Abstract: Power converters, protection systems and methods to protect a precharge circuit in which a precharge resistor voltage is indirectly monitored during a normal operating mode, and a rectifier and an inverter are selectively disabled in response to the indirectly measured precharge resistor voltage indicating a fault in a precharge circuit SCR.

Abstract: Power converters, protection systems and methods to protect a precharge circuit in which a precharge resistor voltage is indirectly monitored during a normal operating mode, and a rectifier and an inverter are selectively disabled in response to the indirectly measured precharge resistor voltage indicating a fault in a precharge circuit SCR.

Abstract: Disclosed examples include power conversion systems, computer readable mediums and methods for mitigating input filter resonance, in which a controller operates an active front end (AFE) rectifier in a first mode to turn a single rectifier switching device on and off and measures a filter voltage or current signal while all of the rectifier switches are off. The controller determines a resonant frequency based on a transient response of the measured voltage or current signal, and selectively adjusts a rectifier control parameter to mitigate filter resonance based on the resonant frequency.

Abstract: Disclosed examples include power conversion systems, computer readable mediums and methods for mitigating input filter resonance, in which a controller operates an active front end (AFE) rectifier in a first mode to turn a single rectifier switching device on and off and measures a filter voltage or current signal while all of the rectifier switches are off. The controller determines a resonant frequency based on a transient response of the measured voltage or current signal, and selectively adjusts a rectifier control parameter to mitigate filter resonance based on the resonant frequency.

Abstract: Control apparatus, techniques and computer readable mediums are presented to mitigate LCL filter resonance issue for voltage source converters. Two level voltage source converter with and without passive damping of LCL filter are selected for the comparative study. Control algorithms are presented to estimate the source impedance based on variable carrier PWM. Estimated source impedance is used to tune the control of the VSC to avoid the resonance of LCL filter has been presented. In situations in which LCL resonance cannot be avoided by tuning the control parameters, energy efficient techniques are disclosed to provide selective passive damping to facilitate continued power conversion system operation without significant adverse impact on system performance.

Abstract: Power conversion systems, filter circuits and integrated filter resistor and inductor apparatus are presented, in which a damping resistor is integrated with a filter inductor by winding joined resistor winding portions proximate to one another at least partially around a filter inductor core leg to form an integrated filter resistor and inductor apparatus for interconnection with filter capacitors to provide an input filter or an output filter for a motor drive or other power conversion system.

Abstract: Precharging systems and methods are presented for precharging a DC bus circuit in a power conversion system, in which precharging current is connected through a precharging resistance coupled between only a single AC input line and the DC bus circuit when the DC bus voltage is less than a non-zero threshold, and a controller individually activates controllable rectifier switching devices when the DC bus voltages greater than or equal to the threshold using DC gating or pulse width modulation to selectively provide a bypass path around the precharging resistance for normal load currents in the power conversion system.

Abstract: Power conversion systems, filter circuits and integrated filter resistor and inductor apparatus are presented, in which a damping resistor is integrated with a filter inductor by winding joined resistor winding portions proximate to one another at least partially around a filter inductor core leg to form an integrated filter resistor and inductor apparatus for interconnection with filter capacitors to provide an input filter or an output filter for a motor drive or other power conversion system.

Abstract: Precharging systems and methods are presented for precharging a DC bus circuit in a power conversion system, in which precharging current is connected through a precharging resistance coupled between only a single AC input line and the DC bus circuit when the DC bus voltage is less than a non-zero threshold, and a controller individually activates controllable rectifier switching devices when the DC bus voltages greater than or equal to the threshold using DC gating or pulse width modulation to selectively provide a bypass path around the precharging resistance for normal load currents in the power conversion system.

Abstract: Control apparatus, techniques and computer readable mediums are presented to mitigate LCL filter resonance issue for voltage source converters. Two level voltage source converter with and without passive damping of LCL filter are selected for the comparative study. Control algorithms are presented to estimate the source impedance based on variable carrier PWM. Estimated source impedance is used to tune the control of the VSC to avoid the resonance of LCL filter has been presented. In situations in which LCL resonance cannot be avoided by tuning the control parameters, energy efficient techniques are disclosed to provide selective passive damping to facilitate continued power conversion system operation without significant adverse impact on system performance.

Abstract: The invention relates to the handling of radioactive material. For instance, a radiation shield of the invention may include a body having a cavity therein for receiving radioactive material. An opening to the cavity may be defined in the body. A base may be releasably attachable to the body (generally toward the opening) to at least partially enclose the radioactive material in the cavity. In the case that the radiation shield includes a plurality of interchangeable bases, one of the bases may have at least one of a shorter length and a lighter weight than another of the bases. The base(s) may be designed to enclose more than one size and/or shape of container in the cavity. The base(s) may include a hand grip to facilitate manual gripping of the radiation shield. The base(s) may include a guard to reduce exposure to radiation from manual handling of the radiation shield.

Abstract: The invention relates to the handling of radioactive material. For instance, a radiation shield of the invention may include a body having a cavity therein for receiving radioactive material. An opening to the cavity may be defined in the body. A base may be releasably attachable to the body (generally toward the opening) to at least partially enclose the radioactive material in the cavity. In the case that the radiation shield includes a plurality of interchangeable bases, one of the bases may have at least one of a shorter length and a lighter weight than another of the bases. The base(s) may be designed to enclose more than one size and/or shape of container in the cavity. The base(s) may include a hand grip to facilitate manual gripping of the radiation shield. The base(s) may include a guard to reduce exposure to radiation from manual handling of the radiation shield.