Mitsubishi Heavy Industries Limited

Pioneer Corporation

Nec Corporation

Mitsubishi Electric Corporation

Hiroshi Shirasawa

Hironobu Shinohara

Shinji Kiuchi

Yasutake Akizuki

Toshiki Fukui

Hiroshi Fujimoto

Yuichi Tanaka

Takatoshi Shoji

Mitsuhiro Ishizuka

Teruo Okamura

Tadashi Nakamura

Eiichi Urushibata

Toshiaki Matsumura

Sohei Okamoto

Kazuyoshi Ide

A nuclear power plant control system including: a detection unit for detecting a specific event occurring in the nuclear power plant; an on-site equipment handling the event; and a majority decision judging device and an on-site equipment control device which constitute a plurality of control devices respectively operating independently. Each of the control devices includes a plurality of arithmetic units which perform arithmetic processes independently and in parallel based on a detection result of the detection unit, and output a signal for controlling the on-site equipment according to the results of operations of the arithmetic processes. The plurality of arithmetic units perform a matching process for harmonizing process statuses of the arithmetic processes of respective arithmetic units with each other when starting up the control devices, and after completing the matching process, respectively perform the arithmetic processes independently and in parallel.

Control device and nuclear power plant control system

A control system allows controlling a nuclear facility in an evacuation area. The control system includes a control device in ordinary use disposed in a non-evacuation area, an emergency control device&#x2014;for emergency in the evacuation area, a plant control facility connectable to the control device&#x2014;and the emergency control device, a signal switching unit that switches from a normal coupling to an emergency coupling based on an emergency switch signal, a first selector switch in the non-evacuation area, a second selector switch-in the evacuation area, an AND circuit configured to output the emergency switch signal to the signal switching unit in the case where the emergency switch signal is input from the first selector switch and the emergency switch signal is input from the second selector switch.

Control system for nuclear facility and control method for nuclear facility

A nuclear power plant control system () includes a control button () which receives an operation for controlling a control target device (), a notification lamp () which notifies that a control signal corresponding to the operation received by the control button () arrives at a predetermined position on a path connected from a control panel () to the control target device (), and a control signal inhibition unit () which inhibits a control signal from arriving at the control target device () in midstream between the predetermined position on the path and the control target device () in response to an operation received by a test permission button ().

Nuclear power plant control system and method of testing nuclear power plant

A nuclear power control system includes: a safety protection apparatus which outputs a first safety mode operating signal while outputting a first unsafety mode operating signal; a CCF apparatus that outputs a second safety mode operating signal; and a signal input/output circuit that is connected to the safety protection apparatus and the CCF apparatus. The signal input/output circuit includes an OR circuit that outputs a third safety mode operating signal based on the presence or absence of an input of the first safety mode operating signal and the second safety mode operating signal; a NOT circuit that is connected to the output side of the OR circuit; and an AND circuit that outputs a third unsafety mode operating signal, and the presence and absence of an input of a first unsafety mode operating signal.

Control system and method for nuclear power facility

A reactor shutdown system includes a reactor, a control-rod drive unit that can drive a control rod in pulling and inserting directions with respect to a fuel assembly, a power source that can supply power to the control-rod drive unit, and a power converter that is provided between the control-rod drive unit and the power source, in which when power supply is cut off, the control-rod drive unit inserts the control rod into the fuel assembly to stop nuclear reaction in the reactor, and the reactor shutdown system includes a reactor trip breaker provided between the power converter and the control-rod drive unit, a safety protection-system device that controls the reactor trip breaker to cut off power supply to the control-rod drive unit, and a CCF device that controls the power converter to cut off power supply to the control-rod drive unit.

Reactor shutdown system

A driving method and a driver circuit for improving the definition of display image on a plasma display device. In an initial state in an addressing discharge period, a scanning electrode is applied with a scanning base pulse at a first power supply potential. This suppresses a weak erroneous discharge between a scanning base pulse and a display data pulse. Next, the scanning electrode is applied with a scanning pulse. After the scanning pulse has been applied, the scanning electrode is applied with the scanning base pulse at a second power supply potential. In this way, the level of the scanning base pulse applied to the scanning electrode after the end of the application of the scanning pulse in the addressing discharge period is lower than the level of the scanning base pulse applied to the scanning electrode before the application of the scanning pulse. This ensures a potential difference between the scanning electrode and the sustain electrode, and facilitates the formation of a wall charge required for a sustain discharge in the next discharge sustain period.

Plasma display panel driving method, plasma display panel driver circuit, and plasma display device

A plasma display is provided with a plasma display panel, data drivers which apply data pulse to data electrodes of the plasma display panel, a control circuit which t controls an operation of the data drivers based on a video signal, and a protection signal output circuit. The protection signal output circuit outputs a protection signal to the control circuit when sum of currents supplied from the data drivers to the data electrodes within a time equal to one sub-field or more to less than one frame exceeds a previously set first specified current value. The protection signal restrains the operation of the data drivers.

Plasma display and driving method of the same

Two sustain driver circuits are provided: a first sustain driver circuit for both controlling the potential on the scan electrode side and effecting control such that, when the scan electrode side is at the power-supply potential, this potential is used to raise the potential on the sustain electrode side; and a second sustain driver circuit for both controlling the potential on the sustain electrode side and effecting control such that, when the sustain electrode side is at the power-supply potential, this potential is used to raise the potential of the scan electrode side. When the scan electrode side is at the power-supply potential, control is effected such that current flows from the first sustain driver circuit to the second sustain driver circuit by way of a third switching element and first coil, whereby the potential of the scan electrode side falls and the potential of the sustain electrode side rises. When the sustain electrode side is at the power-supply potential, on the other hand, control is effected such that current flows from the second sustain driver circuit to the first sustain driver circuit by way of a sixth switching element and a second coil, whereby the potential of the sustain electrode side falls and the potential of the scan electrode side rises.

Drive circuit for plasma display panel

A charge-collecting circuit is connected between a clamping circuit on the side of the sustain electrodes and a clamping circuit on the side of the scan electrodes so as to be parallel to a capacitance between said sustain electrodes and said scan electrodes. In write-discharge, sustain-discharge, and the like, when a sustain-electrode potential staying at the level of the ground potential with a switch S being turned ON is to be increased to the level of the power potential that is the same as the level of a scan-electrode potential staying at the power potential with a switch S being turned ON, the switch S is first turned OFF, a current is then applied to flow from the scan-electrode to the sustain-electrode side to thereby slowly increase the potential on the side of the sustain electrodes in the charge-collecting circuit. Then, the switch S is subsequently turned ON, thereby, the sustain-electrode potential is clamped to the power potential at the same level as that of the scan-electrode potential.

Driving method for plasma display panel

A plasma display capable of avoiding an increase in costs for manufacturing the plasma display by omitting use of a costly forced discharging circuit wherein electrical charges being left in an auxiliary high-voltage power source are discharged by detecting a drop in a voltage fed from a main high-voltage power source, while power is OFF, and changing a method of driving an X driver.

Method of driving plasma display and plasma display

A method and circuit for driving a plasma display panel are provided which are capable of preventing a useless display, irrespective of characteristics of a driving power source. In the method for driving the disclosed plasma display panel, a pulse having an erasing pulse which causes a maximum potential difference between sustaining electrodes being adjacent to each other to reach at least sustaining voltage is applied, immediately after power is applied, to a scanning electrode.

Method and circuit for driving plasma display panel, and plasma display device

For saving power by recovery and reuse of charge on data lines of a matrix display panel, a data line drive device, has a simplified circuit configuration. The device comprises a matrix display panel having a plurality of data lines DL; a data line drive circuit,A for driving said data lines DL, including a plurality of switch units QP,i, QN,i (i&equals;1 to N) interposed between a data voltage applying terminal P,and each of said data lines DL; electrostatic charge storage means C,L,for storing electrostatic charge on said data lines, which is connected to said data drive circuit,A; and a switch QS,i for recovering the charge, having a parasitic diode DS,i which is interposed between said data line drive circuit,A and each of said data lines, said charge recovering switch QS,i being brought into a conductive state when the charge on the data lines is recovered to said charge storing means C,L

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Tokyo, Japan

Hiroshi Shirasawa