Space Vector Current Control Research Articles

Vector selection approach‐based hexagonal hysteresis space vector current controller for a three phase diode clamped MLI with capacitor voltage balancing

The purpose of this study is to provide a broad idea about current control scheme and equilibrating voltages in DC-link capacitors of the neutral-point clamped multilevel inverter (NPC-MLI), using an innovative hexagonal space vector hysteresis current control (SVHCC) scheme. The main ideology is to force the literal current vector to reach the reference current vector through an appropriate voltage vector selection sequence. This proposed scheme defines two hexagonal hysteresis bands encompassing the error vector, as a first step. With respect to the error vector location, the selection of the adjacent vector is acted to minimise the error vector. In addition to the error vector selection, the capacitor voltage is also equilibrated by controlling the degree of freedom available in selecting the switching vectors. The SVHCC scheme is intelligent in performing modulation depth dependent selection of switching vectors between the groups namely closest three vector and preferred three vector (PTV). This scheme balances the DC-link capacitors’ voltages within a tolerance limit for any value of modulation index. The proposed scheme is asserted through MATLAB/Simulink software. The superiority of the proposed technique is validated through the 2 kW NPC-MLI supported with SPARTAN III 3AN –XC3S400 field programmable gate array.

A New Five-level Single-phase Inverter Employing a Space Vector Current Control

This article introduces a new five-level single-phase voltage source inverter. The proposed configuration employs two bidirectional switches. Since some switches share the same gate signals, the proposed circuit significantly contributed in reducing the utilized power electronics components, gate drive circuits, and system complexity. A novel space vector current control strategy was employed to maintain the desired number of voltage levels based on load current. With the proper selection of the redundant inverter switching states, the deviation in neutral-point voltage was considerably minimized. The proposed work was simulated and its hardware was manufactured.

A Novel Space-Vector Current Control Method for Commutation Torque Ripple Reduction of Brushless DC Motor Drive

This paper presents a novel space-vector current-control strategy to minimize the torque ripples in brushless DC Motor (BLDC) motor. For BLDC motors, torque ripple, is an important origin of vibration, acoustic noise and speed fluctuation. The current ripple, created due to the stator winding inductance and deviation of back emf, leads to generation of ripple in the torque and prevents the usage of BLDC motor in a precise servo drive system. The paper includes MATLAB/SIMULINK results of conventional, unipolar, bipolar current control algorithms, varying input voltage method and a novel space vector current control method. The comparison of simulation results reveals that the proposed technique is effective in reducing the torque ripple and improves the system performance. The validity and practical applications of the proposed control scheme are verified through the experimental results. The proposed method for torque ripple reduction is validated by reconstructed torque waveforms.

The Direct Pulse Compensation of Dead-time of APF

As the presence of the dead time of switching device, the compensation current of the inverter will have errors, and the compensation effect of active power filter becomes poor. For the fixed switching cycle of space vector current control and symmetrical PWM pulse, proposed a direct pulse compensation method of dead-time .It offsets the impact of dead time by superimposed a square wave on the triangular carrier which compared to the IGBT switching time, the triangular carrier and the square wave have the same frequency, and the amplitude of square wave is equal to dead time. The method is very simple and effective. MATLAB simulation shows that the method basically achieves full compensation of dead time.

A Novel Space-Vector Current Control Based on Circular Hysteresis Areas of a Three-Phase Neutral-Point-Clamped Inverter

This paper presents a novel space-vector current-control strategy for three-phase neutral-point (NP)-clamped inverters. The main task of this control technique is to force the actual current vector to reach the reference current vector. This original strategy consists in defining three circular hysteresis bands around the error vector. Then, according to the location of this error vector, a selection process of the next applied vector is used to minimize the error vector. The NP voltage is balanced by using the redundant inverter switching states. Simple lookup tables are required for area and sector detection, as well as for vector selection. The performance of the proposed control technique is demonstrated through simulation and experimental investigations.

Brushless PM machine drive in electric and hybrid electric vehicles based on the space vector current control

This paper presents a space vector current controller for a brushless permanent magnet motor in electric and hybrid electric vehicles. The proposed current controller selects space vectors based on the sector selection under a three-level hysteresis comparator to decrease the current ripple. The proposed approach can improve the performance of a brushless PM drive such as the average switching frequency and the total harmonic distortion (THD) compared with the conventional hysteresis current control. The experiment is performed first to verify the proposed control. Then, the method is implemented in a hybrid electric vehicle simulation model with standard driving cycles based on the control strategy to evaluate the drive performance in the vehicle system. The experimental and simulation results indicate that the presented control can improve the performance of the brushless PM machine drive.

Comparison of the space vector current controls for shunt active power filters

A new space vector (SV) current control scheme for shunt active power filters (APFs) is introduced first, with a three-level neutral point-clamped voltage source inverter (VSI) as well as a standard two-level VSI. Then, the proposed control is compared with the other SV current control method to evaluate inherent advantages and drawbacks of the control schemes. The proposed control can selectively choose harmonic current components by using a real-time fast Fourier transform to generate the compensation current. The proposed current control utilises a rotating coordinate system, processing the information of the actual position of the grid-voltage SV, which is remarkably important in APF applications, and chooses switching states from the switching table implemented in a field programmable gate array. With the proposed control, the total harmonic distortion (THD) of the compensated grid current, the average switching frequency and switching power loss are significantly reduced. Different SV control strategies, including the proposed method, are compared via simulation and experiment, based on three-level and two-level VSIs.

A practical vector control algorithm for μ-based induction motor drives using a new space vector current controller

In this paper, a very simple vector control algorithm is proposed for /spl mu/-based induction motor drives. The proposed method controls the motor torque directly and linearly to achieve instantaneous torque response without oscillation. The merits of this control method include its simple architecture and obviating the coordinate transformation. At the same time, a new space vector-based current controller is proposed to serve as a quick response torque controller of the proposed drive system. In addition to the current error, information on the current error derivative is further employed so that one can take more advantages of adding the zero voltage vector for reducing the switching frequency. As a result, the efficiency can be greatly increased. It is seen that through integration of the above two parts, the proposed drive system is very simple to implement and has very good performance. >