scholarly journals Optimal Predictive Control Method of PWM Rectifiers Based on Artificial Intelligence

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yue Liu ◽  
Guojun Tan

Direct power control (DPC) of pulse width modulation (PWM) is often used to control the instantaneous power of rectifiers. The instantaneous power contains both grid voltage and current information, and its value is not affected by coordinate transformation. It is constant in steady state and reflects the DC control characteristics. However, the switching frequency of traditional DPC is not fixed, the DC voltage has static error, and the system fluctuates greatly. In this work, we introduce the concept of stator flux of the AC motor into the PWM rectifier. Combined with the space vector PWM (SVPWM) technology, we use the virtual flux estimation method to obtain the instantaneous power value, which saves the grid voltage sensor, eliminates the static difference of DC voltage. Furthermore, considering that the neural proportion integral differential (PID) control depends heavily on the initial weight coefficient of the network, we use chaos particle swarm optimization (CPSO) algorithm, which combines the basic PSO algorithm and chaos theory to optimize the initial weight coefficient of neural PID control. In the experiment, the results prove that the performance of the controller can be effectively improved.

Author(s):  
J. Lamterkati ◽  
L. Ouboubker ◽  
M. Khafallah ◽  
A. El afia

<p><span>The study made in this paper concerns the use of the voltage-oriented control (VOC) of three-phase pulse width modulation (PWM) rectifier with constant switching frequency. This control method, called voltage-oriented controlwith space vector modulation (VOC-SVM). The proposed control scheme has been founded on the transformation between stationary (α-β) and and synchronously rotating (d-q) coordinate system, it is based on two cascaded control loops so that a fast inner loop controls the grid current and an external loop DC-link voltage, while the DC-bus voltage is maintained at the desired level and ansured the unity power factor operation. So, the stable state performance and robustness against the load’s disturbance of PWM rectifiers are boths improved. The proposed scheme has been implemented and simulated in MATLAB/Simulink environment. The control system of the VOC-SVM strategy has been built based on dSPACE system with DS1104 controller board. The results obtained show the validity of the model and its control method. Compared with the conventional SPWM method, the VOC-SVM ensures high performance and fast transient response.</span></p>


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Mohsen Ghorbanali Afjeh ◽  
Mojtaba Babaei ◽  
Mohsen Alizadeh Bidgoli ◽  
Amir Ahmarinejad

In this article, a modified single-phase five-level photovoltaic inverter is proposed with a single DC voltage source and six semiconductor switches. Compared with the presented inverters, the introduced topology has the advantage of decreased device count and the first switching frequency for high blocking voltage switches. The proposed PV inverter is implemented without clamping diodes and transformers, which leads to a decrement in size and, consequently, the weight of the converter. In addition, for the proposed topology, space vector pulse width modulation (SVPWM) is deployed that reduces the complexity of multilevel modulation. In order to obtain the optimal output voltage of the inverter, the deadbeat controller is suggested as a rapid dynamic, low-computation digital control method. This closed-loop inverter is implemented in TMS320f28335 digital signal controller to evaluate the performance of the proposed inverter under nonlinear and linear loads. Simulation and laboratory prototype results show that IEC 62040-3 harmonic constraints is met for the proposed photovoltaic inverter in standalone applications.


2017 ◽  
Vol 40 (13) ◽  
pp. 3809-3823 ◽  
Author(s):  
Amit Kumar ◽  
Gopalakrishna Srungavarapu

In this research work, a power quality enhanced grid voltage sensorless deadbeat predictive direct power control (DB-DPC) approach for AC/DC power converters based on latest virtual flux (VF) estimation, DB-DPC and space vector pulse width modulation (SVPWM) is proposed. At first, the grid voltage sensorless technique with switching table based DPC, which is a conventional approach, is discussed and its performance is analyzed under both increase of load as well as decrease of load conditions. Further, the proposed technique performance is also analyzed under the same circumstance and its performance is compared with the traditional method. The proposed technique has numerous advantages over the conventional method such as constant switching frequency, better active and reactive power control, good regulation of dc bus voltage, and enhanced power quality performance. As the proposed approach utilizes VF, DB-PC, and SVPWM techniques, this ensure line voltage sensorless approach, excellent control dynamics and constant switching frequency, respectively. At the end, experimental validation is done to confirm the supremacy of the proposed technique under load varying conditions and has a phenomenal performance under these circumstances.


2019 ◽  
Vol 16 (2) ◽  
pp. 422-427
Author(s):  
S. Karthikeyan ◽  
K. Lakshmi ◽  
S. Sivaranjani ◽  
J. Karthika ◽  
T. Nandhakumar

Multilevel inverters are mainly used in high power and medium voltage applications to reduce the required voltage rating of the power semiconductor switching devices. Nowadays multilevel inverters are also preferred for various applications regardless of the power ratings because they can essentially realize lower harmonics with lower switching frequency and lower electromagnetic interference (EMI). However, it has some disadvantages such as increased number of components, complex Pulse Width Modulation control method, and voltage balancing problem. In this paper a new topology of cascaded multilevel inverter using reduced number of switches is introduced resulting in higher output voltage levels. There era five series connected H-bridges and the DC voltage is given in the ratio n0: n: n3:2n2:10n. The output voltage having 123 levels is obtained (61 positive voltage levels, 61 negative voltage levels and zero voltage levels). Reduced Total Harmonic Distortion (THD) makes them useful for electric vehicle, FACTS and has given option for various power applications. The proposed topology results in reduction of cost and has simplicity of control system. Therefore, the overall cost and complexity are greatly reduced particularly for higher output voltage levels.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5212
Author(s):  
Ho-Jin Kim ◽  
Hyung-Seok Park ◽  
Jang-Mok Kim

In vehicle electrical systems with limited battery power, the output torque and speed of high-speed brushless DC (BLDC) motors can decrease due to unstable and reduced supply voltage or manufacturing errors in the motor back electromotive force (EMF). This paper presents a method that can guarantee the output performance of an inverter through a control algorithm without a separate power supply system and DC-link voltage increase. The proposed control algorithm can increase the output torque and speed of a high-speed BLDC motor by using appropriate selection and change of the inverter’s pulse width modulation (PWM) control method. In this paper, the operation and electrical characteristics of various PWM methods of BLDC motors are analyzed, and the optimal PWM method for improving the control performance of high-speed BLDC motors is presented. In addition, the relationship between the switching frequency, dead time, and voltage utilization was mathematically analyzed. Based on the results of this analysis, the proposed control algorithm automatically changes the PWM switching mode at the point where the output torque and speed need to be extended. The effectiveness and feasibility of the control method proposed in this paper is verified through the experimental results on the designed and manufactured high-speed BLDC motor system for vehicles.


Author(s):  
Yong Li ◽  
Hao Wu ◽  
Qiaorui Si ◽  
Yonggang Liu

The vibration noise of the distributed drive autonomous ground vehicle (AGV) is mainly produced by the inverter-fed brushless DC permanent magnet in-wheel motor (PMIWM). It is necessary to reduce the vibration noise level of the PMIWM driven by pulse width modulation (PWM). A suppression approach of electromagnetic vibration noise for PMIWM is investigated. Firstly, the air gap magnetic field of the inverter-fed PMIWM was analyzed. The electric current harmonics and the unbalanced magnetic force (UMF) were investigated. The natural frequency and noise of the PMIWM were presented. Then, flux-weaken approach was employed to maintain the robustness of the PMIWM when a sudden drop of DC bus voltage. The random switching frequency (RSF) PWM control method based on two state Markov chain is proposed to decrease the amplitude of the harmonics caused by the switching frequency and the multiple switching frequencies. The experimental results show that the RSFPWM can not only effectively reduce the vibration noise and the inverter losses, but also improve the robustness of the PMIWM control system under unpredictable uncertainties.


2014 ◽  
Vol 556-562 ◽  
pp. 2114-2118
Author(s):  
Yi Feng Ni ◽  
Yong Qiang Zhu

The unbalanced grid voltage causes the current harmonics, the fluctuation of the active power in AC side and the fluctuation of the DC voltage. The dual-current loops control strategy can slove those problems. The positive and negative sequence components of grid voltages and currents were calculated based on the symmetrical component method and were used to calculate the instantaneous power in double dq rotate coordinate, which ratate at positive and negative synchronous angular velocity respectively. The dual-current loops control strategy was finally verified in simulation by comparing with the conventional synchronous PI current control. The simulation results show the dual-current loops control strategy is effective on eliminating the fluctuation of the active power in AC side and the fluctuation of the DC voltage.


2011 ◽  
Vol 268-270 ◽  
pp. 1921-1927
Author(s):  
Xi Xiang Zhou ◽  
Jia Sheng Li ◽  
Dan Guo

A control method based on genetic neural network is presented to deal with the nonlinear object of the high-power PS-FB-ZVS PWM DC/DC converter. The control system optimizes the initial weight of the BP neural network and PID parameters tuning on line utilizing the genetic algorithm, which directly controls the object in closed-loop and has solved the problem that the controller network initial weight coefficient influences the control effect, thus, the optimal dynamic and steady state performance of the system is ensured. In the MATLAB environment, the control systems consisting of different controllers are simulated, and the output voltage and output current waveforms are obtained when the system is loaded by experiment. The results show that the controller has strong robustness, fast response speed, and small output voltage fluctuations with load changes.


2020 ◽  
Vol 12 (2) ◽  
pp. 40-46
Author(s):  
Kevin Candra ◽  
Leonardus Heru Pratomo

Five-level inverter is widely used in many industrial applications, for example as a three-phase electric motor drive, PLTS, etc. This inverter works using two separated DC voltage sources in order to form different voltage level. Five-level inverter using one DC voltage source will be more efficient. A DC-DC boost converter on Voltage Doubler type is used in order to solve the problem. The focus of this research is on controlling the DC-DC boost converter on Voltage Doubler type. The switch control method uses a shifted pulse width modulation of 1800. To get a suitable output voltage, an output voltage control system is applied. A proportional and integral type control is implemented using STM32F1038CT microcontroller.  The output voltage controlled DC-DC boost converter is validated through computational simulation with Power Simulator software and as the final step will be implemented on hardware in the laboratory. Based on the simulation and implementation, Voltage-Doubler type of DC-DC boost converter is able to produce the required output voltage, which is two times greater than the conventional DC-DC boost converter output voltage.


2019 ◽  
Vol 8 (4) ◽  
pp. 3628-3632

This paper proposes a 1Φ 31 level inverter using minimum number of switching devices and improved THD level. Multi Carrier based Pulse Width-Modulation (MC-PWM) control method is used to control MOSFET switches in input and load side. In this paper a modified hybrid asymmetrical multilevel inverter using eight numbers of switching devices driven by the multicarrier modulation technique is proposed. This inverter produces thirty one levels at output from four different dc voltage sources. Also THD level is taken into consideration to maintain the power quality. The proposed 31 level inverter is verified through MATLAB simulink.


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