scholarly journals Design of a continuously and linearly controlled VSI-based STATCOM for load current balancing purposes

Author(s):  
Faris Asaad Abdulmunem ◽  
Abdulkareem Mokif Obais

In this paper, load current balancing are reviewed in both three-wire and 4-wire systems taking into account linearity, harmonics injection, and control schemes. A linearized static compensator (STATCOM) based on H-bridge voltage source inverter (VSI). The proposed STATCOM is controlled in closed loop mode via equipping it with a new current controller. The DC capacitor voltage of the STATCOM is kept constant without using external energy injection or storage devices via shunting the DC capacitor with a suitable series filter. The simulation results of the current responses of the 220V, 50Hz STATCOM reveal continuous and linear performance during responding to reactive current demands from 123A inductive current to 227A capacitive current. The transition time required for the proposed STATCOM during treatment of a sudden change in reactive current demand from maximum inductive current to maximum capacitive current is less than 40ms. The steady state portions of the STATCOM current responses show pure sinusoids, thus the proposed STATCOM can be promoted as harmonic free static Var compensator. The closed loop continuous mode control and the considerable linearity of the proposed STATCOM promot it as a bipolar susceptance (capacitive and inductive) in applications of load current balancing systems in both three and four wire power systems.

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
M. Janaki ◽  
R. Thirumalaivasan ◽  
Nagesh Prabhu

The static synchronous compensator (STATCOM) is a shunt connected voltage source converter (VSC) based FACTS controller using GTOs employed for reactive power control. A typical application of a STATCOM is for voltage regulation at the midpoint of a long transmission line for the enhancement of power transfer capability and/or reactive power control at the load centre. The PI controller-based reactive current controller can cause oscillatory instability in inductive mode of operation of STATCOM and can be overcome by the nonlinear feedback controller. The transient response of the STATCOM depends on the controller parameters selected. This paper presents a systematic method for controller parameter optimization based on genetic algorithm (GA). The performance of the designed controller is evaluated by transient simulation. It is observed that the STATCOM with optimized controller parameters shows excellent transient response for the step change in the reactive current reference. While the eigenvalue analysis and controller design are based on D-Q model, the transient simulation is based on both D-Q and 3-phase models of STATCOM (which considers switching action of VSC).


2013 ◽  
Vol 321-324 ◽  
pp. 917-920
Author(s):  
Guang Ya Liu ◽  
Xiao Song Li

Three-phase voltage source PWM rectifier generally adopts double closed loop control system. According to the high frequency characteristic of three-phase voltage source PWM rectifier, this paper put forward the setting method of current inner ring regulator and voltage outer ring regulator PI parameter. Finally, it is verified by simulation.


2018 ◽  
Vol 7 (3.8) ◽  
pp. 48
Author(s):  
Goutham Menon ◽  
Mahesh Ratheesh ◽  
Gopikrishna S Menon ◽  
Gautham S ◽  
P Kanakasabapathy

Advancements in power electronic systems has brought forth the modernization of residential power systems exponentially. The interfacing of AC and DC loads with various kinds of resources of energy has been achieved with the help of modern nanogrid architectures. This paper brings into depiction a Tapped Boost derived hybrid converter that can be used to meet the demands of both AC and DC loads having a solitary DC input. A voltage source inverter (VSI) bridge network is used instead of the single switch of a Tapped Boost converter. The VSI bridge has shoot-through protection in the inverter stage increasing its importance for smart power systems. The Tapped Boost derived converter also borrows the advantages provided by the Tapped Boost converter. The paper covers topics like the operation, steady-state analysis and operating modes of the proposed Tapped Boost-DHC. The output and input characteristics has also been tested and verified through simulatio


Author(s):  
Ngoc Thuy Pham

This paper presents a novel structure combining the port-controlled Hamiltonian (PCH) and Backstepping (BS) nonlinear control for the vector control of the six-phase induction motor (SPIM). In this new scheme, to improve the outer loop’s robustness, the BS technique using the integral tracking errors action is proposed in the speed and flux controllers design. The advantage of this proposed control law is not to increase the complexity of differential equation resolution due to being not increased system states numbers. To enhance more the performance of SPIM drives (SPIMD), port-controlled Hamiltonian (PCH) scheme is used in the inner current loop controllers. In this proposed PCH current controller, the stabilization of controller is achieved via system passivity. In that, the interconnection and damping matrix functions of PCH system are shaped so that the physical (Hamiltonian) system structure is preserved at the closed loop level and the closed loop energy function is equal to the difference between the physical energy of the system and the energy supplied by the controller. The proposed control design is based on combination PCH and BS techniques improve significantly performance and robustness. The proposed speed control scheme is validated by Matlab-Simulink software.


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