Reliability Evaluation of Active Distribution Networks and Wastewater Treatment Plant Electrical Supply Systems

As energy demand increases in U.S. society, especially in terms of electricity and water, it becomes crucial for the operator to ensure the reliability and security of power distribution systems and wastewater treatment facilities. In the past, deterministic approaches were developed in evaluating the reliability of power supply systems. However, deterministic approaches lack the stochastic characteristic modeling, which makes it ineffective in modeling practical systems with increasing uncertainties. In this thesis, a set of probabilistic, quantitative reliability indices will be calculated for the active power distribution networks and wastewater treatment plant (WWTP) electrical supply systems. First, the probabilistic reliability evaluation for active distribution networks is performed. Due to the higher pressure from the environment, the integration of renewable resources and application of storage units has become more prevalent in the past several decades. Consequently, using the conventional deterministic approach to evaluate the reliability of active distribution networks may not be effective anymore. In this thesis, a new method is proposed to evaluate the active distribution system reliability containing microgrid and energy storage. The power output of distributed generator (DG) within the microgrid is first calculated based on the approach of generalized capacity outage tables (GCOTs). Then, the Monte Carlo Simulation (MCS) is utilized for performing power system reliability evaluation. The results obtained considering different energy storage capacities are compared. Furthermore, real-time pricing strategy is incorporated in optimizing the control strategy of the storage device. The reliability indices are then recalculated to inform the system operator in power system planning and operations. Second, the probabilistic reliability evaluation for WWTP electrical supply systems is conducted. Due to the rapid development of industry development and population growth, the electrical power supply system in WWTPs also demands a more comprehensive reliability evaluation, which is currently treated as a mechanical reliability problem in the wastewater treatment industry. In fact, the electrical part also plays an essential role in ensuring the availability and reliability of WWTPs. In this thesis, reliability evaluation mainly focuses on the electrical power supply system instead of the mechanical equipment. Furthermore, the Intelligent Power Motor Control Center (IPMCC) model is incorporated, which is widely used in WWTP control systems. A time-sequential MCS simulation method is used to derive the system reliability indices, and several other techniques are also utilized including the reliability model of IPMCC and the load based reliability indices calculation. A comparison is conducted between the reliability analyses of active distribution system in power systems and the electrical supply system of WWTP. In fact, both systems do have some similarities, such as the component reliability model and the evaluation procedure. However, in terms of some specific characteristics of each system, reliability modeling and evaluation methods may need some changes correspondingly

Simulasi Automatic Transfer Switch dan Automatic Mains Failure dengan Plc Omron Sysmac Cp1e

Electric power supply is the main requirement of equipment at the airport, therefore the reliability of the supply of power supplies is a top priority to support flight services. In addition to PLN as the main power supply the generator is used to supply a backup power supply. Automatic Transfer Switch (ATS) and Automatic Mains Failure (AMF) control systems are needed to regulate the switching of power supplies from PLN to Genset or vice versa. The ATS and AMF control systems use the Omron Sysmac CP1E PLC with a display using Easy Builder 8000 from Weintek which functions as an ATS and AMF monitor and control. Test results on ATS and AMF in manual and automatic modes, the system runs well.Keywords. Automatic Transfer Switch (ATS), Automatic Mains Failure (AMF), PL

A fully digital power supply noise thermometer

Power Supply Noise (PSN) is one of the main concerns in scaled technology circuits, both if performance reliability must be assured and if power supply is to be dynamically reduced for dissipation regulation. In this paper we propose a new system for digitally sensing Power Supply and Ground levels that can be both transferred to the output for verification purposes and used by a control block within the circuit under test (CUT) for the activation of power aware policies. The sensor system shows very low overhead in terms of power and area, and works at the nominal CUT frequency. It allows to change on-site the Power Supply and Ground ranges to be sensed and, after a fine tuning, can be arranged for a process variation aware measures. This sensor is fully digital and standard cell based and can be used for every type of architecture on a systematic basis for PSN measure as scan chains are for fault verification. It thus represents a change of paradigm in the way in which PSN measure systems are thought nowaday

Analisa dan Evaluasi Penggunaan SCADA pada Keandalan Sistem Distribusi PT. PLN (Persero) Area Pembagi Distribusi Riau dan Kepulauan Riau

One parameter of reliabilities from The Electrical Power Distribution System is the continuity of electrical power supply to the consumers. Therefore, it is needed a system that can monitor and control the performance of the distribution system in real-time and based on computers. The system which perform such these jobs is Supervisory Control and Data Acquisition (SCADA) system. The Distribution System has been integrated with SCADA can minimize the time disturbances that has effect to the reliability index of Electrical Power Distribution System. Use reability indexin this research refers to index of Electrical Power Distribution System that is the value of System Average Interruption Duration Index (SAIDI). This reliability index associated with the member disturbancesan and long disruption of the Distribution System. Index of Distribution System reliability of PT. PLN (Persero) APD Riau and Riau Islands has increased after the integration with SCADA systems. In this case percentage from reliability index Distribution System increase based on the analysis and calculation of SAIDI index value is 41.62%

Improving the reliability performance of medium voltage networks

The aim of this dissertation is to investigate alternative, more reliable and cost effective ways of improving the reliability performance of medium voltage networks. Customers are mainly affected by faults on the distribution MV network, to which, consequently, we have to pay particular attention. A major requirement on electricity supply systems is high supply reliability for the customer which is mainly determined by the distribution networks. Power system reliability is an essential factor in the quality of supply and is directly related to the number and duration of outages. By analysing the power system properly, the weaknesses will then be identified and improvements can be introduced to minimise the occurrence of outages. A decrease in the outage rate will result in an improvement in reliability and quality of supply of the distribution MV network. The dissertation focuses on improving the network management by increasing the level of network automation and control which improves the operating efficiency of medium voltage distribution networks. Steps are shown how to equip the network according to progressive investment capability, from Fault Path Indicators (FPIs) and remote control Pulseclosing technologies to automatic FuseSavers and Tripsavers used in a feeder automation scheme to minimise the number of disturbances and the outage durations experienced when they occur. The results of a study analysing the impact of different intelligent automation solutions on the reliability performance of Medium Voltage distribution networks are presented in the dissertation. The respective system topologies are modelled and the resulting system reliability performance is determined by reliability calculations such as the SAIDI and SAIFI values. The results show that the distribution automation technologies can have a very significant impact on both the SAIDI and SAIFI performance of the systems. Further, selected details related to the implementation of such intelligent automation schemes are presented in this dissertation

RELIABILITY EFFICIENCY OF ELECTRIC POWER SYSTEMS

The article deals with the general issues of definition and ensures power systems performance indicators, taking into account the required security of supply on the part of consumers and businesses generating opportunities and related electricity providers. The main traditional and advanced methods to ensure the reliability and evaluation of its effectiveness are provided. The authors formulate criteria for evaluating the effectiveness of reliability from the perspective of manufacturers, suppliers, consumers and others involved in the generation, transportation and transformation of electricity. The article points to specific tasks associated with reliability in supplying power system sites related to the schemes of internal and external power supply, and the possibility of theoretical analysis of internal power supply schemes, taking into account regulatory requirements on reliability of power supply mains of different categories, different costs to ensure the required reliability. The reliability is defined taking into account the reliability of elements, structural solutions and the redundancy, control in the circuit of the internal power supply, and the level of reliability provided by the electricity supply company

Assessing and augmenting SCADA cyber security: a survey of techniques

SCADA systems monitor and control critical infrastructures of national importance such as power generation and distribution, water supply, transportation networks, and manufacturing facilities. The pervasiveness, miniaturisations and declining costs of internet connectivity have transformed these systems from strictly isolated to highly interconnected networks. The connectivity provides immense benefits such as reliability, scalability and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cyber security threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety and security ramifications. One way to ensure vital asset protection is to adopt a viewpoint similar to an attacker to determine weaknesses and loopholes in defences. Such mind sets help to identify and fix potential breaches before their exploitation. This paper surveys tools and techniques to uncover SCADA system vulnerabilities. A comprehensive review of the selected approaches is provided along with their applicability

Development of a Control Strategy for the Hybrid Energy Storage Systems in Standalone Microgrid

The intermediate energy storage system is very necessary for the standalone multi-source renewable energy system to increase stability, reliability of supply, and power quality. Among the most practical energy storage solutions is combining supercapacitors and chemical batteries. However, the major problem in this kind of application is the design of the power management, as well as the control scheme of hybrid energy storage systems. The focal purpose of this paper is to develop a novel approach to control DC bus voltage based on the reference power\u27s frequency decomposition. This paper uses a storage system combined of batteries and supercapacitors. These later are integrated in the multi-source renewable energy system to supply an AC load. This technique uses the low-pass filters\u27 properties to control the DC bus voltage by balancing the generated green power and the fluctuating load. The hybrid storage system regulates power fluctuations by absorbing surplus power and providing required power. The results show good performances of the proposed control scheme, such as low battery current charge/discharge rates, lower current stress level on batteries, voltage control improvements, which lead to increase the battery life

Flexible Operation of Industrial Processes Acting as Power Reserves

Harvesting energy from renewable resources, such as wind and sun, is our priority. Wind power installed capacity in the UK and Nordic systems is increasing dramatically in recent years. However, one cannot precisely predict renewable energy output: if wind stops blowing, turbines don’t produce electricity. Moreover, we expect to receive power whenever we switch on or plug in electrical appliances. Since electricity cannot be stored efficiently, reserves must be available to continuously match the difference between generation and consumption. The number of occasions in which not enough reserves are available is growing because of renewable generation, increasing the risk of blackout. Conventional generators (e.g. gas-fired power stations) can control their power output to keep the frequency as close as possible to 50 Hz. This poster concentrates on flexible use of industrial plants, which can vary their electricity consumption and act as reserves whenever an imbalance arises. However, since flexibility is only a by-product of the plant, special care is devoted to assure stable and safe operation of the main industrial production: for instance, a plant that uses electricity to liquefy metal at high temperatures may reduce its power consumption for some time, provided that the metal doesn’t solidify. Industrial load flexibility is the largest unexploited resource in power system reliability: frequency control schemes must be revisited in light of load participation. The aim of this research is to prove that flexibility of industrial plants allows for more renewable energy integration while preserving supply stability

Protection of the Smart City against CME

AbstractToday life in many cities strongly depends on electricity. In many articles we can find designs of smart, clean and beautiful modern cities. All aspects of activity in cities are based on the use of control and supply systems. All of them use electricity as control signals and as power. A big but underconsidered problem is reliability of city substructures against Coronal Mass Ejection (CME) from the Sun. These events may damage elements of basic importance for life of people in cities. The article suggests some kinds of protection for the city substructures against CME