Design of Weigh Feeder Control System for Energy Saving Using Performance-Adaptive Method

This paper discusses a design method for the control system of a weigh feeder that supplies powder and granular material at a constant rate. Most weigh feeders employed in industry are controlled by proportional and integral （PI） compensation, and the control performance is decided by the selection of parameters. To attain advanced control performance by PI control, the PI parameters are designed on the basis of generalized minimum variance control （GMVC）. In this study, to achieve user-specified control performance by GMVC-based PI control, the design parameters of GMVC are automatically adjusted using a performance-adaptive method. The control performance discussed in this study consists of the variance of the control error and that of the difference in the control input. In a conventional performance-adaptive method, the variance of the control error is reduced. In this study, to reduce energy consumption and to achieve user-specified control performance, the variance of the difference in the control input is specified and the design parameter is determined. To demonstrate its effectiveness, the proposed method is applied to an actual weigh feeder.

Research on the cooperative train control method in the metro system for energy saving

Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.

Control performance and energy saving of multi-level pressure switching control system based on independent metering control

Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure switching control system based on independent metering control is proposed combined with the independent metering control technology.The configuration principle of the system is given,the mathematical model of this system is established,and the control strategy of the system under 4 different working quadrants is put forward.Finally,the control performance and energy saving characteristics of the system are tested.The test results show that the switching of high and low pressure power supply has a certain effect on the response of step position and ramp position under impedance working condition.The displacement curves show slow climbing or abrupt change of ramp position,and the position accuracy is less than 1 mm.The multi-level pressure switching control system based on independent metering control can recover and store energy under the transcendence working conditions.The control accuracy is about 1 mm,and the energy recovery rate is about 70%~80%.

A Stable Energy Saving Adaptive Control Scheme for Building Heating and Cooling Systems

This paper presents a stable, nonlinear, adaptive control scheme for building heating and cooling systems. The proposed controller utilizes the principle of adaptive one step ahead control and aims at reducing the energy consumed for heating or cooling a building. The design steps are discussed in details and a proof of global stability is also provided. Also, the performance of the proposed controller is demonstrated on a simulated building thermal model.

An Energy-Saving Control Strategy on Central Air-Conditioning System

An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy.

CROSS LAYER COORDINATED ENERGY SAVING STRATEGY IN MANET

Mobile Ad hoc NETwork (MANET) consists of a set of mobile hosts which can operate independently without infrastructure base stations. Energy saving is a critical issue for MANET since most mobile hosts will operate on battery powers. A cross layer coordinated framework for energy saving is proposed in this letter. On-demand power management, physical layer and medium access control layer dialogue based multi-packet reception, mobile agent based topology discovery and topology control based transmit power-aware and battery power-aware dynamic source routing are some of new ideas in this framework.

Pressure control strategy for pump motor energy transfer unit

Multi-level pressure source system is a novel hydraulic system with distinct advantage of energy saving. In order to balance each pressure level of the multi-level pressure source system, a pump motor energy transfer unit is usually equipped. However, the pump motor energy transfer has the characteristics of poor starting and low response, which cause long time of pressure adjustment and large pressure jitter when the transformer is switched to system suddenly and the motor-side pressure has pressure impact when rail of the pump-side is switched. To address these problems, this paper proposes a compound control strategy of feedforward compensation control with Fuzzy-PID to improve the controllability of the multi-level pressure source system. A test rig of the pump motor energy transfer unit is built and the controllability of compound controller and PID controller are compared. The experiment results show that, compared with the traditional PID, the adjustment time and the pressure impact are reduced by 20% and 25% with the proposed compound control strategy. Therefore, the presented compound control strategy can be used to improve starting performance and robustness of the pump motor energy transfer unit control system.

Control performance monitoring and advanced control towards energy conservation

High performance control of an interactive process such as iron and steel plant relies on ability to honor safety and operational constraints;reduce the standard deviations of variables that need to be controlled(e.g.product quantity,quality );de-bottlenecking the process;and,maximize profitability or lower cost(e.g.energy savings, improve hot metal content).These objectives may be prioritized in this order,but can vary and are very difficult to achieve optimally through conventional control.A multivariable predictive controller solution,along with its extensive inferential sensor and built-in optimizer,provides online closed loop control and optimization for many interactive metal and mining processes to lower the energy cost,increase throughput,and optimize product quality and yield. Control loop performance is also a key factor to improve iron and steel plant automation and operation result; Honeywell CPM offers vender-independent product which provides monitoring,tuning,modeling of control loop and sustainable loop performance analysis and maintenance solution towards operation stability and energy saving.

Design and Development of a New Control System for Improving Energy Efficiency and Demand Response

One of the best strategies for improving energy efficiency in any system is using the energy resources in the facilities properly.Using energy systems only when they are absolutely necessary is one of the best cost-benefit ratio strategies,i.e.the best energy saving strategy is,not using it.The aim of this paper resides on introducing a new Energy Management and Control System(EMCS),developed by the authors,which has been installed at the Universitat Politècnica de València.Alongside the paper,the architecture,the components and the installation cost analysis of the EMCS,as well as management actions implemented in the university and the obtained results are presented.Furthermore,this innovative system has been designed to improve demand response in energy systems by providing consumers with a tool for responding actively to energy demands,and also to provide all the different electrical market agents with a communication and business platform for exchanging information.

Energy Saving Analysis and Simulation for Home Electricity

This paper presents the energy saving method by applying the voltage control technique on a single-phase AC source to a thyristor rectifier and an IGBT inverter with LC filter. Based on the LC filter parameter, the values of the gain for the controller are obtainable. The proposed controller structure consists of two loops arranged in a cascaded model. The output of the first loop is the capacitor current. This current is added to the load current in order to obtain the current reference. This reference current value will be compared with the inverter current which produces the error signal to be fed into the second loop in the cascade system. The output of the second loop is the inverter voltage. This voltage is added to the load voltage to produce the voltage reference. This reference is fed to the pulse width modulation generator via the controller and compared with the triangular wave. This energy-saving circuit is designed in blocks using MATLAB Simulink.

Energy saving with node sleep and power control mechanisms for wireless sensor networks

Energy efficiency sleep scheduling in wireless sensor networks is one of the most crucial technologies. In this paper, we propose a simple and feasible synchronous node sleeping and waking mechanisms for small scale wireless sensor networks. Sensor nodes are divided into forwarding nodes and listening nodes. Beacon frame containing sleep command from the coordinator can be forwarded to listening nodes via forwarding nodes. All the nodes in the network can enter sleep at about the same time. Through such network synchronization mechanisms, we can realize synchronous sleep and wake of the entire network. Furthermore, a new power control scheme based on routing protocol （PCBRP） in the medium access control （MAC） layer is proposed. It operates with the help of routing protocol and calculates optimal transmission power according to the distance between neighbor nodes. A mapping table including optimal transmission power and node address is established during the route building procedure. The transmission power can be obtained by searching the table with the address of next-hop neighbor in subsequent data transmissions. The proposed mechanisms are implemented in sensor nodes and are evaluated in a test-bed. The analysis and evaluation based on the experimental results confirm that the proposed energy-saving mechanisms are feasible and effective.

Energy Saving and Pollutant Reduction: Nuclear vs Thermal

This paper presents the development status of thermal and nuclear power industries in China in recent years. It makes a comparison between the two industries from the aspects of reliability, economics, energy saving and pollutant reduction, by which the effects of expanding nuclear power on pollution control, resources conservation and eff icient energy use are evaluated, and several points of view are summarized.

Game analysis of building energy saving behaviors between government and developers

Information asymmetry phenomenon and the differences between the main body's earning targets,which are existing in the building energy saving field,have made the game behaviors of its economic activities become inevitable.There are strategies choice between government departments and the developers,when the building energy saving work is carried out under the government control.Based on the players based assumptions,the path of player's behavior strategy choices is analyzed,expected revenue models are established and mixed Nash equilibrium is obtained in this paper.Based on the analysis results,the incentive strategy enlightenment could be concluded that it is particularly important to design the scientific incentive system for developers to develop energy-saving buildings reasonably and for the government to implement effective control;the role of informal system in encouraging developers to develop energy-saving buildings should not be ignored.

Design of Fuzzy Controller for Central Air Conditioner

A structure of central air conditioning system in building and its running pattern are proposed in order to perform optimum energy saving strategy. The design of room temperature controller is taken as an example to discuss the design of fuzzy controller using common microprogrammed control unit (MCU) in detail. Based on fuzzy theory the query control tables fixed in read only memory (ROM) of MCU are established to realize the energy saving in the room temperature controller and the reasoning procedure is analyzed. The diagram of hardware design and the flow chart of software of room temperature controller are presented. The results show that the proposed method is practical and effective to achieve the energy saving goal.

High Speed On/Off Valve Control Hydraulic Propeller

The work-class remotely-operated-underwater-vehicles（ROVs） are mainly driven by hydraulic propulsion system,and the effeciency of hydraulic propulsion system is an important performance index of ROVs.However,the efficiency of traditional hydraulic propulsion system controlled by throttle valves is too low.Therefore,in this paper,for small and medium ROVs,a novel propulsion system with higher efficiency based on high speed on/off valve control hydraulic propeller is proposed.To solve the conflict between large flow rate and high frequency response performance,a two-stage high speed on/off valve-motor unit with large flow rate and high response speed simultaneously is developed.Through theoretical analysis,an effective fluctuation control method and a novel pulse-width-pulse-frequency-modulation（PWPFM） are introduced to solve the conflict among inherently fluctuation,valve dynamic performance and system efficiency.A simulation model is established to evaluate the system performance.To prove the advantage of system in energy saving,and test the dynamic control performance of high speed on/off valve control propeller,a test setup is developed and a series of comparative experiments is completed.The smimulation and experiment results show that the two-stage high speed on/off valve has an excellent dynamic response performance,and can be used to realize high accuracy speed control.The experiment results prove that the new propulsion system has much more advantages than the traditional throttle speed regulation system in energy saving.The lowest efficiency is more than 40%.The application results on a ROV indicate that the high speed on/off valve control propeller system has good dynamic and steady-state control performances.Its transient time is only about 1 s-1.5 s,and steady-state error is less than 5%.Meanwhile,the speed fluctuation is small,and the smooth propeller speed control effect is obtained.On the premise of good propeller speed control performance,the proposed high speed on/off valve control propeller can improve the effeciency of ROV propulsion system significantly,and provides another attractive ROV propulsion system choice for engineers.

Development of a power control system for AUVs probing for underwater mineral resources

Valuable mineral resources are widely distributed throughout the seabed. autonomous underwater vehicles (AUVs) are preferable to remotely-operated vehicles (ROVs) when probing for such mineral resources as the extensive exploration area makes it difficult to maintain contact with operators. AUVs depend on batteries, so their power consumption should be reduced to extend exploration time. Power for conventional marine instrument systems is incorporated in their waterproof sealing. External intermittent control of this power source until termination of exploration is challenging due to limitations imposed by the underwater environment. Thus, the AUV must have a power control system that can improve performance and maximize use of battery capacity. The authors developed such a power control system with a three-step algorithm. It automatically detects underwater operational states and can limit power, effectively decreasing power consumption by about 15%.

Automated Smart Utilization of Background Lights and Daylight for Green Building Efficient and Economic Indoor Lighting Intensity Control

The ways which are used today in order to light houses, offices, and most of the indoor areas are inefficient as a lot of energy is consumed unnecessarily during the day time. Mainly this problem because the interior lighting design consider the worst case when the light service is at night, which is not always valid. Also in most cases the lighting system design relies on people to control the lights switching on and off. This problem is also one of the design concerns in Green Building. In this paper, a solution to this problem and a method for people’s comfort who use the indoor facilities in industrial buildings is presented. In the proposed smart lighting system, lights switch on automatically when there is somebody in the room or in the occupied space and switch off when there is no occupancy. In addition to this known technique, adjustment of the brightness level of the lights will be possible via the personal computer or any other smart device. In this method, for the illumination level in the area, where is needed to be controlled for better energy saving, the light automatically is measured by the sensor and considering the amount of background lights coming from outside, automatically the brightness of lights is controlled to reach the preset level that determined for that room. By the means of this method, it is possible to provide better user comfort, avoid human forcedness to switch the light on and off, and hence effective energy saving. Arduino controller is used to build the controller and to demonstrate the results. Economic analysis was done to calculate the percentage of the energy saving that can be obtained by implementing the proposed smart lighting controller. As an outcome of the economic analysis, energy saving norm for an office with a standard size was calculated.

Design of the Control System of Adaptive Balancing Device Based on PLC

Due to the well condition and the un-expected imbalance movement of the pumping unit in use, the energy consumes a lot. The existing balancing equipment cannot adjust and monitor the pumping units in real time. Therefore this paper introduces the new adaptive balancing equipment—fan-shaped adaptive balancing intelligent device, projects a design of such control system based on PLC, and determines the principle of the control system, the execution software and the design flow. Site commissioning effect on Daqing Oilfield shows this fan-shaped adaptive balancing intelligent device can effectively adjust and monitor the pumping unit in real time, the balance even adjusts from 0.787 to 0.901, and integrated energy saving rate is 14.2%. It is approved that this control device is professionally designed, with strong compatibility, and high reliability.

An Electrothermal Model Based Adaptive Control of Resistance Spot Welding Process

Resistance Spot Welding (RSW) is a process commonly used for joining a stack of two or three metal sheets at desired spots. The weld is accomplished by holding the metallic workpieces together by applying pressure through the tips of a pair of electrodes and then passing a strong electric current for a short duration. Inconsistent weld and insufficient nugget size are some of the common problems associated with RSW. To overcome these problems, a new adaptive control scheme is proposed in this paper. It is based on an electrothermal dynamical model of the RSW process, and utilizes the principle of adaptive one-step-ahead control. It is basically a tracking controller that adjusts the weld current continuously to make sure that the temperature of the workpieces or the weld nugget tracks a desired reference temperature profile. The proposed control scheme is expected to reduce energy consumption by 5% or more per weld, which can result in significant energy savings for any application requiring a high volume of spot welds. The design steps are discussed in details. Also, results of some simulation studies are presented.

Intelligent Optimized Control System for Solvent Dewaxing Device

Methods for promoting product and reducing energy consumption in a solvent dewaxing device are putforward.Then,the authors mainly discuss about adaptive database,mathematical modeling,mathematical op-timized control algorithm,expert optimized control system and intelligent alarming system etc.At last,hard-ware and software of the intelligent optimized control system are introduced.Field test is finally chosen for thisstudy and proved that the intelligent optimized control system is effective.