Study of Cascade Seven-Level Parallel Active Filter

2012 ◽  
Vol 433-440 ◽  
pp. 6038-6042
Author(s):  
Li Ping Shi ◽  
Zheng Da Wang ◽  
Ya Jing Hu

Multi-level inverter can output high voltage directly and can be connected without transformer, so it is applied more and more widely in high power situation. This paper presents a cascade H bridge seven-level parallel active power filter. This paper analyzes the principle of cascade H bridge multi-level inverter, designs a cascade H bridge seven-level SAPF based on CPS-SPWM, and the principle and the effect are simulated. The simulation results show that this system can compensate load harmonic current.

This paper depicts the methodology of improving power quality at load end is connected with renewable source of energy for power generation. The excessive of power physics devices in distribution system has evolved the matter of power quality. Shunt active power filter (SAPF) acts as a current supply and suppresses the harmonics by introducing the same amount of compensating opposite harmonics component along with common coupling. Simulation design of SAPF based on d-q model is implemented using MATLAB/simulink Toolbox. It explores the modelling of a Proportional Integral (PI) and fuzzy logic controller (FLC) based, SAPF for a 3 wire network to compensate current harmonics fed to a nonlinear load. The proposed model can be validated and its robustness will be checked through the simulation results. Simulation results illustrate that the logic based active filter out performs the PI based shunt active filter.


2018 ◽  
Vol 1 (1) ◽  
pp. 54-66
Author(s):  
Rakan Khalil Antar ◽  
Basil Mohammed Saied ◽  
Rafid Ahmed Khalil

A new control strategy for active power filters is proposed, modeled and implemented in order to improve the power quality of a line commutated converter High voltage DC link. The ability of reactive power and harmonics reductions are generally met by using passive and active power filters. In this paper, modified active power filter with a modified harmonics pulse width modulation algorithm is used to minimize the source harmonics and force the AC supply current to be in the same phase with AC voltage source at both sending and receiving sides of a line commutated converter high voltage DC link. Therefore, it is considered as power factor corrector and harmonics eliminator with random variations in the load current. The modified harmonics pulse width modulation algorithm is applicable for active power filter based on a three-phase five-level and seven-level cascaded H-bridge voltage source inverter. Simulation results show that the suggested modified multilevel active power filters improve total harmonics distortion of both voltage and current with almost unity effective power factor at both AC sides of high voltage DC link. Therefore, modified active power filter is an effective tool for power quality improvement and preferable for line commutated converter high voltage DC link at different load conditions.


2021 ◽  
Vol 17 (1) ◽  
pp. 1-13
Author(s):  
Adala Abdali ◽  
Ali Abdulabbas ◽  
Habeeb Nekad

The multilevel inverter is attracting the specialist in medium and high voltage applications, among its types, the cascade H bridge Multi-Level Inverter (MLI), commonly used for high power and high voltage applications. The main advantage of the conventional cascade (MLI) is generated a large number of output voltage levels but it demands a large number of components that produce complexity in the control circuit, and high cost. Along these lines, this paper presents a brief about the non-conventional cascade multilevel topologies that can produce a high number of output voltage levels with the least components. The non-conventional cascade (MLI) in this paper was built to reduce the number of switches, simplify the circuit configuration, uncomplicated control, and minimize the system cost. Besides, it reduces THD and increases efficiency. Two topologies of non-conventional cascade MLI three phase, the Nine level and Seventeen level are presented. The PWM technique is used to control the switches. The simulation results show a better performance for both topologies. THD, the power loss and the efficiency of the two topologies are calculated and drawn to the different values of the Modulation index (ma).


Author(s):  
Kamel Saleh ◽  
Omar Mahmoud

<span>This paper presents a novel shunt active power filter (SAPF). The power converter that is used in this SAPF is constructed from a four-leg asymmetric multi-level cascaded H-bridge (CHB) inverter that is fed from a photovoltaic source. A three-dimensional space vector modulation (3D-SVPWM) technique is adopted in this work. The multi-level inverter can generate 27-level output with harmonic content is almost zero. In addition to the capability to inject reactive power and mitigating the harmonics, the proposed SAPF has also, the ability to inject real power as it is fed from a PV source. Moreover, it has a fault-tolerant capability that makes the SAPF maintaining its operation under a loss of one leg of the multi-level inverter due to an open-circuit fault without any degradation in the performance. The proposed SAPF is designed and simulated in MATLAB SIMULINK using a single nonlinear load and the results have shown a significant reduction in total harmonics distortion (THD) of the source current under the normal operating condition and post a failure in one phase of the SAPF. Also, similar results are obtained when IEEE 15 bus network is used.</span>


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