COMBINED ELECTRICAL POWER PLANT

• US 20160094035A1
• Filed: 09/26/2014
• Published: 03/31/2016
• Est. Priority Date: 09/26/2014
• Status: Active Grant

• Current Assignee: Enrichment Technology Company Limited
• Original Assignee: Enrichment Technology Company Limited
• Inventors: Vor Dem Esche, Rainer, Treppmann, Christoph, Engelmann, Thilo
• Granted Patent: US 9,985,437 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 13/00007 using the power network as support for the transmission
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00024 by means of mobile telephony
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 3/30 using dynamo-electric machines coupled to flywheels
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids
• CPC Class Codes: Y04S 10/14 Energy storage units
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission
• CPC Class Codes: Y04S 40/124 using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 40/126 using wireless data transmission

Abstract

A combined electrical power plant is provided to supply power to a grid and a method to operate such a combined electrical power plant comprising a thermal power generation facility and an energy storage facility with a suitable energy storage capacity being able to supply additional electrical power to the grid and to receive and store electrical power from the thermal power generation facility or from the grid. Both facilities are electrically coupled to providing a combined power output to the grid and further comprise a plant controller to process the demand signal and to generate at least a first control signal and a second control signal from the demand signal, where the first control signal is a smoothened function of time of the demand signal resulting from a smoothening process executed by the plant controller taking into account operational characteristics of the thermal power generation facility.

Claims

1. A combined electrical power plant connected to an electrical grid to supply electrical power to the grid comprising a thermal power generation facility having a response time to supply a demanded amount of electrical power to the grid, which is limited by a thermal process, an energy storage facility with a suitable energy storage capacity being able to supply additional electrical power to the grid and to receive and store electrical power from the thermal power generation facility or from the grid, both facilities are electrically coupled to provide a combined power output to the grid according to a demand signal specifying the demanded amount of power as a function of time between a first and a second point of time to be supplied to the grid, and a plant controller to process the demand signal and to generate at least a first control signal and a second control signal from the demand signal, where the first control signal is a smoothened function of time of the demand signal resulting from a smoothening process executed by the plant controller taking into account operational characteristics of the thermal power generation facility to operate the thermal power generation facility under improved conditions, and to transmit the first control signal to the thermal power generation facility to supply power to the grid in accordance with the first control signal, and to transmit the second control signal to the energy storage facility to supply or to receive power in accordance to the second control signal being adapted to provide the combined power output in accordance to the demand signal, where the capacity of the energy storage facility is adapted to nominal power and ramp rate characteristics of the thermal power generation facility in order to at least minimize differences between demand signal and the provided combined power output at any point in time between the first and second points of time.

2. The combined electrical power plant according to claim 1, wherein the smoothening process applies a filter algorithm using at least one element of the group of band-pass filter, low pass filter, high-pass filter, look-up tables, averaging the demand signal in sub-time ranges.

3. The combined electrical power plant according to claim 2, wherein the smoothening process is repeated until the resulting first control signal provides response rates, power ramp rates and/or comprises nominal power values achievable with the thermal power generation facility within normal operation conditions and operation dynamics of the thermal power generation facility.

4. The combined electrical power plant according to claim 2, wherein the first control signal is adapted to minimize the CO₂-Emission of the combined electrical power plant during power generation to supply power in accordance to the demand signal.

5. The combined electrical power plant according to claim 1, wherein the plant controller is connected to the energy storage facility via a data connection receiving load data send-out by the energy storage facility about the current energy stored in the energy storage facility as a load feedback signal and takes into account the load feedback signal within the smoothening process for generation of first and second control signals.

6. The combined electrical power plant according to claim 5, wherein the load feedback signal is send-out and received periodically.

7. The combined electrical power plant according to claim 5, wherein the plant controller adapts the first control signal between first and second point in time to achieve a level of energy stored in the energy storage facility above a lower threshold value at least at the second point of time.

8. The combined electrical power plant according to claim 7, wherein the plant controller further adapts the first control signal between first and second point in time to achieve a level of energy stored in the energy storage facility below an upper threshold value at least at the second point of time.

9. The combined electrical power plant according to claim 8, wherein the level is adapted to 40-60% of the capacity of the energy storage facility after the thermal power generation facility passed a ramp-up phase, at least after passing the second point in time.

10. The combined electrical power plant according to claim 1, further comprising a point of connection to establish an electrical connection for providing the combined power output to the grid, wherein the point of connection is connected via a first power line to the thermal power generation facility and via a second power line to the energy storage facility, further comprising at least one measuring unit connected to the plant controller to monitor the power in the first power line supplied by the thermal power generation facility and being connected to the plant controller via another data connection to provide a first power line feedback signal to the plant controller, which is arranged to suitably adapt at least the second control signal in response to the first power line feedback signal in order to minimize differences between demand signal and the provided combined power output.

11. The combined electrical power plant according to claim 10, wherein the first power line feedback signal is provided periodically or continuously to the plant controller.

12. The combined electrical power plant according to claim 1, wherein the energy storage facility comprises a plurality of flywheels to supply or store the energy received from the thermal power generation facility or from the grid.

13. The combined electrical power plant according to claim 12, wherein the energy storage facility comprises an adaptable number of energy storage modules connected to each other each comprising multiple flywheels.

14. The combined electrical power plant according to claim 1, wherein the thermal power generation facility is one element of the group of coal-fired power station, gas fired power station or nuclear power station.

15. The combined electrical power plant according to claim 14, wherein the thermal power generation facility has a maximum output power of more than 5 MW.

16. The combined electrical power plant according to claim 1, wherein where the combined electrical power plant further comprises a communication interface to be connected to a external control system to receive the demand signal from the external control system.

17. A method to operate a combined electrical power plant according to claim 1 being connected to an electrical grid to supply electrical power to the grid comprising thermal power generation facility having a response time to supply a demanded amount of electrical power to the grid, which is limited by a thermal process, and an energy storage facility with a suitable energy storage capacity being able to supply additional electrical power to the grid and to receive and store electrical power from the thermal power generation facility or from the grid, both facilities are electrically coupled providing a combined power output to the grid in accordance to a demand signal specifies the demanded amount of power as a function of time between a first and a second point of time to be supplied to the grid, comprising the steps of

processing the received demand signal and generating at least a first control signal and a second control signal from the demand signal by a plant controller, where the first control signal is a smoothened function of time of the demand signal resulting from a smoothening process executed by the plant controller taking into account operational characteristics of the thermal power generation facility to operate the thermal power generation facility under optimized conditions, and where the second control signal is adapted to provide the combined power output in accordance to the demand signal;

transmitting the first control signal to the thermal power generation facility and supplying power to the grid in accordance with the first control signal by the thermal power generation facility;

transmitting the second control signal to the energy storage facility and supplying or receiving power in accordance to the second control signal, where the capacity of the energy storage facility is adapted to nominal power and ramp rate characteristics of the thermal power generation facility; and

providing the combined power output to the grid in accordance to the demand signal, where differences between combined power output and the demand signal are at least minimized at any point in time between the first and second points of time.

18. The method according to claim 17, where the smoothening process is repeated until the resulting first control signal provides response rates, power ramp rates and/or comprises nominal power values achievable with the thermal power generation facility within normal operation conditions and operation dynamics of the thermal power generation facility.

19. The method according to claim 17, further comprising the steps of

receiving load data send-out by the energy storage facility about the current energy stored in the energy storage facility by the plant controller connected to the energy storage facility via a data connection as a load feedback signal;

and

taking into account the load feedback signal for the smoothening process for generating the first and second control signals.

20. The method according to claim 19, further comprising the step of adapting the first control signal between first and second point in time in order to achieve a level of energy stored in the energy storage facility above a lower threshold value at least at the second point of time.

21. The method according to claim 19, where the load feedback signal is received periodically.

22. The method according to claim 17, wherein the combined electrical power plant comprises a point of connection to establish an electrical connection to the grid for providing the combined power output, wherein the point of connection is connected via a first power line to the thermal power generation facility and via a second power line to the energy storage facility, further comprising the steps of

monitoring the power supplied to the first power line by the thermal power generation facility by at least one measuring unit connected to the plant controller;

provide a first power line feedback signal to the plant controller by the first measuring unit connected to the plant controller via another data connection; and

suitably adapting at least the second control signal in response to the first power line feedback signal in order to minimize differences between demand signal and the provided combined power output.

23. The method according to claim 22, where the first power line feedback signal is provided periodically or continuously to the plant controller.

24. The method according to claim 17, further comprising the steps of

starting a ramping up phase of the thermal power generation facility according to the first control signal at a starting point of time earlier than the first point of time and storing the generated power in the energy storage facility until the first point of time is reached, where the starting point of time depends on ramp rate of the thermal power generation facility and level of energy stored in the energy storage facility;

supplying the power generated by the thermal power generation facility according to the first control signal to the grid after the first point in time; and

additionally supplying at least the energy stored in the energy storage facility to the grid at least between the first point of time and the point of time, when the thermal power generation facility finished the ramping up phase.

25. The method according to claim 24, further comprising the step of reducing the amount of energy stored in the energy storage facility to a lower threshold level before starting the ramping up phase of the thermal power generation facility.

26. The method according to claim 17, further comprising the step of receiving the demand signal from an external control system via a communication interface of the combined electrical power plant connected to the external control system.