Abstract: A method includes selecting a test waveform to inject from a first DC converter to at least one first DC power source other than a fuel cell, determining a first resulting ripple that will be generated in response to injecting the test waveform onto the battery, determining at least one offset waveform to inject from at least one second DC converter to at least one second DC power source to generate one or more second ripples which cancel the first resulting ripple, injecting the test waveform from the first DC converter to the at least one first DC power source, injecting the at least one offset waveform from the at least one second DC converter to the at least one second DC power source, and determining a characteristic of the first DC power source based at least in part on the impedance response of the first DC power source.

Abstract: Systems and methods are provided for creating and operating a Direct Current (DC) micro-grid. A DC micro-grid may include power generators, energy storage devices, and loads coupled to a common DC bus. Power electronics devices may couple the power generators, energy storage devices, and loads to the common DC bus and provide power transfer.

Abstract: A method includes selecting a test waveform to inject to a battery from a first DC converter, determining a first resulting ripple that will be generated in response to injecting the test waveform, determining at least one offset waveform to inject to at least one second DC power source from at least one second DC converter such that one or more second ripples will be provided that will cancel the first resulting ripple if the battery is charging, injecting the test waveform to the battery, injecting the at least one offset waveform to the at least one second DC power source, determining if the first resulting ripple has been cancelled, and determining if the battery is charging or discharging based on the step of determining if the first resulting ripple has been cancelled.

Abstract: A method includes selecting a test waveform to inject from a first DC converter to at least one first DC power source other than a fuel cell, determining a first resulting ripple that will be generated in response to injecting the test waveform onto the battery, determining at least one offset waveform to inject from at least one second DC converter to at least one second DC power source to generate one or more second ripples which cancel the first resulting ripple, injecting the test waveform from the first DC converter to the at least one first DC power source, injecting the at least one offset waveform from the at least one second DC converter to the at least one second DC power source, and determining a characteristic of the first DC power source based at least in part on the impedance response of the first DC power source.

Abstract: A method includes selecting a test waveform to inject to a battery from a first DC converter, determining a first resulting ripple that will be generated in response to injecting the test waveform, determining at least one offset waveform to inject to at least one second DC power source from at least one second DC converter such that one or more second ripples will be provided that will cancel the first resulting ripple if the battery is charging, injecting the test waveform to the battery, injecting the at least one offset waveform to the at least one second DC power source, determining if the first resulting ripple has been cancelled, and determining if the battery is charging or discharging based on the step of determining if the first resulting ripple has been cancelled.

Abstract: Systems, methods, and devices of the various embodiments enable electrochemical impedance spectroscopy (“EIS”) to be performed on electrochemical devices, such as fuel cell stack segments, by power electronics connecting the electrochemical devices in parallel to a common load and/or bus. In an embodiment, the power electronics may compensate for any ripple generated during EIS such that no ripple is realized at the common load and/or bus.

Abstract: Systems, methods, and devices of the various embodiments enable electrochemical impedance spectroscopy (“EIS”) to be performed on electrochemical devices, such as fuel cell stack segments, by power electronics connecting the electrochemical devices in parallel to a common load and/or bus. In an embodiment, the power electronics may compensate for any ripple generated during EIS such that no ripple is realized at the common load and/or bus.