The paper presents a controller design for grid-connected inverters (GCI) with very small dc-link capacitance that are coupled to the grid via an LCL filter. The usual controller designs would fail and result in instability. The proposed controller h...
Due to the increase in DC load and DC Power generation, the need for DC power system is emerging. Accordingly, FRT (fault ride through) and LVRT (low voltage ride through), which are related regulations for renewable energy sources, have been enacted...
Brushless DC motors are often used as traction motors in electric vehicles due to their high power density and efficiency. The dc-link electrolytic capacitor is the most vulnerable part of the brushless DC motor drive system, and it determines the re...
The current transition towards renewable energies has led to an increased utilization of Photovoltaic (PV) sources and battery energy storage systems to complement the PV panels. To facilitate energy transfer among PVs, batteries, and loads, multiple...
The active power filter (APF) is a popular electrical device to eliminate harmonics in power systems. The rational design and effective control of DC-link capacitor voltage are important for implementing APF functions. In this study, the influences f...
Based on the brushless DC motor system with DC-link small capacitance powered by a single-phase AC power source, a boosting DC-link voltage strategy to reduce the commutation torque ripple of brushless DC motors is proposed in this paper. The control...
Neutral Point Clamped (NPC) converters with n levels are traditionally controlled in such a way that the DC-link capacitors operate at 1/(n − 1) of the total DC-link voltage level. The voltage level across the DC-link capacitors has to be prope...
The DC-link filter which includes a magnetic inductor and a storage capacitor is one of the key parts of adjustable speed drives in the market. It significantly affects the stability, reliability, and power density of the motor-drive system. This pap...
Technological advancements in solar power systems necessitate highly reliable power inverters with a high efficiency and a small size. An LLC resonant converter-based pseudo Direct Current (DC) link inverters offer these qualities to some extent. The...
This paper proposes a new method to reduce the ripple current of the DC-link capacitor in a two-level voltage source inverter (VSI), with a discontinuous pulse-width modulation (DPWM). In real applications, a capacitor block is very bulky, due to the...
The three-phase voltage source inverter (VSI) is de facto standard in power conversion systems. To realize high power density systems, one of the items to be correctly addressed is the design and selection of the dc-link capacitor in relation to the...
The DC-Link capacitor plays a crucial role as far as power density and reliability are concerned: it occupies approximately 40% of the inverter, and causes approximately 30% of its failures. Asymmetrical dual three-phase (ADTP) multiphase arrangement...
Renewable-based sources can be interconnected through power electronic converters and connected with local loads and energy storage devices to form a microgrid. Nowadays, DC microgrids are gaining more popularity due to their higher efficiency and re...
In this paper, we analyzed the output voltage imbalance and the cause of the offset voltage in 3-phase 3-leg inverters by using Millman’s theory. Based on this result, we proposed a voltage imbalance compensation algorithm using the dc offset voltage...
DC-connected parallel inverter systems are gaining popularity in industrial applications. However, such parallel systems generate excess current ripple (harmonics) at the DC-link due to harmonic interactions between the inverters in addition to the h...
This article proposes a simple and reliable damping strategy for wave powerfarm operation of small-scale point-absorber converters. The strategy is based on passiverectification onto a constant DC-link, making it very suitable for grid integration of...
This study addresses the problem of DC-link current pulsations in four-wire AC/DC converters with energy storage operating under unbalanced load conditions. A sensorless compensation algorithm based on AC-side voltage and current measurements is prop...
CHB is a suitable type of topology for synchronous rectifier application which has two or more independent DC loads. Focusing on the individual DC-link capacitor voltage balancing problems caused by asymmetric parameters of independent DC loads, this...
Photovoltaic (PV) energy has been competitive in power generation as an alternative to fossil energy resources over the past decades. The installation of grid-connected solar energy systems is expected to increase rapidly with the fast development of...
E-mobility is an emerging means of transportation, mainly due to the environmental impact of petroleum-based fuel vehicles and oil prices’ peak. However, electric vehicles face several challenges by the nature of technology. Consequently, elect...
This paper presents a method of compensating the AC pulsation appearing in the DC-link of a four-wire AC/DC converter operating with asymmetric output currents. If such a converter is operating with an electrochemical energy storage system, the AC co...
In this paper, an effective power flow control strategy (PFCS) based on the centralized control method and a reliable DC-link voltage (DCV) restoration algorithm for a DC microgrid (DCMG) under grid fault conditions are proposed. Considering the rela...
This paper proposes an analytical formulation-based minimization of DC link current ripples for interleaved parallel inverter systems. Parallel inverter systems find applications in multiple fields. The interleaved superposition of the DC link curren...
Electric propulsion (EP) systems offer considerably more degrees of freedom (DOFs) within the design process of aircraft compared to conventional aircraft engines. This requires large, computationally expensive design space explorations (DSE) with co...
This paper investigates the influence of a constant carrier phase shift on the DC-link capacitor harmonic current of cascaded converters used in fuel-cell and mild-hybrid electric vehicles. In these applications, a DC-DC converter can be adopted betw...
This paper presents a strategy to evaluate the performances of converter stations under the optimized operating points of hybrid AC-DC power systems with a reduced number of DC link variables. Compared to previous works reported with five DC-side con...
This paper presents a new methodology for the design process of DC ripple filters for voltage source converters. It focuses on fast-switching, wide-bandgap-material-based converters. Therefore, a wide frequency range of up to 100 MHz is taken into co...
This paper presents a thorough prediction of DC-link voltage switching ripples in the three-phase four-leg inverters operating in balanced and unbalanced working conditions. The unbalanced modes examined here employ the highest degree of AC current i...
Energy storage systems (ESSs) and active power filters (APFs) are key power electronic technologies for FACTS (Flexible AC Transmission Lines). Battery energy storage has a structure similar to a shunt active power filter, i.e., a storage element and...
The paper presents a methodology for determining the minimum split DC link capacitance for a family of three-phase, three-level grid-connected bidirectional AC-DC converters operating under arbitrary power factor under restriction of DC-only zero-seq...
For permanent magnet synchronous motors (PMSMs) supplied with a voltage source inverter, current control strategies are commonly implemented under the synchronously rotating reference frame. In order to simplify the system structure, three-phase curr...
Large electrolytic capacitors used in grid-connected and stand-alone photovoltaic (PV) applications for power decoupling purposes are unreliable because of their short lifetime. Film capacitors can be used instead of electrolytic capacitors if the en...
The demands of remarkable reliability and high power density of traction systems are becoming more and more rigorous. The conflicting requirements imposed on the control strategy are higher accuracy and higher efficiency over the whole speed range. H...
In this paper, an improved AC-link voltage matching control (IVM) strategy is proposed for the multiport modular multilevel DC transformer (M3DCT), which comprises a single-phase modular multilevel converter (MMC) and a series of cascaded H-bridge un...
DC-link voltage control needs to be achieved for flywheel energy storage systems (FESSs) during discharge. However, load disturbances and model nonlinearity affect the voltage control performance. Therefore, this paper proposes a load-current-compens...
DC link capacitors (DCLCs) are key devices in converters. The relative humidity affects the performance of the elements of a DCLC. Currently, there are relatively few studies on the effect of relative humidity on the electrical characteristics of the...
Electrolytic capacitor-less drive systems have a higher lifespan and reliability. However, the DC-link voltage of ECL drive systems has a sudden change under dynamic conditions, which results in a serious degradation of the drive system performance....
This study presents an effective control strategy for regulating the DC-link voltage in a variable-speed direct-driven (DD) wind energy conversion system (WECS) using a permanent magnet vernier generator (PMVG). To do this, at first, the overall syst...
DC link power supply systems that integrate power electronic converters are increasingly being adopted. In particular, emerging “source–load” systems, in which the DC link interfaces with converters, have attracted increasing resear...
To enhance the robust stability of the dc-link voltage in the photovoltaic (PV) grid-connected system, a modified linear active disturbance rejection control (LADRC)-based regulation strategy is presented in this paper. The proposed control strategy...
The dc-link voltage balance and reactive power equilibrium of the cascaded H-bridge rectifier (CHBR) are the prerequisites for the safe and stable operation of the system. However, the conventional PI (Proportional-Integral) control strategy only put...
This paper presents a novel concept of the DC-AC system with the input voltage boost ability, seven-level output voltage modulation, and the input AC current reduction at the double frequency of the output voltage. The system integrates the NPC full-...
The conventional DC-link type quasi-Z-source inverter has been known as a buck–boost inverter with a low component voltage rating. This paper proposes an active DC-link type quasi-Z-source inverter by adding one active switch and one diode to t...
In some areas, such as Gansu in China and Texas in the USA, lots of wind power bases are located far away from load centers. Transmitting large amounts of wind power to load centers through long transmission lines will lead to wind turbines being int...
The paper presents a particular Pulse Width Modulation (PWM) strategy to reduce the (Direct Current) DC-link capacitor stress for multi-n-phase drives. A multi-n-phase drive is composed of multiple independent systems of n inverter supplying a multi-...
This article examines the impact of a power factor on the behavior of partial DC link voltages in three-phase three-level AC/DC (or DC/AC) converters operating without additional balancing hardware. We consider the case in which the controller utiliz...
Due to the structural aspects of the wind turbine, such as wind shear and tower shadow effects, the output power of the wind turbine has periodic fluctuations, known as 3P fluctuations. These fluctuations can reduce overall power generation and deter...
In order to reduce the switching loss and cost, as well as improve the reliability of the induction motor (IM) drive system, the technology involving the three-phase current reconstruction of 60° discontinuous pulse width modulation (DPWM2) is st...
The DC-link voltage control (DVC) timescale (i.e., the frequency dynamics covering converter outer controls) instabilities in wind generation have gained increased attention recently. This paper presents DVC timescale modeling and stability analysis...
The paper focuses on linearization of split DC link voltage dynamics and balancing their respective average values in three-phase three-level AC/DC converters. It was recently demonstrated that both AC-side current magnitude and operating power facto...
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