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US 10,312,710 B1Granted
Energy recovery pulse forming network
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorChristopher Adrian Martino
Life of this patent
Estimating the term…
Abstract
An energy recovery pulse forming network and method that recovers at least a portion of the energy in a railgun by transferring energy dissipated from the railgun inductance back to an initial source of the energy, such as an input capacitor, for use by the network. This reduces the amount of energy required from an external power source to charge the input capacitor during subsequent railgun firings.
Claims16
An energy recovery pulse forming network comprising:
- an input capacitor, said input capacitor connectable to and chargeable by a power supply, said input capacitor for storing energy for transfer to a supply inductor;
- a first switch coupled in series with said input capacitor to form a first series combination;
- a first diode coupled in series with a third switch to form a second series combination;
- wherein said first series combination is coupled in parallel with said second series combination to form a first series-parallel combination;
- a ninth switch coupled in parallel with a load capacitor to form a first parallel combination;
- an eighth switch coupled in series with said first parallel combination to form a second series-parallel combination;
- a load coupled in parallel with said second series-parallel combination to form a third series-parallel combination;
- a second diode coupled in series with said third series-parallel combination to form a fourth series parallel combination;
- a seventh switch coupled in series to a recovery capacitor to form a third series combination;
- wherein said third series combination is coupled in parallel with said fourth series-parallel combination to form a fifth series-parallel combination;
- a fifth switch coupled in series with a fourth switch to form a fourth series combination;
- and,
- said supply inductor, a sixth switch, and a second switch connected in wye to form a first wye formation;
- wherein said first series-parallel combination, said fifth series-parallel combination, and said fourth series combination are connected in delta around said first wye formation to form a first delta formation;
- and
- further wherein a junction between said first series-parallel combination and said fifth series-parallel combination connects at a node for said second switch from said first wye formation, a junction between said fifth series-parallel combination and said fourth series combination connects at a node for said sixth switch from said first wye formation, and a junction between said fourth series combination and said first series-parallel combination connects at a node for said supply inductor from said first wye formation.
13 more elements
An energy recovery pulse forming network comprising:
- an input capacitor, said input capacitor connectable to and chargeable by said power supply, said input capacitor for storing energy for transfer to a supply inductor;
- a first switch coupled in series with said input capacitor and further coupled in series with said supply inductor;
- said supply inductor coupled in series with said first switch and further coupled in series with a sixth switch;
- said sixth switch coupled in series with said supply inductor and further coupled in series with a second diode;
- a second diode coupled in series with said sixth switch and further connectable to a load;
- said load coupled in series with said second diode and further coupled in series with said input capacitor;
- a third switch coupled in parallel with said input capacitor at a point between said load and said input capacitor and further coupled to a first diode;
- said first diode coupled in series with said third switch and at a point between said first switch and said supply inductor;
- a second switch coupled in parallel with said third switch at a point between said load and said third switch and further coupled at a point between said supply inductor and said sixth switch;
- a seventh switch coupled in parallel with said second switch at a point between said load and said second switch and further coupled in series to a recovery capacitor;
- said recovery capacitor coupled in series to said seventh switch and further coupled at a point between said sixth switch and said second diode;
- an eighth switch coupled in parallel with said seventh switch at a point between said load and said seventh switch and further coupled in series to a load capacitor and in series to a ninth switch;
- said load capacitor coupled in series with said eighth switch and further coupled at a point between said ninth switch and said load;
- said ninth switch coupled in series with said eighth switch and in parallel with said load capacitor at a point between said eighth switch and said load capacitor and further coupled at a point between said second diode and said load;
- a fifth switch coupled in series with said recovery capacitor at a point between said sixth switch and said second diode and further coupled to a fourth switch;
- and,
- said fourth switch coupled in series with said fifth switch and coupled in series to said first diode at a point between said first switch and said supply inductor,
- wherein said fifth switch and said fourth switch are in parallel with said supply inductor and said sixth switch.
15 more elements
A method for energy recovery in a pulse forming network comprising:
- obtaining a railgun including conductive rail(s) loaded with a conductive armature having a projectile, said railgun conductively coupled with an energy recovery pulse forming network for powering said railgun and launching said armature out a muzzle end of said railgun;
- charging an input capacitor of said energy recovery pulse forming network from a power supply;
- receiving an pulse initiation signal;
- initiating a first process, said first process powering said energy recovery pulse forming network with energy from said input capacitor, said energy recovery pulse forming network further powering said railgun and moving said armature down said rail(s) and out said muzzle end of said railgun, said first process comprising:
- determining a percentage close time of a first switch that permits buck charging and buck discharging of a supply inductor in said network, and
- when said percentage close time of said first switch is determined to be greater than 100%, closing said first switch and determining a percentage close time of a second switch that permits boost charging and boost discharging of said supply inductor,
- wherein said determining a percentage close time of a first switch comprises:
- calculating
- D
- buck
- =
- V
- out
- ,
- target
- +
- I
- out
-
- Z
- out
- V
- i
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-
- n
- -
- I
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-
-
- n
-
- Z
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-
-
- n
- ;
- wherein Dbuck is a percentage of time that said first switch should be closed during a next time step, Vout,target is an output voltage target value, Iout is a current provided by said network to inductor 126, Zout is an estimate of an output impedance of said network, Vin is an input voltage at said input capacitor, Iin is a current from said input capacitor into said first switch, and Zin is an estimate of an input impedance of said network;
- wherein, Zout and Zin are calculated by separate proportional-integral controllers that drive an error between a current through said supply inductor and a target module current to 0;
- and,
- wherein Vout,target is calculated by a proportional error and a ramp driven by an error between a desired current in said railgun and a target current in said railgun,
- and further wherein said determining a percentage close time of a second switch comprises:
- calculating
- D
- boost
- =
- (
- V
- out
- ,
- target
- +
- I
- out
-
- Z
- out
- )
- -
- (
- V
- i
-
-
- n
- -
- I
- i
-
-
- n
-
- Z
- i
-
-
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- V
- out
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- ;
- wherein Dboost is the percentage of time that said second switch should be closed during a next time step, Vout,target is an output voltage target value, Iout is a current provided by said network to inductor 126, Zout is an estimate of the output impedance of said network, Vin is an input voltage at said input capacitor, Iin is a current from said input capacitor into said first switch, and Zin is an estimate of an input impedance of said network;
- wherein Zout and Zin are calculated by separate proportional-integral controllers that drive the error between the current through said supply inductor and a target module current to 0;
- and
- wherein Vout,target is calculated by a proportional error and a ramp driven by an error between a desired current in said railgun and said target current in said railgun;
- and
- initiating a second process, said second process interrupting said first process on the occurrence of an interrupt event and transferring energy dissipated from a railgun inductance of said railgun back to said input capacitor.
94 more elements
Dependencies are inferred from the claim text.