In a method for operating a drive system, and drive system, having a rectifier and at least one inverter including an electric motor, the electric motor is connected at the AC-voltage-side connection of the inverter, the DC-voltage-side connection of the inverter is connected via inductance(s) in addition to the line inductance, to the DC-voltage-side connection of the rectifier, a capacitance is connected at the DC-voltage-side connection of the inverter and/or at the DC-voltage-side connection of the rectifier, a series circuit, including a resistor and a controllable semiconductor switch is connected at the DC-voltage-side connection of the inverter and/or at the DC-voltage-side connection of the rectifier, the braking chopper being operated using a single frequency during the particular time span in which the braking chopper is in operation, the frequency, e.g., being set apart from the resonant frequency of the resonant circuit including the inductance or the capacitances.

A power conversion system includes: power conversion circuitry including a plurality of submodules connected in series to each other; a host device to control each submodule included in the power conversion circuitry; a terminal device to display internal information about each submodule; and at least one repeating device to relay communication between the host device and each submodule and communication between the terminal device and each submodule. The repeating device receives, from one or more submodules communicating with the repeating device, internal information about the submodules, transmits, to the host device with a first cycle period, a first communication frame including aggregate information that is an aggregate of the received internal information, and transmits, to the terminal device with a second cycle period longer than the first cycle period, a second communication frame including internal information selected from the received internal information.

A voltage drop Vz.sub.s is calculated based on an output current detection value Iac and a virtual synchronous impedance Zs or a corrected virtual synchronous impedance Zs′, and a value obtained by subtracting the voltage drop Vz.sub.s from an internal induced voltage Ef is output as a grid voltage command value Vac*. Zs calculation unit 7 limits an output current phase θ so that the output current phase θ is within an effective range by a phase limiter 12a, and calculates the corrected virtual synchronous impedance Zs′ based on a limited output current phase θ, the internal induced voltage Ef, a grid voltage detection value Vac and a current limit value Ilim. Accordingly, in grid interconnection power conversion device that controls a virtual synchronous generator, it is possible to continue operation while suppressing an overcurrent and possess a synchronizing power generated by action or working of a virtual synchronous impedance.

A power factor correction circuit comprising: a global voltage input; and means for deriving a reference current from the global voltage; whereby the means for deriving the reference current comprises a digital leading phase admittance cancellation, DLPAC, transfer function and a filter, whereby the reference current is derived from a sum of an output of the DLPAC transfer function and an output of the filter, and further comprising means for compensating for delays in the DLPAC function.

Systems and methods for controlling a dual active bridge converter are disclosed herein. An output voltage of a dual active bridge converter is sensed. Based at least in part on the output voltage, a target intra-bridge phase shift amount between two bridges of the dual active bridge converter is computed. A plurality of switch control signals, which are provided to respective switches of the dual active bridge converter, are caused to switch according to a time-based switching sequence based on the target intra-bridge phase shift amount to compensate for variations in the output voltage.

An example method for controlling a DC/DC converter or a standalone DC microgrid comprises an artificial neural network (ANN) based control method integrated with droop control. The ANN is trained to implement optimal control based on approximate dynamic programming. In one example, Levenberg-Marquardt (LM) algorithm is used to train the ANN, where the Jacobian matrix needed by LM algorithm is calculated via a Forward Accumulation Through Time algorithm. The ANN performance is evaluated by using power converter average and switching models. Performance evaluation shows that a well-trained ANN controller has a strong ability to maintain voltage stability of a standalone DC microgrid and manage the power sharing among the parallel distributed generation units. Even in dynamic and power converter switching environments, the ANN controller shows an ability to trace rapidly changing reference commands and tolerate system disturbances, and operate the DC/DC converter or the microgrid in standalone conditions.

According to an aspect, a power supply system includes a plurality of power converters configured to deliver a system load current to a load, where the system load current is a combination of individual load currents provided by the plurality of power converters, and a system performance controller configured to detect a value of the system load current. The system performance controller is configured to determine, using power loss information, values for the individual load currents such that a composite efficiency achieves a threshold condition. The system performance controller is configured to generate control signals to operate the plurality of power converters at the determined values.

A control circuit for controlling switching operation of a switching stage of a converter includes a phase detector circuit that generates a pulse-width modulated (PWM) signal in response to a phase comparison of two clock signals. A first clock signal has a frequency determined as a function of a first feedback signal proportional to converter output voltage. A first transconductance amplifier generates a first current indicative of a difference between a reference voltage and the first feedback signal, and a second transconductance amplifier generates a second current indicative of a difference between the reference voltage and a second feedback signal proportional to a derivative of the converter output voltage. A delay line introduces a delay in the first clock signal that is dependent on the first and second currents as well as a compensation current dependent on a selected operational mode of the converter.

A power control unit is provided to control the efficiency of a charge pump converter having a first input terminal and a second input terminal, a primary attenuator and a secondary attenuator between a first input terminal and the second input terminal, a first output terminal, a second output terminal, a secondary attenuator controlling terminal and a primary attenuator controlling terminal to be plugged to the power control unit. The primary attenuator controlling terminal and the secondary attenuator controlling terminal are to attenuate or amplify a signal of the first input terminal and the second input terminal.

A control method for a bi-directional DC/DC converter. A source terminal transmits electric energy to a destination terminal sequentially through a first rectifier module and a second rectifier module of the converter. The method includes obtaining a first voltage value output by the first rectifier module in a current control cycle, obtaining a second voltage value output by the second rectifier module in the current control cycle, calculating a theoretical voltage control quantity of the bi-directional DC/DC converter in the current control cycle based on a preset reference voltage value and the second voltage value, and setting an actual output voltage of the bi-directional DC/DC converter in a next control cycle based on the theoretical voltage control quantity and the first voltage value.