Z-source Concept Research Articles

A Generalized Switched Inductor Cell Modular Multilevel Inverter

An interesting feature of a Z-source inverter is to provide buck–boost ability in a single stage. However, this concept is most popular in the conventional inverters. In a few multilevel inverters (MLIs), Z-source is utilized to have higher gain along with retaining the advantages of an MLI such as better electromagnetic interference compatibility, low harmonic distortion, etc. However, the potential of the Z-source concept is not fully exploited in MLIs. To widen the feasibility of the Z-source concept in the MLI, a modular MLI is considered. In this article, a generalized switched inductor cell is selected as a Z-source network for integration, however, other Z-source networks such as quasi-boost network, quasi-switched boost network, two winding coupled inductor network, three winding coupled inductor network, etc., may be used in place of a switched inductor cell. The quantitative and qualitative analysis is done for the proposed converter in both the continuous current mode and discontinuous current mode. The analysis shows that a higher voltage gain can be achieved in the discontinuous current mode as compared to the continuous current mode. To control the proposed converter, two new modulation techniques are proposed, i.e., full shoot through and upper shoot through/lower shoot through. Finally, the proposed converter is validated experimentally in both the modes and for different modulation techniques.

Z–Source Multilevel Inverter Based on Embedded Controller

<p>In this paper Embedded based Z-source multilevel inverter (ZSMLI) is proposed. This work implements a five level cascaded H-bridge Z-source inverter by using embedded control. Switching devices are triggered using embedded controller. In this controller coding is described by using switching table. The presence of Z-source network couples inverter main circuit to the power source that providing special features that can overcome the limitations of VSI (voltage source inverter) and CSI (current source inverter). The Z-source concept can applicable in all dc-ac, dc-dc, ac-dc and ac-ac power conversions. Simulation model of Z-source multilevel inverter based on embedded controller has been built in MATLAB/SIMULINK. The Performance parameters of Z-source MLI such as RMS (root mean square) output voltage, THD (total harmonic distortion) and DC component have been analysed for various inductance (L) and capacitance (C) value.</p>

Z-source inverter fed induction motors

This paper introduces an impedance-source power inverter (ZSI). The Z-source converter uses LC impedance network to supply the main converter circuit to the power source, which delivers the boosting of input voltage that is not feasible in conventional voltage-source inverter (VSI) and current-source inverter (CSI). The Z-source inverter (ZSI) overcomes the intellectual and theoretical difficulties and limitations of the conventional VSI and CSI. It provides a novel power conversion concept. The Z-source concept can be applied to all DC-to-AC, AC-to-DC, AC-to-AC, and DC-to-DC power conversion. To describe the operating principle and control, this paper focuses on a Z-source inverter for DC-AC power conversion fed induction motor drive system. Results are presented to demonstrate the innovative features of ZSI.

Z Source Inverter Using Renewable Energy System

This paper presents a high performance, low cost inverter for Photo voltaic systems based on Z-source concept. Traditional Voltage-source inverter and Current Source Inverter has improved to the new Z-Source Inverter. This impedance source inverter can provide a single stage power conversion concept where as the traditional inverter requires two stage power conversion. A new low cost solar cell powered Z-source inverter system is simulated and the results are compared with the traditional Voltage Source Inverter system. Performance analysis confirms that Z source inverter system is more appropriate for photo voltaic applications. The Z-source concept can be applied to all dc-to-ac, ac-to-dc, ac-to-ac, and dc-to-dc power conversion.

Space-Vector-Modulated Three-Level Inverters With a Single Z-Source Network

The Z-source inverter is a relatively recent converter topology that exhibits both voltage-buck and voltage-boost capability. The Z-source concept can be applied to all dc-to-ac, ac-to-dc, ac-to-ac, and dc-to-dc power conversion whether two-level or multilevel. However, multilevel converters offer many benefits for higher power applications. Previous publications have shown the control of a Z-source neutral point clamped inverter using the carrier-based modulation technique. This paper presents the control of a Z-source neutral point clamped inverter using the space vector modulation technique. This gives a number of benefits, both in terms of implementation and harmonic performance. The adopted approach enables the operation of the Z-source arrangement to be optimized and implemented digitally without introducing any extra commutations. The proposed techniques are demonstrated both in simulation and through experimental results from a prototype converter.

Single-Phase Voltage-Fed Z-Source Matrix Converter

This paper proposes a novel single-phase ac-ac converter topology based on the Z-source concept. The converter provides buck-boost function and plays the role of frequency changer. Compared to the traditional ac-dc-ac converter, it uses fewer devices, realizes direct ac-ac power conversion, and has a simpler circuit structure, so as to have higher efficiency and better circuit characteristics. Compared to the traditional matrix converter, it provides a wider voltage regulation range. The circuit topology, operating principle, control method and simulation results are given in this paper, and the rationality and feasibility is verified.

A Family of Z-Source Matrix Converters

This paper extends the Z-source concept to matrix converters and explores a family of Z-source matrix converters. Their principles and characteristics are analyzed, and a simplified voltage-fed Z-source matrix converter is used as an example to demonstrate its operation, voltage gain versus modulation index, PWM method, boost control, and implementation of the control. Both simulation and experimental results verify operation of the proposed Z-source matrix converter, analytical results, and control method. The Z-source converters can achieve buck and boost operation with reduced number of switches needed, therefore achieving low cost, high efficiency, and reliability, compared to the traditional matrix converters.

Z-source inverter

This paper presents an impedance-source (or impedance-fed) power converter (abbreviated as Z-source converter) and its control method for implementing DC-to-AC, AC-to-DC, AC-to-AC, and DC-to-DC power conversion. The Z-source converter employs a unique impedance network (or circuit) to couple the converter main circuit to the power source, thus providing unique features that cannot be obtained in the traditional voltage-source (or voltage-fed) and current-source (or current-fed) converters where a capacitor and inductor are used, respectively. The Z-source converter overcomes the conceptual and theoretical barriers and limitations of the traditional voltage-source converter (abbreviated as V-source converter) and current-source converter (abbreviated as I-source converter) and provides a novel power conversion concept. The Z-source concept can be applied to all DC-to-AC, AC-to-DC, AC-to-AC, and DC-to-DC power conversion. To describe the operating principle and control, this paper focuses on an example: a Z-source inverter for DC-AC power conversion needed in fuel cell applications. Simulation and experimental results are presented to demonstrate the new features.