Abstract: A field winding type rotary electric machine includes a motor generator; a field current detection unit; a field current control unit which controls a field current; a field current limiting determination section which calculates a field current integration value and determines whether or not the field current integration value reaches a predetermined field current integration threshold value; and a field current limiting command section which, when it is determined that the field current integration value reaches the predetermined field current integration threshold value, outputs a command which sets the field current to be lower than or equal to a predetermined field current limiting value to the field current control unit during a predetermined limiting time, and outputs a command which changes the predetermined limiting time depending on the field current. Accordingly, a temperature rise of the machine is suppressed and limiting of the field current can be released as needed.

Abstract: To provide an upper limit of a generated voltage or generated torque, to thereby prevent the occurrence of an overvoltage or excessive torque during power generation, a control selection section (308) chooses and outputs a minimum value between a control output of a generated voltage control section (306) for controlling a field current so that a B-terminal voltage of a polyphase AC generator-motor coincides with a generated voltage command and a control output of a generated torque control section (307) for controlling, based on the B-terminal voltage and a rotation speed, the field current so that generated torque of the polyphase AC generator-motor coincides with a generated torque command.

Abstract: To provide an upper limit of a generated voltage or generated torque, to thereby prevent the occurrence of an overvoltage or excessive torque during power generation, a control selection section (308) chooses and outputs a minimum value between a control output of a generated voltage control section (306) for controlling a field current so that a B-terminal voltage of a polyphase AC generator-motor coincides with a generated voltage command and a control output of a generated torque control section (307) for controlling, based on the B-terminal voltage and a rotation speed, the field current so that generated torque of the polyphase AC generator-motor coincides with a generated torque command.

Abstract: In an electric power converter for a vehicle which is connected to an alternating-current generator for a vehicle and performs synchronous rectification, switching mistakes are reduced and efficiency is improved by setting an optimal control allowance time in generating a switching timing signal from a diode ON signal. A control allowance according to the operating state of a generator can be determined by obtaining a control allowance time as a sum of a control delay time which is constant irrespective of the operating state of the generator, and an allowance time which varies depending on the operating state of the generator. Thereby, optimal switching timing is obtained and the reduction of switching mistakes and an improvement in efficiency are performed.

Abstract: Generation voltage control or generation torque control is performed as suitable control based on an external command or a load of a generator motor, to thereby prevent a rapid change of a generation torque or excessive power generation. A power converter control apparatus includes: a power conversion unit including a bridge circuit for controlling energization of an armature winding and a field circuit for controlling energization of a field winding; and a control device including B-terminal voltage detection means, field current detection means, generation voltage control means, generation torque control means, and control selection means. The control selection means selects the one of the generation voltage control means and the generation torque control means based on one of a command from an outside and a load of the generator motor.

Abstract: A field winding type rotary electric machine includes: a controller; a field current integration portion provided in the controller to calculate an integral value by integrating an excessive field current exceeding a field current threshold; a field current limiting portion provided in the controller and carrying out limiting processing to limit a field current to or below a predetermined value when the integral value reaches an integral value threshold defined as a reference value at or above which the field current is limited; a controller power supply connection switch switched ON and OFF for power feeding to the controller; a controller power supply connection determination portion switching ON and OFF the controller power supply connection switch; and a power feeding ON state maintaining portion maintaining an ON state of the power feeding to the controller from start to end of the limiting processing by the field current limiting portion.

Abstract: A power-generation motor control system is a control system that controls a power-generation motor provided with an armature and a magnetic-field winding, and is characterized in that when the power-generation motor is operated as a motor, before a power source energizes the armature, a preliminary excitation current, with the value of which the induction voltage across the armature does not exceed the voltage of the power source, is applied to the magnetic-field winding in accordance with the rotation speed of the power-generation motor so that preliminary excitation of the power-generation motor is performed.

Abstract: A power converter control apparatus includes a power converter part having a bridge circuit formed of a switching element and a field circuit controlling conduction of a field winding in an AC generator, and a control apparatus part having a field current detector, a temperature detector detecting a temperature of a generator part, the power converter part, or the control apparatus part, a field current instruction computation portion computing a field current instruction value of the generator, a temperature rise suppression portion computing a generated current suppression value on the basis of an output of the temperature detector and computing a field current suppression value on the basis of the computed generated current suppression value, a field current instruction selection portion selecting the field current instruction value or the field current suppression value whichever is the smaller, and a field current control portion controlling a field current.

Abstract: A field winding type rotary electric machine includes a motor generator; a field current detection unit; a field current control unit which controls a field current; a field current limiting determination section which calculates a field current integration value and determines whether or not the field current integration value reaches a predetermined field current integration threshold value; and a field current limiting command section which, when it is determined that the field current integration value reaches the predetermined field current integration threshold value, outputs a command which sets the field current to be lower than or equal to a predetermined field current limiting value to the field current control unit during a predetermined limiting time, and outputs a command which changes the predetermined limiting time depending on the field current. Accordingly, a temperature rise of the machine is suppressed and limiting of the field current can be released as needed.

Abstract: In an electric power converter for a vehicle which is connected to an alternating-current generator for a vehicle and performs synchronous rectification, switching mistakes are reduced and efficiency is improved by setting an optimal control allowance time in generating a switching timing signal from a diode ON signal. A control allowance according to the operating state of a generator can be determined by obtaining a control allowance time as a sum of a control delay time which is constant irrespective of the operating state of the generator, and an allowance time which varies depending on the operating state of the generator. Thereby, optimal switching timing is obtained and the reduction of switching mistakes and an improvement in efficiency are performed.

Abstract: Generation voltage control or generation torque control is performed as suitable control based on an external command or a load of a generator motor, to thereby prevent a rapid change of a generation torque or excessive power generation. A power converter control apparatus includes: a power conversion unit including a bridge circuit for controlling energization of an armature winding and a field circuit for controlling energization of a field winding; and a control device including B-terminal voltage detection means, field current detection means, generation voltage control means, generation torque control means, and control selection means. The control selection means selects the one of the generation voltage control means and the generation torque control means based on one of a command from an outside and a load of the generator motor.

Abstract: A reduction purification method of a nitrogen oxide-containing exhaust gas by contacting said nitrogen oxide-containing exhaust gas with a catalyst in an oxidative atmosphere in which an excess amount of oxygen is present and in the presence of a least one reducing agent selected from the group consisting of a hydrocarbon and an oxygen-containing organic compound, wherein said catalyst comprises an alumina having supported thereon (a) tin and (b) at least one selected from the group consisting of ruthenium, palladium, rhodium and indium.

Abstract: A reduction purification method of a nitrogen oxide-containing exhaust gas by contacting said nitrogen oxide-containing exhaust gas with a catalyst in an oxidative atmosphere in which an excess amount of oxygen is present and in the presence of at least one reducing agent selected from the group consisting of a hydrocarbon and an oxygen-containing organic compound, wherein said catalyst comprises an alumina having supported thereon (a) tin and (b) at least one selected from the group consisting of ruthenium, palladium, rhodium and indium.

Abstract: A process for removing nitrogen oxide from exhaust is disclosed, comprising contacting exhaust containing nitrogen oxide with an alumina catalyst which contains not more than 0.5% by weight of an alkali metal and/or an alkaline earth metal and has a total pore volume of from 0.48 to 1.2 cm.sup.3 .multidot.g.sup.-1 with 0.26 to 0.6 cm.sup.3 .multidot.g.sup.-1 of the total pore volume being formed of pores of not greater than 80 .ANG. or has a volume of pores formed of pores of not greater than 60 .ANG. of from 0.06 to 0.2 cm.sup.3 .multidot.g.sup.-l and which may have supported thereon tin in an oxidative atmosphere containing excess oxygen in the presence of a hydrocarbon or an oxygen-containing organic compound.

Abstract: A novel catalyst for catalytic reduction of nitrogen oxide using a hydrocarbon as a reducing agent is provided, which comprises (a) at least an element of the platinum group selected from the group consisting of platinum, iridium, rhodium and ruthenium and (b) gold, and which may further comprises (c) at least a metallic oxide selected from the group consisting of cerium oxide, lanthanum oxide, neodymium oxide, germanium oxide and gallium oxide.

Abstract: A catalyst for catalytic reduction of nitrogen oxide using at least one reducing agent selected from the group consisting of a hydrocarbon and an oxygen-containing organic compound is described, which includes an oxide represented by formula (V):A.sup.5.sub.x B.sup.3.sub.3-x C.sup.4.sub.3 O.sub.7 (V)wherein A.sup.5 represents at least one element selected from the group consisting of La, Y, Ce, Pr, Nd, Sm, Eu, and Gd; B.sup.3 represents at least one element selected from the group consisting of Ba, Sr, Ca, Mg, Pb, Zn, and Ag; C.sup.4 represents at least one element selected from the group consisting of Mn, Co, Fe, Ni, Cr, Cu, V, Mo, W, Ti, Zr, Nb, Pd, Rh, Ru, and Pt; and x is a number of from 0 to 1, supported on a solid acid carrier.

Abstract: A process for reducing nitrogen oxides to nitrogen from exhaust gases is disclosed, which involves bringing an exhaust gas containing nitrogen oxides into contact with at least one catalyst from proton-type zeolites, zeolites of an alkali metal exchanged form and acidic metal oxides, by reaction with a hydrocarbon or an oxygen-containing organic compound in an oxidizing atmosphere containing excess oxygen. A process which further involves bringing the exhaust gas into contact with an oxidizing catalyst subsequent to the above process.

Abstract: A process for removing nitrogen oxides from an exhaust gas by bringing the exhaust gas containing nitrogen oxides into contact with at least one catalyst selected from a polyvalent metal phosphate, a polyvalent metal sulfate or an aluminate of a transition metal of the 4th period of the Periodic Table in an oxidizing atmosphere containing excess oxygen and in the presence of a hydrocarbon or an oxygen containing organic compound. There is also disclosed a process for removing nitrogen oxides from an exhaust gas which comprises bringing the exhaust gas into contact with the above catalyst and then with an oxidation catalyst.