Raising Energy Efficiency of High-Head Drinking Water Pumping Schemes in Hilly India – Massive Potential, Complex Challenges

Investigations of energy efficiency of 25 pumps showed wire-to-water efficiencies ranging from 30% to 60%, with an average of 47%. Raising the efficiency of just 7 pumps to the realistic target of 60% would require an initial investment of 126 k€ and represent a net present value (profit) of 446 k€ over a 10-year pump lifetime, saving 8.6 kt of CO2 emissions. The primary measures for raising efficiency are in order of priority: 1) improving pre-filtration of raw water to prevent rapid mechanical wear due to suspended particles during monsoon, 2) providing training, improved working conditions, and better tools and spare parts among pump operators and 3) replacing aging, oversized pumps with properly sized pumps operating close to peak efficiency. As of January 2014 the results have been confirmed by a Bureau of Energy Efficiency-certified energy auditor and the extent and funding of efficiency measures implementation is in planning

Development of A Pressure Sensing Module and Flow Control System For A Prototype Pump Test Bed

Pump test bed is essential to ensure the proper functioning of a pump. However, a conventional pump test bed has some limitations during measuring the flow properties and variating the pump speed. As a result, a digital pump test bed can be a solution for measuring the flow properties more accurately. This article describes the construction process of a pressure sensing module for a digitalized pump test bed and control of flow by varying the speed of a prototype DC pump. A pressure sensing module and flow control system are constructed in this study to develop a prototype pump test bed as well as change the speed of the centrifugal pump. It is found that by using a piezoelectric pressure sensor in delivery pipe, the pressure sensing error is only 6.3% at the designed speed of pump and can be minimized by calibrating the sensor, fixing the leakage problem and increasing the pressure of flow. A wide variety of pump speeds can also be obtained by applying pulse width modulation principle without stopping the power supply

Flow regulation at constant head in feedwater pumps in a sugar industry

In this paper the feasibility of energy saving by implementing flow regulation at constant load in feedwater pumps in a sugar industry is studied. As regulation strategy, the use of a variable speed drive in the hydraulic system is proposed. For the project evaluation, the Net Present Value and Payback Period techniques are used. Among the variables considered are the price of energy, the equipment useful life, financial data and those related to environmental impact. As a result, it was found that if only a commercial approach is considered, the energy saving strategy is profitable but not attractive, because investment is recovered in a period close to the useful life of technology. However, if a government focus that encourages the implementation of these energies saving strategies is considered, the investment of the project recovers in a short time

Improved method for the scalar control of induction motor drives

Many control schemes have been proposed for induction motors, which are in themselves highly complex non-linear and sometimes internally unstable systems.One of themost accurate control schemes is encodered rotor flux orientated vector control. The advantages and disadvantages of this control are well known and several variations, or reduced vector schemes, have been proposed. This study introduces an improved encoderless scalar, or approximated vector, control method for induction machines which can be applied to general purpose applications that do not require the most precise control. The proposed method overcomes practical difficulties and is suitable for industrial applications. The slip compensated stator flux linkage oriented scheme proposed in this study does not require flux estimation or a speed sensor, only requiring nameplate data, stator current and stator resistance measurement, which can easily be determined at start-up. Simulation and experimental investigations including field weakening operation and the effect of stator resistance variation demonstrate the improved performance of the new scheme compared to previous open loop V/Hz and stator resistive compensated schemes especially at low rotor speeds

Application of calorimetric method for loss measurement of a SynRM drive system

Synchronous reluctance motors (SynRMs) are gaining in popularity in industrial drives due to their permanent magnet-free, competitive performance, and robust features. This paper studies the power losses in a 90-kW converter-fed SynRM drive by a calorimetric method in comparison of the traditional input-output method. After the converter and the motor were measured simultaneously in separate chambers, the converter was installed inside the large-size chamber next to the motor and the total drive system losses were obtained using one chamber. The uncertainty of both measurement methods is analyzed and discussed

Métodos de controle de vazão para racionalização de energia elétrica na irrigação por aspersão convencional / Control methods for energy electric rationalization in conventional sprinkler irrigation

O consumo de energia elétrica é um dos principais responsáveis pelos custos de produção na agricultura irrigada, mas um importante insumo para o crescimento e desenvolvimento econômico de uma região, em função da importância dos problemas relacionados ao consumo de energia no meio rural, é de grande valia a adoção de técnicas para reduzir o consumo de energia por meio da inserção de método de controle de vazão em sistemas de irrigação. Teve-se por objetivo no presente estudo analisar diferentes métodos de controle de vazão em sistemas de irrigação por aspersão convencional, com diferentes configurações de espaçamentos e áreas irrigadas, com enfoque no consumo de energia elétrica em projetos teóricos e simulados. Foram dimensionados sistemas de irrigação para cinco tamanhos de área (1, 3, 5, 7 e 10 ha), com diferentes combinações de espaçamentos entre aspersores e ramais de irrigação (12 x 12; 12 x 18; 18 x 18; 18 x 24 e 24 x 24 m), totalizando 25 projetos, em que foram aplicados três métodos de controle (nenhum controle de vazão e tempo de irrigação variável; controle por estrangulamento da válvula e tempo de irrigação fixo; variação da frequência elétrica e tempo de irrigação fixo) para a análise do consumo de energia elétrica. Portanto, a utilização de métodos de controle de vazão proporciona reduções no consumo de energia elétrica com valores de 9,12 até 50,45%, o método de controle que apresenta os melhores resultados de economia de energia é o com variação da frequência elétrica e tempo de irrigação fixo (inversor de frequência)

SINGLE PHASE TO THREE PHASE CONVERTER FOR VARIABLE SPEED DRIVE APPLICATIONS

This final report is mainly to give an overview about the “Single phase to Three phase converter for variable speed drive applications” project and also the progress of the project. Due to unavailability and high cost installation of three phase power network, power inverter is very important to address this problem. Here comes the purpose of the project to develop electronic converters that applicable for three phase equipment that equipped with variable speed drive (VSD) applications to operate in single phase supply. This project proposed two converter topologies for circuit modelling and simulation. There are PRC and PWM method. The modeling for the project will be done using PSPICE software. The model will be simulating based on the load requirement which is 3-phase motor for the converter design. Based on the simulation analysis it has been proved that these two methods can be implemented in order to achieve the project’s objective which to produce 3 phase power from single phase supply with improved performance and better efficiency. For this given time frame the project only focus on the methodology on how to develop the converter using proposed method but without control strategy. Further improvement or works can be carried out to improve the design by implemented control strategy for the converter

Medium voltage-high power converter topologies comparison procedure for a 6.6kV Drive Application using 4.5kV IGBT Modules

This paper presents a general comparison procedure for medium voltage - high power multilevel converter topologies and semiconductors, which is mainly based on analyzing the performance limits of the converters output characteristics such as the output voltage, current, active power, efficiency, etc. Afterwards, the general procedure is applied to compare some of the most relevant converter topologies oriented to a 6.6 kV drive application supplying quadratic torque loads and using 4.5 kV IGBT modules. The paper concludes evaluating the comparison factors of the different converter topologies and selected semiconductors obtained by the proposed procedure. The proposed procedure can potentially be extrapolated to any desired application framework

Development and Evaluation of Accelerated Environmental Test Methods for Products with High Reliability Requirements

Reliability testing of electronics is performed to ensure that products function as planned in specific conditions for a specified amount of time. This is usually both time-consuming and expensive and therefore test time acceleration is often required. The acceleration may be realized by using more severe stress levels or higher use cycle frequencies, but at the same time the risk increases of inducing failure mechanisms not relevant to the use conditions. As a consequence, the accelerated reliability testing of products with markedly long lifetimes and high reliability is frequently challenging. In this thesis different methods for test time acceleration for products with high reliability requirements and long service lives were studied. Both standard tests and modifications of these were used. The effect of the accelerated tests used on the failure modes and mechanisms observed was examined and the limitations of the test methods discussed. The research in this work was conducted at both interconnection level and at device level. The interconnection level testing focused on anisotropically conductive adhesive (ACA) flex-on-board (FOB) attachments. In addition to the effect of the curing process on the mechanical strength of ACA FOB attachments, their applicability and long-term performance in industrial applications was studied. According to the real-time resistance measurement the assembly tested was observed to be extremely resilient in thermal cycling and hygrothermal aging. However, a significant decrease in the mechanical strength of the FOB attachment was also seen. Hydrolysis and embrittlement of the flex material was also observed to limit the applicability of harsher hygrothermal aging conditions. Clear ACA joint failures were only observed with moisture condensation testing, but this may not be a suitable test method for applications that are not susceptible to such a stressor. The device level testing comprised reliability analysis of two frequency converter models. The older generation device and its field failure data were used as the starting point in the development of a test method that could be used to minimize testing time and to induce comparable failure modes to those occurring in the use conditions of the devices. The tests showed that only with the simultaneous use of stresses could a significant reduction in the testing time be achieved. However, the application of the same test method to the newer generation device proved challenging because of differences in materials, components and layouts. Although similar failure modes were observed in both devices, the combined effect of the stresses used on the failure mechanisms requires further study. In addition, knowledge of the service conditions, the environmental stresses and their severity is critical. The main disadvantage of simultaneous stress testing was observed to be the interpretation of the test results, especially due to the complexity of the devices tested. Moreover, the results obtained may be highly application specific. However, regardless of the difficulties in the lifetime estimation, the use of combined stresses was observed to be a practical method to study the weaknesses in a product