quickly. In stationary applications that use electrolyzers to produce hydrogen and fuel cells to generate electric power, the comparatively low round-trip efficiency is known to be a disadvantage. Very popular in large-scale power systems is the usage of pumped hydro energy storage. It relies on the availability of a suitable geology and is, therefore, not considered further here. Compressed air energy storage is also not considered for the same reasons. In Table II, the storage types that can be considered for hybrid energy systems and have been discussed above are classified. None of the technologies rely on local geology. Whether a battery is designed for high-power or high-energy depends on its intended application.
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Improving Efficiency of Active Power Filter for Renewable Power Generation Systems by using Predictive Control Method and Fuzzy Logic Control Method

Improving Efficiency of Active Power Filter for Renewable Power Generation Systems by using Predictive Control Method and Fuzzy Logic Control Method

A simulation model for the three-phase four-leg PWM converter with the parameters shown in Table-2 has been developed exploitation MATLAB-Simulink. The target is to verify the present harmonic compensation effectiveness of the projected control theme under completely different operational conditions. A six-pulse rectifier was used as a nonlinear load. The projected predictive control formula was programmed exploitation an S-function block that permits simulation of a separate model that may be simply implemented during a real-time interface (RTI) on the dSPACE DS1103 R&D control board. Simulations were performed considering a 20 [μs] of sample time.
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Improving Efficiency of Active Power Filter for Renewable Power Generation Systems by using Predictive Control Method and Fuzzy Logic Control Method

Improving Efficiency of Active Power Filter for Renewable Power Generation Systems by using Predictive Control Method and Fuzzy Logic Control Method

Abstract - In this paper, an active power filter was implemented with a four-leg voltage-source inverter using a concept of predictive control along with fuzzy logic controller was presented. Here we are using fuzzy logic controller instead of using other controllers. The utilization of a four-leg voltage-source inverter allows the compensation of current harmonic components, as well as unbalanced current generated by single-phase nonlinear loads. A fuzzy controller is designed to mitigate the total harmonic distortion. Under steady state and transient operating conditions, the proposed active power filter compensation performance and the control strategy associated was demonstrated through simulation results. The simulation was done by using MATLAB/Simulink software.
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Power management optimization of hybrid power systems in electric ferries

Power management optimization of hybrid power systems in electric ferries

The DC HPS with a BESS can be considered a promising solution to reduce emissions and noise in harbors to significantly low levels. In order to increase the potential of such a system, an efficient power management strategy is essential which can optimally share power among all HPS components. In this context, modeling a simulation platform is vital to derive an efficient power sharing strategy and thereby achieve fuel savings and emission reductions. Power and size optimization approaches for land-based HPSs have been extensively discussed [34, 35]. However, modeling, simulation and power management optimization of electric ferries with HPSs have not been extensively discussed. Only a few studies have discussed the use of HPSs in domestic ferry and boat applications, which mostly used classical and deterministic PMS methods [36-41]. In [36], the authors have studied and designed a hybrid fuel cell electric propulsion system for a domestic ferry and compared it with the performance of the existing diesel propulsion system. In [37], the development and demonstration of a fuel cell/battery hybrid system for a tourist boat is presented. In [38], the authors have investigated the effectiveness of using a hybrid system with battery in a passenger ferry. In [39], the authors proposed a hybrid fuel cell/battery power system for a low power boat. A classical energy management system, namely a state-based method, is used to manage the power generation. In [40], authors proposed an energy management system based on a deterministic state-based control method to manage the energy of a hybrid fuel cell/battery passenger ferry. In [41], the authors presented a techno-economic approach to minimize the overall cost of an ESS in a supercapacitor plug-in ferry. The aforementioned studies have not considered modeling, simulation, and evaluation of a hybrid domestic ferry with DC distribution and a BESS in terms of fuel savings and emission reductions. Moreover, to the best of our knowledge, the power management of DC HPSs for short haul ferries integrated with a BESS using a meta- heuristic method has not been reported in the existing literature.
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Fuzzy Logic Based Automatic Load Frequency Control of Multi-Area Power Systems

Fuzzy Logic Based Automatic Load Frequency Control of Multi-Area Power Systems

of frequency and power flow [4]. Interconnected multiple- area power systems can be depicted by using circles. A simplified four area interconnected power system used in this study, each area can be represented as equivalent generating unit and interconnected through lossless tie-lines with some reactance. As simplified four-area interconnected power systems as shown in Fig. 1 [6].

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Charging of electric vehicles as reserves of power systems

Charging of electric vehicles as reserves of power systems

Tampereen teknillinen yliopisto (TTY ).. UPS systems Smart grids has two main functions, which are challenges to the distribution system: 1) Enabler of energy-efficient and environmental[r]

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AIRCRAFT DEPARTURE CONTROL SYSTEMS – HIDDEN SAFETY RISKS

AIRCRAFT DEPARTURE CONTROL SYSTEMS – HIDDEN SAFETY RISKS

Departure Control System offers efficient, fast, easy-to-use solution to mass and balance calculation. By integrating the check-in functions, movement messages, load control, the costs are lower; process is faster and overall more accurate. Strict time and use logs offer transparency, increase safety, and eliminate many risks considering the human error. However, these systems are far from error-proof, and the critical view combined with regular inspection is a key of maintaining the safety level. All the errors that plague software – form bad programming, to glitches and use errors are always present, and a key to safety is to always keep the employees aware of the background process and to let them know that the system is not always correct with its calculation. Therefore, the paper provides contribution to understanding L-S interaction within the SHELL model, whereas the block labeled “S” represents the interaction of the central liveware component “L” with software, that is, the non-physical aspects of his human machine systems. Therefore, authors analyzed three DCSs with integrated and separate functions, and they concluded that the integrated solution is a safe way to operate. Additionally, different versions of the system customized for the certain airline can contain errors within itself, which don’t appear on the other versions, so the key to safe use within the airline is periodic inspection and testing of manual and system calculations. Most dangerous risks are those very well hidden in the background
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Generator Control System Used in Aircraft Power Supply

Generator Control System Used in Aircraft Power Supply

Abstract- Aircraft have two primary sources of electrical energy. The first is the generator, which converts mechanical energy to electrical energy. The second is the battery, which converts chemical energy to electrical energy. The generator is the main source and the battery is the auxiliary source. In aircraft, the electrical system is primarily an AC system. Aircraft electrical components operate on many different voltages both AC and DC. However, most of the systems are 115 VAC with 400 Hz, 28 VDC and 26 VAC is also used in aircraft for lighting. DC is also supplied from a battery installation. The battery provides 28 VDC. The function of the electrical system is to generate, regulate and distribute electrical power throughout the aircraft. New generation aircraft rely heavily on electrical power because of the wide use of electronic flight instrument systems. For aircraft constant frequency systems 400 Hz has been adopted as the standard. The application of 400 Hz frequency, which is higher than usual frequencies, offer several advantages over 60 Hz - notably in allowing smaller, lighter power supplies to be used for aircraft operations and computer applications.
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Control and power management of photovoltaic systems with plug in hybrid electric vehicles as energy storage

Control and power management of photovoltaic systems with plug in hybrid electric vehicles as energy storage

This section will address techniques which have been specifically designed to handle tracking the GMPP under non-uniform environmental conditions. These techniques are capable of distinguishing the GMPP from multiple local MPPs under partial shading conditions (PSCs). These techniques include line search with Dividing Rectangle (DIRECT) [158], Fibonacci sequence [159], [160], PSO and SA. One drawback of some of the GMPPT techniques such as PSO and SA, is that reinitialization conditions are needed to re-initialize the algorithms when a sudden change in solar irradiance occurs. This change may be attributed to a change in the shading pattern of PV systems, which is mostly likely a consequence of passing clouds over PV systems. If the reinitialization conditions fail to detect a sudden change in solar irradiance, the algorithms are not able to track the new GMPP. Thus, some of the GMPPT algorithms are unable to perform a continuous tracking, which can be resolved by combining the algorithms with a conventional MPPT technique such as P&O and IC, to form a two-stage method to ensure the continuous operation of a PV system at GMPP. PSO and SA GMPPT algorithms are our main focuses in this section since they are belonged to the category of artificial intelligent algorithms and are able to provide good performances in tracking to the GMPP under both uniform and non-uniform conditions [90]. These GMPPT algorithms will be fully explained in the following subsections.
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The logic design of a digital control computer.

The logic design of a digital control computer.

The computer uses a recirculating, magnetostrictive delay line as the main data memory, STORE S. Magnetostrictive delay lines are passive electromechanical devices capable of delaying electrical signals. They reduce the velocity of an electrical wave by converting it to a sound wave and then reconverting it to an electrical signal. The delay line pack includes gating logic for entering infoiroation into the memory and a flip-flop to provide both assertion and negation outputs.

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Examination of Aircraft 's Cable Control Systems Tension

Examination of Aircraft 's Cable Control Systems Tension

may fluctuate at the level of technical acceptabil- ity, i.e. approx. 10%. An important aspect for air- craft designers and Aircraft Maintenance Instruc- tions preparation is the necessity of clearly defin- ing the conditions for examining extensiometers, i.e. determining the length of reference lines and their preparation, i.e. for example pre-tensioning (so-called cable training [6]) with specific values and defining the basis and value of forces used tensiometers. It seems appropriate to collect the stiffness structural and cable system data at the stage of structural tests, and further collect infor- mation on stiffness during flight tests at different ambient temperatures. This approach will reduce the measurement error to about 5–7%.
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ADIABATIC LOGIC FOR LOW POWER DIGITAL DESIGN

ADIABATIC LOGIC FOR LOW POWER DIGITAL DESIGN

Our aim is to decrease to energy expended per switching operation. Only measuring the power consumption is not sufficient in CMOS design. A design can consume very low power to perform a particular operation at low frequency but may take very long time to finish the operation. Therefore it becomes necessary to measure the energy dissipation. Thus the performance of the CMOS design is analyzed by calculating the PDP(power delay product) which is product of average power consumption and propagation delay TD.[2][4]

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Design And Vibrational Analysis Of Electric Power Generator

Design And Vibrational Analysis Of Electric Power Generator

fossil fuel such as petrol or diesel is affected and not good for environment. Internal combustion engine that in system of the generator must be changed and develop to overcome the problem of earth’s environment. These generators produce power independently, but the smoke emission and noise pollution are still the main issues for green environment effects. Moreover, these generators are using fossil fuel which is not sustainable.

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A Novel Method of Power Flow Control for the Compensation of Harmonics and Unbalanced Currents in Electric Railway Systems

A Novel Method of Power Flow Control for the Compensation of Harmonics and Unbalanced Currents in Electric Railway Systems

Abstract— This paper presents a novel method of power flow compensation of broad filtering and unbalance return system for electric traction systems using fuzzy logic controller. For a balanced three-phase three- wire system, the planned technique is able to control the power flow switch among the grid and the load so that the immediate compound power is maintained steady. As a result any nonlinear unbalanced load is seen by the three-phase sup- ply as a balanced linear load. The planned filter is evaluated on power substations with open delta (V-V) and Scott transformer feeders and for two-level and dual-converter in the power stage. The system has been simulated. The outcome from simulation tests shows the fuzzy logic controller advantages and the applicability compared with the direct control based algorithm in Electric railway systems
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