Abstract: A power source system includes a first battery string, a second battery string, and a third battery string. Each of the battery strings includes a plurality of batteries capable of outputting direct-current power. The battery strings are Y-connected so as to output three-phase alternating-current power to three-phase output terminals (alternating-current output terminals) as well as connected to a neutral line. On the neutral line, a neutral line capacitor for blocking a direct current, a neutral line switch disposed in series to the neutral line capacitor, and an electric resistance element disposed in parallel to the neutral line switch are provided.

Abstract: The battery string is configured so that a plurality of battery circuit modules can be connected in series. The drive circuit SU5 from the drive circuit SU0 of the battery circuit module transmits a gate signal for ON/OFF of the switch to the downstream drive circuit SU while delaying the gate signal by a predetermined delay time Td. When a particular battery circuit module (drive circuit SU4 in FIG. 4) is passed through, the delay time is switched from the delay time Td to the delay time Tds. The delay time Tds is longer than the delay time Td. As a result, the period of the gate signal, which is the “delay time×the number of battery circuit modules to be operated”, can be suppressed from becoming short (the increase in frequency can be suppressed), and an increase in loss can be suppressed.

Abstract: The alternating current sweep unit outputs alternating current power from three battery strings that are Y-connected. The offset voltage command Vst_offset is calculated by adding the offset component V*abc_off of the string voltage obtained from the string voltage command V*abc, the amplitude Vamp of the command voltage calculated using dq shaft voltage command values v*d and v*q, and the margin voltage Vmrg. By determining the on-time ton of the gate signal by using the string voltage command V*abc and the offset voltage command Vst_offset and performing duty control on the gate signal, it is possible to set an offset voltage corresponding to the command voltage, and thus it is possible to suppress an increase in battery loss.

Abstract: To provide a porous plate for medical use which can suppress bending along a row direction and, even if a local crack occurs, can inhibit the crack from growing and leading to a fracture. One aspect of the present invention is a porous plate for medical use which is a thin-plate substrate provided with a pore perforation section having a plurality of pores perforated therein and a frame section surrounding the pore perforation section. In this porous plate, the pore perforation section has crosspieces which extend lengthwise and crosswise in continuity with the frame section and partition the pore perforation section into a plurality of parts, and a plurality of pore perforation cells each surrounded by the crosspieces. The pores perforated in the pore perforation cells have a pore diameter calculated as an equivalent circular pore diameter of 1 to 50 ?m, and the center-to-center distance between the adjacent pores is 2 to 200 ?m.

Abstract: To provide a porous plate for medical use which can suppress bending along a row direction and, even if a local crack occurs, can inhibit the crack from growing and leading to a fracture. One aspect of the present invention is a porous plate for medical use which is a thin-plate substrate provided with a pore perforation section having a plurality of pores perforated therein and a frame section surrounding the pore perforation section. In this porous plate, the pore perforation section has crosspieces which extend lengthwise and crosswise in continuity with the frame section and partition the pore perforation section into a plurality of parts, and a plurality of pore perforation cells each surrounded by the crosspieces. The pores perforated in the pore perforation cells have a pore diameter calculated as an equivalent circular pore diameter of 1 to 50 ?m, and the center-to-center distance between the adjacent pores is 2 to 200 ?m.