Grid Synchronisation

• US 20130134790A1
• Filed: 10/19/2012
• Published: 05/30/2013
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Enecsys Limited
• Inventors: Amaratunga, Gehan Anil Joseph, Viraj, Andrabadu, Chisenga, Lesley
• Granted Patent: US 9,997,923 B2
• Time in Patent Office: Days
• US Class Current: 307/87
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/388 Islanding, i.e. disconnection of local power supply from the network
• CPC Class Codes: H02J 3/40 Synchronising a generator for connection to a network or to another generator
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 3/48 Controlling the sharing of the in-phase component
• CPC Class Codes: H02J 3/50 Controlling the sharing of the out-of-phase component
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

The invention relates to a grid synchroniser for connecting an AC output of a power converter to the AC grid mains. In one aspect the invention provides a grid synchroniser comprising an inverter controller to control an AC output of the inverter, the controller including a receiver to receive grid data from a grid sensor location remote from said inverter. In another aspect we describe techniques for rapid removal of charge from a control terminal of a power switching device such as a MOSFET, IGBT or Thyristor using a particular driver circuit.

Claims

1. A grid synchroniser to synchronise an AC output of an inverter to an AC grid mains, said inverter having a power input and an AC output for connection to said AC grid mains to provide a power supply input into said AC grid mains, the grid synchroniser comprising:

an inverter controller to control said AC output of said inverter, said controller including a receiver to receive grid data from a grid sensor location remote from said inverter, said grid sensor sensing a grid characteristic of said AC grid mains,

wherein said grid data comprises data relating to a grid characteristic of said AC grid mans sensed by a grid sensor, and wherein said inverter controller controls said AC output responsive to said grid data relating to said grid characteristic.

2. The grid synchroniser according to claim 1, wherein said sensed grid characteristic comprises a phase of said AC grid mains.

3. The grid synchroniser according to claim 1, wherein said receiver is in wired communication with a grid sensor.

4. The grid synchroniser according to claim 3, wherein said wired communication is through a power supply line.

5. The grid synchroniser according to claim 1, wherein said receiver is in wireless communication with a grid sensor.

6. The grid synchroniser according to claim 1, further comprising:

an inverter sensor to sense an inverter characteristic of said AC output of said inverter and to transmit inverter data relating to said sensed inverter characteristic to a grid sensor located remote from said inverter.

7. The grid synchroniser according to claim 6, wherein said sensed inverter characteristic comprises one or more of a phase of said AC output of said inverter, a power output or a power efficiency of said inverter.

8-11. -11. (canceled)

12. A system for micropower generation, the system comprising:

an inverter having a power input and an AC output for connection to an AC grid mains to provide a power supply input into said AC grid mains;

a sensor, remote from said inverter, to sense a grid characteristic of said AC grid mains and to transmit data relating to said sensed grid characteristic to said inverter,

wherein said inverter includes a receiver to receive said transmitted data, said inverter being configured to control said AC output responsive to said data relating to said sensed grid characteristic.

13. The system according to claim 12, wherein said sensed grid characteristic comprises a phase of said AC grid mains.

14. The system according to claim 12, wherein said sensor is configured to couple to said AC grid mains at a point where said AC output from said inverter is injected into said AC grid mains.

15. The system according to claim 14, comprising a plurality of said inverters each inputting power into said AC grid mains at substantially the same point.

16. The system according to claim 12, further comprising:

an inverter sensor to sense an inverter characteristic of said AC output of said inverter and to transmit inverter data relating to said sensed inverter characteristic to a grid sensor located remote from said inverter.

17. The system according to claim 16, wherein said sensed inverter characteristic comprises one or more of a phase of said AC output of said inverter, a power output or a power efficiency of said inverter.

18. A driver circuit for switching on and off a semiconductor switching device connected to an alternating current (ac) power supply, said semiconductor switching device having first and second terminals, and a switching control terminal to control switching between said first and second terminals, the driver circuit being configured to derive from said ac power supply a control signal for application to said switching control terminal of said semiconductor switching device to control said switching, said driver circuit comprising:

an input to receive a voltage derived from said ac power supply;

a reference line for coupling to one of said first and second terminals of said semiconductor switching device;

a rectifier having an input coupled to said input and an output; and

a resistive element coupled between said output of said rectifier and said reference line; and

a drive output for driving said switching control terminal of said semiconductor switching device, said drive output being coupled to a circuit node between said resistive element and said output of said rectifier.

19. The driver circuit as claimed in claim 18 further comprising a voltage limiting element coupled between said circuit node and said reference line.

20. The driver circuit as claimed in claim 18 further comprising a potential divider coupled to said input, and wherein said rectifier is coupled to an output of said potential divider.

21. The driver circuit as claimed in claim 20 wherein said resistive element has a resistance value of less than one fifth a resistance value of an arm of said potential divider.

22. The driver circuit as claimed in claim 20 wherein said resistive element has a resistance value of less than one tenth a resistance value of an arm of said potential divider.\

23. The driver circuit as claimed in claim 18 wherein said semiconductor switching device comprises a MOSFET, IGBT or Thyristor.

24. The driver circuit as claimed in claim 18 wherein said ac power supply comprises a grid mains power supply, and wherein said semiconductor switching device comprises a power semiconductor switching device with a breakdown voltage of at least 100 volts.

25-31. -31. (canceled)