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This paper presents the characteristics of the Pulse Width Modulation (PWM) patterns of the Matrix Converter (MC). The various PWM patterns of nine bi-directional switches for the MC can be established. All the combinations of duty cycles with four commutations in three phases during one control period using only input voltage values are derived. The PWM patterns of the derived duty cycles for low...
In this article a new, predictive control method of the AC/DC converter is presented. The method is based on the Direct Power Control algorithm and current error vector minimization criteria. Key assumptions of the predictive DPC-3V algorithms are presented. The correctness of the analysis has been confirmed by laboratory results.
This paper presents a finite control set model predictive strategy for a three-phase, three-level Neutral-Point-Clamped (NPC) inverters with resistive-inductive load (RL-Load). This strategy allows for fast load current control while keeping the balance of the DC-link capacitor voltages. The system performance with a prediction horizon of one sample time and the dynamic response of the system with...
Lots of inverter interfaced micro sources, rectifier loads and three-phase unbalanced loads exist in micro gird, whose character of harmonic source affects power quality seriously. For this reason, based on instantaneous reactive power theory, power decoupling control and current hysteresis control, two kinds of current type inverter control strategy, constant DC voltage control strategy and droop...
This paper investigates the application of the hysteresis current control technique to control the voltage and frequency of a variable speed-constant frequency autonomous DFIG based wind energy system by using Direct Voltage Control method. The DFIG feeds an isolated R-L load. A diode bridge rectifier and a power electronics converter (called rotor side converter) having common dc link is connected...
In this paper Instantaneous Reactive Power (IRP) theory is applied to develop an improved modulation method for Matrix Converters (MCs) operating with unbalanced loads. IRP theory shows that, for unbalanced loading conditions, the instantaneous power contains a constant component and a component that fluctuates at twice the fundamental frequency. In conventional modulation schemes the power fluctuation...
This paper presents a three-phase bidirectional DC-AC converter suitable for operating as an interface between an energy storage system (ESS) based on a battery bank and an isolated microgrid with distributed generation. The converter consists of two stages: a DC-DC stage implemented with a bidirectional half-bridge converter that operates on buck or boost mode (during charge or discharge of the ESS,...
This paper proposes a pulsating torque control with a voltage suppression period, which is effective in reducing energy consumption and suitable for position-dependent load torque applications. The proposed control method is based on extracting the fundamental periodic component as a sinusoidal variation by applying a simplified Fourier transformation algorithm. The energy consumption can be reduced...
A performance comparison study for two proposed DC-bus voltage balancing algorithms is carried out, with a three-level NPC based permanent magnet synchronous machine (PMSM) drive for the electric vehicle propulsion application. Both the control algorithms are able to keep the two DC-link capacitor voltage variation within a tolerance level with wider range of speed and torque variation of the load...
This paper proposes a hexagon voltage manipulating control (HVMC) method for ac motor drives operating at voltage limits. The command output voltage can be simply determined by the torque command and the hexagon voltage boundary in the absence of PI control gains, additional MTPV tracking controllers, and observers for closed-loop control. These attributes reduce the time and effort required for the...
This paper presents an improved direct power control (DPC) to achieve active power ripple minimization for three-phase PWM rectifiers. Conventional switching-table-based DPC (STDPC) selects only one voltage vector from a heuristic switching table for the whole control period, leading to high power ripples at steady state. Contrary to STDPC, the proposed DPC divides the control period into two intervals:...
This paper presents dc-link capacitor voltage balancing at any range of modulation indices utilizing the switching redundancies with minimum loss space vector pulse width modulation (MLSVPWM) algorithm. The five-level diode-clamped converter (DCC) is considered here. By deciding proper switching pattern and their duration jointly, the voltage across each capacitor can be controlled very competently...
Dual sequence current control is the key technique for grid-connected voltage source converter to ensure the performance or fulfill grid requirement under unbalanced grid voltage conditions. In this paper, after reviewing and analyzing the existing dual sequence current controller (DSCC), a simple DSCC is proposed based on double synchronous reference frame (DSRF) without the need of current sequence...
A system is described whereby floating capacitor H-bridge converters are located in each phase between the utility grid and a squirrel cage induction motor. Injecting a series voltage in each phase, the power electronics can be used to control the motor voltage during starting and hence limit the motor starting current to the desired level. The motor voltage can also be used under steady-state operation...
Model Predictive Control (MPC) offers many advantages over more traditional control techniques, such as the ability to avoid cascaded control loops. Unfortunately, as a result of the lack of presence of a modulation strategy, this approach produces spread spectrum harmonics which are difficult to filter effectively. Furthermore, high switching frequencies may be needed because of the limited number...
This article deals with description of the system of converters for electric accumulation. This system is designed by Technical university of Ostrava in Czech Republic as a two stepped system. This article contains design of such a system together with results of experimental measurement and simulations. Also the design of the system for supervisory control is briefly described here.
The present work proposes the Vector Current (CV) analysis, as an adequate method to quantize the performance of linear voltage regulators. We apply this analysis on linear voltage regulators that use a Zener diode as a core element. So, CV measure is a function of the Zener and load currents. CV analysis is carried out on three different regulator circuits, including an improved Feedback-Transistor-Zener...
This paper has researched the vector modulation strategy of three-phase to single-phase matrix converter (3–1 MC) with an active power decoupling capacitor, and focused on asymmetric two-phase current vector modulation of 3–1 MC's virtual inverter. Each work state of 3–1 MC during a switching period is obtained based on the analysis of 3–1 MC's voltage sectors, current sectors and the input current...
Based on the mathematic model of PMSM, two methods of flux-weakening control based on Single Current Regulator are studied in this paper, which are Variable Q-axis Voltage Control (VQVC) and Voltage Angle Control (VAC). By comparing their control theory, it is shown obviously that both two control methods have good robustness, while the means of getting d-axis voltage and q-axis voltage of the two...
To suppress zero-sequence circulating current in parallel operating inverters with common DC power supply, this paper proposes a new strategy based on Dual-carrier SVPWM and proportional resonant (PR) control, which use two opposite active vectors instead of zero vectors to suppress the higher frequency circulating current and reduces the lower frequency circulating current by means of zero-sequence...
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