摘要:
A power distribution system includes an ac power source; a power bus connected to the ac power source; a capacitor bank shunt-connected to the power bus; and an active filter shunt-connected to the power bus. The active filter includes current sensors, an inverter and an inverter control. Each current sensor senses current flowing through a corresponding capacitor of the capacitor bank. The inverter control, in response to the current sensors, controls the inverter to inject harmonic currents into the power bus.
摘要:
A power distribution system includes an ac power source; a power bus connected to the ac power source; a capacitor bank shunt-connected to the power bus; and an active filter shunt-connected to the power bus. The active filter includes current sensors, an inverter and an inverter control. Each current sensor senses current flowing through a corresponding capacitor of the capacitor bank. The inverter control, in response to the current sensors, controls the inverter to inject harmonic currents into the power bus.
摘要:
An ac-to-ac power converter includes a source-side inverter that is operated in current mode and a drive side inverter that is operated in commutation mode. The source side inverter performs current regulation during a first portion of each modulating cycle and space vector modulation during a second portion of each modulating cycle.
摘要:
A variable speed drive system for an induction motor is disclosed which utilizes power factor correction capacitors to allow an induction motor to be driven by a line-commutated inverter using variable phase angle triggering of the thyristers in the inverter to compensate for frequency-induced changes in the operating point of the system.
摘要:
An electrical power system includes an electric power source providing AC power to a load. A wideband voltage controller provides a wideband control signal vector to the electric power source. A fundamental component removal module interfaces to the AC power, receiving a fundamental component Park vector of the AC voltage, and providing a resonant frequency content in Park vector format of the AC current. A narrow band voltage regulator uses a resonant component Park vector of the AC current and the resonant frequency content in Park vector format to provide a narrow band output vector signal. A dead band compensating circuit rotates narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector to the electric power source. The wideband control signal vector and compensated control signal vector are used to regulate the AC power so that the resonant frequency content is attenuated.
摘要:
A drive arrangement for a fault tolerant variable speed induction motor provides a pair of current (torque and flux) command signals. The current command signals are converted to a three-phase output with sinusoidally varying signals. The three-phase output is modified to enable the motor to operate in the event one of the motor phases is open or disconnected. The modified three-phase output is used to provide first, second and third gate logic signals which are used for driving the motor.
摘要:
Power factor control of a pulse width modulated inverter supplied permanent magnet motor is achieved by using Park Vectors for automatically adjusting a pulse width modulating signal for approximately unity power factor, thereby avoiding the heretofore required manual adjustment during operation of the motor for power factor changes in accordance with changes in EMF and motor resistance.
摘要:
A method and apparatus for converting the output of a polyphase AC machine into a DC current by capacitor assisted line commutation within the rectifying circuitry.
摘要:
An electrical power system includes a switched reluctance machine/inverter adapted for providing DC power to a load; a voltage controller, which provides a control angle &thgr;C to the switched reluctance machine/inverter; an extraction module having an interface to the DC power and providing a resonant frequency content in Park vector format of a resonant frequency content at the interface; a phase locked loop, which provides a transformation angle &thgr; from the resonant frequency content in Park vector format; a resonant frequency voltage controller, which uses the resonant frequency content in Park vector format and the transformation angle &thgr; to provide a control angle &Dgr;&thgr; to the switched reluctance machine/inverter so that the control angle &thgr;C and the control angle &Dgr;&thgr; can be used to regulate the DC power and the resonant frequency content is attenuated in regulating the DC power.
摘要:
A load site voltage regulation control system. The load site receives electrical power from a utility over transmission lines. The load site also receives electrical power from a local generator unit operating with an inverter. The local generator unit and inverter arc coupled to the load by an EMI filter and a transformer. Voltage at the load is controlled by adjusting the inverter voltage using an inverter voltage command. The inverter voltage command is based on load voltage, inverter voltage, EMI filter voltage, utility supplied current, and inverter current. In one embodiment, the inverter voltage is adjusted to minimize utility supplied reactive and real power and to actively dampen EMI filter voltage, with the inverter voltage command being developed though a multi-loop PPI control system.