Abstract: A voltage compensation system and an uninterruptible power supply are provided. The voltage conversion device selectively receives the first AC input source or the second AC input source through the first switching device, and converts the first AC input source or the second AC input source into a DC voltage. The energy buffering device is connected with the DC busbar. The energy buffering device includes a bidirectional voltage conversion device and an energy tank. One terminal of the bidirectional voltage conversion device is connected with the DC busbar. The energy tank is connected with the other terminal of the bidirectional voltage conversion device. During a dead time of the first switching device switching between the first AC input source and the second AC input source, the controller controls the bidirectional voltage conversion device, so that the DC voltage is compensated by the energy tank.

Abstract: A power converter is coupled between a power source and multiple loads, and the power converter includes a first switch module. The switch module includes an inductor, a first switch, a second switch, a third switch, and a fourth switch. The first switch, the second switch, the third switch, and the fourth switch are configured to be turned on or turned off so that the inductor is stored energy or released energy to converter the power source into multiple voltages to the multiple loads.

Abstract: A voltage conversion circuit coupled to an alternating current (AC) input source and comprising an electronic circuit and a filter circuit is provided. The electronic circuit is coupled between positive and negative buses. The filter circuit reduces ripples of the AC input source and comprises a first capacitor, a second capacitor, a filter inductor and a first inductor. The first capacitor is coupled to the positive bus. The second capacitor is coupled to the first capacitor to form a common node, and coupled to the negative bus. Two terminals of the filter inductor are respectively coupled to the AC input source and the common node. A terminal of the first inductor is coupled to the common node. When the AC input source flows into the filter circuit from the common node, ripples of the AC input source are absorbed by at least one of the first and second capacitors.

Abstract: A power switching system includes a first power supply and a second power supply with three-phase AC power. The power switching system further includes a first power switch assembly, a second power switch assembly, and a three-phase transformer. The three-phase transformer includes a first winding, a second winding, and a third winding. The first winding, the second winding, and the third winding are connected in a delta structure to form three common nodes. A first common node is connected to a first switch and a fourth switch, a second common node is connected to a second switch and a fifth switch, and the third common node is connected to a third switch and a sixth switch.

Abstract: A cascaded converter includes four capacitors, four switches, a fifth switch and a first inductor, a sixth switch and a second inductor, and a seventh switch. The four capacitors include a first, a second, a third, and a fourth capacitor connected in series. The four switches include a first, a second, a third, and a fourth switch. The fifth switch and the first inductor are jointly connected at a sixth node, and the fifth switch is further connected to a first node and the first inductor is further connected to a fourth node. The sixth switch and the second inductor are jointly connected at a seventh node, and the sixth switch is further connected to a third node and the second inductor is further connected to a fifth node. The seventh switch is connected between the sixth node and the seventh node.

Abstract: A dual power switching system selects a first power source or a second power source to supply power to a load coupled to an inductive device. The dual power switching system includes a first thyristor, a second thyristor, a third thyristor, a fourth thyristor, and a controller. The controller calculates a total magnetic flux according to a current magnetic flux of the inductive device and an expected magnetic flux of the second power source. When the power-supplying source is switched, the controller turns off the first thyristor and the second thyristor, and determines whether a commutable time is reached according to a power parameter of the first static transfer switch and the second static transfer switch. When the commutable time is reached, the controller correspondingly turns on at least one of the third thyristor and the fourth thyristor according to the total magnetic flux being less than a threshold.

Abstract: A circulating current suppression method of a power system having a plurality of power modules is provided. Each power module includes a high-voltage bus, a low-voltage bus and a balance circuit having a neutral voltage. The circulating current suppression method includes: in each balance circuit, disposing a first capacitor electrically coupled between the high-voltage bus and the neutral voltage, and disposing a second capacitor electrically coupled between the neutral voltage and the low-voltage bus; acquiring a current effective value of an input of each power module; if detecting that the current effective value of at least one power module doesn't remain at a current reference value, determining that a circulating current occurs in the at least one power module; and operating the balance circuit of the at least one power module to charge the first capacitor or the second capacitor to regulate the neutral voltage for suppressing the circulating current.

Abstract: A power converter and a power conversion method are provided and capable of bus capacitor voltage balance based on inherent inductor components of the power converter. Compared with the conventional approach that adds a balance circuit, the power converter and the power conversion method can reduce a size of overall circuit and improve a power density. In addition, two relays of the power converter are configured to switch switching states such that two inductors store or release energy, thereby transmitting electrical energy between two bus capacitors and two load capacitors. The power converter and the power conversion method are able to realize energy balance and hybrid power supply and satisfy various load requirements.

Abstract: A dual power switching system selects a first power source or a second power source to supply power to a load coupled to an inductive device. The dual power switching system includes a first thyristor, a second thyristor, a third thyristor, a fourth thyristor, and a controller. The controller calculates a total magnetic flux according to a current magnetic flux of the inductive device and an expected magnetic flux of the second power source. When the power-supplying source is switched, the controller turns off the first thyristor and the second thyristor, and determines whether a commutable time is reached according to a power parameter of the first static transfer switch and the second static transfer switch. When the commutable time is reached, the controller correspondingly turns on at least one of the third thyristor and the fourth thyristor according to the total magnetic flux being less than a threshold.

Abstract: A power converter is provided. The power converter includes first to fourth switches electrically connected in series, a flying capacitor and a controller. Positive and negative terminals of the flying capacitor are electrically connected to the second and third switches respectively. The controller operates the first and fourth switches to perform a first complementary switching with a first dead time, and operates the second and third switches to perform a second complementary switching with a second dead time. The controller determines to regulate the first or second dead time by detecting a capacitor voltage of the flying capacitor, such that the capacitor voltage of the flying capacitor is maintained within a balance voltage range.

Abstract: A power converter and a power conversion method are provided and capable of bus capacitor voltage balance based on inherent inductor components of the power converter. Compared with the conventional approach that adds a balance circuit, the power converter and the power conversion method can reduce a size of overall circuit and improve a power density. In addition, two relays of the power converter are configured to switch switching states such that two inductors store or release energy, thereby transmitting electrical energy between two bus capacitors and two load capacitors. The power converter and the power conversion method are able to realize energy balance and hybrid power supply and satisfy various load requirements.

Abstract: A power converter is coupled between a power source and multiple loads, and the power converter includes a first switch module. The switch module includes an inductor, a first switch, a second switch, a third switch, and a fourth switch. The first switch, the second switch, the third switch, and the fourth switch are configured to be turned on or turned off so that the inductor is stored energy or released energy to converter the power source into multiple voltages to the multiple loads.

Abstract: A circulating current suppression method of a power system having a plurality of power modules is provided. Each power module includes a high-voltage bus, a low-voltage bus and a balance circuit having a neutral voltage. The circulating current suppression method includes: in each balance circuit, disposing a first capacitor electrically coupled between the high-voltage bus and the neutral voltage, and disposing a second capacitor electrically coupled between the neutral voltage and the low-voltage bus; acquiring a current effective value of an input of each power module; if detecting that the current effective value of at least one power module doesn't remain at a current reference value, determining that a circulating current occurs in the at least one power module; and operating the balance circuit of the at least one power module to charge the first capacitor or the second capacitor to regulate the neutral voltage for suppressing the circulating current.

Abstract: A power converter is provided. The power converter includes first to fourth switches electrically connected in series, a flying capacitor and a controller. Positive and negative terminals of the flying capacitor are electrically connected to the second and third switches respectively. The controller operates the first and fourth switches to perform a first complementary switching with a first dead time, and operates the second and third switches to perform a second complementary switching with a second dead time. The controller determines to regulate the first or second dead time by detecting a capacitor voltage of the flying capacitor, such that the capacitor voltage of the flying capacitor is maintained within a balance voltage range.

Abstract: A soft-switching power converter includes a main switch, an energy-releasing switch, and an inductive coupled unit. The main switch is a controllable switch. The energy-releasing switch is coupled to the main switch. The inductive coupled unit is coupled to the main switch and the energy-releasing switch. The inductive coupled unit includes a first inductance, a second inductance coupled to the first inductance, and an auxiliary switch unit. The auxiliary switch unit is coupled to the second inductance to form a closed loop. The main switch and the energy-releasing switch are alternately turned on and turned off. The auxiliary switch unit is controlled to start turning on before the main switch is turned on so as to provide at least one current path.

Abstract: A soft-switching power converter includes a main switch, an energy-releasing switch, and an inductive coupled unit. The main switch is a controllable switch. The energy-releasing switch is coupled to the main switch. The inductive coupled unit is coupled to the main switch and the energy-releasing switch. The inductive coupled unit includes a first inductance, a second inductance coupled to the first inductance, and an auxiliary switch unit. The auxiliary switch unit is coupled to the second inductance to form a closed loop. The main switch and the energy-releasing switch are alternately turned on and turned off. The auxiliary switch unit is controlled to start turning on before the main switch is turned on so as to provide at least one current path.

Abstract: A soft-switching power converter includes a main switch, an energy-releasing switch, and an inductive coupled unit. The main switch is a controllable switch. The energy-releasing switch is coupled to the main switch. The inductive coupled unit is coupled to the main switch and the energy-releasing switch. The inductive coupled unit includes a first inductance, a second inductance coupled to the first inductance, and an auxiliary switch unit. The auxiliary switch unit is coupled to the second inductance to form a closed loop. The main switch and the energy-releasing switch are alternately turned on and turned off. The auxiliary switch unit is controlled to start turning on before the main switch is turned on so as to provide at least one current path.

Abstract: An uninterruptible power apparatus is coupled between a power grid and a load. The uninterruptible power apparatus includes a bypass path, a power conversion module, and a control module. The bypass path is coupled to the power grid through a grid terminal, and coupled to the load through a load terminal. The control module turns off a first thyristor and a second thyristor by injecting a second voltage into the load terminal during a forced commutation period. The control module calculates a magnetic flux offset amount based on an error amount between the second voltage and a voltage command, and provides a compensation command in response to the magnetic flux offset amount. The control module controls the DC/AC conversion circuit to provide a third voltage to the load terminal based on the compensation command and the voltage command.

Abstract: An isolated conversion apparatus with magnetic bias balance control includes an isolated converter, a controller, and a magnetic bias balance circuit. The isolated converter includes a transformer, and a primary side of the transformer includes a primary-side winding and at least one switch bridge arm. The controller is coupled to the at least one switch bridge arm, and provides a pulse width modulation (PWM) signal group to control the at least one switch bridge arm. The magnetic bias balance circuit is coupled to two ends of the primary-side winding and the controller, and provides a compensation voltage to the controller according to an average voltage of a winding voltage across the two ends of the primary-side winding. The controller adjusts a duty cycle of the PWM signal group according to the compensation voltage to correct the magnetic bias.

Abstract: A ground fault detection apparatus is used to detect a ground fault of a three-phase UPS apparatus. The UPS apparatus includes a first filter circuit, an AC/DC conversion circuit, a DC bus, a DC/AC conversion circuit, and a second filter circuit coupled in sequence. The ground fault detection apparatus includes a detection circuit having a first detection end and a second detection end. The first detection end is coupled to the first filter circuit and the second filter circuit, and the second detection end is coupled to an equipment grounding point. The equipment grounding point is coupled to a neutral point of a three-phase power source, and the three-phase power source is coupled to the first filter circuit. The detection circuit indicates whether the UPS apparatus has a ground fault and a location where the ground fault occurs according to a detection voltage between the first detection end and the second detection end.