A power conversion system converts an input alternating-current voltage having a first frequency into an output alternating-current voltage having a second frequency lower than the first frequency. The power conversion system includes a voltage converter, a PDM controller, and a feedback controller. The voltage converter converts the input alternating-current voltage into the output alternating-current voltage in accordance with control signals and outputs the output alternating-current voltage to a load. The PDM controller performs pulse density modulation of an output voltage command value of the output alternating-current voltage to generate the control signals and outputs the control signals to the voltage converter. The feedback controller generates the output voltage command value based on an output current value of the voltage converter and a state of the load and outputs the output voltage command value to the PDM controller.

The invention relates to a high-frequency resonant power conversion system for transferring power from an oscillator to a load or vice-versa, the system comprising components with at least one fluctuating parameter and is configured to control the value of a defined variable selected from: a certain current, a certain voltage, a phase difference between a certain voltage and a certain current, and a certain power; the system further comprising a virtual impedance creation loop which is configured to create a virtual component, said virtual component forming a basis for changing amplitude and a phase of the oscillator, thereby to compensate for a deviation from the controlled variable due to said fluctuations.

The invention relates to a high-frequency resonant power conversion system for transferring power from an oscillator to a load or vice-versa, the system comprising components with at least one fluctuating parameter and is configured to control the value of a defined variable selected from: a certain current, a certain voltage, a phase difference between a certain voltage and a certain current, and a certain power; the system further comprising a virtual impedance creation loop which is configured to create a virtual component, said virtual component forming a basis for changing amplitude and a phase of the oscillator, thereby to compensate for a deviation from the controlled variable due to said fluctuations.

A matrix converter control device includes a plurality of delay circuits which correspond to logic change timings of a plurality of input pulse width modulation (PWM) signals for controlling ON and OFF states of a plurality of switching elements included in a matrix converter. Specifically, the plurality of delay circuits are a first delay circuit, a second delay circuit, a third delay circuit, a fourth delay circuit, and a fifth delay circuit, Each of the plurality of delay circuits delays an input PWM signal by an amount of delay set for the delay circuit at a logic change timing corresponding to the delay circuit.

A matrix converter control device includes a plurality of delay circuits which correspond to logic change timings of a plurality of input pulse width modulation (PWM) signals for controlling ON and OFF states of a plurality of switching elements included in a matrix converter. Specifically, the plurality of delay circuits are a first delay circuit, a second delay circuit, a third delay circuit, a fourth delay circuit, and a fifth delay circuit, Each of the plurality of delay circuits delays an input PWM signal by an amount of delay set for the delay circuit at a logic change timing corresponding to the delay circuit.

A downhole tool and a method for operating the downhole tool are disclosed. A first power signal is supplied to the downhole tool from a power source at a first frequency. A bidirectional chopper at the downhole tool chops the first power signal to generate a second power signal having a second frequency greater than the first frequency. The second power signal is used to operate the downhole tool.

A power supply control device according to one or more embodiments may be provided, in which a power conversion device has a configuration in which a resonant circuit is provided on an output side of a matrix converter using switching circuits including snubber elements so as to perform AC-AC conversion of output from a multi-phase AC power supply. The power conversion device is controlled to make an amplitude of an output current, a phase of the output current and an instantaneous reactive power as close to a control target as possible. The amplitude and the phase of the output current and the instantaneous reactive power are derived based on: an input voltage and a phase of a multi-phase current input to the power conversion device; and characteristics of the resonant circuit.

A power supply control device according to one or more embodiments may be provided, in which a power conversion device has a configuration in which a resonant circuit is provided on an output side of a matrix converter using switching circuits including snubber elements so as to perform AC-AC conversion of output from a multi-phase AC power supply. The power conversion device is controlled to make an amplitude of an output current, a phase of the output current and an instantaneous reactive power as close to a control target as possible. The amplitude and the phase of the output current and the instantaneous reactive power are derived based on: an input voltage and a phase of a multi-phase current input to the power conversion device; and characteristics of the resonant circuit.

An electrical power distribution network is disclosed, the network can include: a plurality of electrical power control apparatuses, each of the electrical power control apparatuses including: one or more signal conversion components receiving electrical power in the form of a corresponding first signal having a corresponding first fundamental frequency and a corresponding first characteristic voltage, and generating a corresponding second signal having a corresponding second fundamental frequency and a corresponding second characteristic voltage; and a controller that controls operation of the signal conversion components to determine an output voltage and an output frequency of an output signal of the electrical power control apparatus; 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.

An electrical power distribution network is disclosed, the network can include: a plurality of electrical power control apparatuses, each of the electrical power control apparatuses including: one or more signal conversion components receiving electrical power in the form of a corresponding first signal having a corresponding first fundamental frequency and a corresponding first characteristic voltage, and generating a corresponding second signal having a corresponding second fundamental frequency and a corresponding second characteristic voltage; and a controller that controls operation of the signal conversion components to determine an output voltage and an output frequency of an output signal of the electrical power control apparatus; 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.