Automatic System for the Control of Stability of an HVDC link - Implementation in Red Eléctrica de España (REE)

Authors: J Martin, Red Electrica de España (REE), C. de Arriba, J. Rodriguez, GE Grid Automation, and E. Leon, Siemens, Spain

Solution Proposed

A redundant system developed for two different manufacturers has been chosen to send to HVDC the command to monopole operation or disconnect the link, both systems must agree on disconnection and only one of them can command to monopole operation.

Manufacturer A: The solution implemented is based on synchrophasor technology, IEC61850 communications for commands, Phasor Data Concentrator (PDC) using GE_Power software Package which it has embedded the protocols IEC61850 Edition 2 Client/Server and IEEE C37.118 collecting raw data from the IEDs, a powerful Soft PLC processing the data and calculating the remedial actions sending the results in fast GOOSE messages to IEDs, and an operator HMI to visualize system condition and change the threshold levels without system disruption. The system architecture implemented is as seen in Figure 4, and its deployment can be observed in Figure 1.
In each substation is installed as Phasor Measuring Units (PMU) the device GE UR N60 to provide a synchrophasor information with analog data (voltage and current) and digital data (switchgear position), anomaly signals and bay alarms, and as IEEE C37.118 establishes, all synchronized through IEEE 1588 PTP provided by GE REASON RT430 clocks using as reference GPS and GLONASS constellations.
In the HVDC substation is installed a PDC where the information is processed, the calculation run, and finally a decision is taken and transmitted through IEC61850 GOOSE message to a GE UR N60 placed in this substation (PNSEC), which actuates to HVDC control system.  Also, this PDC repacks all synchrophasor information, changing its sample rate and sending to REE phasor control center in Madrid (Spain) in different synchrophasor frames. All the operation data, system status, alarms, events and trends can be seen in HMI placed in the same substation.

All the communication is in a dedicated LAN on each substation and interconnected to others with a dedicated SDH network with a maximum bandwith of 10Mbps creating a dedicated and redundant ASPAS grid for each manufacturer.
For a better maintenance purposes, and as a GOOSE communication is populated over the ASPAS grid, all GE UR N60 has signal systems on its front display leds. (Figures 1 and 5).

Manufacturer B:  The solution implemented is based on PMU (Phasor Measurement Unit), PDC (Phasor Data Concentrator) and PDP (Phasor Data Processor) technology, using the standard transmission protocol IEEE C37.118 to transmit the phasor values of voltages, phasor values of currents and binary signals from the PMU level, collect them in the PDC level, and process and use them in the PDP level with the required logics and application, having a powerful WAM (Wide Area Monitoring) and WAC (Wide Area Control) application with its inherent HMI to monitor the whole system. Furthermore, the solution uses control units as the interface between the PDP and the HVDC control system, using the standard protocol IEC 60870-5-104 to finally execute the required control commands (open commands, indications and alarms) in HVDC. 
All the collected information from IEDs, and the processed signals on the PDC are displayed on the local HMI to show the application in a friendlier and customized view.
The system architecture implemented is as seen in Figure 6.
As shown in the system architecture, an independent PMU is installed in each measurement point location, having used one of the devices of SIPROTEC 5 platform to measure the voltage and current values, collect the topology of the bays where the PMU are installed, and transmit the phasor values of voltage and currents as synchrophasors with the transmission protocol IEEE C37.118, as well as the binary information related to the topology of the bays, status of circuit breakers, and relevant alarms. The use of this platform as PMU allowed using only one IED for one or several PMU functions, instead of using as many IEDs as PMU functions were needed.

The PMUs are locally time synchronized with IRIG-B (IRIG-B 005(004) with extension according to IEEE C37.118) to get the PMU data streams time synchronized in the PDC.
In the upper level of this application, close to the HVDC control system, a PDC-PDP system is installed to collect, process and use the PMU values and carry out the required WAM-WAC application, having used SIGUARD PDP for such application.
Digital communication networks are used to establish the communication link between the PMU and PDC-PDP system, having used a dedicated SDH communication link for each PMU.
As an end user interface, a local HMI is built to get a global view of the WAM-WAC application, as well as its status, alarms and the sequence of events of the system, having used SICAM PAS and SCC for such customized HMI.
The standard protocol IEC 60870-5-104 is used to establish communication between the WAM-WAC system and the SICAM PAS, and then all the information is displayed on SICAM SCC.
Therefore, the whole system is based, as said before, in different PMU measurement point locations, a central PCP-PDC system with its inherent HMI to evaluate the system, three control units to transfer the control commands to the HVDC control system, and a customized HMI. (Figure 7).

Power. Flexible. Easergy.
BeijingSifang June 2016