Method and system for charging and discharging high-voltage energy storage devices
AssigneePolarity, Inc.
InventorsDaniel Goluszek, Lawrence W. Goins
Life of this patent
Estimating the term…
Abstract
An energy storage device includes buck and boost switches that charge and discharge a charge storage element (e.g. a supercapacitor or ultracapacitor) over a broad voltage range. Integrated charge limiting prevents the storage element from sinking a potentially damaging level of current. Pulse-width modulated control signals are combined with higher-frequency signals to allow the resulting modulated control signals to pass through relatively small, inexpensive isolation transformers. Pairs of control signals may be combined to produce composite control signals that turn power switches on and off, or may be used to separately turn the power switches on and off.
Claims24
A power supply to deliver a voltage across first and second supply terminals, the power supply comprising:
- a charge-storage device having first and second charge-storage terminals;
- an inductor having first and second inductor terminals;
- a buck switch having a first current-handling terminal coupled to the first charge-storage terminal, a second current-handling terminal coupled to the first inductor terminal, and a buck-switch control port;
- a boost switch having a third current-handling terminal coupled to the first inductor terminal, a fourth current-handling terminal coupled to the second charge-storage terminal and the second supply terminal, and a boost-switch control port;
- and
- a recharge-limit switch having a fifth current-handling terminal coupled to the second inductor terminal, a sixth current-handling terminal coupled to the first supply terminal, and a recharge-limit control port.
A switch for selectively passing a current between first and second switch terminals having a voltage between them, the switch comprising:
- a controller to deliver a plurality of control signals, wherein each control signal is modulated to include alternate periods of a relatively high frequency and a relatively low frequency;
- and
- a switching element coupled between the first and second switch terminals and including:
- a first transformer to receive a first of the control signals, the first transformer to pass the relatively high frequency periods of the first control signal and to block the relatively low frequency periods of the first control signal;
- a first rectifier coupled to the transformer to receive and rectify the relatively high frequency periods passed by the transformer to form a first pulse-width-modulated switch-control signal;
- a second transformer to receive a second one of the control signals, the second transformer to pass the relatively high frequency periods of the second control signal and to block the relatively low frequency periods of the second control signal;
- a second rectifier coupled to the second transformer to receive and rectify the relatively high frequency periods passed by the second transformer to form a second pulse-width-modulated switch-control signal;
- and
- a power transistor having a control terminal and first and second current-handling terminals, wherein the control terminal is coupled to the first and second rectifiers to receive the first and second pulse-width modulated switch-control signals and the first and second current-handling terminals are coupled to the first and second switch terminals, respectively.
A method of modulating current flow through a plurality of switching elements connected in series between switch terminals, the method comprising:
- delivering a plurality of control signals, each control signal modulated to include alternate periods of a relatively high frequency and a relatively low frequency;
- rectifying each of the control signals to provide a plurality of rectified signals, each rectified signal exhibiting a first voltage during the periods of the relatively high frequency and a second voltage during the periods of the relatively low frequency;
- and
- turning each of the switching elements on and off using a first and a second of the rectified signals.
A high-power switch for selectively passing a current between first and second switch terminals, the switch comprising:
- control circuitry including:
- a control node to provide a pulse-width modulated control signal;
- a diode having a first diode terminal connected to the control node and a second diode terminal, the diode to selectively pass the control signal to the second diode terminal;
- a control transistor having a first control terminal connected to the control node to receive the control signal, a first current-handling terminal connected to the second diode terminal, and a second current-handling terminal;
- and
- a power transistor having a second control terminal coupled to the first current-handling terminal and the second diode terminal, a third current-handling terminal coupled to the first switch terminal, and a fourth current-handling terminal coupled to the second current-handling terminal and the second switch terminal.
Dependencies are inferred from the claim text.