Abstract: A carriers synchronizing method of a hybrid frequency parallel inverter is proposed. A low-frequency ripple simulating step is performed to drive a high-frequency controlling unit to simulate a low-frequency ripple. An equidistant grid sampling step is performed to drive the high-frequency controlling unit to sample a sample ripple to generate a sample group and sample the low-frequency ripple to generate a plurality of low-frequency reference groups. An actual shifting angle searching step is performed to drive the high-frequency controlling unit to compare the sample group with the low-frequency reference groups to search an actual shifting angle from the reference shifting angles. A high-frequency carrier adjusting step is performed to drive a proportional integral controller to calculate the actual shifting angle to generate a sync reference, and then a period counter adjusts a starting point of the high-frequency carrier according to the sync reference.

Abstract: A carriers synchronizing method of a hybrid frequency parallel inverter is proposed. A low-frequency ripple simulating step is performed to drive a high-frequency controlling unit to simulate a low-frequency ripple. An equidistant grid sampling step is performed to drive the high-frequency controlling unit to sample a sample ripple to generate a sample group and sample the low-frequency ripple to generate a plurality of low-frequency reference groups. An actual shifting angle searching step is performed to drive the high-frequency controlling unit to compare the sample group with the low-frequency reference groups to search an actual shifting angle from the reference shifting angles. A high-frequency carrier adjusting step is performed to drive a proportional integral controller to calculate the actual shifting angle to generate a sync reference, and then a period counter adjusts a starting point of the high-frequency carrier according to the sync reference.

Abstract: A controlling method is for a single-phase bidirectional inverter. The single-phase bidirectional inverter includes a switch and an inductor. The controlling method for the single-phase bidirectional inverter includes an extracting step, a calculating step, and an integrating step. In the extracting step, a current command is inputted to the switch and obtaining a current through the inductor. The current is piecewisely linearized to extract a magnetizing inductance and a demagnetizing inductance of the inductor. In the calculating step, a duty ratio of the switch is used to calculate a variation of the current of the magnetizing inductance and a variation of the current of the demagnetizing inductance. In the integrating step, the variation of the current of the magnetizing inductance and the variation of the current of the demagnetizing inductance are integrated to obtain another duty ratio of the switch in the next cycle.

Abstract: A controlling method is for a single-phase bidirectional inverter. The single-phase bidirectional inverter includes a switch and an inductor. The controlling method for the single-phase bidirectional inverter includes an extracting step, a calculating step, and an integrating step. In the extracting step, a current command is inputted to the switch and obtaining a current through the inductor. The current is piecewisely linearized to extract a magnetizing inductance and a demagnetizing inductance of the inductor. In the calculating step, a duty ratio of the switch is used to calculate a variation of the current of the magnetizing inductance and a variation of the current of the demagnetizing inductance. In the integrating step, the variation of the current of the magnetizing inductance and the variation of the current of the demagnetizing inductance are integrated to obtain another duty ratio of the switch in the next cycle.

Abstract: A power converting device with a high frequency inverter module compensating a low frequency inverter module is for transmitting a direct current voltage to an alternating current load module. The low frequency inverter module is controlled by a low frequency duty ratio. The high frequency inverter module is connected to the low frequency inverter module in parallel and controlled by a high frequency duty ratio. The low frequency inverter module is controlled according to the low frequency duty ratio to generate a first current. The high frequency duty ratio is adjusted according to a low-frequency ripple current. The high frequency inverter module is controlled according to the high frequency duty ratio to generate a second current, and the second current is for compensating ripples of the first current.

Abstract: A three phase inverting device includes a three phase inverter module and a three phase filter module. The three phase inverter module includes a plurality of switches, each two switches are connected for forming a bridge arm, an input end of each of the bridge arm are coupled for forming a DC end, the DC end is connected to a DC load. The three phase filter module is connected to the three phase inverter module, wherein the three phase filter module includes a plurality of inductances and a plurality of capacitances, the inductances are connected at one side of the capacitances, a portion of the capacitances are connected to a output end of each of the bridge arm of the three phase inverter module, a portion of the inductances are connected to an AC end.

Abstract: A multi-function power converting apparatus including an inverter circuit and a controller is provided. The inverter circuit drives a load. The controller generates a control signal according to a sampled DC voltage, a sampled AC voltage, a load current, and an output current. The controller causes the inverter circuit to enter an uninterruptible power supply mode or a grid-connected power supply mode through the control signal. Specifically, when the inverter circuit enters the grid-connected power supply mode, the multi-function power converting apparatus operates in one of a mixed real-virtual power output mode, a rectification charging mode, an active filtering mode, and an active power balancing mode.

Abstract: A power converting method for high frequency inverter and low frequency inverter connecting in parallel, which is for converting a direct current power into an alternating current power, includes the following steps. A low frequency inverting module which electrically connected to the direct current power is provided. A high frequency inverting module which is electrically connected to the low frequency inverting module in parallel is provided. A high frequency switching duty ratio of the high frequency inverting module is adjusted to output a second current according to a first current produced by the low frequency inverting module. The second current is for compensating ripples of the first current.

Abstract: A power converting method for high frequency inverter and low frequency inverter connecting in parallel, which is for converting a direct current power into an alternating current power, includes the following steps. A low frequency inverting module which electrically connected to the direct current power is provided. A high frequency inverting module which is electrically connected to the low frequency inverting module in parallel is provided. A high frequency switching duty ratio of the high frequency inverting module is adjusted to output a second current according to a first current produced by the low frequency inverting module. The second current is for compensating ripples of the first current.

Abstract: A three-phase inverting apparatus and a control method and a paralleled power conversion system thereof are provided. The control method is suitable for controlling a three-phase inverter having a plurality of switch sets, a first inductor, a second inductor, and a third inductor. The control method includes following steps: obtaining a DC bus voltage, a plurality of phase voltages, and a plurality of phase currents; obtaining inductances of the first, the second, and the third inductors; calculating a plurality of switch duty ratios by a division-summation control means according to the DC bus voltage, the phase voltages, current variations of the phase currents, the inductances, and a switching cycle based on a sinusoidal pulse width modulation (SPWM); and generating corresponding control signals based on the switch duty ratios so as to control a switching of the switch sets.

Abstract: A three-phase inverting apparatus and a control method and a paralleled power conversion system thereof are provided. The control method is suitable for controlling a three-phase inverter having a plurality of switch sets, a first inductor, a second inductor, and a third inductor. The control method includes following steps: obtaining a DC bus voltage, a plurality of phase voltages, and a plurality of phase currents; obtaining inductances of the first, the second, and the third inductors; calculating a plurality of switch duty ratios by a division-summation control means according to the DC bus voltage, the phase voltages, current variations of the phase currents, the inductances, and a switching cycle based on a sinusoidal pulse width modulation (SPWM); and generating corresponding control signals based on the switch duty ratios so as to control a switching of the switch sets.

Abstract: The present disclosure provides a single-phase three-wire power control system integrating the electricity of a DC power supply device to an AC power source. The single-phase three-wire power control system comprises a single-phase three-wire inverter, a driving unit, a sampling unit and a processing unit. The single-phase three-wire inverter coupled between the DC power supply device and the AC power source converts a DC voltage of the DC power supply device to an output voltage. The driving unit is coupled to the single-phase three-wire inverter. The sampling unit samples the inductor current of an inductor of the single-phase three-wire inverter. The processing unit which is coupled to the driving unit and the sampling unit controls the single-phase three-wire inverter through the driving unit. The processing unit obtains the duty ratio according to the inductance of the inductor, the total variation of the inductor current, the DC voltage and the output voltage.

Abstract: Current of a three-phase multilevel modular converter (MMC) is controlled. The control is a division-summation (D-?) method yet uses integration to replace the two steps of division and summation. Common D-? characteristic equations are used for all areas. Inductance changes are considered in the characteristic equations. Current source is used to control converter. Therefore, the current of the converter can be traced to sinusoidal reference current even when the inductance changes become big. The modulation method and the capacitor-voltage balancing method are submodule unified pulse width modulation (SUPWM) and sorted voltage-balancing method, respectively. The current control directly obtains a law of the current change on each conducting module of an arm. It does not need complex sector judgments and table look-ups. Thus, the amount of computation and memory for a processor can be relatively reduced.

Abstract: A method is provided for current compensation. The method is based on division-sigma (D-?) control for a DC/DC converter. Inductance changes are allowed with D-? digital control achieved. Loop gain can be quickly adjusted. The disadvantage of average current-mode control (ACMC) is solved, where the disadvantage is a reduction of the response speed caused by the filter within the current loop. The present invention uses midpoint current sampling to ensure taking an average inductor current value in each switching cycle. By doing so, a lack of fidelity of peak current-mode control (PCMC) is solved, where the lack of fidelity is due to the amount of error value between the peak value and the average value. Besides, the present invention uses a table of the inductance following current changes to achieve compensation of duty cycle ratio, where the table is built in a single chip.

Abstract: A method is provided for current compensation. The method is based on division-sigma (D-?) control for a DC/DC converter. Inductance changes are allowed with D-? digital control achieved. Loop gain can be quickly adjusted. The disadvantage of average current-mode control (ACMC) is solved, where the disadvantage is a reduction of the response speed caused by the filter within the current loop. The present invention uses midpoint current sampling to ensure taking an average inductor current value in each switching cycle. By doing so, a lack of fidelity of peak current-mode control (PCMC) is solved, where the lack of fidelity is due to the amount of error value between the peak value and the average value. Besides, the present invention uses a table of the inductance following current changes to achieve compensation of duty cycle ratio, where the table is built in a single chip.

Abstract: The present invention provides a load impedance estimation and repetitive control method capable of allowing inductance variation for an inverter, wherein the method is applied for predicting corresponding next-period switching duty cycles for four switching member sets of the inverter by way of sampling three phase voltages and calculating next-period voltage compensations based on the previous line-period voltage compensations. Moreover, during the calculation and prediction, the method also involves the inductance variations of the output inductors of the inverter into the load impedance estimation matrix equation. Therefore, the three phases four wires inverter with the presented load impedance estimation and repetitive control method can provide a steady output voltage to the loads even if the originally-connected loads are replaced with other different loads.

Abstract: An LCL capacitor current compensation and control method based on division and summation technique, comprising following steps: calculating new reference current i*lr=power grid reference current (Igr)+estimated capacitor current (); calculating duty cycle ratio d of respective switches in inverter to obtain inductor current (il), through using corresponding division-and-summation digital control characteristic equation (A), (B), (C), or (D), as based on inverter code of various inverter types; calculating power grid current (ig)=inductor current (il)?capacitor current (ic); calculating voltage across inductor at power grid side (vc?vp)=impedance (Zg) of said inductor at power grid side x power grid current (ig); utilizing equation (4) to calculate voltage across capacitor (vc); estimating capacitor current ()=voltage across said capacitor (vc)/filtering capacitor impedance (Zc); and utilizing equation (3) to estimate capacitor current ().

Abstract: A three-phase current converter and a three-phase D-? control method with varied inductances are provided. In this method, two current variations of a first phase current, a second phase current and a third phase current flowing through a first inductor, a second inductor and a third inductor of the three-phase current converter respectively and two phase voltages of a first phase voltage, a second phase voltage and a third phase voltage are obtained. A first calculation is executed according to inductances of the inductors, the current variations and a switching period of a vector space modulation to obtain a calculation result. A second calculation is executed according to the phase voltages and the calculation result to obtain a duty ratio of the switching period of switch sets of the three-phase current converter. The inductances vary with the phase currents respectively.

Abstract: The present invention provides a load impedance estimation and repetitive control method capable of allowing inductance variation for an inverter, wherein the method is applied for predicting corresponding next-period switching duty cycles for four switching member sets of the inverter by way of sampling three phase voltages and calculating next-period voltage compensations based on the previous line-period voltage compensations. Moreover, during the calculation and prediction, the method also involves the inductance variations of the output inductors of the inverter into the load impedance estimation matrix equation. Therefore, the three phases four wires inverter with the presented load impedance estimation and repetitive control method can provide a steady output voltage to the loads even if the originally-connected loads are replaced with other different loads.

Abstract: The present disclosure provides a single-phase three-wire power control system integrating the electricity of a DC power supply device to an AC power source. The single-phase three-wire power control system comprises a single-phase three-wire inverter, a driving unit, a sampling unit and a processing unit. The single-phase three-wire inverter coupled between the DC power supply device and the AC power source converts a DC voltage of the DC power supply device to an output voltage. The driving unit is coupled to the single-phase three-wire inverter. The sampling unit samples the inductor current of an inductor of the single-phase three-wire inverter. The processing unit which is coupled to the driving unit and the sampling unit controls the single-phase three-wire inverter through the driving unit. The processing unit obtains the duty ratio according to the inductance of the inductor, the total variation of the inductor current, the DC voltage and the output voltage.