Abstract: An apparatus comprises switches, a measurement unit, and a telemetry subsystem. The switches connect the current sources to a power bus when in a first position and to the measurement unit when the switches are in a second position. The measurement unit generates a ramp signal to control the solar strings from an open circuit state to a short circuit state linearly in a short duration and provides continuous current and voltage telemetry data at the output while the set of switches is in the second position. The telemetry subsystem is pre-set to a dwell mode and samples a large amount of voltage and current telemetry data. The telemetry subsystem transmits this data to ground directly to eliminate the need for processing and storage resources in the spacecraft. The telemetry data is used to plot I-V curve for health monitoring.

Abstract: A current controller for a spacecraft comprises ripple regulators and a pulse width modulated regulator. Ripple regulators receive current from associated current sources and pass current to or shunts current away from the bus. The pulse width modulated regulator receives current from another current source and passes a portion of the current to the bus. This regulator varies its set point to float between ripple regulators passing current and the ripple regulators shunting current and adjusts a portion of current that is shunted away from the bus. The current shunted by the regulators form a total shunt current. The variable set point of the pulse width modulated regulator varies as the total shunt current varies. The ripple regulator set points do not vary in this manner. An error generation circuit generates an error that adjusts the ripple regulator and the pulse width modulated regulator to a desired bus voltage level.

Abstract: An apparatus comprises switches, a measurement unit, and a telemetry subsystem. The switches connect the current sources to a power bus when in a first position and to the measurement unit when the switches are in a second position. The measurement unit generates a ramp signal to control the solar strings from an open circuit state to a short circuit state linearly in a short duration and provides continuous current and voltage telemetry data at the output while the set of switches is in the second position. The telemetry subsystem is pre-set to a dwell mode and samples a large amount of voltage and current telemetry data. The telemetry subsystem transmits this data to ground directly to eliminate the need for processing and storage resources in the spacecraft. The telemetry data is used to plot I-V curve for health monitoring.

Abstract: A current controller for a spacecraft comprises ripple regulators and a pulse width modulated regulator. Ripple regulators receive current from associated current sources and pass current to or shunts current away from the bus. The pulse width modulated regulator receives current from another current source and passes a portion of the current to the bus. This regulator varies its set point to float between ripple regulators passing current and the ripple regulators shunting current and adjusts a portion of current that is shunted away from the bus. The current shunted by the regulators form a total shunt current. The variable set point of the pulse width modulated regulator varies as the total shunt current varies. The ripple regulator set points do not vary in this manner. An error generation circuit generates an error that adjusts the ripple regulator and the pulse width modulated regulator to a desired bus voltage level.