Electrical control circuits for an energy converting apparatus

• US 8,559,197 B2
• Filed: 12/09/2009
• Issued: 10/15/2013
• Est. Priority Date: 10/13/2008
• Status: Active Grant

• Current Assignee: Qnergy Inc.
• Original Assignee: Infinia Corporation (Qnergy Ltd.)
• Inventors: Cullinane, Matthew John, Peterson, Allen, Fraser, Paul, Buchholz, Gregory Lyle, Wacknov, Joel Bradley
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Jackson, Lakaisha
• Application Number:
  US12/634,669
• Publication Number:
  US 20100182809A1
• Time in Patent Office: 1,406 Days
• Field of Search: 363/34, 363/37, 363/39
• US Class Current: 363/37
• CPC Class Codes: F04C 13/00 Adaptations of machines or pumps for special use, e.g. for extremely high pressures of pumps specially adapted for elastic fluids F04C25/00
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/02 Details of the control

Abstract

In one aspect the invention relates to an electrical circuit for use with a generator having an output port, the circuit to modify one of an electric current or voltage from the generator. The circuit includes a rectifier to convert the alternating current from the generator to direct current, the rectifier having a first port and a second port, the rectifier first port in communication with the output port of the generator; and a direct current to alternating current inverter to convert the direct current from the rectifier to alternating current, the inverter having a first port and a second port, the first port of the inverter in communication with the second port of the rectifier. In one embodiment, the generator is a linear alternator positioned within an energy converting apparatus comprising a Stirling engine having a piston such that motion of the piston drives the linear alternator.

Claims

1. An electrical circuit for use with a generator having an output port, the circuit to modify one of an electric current or voltage from the generator, the circuit comprising:

a rectifier to convert an alternating current from the generator to direct current, the rectifier having a first port and a second port, the rectifier first port in communication with the output port of the generator;

a direct current to alternating current inverter to convert the direct current from the rectifier to alternating current, the inverter having a first port and a second port, the first port of the inverter in communication with the second port of the rectifier, wherein the generator is a linear alternator positioned within an energy converting apparatus comprising a Stirling engine having a piston such that motion of the piston drives the linear alternator, and

a processor-based system for controlling the energy converting apparatus, the energy converting apparatus having a first subsystem having a cold side temperature and a second subsystem having a hot side temperature, an engine working fluid disposed within a chamber, wherein the piston moves relative to the working fluid, the processor-based system comprising;

an electronic memory device; and

an electronic processor in communication with the memory device and the energy converting apparatus, wherein the memory device comprises instructions that when executed by the processor cause the processor to;

store an empirically obtained dataset of energy converting apparatus operating parameters; and

determine an operating temperature ratio, wherein the operating temperature ratio is the ratio of the cold side temperature to the hot side temperature.

2. The electrical circuit of claim 1 further comprising a tuning capacitor positioned between the rectifier and the generator, the tuning capacitor having a first port and a second port, the first port in communication with the generator output port and the second port in communication with the first port of the rectifier.

3. The electrical circuit of claim 2 further comprising a stall circuit having a first port in communication with one of the first and second ports of the tuning capacitor.

4. The electrical circuit of claim 3 further comprising an auxiliary power supply having a first port in communication with the second port of the rectifier,

wherein the auxiliary power supply extracts energy from the output of the rectifier.

5. The electrical circuit of claim 4 wherein the auxiliary power supply is in electrical communication with an electrical energy storage device.

6. The electrical circuit of claim 4 wherein the second port of the inverter is in communication with an electrical grid and wherein the auxiliary power supply extracts energy from the grid using one of the first port of the inverter if the rectifier is not supplying energy to the output of the rectifier.

7. The electrical circuit of claim 1,

wherein the memory device comprises instructions that when executed by the processor cause the processor to:

monitor changes in a first derivative with respect to time of a temperature at a region of the energy converting apparatus; and

varying an operational state of a control system in response to a change in the first derivative with respect to time of the temperature.

8. The electrical circuit of claim 1 wherein the circuit further comprises a switch having a first port and a control port, the first port in communication with the second port of the inverter.

9. The electrical circuit of claim 8 further comprising a system controller having a first port, a second port, a third port and a fourth port, the first and second controller ports in communication with the first rectifier port and the third and fourth controller ports in communication with second port of the inverter,

wherein the switch comprises a third port in electrical communication with a power grid;

wherein the first controller port is a single phase voltage sense port,

wherein the second controller port is a single phase current sense port,

wherein the third controller port is a 3 phase voltage sense port and is in electrical communication with the switch, and

wherein the fourth controller port is a 3 phase current sense port and is in electrical communication with the third port of the switch.

10. The electrical circuit of claim 1 further comprising a system controller having a first port, a second port, a third port and a fourth port, the first and second controller ports in communication with the first rectifier port and the third and fourth controller ports in communication with second port of the inverter,

wherein the first controller port is a single phase voltage sense port,

wherein the second controller port is a single phase current sense port,

wherein the third controller port is a 3 phase voltage sense port, and

wherein the fourth controller port is a 3 phase current sense port.

11. The electrical circuit of claim 1, wherein the circuit comprises:

a tuning capacitor in electrical communication with the linear alternator; and

a stall circuit comprising an electrical load in electrical communication with the tuning capacitor such that the stall circuit in combination with the tuning capacitor has a predetermined resonant frequency and bandwidth such that when the stall circuit is connected to the linear alternator the Stirling engine enters a stall state, wherein the linear alternator has at least one operating frequency, the Stirling engine powered by incident solar energy.

12. The electrical circuit of claim 11 wherein the stall circuit is selected from the group of a resistor, a resistor and capacitor, a pair of capacitors, and a brake.

13. The electrical circuit of claim 11 wherein the bandwidth ranges from about 58 Hz to about 72 Hz and the predetermined resonant frequency is approximately 62 Hz.

14. The electrical circuit of claim 11 wherein the stall circuit comprises a resistor capacitor pair, the resistor capacitor pair when in communication with the tuning capacitor generates an impedance that when connected to the linear alternator stalls the linear alternator.

15. The electrical circuit of claim 11 wherein the stall circuit has an associated bandwidth sized to stall an energy converting apparatus component selected from the group consisting of an engine having at least one piston, a passive balancer, and the linear alternator.

16. The electrical circuit of claim 11 wherein the circuit is used with a passive balancer connected to a case which houses the Stirling engine and wherein a circuit component value of at least one circuit component in the stall circuit is selected in response to at least one resonance frequency associated with a moving mass component of the energy converting apparatus.

17. The electrical circuit of claim 1, wherein the energy converting apparatus comprises a motor controller for a positioning an object, the motor controller comprising:

a DC brushless motor having a Hall sensor, a Hall sensor port; and

a motor driver having a motor driver port;

a gear box in communication with the DC brushless motor and having a gear ratio greater than 200;

1; and

a position controller having an input port in communication with the Hall sensor and an output port in communication with the motor driver port,

wherein the Hall sensor provides information for commutation control to the motor driver and motion information to the position controller for position determination of the object.

20. The electrical circuit of claim 1 wherein the energy converting apparatus comprises a linear alternator and the piston amplitude is approximated by a control voltage associated with the linear alternator.

18. An electrical circuit for use with a generator having an output port, the circuit to modify one of an electric current or voltage from the generator, the circuit comprising:

a rectifier to convert an alternating current from the generator to direct current, the rectifier having a first port and a second port, the rectifier first port in communication with the output port of the generator;

a direct current to alternating current inverter to convert the direct current from the rectifier to alternating current, the inverter having a first port and a second port, the first port of the inverter in communication with the second port of the rectifier, wherein the generator is a linear alternator positioned within an energy converting apparatus comprising a Stirling engine having a piston such that motion of the piston drives the linear alternator;

a processor-based system for controlling the energy converting apparatus, the energy converting apparatus having a first subsystem having a cold side temperature and a second subsystem having a hot side temperature, an engine working fluid disposed within a chamber, wherein the piston moves relative to the working fluid, wherein the energy converting apparatus comprises a linear alternator and the piston amplitude is approximated by a control voltage associated with the linear alternator, the processor-based system comprising;

an electronic memory device; and

an electronic processor in communication with the memory device and the energy converting apparatus, wherein the memory device comprises instructions that when executed by the processor cause the processor to;

store an empirically obtained dataset of energy converting apparatus operating parameters; and

determine an operating temperature ratio, wherein the operating temperature ratio is the ratio of the cold side temperature to the hot side temperature.

19. The electrical circuit of claim 18 wherein the operating temperature ratio is determined by correlating electric power, charge pressure of engine working fluid, and piston amplitude using the dataset of energy converting apparatus operating parameters.

21. An electrical circuit for use with a generator having an output port, the circuit to modify one of an electric current or voltage from the generator, the circuit comprising:

a rectifier to convert an alternating current from the generator to direct current, the rectifier having a first port and a second port, the rectifier first port in communication with the output port of the generator;

a direct current to alternating current inverter to convert the direct current from the rectifier to alternating current, the inverter having a first port and a second port, the first port of the inverter in communication with the second port of the rectifier, wherein the generator is a linear alternator positioned within an energy converting apparatus comprising a Stirling engine having a piston such that motion of the piston drives the linear alternator;

a processor-based system for controlling the energy converting apparatus, the energy converting apparatus having a first subsystem having a cold side temperature and a second subsystem having a hot side temperature, an engine working fluid disposed within a chamber, and a piston which moves relative to the working fluid, the processor-based system comprising;

an electronic memory device; and

an electronic processor in communication with the memory device and the energy converting apparatus, wherein the memory device comprises instructions that when executed by the processor cause the processor to;

store an empirically obtained dataset of energy converting apparatus operating parameters; and

determine an operating temperature ratio, wherein the operating temperature ratio is the ratio of the cold side temperature to the hot side temperature,

wherein the operating temperature ratio is determined inferentially such that a direct temperature measurement is not used.