The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Due to the defects of the way of the traditional grid power supply, microgrid arises at the historic moment. At present, DC microgrid is an effective solution to integrate renewable energy sources which are DC power supply with DC loads. In allusion to the power unbalance intra-microgrid and the wide fluctuation of DC bus voltage due to unstable output of DC micro resources in DC microgrid, A DC microgrid...
This paper presents a linear programming based solution for an Optimal Placement of Phasor Measurement Units (PMU) problem (OPP) under contingency situations. With the increasing usage of synchrophasors or PMUs for smart grid monitoring and control, the problem of PMU placement has become a major concern due to high installation costs. This paper uses a Linear Programming (ILP) approach to find optimal...
A distributed control method is proposed to handle load sharing among dc microgrids. While microgrids manage the internal load sharing, a higher level controller is required to provide load sharing among microgrids within a cluster. Power transfer between microgrids enables maximum utilization of resources and suppresses stress and aging of the components, which improves the reliability and availability,...
This paper presents a power management concept for DC microgrids where the DC bus voltage is used as the mean of communications between the microgrid components. It is proposed that the energy storage system always controls the DC bus voltage independently of the microgrid mode of operation and sets its value based on power and energy management rules to activate responses from the other components...
Microgrids are low voltage electric distribution grids with modular distributed energy sources and controllable loads. The DC microgrids avoid DC to AC and AC to DC conversion and minimize transmission and distribution losses. Dynamic energy management systems enhance utilization of renewable energy sources and ensure uninterrupted supply of power to critical loads. Like the traditional transmission...
Communication between power converters is vital for high performance DC micro-grids controls. However, for residential DC micro-grid applications, using external communication link would increase the system cost, and reduce the system flexibility and reliability. This paper presents a novel method to enable the conventional DC/DC converters to transmit data via the common DC Bus. With this technology,...
Economic dispatch coordinates the generation across the distribution network while minimizing the overall generational cost. Optimal dispatch is a global optimization problem and, thus, conventionally carried out by a supervisory controller. However, reliability concerns challenge such architectural design as the failure in the central controller or any communication links would hinder the whole system...
Increasing penetration of PV sources in LV grids is introducing new challenges to the quality of voltage. Variability of solar radiation can cause power ramps of up to the nominal power of the plant in one second, which directly induces voltage fluctuations on distribution feeders. To mitigate this impact on power quality, we investigate the introduction of dc micro-grids interfaced to the ac grid...
Alternating Current (AC) is the most common form of power available within buildings. This has historical reasons rooted in large-scale utility generation and distribution of power. With the rapid emergence of local renewables (notably solar) in buildings, the availability of Direct Current (DC) power is becoming more prevalent. In this position paper, we argue that managed power distribution of DC...
Micro-grid architecture design is the basis of the micro-grid construction. It is necessary to follow certain design principles when designing micro-grid architecture, which differs from traditional distribution network designing. This paper describes several micro-grid architecture design principles, taking into consideration in the partition and hierarchy principle, as well as resource utilization...
When DC loads are powered by a DC-microgrid (DCμG) based on a renewable source such as a PV system, energy storage becomes mandatory due to fluctuating nature of the source. Localized DC-energy storage within DC-DC converters could address this requirement. A variation of supercapacitor-assisted low-dropout regulators (SCALDO) could provide localized energy storage with low-noise and fast transient...
It is a normal practice that the DC micro-grid is connected to AC main grid through Grid-connected Voltage Source Converter (G-VSC) for voltage support. Accurate control of DC micro-grid voltage is difficult for G-VSC under unbalanced grid condition as the fundamental positive-sequence component phase information cannot be accurately tracked. Based on analysis of the cause of double-frequency ripple...
The rapid progress of large-scale clean energy accessing to the grid promotes the development of DC grid technologies. HVDC (high voltage direct current) circuit breaker as one of the key equipment of the DC grid has gradually attracted more and more attentions. Direct current is more difficult to be interrupted comparing to alternative current because of without natural zero-crossing, especially...
In this paper, DC power interchange is confirmed to reduce the battery damage by according to the fluctuations in the battery voltage in each micro grid. We investigated various conditions that constructed the DC power interchange system in two micro grids using the DC power flow controller. The experiment examined DC power interchange between two micro grids. As a result, it is able to expect that...
This paper describes the behavior of voltage weak dc microgrids. These are dc microgrids with a relatively small system capacitance. The large amounts of stored energy in the passive component of a network has a considerable effect on the size of the fault currents, control and reliability. The use of a complex control approach to stabilize voltage weak microgrids is a possibility that requires further...
In this paper, authors report on that the peak cut/peak shift operation could reduce the fluctuation range of utility power. Authors have created a small micro grid and are engaged in studying its multifaceted characteristics. In this paper, it has developed the Peak cut / Peak shift operation using tie line power flow control in AC/DC micro grid.
This paper analyses the life-cycle cost of a customer-end inverter that is used in a low voltage DC distribution system. Cost of the losses during the utilization period of the system and the investment cost of the main components is included in the study and the distribution between them is analyzed to determine the dominating cost factors. A sensitivity analysis is carried out to determine how variations...
This paper focuses on the design and control of a stationary energy storage system based on multiple modular high voltage battery modules. The system achieves bi-directional power flow directly from 400V dc grid to the 12V battery modules via a bi-directional dc-dc converter with high conversion ratio as an interface. One merit of such a system is its extensibility and scalability for higher power...
This paper presents a novel GaN transistor based bidirectional isolated DC-DC converter for stationary energy storage device (SESD) for 400V DC microgrid. The improvements achieved in the application includes: first, benefitting from the internal ultra-fast free-wheeling diode, the converter's operation range can be expended to light load conditions (switches operate in hard switching). The light...
The European ENIAC R&D project consortium DC Components and Grid (DCC+G) is developing suitable, highly efficient components and sub systems for 380 VDC grid to show the benefits of DC grid concept on test site in an office environment. The newly developed DC grid components and their integration into a generic system are presented in this paper. The targeted overall efficiency saving compared...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.