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We discuss the conduction modes of conducted disturbance from power-conditioning systems (PCSs), which are used for effective utilization of renewable energy, by measuring the voltage at the DC input and AC output ports of three PCSs. By using three different PCSs, which have different circuit characteristics, as equipment under test and using a voltage probe and artificial mains network as the measurement...
In this paper, an analytical expression for the DC bus harmonics on the input capacitor, caused by a three phase pulse width modulation (PWM) inverter of a high speed motor drive system, is derived. As the result, we found that the parasitic line inductance between the battery and the input capacitor, and the input capacitor are indirectly proportional. We can achieve the calculation method of the...
Recently renewable energy has attracted a lot of attention and solar power generation systems and wind power generation systems are widely used as public eco-awareness increases. Generally inverters are used in such power generation systems. They need high efficiency. Multi-level technique improves efficiency of inverters.
This study evaluated power generation characteristics of sixteen different types of Photovoltaic (PV) systems in “F Solar Research Park”. As a result, the performance ratio of crystalline silicon and CIS PV systems were higher during winter months and decreased in summer whereas amorphous PV systems were reverse seasonal characteristics due to the light induced degradation and annealing effect. This...
In this paper, splitting of peak switch voltage by series connected transistors in the class E inverter is proposed. In this method, peak switch voltage of class E inverter is reduced to half of conventional because shunt capacitor voltage is divided by two switches. Key feature of this method is that drive signal source of each switch can be grounded. Namely, transformer is not required in this method...
Mashhad Electric Energy Distribution Company (MEEDC) has designed and implemented the first local micro-grid in Mashhad which is called “MehrSun”. This article presents the performance analysis and result assessment of Mehrsun after working for one year. Different micro-grid elements and the connections with local power network are explained and the level of home automation which is implemented for...
In this paper, 3-level Active NPC inverter of predictive thermal modeling controls losses through the predictive thermal modeling. In the advantage of conventional 3-Level NPC, the generated thermal in each switch is unbalanced. Also, utilization of designed system has decreased. Thus, in order to compensate, 3-Level Active NPC inverter can distribute switch loss in accordance with operation of active...
This paper presents a harmonic current injection control for active islanding detection of grid-connected inverters. A standardized islanding detection method called frequency feedback method with step reactive power injection is used in the inverter system for islanding detection. After an islanding event, this method measures the change of voltage harmonic distortion and injects reactive power to...
To reduce the life cycle cost of solar power plants, high conversion efficiency for inverters is necessary. The advantages of SiC MOSFETs include not only lower conduction loss but also the ability of high-speed switching. Lower switching loss is derived from high-speed switching. Especially with SiC MOSFETs, the tail current and switching recovery loss can be drastically reduced compared with Si...
Telecommunications is a rapidly growing field in global technology and it has a significant social, cultural, and economic impact on modern society. As such, ensuring reliability of these systems should be highly prioritized and involve sophisticated standards. Due to the highly sensitive nature of Telecom loads, it is vital that failure of the utility power be detected quickly. In this paper, Slip...
In recent years, in overseas, particularly Asian countries, demand of UPS is growing up, the expansion of three-phase four-wire type UPS of the line-up for the Asian countries has come to be expected in our company. In this paper, based on the new way of thinking, we report that we have developed a three-phase four-wire type UPS in a short development period by applying the single-phase UPS that we...
The present study discuss about restructuring in lighting systems in order to improve load leveling. The aim of this paper is to perform an economic assessment of utilizing DC lighting instead of AC lighting in presence of photovoltaic energy systems. For each scenario, the amount of luminous flux (lm) provided by the lighting fixtures is constant based on requirements for office spaces. The current...
A small modular unit for a power converter system with long lifetime DC-link capacitors is proposed. To reduce the ripple current stress of DC-link capacitors and to improve their lifetime by limiting temperature rises, low phase-to-phase-impedance busbars are selected. Consequently, in a power converter system whose size is 101 L, operating at a rated power of 100 kVA, DC-link capacitors achieve...
In this paper, power losses of 3-level NPC inverter (3LNPCI) and 3-level T-type inverter (3LTI) are classified and calculated according to the switching states. The conduction loss depends on modulation index (MI) and power factor (PF), whereas the switching loss depends on switching frequency, so the power loss analyses have been done at the different operating points of MI, PF, and switching frequency...
When a emergency occurs in the solar power generating, to confirm that there is a possibility of arcing. As long as there is solar radiation, solar power generation keeps supplying the electric power. Therefore if the arc occurs, there is a risk of fire. However, protection device for protecting a direct current system side was not present. We have developed a protective device for performing emergency...
This paper proposes a design method of a common-mode current feedback type EMC filter in an interconnection system. First, the relationship between the switching frequency of the PWM inverter, the common-mode feedback current and the volume of the filter reactor is theoretically estimated. Moreover, the switching frequency and the current capacity of switching devices which are necessary in order...
A current sharing method considering battery state of charge(SOC) for multi-module uninterruptable power supply(UPS) system is proposed. Modularized UPS system consists of a single master module and multi slave modules. A master module performs output voltage control and distributes current commands to slave modules. The current commands are generated by using the proposed current sharing algorithm...
The power conditioning system (PCS) is widely used as a grid connected inverter to keep output constant. A novel power conditioning system (PCS) using a circuit of modular multi-level converter (MMC) construction is investigated. The feature of the system is that output voltage becomes multilevel for low distortion and circuit has an energy storage system such as a battery or an electric double layer...
This paper proposes Z-source with voltage multiplication inverter for grid connected Photovoltaic (PV) application. The proposed scheme has two-stage. The first stage consists of Z-source with voltage multiplication converter. The proposed converter has high gain compared to other transformer less topologies and reduced voltage stress on the switch. The second stage assembled from five switch inverter...
This paper proposes a new design and implementation of a single stage three-phase multi-level inverter (MLI). The suggested inverter is modular type and can be generalized by connecting the basic modular cells in series configuration. In addition, it can be operated with symmetrical/asymmetrical Dc-voltage sources. The proposed MLI is successfully modulated using sinusoidal pulse width modulation...
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