阅读说明：本技术 用于功率系统稳定性的电力发电机选择、卸载和减负荷 (Power generator selection, offloading and offloading for power system stability ) 是由 克里什南简·古巴拉维库马 本杰明·E·阿姆斯特朗 马兹·赛义德·穆罕默德·卡兹米 于 2019-01-18 设计创作，主要内容包括：本公开提供用于管理电力输送系统的系统和方法。该系统和方法可以限制电力输送系统的发电功率超过负载需求,以避免系统不稳定。该系统和方法可以接收过量发电值,并管理发电机以减负荷和/或卸载来将过量发电保持在阈值以下。该系统和方法可以确定用于减负荷的多个发电机组。这些发电机的减负荷容量可与过量发电进行比较。如果过量发电不大于减负荷容量,则该系统和方法可以选择发电机组,直到所选择的组的减负荷容量大于过量发电,并且可以根据减负荷设定点使那些发电机减负荷。未被选择的发电机可以继续正常操作,以便可用于另一个减负荷请求。(The present disclosure provides systems and methods for managing power delivery systems. The system and method may limit the generated power of the power delivery system beyond the load demand to avoid system instability. The system and method may receive the excess generation value and manage the generator to shed and/or unload to maintain the excess generation below a threshold. The system and method may determine a plurality of generator sets for load shedding. The unloading capacity of these generators can be compared to excess power generation. If the excess generation is not greater than the derated capacity, the systems and methods may select the generator sets until the derated capacity of the selected set is greater than the excess generation, and may derate those generators according to the derating set point. The unselected generators may continue to operate normally so as to be available for another load shedding request.)

1. A system for managing an electric power delivery system, comprising:

a communication interface for receiving signals from the power delivery system and transmitting signals to modify power generation by a plurality of generators;

one or more processors configured to:

determining a plurality of generator sets, each generator set comprising a unique set of one or more of the plurality of generators;

determining excess power generation (EG) of the power delivery system based on load information in a signal from the power delivery system;

if EG is less than or equal to the load shedding capacity (RC) of the plurality of generators:

selecting one of the plurality of generator sets according to a predetermined ordering; and

the following is done until EG is greater than a selected load Reduction (RS), where RS is a group load Reduction Capacity (RC) of the selected group_g) Sum of (a):

selecting a next generator set of the plurality of generator sets according to the predetermined ordering; and

setting RS equal to RC of itself plus next selected genset_g；

If EG is less than or equal to RS:

setting a load shedding set point for each generator in the selected genset; and

sending a signal through the communication interface to de-load each generator in the selected genset in accordance with the de-load set point.

2. The system of claim 1, wherein the one or more processors are further to:

if EG is greater than RC for the plurality of generators:

determining a set of generators of the plurality of generators to offload; and

sending a signal to disconnect the set of generators from the power delivery system.

3. The system of claim 2, wherein the set of generators of the plurality of generators to be offloaded is determined according to a best choice algorithm.

4. The system of claim 3, wherein the best selection algorithm comprises:

evaluating a ranking of candidate generator sets from the plurality of generators to determine an optimal generator set to offload.

5. The system of claim 3, wherein the best selection algorithm comprises:

determining a maximum number (MAX) of generators meeting the unloading requirement; and

evaluating a ranking of candidate generator sets from the plurality of generators to determine an optimal generator set to offload,

wherein the number of generators in each permutation of the candidate set is less than or equal to MAX.

6. The system of claim 1, further comprising an emergency circuit breaker in communication with the communication interface for receiving an overload condition signal and tripping based on user preference and sending a signal to the system.

7. The system of claim 1, further comprising an emergency circuit breaker configured to trip and send a signal to the system based on a predetermined criteria.

8. The system of claim 1, further comprising a plurality of Intelligent Electronic Devices (IEDs) in communication with the system, each IED corresponding to one of the plurality of generators for receiving signals from the system and providing signals to the generators to offload the generators or to de-load the generators according to the de-load set-point.

9. The system of claim 1, wherein the load shedding setpoint for each given generator in the selected generator set is based on P_g-EG(RC_g/RC) where P is_gIs the power of a given generator.

10. The system of claim 1, wherein the load shedding setpoint for each generator in the selected genset is set according to a proportion of RC within the generator.

11. A method for managing an electrical power delivery system including a plurality of electrical generators, the method comprising:

determining a plurality of generator sets, each generator set comprising a unique set of one or more of the plurality of generators;

determining excess power generation (EG) of the power transmission system based on load information received via signals from the power transmission system;

if EG is less than or equal to the load shedding capacity (RC) of the plurality of generators:

selecting one of the plurality of generator sets according to a predetermined ordering; and

the following is performed until EG is greater than a selected load Reduction (RS), where RS is a group load Reduction Capacity (RC) of the selected group_g) Sum of (a):

selecting a next generator set of the plurality of generator sets according to the predetermined ordering; and

setting RS equal to RC of itself plus next selected genset_g；

If EG is less than or equal to RS:

for each generator in the selected generator set, setting a load shedding set point according to the proportion of RC within the generator; and

sending a signal through a communication interface to de-load each generator in the selected genset in accordance with the de-load set point.

12. The method of claim 11, further comprising:

if EG is greater than RC for the plurality of generators:

determining a set of generators of the plurality of generators to offload; and

sending a signal to disconnect the set of generators from the power delivery system.

13. The method of claim 12, wherein determining the set of generators to offload comprises an optimal selection algorithm comprising evaluating a ranking of candidate sets of generators from the plurality of generators to determine an optimal set of generators to offload.

14. The method of claim 12, wherein determining the set of generators comprises:

determining a maximum number (MAX) of generators meeting the unloading requirement; and

evaluating a ranking of candidate generator sets from the plurality of generators to determine an optimal generator set to offload,

wherein the number of generators in each permutation of the candidate set is less than or equal to MAX.

15. The method of claim 11, further comprising:

receiving one or more overload condition signals at an emergency circuit breaker; and

tripping the emergency circuit breaker based on user preferences and the one or more overload condition signals.

16. The method of claim 11, wherein the load shedding setpoint for each given generator in the selected genset is based on P_g-EG(RC_g/RC) where P is_gIs the power of a given generator.

17. The method of claim 11, wherein the load shedding setpoint for each generator in the selected genset is set according to a proportion of RC within the generator.

18. A system for managing power generation offloading on a microgrid, comprising:

an emergency circuit breaker to receive an over-generation condition signal indicating that the microgrid is generating excess power in excess of the power collectively consumed by loads connected to the microgrid, wherein the emergency circuit breaker is tripped based on user preferences and the over-generation condition signal;

an Intelligent Electronic Device (IED) in communication with the emergency circuit breaker and the plurality of generators on the microgrid, the IED to:

determining a plurality of generator sets, each generator set comprising a unique set of one or more of the plurality of generators;

calculating excess power generation (EG) on the microgrid;

if EG is less than or equal to the load shedding capacity (RC) of the plurality of generators:

selecting one of the plurality of generator sets; and

the following is performed until EG is greater than a selected load Reduction (RS), where RS is a group load Reduction Capacity (RC) of the selected group_g) Sum of (a):

selecting a next generator set of the plurality of generator sets according to a predetermined ordering; and

setting RS equal to RC of itself plus next selected genset_g；

If EG is less than or equal to RS:

for each generator in the selected generator set, setting a load shedding set point according to the proportion of RC within the generator; and

sending a signal through a communication interface to de-load each generator in the selected genset in accordance with the de-load set point.

19. The system of claim 18, wherein the IED is further configured to:

if EG is greater than RC for the plurality of generators:

determining a set of generators of the plurality of generators to offload; and

sending a signal to disconnect the set of generators from the power delivery system.

20. The system of claim 19, wherein the IED determines a set of generators with a minimum of generators, and

wherein the signal to disconnect the set of generators comprises unloading the set with the least generators.

21. The system of claim 19, wherein the signal to disconnect the set of generators comprises sending a signal to a circuit breaker to trip the circuit breaker to disconnect a given generator from the microgrid.

22. The system of claim 18, wherein the load shedding setpoint for each given generator in the selected generator set is based on P_g-EG(RC_g/RC) where P is_gIs the power of a given generator.

23. The system of claim 18, wherein the load shedding setpoint for each generator in the selected genset is set according to a proportion of RC within the generator.

Technical Field

The present disclosure relates to systems and methods for controlling and protecting power delivery systems, and more particularly, to power generation offloading (shed) and unloading (runback) systems and methods to limit the actions that result in over-unloading of power generation and to improve the survivability of a plant during an unloading event.