A power conversion device includes a power conversion circuit and a power conversion control circuit. The power conversion control circuit is configured to calculate a positive-phase sequence current command signal based on a positive-phase sequence voltage of the three-phase AC output voltage and a positive-phase sequence current of the three-phase AC output current, calculate a negative-phase sequence current command signal based on the first axis negative-phase sequence current command value, the second axis negative-phase sequence current command value, the first axis negative-phase sequence current value, and the second axis negative-phase sequence current value, and generate the switching control signal based on the positive-phase sequence current command signal and the negative-phase sequence current command signal.

A power conversion device includes a plurality of conversion units electrically connected in parallel to each other and configured to perform voltage conversion of electric power supplied from a power supply and a control device configured to set a conversion unit that will operate within the plurality of conversion units, wherein, after the number of conversion units that are operating within the plurality of conversion units is increased, the control device makes an electric current flowing through an operation start conversion unit which is a conversion unit that has started to operate from a non-operating state larger than an electric current flowing through an operation maintenance conversion unit which is a conversion unit that continues to operate before and after the number of operating conversion units is increased.

A power conversion device includes a plurality of conversion units electrically connected in parallel to each other and configured to perform voltage conversion of electric power supplied from a power supply and a control device configured to set a conversion unit that will operate within the plurality of conversion units, wherein, after the number of conversion units that are operating within the plurality of conversion units is increased, the control device makes an electric current flowing through an operation start conversion unit which is a conversion unit that has started to operate from a non-operating state larger than an electric current flowing through an operation maintenance conversion unit which is a conversion unit that continues to operate before and after the number of operating conversion units is increased.

The present invention provides an electric power conversion device and an electric power generation system which are capable of suppressing ripples in a detected voltage and detection delay.

A method for operating switching elements of a multilevel energy converter using at least three electric potentials and to which a multiphase electrical machine is connected. Switching elements of the multilevel energy converter are operated in a predefined clock mode by corresponding switching signals. The switching signals for the switching elements are each assigned to one of the phases and are determined in accordance with each desired voltage signal, in order to apply a phase voltage to each phase of the multiphase electrical machine. The switching signals are determined additionally in accordance with a predefined overlaying voltage signal such that an overlaying voltage dependent on the overlaying voltage signal is overlaid onto each phase voltage.

A method for operating switching elements of a multilevel energy converter using at least three electric potentials and to which a multiphase electrical machine is connected. Switching elements of the multilevel energy converter are operated in a predefined clock mode by corresponding switching signals. The switching signals for the switching elements are each assigned to one of the phases and are determined in accordance with each desired voltage signal, in order to apply a phase voltage to each phase of the multiphase electrical machine. The switching signals are determined additionally in accordance with a predefined overlaying voltage signal such that an overlaying voltage dependent on the overlaying voltage signal is overlaid onto each phase voltage.

A power conversion device includes two lower arm switching elements connected in parallel to each other and a lower arm driver circuit that drives the two lower arm switching elements. The two lower arm switching elements respectively include gate terminals and detection terminals used to detect counter-electromotive forces. The power conversion device includes a common connection line that connects the two detection terminals to each other and connects the two detection terminals to an addition circuit of the lower arm driver circuit. A combined electromotive force is transmitted via the common connection line.

A power conversion device includes two lower arm switching elements connected in parallel to each other and a lower arm driver circuit that drives the two lower arm switching elements. The two lower arm switching elements respectively include gate terminals and detection terminals used to detect counter-electromotive forces. The power conversion device includes a common connection line that connects the two detection terminals to each other and connects the two detection terminals to an addition circuit of the lower arm driver circuit. A combined electromotive force is transmitted via the common connection line.

Provided are a power conversion device and a remote monitoring system capable of calculating the life of a power semiconductor device with high accuracy. In order to achieve the above purpose, a power conversion device, which controls the flow or interruption of a current with an inverter having a power semiconductor device and performs desired power conversion, comprises: a motor control unit which calculates a gate signal on the basis of a current value, a speed command, and a carrier frequency detected by a current sensor and controls the inverter; a temperature history calculator which estimates the loss of the power semiconductor device and calculates a temperature history; a temperature history storage device which stores the calculation result of the temperature history; and a damage calculator which calculates damage to the power semiconductor device from the temperature history read from the temperature history storage device.

Provided are a power conversion device and a remote monitoring system capable of calculating the life of a power semiconductor device with high accuracy. In order to achieve the above purpose, a power conversion device, which controls the flow or interruption of a current with an inverter having a power semiconductor device and performs desired power conversion, comprises: a motor control unit which calculates a gate signal on the basis of a current value, a speed command, and a carrier frequency detected by a current sensor and controls the inverter; a temperature history calculator which estimates the loss of the power semiconductor device and calculates a temperature history; a temperature history storage device which stores the calculation result of the temperature history; and a damage calculator which calculates damage to the power semiconductor device from the temperature history read from the temperature history storage device.