Abstract: The present invention relates to a method for measuring the frequency of phasor of a power system, belonging to the technical field of power systems and automation thereof. A grid-connected photovoltaic generation system is provided with a control module, a data buffer module, an inverter, a sampling module and an analog-to-digital conversion module; a voltage transformer is connected to the grid side of the grid-connected photovoltaic generation system; the voltage transformer is electrically connected to the analog-to-digital conversion module; the analog-to-digital conversion module converts an analog signal sent by the voltage transformer into a digital signal; the sampling module samples the digital signal and transmits the digital signal into the data buffer module; the data buffer module is provided with a plurality of data windows; and the control module receives signals from the data windows.

Abstract: A non-isolated symmetric self-coupling 18-pulse rectifier power supply system comprises a phase-shifting autotransformer, three circuits of output devices, a time sequence controller and a power output end. The phase-shifting autotransformer is provided with three groups of output ends and one group of input ends, and the output device in each circuit comprises a zero-sequence suppression reversing inductor, a three-phase uncontrolled rectifier bridge and a bidirectional switch BUCK converter, which are connected to each other in turn. The time sequence controller is provided with three groups of control ends which are respectively connected to the control end of the bidirectional switch BUCK converter in each circuit. The output end of the bidirectional switch buck converter in each circuit is connected to the power output end.

Abstract: A symmetric-type UPS power system based on a nine-phase phase-shifting autotransformer includes a three-phase AC power input terminal, a three-phase AC power output terminal, a nine-phase phase-shift autotransformer, a synchronized control device for controlling output of a three-phase inverter, a power-frequency isolation transformer and three circuits of output devices; wherein the three-phase AC input terminal of the nine-phase phase-shifting autotransformer is connected to the three-phase AC power input terminal, each circuit of the output devices includes a zero-sequence suppression commutating inductor, a three-phase six-pulse rectifier, a three-phase inverter and a filter inductor which are connected with each other in sequence, each circuit of the zero-sequence suppression commutating inductor is connected to the three-phase AC output terminal of the phase-shifting autotransformer, each circuit of the filter inductor is connected to the input terminal of the power-frequency isolation transformer.

Abstract: A non-isolated symmetric self-coupling 18-pulse rectifier power supply system comprises a phase-shifting autotransformer, three circuits of output devices, a time sequence controller and a power output end. The phase-shifting autotransformer is provided with three groups of output ends and one group of input ends, and the output device in each circuit comprises a zero-sequence suppression reversing inductor, a three-phase uncontrolled rectifier bridge and a bidirectional switch BUCK converter, which are connected to each other in turn. The time sequence controller is provided with three groups of control ends which are respectively connected to the control end of the bidirectional switch BUCK converter in each circuit. The output end of the bidirectional switch buck converter in each circuit is connected to the power output end.

Abstract: A symmetric-type UPS power system based on a nine-phase phase-shifting autotransformer includes a three-phase AC power input terminal, a three-phase AC power output terminal, a nine-phase phase-shift autotransformer, a synchronized control device for controlling output of a three-phase inverter, a power-frequency isolation transformer and three circuits of output devices; wherein the three-phase AC input terminal of the nine-phase phase-shifting autotransformer is connected to the three-phase AC power input terminal, each circuit of the output devices includes a zero-sequence suppression commutating inductor, a three-phase six-pulse rectifier, a three-phase inverter and a filter inductor which are connected with each other in sequence, each circuit of the zero-sequence suppression commutating inductor is connected to the three-phase AC output terminal of the phase-shifting autotransformer, each circuit of the filter inductor is connected to the input terminal of the power-frequency isolation transformer.