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For acquiring of better quality and reducing the harmonic of the high frequency link matrix inverter-HFLMI output, a new envelope curve modulation method is discussed. The method can make the cycle duty of the front stage circuit of the HFLMI's driving signals variable and the HFLMI can gain better output voltage and current by working with de-re -coupling SPWM modulation. The carrier wave for front...
Microgrid is an effective way to integrate the distributed energy resources into the utility networks. Conventionally, the voltage-source inverters in microgrid with sinusoidal current regulation are used in grid-connected mode. In this paper, a two-degree-of-freedom nonsinusoidal current regulation (NCR) is proposed for both the distributed power generation and power quality enhancement. The equivalent...
This paper addresses the low-frequency relative stability problem of the grid-connected voltage source inverter (VSI) based distributed generation (DG) unit in microgrid, in which the conventional active power-frequency (P-ω) and reactive power-voltage (Q-E) droop controllers are commonly used to share the loads. In the sense of the characteristic equation and eigenvalues, the relative stability and...
DC injection suppression is crucial for the transformerless PV systems. IEEE Std.929-2000 specifies that the PV systems shall not inject the dc current greater than 0.5% of the full rated output current. DC injection measurement is not only useful for evaluating whether a transformerless PV system meets IEEE standards, but also for the effective dc suppression with injecting an equal but opposite...
After the working principle and states of a new type of single-phase differential single-stage inverter based on classic BOOST DC/DC converters being analyzed, a topology family of single-phase and three-phase single-stage inverters are be concluded and be brought forward as a “BOOK” inverter name in the same differential working idea. The mathematical characteristics of single-phase and three-phase...
This paper adopts a main circuit structure with back-to-back PWM converter, in which generator-side using direct torque control method, and grid-side adopts three-phase VSR inner current decoupling control based feed forward control algorithms, and this paper proposes an improved MPPT control methods, which can achieves more quickly and effectively tracking the maximum power. Finally, the effectiveness...
This paper discusses vector modulation and sliding mode control for a kind of high frequency link matrix inverter (HFLMC), and presents a kind of De-Re-couple analysis idea to the HFLMC. The De-Re-couple vector condition also has been induced Especially aiming at its non-linear characteristic, this paper proposes a new control strategy called De-Re-couple vector modulation slide mode control and summarized...
Matrix rectifier is evolved from the traditional three phase to three phase matrix converter, and inherits merits of the traditional matrix converter, so it obtains more attention in recent years. According to transformer, matrix rectifier topology falls into the isolated and non-isolated topology. Now the existed modulation strategy mostly focuses on space vector modulation study and is realized...
Sinusoidal signal integrator has the capability of controlling the ac current with zero steady-state error. However, their performances significantly degrade in case of the frequency variations with the steady-state error. So far, no literature has addressed the quantitative analysis of this steady-state error. Therefore, this paper reveals, for the first time, a theoretical guidance to get the accurate...
Taking the high frequency link matrix style three-phase inverter as studying object, combining its topology and the work characteristic, this paper presented the de-re-couple analysis idea. The de-re-couple vector condition also has been induced. Aiming at its non-linear characteristic, this paper proposed a new control strategy called de-re-couple vector slide mode and summarized the design steps...
DC injection is a critical issue in the distributed generation systems according to IEEE Std. 1547-2003. Unfortunately, few literatures discuss this problem. In this paper, a novel control strategy is proposed to achieve zero steady-state DC injection. The proposed idea stems from a well-known fact that a capacitor can block DC component naturally. Generally, this capacitor should be large enough...
Electronically-interfaced converters (EIC) have been widely used in utility network such as Distributed Power Generation Systems (DPGS), Flexible AC Transmission Systems (FACTS), and High Voltage Direct Current (HVDC) Transmission, in which synchronization with the utility network is a key function. In the past decades, phase locked loop (PLL) techniques have been used for the synchronization purpose...
The matrix rectifier described in this paper can realizes three-phase AC voltages to a DC output voltage and can work as a power factor correction converter. The paper presents an SPWM control strategy based on virtual DC link for AC/DC matrix rectifier with high frequency link. The matrix converter in the paper can be equivalent to a virtual rectifier and a virtual inverter. The proposed control...
a novel dual secondary winding and dual power bridge high frequency link (HLF) inverter is discussed in this paper Single-stage power conversion, standard half-bridge connection of devices, soft-switching for all the power devices (ZVS or ZCS), low conduction loss, simple bipolar combined phase-shifted control, and high efficiency are among the salient features of the HLF inverter. The principles...
A data fusion method for single-phase inverter fault diagnosis based on D-S evidential theory and fuzzy logical theory is presented. By measuring the output voltage the two bridge-arms voltage and the temperature of MOSFET, the belief function assignment is obtained, and the fusion belief function assignment is obtained by using D-S rule and fuzzy logic, and fault component is found. By comparing...
In this paper, a small signal model of a novel ZVZCS FB-PWM DC/DC converter is built and analyzed. A double closed loop controller is employed: the inner loop is a PI controller and the outer loop is a fuzzy logic with integrator controller. The novel control strategy improves the performance of the converter greatly, such as stability, control precision and dynamic response. The dramatic feature...
A novel alternating-master-salve control strategy for paralleling inverter is proposed, which merely make use of CAN bus to achieve the high precision of synchronization and fast current-sharing control. Only single interconnection bus is requires and simple arithmetic is used by the proposed scheme. Moreover, the paralleled inverters act as master in turn during each cycle of the output voltage and...
A novel dual secondary winding and dual power bridge high frequency link (HLF) inverter is discussed in this paper. Single-stage power conversion, standard half-bridge connection of devices, soft-switching for all the power devices (ZVS or ZCS), low conduction loss, simple bipolar combined phase-shifted control, and high efficiency are among the salient features of the HLF inverter. The principles...
A single-phase grid-connected inverter system with a novel current control strategy is presented in this paper. The controller consists of a proportional regulator and a new type of resonant regulator. Compared with traditional PI control methods, the P+resonant (PR) control can introduce an infinite gain at the fundamental frequency and hence can achieve zero steady-state error. A more practical...
A novel current-sharing control scheme is presented for redundant parallel inverters. The control scheme employs the share bus which interconnects all the parallel inverters to transfer synchronous signal and average current signal. Current-sharing of all the parallel modules is realized through distributed average circuit. Average current is subtracted from the output current of each parallel inverter...
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