Space Systems/loral, LLC

Michael J McVey

Steven M Canzano

Stephen J Lenhart

Aaron J Mendelsohn

Howard E Pollard

Christopher F Hoeber

Bradley J Suppanz

Robert E Neff

Howard Webber

A magnetic assembly is constructed comprising a first core portion, a second core portion, and a winding assembly. The first and second core portions each include a base portion and a plurality of projections extending from the base portion. The winding includes a plurality of stacked layers having conductive paths applied to their surfaces. The winding is constructed with a bore, wherein each conductive path encircles the bore. A number of the stacked conductive layers form a primary winding, and a number of the stacked conductive layers form a secondary winding. The winding is disposed over the first core portion in a manner so that a projection engages the opening of the winding to provide magnetic coupling of winding and core. The second core portion is disposed over the first core portion to form a closed magnetic circuit through and around the winding.

Planar magnetic assembly

Improved solar cell circuit layouts and cell structures that protect solar arrays located on spacecraft disposed in geosynchronous earth orbit from electrostatic discharge. An insulating material, such as RTV adhesive, for example, is used as a barrier that disposed in intercell gaps between solar cells. The use of the insulating material modifies sparking in the gaps caused by electrostatic discharge so that, while the spark still occurs, it has different non-destructive characteristics. The use of the insulating material causes no damage to other solar cell materials, such as a Kapton insulating layer or substrate used to support the solar cells. Furthermore, unique solar cell wiring schemes are provided that limit the voltage between adjacent solar cells to 50 volts or less.

Solar array augmented electrostatic discharge for spacecraft in geosynchronous earth orbit

A battery cell bypass module comprises a sensor for detecting an operating condition of a battery cell such as voltage or temperature and a controller connected across the battery cell of a lithium ion battery, for example, and having a conductive mode and a normally non conductive mode. The controller is operable to change to the conductive mode when an operating condition of the battery cell exceeds a predetermined value to thereby shunt current around the battery cell. The sensor may be a temperature transducer such as a thermistor for measuring battery cell temperature and a cell temperature comparator such as an operational amplifier is operable to generate a temperature excessive signal when the signal from the temperature transducer exceeds a predetermined value, the controller then being operable to change to the conductive mode and thereby shunt current around the battery cell. The sensor may also be a voltage comparator, also an operational amplifier, for measuring voltage across the cell, the controller being operable in response to a voltage excessive signal to change the controller to the conductive mode and thereby shunt current around the battery cell. The controller includes a voltage limiting operational amplifier operable for transmitting a voltage excessive output signal when the input thereto exceeds a predetermined value and a transistor having a predetermined gate voltage allowing bypass current flow, the transistor being responsive to the voltage excessive output signal from the voltage limiting operational amplifier to shunt current around the battery cell.

Battery cell bypass module

A system for managing the operation of a battery such as a lithium ion battery having a plurality of serially connected individual cells comprises a bypass module electrically in parallel with each individual cell or, alternatively, with at least one of the cells or alternatively again with an individual cell and its associated grouping of one or more parallel cells. The module includes a sensor for detecting an operating condition of its associated cell and a charger operable for charging the cell. A charge controller is electrically connected with each bypass module and is operable in response to an operating condition of a cell detected by the sensor which is outside a predetermined range of magnitudes to change the bypass module to the conductive mode and thereby shunt current around the battery cell, while leaving unaffected each of the remaining cells. The charge controller includes a processor with mode selecting means for initiating operation of the charger for charging each of the plurality of cells, and a capability for establishing voltage and current set points for each of the bypass modules to thereby prevent overcharging of each associated cell. The processor is also operable for performing a multi step charge profile for each of the bypass modules such that when a predetermined voltage is achieved at the conclusion of a step, a subsequent step is performed at a reduced charge current until a final predetermined voltage is achieved at a charge current which has been reduced to zero.

Battery charge management architecture

There is provided a power system for a spacecraft that includes a plurality of electrical loads. The power system comprises N segmented solar array panels. Each of the N segmented solar array panels comprises Y solar array segments. The power system also comprises a plurality of power source blocks, each of which includes a respective one of the Y solar array segments of a respective one of the N segmented solar array panels. The Y solar array segments receive solar energy and provide electrical energy as outputs of respective ones of the power source blocks. The power system further comprises at least one switch which is controllable for coupling electrical energy output by individual ones of the power source blocks to selected individual ones of the electrical loads.

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Palo Alto, CA, United States of America

Michael J McVey