Fast and reliable fault diagnosis is essential for induction motor (IM) drive systems with high-reliability requirements. In this article, we propose a robust open-switch fault-diagnosis method based on the common-mode voltages of inverter in IM-drive systems. This makes full use characteristics voltages. First, calculated (CCMVs) are equal to each other under normal operating conditions CCMVs represent behaviors conditions. Second, average voltage degree freedom modulation inverter. Based...

In single-phase voltage source inverters under a weak grid, the frequency coupling, caused by asymmetrical system structure, poses challenge to modeling and controller design. this article, coupling suppression control strategy is presented, where all components in current reference are eliminated. As result, grid-tied inverter directly modeled as simple single-input single-output (SISO) admittance rather than complicated multiple-input multiple-output matrix. The SISO model simple, compact,...

This article proposed a current-sensorless control scheme for the single-phase uninterruptible power supply (UPS) inverter under nonlinear load. Different from existing literature, information of load current can be obtained by designed adaptive laws. It is meaningful system's security and reliability. Under assumption that periodic ideal-independent source, Fourier series in trigonometric form expanded to model unknown disturbance current. The observer-based feedback rate update laws are...

Due to no dc-link energy storage element in the matrix converter (MC), its input and output performances are highly sensitive unbalanced grid conditions. In order mitigate adverse effects of voltages, this paper proposes a simple effective control strategy based on finite-control set model predictive (FCS-MPC). case, an extended instantaneous power theory is adapted generate source current references. As result, both sinusoidal currents balanced ensured. Besides, complicated positive...

Lithium-ion battery-based hybrid energy storage systems (ESSs) have been widely applied in various fields. Bidirectional DC/DC converters, crucial interfaces linking batteries and DC buses, serve as critical actuators for tasks such bus regulation, on-line battery diagnosis, health-conscious management strategy, fault tolerant control. Despite their importance, the control of bidirectional converters ESSs has rarely independently discussed. Their control-related works are usually carried out...

This letter presents a new space vector modulation strategy adopting zero vectors to achieve common-mode current (CMC) reduction for indirect matrix converter (IMC). By substituting conventional by vectors, the impedance of loop increases, which contributes CMC reduction. Thus, IMC system with proposed method alleviates adverse effects ac drives. Moreover, additional hardware and complex commutation process are not required. Experiments conducted verify effectiveness method.

In this article, a resistance-emulating control strategy without grid voltage sensors is proposed for three-phase source rectifiers under unbalanced conditions. It consists of angle estimator, coordinate correction, resistance-emulating, common-mode resistance (CMR) and the differential-mode (DMR) regulation, extended state observer, other critical steps. scheme, CMR regulates average power, DMR controls ripple power caused by supplies. Three different objectives including constant active...

Due to the nonlinear time-periodic nature, precise impedance modeling of power-converter-based single-phase ac systems is complex. Small-signal for with a fixed operating point easy, but extension same procedure trajectory still challenging. In this article, recursive single-input single-output (SISO) framework rectifiers presented, which can greatly simplify both and resulting model. A general linear-time periodic method proposed by extending invariant method, where frequency-coupling...

The ripple power with double grid frequency inherently exists in a single-phase current source rectifier. To achieve the constant dc-link current, an alternative way is to use LC resonator tuned at 100 Hz block power. However, this method requires large passive components, which will degrade density and even reliability. What worse, decoupling performance be deteriorated when parameter drifts happen. In letter, control strategy based on emulating output voltage characteristic of proposed....

This article proposes an adaptive power decoupling control strategy for a single-phase rectifier with unbalanced split-capacitor circuit. Since capacitance mismatch estimator is integrated into the strategy, impact of eliminated. Meanwhile, can provide auxiliary online monitor health split capacitors. Moreover, mechanism capacitor voltages self-balance explained. Finally, experiments are conducted to verify effectiveness proposed method.

A transformer-less dynamic voltage restorer (DVR) with bipolar gain capability is proposed in this study. The DVR formed by a three-leg ac/ac converter its output capacitor series the transmission line. Since energy used for compensation obtained from grid, long-time disturbances can be compensated without using bulky storage elements. As result, has features of compact structure, light weight, and low cost. Moreover, it also high reliability as commutation problem avoided adopting...

DC-link voltage pulsation is a technical challenge for grid-connected three-phase source rectifiers (VSRs) under unbalanced grids. To suppress ripples arising from grids, frequency-divided resistance-emulating control strategy proposed in this paper. According to the idea, loop consists of two parts: one dedicated regulating average and other focused on suppressing pulsating voltage. The inner synchronized based approach. offers following advantages: 1) grid sensors are eliminated; 2)...

Vienna rectifier is a typical three‐level with complicated operating constraints. Also, the constraints pose challenge for designing controllers good dynamic performance. As predictive control at dealing constraints, an optimal switching sequence model (OSS‐MPC) strategy three‐phase proposed. A proportional–integral controller designed to regulate dc‐link voltage. improved OSS‐MPC method utilised input currents. Compared conventional finite set control, it has extra advantages of...

For the digitally controlled buck converters, nonlinearity and time periodicity, caused by pulsewidth modulator (PWM) sample hold, make accurate frequency-domain analysis intractable. In this article, based on harmonic transfer function (HTF) approach, a precise small-signal continuous-time modeling for Buck converter operating in continuous-conduction mode (CCM) under constant-frequency voltage-mode control is presented. The sideband components closed-loop are embedded model. Thus, model...

Multi-VSG grid-connected system faces the risk of power, frequency and voltage oscillation that threatens security stability system. This article builds a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P/Q</i> - xmlns:xlink="http://www.w3.org/1999/xlink">ω/V</i> "admittance" model multi-VSG systems analyzes The proposed reveals interaction between different VSGs depicts active/reactive power frequency/voltage response under input reference...

Power oscillation is a technical challenge for the grid-connected three-phase current source rectifiers (3ph-CSRs) under unbalanced grid voltage conditions. To manipulate instantaneous power adapted to different requirements conditions, conductance emulating control method proposed in this brief. The constructs fictitious pair with two individually adaptable parameters. One parameter regulates distribution of oscillating between active and reactive power, another controls average power....

Frequency-domain modeling is an effective technique in the dynamic analysis of power electronic converters-based systems. In this paper, a unified single-input single-output (SISO) loop gain for three-phase grid-tied voltage source converters (VSCs) under both symmetric and asymmetric AC grids presented, which facilitates physical measurement stability analysis. Based on linear-time-periodic (LTP) technique, harmonic admittance model VSC developed stationary ( <italic...

This letter proposes an algebraic modulation strategy for the three-level neutral-point-clamped converters. The duty-cycle-assignment problem is first transformed into algebraic-solution problem. Then, according to theory, general solution of matrix obtained. By properly designing free parameters in matrix, various neutral-point voltage (NPV) balancing methods can be constructed conveniently. In addition, NPV balance easily realized without additional control effort. Compared existing...

According to different partitioning styles, there exist impedance-based stability analysis methods for complex systems such as voltage source converter (VSC)-based high-voltage direct current (HVDC) systems. Thus, the determination of method is importance in analysis. However, how partition a system not paid much attention past. In this paper, problems are revisited and set practical principles proposed. Based on principles, VSC-HVDC partitioned into five parts, satisfying simplicity...

In this article, an algebraic modulation scheme is tailored for the three-phase current source converter, featuring easy implementation, low computation, and flexibility. The general form of vector first obtained by solving nonhomogeneous equations converter synthesis. duty-cycle constraints are satisfied designing free variables in vector. Then, switching sequence flexibly arranged according to performance requirement. Based on scheme, two optimized strategies further developed, where one...

This article presents a general impedance-emulating control method for single-phase rectifiers. To repress the harmonic currents due to distorted input supplies, impedance based on concept of repetitive is emulated. realize unity power factor, negative inductor-emulating technique extremum-seeking scheme applied. In this method, voltage sensor not needed, so cost reduced and reliability improved. The experiments are conducted verify effectiveness proposed method.