An AC-to-AC modular multilevel converter (MMC) is configured to be connected between a three-phase AC system and a single-phase AC system. The MMC includes a number of converter arms connected in a ring to allow a circulating current to be circulated in the ring through each of the converter arms. Each converter arm includes series-connected converter cells. Phase terminals are arranged in the ring between the converter arms such that each of the converter arms is separated from neighboring converter arms by at least one of the phase terminals. The phase terminals include respective terminals for each of a first phase, a second phase and a third phase of the three-phase AC system and respective terminals for each of a positive conductor and a negative conductor of the single-phase AC system.

An intelligent current control apparatus provides a current control for a power supply branch and a load. The intelligent current control apparatus includes at least one power conversion unit and a control unit. The control unit controls a total phase current, which is composed of a single-phase current and a household phase current in the same phase, to be less than or equal to a rated phase current of the power supply branch.

A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: calculate a deterioration level based on a secondary side current of the matrix converter circuitry, a carrier frequency, and a primary-secondary frequency difference between a primary side frequency and a secondary side frequency of the matrix converter circuitry; and output a deterioration notification in response to determining that the deterioration level exceeds a predetermined level.

A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: calculate a deterioration level based on a secondary side current of the matrix converter circuitry, a carrier frequency, and a primary-secondary frequency difference between a primary side frequency and a secondary side frequency of the matrix converter circuitry; and output a deterioration notification in response to determining that the deterioration level exceeds a predetermined level.

A multi-winding single-stage multi-input boost type high-frequency link's inverter with simultaneous/time-sharing power supplies, having the circuit structure formed by connecting a plurality of mutually isolated high-frequency inverter circuits having an input filter and an energy storage inductor, a common output cycloconverter and filter circuit by a multi-input single-output high-frequency transformer. Each input end of the multi-input single-output high-frequency transformer is connected in one-to-one correspondence to the output end of each high-frequency inverter circuit. The output end of the multi-input single-output high-frequency transformer is connected to the input end of the output cycloconverter and filter circuit. The inverter has the following characteristics: multiple input sources are connected to a common ground or a non-common ground. The multiple input sources supply power to load in a simultaneous/time-sharing manner. The output and input high-frequency isolation is performed. The output cycloconverter and filter circuit is shared.

Apparatus and methods for supplying DC power to control circuitry of a matrix converter is provided. In certain embodiments, a matrix converter includes an array of switches having AC inputs for receiving a multi-phase AC input voltage and AC outputs for providing a multi-phase AC output voltage to a load, such as an electric motor. The matrix converter further includes control circuitry for opening or closing individual switches of the array, and a clamp circuit connected between the AC inputs and AC outputs of the array and operable to dissipate energy of the load in response to an overvoltage condition, such as an overvoltage condition arising during shutdown. The clamp circuit includes a switched mode power supply operable to generate a DC supply voltage for the control circuitry.

An electrical power distribution network includes: a plurality of electrical power control apparatuses, each of which include one or more signal conversion components receiving electrical power in the form of a first signal and generating a corresponding second signal, a controller that controls operation of the signal conversion components, electrical power generation components acting as sources of electrical power to at least some of the electrical power control apparatuses, and electrical power consumption components acting as sinks of electrical power from at least some of the electrical power control apparatuses. The electrical power control apparatuses operate autonomously but are interconnected so that the electrical power control apparatuses collectively maintain the voltages and frequencies of electrical power signals flowing through the electrical power distribution network at target values to compensate for variations in the sinks and/or sources of electrical power.

An electrical power distribution network includes: a plurality of electrical power control apparatuses, each of which include one or more signal conversion components receiving electrical power in the form of a first signal and generating a corresponding second signal, a controller that controls operation of the signal conversion components, electrical power generation components acting as sources of electrical power to at least some of the electrical power control apparatuses, and electrical power consumption components acting as sinks of electrical power from at least some of the electrical power control apparatuses. The electrical power control apparatuses operate autonomously but are interconnected so that the electrical power control apparatuses collectively maintain the voltages and frequencies of electrical power signals flowing through the electrical power distribution network at target values to compensate for variations in the sinks and/or sources of electrical power.

An apparatus includes a first inverter circuit and a second inverter circuit. The first invertor circuit is configured to couple an alternator and a load device to deliver a driving signal from the alternator to the load device. The second invertor circuit is configured to couple the alternator to the load device to deliver a driving signal from the alternator to the load device and configured to couple a battery to the alternator to deliver a charging signal from the alternator the battery

A motor control method includes the following steps: receiving a frequency command and an excitation current setting value as a motor speed command; running a magnetic flux calculation program to generate a magnetic flux voltage command; generating a synchronous coordinate voltage command, and providing a three-phase current to a sensorless motor; calculating a synchronous coordinate feedback current based on the three-phase current, and calculating an effective current value of three-phase current; calculating a reactive power feedback value based on synchronous coordinate voltage command and the synchronous coordinate feedback current; running a steady state calculation program to calculate a reactive power command based on frequency command and the effective current value; calculating a reactive power error value between the reactive power command and the reactive power feedback value; and adding magnetic flux voltage command and reactive power error value to adjust synchronous coordinate voltage command and change three-phase current.