Abstract:
A slip recovery system for a wound rotor induction motor is disclosed in which first and second inverters, connected in series, are coupled to the rotor of the induction motor. A switch is arranged in parallel with the second of these inverters, the switch being in the open position during starting and stopping of the motor, and being closed to short out the second inverter during normal running conditions. Thus, the first inverter need have only a voltage rating of such magnitude so as to satisfy the expected operating range for the wound rotor, while the second inverter need have only a voltage rating of sufficient magnitude to satisfy the additional capacity requirements for stopping and starting service. Thus, lower rated inverter components may be used with lower initial costs as well as concomitant lower operating costs.
Abstract:
A thyristor starting device (100) includes: a converter (1) which converts AC power supplied from an AC power source (e1) into DC power; a DC reactor (3) which smooths a DC current; an inverter (2) which converts the DC power provided from the converter (1) through the DC reactor (3) into AC power, and supplies the AC power to a synchronous machine (4); a gate pulse generation circuit (40) which generates a gate pulse to be provided to thyristors of the converter (1) and the inverter (2); a control unit (20) which sets a phase control angle of the gate pulse to be provided to the thyristors of the converter (1), by controlling a current of the converter (1) such that the DC current flowing into the DC reactor (3) matches a current command value; and an abnormality detection unit (50) which compares a detection value of the DC current with the current command value, and determines an abnormality in the gate pulse based on a comparison result.
Abstract:
Embodiments described herein provide a power delivery system, as well as a method of configuring the power delivery system. The power delivery system includes two or more rectifiers electrically coupled to an AC power source and configured to generate a direct current. The power delivery system also includes two or more inverters configured to receive the direct current and generate an alternating current waveform for powering a load. Moreover, the two or more rectifiers and the two or more inverters are coupled in series with each other through an inductor.
Abstract:
An apparatus includes a DC-link (26), a voltage converter (14), a bus voltage controller (36), and a supervisory controller (12). The voltage converter (14) is configured to convert a first DC voltage into a second DC voltage based on a command signal and based on an adjustment signal and to supply the second DC voltage to the DC-link (26). The bus voltage controller (36) is configured to iterate calculation of the adjustment signal to communicate each iterated calculation of the adjustment signal to the voltage converter (14). The supervisory controller (12) is configured to iterate calculation of the command signal and to communicate each iterated calculation of the command signal to the voltage converter (14) and to the bus voltage controller (36). A frequency of the bus voltage controller (36) to communicate each iterated calculation of the adjustment signal is higher than a frequency of the supervisory controller (12) to communicate each iterated calculation of the command signal.
Abstract:
A transverse flux machine (24) has at least three phases (60,61,62), each provided by a stator core (50,52) and phase windings (34). Each of the at least three phases is captured within a common housing (80,82). Parallel lines (23) extend from the at least three phases, and a current source converter is created on each of the parallel lines by inductors (26), a switching network (28,29), and communicating capacitors (32), which are received within the common housing (80,82).
Abstract:
A motor driving device includes a direct current (DC) link capacitor configured to store DC power, and an inverter configured to convert the DC power stored in the DC link capacitor into AC power and supply the AC power to a motor. The motor driving device includes a shunt resistor configured to sense current flowing through the inverter and detect whether the current has reached threshold current for controlling a regenerative voltage during a braking operation. A control unit is configured to control an operation of the inverter and perform a regenerative operation when the braking operation is started. The control unit, during the regenerative operation, switches motive power of a drum connected to the motor into regenerative energy and transmit the regenerative energy to the DC link capacitor, by controlling active component current and reactive component current together in response to the reaching of the threshold current.
Abstract:
A thyristor starting device includes: a converter which converts AC power supplied from an AC power source into DC power; a DC reactor which smooths a DC current; an inverter which converts the DC power provided from the converter into AC power, and supplies the AC power to a synchronous machine; a gate pulse generation circuit which generates a gate pulse to be provided to thyristors of the converter and the inverter; a control unit which sets a phase control angle of the gate pulse to be provided to the thyristors of the converter, by controlling a current of the converter such that the DC current flowing into the DC reactor matches a current command value; and an abnormality detection unit which compares a detection value of the DC current with the current command value, and determines an abnormality in the gate pulse based on a comparison result.
Abstract:
A load commutated inverter (LCI) drive system for a synchronous electrical machine is provided. The system may include a first supply bridge and a second supply bridge, each of which may include an alternating current to direct current (AC-to-DC) source side converter, a DC link circuit, and a DC-to-AC load side inverter. The system may include a controller for selectively controlling at least one of the first supply bridge and the second supply bridge by selective firings of SCRs. The electrical power outputted from the first supply bridge and the second supply bridge may be combined by an output delta-wye electric power transformer and supplied to the electrical machine. The LCI drive system may further include one or more input electric power transformers configured to supply an input electric power to the first supply bridge and the second supply bridge.
Abstract:
An apparatus includes a DC-link, a voltage converter, a bus voltage controller, and a supervisory controller. The voltage converter is configured to convert a first DC voltage into a second DC voltage based on a command signal and based on an adjustment signal and to supply the second DC voltage to the DC-link. The bus voltage controller is configured to iterate calculation of the adjustment signal to communicate each iterated calculation of the adjustment signal to the voltage converter. The supervisory controller is configured to iterate calculation of the command signal and to communicate each iterated calculation of the command signal to the voltage converter and to the bus voltage controller. A frequency of the bus voltage controller to communicate each iterated calculation of the adjustment signal is higher than a frequency of the supervisory controller to communicate each iterated calculation of the command signal.