Cell capacitor voltage control in a parallel hybrid modular multilevel voltage source converter for HVDC applications

2012 ◽  
Author(s):  
E.K. Amankwah ◽  
J.C. Clare ◽  
P.W. Wheeler ◽  
A.J. Watson
Keyword(s):  
Voltage Control ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Parallel Hybrid ◽  
Capacitor Voltage

scholarly journals Modeling and Analyzing the Effect of Frequency Variation on Weak Grid-Connected VSC System Stability in DC Voltage Control Timescale

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4458 ◽  
Author(s):  
Yang ◽  
Yuan
Keyword(s):  
Voltage Control ◽  
System Stability ◽  
Voltage Source ◽  
Frequency Variation ◽  
Voltage Source Converter ◽  
Small Signal ◽  
Small Signal Stability ◽  
Dc Voltage ◽  
Weak Grid ◽  
Dc Voltage Control

The effect of frequency variation on system stability becomes crucial when a voltage source converter (VSC) is connected to a weak grid. However, previous studies lack enough mechanism cognitions of this effect, especially on the stability issues in DC voltage control (DVC) timescale (around 100 ms). Hence, this paper presented a thorough analysis of the effect mechanism of frequency variation on the weak grid-connected VSC system stability in a DVC timescale. Firstly, based on instantaneous power theory, a novel method in which the active/reactive powers are calculated with the time-varying frequency of voltage vectors was proposed. This method could intuitively reflect the effect of frequency variation on the active/reactive powers and could also help reduce the system order to a certain extent. Then, a small-signal model was established based on the motion equation concept, to depict the effect of frequency variation on the weak grid-connected VSC system dynamics. Furthermore, an analytical method was utilized to quantify the effect of frequency variation on the system’s small-signal stability. The quantitative analysis considered the interactions between the DC voltage control, the terminal voltage control, phase-locked loop, and the power network. Finally, case studies were conducted, and simulation results supported the analytical analyses.

Sliding Mode Control Application in Wind Energy Conversion System Using DSTATCOM

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
R. S. Bajpai ◽  
Amarjeet Singh
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Harmonic Distortion ◽  
Voltage Control ◽  
Input Voltage ◽  
Current Control ◽  
Control Mode ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Mode Control

This paper deals with sliding mode control of converter and its application to distributed generation. Sliding mode control is used to control the voltage source converter in voltage or current control mode. Modeling and control of H bridge converter system using sliding mode control is proposed. Easily implemented sliding surfaces provide prominent dynamic characteristics against changes in the load and in the input voltage. Distribution static compensator (DSTATCOM) is used to control the voltage of the bus to which it is connected to a balance sinusoid in respect of the harmonic distortion in supply or load side. A variable wind turbine generator is used to produces a variable DC voltage which is placed as input voltage source to converter of DSTATCOM. A control strategy for grid voltage control using DSTATCOM in voltage control mode has been implemented in respect of the wind variation. The results are validated using PSCAD/EMTDC simulation studies.

scholarly journals Investigation of SSR Characteristics of Hybrid Series Compensated Power System with SSSC

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
R. Thirumalaivasan ◽  
M. Janaki ◽  
Nagesh Prabhu
Keyword(s):  
Power Flow ◽  
Voltage Control ◽  
Transient Simulation ◽  
Control Mode ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Frequency Domain Method ◽  
Combined System ◽  
Modeling And Control ◽  
Q Model

The advent of series FACTS controllers, thyristor controlled series capacitor (TCSC) and static synchronous Series Compensator (SSSC) has made it possible not only for the fast control of power flow in a transmission line, but also for the mitigation of subsynchronous resonance (SSR) in the presence of fixed series capacitors. SSSC is an emerging controller and this paper presents SSR characteristics of a series compensated system with SSSC. The study system is adapted from IEEE first benchmark model (FBM). The active series compensation is provided by a three-level twenty four-pulse SSSC. The modeling and control details of a three level voltage source converter-(VSC)-based SSSC are discussed. The SSR characteristics of the combined system with constant reactive voltage control mode in SSSC has been investigated. It is shown that the constant reactive voltage control of SSSC has the effect of reducing the electrical resonance frequency, which detunes the SSR. The analysis of SSR with SSSC is carried out based on frequency domain method, eigenvalue analysis and transient simulation. While the eigenvalue and damping torque analysis are based on linearizing the D-Q model of SSSC, the transient simulation considers both D-Q and detailed three phase nonlinear system model using switching functions.

Capacitor Voltage Ripple Minimization in Voltage Source Converter for HVDC Applications

2019 ◽  
Author(s):  
Mario Marchesoni ◽  
Massimiliano Passalacqua ◽  
Luis Vaccaro ◽  
Mauro Carpita ◽  
Serge Gavin ◽  
...  
Keyword(s):  
Voltage Source ◽  
Voltage Source Converter ◽  
Voltage Ripple ◽  
Capacitor Voltage
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