Voltage regulation of unit “synchronous generator - combined power flow regulator”

The paper considers alternative technique for regulation of voltage and reactive power of electrical power plant unit; the technique is based on using of combined power flow regulator (CPFR) as coupler of synchronous generator with load. This technique allows of simplifying excitation system of synchronous generator and enhancing reliability of the latter. Software suite MATLAB Simulink is used for analyzing potential of control of such unit in normal modes. At that, synchronous generator is taken with unregulated excitation current, and unit works for active-inductive load. We studied specifics of voltage regulation at unit terminals with CPFR at constant operation mode of generator. The paper presents vector diagrams for initial mode at deactivated CPFR, and as well at activated CPFR at variations of unit mode. Change in unit voltage is achieved with regulation of input amplitude of control system PWM unit by series converter. Results of experiment in software suite were used for construction of set of unit regulation characteristics identifying the range of possible changes in unit voltage. Presented dependences allow of finding necessary parameter values of CPFR that is used in combination with synchronous generator with unregulated excitation system, and is the main means of voltage regulation at load.