Abstract: An apparatus controlling an electric vehicle motor and a method to reduce torque ripple using the same are provided. A field current flowing in a rotor field coil is controlled by generating a negative phase ripple current with respect to torque ripple according to each position of the rotor, allowing torque ripple of the motor to be reduced without degrading output torque. Additionally, in an operation region of a high torque section, torque ripple is reduced by controlling a field current by increasing an AC component of a negative phase ripple current, and in an operation region of a low torque section, torque ripple is reduced by controlling a field current by decreasing an AC component of a negative phase ripple current. That is, torque ripple of a motor can be reduced by controlling only a field current.

Abstract: Provided is a method for charging a battery that dynamizes the charging phase of the battery, thereby enabling optimum charging. The dynamization of the charging phase is intended to achieve effective mixing of the battery acid and/or depolarization of the electrodes and ultimately result in improved receiving of the charging current. In this context, the charging method can be carried out according to at least two different methods. In a first method, targeted discharges result in depolarization of the electrodes due to locally decreasing acid density, and in a second method the battery acid is reliably mixed as a result of temporary increasing of the charging voltage via the so-called gassing voltage of the battery. Both methods result in improved battery charging. In an embodiment of the method, the two methods are combined.

Abstract: A technique is provided for controlling operation of motors of different sized or ratings. Components used to apply and interrupt current to the motors may be shared in control devices for the different motors. The components may include contactors or circuit interrupters, and instantaneous trip devices. The components may be sized for the higher rated motors, and be oversized for the lower rated motors. Control circuitry permits the devices to be controlled in accordance with the characteristics of the particular motor to which the devices are applied, providing accurate circuit interruption while reducing the number of different components and component packages in a product family for the various motors.

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: In a power control system in which a time ratio control power circuit regulates the average current in an inductive load by repetitively connecting and disconnecting the load and a d-c power source, a variable impedance is connected in parallel circuit relationship with the load and is controlled so as to vary the inductive-resistive time constant of the load circuit. When necessary to rapidly reduce the current in the load, the impedance is made relatively large so that current rapidly decays. Conversely, the impedance is maintained at a minimum value when the load current is less than or substantially equal to a desired value.

Abstract: A circuit for generating a signal proportional to the average current of an inductive load supplied from a supply of intermittent electrical power and having a free-wheeling path through which load current flows during periods in which the load is not connected to the power supply, includes means to provide a first signal which is a function of the current in the free-wheeling path and second means to provide a second signal which is a function of the supply-load current. By appropriately combining the two signals an output proportional to the average load current is obtained. The output signal can be utilized for control functions such as controlling the operation of switching devices which, in turn, control the application of electrical power to a d.c. motor.