CONTROL METHOD, AND CONTROL SYSTEM FOR A SUBSTATION

Abstract

A technique for a control method and a control system in a substation is provided. The control system includes a substation feeder, an intelligent electronic device, IED, a merging unit, and BUS network connecting the IED and the merging unit. The control method includes providing measurement signals by the substation feeder to the merging unit, transmitting, by the merging unit, measurement data based on the measurement signals of the substation feeder to the IED via the BUS network, identifying, by the IED, a fault condition based on the measurement data, transmitting, by the IED, a conditional control command to the merging unit via the BUS network, determining, by the merging unit, whether the condition of the conditional control command is met, and if so initiating, by the merging unit, the control measure of the substation feeder circuit.

Claims

1. A control method for a control system in a substation, the control system comprising a substation feeder, an intelligent electronic device (IED) a merging unit, and a Binary Unit System (BUS) network connecting the IED and the merging unit, the control method comprising: providing measurement signals by the substation feeder to the merging unit; transmitting, by the merging unit, measurement data based on the measurement signals of the substation feeder to the IED via the BUS network; identifying, by the IED, a fault condition based on the measurement data, the fault condition being indicative of a potentially forthcoming fault; transmitting, by the IED, a conditional control command to the merging unit via the BUS network, the conditional control command comprising a control measure and a condition for executing the control measure; determining, by the merging unit, whether the condition of the conditional control command is met; and if so initiating, by the merging unit, the control measure of a substation feeder circuit.

2. The control method of claim 1, wherein the control system comprises at least one second merging unit and at least one second substation feeder, the BUS network connecting the IED and the at least one second merging unit, the method further comprising: providing measurement signals by the at least one second substation feeder to the at least one second merging unit; and transmitting, by the at least one second merging unit, second measurement data based on the measurement signals of the at least one second substation feeder to the IED via the BUS network.

3. The control method of claim 1, wherein transmitting the conditional control command via the BUS network complies with a hierarchical communication protocol, and wherein the merging unit is located at a lower hierarchical level than the IED within the hierarchical communication protocol.

4. The control method of claim 1, further comprising: encoding the condition of the conditional control command in a codelet by the IED and transmitting the codelet by the IED to the merging unit via the BUS network; and processing the codelet by the merging unit.

5. The control method of claim 1, wherein the condition of the conditional control command comprises a specified reaction time period until initiation of a protection measure.

6. The control method of claim 1, wherein the condition of the conditional control command comprises a specified fault threshold for the measurement data.

7. The control method of claim 1, wherein the condition of the conditional control command comprises a control decision model based on measurement data, the control decision model comprising a zero-crossing condition for a measured current and/or voltage.

8. The control method of claim 1, wherein the measurement signals comprise at least one of a voltage signals, current signals, temperature signals, and frequency signals.

9. The control method of claim 1, wherein the control measure comprises operating at least one switchgear bay of the substation.

10. The control method of claim 1, further comprising identifying, by the IED, a no-fault condition based on the measurement data, the no-fault condition being indicative of the conditional control command being no longer necessary; and transmitting, by the IED, a cancel command for cancelling the conditional control command to the merging unit.

11. A merging unit for a control system for a substation, the merging unit comprising: a feeder-facing interface configured to receive measurement signals from at least one substation feeder of the substation; a signal converter configured to provide measurement data based on the measurement signals of the at least one substation feeder; a Binary Unit System (BUS) interface configured to transmit the measurement data via a BUS network to an intelligent electronic device (IED) and to receive a conditional control command from the IED, wherein the conditional control command comprises a control measure and a condition to execute the control measure; and logic configured to determine whether the condition of the conditional control command is met, and if so, to initiate the control measure of the substation feeder circuit.

12. A control system for a substation, the control system comprising: at least one substation feeder with sensors configured to provide measurement signals; at least one merging unit according to claim 11; an IED; and a BUS network connecting the at least one merging unit with the IED, wherein the IED has a BUS interface configured to receive the measurement data; logic configured to identify, based on the measurement data, a fault condition indicative of a potentially forthcoming fault and configured to provide a conditional control command, wherein the BUS interface is configured to transmit the conditional control command via the BUS network to the at least one merging unit.

13. The control system of claim 12, wherein the BUS network between the IED and the merging unit complies with a hierarchical communication protocol, and wherein the at least one merging unit is located at a lower hierarchical level than the IED within the hierarchical communication protocol.

14. The control system of claim 12, wherein the conditional control command is encoded as a codelet, and wherein the merging unit has logic configured to carry out the codelet.

15. The control system of claim 12, further comprising at least one switchgear bay, the switchgear bay comprising at least one of a circuit breaker, a disconnector, a load switch or a switch disconnector, the control measure comprising a control action.

16. The control method of claim 9, wherein the switchgear bay includes at least one of a circuit breaker, a disconnector, a load switch or a switch disconnector, the operating comprising a control action.

17. The control system of claim 13, wherein the conditional control command is encoded as a codelet, and wherein the merging unit has logic configured to carry out the codelet.

18. The control system of 13, further comprising at least one switchgear bay, the switchgear bay comprising at least one of a circuit breaker, a disconnector, a load switch or a switch disconnector, the control measure comprising a control action.

19. The control system of 14, further comprising at least one switchgear bay, the switchgear bay comprising at least one of a circuit breaker, a disconnector, a load switch or a switch disconnector, the control measure comprising a control action.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 illustrates a schematic diagram of a control method for a control system in a substation according to an embodiment of the present disclosure;

[0038] FIG. 2 illustrates a schematic diagram of a BUS network of a substation complying with a hierarchical communication protocol according to an embodiment of the present disclosure; and

[0039] FIG. 3 illustrates a schematic circuit diagram of a control system for a substation according to embodiments of the present disclosure.

DETAILED DESCRIPTION

[0040] In the following, embodiments are set forth to describe specific examples presented herein. The person skilled in the art will recognize that one or more other examples and/or variations of these examples may be practiced without all the specific details outlined below. Also, well known features may not be described in detail so as not to obscure the description of the examples herein. For the ease of illustration, like reference numerals are used in different figures to refer to the same elements or additional instances of the same element.

[0041] Referring now to the drawings, FIG. 1 illustrates a control method 100 for a control system in a substation. The control system and its components which include a substation feeder, an intelligent electronic device, IED, a merging unit, and BUS network connecting the IED and the merging unit are described in more detail with reference to FIG. 3 below. FIG. 1 with its horizontal arrangement of boxes is intended to illustrate the control system's component carrying out the respective method step. Thereby, the method step symbolized by the box furthest left is carried out by a substation feeder; the method steps symbolized by the middle boxes are carried out by the merging unit; while the method steps symbolized by the boxed furthest right are carried out by the IED.

[0042] The control method 100 includes providing measurement signals 10 by the substation feeder to the merging unit. In step 12, the method provides for transmitting, by the merging unit, measurement data based on the measurement signals of the substation feeder to the IED via the BUS network. Next, the method foresees identifying 14, by the IED, a fault condition based on the measurement data, the fault condition being indicative of a potentially forthcoming fault, and transmitting 16, by the IED, a conditional control command to the merging unit via the BUS network 38a, 38b, the conditional control command including a control measure and a condition for executing the control measure. Lastly control method 100 provides for determining 18, by the merging unit, whether the condition of the conditional control command is met, and if so initiating 20, by the merging unit, the control measure of the substation feeder circuit.

[0043] Referring now to FIG. 2, a schematic diagram of a BUS network of a substation complying with a hierarchical communication protocol according to an embodiment of the present disclosure is illustrated. As shown, the hierarchical communication protocol connects different levels, with the merging units MU being allocated at a lower level and the IED being allocated at a higher level. Lastly, a human-machine interface HMI, supervisory control and data acquisition SCADA and/or gateway are allocated at the highest level. Although multiple IED are shown, some embodiments may provide for a single, centralized IED within entire substation. In this case, the IED provides for substation-wide visibility. The IED is configured to send and install codelet, via the hierarchical communication protocol, to a single or multiple merging units. The hierarchical communication protocol can be an extension to above-described GOOSE model, or any other suitable hierarchical protocol.

[0044] Referring now to FIG. 3, a schematic circuit diagram of a control system 300 for a substation according to the present disclosure is illustrated. The components of control system 300 include a substation feeder 30 with sensors 32 for providing measurement signals and a switchgear bay 40 for operating a control action. The switchgear bay is configured for operating a control action, such as to separate the feeder 30 from the substation if the feeder 30 is faulted. Likewise, the switchgear bay can close a breaker after a fault is resolved.

[0045] The control system 300 further includes a merging unit 34, an IED 36, and a BUS network 38a, 38b. Although only one merging unit is displayed, the principles described herein apply equally to a control system with more than one merging unit. The BUS network 38a, 38b connects the merging unit 34 with the IED 36. The BUS network provides for two connections 38a and 38b. Connection 38a serves for transmitting the measurement data, in some cases complying with SMV, to the IED 36, while connection 38b serves for transmitting the conditional control command to the merging unit by the IED, the conditional control command including a control measure and a condition for executing the control measure. In some cases, connection 38b complies with GOOSE, in other cases connection 38b complies with an extension to GOOSE such that a hierarchical communication protocol between the IED 36 and the merging unit 34 is established, in yet other cases, connection 38b complies to a hierarchical communication protocol irrespective of GOOSE.

[0046] Interfaces of the merging unit 34 and the IED 36 are not illustrated with separate reference sign for reasons of clarity, but are located at the arrows' endpoints, respectively. In particular, the merging unit 34 has a feeder-facing interface for receiving the measurement signals from the sensors 32 of the substation feeder 30 and for initiating control measure by the switchgear by 40. To connect to the BUS network, the merging unit 34 has a BUS interface for transmitting the measurement data via the BUS network to the IED 36 and for receiving the conditional control commands by the IED. The IED 36 also has a BUS interface for receiving the measurement data and for transmitting the conditional control command via the BUS network to the merging unit 34.

[0047] Embodiments and/or features described herein with respect to the control method may be implemented equally within the control system and vice versa.