Abstract: An electrical substation that transforms AC voltage to DC voltage is configurable between a current-source mode for charging batteries of a stationary work machine and a voltage-source mode for powering motors of a moving work machine. The substation receives medium-voltage AC power from a grid and includes a pair of DC power converters each formed from three-phase transformers and a single stage of silicon-controlled rectifier units. Adjustable connectors enable combining the power converters in parallel or keeping them separate to operate in the current-source mode for charging the machine batteries with up to 4800 ADC at 6 MW or for providing up to 1500 VDC in powering voltage. The connectors further enable combining the power converters in series to operate in the voltage-source mode for powering the machine motors with up to 3000 VDC at 6 MW.

Abstract: An electric motor is driven by modulating an inverter that supplies energy to the motor. Clamp modulation is used to produce an output line-to-line voltage, which enable the generation of direct current (DC) or low-frequency alternating current (AC) currents. The clamp modulation generates different combinations of switch states that result in zero output line-to-line voltage, which distributes losses between the switches and diodes differently. The distribution lowers the junction temperatures of the switches and diodes, thereby increasing the inverter's reliability and efficiency. The method can be implemented using either a carrier-based approach, which injects a common mode signal into the modulation signal, or a direct switch state vector-based approach, which uses various combinations of switch states in terms of order and time duration.

Abstract: An energy transfer system, including a configurable energy transfer interface, a plurality of sets of inverters, and a three-winding transformer, is disclosed. The configurable energy transfer interface includes a plurality of switches coupled DC voltage outputs of the plurality of sets of inverters. The plurality of switches is capable of connecting the DC voltage outputs of the plurality of sets of inverters to provide a first DC output voltage and a second DC output voltage for charging batteries of a work machine. The plurality of switches is also capable of connecting the DC voltage outputs of the plurality of sets of inverters in series to provide to provide high DC voltage output for operating the work machine.

Abstract: A vessel power system configured for a marine vessel includes a rectifier configured to receive an AC power input from a shore power source and provide a DC charging output to charge a battery and an active phase circuit configured to provide a regulated AC output to power onboard AC loads on the marine vessel. The active phase circuit is connected to the output of the rectifier and includes a return connection configured to form a return path for electric current from the onboard AC loads and configured such that the rectifier and the active phase circuit are configured to split the AC power input from the shore power source into the DC charging output to charge the battery and the regulated AC output to power the onboard AC loads.

Abstract: An electrical substation that transforms AC voltage to DC voltage is configurable between a current-source mode for charging batteries of a stationary work machine and a voltage-source mode for powering motors of a moving work machine. The substation receives medium-voltage AC power from a grid and includes a pair of DC power converters each formed from three-phase transformers and a single stage of silicon-controlled rectifier units. Adjustable connectors enable combining the power converters in parallel or keeping them separate to operate in the current-source mode for charging the machine batteries with up to 4800ADC at 6 MW or for providing up to 1500VDC in powering voltage. The connectors further enable combining the power converters in series to operate in the voltage-source mode for powering the machine motors with up to 3000VDC at 6 MW.

Abstract: A system has a DC bus circuit with first and second terminals, an intermediate node, first and second capacitors, first and second depletion mode FETs, and first and second switching control circuits, where the first depletion mode FET has a drain coupled to the first bus terminal, a source, and a gate coupled to the intermediate node, the second depletion mode FET has a drain coupled to the intermediate node, a source, and a gate coupled to the second bus terminal, the first switching control circuit turns the first depletion mode FET off responsive to a first capacitor voltage of the first bus capacitor being less than or equal to a second capacitor voltage of the second bus capacitor, and the second switching control circuit turns the second depletion mode FET off responsive to the first capacitor voltage being greater than or equal to the second capacitor voltage.

Abstract: Thermal monitoring and analysis of conditions in a power electronic system include sensing of thermal parameters of interest, such as temperature and humidity in an enclosure housing power electronic components. The components are cooled by a liquid coolant flow from a chiller through chiller plates associated with the power electronic components. Air is circulated through the enclosure for heat rejection from the chiller plates. Based on the sensed parameters, factors such as relative humidity and dew point of the cooling air may be computed and evaluated to determine the potential for condensation. Alarms, notices, or recommendations may be output for regulation of the chiller to avoid condensation. The system may also provide for evaluation of installation errors, and degradation of performance over time.

Abstract: A system has a DC bus circuit with first and second terminals, an intermediate node, first and second capacitors, first and second depletion mode FETs, and first and second switching control circuits, where the first depletion mode FET has a drain coupled to the first bus terminal, a source, and a gate coupled to the intermediate node, the second depletion mode FET has a drain coupled to the intermediate node, a source, and a gate coupled to the second bus terminal, the first switching control circuit turns the first depletion mode FET off responsive to a first capacitor voltage of the first bus capacitor being less than or equal to a second capacitor voltage of the second bus capacitor, and the second switching control circuit turns the second depletion mode FET off responsive to the first capacitor voltage being greater than or equal to the second capacitor voltage.

Abstract: Thermal monitoring and analysis of conditions in a power electronic system include sensing of thermal parameters of interest, such as temperature and humidity in an enclosure housing power electronic components. The components are cooled by a liquid coolant flow from a chiller through chiller plates associated with the power electronic components. Air is circulated through the enclosure for heat rejection from the chiller plates. Based on the sensed parameters, factors such as relative humidity and dew point of the cooling air may be computed and evaluated to determine the potential for condensation. Alarms, notices, or recommendations may be output for regulation of the chiller to avoid condensation. The system may also provide for evaluation of installation errors, and degradation of performance over time.