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A control strategy for a three-phase grid connected inverter with LCL filter based on Lyapunov energy function during unbalanced grid conditions is presented in this paper. To reduce complexity and number of variables the control strategy is accomplished in a stationary two phase reference frame. Dual second-order generalized integrator structure (DSOGI) is utilized to extract the positive and negative...
This article presents the simulation and harmonic analysis of a charging station model developed in “Modeling and protection of electric vehicle charging station”, which was adapted with the electrical parameters of the distribution system of Cuenca city, with The purpose of quantifying the amount of harmonics that this type of stations can produce in the network. The simulation resulted, that the...
With regard to the pulse width modulation (PWM) of seven-phase motor system if the three-phase space vector pulse width modulation (SVPWM) is simply extended to the seven phase motor system that is the seven phase of the traditional SVPWM it will produce a great harmonic current. In order to restrain the harmonic content of phase current the voltage vector synthesized in the 3rd harmonic subspace...
In photovoltaic (PV) systems, module level power electronics has focused a lot of attention in the last years. The microinverter, also known as AC module, has shown to be an interesting solution. For this purpose, PV microinverter architectures with pseudo DC-link consisting in a DC-DC converter followed by an unfolding inverter have been analyzed as good alternatives. This paper proposes a new push-pull...
This paper presents a time-delayed model predictive control for power converters used in vehicle to grid and grid to vehicle systems. Finite-based model predictive control has proven to be an alternate digital control method for power converters. However, there are some real-time implementation issues, including specifically time delay, that have to be addressed in order to achieve the system reliability...
In this paper, a virtual synchronous generator with photovoltaic energy storage hybrid system (VSG-PV) is adopted. VSG-PV can not only output the maximum power of photovoltaic, but also can maintain a stable voltage and frequency of the point of common coupling when system worked in the island model comparing to the conventional photovoltaic generation system. The small signal model of the hybrid...
In this paper, a new quasi Z-source inverter based on new capacitor basic units (CAQZSI) is proposed. It is possible to develop the proposed topology by using n numbers of the basic units that is one of the main advantages of the proposed CAQZSI. The boost factor equation, voltage and current equations of the capacitors, diodes and inductors are obtained for the proposed topology and developed CAQZSI...
An increased deployment of distributed generation in recent years has contributed to creation of meshed power networks usually seen as a way to improve power flow management capability. Also, power electronics converters have been commonly used to interface distributed resources to the grid, yet their impact on the network stability has not been sufficiently explored. In this paper the stability of...
The increasing penetration of grid-connected RES systems, advanced control algorithms have been developed to operate under grid faults and fulfill strict requirements of the grid codes. In order to overcome this, the current controller performance is critical considering it as the inner control loop of any grid-connected RES system. Based on the resonant control concept, this paper presents a modified...
In this paper, an improved grid voltage modulated control (GVM) with power compensation is proposed for grid-connected voltage inverters when the grid voltage is unbalanced. The objective of the proposed control is to remove the power ripple and to improve current quality. Three power compensation objectives are selected to eliminate the negative sequence components of currents. The modified GVM method...
Parallel Neutral-Point Clamped (NPC) inverters are commonly employed in medium voltage high power applications, such as wind energy system, smart transformer, and power conditioners. In literature, it is shown that the Phase Disposition modulation (PD) strategy provides better performance in terms of harmonic profile and current ripple for single NPC application. Therefore, the PD has been commonly...
Nowadays capacity of the photovoltaic systems in the grid is remarkable and provides a major part of energy in the grid. Therefore, an abruption of these systems from the grid can create a damage to the grid. Unlike in the past that PV systems disconnected from the grid when a voltage drop occurred, nowadays these systems should have Low Voltage Ride-Through (LVRT) capability. The PV system should...
In this paper, a current control is studied based on D-Σ digital control to improve the grid-connected performance for a three-level T-type inverter. The control principle is analyzed in accordance with the single-phase equivalent circuit of the three-level T-type inverter. The influence of the neutral-point voltage on both output current error and modulation signal is discussed, and the relationship...
On the basis of establishing mathematical model of induction machine, the simplifying assumption of two-dimensional plane finite element model was proposed, and Dirichlet and main boundary conditions were defined. The speed governing of induction machine was realized using back-to-back voltage-fed frequency converter. The continuous output direct voltage value of three-phase non-controlled rectifier...
The traditional rectifier grid will bring a large number of harmonics and reactive voltage harmonic pollution, in order to reduce the grid side voltage harmonic component, this paper proposes a kind of three-phase photovoltaic grid-connected inverter based on grid voltage vector oriented dual closed loop control method. The SVPWM technology is used to realize the double closed-loop control model of...
In this paper, a kind of networked control of power-sharing for inverter parallel operation is presented. To increase the participation of communication and improve the system performance, both autonomous mode and master-slave of communication mode in networked control are investigated. Nevertheless, communication actions may bring some unpredictable outcome due to the negative factors such as time-delay...
This paper presents an approach for upgrading droop control aimed to improve its performance when used for two parallel inverters. The proposed control ensures equal voltage for the two inverters when different power flowing through them which guarantee zero current circulation. To fulfill the voltage regulation, the second inverter (slave) regulates its voltage to follow the master inverter reference...
This paper proposes a Current Deadbeat Control (DBC) algorithm for a three-phase 9-cells qZS based Cascaded H-Bridge (CHB) inverter to ensure grid current supply with low THD. The studied topology is considered as a single-stage DC/AC topology having the capability of boosting the DC input voltage with high-quality multilevel AC voltage, independent DC-link voltage compensation, and control of the...
As the large-scale integration of photovoltaic (PV) power station, a higher requirement is put forward by power grid analysis on the accuracy of PV station model. For the model of photovoltaic system is complex, and it requires solving large-scale model equation, which is not conductive for simulation and big data analysis when a large-scale PV power station connected to grid. This paper focuses on...
In this paper, the relationship between real and reactive power sharing in islanded microgrid considering the complex impedance effect is analyzed. It is determined that traditional droop control has drawbacks in achieving accurate power sharing caused by the mismatched feeder line effect. In order to enhance the power sharing accuracy, an adaptive droop control using virtual impedance for islanded...
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