This paper deals with a crucial aspect in the control of grid-connected power converters, i.e., detection fundamental-frequency positive-sequence component utility voltage under unbalanced and distorted conditions. Specifically, it proposes detector based on new decoupled double synchronous reference frame phase-locked loop (DDSRF-PLL), which completely eliminates errors conventional PLL's (SRF-PLL). is achieved by transforming both positive- negative-sequence components into SRF, from...

This paper analyzes the small-signal impedance of three-phase grid-tied inverters with feedback control and phase-locked loop (PLL) in synchronous reference (d-q) frame. The result unveils an interesting important feature - namely, that its q-q channel behaves as a negative incremental resistor. Moreover, this shows behavior is consequence grid synchronization, where bandwidth PLL determines frequency range resistor behavior, power rating inverter magnitude Advanced PLL, current, strategies...

The solid-state transformer (SST), which has been regarded as one of the 10 most emerging technologies by Massachusetts Institute Technology (MIT) Review in 2010, gained increasing importance future power distribution system. This paper presents a systematical technology review essential for development and application SST state-of-the-art four critical areas are reviewed, including high-voltage devices, high-power high-frequency transformers, ac/ac converter topologies, applications In...

Although it has long been argued that electronic power converters can help improve system controllability, reliability, size, and efficiency, their penetration in systems is still quite low. The often-cited barriers of higher cost lower reliability the are high if electronics used as direct, one-to-one, replacement for existing electromechanical equipment. However, whole distribution were designed a controllable converters, overall could actually improve, currently case at low levels within...

It is well known that single-phase pulse width modulation rectifiers have second-order harmonic currents and corresponding ripple voltages on the dc bus. The low-frequency current normally filtered using a bulk capacitor in bus, which results low power density. However, pursuing high density converter design very important goal aerospace applications. This paper studies methods for reducing energy storage rectifiers. minimum requirement derived independently of specific topology. Based...

Grid synchronization stability issues and subsynchronous oscillations between synchronous generators exist in electrical power systems. Three-phase voltage-source converters (VSCs) are being installed more the grid to improve efficiency or utilize renewable energy sources. The same VSCs also reported analyzed using a small-signal model of phase-locked loops (PLLs). This paper proposes different impedance-based analysis method. proposed method shows that instability VSC system is due negative...

Small-signal stability is of great concern for electrical power systems with a large number regulated converters. In the case dc systems, can be predicted by examining locus described ratio source and load impedances in complex plane per Nyquist criterion. For balanced three-phase ac same impedance-based method applies, which this paper uses synchronous rotating reference (d-q) frame. determined applying generalized criterion (GNC). This approach relies on actual measurement these...

Anticipated widespread usage of new power electronics technologies in electrical energy generation and consumption is expected to provide major efficiency improvements, while the deployment smart grid should improve utilization availability electricity. This paper explores possible relationships between these two trends. Starting from an analysis current trends generation, transport, energy, this contemplates future ac dc electronic distribution system architectures, especially presence...

The emergence of high power converters makes the modern grid more active than it was before. One research directions in this area is solid state transformer, which aims at replacing traditional 50/60 Hz transformer by means frequency isolated AC/AC conversion techniques. This paper presents a systematical technology review essential for development distribution system, especially focusing on following four areas: voltage and devices, transformers, converter topologies, applications system....

This paper presents a novel modulation strategy for neutral-point-clamped converter. overcomes one of the main problems this converter, which is low-frequency voltage oscillation that appears in neutral point under some operating conditions. The proposed can completely remove all points and any kind loads, even unbalanced nonlinear loads. algorithm based on carrier-based pulsewidth modulation. Nevertheless, it generate maximum output-voltage amplitudes are attainable linear modulation, such...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents a comprehensive analysis studying the impact of interleaving on harmonic currents and voltages ac side paralleled three-phase voltage-source converters. The performed considers effects modulation index, pulsewidth-modulation (PWM) schemes, angle. Based analysis, design passive components, such as line inductor electromagnetic interference (EMI) filter, is discussed. results...

The energy performance of various types voltage-source and current-source converters is examined. For fairness completeness, efficiency calculated for three major battleground scenarios. first a low dynamic nonregenerative group applications such as pumps, fans, compressors. This represents 85% high power (2 MW) industrial where savings are usually primary consideration justifying investment. second scenario considers requiring good response regenerative braking. Finally, the third very...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> When the wind power accounts for a large portion of grid power, it may need to help voltage and frequency regulation. This paper investigates permanent-magnet generator with full voltage-source converter in weak-grid mode, where dc-link needs be controlled from side instead side. The energy relationship generator, storage, load is established. An intrinsic right-half-plane zero, together...

This paper presents an experimental parametric study of the parasitic inductance influence on MOSFET switching waveforms. The three most critical stray inductances, namely gate-loop, switching-loop, and common-source inductances have all been studied compared in terms their effect waveform ringing, loss, device stress, electromagnetic interference. Based results obtained, a guideline has established for layout design high-speed circuits.

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper begins with an analysis of the common-mode (CM) noise in a motor drive system. Based on developed CM model, two cancellation techniques, voltage and current cancellation, are discussed. The constraints impedance requirements for these methods investigated. An active filter feedforward technique is proposed, implemented, tested, techniques to improve performance filters explored. It...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents a systematic evaluation approach of three-phase pulsewidth-modulated (PWM) ac–ac converter topologies for high-density applications. All major components and subsystems in are considered the interdependence all constraints design parameters is systematically studied. The key parameters, including switching frequency, modulation scheme, passive values, selected by considering...

A crucial component of grid-connected converters is the phase-locked loop (PLL) control subsystem that tracks grid voltage's frequency and phase angle. Therefore, accurate fast-responding PLLs for protection purposes are required to provide these measurements. This paper proposes a novel feedback mechanism single-phase PLL detectors using estimated Ripple noise appearing in frequency, most commonly second harmonic under phase-lock conditions, reduced or eliminated without use low-pass...

This paper presents a Direct-Quadrature (DQ) rotating frame control method for single phase full-bridge inverters used in small hybrid power systems. A secondary orthogonal imaginary circuit is created to provide the second required transformation; thus DQ model of inverter obtained and its controller designed emulating controls three-phase converters. The proposed attains infinite loop gain coordinate, providing zero steady-state error at fundamental frequency converter. validated through...

Small-signal stability in balanced three-phase systems is typically investigated by means of the generalized Nyquist criterion (GNC) that involves operations on source and load subsystems' impedance matrices. Eigenvalues ratio these matrices should be calculated for judgment. This paper shows a power-electronics-based distributed power system, subsystems can designed as diagonal dominant. Therefore, stability, this case, fully determined scalar ratios formed elements seen across d-axis...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents a new average <formula formulatype="inline"><tex Notation="TeX">$d$</tex></formula>– Notation="TeX">$q$</tex></formula> model and control approach with carrier-based pulsewidth modulation (PWM) implementation for nonregenerative three-phase three-level boost (VIENNA-type) rectifiers. State-space analysis an averaging technique are used to derive the relationship between...

This paper presents a control method to limit the common-mode (CM) circulating current between paralleled three-phase two-level voltage-source converters (VSCs) with discontinuous space-vector pulsewidth modulation (DPWM) and interleaved switching cycles. CM can be separated into two separate components based on their frequency; high-frequency component, close frequency, effectively limited by means of passive components; low-frequency fundamental embodies jumping observed in parallel VSCs....

As the power of wind energy system increases, control their active and reactive becomes increasingly more important from a standpoint given that these are typical frequency voltage parameters. In this paper, family systems with integrated functions transfer, compensation, conversion is proposed. The proposed using solid-state transformer (SST) can effectively suppress fluctuation caused by transient nature without additional compensator and, as such, may enable large penetration farm (WF)...

Environmental concerns and new energy policies are causing systems to shift toward decentralization sustainability. Electricity generation has been historically based on large-scale fossil nuclear sources, even though in the last decade, share of renewables grown significantly. Microgrids (MGs) come as a suitable solution for installation distributed sources low-voltage (LV) grid, where most consumers sparsely located. MGs ease integration generators (DGs) with storage (ESSs) at consumption...

As power electronics infiltrates the electric distribution and conversion systems, stability issues become increasingly significant. The risk of instability due to use constant loads stems from implementation controlled output systems. In three phase converters, these are difficult measure. Although there have been developments in determination system at interfaces stability, a framework perform measurements necessary for such has not fully developed. This paper presents method measure...

A new impedance-based stability criterion was proposed for a grid-tied inverter system based on Norton equivalent circuit of the [18]. As an extension work in [18], this paper shows that using Thévenin representation can lead to same Further, by Middlebrook still be used systems. The link between [18] and original is inverse Nyquist criterion. easier used. Because current feedback controller phase-locked loop introduce poles at origin right-half plane output impedance inverter. These do not...