Abstract: A distributed generation system is connected to an AC power line that provides AC electrical power from a source to a load. The distributed generation system includes a DC electrical power source, a capacitor for storing DC electrical power, a converter for converting electrical power stored in the DC electrical power source at a first voltage to a second, greater voltage for storage in the capacitor. The system includes an inverter for inverting the electrical power stored in the capacitor at the second voltage into AC electrical power having a peak voltage less than the second voltage. A controller is provided and operative for controlling the operation of the converter and the inverter to deliver electrical power stored in the DC electrical power source to the capacitor for delivery as AC electrical power to the AC power line.

Abstract: A distributed generation system is connected to an AC power line that provides AC electrical power from a source to a load. The distributed generation system includes a DC electrical power source, a capacitor for storing DC electrical power, a converter for converting electrical power stored in the DC electrical power source at a first voltage to a second, greater voltage for storage in the capacitor. The system includes an inverter for inverting the electrical power stored in the capacitor at the second voltage into AC electrical power having a peak voltage less than the second voltage. A controller is provided and operative for controlling the operation of the converter and the inverter to deliver electrical power stored in the DC electrical power source to the capacitor for delivery as AC electrical power to the AC power line.

Abstract: An active harmonic filter selectively sources current to or draws current from power lines. The active harmonic filter includes a controller which executes a predictor routine which predicts the current to be supplied to or drawn from the power line at a time t+.DELTA.t to reduce load induced phase differences between the line voltage and the line current. An integrating slow control routine integrates difference currents between actual line currents and desired line currents in equivalent segments of time in different cycles of the power line. The integrated differences may be combined with proportionally controlled difference currents to reduce or eliminate harmonic line currents. A current balancing routine enables the active harmonic filter to balance currents in two or more lines of a polyphase power line. The predictor, integrating slow control and current balancing routines, may be used singly or in combination to improve the condition of line currents on the power lines.

Abstract: An AC induction motor control apparatus includes the determination of the motor torque by one of the use of a torque versus dc input power lookup table for each of selected motor speeds below a predetermined speed and by a mathematical calculation of a plurality of power losses in relation to the dc input power and the inverter frequency for motor speeds above that selected speed.

Abstract: An AC induction motor is energized by a voltage fed inverter coupled with a DC power source and is controlled in response to a torque request signal that is provided to accelerate or decelerate the motor as desired to maintain a desired torque output. The motor is operated to have each of a power and brake operation below the base speed of the motor and to have each of a power and brake operation above the base speed of the motor.

Abstract: An AC induction motor brake control apparatus and method are provided for energizing the motor with an inverter supplied first voltage and an additional brake circuit supplied second voltage in phase with and additive to the first voltage as required to determine a desired brake torque above base speed operation.

Abstract: A control apparatus and method are provided for a load energized by an inverter coupled with a DC power source. The lag current angle between the current and the load voltage is utilized to determine when the output current is positive and when the output current is negative. The conduction times of the respective upper and lower gate turn off thyristors of each pole of the inverter are controlled in relation to the established current angle, with a provided modification of those conduction times being phased out in response to the desired output voltage for said load.

Abstract: AC induction motor energized by an inverter coupled with a DC power source. Upon shutdown of the inverter because of a fault condition or a rail gap between adjacent power sources, if the motor rotating frequency is greater than a minimum frequency then a decreased motor voltage is applied to the motor and increased as a ramp over a provided time delay period, after which the motor slip is controlled to provide a desired motor torque that is increased over a subsequent time delay period.

Abstract: An arrangement of interconnected timers is provided for operation with a microprocessor programmed to determine time delay counts that are fed out to these timers such that the timers can take care of the actual task of firing GTO inverter switches or not firing GTO inverter switches coupled with an AC traction motor for a vehicle. It is necessary to have correct transitions between the minus GTO switch and the plus GTO switch being ON for providing the desired motor voltage conditions with minimum electromagnetic interference in relation to the power supply. In addition the use of timer queues in complicated synthesis modes like the PWM and the quasi six-step operates to give the microprocessor adequate operating time for reasonable control signal time duration calculations. The timers are synchronized in hardware by a single crystal frequency, and they are synchronized in software such that the three phase independent waveforms stay 120.degree. apart.