Optimized Non-Dead-Time Control of Inverter with Two-Phase Modulated SVPWM

2012 ◽  
Vol 562-564 ◽  
pp. 1531-1536
Author(s):  
Ming Xing Zhu ◽  
Jing Bo Shi

In the inverter control system, two-phase modulated space vector pulse width modulation (SVPWM) algorithm has the advantages of minimum switch loss and higher utilization of direct current (DC) bus voltage. Non-dead-time control strategy can eliminate the problems of the dead time effects. But the traditional non-dead-time control strategy heavily depends on the current zero-crossing detection, which may cause the output voltage distortion or even a short circuit. Based on the analysis of the reason for the distortion, a new optimized non-dead-time control method is proposed. Two methods for the detection of the overlapping area are enumerated. The conclusions are confirmed by the simulation results with MATLAB/ SIMULINK.

2012 ◽  
Vol 546-547 ◽  
pp. 1050-1055
Author(s):  
Bao Lian Liu ◽  
De Fei Jin

A space vector pulse-width modulation (SVPWM) strategy was developed to solve the failure of traditional SVPWM. A two-phase modulation method is adopted basing on the analyses of traditional SVPWM to select the null switching state in each sector according to the power factor angle. As a result, when the current is crossing zero, the corresponding phase does not commute and dead-time compensation is avoided; and when the current is nearing the peak, the corresponding phase also don’t commute, which leads to lower switching losses. The simulation and experimental results validate that the proposed strategy can effectively improve the current wave, minimize the current distortion and reduce the switching losses. Furthermore, the algorithm is easy to implement.


2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.


2007 ◽  
Vol 17 (10) ◽  
pp. 3571-3575 ◽  
Author(s):  
SATOSHI AKATSU ◽  
HIROYUKI TORIKAI ◽  
TOSHIMICHI SAITO

This paper studies stabilization of low-period unstable periodic orbits (UPOs) in a simplified model of a current mode H-bridge inverter. The switching of the inverter is controlled by pulse-width modulation signal depending on the sampled inductor current. The inverter can exhibit rich nonlinear phenomena including period doubling bifurcation and chaos. Our control method is realized by instantaneous opening of inductor at a zero-crossing moment of an objective UPO and can stabilize the UPO instantaneously as far as the UPO crosses zero in principle. Typical system operations can be confirmed by numerical experiments.


2014 ◽  
Vol 532 ◽  
pp. 62-69
Author(s):  
Yi Chuan Gao ◽  
Guo Chang Liu

A novel actuator controller for greenhouse control system is proposed in this paper. This controller can solve the problems existing in traditional greenhouse control system such as generating electric arc, short circuit risk, lack of communication and smart ability. We adopt five separate magnetic latching relays to control the three-phase motor. In order to prevent generating electric arc in the process of turning off relay, the alternating current zero-crossing detection circuit is designed. In software side, the relay-off task program is running in the real-time operating system, which can ensure turn-off operation at the point of alternating current zero-crossing. In addition, the controller is capable of detecting motors operation parameter and having multiple communication interfaces. Finally, we implement our controller in practice and experimental results meet the design requirements.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2079 ◽  
Author(s):  
Yingjie Wang ◽  
Bo Yang ◽  
Huifang Zuo ◽  
Haiyuan Liu ◽  
Haohao Yan

A modular multilevel converter based high voltage direct current (MMC-HVDC) with DC fault self-clearing is adopted to deal with the DC short-circuit fault. However, the constant power load characteristic of the sub-modules causes capacitor voltages to diverge and the converter to go out of hot standby. To address this problem, a novel DC short-circuit fault ride through strategy is proposed. According to the polarities of grid voltages, the working or blockage of the upper and lower bridge arms is chosen according to six sections to obtain a cascaded star converter. The capacitor voltages of MMC sub-modules are maintained and balanced through the control similar to the cascaded star converter. Moreover, in order not to change zero crossing, a cluster balancing control method by scaling the amplitudes of the modulated waves is proposed to balance the capacitor voltages between phase clusters. The strategy also achieves the DC Bus line-to-line equipotential and no fault current generated. With the switches of two modes (normal operation and fault ride through operation) after the fault is cleared, the power transfer of MMC-HVDC can be recovered quickly. Finally, the effectiveness of the proposed fault ride through strategy is demonstrated on the 21-level MMC-HVDC simulation model in PSCAD/EMTDC.


2012 ◽  
Vol 516-517 ◽  
pp. 1437-1442
Author(s):  
Qiu Rui Zhang ◽  
Bao Ming Ge ◽  
Da Qiang Bi

At present, the rate of energy utilization is low for the transit regenerative braking on urban rail; most of the energy is consumed by the resistance heating. In this paper, a regenerative braking energy injected-grid device is designed, which makes use of regenerative braking energy and effectively reduce the temperature rise caused by the resistance in the tunnel. The paper describes the composition and the design procedure of regenerative braking energy injected-grid device and presents a control strategy of device. The simulation of the single train model verifies that the stability of DC-bus voltage can be maintained and more power can be feedback to the grid by the proposed device when the train is braking. The feasibility and effectiveness of the proposed control method are validated by the experimental results.


Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2195
Author(s):  
Jin-Wook Kang ◽  
Seung-Wook Hyun ◽  
Yong Kan ◽  
Hoon Lee ◽  
Jung-Hyo Lee

This paper proposes a novel pulse width modulation (PWM) for a three-level neutral point clamped (NPC) voltage source inverter (VSI). When the conventional PWM method is used in three-level NPC VSI, dead time is required to prevent a short circuit caused by the operation of complementary devices on the upper and lower arms. However, current distortion is increased because of the dead time and it can also cause a voltage unbalance in the dc-link. To solve this problem, we propose a zero dead-time width modulation (ZDPWM) which does not require dead time used in complementary operation. The proposed technique applies the offset voltage to the space vector pulse width modulation (SVPWM) reference voltage for the same modulation index (MI) as the conventional SVPWM, but any complementary switching operation needs dead time. In addition, the proposed method is divided into four operation sections using the reference voltage and phase current to operate switching devices which flow the current depending on the section. This ZDPWM method is simply implemented by carrier and reference voltage that reduce the current distortion, because complementary operation that needs dead time is not implemented. However, the operation section is delayed due to the sampling delay that occurs during the experiment. Therefore, in this paper, we conduct a modeling of sampling delay to improve the delay of operation section. To verify the principle and feasibility of the proposed ZDPWM method, a simulation and experiment are implemented.


2020 ◽  
Vol 16 (6) ◽  
pp. 155014772092889
Author(s):  
Lei Qi ◽  
Ming Zong ◽  
Shuyi Hao ◽  
Xuejie Wang

The arc generated by breaking the main circuit exacerbates the ablation of the contact, which affects the life of the contactor seriously. By controlling the breaking time of the contactor and making contact break in the optimum time zone are the effective ways to weaken the arc. In this article, the contact movement characteristic is concerned directly in order to control the contact breaking time. A back-to-back double-E alternating current contactor is proposed, and its structural parameters are optimized by particle swarm optimization algorithm. The mathematical model of circuit and magnetic is established. A closed-loop control system based on velocity feedback is proposed. The simulation results show that the designed contactor and the proposed control method are correct, and the actual velocity curve of the contact is consistent with the planned motion curve. It can realize zero-crossing breaking of the main circuit to achieve the effect of no-arc breaking.


2012 ◽  
Vol 466-467 ◽  
pp. 829-833 ◽  
Author(s):  
Kun Mu ◽  
Xiao Bin Mu ◽  
Xue Yu Bao

The mathematical model of Three-phase VoltagePulse Width Modulation (PWM) DC/AC inverter is non-linear, in view of the traditional linear control strategy can not meet the requirements of designing high-performance DC/AC inverter, this paper propose a new nonlinear control strategy for Three-phase Voltage PWM DC/AC inverter called Passivity-based Control. We can alter the inverter model in three-phase abc coordinate to two-phase synchronous rotating dq coordinate for establishing the Euler – Lagrange (EL) energy model for this system, then we also proof this system is strictly passive. We can control the output energy of the system, and we use the approaches of injecting damping and decoupling to improve system performance. Usually, we can use Single Chip Microcomputer or other kinds of computer with this algorithm for our design, this algorithm can be programmed with the computer language, such as C/C++ and assembly language, etc. Simulation results show that passivity-based control method can make this system possess the high-performance of robustness and dynamic.


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