University of Macau

Man-Chung Wong

Chi-Seng Lam

Lei Wang

Wai-Hei Choi

Rui Paulo Da Silva Martins

Seng-Pan U

Sai-Weng Sin

U-Fat Chio

Ning-Yi Dai

Yajie Wu

Chi-Kong Wong

Yan-Zheng Yang

Ying-Duo Han

A hybrid-STATCOM for providing compensating reactive power required by a load, the hybrid-STATCOM comprising: a TCLC part for each electric power phase, each TCLC part comprising: a coupling inductor; a power filter capacitor; and a thyristor-controlled reactor connected in series with a power filter inductor; and an active inverter part comprising: a voltage source inverter for each electric power phase; and a DC-link capacitor connected in parallel with the voltage source inverters. The control strategy of the hybrid-STATCOM is separated into two parts: TCLC part control and Active inverter part control. The TCLC part control is based on the instantaneous pq theory and aims to compensate the loading reactive power with the controllable TCLC part impedance. The active inverter part control is based on the instantaneous active and reactive current i-imethod and aims to improve the overall performance of the hybrid-STATCOM under different voltage and current conditions.

Hybrid STATCOM with wide compensation range and low DC-link voltage

A thyristor controlled LC (TCLC) compensator for compensating dynamic reactive power in a power grid system, with an advantage of mitigating harmonic current injection from solid-state switches during switching on or off is provided. Exemplarily, the TCLC compensator is shunt-connected to the three-phase power grid and comprises an electronic controller, a coupling inductor (L), a first branch of circuit with a parallel inductor (L) and a solid-state switch, and a second branch of circuit with a parallel capacitor (C), wherein the coupling inductor (L) is connected in series with a parallel combination of the first and second branch of circuit. The electronic controller for the TCLC compensator is configured in accordance to the generalized instantaneous reactive power theory for improving the response speed instead of using traditional average reactive power concept.

Thyristor controlled LC compensator for compensating dynamic reactive power

A mixed signal controller for a power quality compensator includes an analog circuit, an analog-to-digital converter (ADC), and a digital circuit. The analog circuit amplifies an input signal from the power quality compensator by a gain factor and outputs an analog signal, which is converted to a digital signal by the ADC. The digital circuit receives the digital signal, calculates the reference compensating current of each phase and then generates a trigger signal via hysteresis PWM to the power quality compensator. The digital circuit includes an evaluation circuit that calculates a value of the system total harmonic distortion after the power quality compensator compensates power and adjusts the gain factor when the value of the system total harmonic distortion reaches a predetermined threshold.

Mixed signal controller

An adaptive dc-link voltage controlled LC coupling hybrid active power filter (LC-HAPF) for reactive power compensation includes: two dc capacitors to provide dc-link voltage; a three-phase voltage source inverter to convert dc-link voltage into compensating voltages; three coupling LC circuits to convert compensating voltages into currents; and an adaptive dc voltage controller with reactive power compensation control algorithm. The control algorithm includes: first, calculating required minimum dc-link voltage in each phase with respect to loading reactive power; three-phase required minimum dc-link voltage will be maximum one among their minimum values; compare it with predetermined voltage levels to determine final reference dc-link voltage. A dc-link voltage feedback P/PI controller outputs dc voltage reference compensating currents. An instantaneous power compensation controller outputs reactive reference compensating currents. The final reference compensating currents will be sum of them. A PWM circuit provides LC-HAPF adaptive dc-link voltage control and dynamic reactive power compensation.

Adaptive DC-link voltage controlled LC coupling hybrid active power filters for reactive power compensation

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Macau, Macao

Man-Chung Wong