A power converter includes at least one arm having a plurality of converter cells cascaded to each other. Each of the converter cells includes a pair of input/output terminals, a plurality of switching elements, and a power storage element. The power storage element is electrically connected to the input/output terminals through the switching elements. A control device generates a control signal for controlling on and off of the switching elements of each converter cell. The control device generates the control signal by pulse width modulation control based on a modulation command signal including an AC component having a fundamental frequency and corresponding to a command value of an output voltage between the input/output terminals, in each converter cell, such that a harmonic component included in the output voltage and having a predetermined frequency that is an integer multiple of the fundamental frequency is suppressed.

A power converter includes at least one arm having a plurality of converter cells cascaded to each other. Each of the converter cells includes a pair of input/output terminals, a plurality of switching elements, and a power storage element. The power storage element is electrically connected to the input/output terminals through the switching elements. A control device generates a control signal for controlling on and off of the switching elements of each converter cell. The control device generates the control signal by pulse width modulation control based on a modulation command signal including an AC component having a fundamental frequency and corresponding to a command value of an output voltage between the input/output terminals, in each converter cell, such that a harmonic component included in the output voltage and having a predetermined frequency that is an integer multiple of the fundamental frequency is suppressed.

A method for actuating an electrical circuit arrangement including at least one switching element. The switching element is actuated by a driver circuit as a function of switching-signal information for switch-on and switch-off. The switching-signal information is continuously determined and a switch-on period and signal position information are specified respectively for at least one switching-signal time window with a fixed duration. The position of the switch-on signal within the switching-signal time window is specified by the signal position information for a switch-on signal that results from a switch-on period that is less than the duration of the switching-signal time window.

This motor control device includes a vector control unit. The vector control unit includes: a current control unit that calculates a before-compensation d-axis voltage command value and a before-compensation q-axis voltage command value; a first non-interference control unit that calculates a first d-axis non-interference compensation value on the basis of a q-axis current command value to compensate for the before-compensation d-axis voltage command value and calculates a first q-axis non-interference compensation value on the basis of a d-axis current command value to compensate for the before-compensation q-axis voltage command value; and a second non-interference control unit that cancels out an interference component of a d-axis current generated in a specific rotation range of a motor with a q-axis current and an interference component of the q-axis current generated in the specific rotation range with the d-axis current by using a variable integral gain varying depending on a motor rotation speed.

The present disclosure relates to the field of electric power system, and more particularly to a topology of a series-connected MMC with a small number of modules, where the topology is composed of a three-phase bridge circuit, half-bridge valve strings, a three-phase filter inductor, and a three-phase grid frequency transformer. The topology of a series-connected MMC with a small number of modules in the present disclosure needs only two half-bridge valve strings, thus greatly reducing the number of the submodules as compared with the conventional MMC structure. When achieving the same high DC voltage output, the present disclosure can improve the power density of the MMC, realize stable three-phase AC output voltage, and further achieve balance of capacitor voltages in the two half-bridge valve strings. Compared to the conventional MMC topology, the topology in the present disclosure can reduce the number of submodules by nearly 2/3, and has a greater AC-DC voltage transfer ratio, thus reducing the cost of the MMC converter, reducing the device size, and improving the power density.

A pulse width-modulated (PWM) driving method is provided for a PWM motor control system with zero-crossing compensation. The PWM driving method includes controlling each carrier generator of first, second and third PWM generators to generate a carrier offset between each of first, second and third carrier signals, at least when a current flowing in a respective phase of an alternating current (AC) motor of the PWM motor control system is between +/− 10 mA, such that a voltage between respective nodes and a reference point of respective half-bridges of the PWM motor control system are offset to obtain a variable common mode voltage each time respective PWM signals are in an off-state, at least when the respective current is crossing zero.

A pulse width-modulated (PWM) driving method is provided for a PWM motor control system with zero-crossing compensation. The PWM driving method includes controlling each carrier generator of first, second and third PWM generators to generate a carrier offset between each of first, second and third carrier signals, at least when a current flowing in a respective phase of an alternating current (AC) motor of the PWM motor control system is between +/− 10 mA, such that a voltage between respective nodes and a reference point of respective half-bridges of the PWM motor control system are offset to obtain a variable common mode voltage each time respective PWM signals are in an off-state, at least when the respective current is crossing zero.

In a power conversion system, a power converter includes a power conversion circuit connected to a direct current (DC) source via a DC distribution line and converts and supplies received DC power to a load, and a power conversion control unit. A power stabilizing device is disposed between the DC distribution line and the power converter and stabilizes a DC voltage applied from the DC power source. A control power source of the power stabilizing device performs current control of the current transformer to suppress DC magnetization caused by a DC current component of the primary current while compensating for a varying component of the DC voltage. The control power source acquires current information or voltage information calculated from control information used by the power conversion control unit for control operations related to energization of the load and uses it as control information for the power stabilizing device.

In a power conversion system, a power converter includes a power conversion circuit connected to a direct current (DC) source via a DC distribution line and converts and supplies received DC power to a load, and a power conversion control unit. A power stabilizing device is disposed between the DC distribution line and the power converter and stabilizes a DC voltage applied from the DC power source. A control power source of the power stabilizing device performs current control of the current transformer to suppress DC magnetization caused by a DC current component of the primary current while compensating for a varying component of the DC voltage. The control power source acquires current information or voltage information calculated from control information used by the power conversion control unit for control operations related to energization of the load and uses it as control information for the power stabilizing device.

An object of the present invention is to provide a motor control device that can suppress electromagnetic noises including a switching noise and to an electric vehicle system using the motor control device. A motor control device includes: a power converter that is controlled by a pulse width modulation signal; a motor that is driven by the power converter; and a controller that generates the pulse width modulation signal, based on a carrier signal. When switching between a first carrier frequency (fc1) of the carrier signal and a second carrier frequency (fc2) of the carrier signal, the controller varies proportions of the first carrier frequency and the second carrier frequency in accordance with a number of rotations of the motor, the second carrier frequency being higher than the first carrier frequency.