Uis Abler Electronics Co., Ltd.

Uis Abler Electronics., Ltd.

Hurng-Liang Chou

Chin-Chang Wu

Yao-Jen Chang

Wen-Pin Hsu

Ya-Tsung Feng

Ming-Hong Chiueh

Nan-Ying Shen

A hybrid reactive power compensation device comprises a passive type reactive power compensator and an active type reactive power compensator serially connected thereto. The passive type reactive power compensator is an AC power capacitor adapted to provide the reactive power that reduces capacity of the active type reactive power compensator. The active type reactive power compensator comprises a power converter, a DC capacitor, a high-frequency ripple filter and a controller. The hybrid reactive power compensation device can supply a linearly adjustable reactive power within a predetermined range, and is adapted to supply a current with a nearly sinusoidal waveform. Therefore, it can avoid the destruction of AC power capacitor caused by the power resonance.

Hybrid reactive power compensation device

A control method for the parallel-connected power converters includes a control circuit comprising a voltage feedback circuit and a current feed-forward circuit. The voltage feedback circuit, consisting of a voltage regulated control circuit and a waveform control circuit, is used to control the power converter's output voltage with constant amplitude and low total harmonic distortion. By adjusting the gain of waveform control circuit, it can regulate the current distribution among the parallel-connected power converters. The current feed-forward circuit separates the power converter's output current into the fundamental component and the harmonic component, and amplifies them by different gain. The amplified fundamental component acts as a fundamental resistor to suppress the circulating current among the parallel-connected power converters, and the amplified harmonic component acts as a harmonic damper for preventing from high frequency oscillation generated by the L-C filter.

Control method for parallel-connected power converters

A hybrid reactive power compensation device comprises a passive type reactive power compensator and an active type reactive power compensator serially connected thereto. The passive type reactive power compensator is an AC power capacitor adapted to provide the reactive power that reduces capacity of the active type reactive power compensator. The active type reactive power compensator is consisted of a power converter, a DC capacitor, a high-frequency ripple filter and a controller. The hybrid reactive power compensation device can supply a linearly adjustable reactive power within a predetermined range, and is adapted to provide with a serial-connected virtual harmonic damping. Therefore, it can avoid the destruction of AC power capacitor caused by the power resonance.

A hybrid reactive power compensation device comprises a passive type reactive power compensator and an active type reactive power compensator serially connected thereto. The passive type reactive power compensator is an AC power capacitor adapted to provide the reactive power that reduces capacity of the active type reactive power compensator. The active type reactive power compensator is consisted of a power converter, a DC capacitor, a high-frequency ripple filter and a controller. The hybrid reactive power compensation device can supply a linearly adjustable reactive power within a predetermined range, and the supplied current is approximated to be a sinusoidal waveform. Therefore, it can avoid the destruction of AC power capacitor caused by the power resonance.

A DC/DC boost converter is consisted of an inductor, a power electronic switch, a control circuit, a first diode, a second diode and a capacitor. The power electronic switch is not operated if the input DC voltage is higher than the specified low reference DC voltage and it is regarded as the normal input DC voltage. If the input DC voltage is lower than the specified low reference DC voltage and this condition is regarded as the abnormal input DC voltage, the power electronic switch is controlled by pulse width modulation control and a dc voltage across the capacitor is created. Then, the output DC voltage is the summation of the input DC voltage and the capacitor voltage. Thus, the inventive DC/DC boost converter operates only when the input DC voltage is abnormal, thereby avoid additional power loss in the duration of normal input DC voltage.

DC/DC boost converter and control method therefor

An active harmonic suppression equipment is consisted of a dc capacitor, a power converter, a serially connected inductor/capacitor set, a C-R-C filter set and a control circuit. The dc capacitor operates as an energy storage device and supplies a dc voltage, and the power converter electrically connected thereto is used to convert the dc voltage into a compensating voltage. The inductor/capacitor set and the C-R-C filter set are commonly converting the compensating voltage into a compensating current injecting into a power feeder in order to suppress harmonic currents generated by nonlinear loads, thereby adjusting an utility current to be approximated as a sine-wave.

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Kaohsiung, Taiwan

Hurng-Liang Chou