Abstract: An electric power converter is equipped with a master converter and a slave converter that are connected in parallel with each other, and to a load. The master converter operates having priority over the slave converter. The slave converter includes a voltage sensor for detecting an output voltage of the electric power converter and a control unit for controlling an output of the slave converter based on a target command value. The control unit selects a current command value Ic2 received from the master converter as a target command value when a variation ?V per predetermined time of a detected output voltage Vo2 is lower than a variation ?Vth1. The control unit selects a voltage command value Vc2a calculated so as to suppress the output voltage Vo2 from changing as the target command value when the variation ?V exceeds the variation ?Vth1.

Abstract: In a current detection circuit, a first circuit is connected between a first terminal and a second terminal, and a second circuit is connected between a third terminal and a fourth terminal. The second terminal and the fourth terminal are commonly connected. When a first current flows between the first and second terminals, voltage drop occurs in the first circuit. A current control circuit controls the first current to make an application voltage between the first and second terminals substantially same as an application voltage between the third and fourth terminals. When the first circuit has voltage drop same as the second circuit, the first current has the amount proportional to the second current. A detection circuit detects a current flowing between the first terminal and the third terminal by detecting the first current controlled by the current control circuit or the second current.

Abstract: An electric power converter is equipped with a master converter and a slave converter that are connected in parallel with each other, and to a load. The master converter operates having priority over the slave converter. The slave converter includes a voltage sensor for detecting an output voltage of the electric power converter and a control unit for controlling an output of the slave converter based on a target command value. The control unit selects a current command value Ic2 received from the master converter as a target command value when a variation ?V per predetermined time of a detected output voltage Vo2 is lower than a variation ?Vth1. The control unit selects a voltage command value Vc2a calculated so as to suppress the output voltage Vo2 from changing as the target command value when the variation ?V exceeds the variation ?Vth1.

Abstract: In a current detection circuit, a first circuit is connected between a first terminal and a second terminal, and a second circuit is connected between a third terminal and a fourth terminal. The second terminal and the fourth terminal are commonly connected. When a first current flows between the first and second terminals, voltage drop occurs in the first circuit. A current control circuit controls the first current to make an application voltage between the first and second terminals substantially same as an application voltage between the third and fourth terminals. When the first circuit has voltage drop same as the second circuit, the first current has the amount proportional to the second current. A detection circuit detects a current flowing between the first terminal and the third terminal by detecting the first current controlled by the current control circuit or the second current.

Abstract: A power converter including a main circuit and a sub-circuit. The main circuit serves as a step-up/down chopper circuit including a series-connected assembly of main switches, an inductor coupled to a joint of the main switches, and a capacitor connected in parallel to the series-connected assembly. The sub-circuit is designed to establish the soft-switching and includes a snubber capacitor, a first sub-switch coupled to the joint of the series-connected assembly and a negative terminal of the snubber capacitor, a second sub-switch coupled to the joint and a positive terminal of the snubber capacitor, a third sub-switch coupled to the positive terminal of the snubber capacitor and a high-potential terminal of the main circuit, and a fourth sub-switch coupled to the negative terminal of the snubber capacitor and a low-potential terminal of the main circuit.