Abstract: A removable electrical power cell including an incoming electrical source connector with a circuit interrupting device and an electrically isolated outgoing electrical load connector, an electro-mechanical switching assembly connected to a movable disconnect switch to move the disconnect switch between an open and grounded position and a closed and energized position and a controller to provide an input signal for controlling the operation of the electro-mechanical switching assembly to control an operation of the removable electrical power cell. The electro-mechanical switching assembly includes a rack and pinion switching assembly and a lockout limit switch to control operation of the automatic power switching assembly. The electro-mechanical switching assembly including a motor driven switching assembly to automatically open and close the high voltage power isolation switch based on an incoming signal.

Abstract: Methods, systems, apparatus and devices for an arc resistant electrical enclosure that includes a duct system of adjacent pressure relief chambers separated by flame arresting ventilation partitions to provide a torturous mechanical maze to relieve internal pressure and extinguish internal hot flames within the flame arresting duct system prior to exiting the enclosure expelling gasses into the external environment. The adjacent partitioned pressure relief chambers for routing pressure and or flames through the duct system with ninety degree turns from one pressure relief chamber into the next adjacent pressure relief chamber. In an embodiment, a set of ventilation panels is located within one or more of the adjacent pressure relief chambers and each next pressure relief chamber can have a volume that is less than the volume in the preceding chamber.

Abstract: As applications of variable frequency drives (VFD) (50) continue to grow so do challenges to provide VFD (50) systems meeting application specific requirements. For multiple reasons to include safety standards and electromagnetic interference, reduced ground leakage current is desirable. Building high output voltage VFDs (50) using transistors rated at voltages lower than the VFD output voltage is desireable for economic reasons. The apparatus and method described herein meet these challenges and others, in part by placing an electrically insulating plate (cp176) having high thermal conductivity, a low dielectric constant, and high dielectric strength between the heat sink plate of a VFD power semiconductor module and a grounded cooling plate (80 TE).

Abstract: A high-voltage sensing capacitor as an interface apparatus that may be used to attach an indicator unit to a high-voltage AC electrical bus and to provide safety to maintenance personnel. The high-impedance nature of the sensing capacitor effectively isolates the indicator unit from the high-voltage source to which it is connected. The sensing capacitor can be directly mounted between a high-voltage busbar and an indicator unit to provide visual and/or audible alerts to maintenance personnel when high voltage conditions are detected on the busbar. The sensing capacitor is comprised of a portable, unitary capacitive structure that includes a molded insulator body encapsulating two electrodes. The electrodes only partially or incompletely overlap within the insulator body. The electrode spacing and configuration is structured to provide a deliberate amount of coupling between the two electrodes in the presence of an AC electric field.

Abstract: A high-voltage sensing capacitor as an interface apparatus that may be used to attach an indicator unit to a high-voltage AC electrical bus and to provide safety to maintenance personnel. The high-impedance nature of the sensing capacitor effectively isolates the indicator unit from the high-voltage source to which it is connected. The sensing capacitor can be directly mounted between a high-voltage busbar and an indicator unit to provide visual and/or audible alerts to maintenance personnel when high voltage conditions are detected on the busbar. The sensing capacitor is comprised of a portable, unitary capacitive structure that includes a molded insulator body encapsulating two electrodes. The electrodes only partially or incompletely overlap within the insulator body. The electrode spacing and configuration is structured to provide a deliberate amount of coupling between the two electrodes in the presence of an AC electric field.

Abstract: A high-voltage sensing capacitor as an interface apparatus that may be used to attach an indicator unit to a high-voltage AC electrical bus and to provide safety to maintenance personnel. The high-impedance nature of the sensing capacitor effectively isolates the indicator unit from the high-voltage source to which it is connected. Multiple electrical phases can be interfaced using a plurality of such sensing capacitors. The sensing capacitor can be directly mounted to a high-voltage busbar. The indicator unit may provide visual and/or audible alerts to maintenance personnel when high voltage conditions are detected on the busbar by the sensing capacitor. The sensing capacitor is comprised of a portable, unitary capacitive structure that includes a molded insulator body encapsulating two electrodes. The electrodes of the capacitor only partially or incompletely overlap within the insulator body.

Abstract: Methods, systems, apparatus and devices for an arc resistant electrical enclosure that includes a duct system of adjacent pressure relief chambers separated by flame arresting ventilation partitions to provide a torturous mechanical maze to relieve internal pressure and extinguish internal hot flames within the flame arresting duct system prior to exiting the enclosure expelling gasses into the external environment. The adjacent partitioned pressure relief chambers for routing pressure and or flames through the duct system with ninety degree turns from one pressure relief chamber into the next adjacent pressure relief chamber. In an embodiment, a set of ventilation panels is located within one or more of the adjacent pressure relief chambers and each next pressure relief chamber can have a volume that is less than the volume in the preceding chamber.

Abstract: A high-voltage sensing capacitor as an interface apparatus that may be used to attach an indicator unit to a high-voltage AC electrical bus and to provide safety to maintenance personnel. The high-impedance nature of the sensing capacitor effectively isolates the indicator unit from the high-voltage source to which it is connected. Multiple electrical phases can be interfaced using a plurality of such sensing capacitors. The sensing capacitor can be directly mounted to a high-voltage busbar. The indicator unit may provide visual and/or audible alerts to maintenance personnel when high voltage conditions are detected on the busbar by the sensing capacitor. The sensing capacitor is comprised of a portable, unitary capacitive structure that includes a molded insulator body encapsulating two electrodes. The electrodes of the capacitor only partially or incompletely overlap within the insulator body.

Abstract: As applications of variable frequency drives (VFD) (50) continue to grow so do challenges to provide VFD (50) systems meeting application specific requirements. For multiple reasons to include safety standards and electromagnetic interference, reduced ground leakage current is desirable. Building high output voltage VFDs (50) using transistors rated at voltages lower than the VFD output voltage is desirable for economic reasons. The apparatus and method described herein meet these challenges and others, in part by placing an electrically insulating plate (cp176) having high thermal conductivity, a low dielectric constant, and high dielectric strength between the heat sink plate of a VFD power semiconductor module and a grounded cooling plate (80 TE).

Abstract: A fault handling system for short circuit recovery in three-phase multiple-level inverter bridges, used to drive inductive loads, which waits for either desaturation of switches or expiration of a delay period based upon an amount of time before saturated switches are damaged before commanding off switches that are saturated, and which artificially creates a dead-short across the three-phase output to force switches conducting a fault current to desaturate. By delaying the switching-off of the inverter bridge during a fault, waiting for desaturation to occur, the statistical likelihood of switch survival is improved.

Abstract: To protect people and equipment, three-phase AC drives need to be properly grounded, and ground faults need to be quickly detected. Conventional methods of detecting ground faults are affected by external factors that reduce their sensitivity. As an improvement on conventional methods, ground fault detection is accomplished by deriving a neutral point from the three-phase output of an AC drive, decoupling normal operating currents of the AC drive from the neutral point, resistively grounding the neutral point, and sensing when a magnitude of signals between the neutral point and ground exceed a maximum threshold level, ground faults are quickly detected. By effectively filtering normal operating currents from ground fault current, detection sensitivity is improved.

Abstract: An AC drive which can be applied to any power using device and in particular is a medium voltage AC drive. In a preferred embodiment, a multilevel AC drive topology is implemented, with the drive including a plurality of inverters and converter electrically coupled through electrical buses and physically coupled through their respective modular bases, and sharing a common cooling system connected to the respective heat exchangers of each component. The AC drive generally is made up of a plurality of inverter modules, which are connected to a converter module, and with each of the above components packaged in a relatively small unit having a cooling apparatus.

Abstract: An AC drive which can be applied to any power using device and in particular is a medium voltage AC drive. In a preferred embodiment, a multilevel AC drive topology is implemented, with the drive including a plurality of inverters and converter electrically coupled through electrical buses and physically coupled through their respective modular bases, and sharing a common cooling system connected to the respective heat exchangers of each component. The AC drive generally is made up of a plurality of inverter modules, which are connected to a converter module, and with each of the above components packaged in a relatively small unit having a cooling apparatus.

Abstract: To protect people and equipment, three-phase AC drives need to be properly grounded, and ground faults need to be quickly detected. Conventional methods of detecting ground faults are affected by external factors that reduce their sensitivity. As an improvement on conventional methods, ground fault detection is accomplished by deriving a neutral point from the three-phase output of an AC drive, decoupling normal operating currents of the AC drive from the neutral point, resistively grounding the neutral point, and sensing when a magnitude of signals between the neutral point and ground exceed a maximum threshold level, ground faults are quickly detected. By effectively filtering normal operating currents from ground fault current, detection sensitivity is improved.

Abstract: A ground fault relay, especially useful to detect motor leakage currents due to insulation failure. The invention operates in two (2) modes. The first mode is a “look-ahead” mode where possible motor circuit insulation failure is detected prior to the electrical motor being turned on, and the second mode is “real time” mode which detects leakage currents after the motor is turned on and during running of the motor. Processing circuitry is disclosed which enables a user to set predetermined values of leakage current to be detected and to trip the relay after comparison of the leakage current and the predetermined value, if the former is larger than the latter. This invention is able to accurately detect extremely small values of ground leakage current without experiencing nuisance tripping due to extraneous noise.