Comparison between Thyristor Switched Series Capacitors and Thyristor Switched Parallel Capacitors for wind power systems - A Simulation Study

This paper compares by simulation the Thyristor Switched Series Capacitors (TSSC) Circuit with the Thyristor Switched Parallel Capacitors (TSPC) Circuit for wind turbines. The well-known TSSC circuit belongs to the Controlled Series Capacitor (CSC) circuits that have been used in power transmission lines in order to correct the power factor and improve the performance of the electrical system. Such a circuit can be used in wind power systems to improve and maximize the efficiency of a wind turbine. A typical direct-drive wind power system employs variable speed electric generators, but the downside is that systems like that suffer from high inductive reactance. A TSSC circuit, therefore, is able to counteract for any reactive losses, and improve the power factor as well as the efficiency. The main issue with the TSSC circuit is the use of a high number of capacitors that must be connected in series, which can increase the cost and the maintenance of the controller. This paper introduces a novel circuit with different control technique than the TSSC that employs capacitors in parallel configuration. The novel TSPC circuit was simulated in PSPICE and the benefits as well as the drawbacks are described

Mixed Element Networks with Series Capacitors Separated by Unit Elements

In this work, high-pass mixed-element networks with series capacitors separated by unit elements are analyzed. First, the description of the networks via two frequency variables is given. Then, explicit coefficient relations for the descriptive polynomials are derived in terms of the single-variable boundary polynomial coefficients. Finally, the derived relations are used to design a high-pass mixed-element matching network. The series capacitors can be converted to short-ended stubs by means of Richard’s transformation. Thus, the obtained network is suitable for microstrip production.