Abstract: A power system for connecting a power source, an energy storage unit and a grid includes a power inverter, an energy storage power converter and a controller. The power inverter is electrically coupled to the power source through a DC bus and converts DC power from the DC bus to AC power output to the grid. The power converter is electrically coupled between the DC bus and the energy storage unit and stores power in the energy storage unit and discharges power from the energy storage unit. The controller controls the power converter to store excess power from the power source that cannot be output to the grid in the energy storage unit, and control the energy storage power converter to discharge power stored in the energy storage unit to the power inverter to output to the grid.

Abstract: A DC/DC converter system includes a bidirectional DC/DC converter converting between voltage levels at first and second ports and a control system for controlling the DC/DC converter. The bidirectional DC/DC converter includes a first conversion stage connected to the first port and a second conversion stage interfaced with the first conversion stage and connected to the second port. The control system includes outer and inner control loops. The outer control loop compares a command for one of a voltage level, a current level or power at one of the first and second ports to an actual value of voltage level, current level or power level and outputs an interface current command based on the comparison. The inner control loop compares the interface current command to an actual interface current at an interface of the first and second conversion stages, and controls a switching signal duty value based on the comparison.

Abstract: A method for monitoring a potential hazard at an unoccupied transport unit and issuing a notification in response to detecting the potential hazard is provided. The method includes monitoring for the potential hazard at the unoccupied transport unit. The method also includes determining whether there is someone is in close proximity to the unoccupied transport unit upon determining the potential hazard. Also, the method includes providing a local notification of the potential hazard when it is determined that there is someone is in close proximity to the unoccupied transport unit and not providing the local notification of the potential hazard when it is determined that there is no one in close proximity to the unoccupied transport unit.

Abstract: A power system for connecting a power source, an energy storage unit and a grid includes a power inverter, an energy storage power converter and a controller. The power inverter is electrically coupled to the power source through a DC bus and converts DC power from the DC bus to AC power output to the grid. The power converter is electrically coupled between the DC bus and the energy storage unit and stores power in the energy storage unit and discharges power from the energy storage unit. The controller controls the power converter to store excess power from the power source that cannot be output to the grid in the energy storage unit, and control the energy storage power converter to discharge power stored in the energy storage unit to the power inverter to output to the grid.

Abstract: A power system for connecting a power source, an energy storage unit and a grid includes a power inverter, an energy storage power converter and a controller. The power inverter is electrically coupled to the power source through a DC bus and converts DC power from the DC bus to AC power output to the grid. The power converter is electrically coupled between the DC bus and the energy storage unit and stores power in the energy storage unit and discharges power from the energy storage unit. The controller controls the power converter to store excess power from the power source that cannot be output to the grid in the energy storage unit, and control the energy storage power converter to discharge power stored in the energy storage unit to the power inverter to output to the grid.

Abstract: A DC/DC converter system includes a bidirectional DC/DC converter converting between voltage levels at first and second ports and a control system for controlling the DC/DC converter. The bidirectional DC/DC converter includes a first conversion stage connected to the first port and a second conversion stage interfaced with the first conversion stage and connected to the second port. The control system includes outer arid inner control loops. The outer control loop compares a command for one of a voltage level, a current level or power at one of the first and second ports to an actual value of voltage level, current level or power level and outputs an interface current command based on the comparison. The inner control loop compares the interface current command to an actual interface current at an interface of the first and second conversion stages, and controls a switching signal duty value based on the comparison.

Abstract: A DC/DC converter system includes a bidirectional DC/DC converter converting between voltage levels at first and second ports and a control system for controlling the DC/DC converter. The bidirectional DC/DC converter includes a first conversion stage connected to the first port and a second conversion stage interfaced with the first conversion stage and connected to the second port. The control system includes outer and inner control loops. The outer control loop compares a command for one of a voltage level, a current level or power at one of the first and second ports to an actual value of voltage level, current level or power level and outputs an interface current command based on the comparison. The inner control loop compares the interface current command to an actual interface current at an interface of the first and second conversion stages, and controls a switching signal duty value based on the comparison.

Abstract: An energy storage system for direct DC coupling includes a power source electrically connected to a first node, a power converter coupled to the first node, an energy storage unit coupled to the first node through direct DC coupling, and a control system. The power converter controls the output voltage of the power source under the control of the control system. The energy storage unit draws energy from the power source or the bus when charging and supplies energy to the bus when discharging. A main switch is coupled between the first node and the energy storage unit. The control system is configure to control the power converter to adjust the output voltage to the energy storage unit voltage, control the main switch to electrically connect the energy storage unit to the first node, and control the main switch to electrically disconnect the energy storage unit from the first node.

Abstract: An energy storage system for direct DC coupling includes a power source electrically connected to a first node, a power converter coupled to the first node, an energy storage unit coupled to the first node through direct DC coupling, and a control system. The power converter controls the output voltage of the power source under the control of the control system. The energy storage unit draws energy from the power source or the bus when charging and supplies energy to the bus when discharging. A main switch is coupled between the first node and the energy storage unit. The control system is configure to control the power converter to adjust the output voltage to the energy storage unit voltage, control the main switch to electrically connect the energy storage unit to the first node, and control the main switch to electrically disconnect the energy storage unit from the first node.

Abstract: A power system for connecting a power source, an energy storage unit and a grid includes a power inverter, an energy storage power converter and a controller. The power inverter is electrically coupled to the power source through a DC bus and converts DC power from the DC bus to AC power output to the grid. The power converter is electrically coupled between the DC bus and the energy storage unit and stores power in the energy storage unit and discharges power from the energy storage unit. The controller controls the power converter to store excess power from the power source that cannot be output to the grid in the energy storage unit, and control the energy storage power converter to discharge power stored in the energy storage unit to the power inverter to output to the grid.

Abstract: A DC/DC converter system includes a bidirectional DC/DC converter converting between voltage levels at first and second ports and a control system for controlling the DC/DC converter. The bidirectional DC/DC converter includes a first conversion stage connected to the first port and a second conversion stage interfaced with the first conversion stage and connected to the second port. The control system includes outer and inner control loops. The outer control loop compares a command for one of a voltage level, a current level or power at one of the first and second ports to an actual value of voltage level, current level or power level and outputs an interface current command based on the comparison. The inner control loop compares the interface current command to an actual interface current at an interface of the first and second conversion stages, and controls a switching signal duty value based on the comparison.

Abstract: This patent document discloses power electronic transformers having a high-frequency link. An example apparatus include a transformer having a primary winding and a secondary winding, the transformer is configured to receive a primary power signal having a first frequency, a primary converter configured to selectively oscillate polarity of the primary windings with respect to the secondary windings at a second frequency, the second frequency substantially substantially higher than the first frequency, a secondary converter coupled to the secondary winding, the secondary converter configured to provide a load power signal using a high frequency power signal generated using the secondary winding. The secondary converter can be configured to reduce current flow in the primary winding when the polarity of the primary winding is switched, the reduced current follow is configured to reduce disturbances resulting from leakage inductance of the transformer.

Abstract: This patent document discloses power electronic transformers having a high-frequency link. An example apparatus include a transformer having a primary winding and a secondary winding, the transformer is configured to receive a primary power signal having a first frequency, a primary converter configured to selectively oscillate polarity of the primary windings with respect to the secondary windings at a second frequency, the second frequency substantially substantially higher than the first frequency, a secondary converter coupled to the secondary winding, the secondary converter configured to provide a load power signal using a high frequency power signal generated using the secondary winding. The secondary converter can be configured to reduce current flow in the primary winding when the polarity of the primary winding is switched, the reduced current follow is configured to reduce disturbances resulting from leakage inductance of the transformer.