Industrial Electronics
Gholamreza Mohebalizadeh; Hasan Alipour; Leila Mohammadian; Mehran Sabahi
Abstract
To overcome the low output voltage of Renewable Energy Sources (RESs) such as photovoltaic arrays (PVAs) and fuel cells, a new multi-input DC/DC converter is presented in this paper. This converter is based on a combination of modified quadratic buck-boost converters, Switched Inductors (SIs), and Voltage ...
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To overcome the low output voltage of Renewable Energy Sources (RESs) such as photovoltaic arrays (PVAs) and fuel cells, a new multi-input DC/DC converter is presented in this paper. This converter is based on a combination of modified quadratic buck-boost converters, Switched Inductors (SIs), and Voltage Multiplier Modules (VMMs). The high voltage gain can be achieved by adjusting the duty cycle and turn ratio of the coupled inductor of VMM. This structure inherits all the advantages of the SEPIC converter and using a bidirectional input port (in which an Energy Storage System (ESS) can be connected) and several unidirectional input ports. The load power can be flexibly divided among various power sources. Due to the buck-boost characteristics of the presented converter, it is suitable to charge-discharge the ESS. A Coupled Inductor (CI) is used to couple energy from input to the output equipped with the VMM. Moreover, the use of SI reduces the rise time and ripple of the input current. The stability of the proposed converter against momentary changes of VPV and Ro is the main advantage of this converter. Moreover, considering a secondary ESS as Vi instead of PV allows the converter to be active 24 hours a day. In this converter, the use of two ESSs guarantees the supply of the required output power. In addition, two bidirectional input ports prepare the ESSs charging and discharging capabilities. To verify the analysis and feasibilities of the proposed converter, simulation results are presented.
Industrial Electronics
Roya Naderi; Ebrahim Babaei; Mehran Sabahi; Ali Daghigh
Abstract
This work proposes a new multilevel inverter consisting of basic and submultilevel units. The basic unit is made-up of four isolated dc voltage sources, two bidirectional switches and ten unidirectional switches. To increase the number of the output voltage levels, a cascaded architecture based on series ...
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This work proposes a new multilevel inverter consisting of basic and submultilevel units. The basic unit is made-up of four isolated dc voltage sources, two bidirectional switches and ten unidirectional switches. To increase the number of the output voltage levels, a cascaded architecture based on series connection of sub-multilevel is proposed. The proposed inverter utilizes two algorithms to determine the values of dc voltage sources. Number of IGBTs, dc voltage sources, gate driver circuits, variety of dc voltage sources and peak standing voltage on the switches are calculated and their optimization to produce maximum number of levels in output voltage is investigated. To examine advantages of the proposed inverter, the topology is compared with other topologies. The results show superiority of proposed topology over most conventional topologies, in number of circuit components. Finally, to confirm the performance of the proposed multilevel inverter, experimental results of a 25-level inverter prototype are provided.
Industrial Electronics
Taher Ahmadzadeh; Ebrahim Babaei; Mehran Sabahi; Taher Abedinzadeh
Abstract
< p>In power converters, the total harmonic distortion (THD) can be decreased by using two strategies which are filtering and controlling methods. The filtering strategy is indeed costly because of using hardware devices (such as capacitor and inductor). A suitable strategy to control the modern ...
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< p>In power converters, the total harmonic distortion (THD) can be decreased by using two strategies which are filtering and controlling methods. The filtering strategy is indeed costly because of using hardware devices (such as capacitor and inductor). A suitable strategy to control the modern power converters without using the hardware devices is the pulse width modulation (PWM) technique. In this paper, three new PWM control methods based on mathematical equations for various Z-source inverters (ZSIs) are proposed. Controlling the duty cycles of switches is the basic idea of these methods to control the output voltage. The proposed control methods are analyzed under the circumstances of constant input and balanced output voltage (CIBOV) and ripple input and balanced output voltage (RIBOV). The advantages of proposed methods are control of voltage, current and harmonic distortion. Other advantages of these methods are lower value for THD and elimination of low-order harmonics. The correctness operation of the proposed PWM techniques is proved by using the simulation results.
Industrial Electronics
Gholamreza Mohebalizadeh; Hasan Alipour; Leila Mohammadian; Mehran Sabahi
Abstract
Abstract- An Electric Vehicle Battery Charger (EVBC) faces serious challenges as continuous charging voltage ripple, charging speed, input voltage level variations, and its ability to adapt to the Battery State of Charge (BSOC). A proper controller has an important role to prepare all the mentioned above. ...
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Abstract- An Electric Vehicle Battery Charger (EVBC) faces serious challenges as continuous charging voltage ripple, charging speed, input voltage level variations, and its ability to adapt to the Battery State of Charge (BSOC). A proper controller has an important role to prepare all the mentioned above. A nonlinear one such as sliding mode controller (SMC) is eminently suitable for solving these issues. Therefore, an improved SMC, to take control of a DC/DC boost converter as an EVBC, is presented in this work. This proposed controller has a more robust structure in the input voltage significant variations than the other SMCs. Therefore, this provides the capability to apply various kinds of power supplies as input voltages in EVBC stations. The EVBC power and battery voltage/capacity are assumed 14 kW and 400V/60Ah, respectively in this converter. The simulation results in Matlab Simulink verify the controller’s high performance compared with the other SMCs.