Three-Level Grid-Connected Inverter Based on Voltage-Oriented Control in Photovoltaic Generation Systems

2013 ◽  
Vol 765-767 ◽  
pp. 2494-2497
Author(s):  
Fang Ping Zhao ◽  
Yong Yang

The paper propose a new control of a three-phase three-level neutral-point-clamped (NPC) pulse width modulated (PWM) inverter in photovoltaic generation systems. The control scheme is mainly based on voltage-oriented control (VOC) with an improved maximum power point (MPP) tracking (MPPT). A cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous dq reference frame using a decoupled feedback control. Furthermore, in order to achieve a unity power factor, the q-axis current reference is set to zero. The experimental results have proven an excellent performance and verified the validity of proposed system.

2013 ◽  
Vol 765-767 ◽  
pp. 2498-2502
Author(s):  
Yong Yang ◽  
Chun Qing Qi ◽  
Ji Suo ◽  
Feng Wen Cao

The paper proposes a new control of a transformerless singe-stage single-phase grid-connected inverter in photovoltaic generation systems. The control scheme is mainly based on voltage-oriented control (VOC) with help of second order Generalized Integrator (SOGI). A cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous dq reference frame using a decoupled feedback control. The simulated results have proven an excellent performance and verified the validity of proposed system.


2012 ◽  
Vol 241-244 ◽  
pp. 636-640
Author(s):  
Wu Wu Tang ◽  
Liang Liang Chen ◽  
Hong Xu Yin ◽  
Hao Dong

This paper developed a mathematical model of three-phase PV grid-connected inverter, and studied the grid-connected current control method based on PI control in synchronous rotating reference frame. Simulation and experimental results from the prototype of 30kW three-phase PV grid-connected inverter proved the correctness and the feasibility of the control strategy, and this grid-connected inverter can operate at the unity power factor state with a nice dynamic performance, and the output current has high sinusoidal and low harmonic content as well as good symmetry.


2012 ◽  
Vol 614-615 ◽  
pp. 1578-1582
Author(s):  
Chun Qing Qi ◽  
Yi Ruan ◽  
Feng Wen Cao

This paper proposes a control strategy,based on the grid voltage oriented vector control (VOC), which makes three-phase inverter control the active and reactive power of grid-connected inverter under the premise of the direct current control. This paper analyzes the principle of three phase photovoltaic grid connected inverter and describes the control structure of the inverter. The control strategy can overcome the deficiencies of the indirect current control scheme. This paper designs the current closed-loop control system, which not only improve the system dynamic response speed and output current waveform quality, while also reduce its sensitivity to parameter changes to improve the robustness of the system. The simulation results show the validity of control strategy proposed.


2019 ◽  
Vol 115 ◽  
pp. 01006
Author(s):  
Amirreza Naderipour ◽  
Zulkurnain Abdul-Malek ◽  
Vigna K. Ramachandaramurthy ◽  
Josep. M. Guerrero

Microgrids (MGs) are developing owing to the rapidly growing distributed power generation systems. The MG controls the flexibility of the network to ensure the requirements of reliability and power quality are satisfied. A typical MG normally consists of dispersed generation resources, which are connected by power electronic inverters, storages, and non-linear loads. This study deals with a compensation control method of a photovoltaic grid-connected inverter using unity power factor (UPF) strategy in MG. In this case, the proposed control method can provide output currents without distortion and with the UPF. Further, it is able to increase the inverter output current to approximately 19 times of the value obtained conventionally. The proposed control method can be applied to three-phase grid interfaced converters such as DG inverters and can also be easily integrated into the conventional control scheme without installation of extra hardware. A theoretical analysis is presented and the performance of the proposed control method for a grid-connected inverter in a MG is evaluated through simulation results.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Mohammad Alshiekh ◽  
Alaa Marouf ◽  
Muhieddin Kubeitari

LCL filter has been widely used in the grid connected inverter, since it is effective in attenuation of the switching frequency harmonics in the inverter. However, the resonance in this filter causes stability problems and must be damped effectively to achieve stability. There are some methods to damp the resonance; one method is passive damping of resonance by adding a series resistor with the filter capacitor, but passive element reduces the inverter efficiency. Other method uses active damping (AD) by adding a proportional control loop of filter capacitor current, but this method needs additional sensor to measure filter capacitor current; moreover, when the control loops are digitally implemented, the computation delay in AD control loop will lead to some difficulties in choosing control parameters and maintaining system stability. This paper presents current control scheme for the grid connected inverter with the LCL filter. The proposed scheme ensures the control of injected current into grid with AD of the resonance in the LCL filter while keeping system stability and eliminating the effect of computation delay of the AD loop. An estimation of filter capacitor current with one step ahead is performed using the discrete time observer based on measuring the injected current. This reduces the cost and increases the robustness of the system. Proportional Resonant (PR) controller is used to control the injected current. Design of control system and choosing its parameters are studied and justified in details to ensure suitable performance with adequate stability margins. Simulation and experimental results show the effectiveness and the robustness of the proposed control scheme.


IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 876-888
Author(s):  
Yuanbin He ◽  
Bangchao Wang ◽  
Xiaogao Xie ◽  
Lei Shen ◽  
Pingliang Zeng

Sign in / Sign up

Export Citation Format

Share Document