Premium Power Research Articles

Premium Power Supply Scheme for Data Center With SMES and DG Integration

Premium Power Supply Scheme for Data Center With SMES and DG Integration

Simulations of a possible configuration of Premium Power Park

The voltage dip and the sudden electrical energy interruption are, probably, the most important disturbances of the power quality in the electrical system. Several technical solutions exist to mitigate voltage dips, respectively at plant or system level as for example: • the installation of Custom Power (CUSPO) for a single customer; • the Premium Power Park (PPP) for a group of customers. According to the PPP concept, the tenants of an industrial or commercial office park would be provided with a guaranteed level of electrical service quality made possible by Custom Power devices, such as the Dynamic Voltage Restorer (DVR), the Distribution Static Compensator (DSTATCOM – Distribution STATCOM), the medium voltage Static Transfer Switch (STS). The paper summarizes the Premium Power Park idea and a possible configuration of it, studied by ERSE, including the system aspects and the analysis of the combined operation or interaction of the Custom Power.

Premium Power Service for Custom Power Devices Based on Trial-Purchase Model

Premium Power Service for Custom Power Devices Based on Trial-Purchase Model

Premium power investment strategy utilizing the economy of scale of custom power devices

The possible existence of ‘economy of scale’ in manufacturing poor power quality (PQ) mitigation devices motivates customers to participate in a common mitigation solution. A custom power park (CPP) is an option where the CPP operator offers a set of custom solutions to a group of customers. Given that these custom solutions comprise one or many custom power devices, both CPP operators and the customers are expected to coordinate to obtain individual mitigation device ratings while maximizing the overall utility of customers. Here, CPP operators would calculate ratings of custom solutions and associated unit cost for the minimal total cost, while the customers are expected to select custom solutions to maximize their overall benefit. Furthermore, the customers utilize their willingness-to-pay function in this process and strictly participate in this arrangement if the utility received is more than their self-generated non-negative utility. Without the CPP operator, customers would form a CPP-like arrangement to recover the cost of investment and operation and maintenance. This combinatorial problem has been solved in two stages, involving the calculation of independently generated utility in the first stage and the overall CPP designing problem in the second stage. While customer and operator-side nonlinearities in the cost functions have been suitably discretized, the proposed methodology ensures that the solution space remains intact. The proposed method is illustrated using three devices, three custom solutions, and three customers. • Existence of economy of scale is a motivating factor for common mitigation solution. • A system-wide PQ improvement might not lead to a socially justifiable outcome. • Customers participate if utility received is more than self-generated utility. • Proposed method converts the MINLP problem into MIP. • Proposed methodology could be used for complex problems with similar structure.

A novel premium power supply scheme against harmonic suppression for non-linear park

• A method for harmonic-suppression needs identification is proposed to guide non-linear customers to actively participate in harmonic mitigation. • The novel premium power supply scheme against harmonic suppression for non-linear park can effectively solve the harmonic problems with the situations that all the participants are satisfied. • A DEA-based method is proposed to reasonably realize allocation of the scheme costs. • The proposed scheme provides the possibility for the power grid and customers to jointly control harmonic problems. With the continuous development of power grids, the power electronization rates of power systems are increasing, and problems caused by harmonic pollution are becoming major concerns. Generally, harmonic problems result from the electric utility and non-linear customers, thus the mutual collaboration of both parties is crucial to addressing these problems. However, due to the indeterminate needs of non-linear customers for harmonic suppression and high investment pressure for harmonic suppression, customers are reluctant to participate in mitigation, which makes harmonic suppression appear prevarication. As a result, harmonic suppression cannot be carried out smoothly. To solve this problem, a novel premium power supply scheme against harmonic suppression for non-linear park is proposed. Firstly, this paper presents a method for harmonic-suppression needs identification based on super-efficiency interval model to attract customers to participate in harmonic suppression. Secondly, a premium power supply scheme is proposed, which consists of harmonic-suppression needs identification, suppression strategy design and scheme cost allocation. Furthermore, to reasonably allocate the scheme costs among each participant, this paper proposes a data envelopment analysis (DEA) based method considering the influence of both harmonic contribution and harmonic-suppression needs. Finally, case studies are used to verify the effectiveness and correctness of the proposed methods and the scheme.

Premium power supply scheme based on leasing mitigation equipment against voltage sag

Small and medium-sized sensitive users are eager to have premium power supply. The common solution is purchasing mitigation equipment (ME). However, some of they have the financial pressure that cannot afford the mitigation. In order to solve this problem, this paper proposes a premium power supply scheme based on leasing mitigation equipment against voltage sag (PSLM). First, the scheme of PSLM is proposed, which consists of stakeholders, leasing modes and leased property. Second, this paper presents an algorithm of sensitive equipment (SE) trip probability considering effect of ME, to calculate trip probability of SE when it is equipped with ME, which reflects the mitigation effect that is related to profits of scheme. Then technical parameters of ME are optimized by an optimal configuration model, considering tolerance of SE under voltage sag. The cost of the scheme is determined by the optimization of technical parameters of ME. Furthermore, this paper proposes a calculation model of rental of PSLM, to maximize the revenues of both stakeholders. Non-dominated sorting genetic algorithm-II is used to solve the proposed two models. Finally, the effectiveness and feasibility of the proposed PSLM is verified by a case study of a grain oil manufacturer in the south China.

Identification of Customer’s Power Supply Quality Demand and the Strategy of Value-Added Service of Premium Power Supply

The value-added service of premium power supply (VSOPPS) serves as a significant way for power companies to enhance their competitiveness of electricity selling. Premium power supply as a quantitative concept is characterized by power quality indices. However, there exist dramatic differences among customers for their demand in premium power supply. Hence, it is more feasible for utilities to consider customer’s demand categories of premium power supply and provide value-added services according to demand categories. Firstly, the customer’s diversified demand in premium power supply and utility’s service will are investigated. The index system of power quality demand classification is propounded, including customer value indicator and power quality utility indicator. Secondly, based on the index system and the importance degree of all indicators, the identification model of customer’s demand categories of power supply quality is built by combining quantitative and qualitative approaches, and the differentiated VSOPPS package is designed. Ultimately, the cost benefit model of value-added service is put forward, in order to determine the value-added service contents of one customer and calculate the price of value-added service. The reasonability and effectiveness of the proposed approach are testified through the practical case.

Application of User Side Energy Storage System for Power Quality Enhancement of Premium Power Park

User-side battery energy storage systems (UESSs) are a rapidly developing form of energy storage system; however, very little attention is being paid to their application in the power quality enhancement of premium power parks, and their coordination with existing voltage sag mitigation devices. The potential of UESSs has not been fully exploited. Given the above, this paper proposes a hierarchical power supply strategy for premium power parks (PPPs) based on the coordination of UESSs and dynamic voltage restorers (DVR). Firstly, the topology and control strategy of the UESS for voltage sag mitigation are devised. Further, we construct a prototype device, and experimental tests are conducted to verify its effectiveness in voltage sag mitigation. To avoid the negative effects caused by the UESS control mode switching between the voltage sag mitigation mode and the peak-shaving and valley-filling modes—namely, the long control mode switching time and low state of charge (SOC)—a hierarchical power supply strategy is proposed. The basic idea is to supply three levels of power quality service for loads with different sensitivities in PPPs by coordinating UESS with DVR. Several cases are explored to demonstrate the feasibility of the proposed strategy.

A Novel Smart Charging Method to Mitigate Voltage Fluctuation at Fast Charging Stations

The research presented in this paper focuses on the impact of fast charging stations (FCSs) on voltage quality. When the operation of FCSs causes a voltage fluctuation and light flicker, the FCSs may be disconnected, as per the utility general standard practice, which results in financial loss represented by FCS downtime. FCS downtime can be avoided by mitigating voltage fluctuation and light flicker. Flicker mitigation devices that are available in the market are characterized by their high total annual equivalent costs. As an alternative, a novel smart charging method is proposed in this study in order to mitigate both voltage fluctuation and light flicker, whereby customers can select one of three charging services available in fast chargers: premium, regular, or economic charging power. The charging power is selected according to customer priority in relation to time and cost, which offers more flexibility than those currently available in the literature. For instance, the premium power can be selected if the time is more valuable to the customer at the time of arrival at the FCS; in contrast, the regular or economic power are utilized if the cost is more valuable than the time. The results reveal that when an FCS charges a vehicle by an uncontrolled charging method, the FCS violates the flicker tolerance especially when demand for its service is increased by 20% and beyond. In contrast, the flicker limit is not violated when vehicles are charged from an FCS as per the proposed smart charging approach, even when the penetration on the FCS is increased by 50%. The proposed smart charging method offers a compromise solution to satisfy several stakeholders with different interests. Thus, the system operator equipment, FCS investors, nearby customers, and owners of electric vehicles will not be impacted by integrating the FCSs into the distribution networks.

Premium Power Value-Added Service Product Decision-Making Method Based on Multi-Index Two-Sided Matching

With the further reform and development of the electricity retail market in China, the premium power value-added service (PPVS) product is becoming increasingly demanded by high-tech customers. However, the problem of PPVS demand-level matching has not been well studied. How to build an optimal matching and decision-making model which can improve both customers’ and electricity retail companies’ satisfaction degree is an urgent issue. Thus, this paper proposes a decision-making method for PPVS products with multi-index expectation based on two-sided matching. Firstly, a multi-index evaluation system is established from the perspective of customers and electricity retail companies. Secondly, the loss and gain matrices of customers and electricity retail companies are constructed, considering the difference between the expected level (EL) and the actual level (AL) of the evaluation indices. Thirdly, perceived utility (PU) of both customers and electricity retail companies are described with the introduction of elation function and disappointment function, due to different perceptions concerning the matching results under both sides’ evaluation indices. Fourthly, a multi-objective two-sided matching optimization model that aims to maximize the PU of both sides is developed. Finally, an empirical analysis is conducted on three large high-tech electronic-based customers in an industrial park in western Guangdong for demonstrating the effectiveness and rationality of the proposed method.

Configuration strategy of shared mitigation equipment for voltage sag considering the demands of users

It is an effective way to mitigate voltage sag by equipping custom power devices in premium power park (PPP), and the key lies in the balance between technology and economy. This study proposes a method to mitigate voltage sags to meet the needs of different sensitive users in PPP to ensure the mitigation effect and reduce mitigation costs. Firstly, a strategy of shared mitigation equipment (ME) and its operation mode is presented, including the multiple stakeholders, the structure of shared ME, and the scheme of the switch on/off to improve the utilisation rate of ME. Secondly, a sensitive equipment (SE) grouping method is proposed, which is suitable for shared ME strategy, considering the minimum compensation voltage magnitude and the economic loss caused by voltage sag. Meanwhile, this study proposes an assessment method of SE failure probability based on the three-parameter Weibull function to design the capacity of ME reasonably. Thirdly, a multi-objective collaborative optimisation model is established based on economic loss assessment to maximise the net income of investors and users. Finally, the effectiveness of the proposed method has been proved through the case study of two sensitive users in PPP.

Perceived Utility of Premium Power by High-tech Manufacturers

The valuation of premium power based on perceived utility (PU, i.e., perceived effectiveness or satisfaction degree of customers) and their willingness to pay has been researched for years. One of the remaining challenges is the accurate evaluation of PU. PU is the foundation of premium power evaluation, and it is essential for the decision-making process of investments on premium power by high-tech manufacturers (HTMs). This paper presents a framework to effectively evaluate PU. In this framework, factors influencing PU were classified to be quantitative and qualitative. An indication system (IS) was then constructed based on those influencing factors. Finally, PU was evaluated by the IS, considering psychological perception and decision-making behavior of HTMs. The effectiveness of the proposed PU-evaluation framework was demonstrated through field case studies.

Three Phase Inverting Using Pulse Width Modulation Controlled by 6802 Motorola Microprocessor

Different types of voltage sources are available in the market, but the point is how to convert any voltage to our desired waveform? For example; if we have a DC voltage source (like battery or dc generator) and we need to run AC motor (one phase or three phases) or run DC motor with special voltage, or we have an AC source (one phase or three phases) and need to run AC machine with special voltage and special frequency or run DC machine with special voltage. In simple meaning we need a connector between the sources and loads to match between them. But it should pass this conditions; efficiency, mobility, size, weight, range of operation, simple with using and cost.
 This paper focuses on designing and producing a true sinewave inverter that provides premium power which is identical to (or even better than) the power supplied by the utility company with multi output. On this work we will give an explanation for type of inverter depend on output and function for it.

Electrode, Electrolyte and Architecture Assessment for High Power Thin Film Microbatteries

Silicon integrated on-chip energy storage is an attractive goal for hybrid power sources coupled with energy harvesting for ‘Internet of Things’ devices and applications. Typical thin film microbatteries are limited to low power and energy outputs in the 2D planar formats. One of the issues with solid-state thin film microbatteries is the high resistance of the electrolyte which can lead to significant potential drop when powering devices during sensor operation and communication. The ability to provide high currents in a small form factor is a critical need for the development of realistic long life devices. In this work we will describe the use of Comsol finite element simulations to assess electrode materials, appropriate electrolytes and optimised architectures for improved microbattery power outputs. The simulations were of a microbattery stack where non-porous additive-free LiCoO2 is the cathode, lithium metal is the anode and solid-state, polymer, polymer-gel and liquid electrolytes were investigated. The simulations show the material utilisation and overall electrochemical cell behaviour of Li-ion electrode materials at typical and high power rates. Core-shell structures based on nanoarchitectures for electronic contact and active electrode materials have been investigated to improve power delivery for nanoscale active materials and for low conductivity oxide cathodes. The simulations indicate that the implementation of nanoarchitectures such as 3D and 3D core-shell nanoarchitectures when coupled with the appropriate electrolytes and interfacial reactions can have a significant advantage in terms of areal energy and power capabilities compared to a thin-film geometry for a microbattery cell. The deployment of these architectures for microbatteries where area is at a premium and high power capabilities are desirable should result in better performing hybrid energy and less complex power management systems. Acknowledgments The authors would like to acknowledge the financial support from Science Foundation Ireland (SFI) Grant number: 12/IP/1722, Nanomaterials design and fabrication for energy storage. This work is supported in part by a research grant from SFI co-funded by the European Regional Development Fund under Grant Number 13/RC/2077. This work is also supported in part by a research grant from the EU Horizon 2020 work programme – Enables, European Infrastructure Powering the Internet of Things, project number 730957.

Investment Strategy and Multi–Objective Optimization Scheme for Premium Power under the Background of the Opening of Electric Retail Side

With the opening of electric retail side, premium power value-added service has become a main concern for both sensitive customers (SCs) and new electric retail companies (NERCs). However, due to the lack of appropriate investment strategy and optimal premium power investment scheme (PPIS) determination method, the premium power market is difficult to form, thus SCs’ demand for premium power is difficult to meet. Under such condition, how to determine the investment strategy and choose the optimal PPIS are problems that need to be solved. Motivated by this, this paper proposes a multi–participant premium power investment strategy and an optimal PPIS determination method. Suppose that the NERC and the corresponding SCs have already been determined, according to two–sided matching theory, taking SCs’ and NERC’s disappointment–rejoicing psychological perceptions into consideration, premium power perceived utility (PU) (i.e., the perceived effectiveness or satisfaction degree) can be obtained, and a multi-objective optimization model of investment scheme is established. Finally, a field survey has been conducted by the authors on typical high-tech manufacturers (HTMs) located in a High-Tech Park in Sichuan, China. The matching results have been verified by the actual survey. The proposed method is a good way to manage the premium power market.

Premium Power Valuation Method Based on Customer Perception of Utility for High-Technology Manufacturing Customers

Many devices and processes installed at the high-technology manufacturing customer side are very sensitive to voltage sags and short-time interruptions. To meet the customers' requirements for power quality, premium power is needed with a large amount of investment. The investment of premium power depends on the premium power value (PPV) perceived by the customers. One valuation method of PPV based on customers' perceived power utility (PPU) and willingness to pay (WTP) is proposed in this study. The quantitative method of the power utility and the PPU has been studied in detail. Taking customers' loss aversion psychology to economic losses into account, the quantitative assessment methods of the customer WTP and PPV have also been proposed. As a case study, one field investigation to five high-technology manufacturing customers located in one High Technology Park in Western China has been done. With the help of the field-recorded voltage sag data and customer economic losses data over the last 10 years, the proposed method was applied to valuate these five customers. The valuated results compared with investigated results proved that the proposed method is correct, rational, and feasible.

Technical–economic sustainability of premium power parks

This paper evaluates the economic sustainability of different premium power park (PPP) solutions – derived from two prototypes and a theoretical solution – and completes a previous technical analysis of the same PPP solutions. All of these are utility-provided solutions that improve the quality of the electricity delivered at medium voltage (MV) level.We calibrate the study on the potential customers of a PPP, which are MV users sensitive to power quality (PQ) events and badly served. As to PQ events, accidental interruptions and voltage dips are concerned. We evaluate the direct costs caused by PQ events through original and simple cost models developed using different approaches. Even though until today PPPs have not proved to be a winning idea, the results prospect possible future applications of this idea as a consequence of the increasing penetration of dispersed generation, maturation of renewables and developments of energy storage technologies.

Hybrid battery-supercapacitor storage for an electric forklift: a life-cycle cost assessment

Supercapacitors, more properly named electrochemical capacitors (EC), have a great potential in constituting the premium power reserve in a variety of energy- and power-intensive applications in transport and in electricity grids. EC may be used in conjunction with electrochemical storage systems, such as the batteries of various chemistries (lead-acid, sodium-nickel chloride or sodium-sulphur, nickel-metal hydride and even lithium-based systems), in a hybrid configuration where the functions of energy and power can be conveniently separated between the two storage devices and then optimized. Recently, an electric forklift has been commercialized with such a hybrid storage system, without any demonstrated specification of the advantages achievable with this configuration. In this article, the effective technical and economical benefits of this EC integration are theoretically and experimentally evaluated, by means of a conventional electric forklift. The reference vehicle drivetrain is modified by combining a conventional traction lead-acid battery, already used in the vehicle, and a commercial EC. The performances of the modified electric forklift are simulated with already developed vehicle and components models and validated with experimental data. Simulations and electrical tests confirm the functional relationship, expressed in exponential form, between battery lifetime and peak current and demonstrate the technical and economical potentialities of the use of these hybrid configurations, such as the increased efficiency and the prolonged battery life (more than doubling the life of the battery without EC), due to the reduced battery operating stress, and an economical saving (about 30 %), able to compensate initial extra-costs for vehicle modification and battery replacement.

An enhanced premium power park configuration using active power and voltage conditioning devices

In this paper, an enhanced premium power park (PPP) configuration is proposed to effectively mitigate power quality disturbances using a combination of active power and voltage conditioning devices in a spot-configuration-based distribution system. Furthermore, a new coordination algorithm is proposed to achieve full-range coordination between the controllers, thus ensuring the maximum reliability of the proposed configuration. To prove the enhancement of the proposed PPP configuration in terms of improved power quality and investigate the performance of the system under different types of power quality disturbances, several scenarios are simulated using the Matlab/Simulink software.

Short-term Distributed Energy Resource Scheduling for a DC Microgrid

A microgrid is associated with a low voltage distribution power network and inherits small modular generation systems and loads that have certain coordinated functions to provide the solution to supply premium power to remote or specific areas. Similar to conventional power systems, the energy management of distributed generation resources (DERs) is carried out to minimize the operation cost and maximize benefit of installation of DERS in a microgrid. This paper presents the process of implementing the short-term DER scheduling function for a dc microgrid. The optimal scheduling results for two operation modes are then reported.