Micro-Electromechanical System Based Arc-Less Switching With Circuitry For Absorbing Electrical Energy During A Fault Condition

Abstract

A system is presented. The system includes a micro-electromechanical system switch. Further, the system includes a balanced diode bridge configured to suppress arc formation between contacts of the micro-electromechanical system switch. A pulse circuit is coupled to the balanced diode bridge to form a pulse signal in response to a fault condition. An energy-absorbing circuitry is coupled in a parallel circuit with the pulse circuit and is adapted to absorb electrical energy resulting from the fault condition without affecting a pulse signal formation by the pulse circuit.

Description

DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a block diagram of an exemplary MEMS based switching system, in accordance with aspects of the present technique;

FIG. 2 is schematic diagram illustrating the exemplary MEMS based switching system depicted in FIG. 1;

FIGS. 3-5 are schematic flow charts illustrating an example operation of the MEMS based switching system illustrated in FIG. 2;

FIG. 6 is schematic diagram illustrating a series-parallel array of MEMS switches;

FIG. 7 is schematic diagram illustrating a graded MEMS switch;

FIG. 8 is a flow diagram depicting an operational flow of a system having the MEMS based switching system illustrated in FIG. 1;

FIG. 9 is a graphical representation of experimental results representative of turn off of the switching system.

FIG. 10 is schematic diagram illustrating an exemplary MEMS-based switching system, in accordance with aspects of the present invention; and

FIGS. 11 and 12 respectively illustrate a graphical representation of simulation results of example circuit signals illustrative of operational details of the switching system of FIG. 10, in accordance with aspects of the present invention.

Claims

1. A system, comprising: a micro-electromechanical system switch;a balanced diode bridge configured to suppress arc formation between contacts of the micro-electromechanical system switch;a pulse circuit coupled to the balanced diode bridge, the pulse circuit comprising a pulse capacitor adapted to form a pulse signal for causing flow of a pulse current through the balanced diode bridge, the pulse signal being generated in response to a fault condition in a load circuit coupled to the micro-electromechanical system switch; andenergy-absorbing circuitry coupled in a parallel circuit with the pulse circuit, the circuitry comprising an energy-absorbing capacitor adapted to absorb electrical energy resulting from the fault condition without affecting a pulse signal formation by the pulse circuit, wherein the energy-absorbing capacitor is further adapted for restraining a rate-of-change of a voltage that develops across the diode bridge upon occurrence of the fault condition.

2. The system of claim 1 wherein a capacitance value of the pulse capacitor is selected to control one or more pulse signal characteristics of the pulse signal independent of a capacitance value of the energy-absorbing capacitor.

3. The system of claim 2 wherein the one or more pulse signal characteristics of the pulse signal are selected from the group consisting of a width of the pulse signal, a peak of the pulse signal, and a combination thereof.

4. The system of claim 1 wherein a capacitance value of the energy-absorbing capacitor is selected to control an amount of electrical energy absorbed by the energy-absorbing capacitor independent of a capacitance value of the pulse capacitor.

5. The system of claim 1 wherein the energy-absorbing circuitry further comprises a diode connected in a series circuit with the energy-absorbing capacitor, said diode being connected to be in a conductive state when the voltage that develops across the diode bridge reaches a value that matches a value of an initial voltage value stored in the energy absorbing capacitor, wherein the conductive state of said diode causes the energy-absorbing circuitry to receive fault current.

6. The system of claim 1, wherein the balanced diode bridge comprises a first branch and a second branch, and wherein the first branch comprises a first diode and a second diode coupled in a first series circuit and the second branch comprises a third diode and a fourth diode coupled in a second series circuit.

7. The system of claim 6, wherein the micro-electromechanical system switch is coupled in parallel across midpoints of the balanced diode bridge, and wherein a first midpoint is located between the first and second diodes and a second midpoint is located between the third and fourth diodes.

8. The system of claim 1, wherein the micro-electromechanical system switch is integrated with the balanced diode bridge in a single package.

9. The system of claim 1, wherein the pulse circuit is further configured to detect a fault condition and initiate opening of the micro-electromechanical system switch responsive to the fault condition.

10. The system of claim 1, further comprising a first plurality of micro-electromechanical switches electrically coupled in a series circuit.

11. The system of claim 10, wherein at least one of the first plurality of micro-electromechanical switches is further coupled in a parallel circuit comprising a second plurality of micro-electromechanical switches.

12. A system, comprising: switching circuitry comprising a micro-electromechanical system switch configured to switch the system from a first switching state to a second switching state;arc suppression circuitry coupled to the switching circuitry, wherein the arc suppression circuitry is configured to suppress an arc formation between contacts of the micro-electromechanical system switch;detection circuitry coupled to the arc suppression circuitry and configured to determine existence of a fault condition;a pulse circuit coupled to the arc suppression circuitry and the detection circuitry, wherein the pulse circuit is configured to form a pulse signal responsive to the fault condition, and wherein the pulse signal is applied to the arc suppression circuitry in connection with initiating an opening of the micro-electromechanical system switch; andan energy-absorbing circuitry coupled in a parallel circuit with the pulse circuit, the energy-absorbing circuitry adapted to absorb electrical energy resulting from the fault condition without affecting a pulse signal formation by the pulse circuit, wherein the energy-absorbing capacitor is further adapted for restraining a rate-of-change of a voltage that develops across the diode bridge upon occurrence of the fault condition.

13. The system of claim 12, wherein the arc suppression circuitry comprises a balanced diode bridge coupled in a parallel circuit with the micro-electromechanical system switch.

14. The system of claim 13, wherein the energy-absorbing circuitry comprises an energy-absorbing capacitor.

15. The system of claim 14, wherein the pulse circuit comprises a pulse capacitor that affects one or more characteristics of the pulse signal.

16. The system of claim 15 wherein a capacitance value of the energy-absorbing capacitor is selected to control an amount of electrical energy absorbed by the energy-absorbing capacitor independent of a capacitance value of the pulse capacitor.

17. The system of claim 16 wherein a capacitance value of the pulse capacitor is selected to control the one or more pulse signal characteristics of the pulse signal independent of the capacitance value of the energy-absorbing capacitor.

18. The system of claim 17 wherein the one or more pulse signal characteristics of the pulse signal are selected from the group consisting of a width of the pulse signal, a peak of the pulse signal, and a combination thereof.

19. The system of claim 14 wherein the energy-absorbing circuitry further comprises a diode connected in a series circuit with the energy-absorbing capacitor, said diode being connected to be in a conductive state when the voltage that develops across the diode bridge reaches a value that matches a value of an initial voltage value stored in the energy absorbing capacitor, wherein the conductive state of said diode causes the energy-absorbing circuitry to receive fault current.