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This paper presents the real and reactive power flow control with cascaded multilevel converter (CMC) in the grid. A distribution static compensator (DSTATCOM) is connected at the point of common coupling (PCC) supported from CMC via cascaded transformers. Instantaneous symmetrical component scheme is used to generate the reference current for the compensator. In multilevel inverter the ramp comparison...
Capacitors which are dedicated to microelectronic applications require a lot of characteristics. Indeed they should have a high capacitance but shaped in small sizes, moreover, for some specific applications those capacitors should be flexible to be easily integrated in circuits. A lot of materials are used for this purpose. But, in order to combine all this features, a composite made of three phases...
This paper proposes a compact topology for an integrated PV and energy storage system based on three boost converters and one bidirectional buck-boost converter. One of the boost converters is used for MPPT control, and the other two boost converters are used to implement a boost inverter that can generate sinusoidal waveform. A bidirectional buck-boost converter, to charge and discharge the energy...
Battery energy storage systems (BESS) are expected to increase in the number and capacity because of the increasing share of intermittent renewable energy resources in the electrical grid. Due to the cost and nature of the BESS, they are well suited for the primary reserve to balance load fluctuations in the grid. Power-electronic converters are employed for the power exchange between the transmission...
The effect of different parameters on the electromagnetic repulsion mechanism is analyzed in order to design a high-speed direct current (DC) vacuum switch based on electromagnetic repulsion driving. A two dimensional finite element model is established to analyze the dynamic characteristics of the electromagnetic repulsion mechanism based on rational simplication. Detailed investigations are performed...
The three-phase boost inverter is a differential inverter topology which can provide both boosting and inversion functions in a single power processing stage. If the switching frequency ripple current component is ignored, the DC side current of the three-phase boost inverter contains only a DC component when all three converter legs are identical. However, the capacitance values of the output capacitors...
The size effect of filler particles on the dielectric properties and maximum electric energy density of epoxy-aluminum composites are evaluated. Aluminum particles encapsulated with aluminum oxide layers are used as the fillers to enhance the dielectric constant of the composite and also to maintain the breakdown strength. Experiments were conducted to evaluate the dielectric constant, dissipation...
In some applications, like those for particle accelerators and transfer lines, electromagnet loads operate in cycling mode i.e. absorbing or extracting energy from or to a power source. Built-in energy storage such as electrochemical capacitors can be used whose lifetime is heavily depended on the current ripple and depth of discharge. Moreover, the sizing of this storage element is a trade-off between...
The Modular Multilevel Converter (MMC) has enhanced the feasibility of Multi-Terminal DC grids (MTDC). For controlling the DC bus voltage in the MTDC grids, the droop control is the most promised technique. This paper evaluates the dynamic impact of the way of controlling the MMC on the MTDC grids. Results are compared with a simplified model that highlights the key elements for the dynamic behavior...
The development approach for energy storage systems focuses on optimally sized capacitor modules to reduce peak power and to avoid energy recovery of production machines. Using servo presses as an example, the application of two different energy storage systems in the DC link is practically examined. A simulation model in Matlab/Simulink and a test stand of a servo press are proposed for representing...
This paper presents a modular multilevel Chain-link converter with reduced energy storage requirement by utilizing an active filter storage method at the converter cell level. The active filter circuit and control are analyzed in detail. A comparison with the conventional cell proves the effectiveness of the reactive energy storage reduction.
In this paper, a comparison of the energy storage requirements is performed for the modular multilevel converter (MMC) with half-bridge and full-bridge submodules as well as for the alternate arm converter (AAC). Concerning the AAC, the operational mode with overlap period is taken into account and an analytical relation between the overlap angle and the modulation index is presented. This ensures...
A control structure for the modular multilevel converter motor drive with integrated energy storage system (ESS) is described. The control approach uses the ESS to limit the cell capacitor voltages and to avoid circulating currents in the converter at low output frequencies.
In order to stabilize the grid frequency in case of sudden loss of power generation, an injection of real power is needed. For this, a Static Var Compensator (SVC) can be combined with ultracapacitors, forming a grid frequency stabilizer. To prove the feasibility of this novel combination, the paper shows the realization of a 1 MW class test rig for full-size modules. Single modules are tested using...
Low Voltage DC (LVDC) distribution systems are new promising technologies which can potentially improve the efficiency and controllability of existing LV distribution networks. However, they do introduce new challenges under different fault conditions. Therefore, this paper investigates the performances of an active LVDC distribution network with local solar photovoltaics (PVs) and energy storages...
Three phase ac drives using a dc link typically feature a significant amount of dc energy storage to maintain a stiff dc bus. This paper examines the concept of reducing the size of the dc link capacitor dramatically, to store just enough energy to provide one high frequency switching cycle of output power. The dc bus is no longer stiff and hence the classical sinusoidal pulse width modulation cannot...
This paper describes a “flexbattery” modular battery pack concept that integrates the function of energy storage, active cell balancing, and bidirectional multilevel power conversion. As a result, the flexbattery pack does not have a positive or negative terminal, but terminals that can operate at arbitrary voltage levels, both positive or negative. Since each connection terminal can generate a variable...
This paper proposes a new control method suitable for active power filters to reduce the dc capacitor voltage ripples associated with the third-order harmonic current compensation. The proposed method superimposes a negative-sequence fundamental current on the compensating current to cancel out the active power ripple caused by the third-order harmonic current. As a result, the proposed method has...
For a microgrid with a high penetration level of renewable energy, energy storage use becomes more integral to the system performance due to the stochastic nature of most renewable energy sources. This paper examines the use of droop control of an energy storage source in dc microgrids in order to optimize a global cost function. The approach involves using a multidimensional surface to determine...
Use of renewable sources of energy for charging of electric vehicle(EV) batteries have generated tremendous interest. The use of off-board DC chargers to reduce the weight and increase space inside an electric vehicles has been an important area of interest. Harvesting solar energy to charge electric vehicle batteries can result in large inefficient systems when multiple power conversion stages are...
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