Abstract: A regenerative braking control apparatus for use with a motor driven by a D.C. power source. In response to a series of operating parameters, the control apparatus causes the motor to transition between a drive mode, a transient mode, a regulated current regenerative braking mode, and a constant PWM regenerative braking mode. In particular, the motor enters the drive mode in response to a request for an increase in speed, the motor enters the transient mode in response to a request for a decrease in speed, the motor enters the regulated current regenerative braking mode in response to a lapse of a predetermined time delay or in response to a request for a reduction in the magnitude of the previously requested decrease in speed, and the motor enters the PWM regenerative braking mode in response to a request to continue braking when the requested braking torque cannot be maintained.

Abstract: A braking control system for an electric automobile combines the use of mechanical braking and regenerative braking by a motor. Namely, a braking control system for the electrical automobile, which permits the combined use of regenerative braking and mechanical braking, is provided with target braking force setting unit (9) for setting a target braking force on the basis of a brake pedal stroke, regeneration control system (4A,5A) for setting a target regenerative braking force on the basis of the brake pedal stroke and then controlling regenerative braking by the motor in accordance with the target regenerative braking force, and mechanical braking control unit (24) for controlling operation of a mechanical brake system (B) in accordance with a difference between said target braking force and an actual braking force determined based on a detected deceleration of a vehicle.

Abstract: A braking system consisting of coil assemblies (6) which move in relation to a rotor magnet assembly (9) by using an actuator assembly (2). As the coil assemblies (6) are moved closer to the rotor magnet assembly (9), a current will develop in the coil assembly (6) which will generate a magnet field. This magnet field will in turn induce a torque on the rotor magnet assembly (9). The developed current can then be used to recharge the onboard energy storage system.

Abstract: A process and a device for monitoring and/or controlling the speed of rotation of an electric drive having an asynchronous motor equipped with a braking device (11) and connected via a frequency adapter (13) to an alternating current system (12), e.g. three-phase system, to provide safe lifting and lowering of a load. The maximum torque (16) produced by the drive for lifting the load is set to be smaller than a holding torque (17) needed by the braking device (11) to hold the load in a stationary position.

Abstract: A control circuit for an overhead crane motor includes a low supply voltage monitor to disconnect the motor from the control circuit and ensure brakes engage in the event of interruption of power supplied to the crane. A sensor circuit detects whether voltage supplied to the control circuit drops below a predefined threshold level which is greater than a voltage magnitude produced by the motorN operating in a regenerative mode during a power interruption. A switching circuit responds to sensing supply voltage below the threshold level by disconnecting electrical current to a relay coil which causes contacts to open which result in the motor being electrically disconnected from the control circuit. As a result of that disconnection, voltage produced by the motor operating in a regenerative mode does not inhibit electrically controlled mechanical brakes from engaging.

Abstract: A protecting method and apparatus for a regenerative resistor in which a regenerative resistor is satisfactorily protected from a thermal breakage caused by an over-regeneration by combining a projection of the regenerative resistor by a thermostat and a protection of the regenerative resistor by an analog simulation circuit and by coordinating protective regions of these two protections. The heat-responsive switch (2) stops power supply to a DC link (10) when the temperature of the regenerative resistor is increased to a predetermined value or greater value. The analog simulation circuit (1) is provided with a charge-discharge circuit to be charged and discharged in response to a regenerative pulse signal from a level detector (7), estimates the quantity of heat accumulated in the regenerative resistor (5) by means of the charge-discharge circuit, and stops power supply to the DC link (10) when a predetermined threshold value is exceeded by the estimated value.

Abstract: A system is provided for controlling a DC motor which is constructed to propel a golf car. The motor is a shunt wound motor having independently excited armature and field windings. The basic input to the armature of the motor is supplied through a pulse modulated chopper circuit which varies the width of the pulse in response to the throttle of the golf car. Full control of the input to the field winding is gained by the supply of power to an H bridge circuit. Armature current is continuously sensed to provide an indication of the status and performance of the car during operation. At a predetermined level of armature current the field current is adjusted to provide a higher torque at a specific speed. When armature current indicates a predetermined overspeed condition, field current is adjusted to enhance regeneration and the resultant braking. In addition, the stopped condition is continuously monitored.

Abstract: A motor control device for controlling the driving and regenerative operation of a motor includes CPU, ROM, RAM and a back-up RAM. An electric power is normally supplied from a subsidiary battery through a second regulator to the back-up RAM. An electric power is also supplied to the CPU, the ROM and the RAM through a main switch and a first regulator, on the one hand, and through the first regulator and a transistor which is turned ON when the number of revolutions of the motor becomes equal to or larger than a predetermined value, on the other hand. Therefore, even if the main switch is opened during traveling of a vehicle at a high speed, the counter-electromotive force of the motor can be decreased by the motor control device which is supplied with the electric power through the transistor to maintain its function, thereby preventing damage to an inverter.

Abstract: A system is provided for controlling a D-C motor which is constructed to propel a golf car. The motor is controlled to provide performance according to a predetermined field current map which calls for a particular performance response to specified performance events. The performance events are detected by sensing actual speed and armature current and the performance response is triggered by adjustment of the field current. A performance map correlating actual speed to various events and specifying the field current response is designed for the motor used. In addition an armature current performance map is similarly constructed correlating armature current to particular performance events.

Abstract: A circuit for controlling a motor having an armature and a series-wound, series-connected field coil that can be separately controlled during regenerative braking. The circuit includes a main switching circuit, an armature circuit, and a field circuit. The main switching circuit includes a first switch and a first diode parallel-connected to the first switch. The armature circuit includes a second switch parallel-connected to the armature and series-connected to the main switching circuit, and includes a second diode parallel-connected to the second switch. The field circuit includes a third diode parallel-connected to the field coil and series-connected to the armature circuit.

Abstract: An electric motor control for a series-wound DC motor for providing speed control and also for controlling regenerative braking. The regenerative braking is energized either when the accelerator pedal is released and/or when a brake pedal is depressed. In addition, the control circuit limits the total vehicle speed and brakes the vehicle if it is stopped and begins to roll due to gravity.

Abstract: A power control apparatus for controlling power supplied to an electric motor rotating a rotor employed in a centrifuge is provided. The power control apparatus includes first and second inverters and a smoothing capacitor disposed between the first and second inverters. In a motor power mode, the first inverter charges the smoothing capacitor with power supplied by an AC power supply, while the second inverter charges, in a motor braking mode, the smoothing capacitor with power regenerated by the motor during a braking operation for returning the regenerated power back to the AC power supply through the first inverter. An reactor is arranged between the AC power supply and the first inverter for reducing harmonic components contained in the current supplied from or back to the AC power supply.

Abstract: A motor control system for controlling power supplied to an electric motor rotating a rotor employed in a centrifuge is provided. The motor control system includes first, second, and third converters and first and second smoothing capacitors. In a motor power mode, the first converter operates to transfer the charged energy in the first smoothing capacitor to the second smoothing capacitor for providing power to the motor through the third converter, while the second converter transfers, in a motor braking mode, the charged energy in the second smoothing capacitor to the first smoothing capacitor to return the power regenerated by the motor during a braking operation to the AC power supply through the first converter. The second converter performs a function of providing an initial energizing energy to the motor for a given period of time at the start of the braking operation for stability of a power-regenerating operation of the motor.

Abstract: Electric motorized vehicular wheels with adjuncts use inside-out motors with interchangeable wire coil stators and interchangeable permanent and electromagnet rotors to roll and stop a load. A 360.degree. auto-steering wheel adjunct uses an inside-out motor with interchangeable stators and rotors attached to a wheel caster adjunct to steer a load. Shock absorption and wheel caster adjuncts regenerate KE continuously from road and tire bumps. Capacitorized hubcap adjuncts hold many kilowatts of electricity to roll, steer, and brake a load while recapturing all available KE from rolling, steering, and braking.

Abstract: A drive assembly comprises a DC electric motor and an integrated charger/controller/regenerator which includes a power module, a step-up module and a control circuit. The input of the power module is connected to an electric power source during charging, and to the DC motor during regenerative braking. The input of the step-up module is connected to the power module, and the output is connected to the battery. The control circuit includes a switch, and has three modes of operation: driving, regenerative braking and charging. During driving, the switch connects the battery to the power module input and the power module output to the DC motor. During regenerative braking, the switch connects the DC motor to the power module input and the power module output to the step-up module input, and the step-up module output charges the battery. During charging, the switch connects the power module output to the step-up module input, and the step-up module output charges the battery.

Abstract: A system and methods that provide for battery regeneration in electric vehicles without employing brake blending. Wheel speed sensors provide speed inputs to a controller, for example, that are processed to control the torque commands issued to a motor of the vehicle, which allows a higher level of battery regeneration without causing drive wheels to lock up. In the present invention, speed inputs derived from the wheel speed sensors are sampled. The absolute value of the difference between the input signals derived from the wheel speed sensors is compared to a predetermined difference threshold. If the absolute value of the difference between the input signals is less than the predetermined difference threshold, a regeneration torque command is generated to control the torque output of the motor that is equal to a current value of the regeneration torque command.

Abstract: A drive assembly comprises a DC electric motor and an integrated charger/controller/regenerator which includes a power module, a step-down module and a control circuit. The input of the power module is connected to an electric power source during charging, and to the DC motor during regenerative braking. The input of the step-down module is connected to the power module, and the output is connected to the battery. The control circuit includes a multiplicity of switches, and has three modes of operation: driving, regenerative braking and charging. During driving, the switches connect the battery to the power module input and the power module output to the DC motor. During regenerative braking, the switches connect the DC motor to the power module input and the power module output to the step-down module input, and the step-down module output charges the battery. During charging, the switches connect the power module output to the step-down module input, and the step-down module output charges the battery.

Abstract: A motor controller includes a power source VG for driving a motor 1, a power source VRG for regenerating energy generated in the motor 1, and a power converter for transferring energy from the power source VRG to the power source VG. Windings of the motor are connected, at their opposite ends, to the power source VG and collectors of transistors TR1 to TR3, respectively. Diodes D1 to D3 are connected to nodes of the windings and the transistors TR1-TR3 such that magnetic energy generated in the motor 1 is supplied to the power source VRG. This configuration enables the motor controller to have a reduced number of transistors for driving the windings, and the power sources to be effectively utilized. Further, the motor controller can use a discharge circuit of small power consumption type, which can reduce heat generated in the motor controller.

Abstract: The invention is made to provide a reliable driving system by solving the problem of the conventional apparatus caused by unstable current in the chopper transistor located at the low end of the field winding and armature winding. The over drive control apparatus of the direct current series motor of the present invention, including the field winding and armature winding and driven by power from the battery, comprises a chopper transistor to which the battery is applied, and an over drive contactor connected between the chopper transistor and the field windings to switch the battery power from the chopper transistor to the field winding.

Abstract: A braking force controller for an electric vehicle properly carries out an anti-lock braking operation by keeping a slip ratio in a stable range. The vehicle has a motor 1 to drive wheels. A central controller 4 calculates regenerative energy according to output signals from an ammeter 51 and a voltmeter 52. If a brake sensor 62 detects a sudden braking operation, the central controller 4 controls the regenerative braking force of the motor 1 through a motor controller 2, to maintain the regenerative energy around a maximal value.

Abstract: A series motor for an appliance or tool, such as a circular saw, includes a regenerative braking circuit having brake windings in addition to the run windings. One of the brushholder assemblies includes a push-away feature for separating one of the brushes from the commutator prior to the time the brush could wear to an extent that direct current reversal might not be available to achieve the desired braking action.

Abstract: A regenerative braking control system consumes energy generated in a period corresponding to an angle .theta..sub.1 which starts in a half of a period of an AC voltage produced in a drive motor during the braking of the drive motor. The regenerative braking control system also consumes energy generated in a period corresponding to an angle .theta..sub.2 that ends at the end of a half of a period of the AC voltage. The regenerative rate of braking control system utilizes a current induced in the driving coils of the drive motor at the end of the period corresponding to the angle .theta..sub.1 to recharge a battery. By utilizing two periods to carry out the regenerative braking process, the recharging energy and the braking force can be controlled individually. Moreover, a controller monitors the electric control system to determine whether a malfunction is present. If a malfunction is detected, an electrical brake electrically brakes the drive motor.

Abstract: A system is provided for controlling a DC motor which is constructed to propel a golf car. The motor is a shunt wound motor having independently excited armature and field windings. The basic input to the armature of the motor is supplied through a pulse modulated chopper circuit which varies the width of the pulse in response to the throttle of the golf car. Full control of the input to the field winding is gained by the supply of power to an H bridge circuit. Armature current is continuously sensed to provide an indication of the status and performance of the car during operation. At a predetermined level of armature current the field current is adjusted to provide a higher torque at a specific speed. When armature current indicates a predetermined overspeed condition, field current is adjusted to enhance regeneration and the resultant braking. In addition, the stopped condition is continuously monitored.

Abstract: In a circuit having an electromechanical transducer, such as a motor (22), a control switch (24) is controlled by a control circuit (26) to connect the motor to, and disconnect from, a battery (12). When control switch opens, thereby disconnecting the motor from the battery, the momentum achieved by the motor tends keep the motor turning, causing the motor to behave like a generator. A switch network (28) connects a first capacitor (30), which is initially discharged, across the motor at the same time the control switch disconnects it from the battery. The momentum of the motor, and any attached mechanical system (32), generates a transient charge which is collected by the first capacitor. When the voltage produced by the collected charge reaches a peak, the switch network disconnects the first capacitor from the motor, reorients the first capacitor, and waits to apply the voltage to the motor.

Abstract: Disclosed is a regeneration device used for industrial electric vehicle including a main controller having a microcomputer, a contactor circuit having forward and reverse current paths comprised of a DC choke coil, a battery, and an acceleration switch connected to the batter.

Abstract: A pulsing drive system delivers pulsed power signal of the driven wheels of a vehicle for improving the efficiency internal combustion or an electric motor driven vehicles. A controller receives signals such as velocity and demand, and communicates to a means for selectively communicating energy wherein the means for selectively communicating energy converts the pulse signal to a correspondingly conditioned power pulse for powering the vehicle. When combined with a plurality of motors sized with optimal horsepower ranges according to a binary array, an arrangement of such motors provides for an optimally efficient operation of the vehicle by bringing on-line strategically selected combinations of the motors. A control system selectively brings on-line the multiple motors.

Abstract: A device for controlling an electric vehicle motor that optimally discharges a smoothing capacitor, connected to the input terminals of an inverter in accordance with the condition of an electric vehicle. The device includes a motor drive means, the smoothing capacitor connected in parallel with the motor drive means, switching means operating in connection with an operation switch operated by the vehicle operator, discharging means for discharging the smoothing capacitor, draw detecting means, and discharge restricting means. The system opens the switching means to shut off output from the battery and to discharge the smoothing capacitor when the switching means is open, but restricts discharging during a towing or drawing condition of the electric vehicle.

Abstract: A method and circuit for braking a forward rotation of a rotor of a polyphase DC motor. A commutation sequencer is incremented by several phases to produce an incremented commutation sequence to produce a magnetic flux vector that lags a magnetic pole of the motor. Driving currents are applied to coils of the motor in accordance with the incremented commutation sequence to brake the rotor. The method is implemented in a circuit that has a sequencer for incrementally generating sets of commutation signals to select stator coils for energization to rotate the rotor. A power stage to which the commutation signals are applied energizes the selected coils in accordance with the commutation signals. A circuit interrupts the energization of the selected coils and the commutation sequence is altered to produce a sequence that produces a negative torque on the rotor.

Abstract: A method bridges gaps in a power supply for electrical, converter-fed rail vehicles having front and rear ends with front and rear current collectors, as seen in a travel direction, for making contact with the power supply. The method includes switching a traction converter from a traction mode to a regenerative braking mode, that is to say a generator operation or from a braking mode to the regenerative braking mode. The switching takes place over a period during which the rail vehicle travels a distance. If possible, the distance is only slightly shorter than a distance between the front and rear current collectors. This occurs as soon as the front current collector is not in contact with the power supply.

Abstract: A power control apparatus for controlling power supplied to an electric motor rotating a rotor employed in a centrifuge is provided. The power control apparatus includes first and second inverters and a smoothing capacitor disposed between the first and second inverters. In a motor power mode, the first inverter charges the smoothing capacitor with power supplied by an AC power supply, while the second inverter charges, in a motor braking mode, the smoothing capacitor with power regenerated by the motor during a braking operation for returning the regenerated power back to the AC power supply through the first inverter. An reactor is arranged between the AC power supply and the first inverter for reducing harmonic components contained in the current supplied from or back to the AC power supply.

Abstract: A separately excited DC motor system is arranged to provide operation in a smooth, continuous electrical retarding mode. A series contactor connects the motor armature to a DC power source and is controlled so as to immediately open upon sensing of a need for electrical braking. Concurrently, power to the motor field is reversed so that no additional changes are required to brake to zero speed. Field current is modulated to control armature current so as to control braking effort. When speed falls below a value necessary to maintain armature voltage above battery voltage, the armature is cyclically short-circuited to boost armature current so that when the short-circuit is removed, the armature reactance forces current to continue for regeneration.

Abstract: When a voltage level determinator judges from the terminal voltage of a smoothing capacitance that a battery is in an over-charged state and cannot receive regeneration energy, a regeneration/free-wheel mode selector switches to a free-wheel mode for consuming the energy of the battery. For this purpose, a torque reducing signal generator executes a control in which only a magnetizing component of current flows through the primary winding and no driving force is generated in the motor, with the result that the energy of the battery is consumed as heat loss inside the motor. Then, when the over-charged state is eliminated and the energy receiving capability of the battery is recovered, the regeneration/free-wheel mode selector switches the mode to the regeneration mode to obtain regeneration braking.

Abstract: A synchronous motor control system controls a synchronous motor on an electric vehicle for propelling the electric vehicle in a propulsive mode or regenerating electric energy in a regenerative model. The synchronous motor control system has a rotational speed sensor for detecting a rotational speed of the synchronous motor, an accelerator for producing a torque command signal, and a driver connected between a battery on the electric vehicle and the synchronous motor for operating the synchronous motor in either the propulsive mode or the regenerative mode. A controller is responsive to the rotational speed detected by the rotational speed sensor and the torque command signal produced by the accelerator for controlling the driver to operate the synchronous motor in either the propulsive mode or the regenerative mode.

Abstract: A motor control circuit is disclosed for providing a continuously variable regeneration control. The control circuit includes a microcomputer for generating a power regeneration command signal and a motor command signal, and an armature circuit for use with DC and induction motors. The armature circuit is responsive to the motor command signal for operating the controlled motor in a motor drive mode. The armature circuit is further responsive to the power regeneration command signal for controlling the degree of power regeneration. The armature circuit includes a deadtime generator, responsive to the motor command signal for generating a pair of complementary motor drive signals, the inverted signal of the pair having deadtime. The inverted motor drive signal with deadtime is AND'ed with the power regeneration command signal to produce a power regeneration drive signal. The non-inverted motor drive signal and the power regeneration drive signal are applied to a Class C two-quadrant chopper drive circuit.

Abstract: AC input voltage is lowered at a transformer, rectified at a rectifying circuit, then smoothed at a smoothing circuit, and thus produced DC voltage is supplied to an inverter which drives a motor. The rectified DC voltage is provided to a DC/DC converter to generate power supply for a magnetic bearing, and DC power supply for controlling the magnetic bearing is generated at a DC/DC converter. During the power failure regenerative electric power from motor is provided to DC/DC converter to produce power voltage for the magnetic bearing, and DC voltage for controlling the magnetic bearing is provided from DC/DC converter.

Abstract: An electrical system that receives power from an external power source that includes an inverter (U1). The inverter (U1) receives DC power and generates a variable voltage output. First and second current collectors (30, 32) connected to the inverter (U1) and receive the DC input through contact with positive and negative poles of the external power source. A motor (M1) and an internal DC bus (+,-) are connected to the current collectors (30,32). A protection circuit is connected across the internal DC bus (+,-), and protects the inverter (U1) from connection to an input of improper polarity. The protection circuit permits the inverter (U1) to deliver a DC output to the power source during a regenerative braking operation.

Abstract: The invention provides a brake control apparatus for an electric motor vehicle that can control a charging current depending on a charging state of a dc power supply to avoid overcharging it. In regenerative braking, according to the invention, the charging state of a battery is detected by a charging state detector, which sends a detection signal to a control unit. When the state of charge of the battery exceeds a predetermined level, the control unit controls operating parameters of an inverter so that the charging current to the battery is decreased. If, however, insufficient torque results, the control unit turns on an electric load to increase the control torque. If further load absorption is needed, the control unit turns on electric braking means.

Abstract: A braking and auxiliary driving unit for an internal combustion engine which produces braking and auxiliary motive power by converting electrical energy in both directions between a polyphase AC circuit of a squirrel-cage polyphase induction machine linked to the rotary shaft of the internal combustion engine and the DC circuit of an electricity storage means, the electricity storage means comprises an electrostatic capacitive circuit. A low-voltage storage battery is provided in addition to this electrostatic capacitive circuit, and this can be coupled to the electrostatic capacitive circuit by a bidirectional DC-to-DC converter.

Abstract: The present invention relates to a power source regenerative apparatus which prevents distortion of a voltage regenerating in the power source from being caused. An inverter transforms induction electromotive force caused in regenerating the power source, namely in decelerating the motor, into a direct current. A timing adjusting device outputs a regenerative signal ST at a predetermined timing before the potential of one phase indicative of the maximum potential in three-phase supply voltages becomes the same potential as that of another phase. Based on the regenerative signal ST, a converter converts the transformed direct current into an alternating current, and regenerates it to the power source.

Abstract: In an electric system for an electric vehicle, DC power of a main battery is converted into AC power by an inverter which has a power regenerative function. At startup, the system charges an input smoothing capacitor on the DC side of the inverter through an initial charging circuit with an initial charging switch and resistor. A main circuit switch that can stop current is connected between the main battery and the inverter. A rheostatic braking circuit with a rheostatic braking switch and a braking resistor is connected to the DC input side of the inverter for rheostatic breaking when required. Rheostatic braking takes over after regenerative braking when the main battery loses its power absorption capability, with the main circuit switch off. Semiconductors can be used as switches, and can be placed on a cooling body or modularized. Low-noise wires can be used to reduce noise.

Abstract: A method and circuit for braking a forward rotation of a rotor of a polyphase DC motor. A commutation sequencer is incremented by several phases to produce an incremented commutation sequence to produce a magnetic flux vector that lags a magnetic pole of the motor. Driving currents are applied to coils of the motor in accordance with the incremented commutation sequence to brake the rotor. The method is implemented in a circuit that has a sequencer for incrementally generating sets of commutation signals to select stator coils for energization to rotate the rotor. A power stage to which the commutation signals are applied energizes the selected coils in accordance with the commutation signals. A circuit interrupts the energization of the selected coils and the commutation sequence is altered to produce a sequence that produces a negative torque on the rotor.

Abstract: A regenerative ac to dc convertor includes a thyristor bridge invertor and a rectifier having a dc link capacitor. A second capacitor is connected across the invertor. In a regenerative braking mode of the motor the invertor is arranged to return energy from the second capacitor to the ac supply. Circulating currents are inhibited by diodes connecting the dc link and second capacitor. A first diode is arrange to conduct from the positive terminal of the second capacitor to the positive terminal of the dc link capacitor. A second diode is arranged so that it conducts from the negative terminal of the dc link capacitor to the negative terminal of the second capacitor.

Abstract: A reluctance type motor and a brushless DC motor having large torque and good efficiency in a high-speed region.When one exciting coil or armature coil is deactivated, magnetic energy stored in the magnetic core is prevented from returning to the electric power source side by means of a back-flow preventing diode. The magnetic energy is charged in a small-capacitance capacitor so as to hold it at a high voltage, thereby causing exciting current to decrease steeply. After a predetermined time has elapsed, a next exciting or armature coil is activated. In this case, the high voltage charged in the capacitor is applied, so that the exciting current builds up sharply.

Abstract: A system (20) for controlling deceleration of a motor (22) during an abrupt power-off condition includes a processor (40), a motor control circuit (50), and a secondary power source (70). During normal power-on operation and based on currently prevailing operation parameters, processor (40) routinely generates a contingent motor-governing deceleration signal for potential use in governing motor (22) should the power-off condition occur. In response to the occurrence of a power-off condition, motor control circuit (50) controls motor (22) in accordance with the contingent motor-governing deceleration signal to achieve orderly deceleration. Secondary power supply circuit (70) provides power to motor control circuit (50) during the power-off condition.

Abstract: An analog DC link bus voltage in an induction motor drive is converted to a digital DC link bus voltage so that if the DC link bus voltage exceeds an ON voltage threshold of a switch and this condition exists a holding time later, the switch closes, thereby allowing regenerated power in the DC link to be dissipated in a resistor connected across the DC link. And if the DC link bus voltage falls below an OFF voltage threshold and that condition exists a latching time later, the switch is opened so that no regenerated power may be dissipated through the resistor.

Abstract: A large-capacity capacitor (C1, C2) is connected in series and/or parallel with a battery (11). A voltage sensor (9, 10) is provided to the battery and/or the large-capacity capacitor to detect their terminal voltages. Input and output currents are limited between at least one of a motor driving circuit and the large-capacity capacitor and the battery on the basis of the detection signals from the voltage sensor. When the terminal voltage of the large-capacity capacitor is equal to or higher than a predetermined value, a current flowing from the motor driving circuit to the large-capacity capacitor is limited.

Abstract: An electrical traction system notably for automobiles which has (a) at least one recharging supply source; (b) at least one synchronous electrical motor with a stator having a plurality of spatially offset stator windings, a commutating device with choppers for routing a current given by the supply source into the stator winding in order to create a rotating magnetic field, and a rotor; (c) a circuit for charging the supply source including a transformer, which transformer includes the stator windings; and (d) at least one converter for charging an auxiliary battery.

Abstract: A motor drive includes an invertor (5) with which a motor (6) is rotated at a variable speed. To suppress noises caused by ripple components contained in currents flowing in phase coils of the motor, the invertor (5) is controlled so as to direct a commuting current flowing from the phase coils to a d.c. power source (1) and at a time when the motor is decelerating to circulate in a path including the phase coils and the switching transistors of the invertor (5). This control is performed when the commuting currents fall below a predetermined level.

Abstract: A dynamic braking grid arrangement for reducing EMI generated by dynamic or partial regenerative electrical braking of an electric traction motor powered vehicle coupled to a wayside power source by a third rail or catenary. The grid arrangement comprises a high-power dissipation resistance grid having a plurality of separately defined resistance elements, each having a generally elongate configuration. Mounting means support each of the grid elements adjacent to and parallel with each other of the elements. A plurality of electrical conduction devices connect the elements into an electrical circuit such that current passes through at least one element in a first direction and through at least one adjacent element in a second opposite direction such that EMI generated by any one element is substantially cancelled by EMI generated by an adjacent element.

Abstract: An electric braking system controls the vehicle brake torque based on the pressure applied by the vehicle operator to the vehicle brake pedal and a moving vehicle brake system gain to provide normal power assisted braking while the vehicle is moving. The deviation of the vehicle braking condition from a level incline and lowest vehicle weight (LVW) is determined based upon a determined percent difference between the actual vehicle deceleration while the vehicle is being braked to a stop and an expected deceleration that would result from the total brake torque, a level road surface, and the vehicle weight at LVW. The expected deceleration is determined by determining the total vehicle brake torque represented by the sum of the brake torques applied by the individual wheel brakes and dividing by the LVW of the vehicle.