TNAG-1058-FCO40-1308-Guangdong-nuclear-power-station-project-1981 — Page 78

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3.1.4

The nuclear power station would be connected directly to the GPC and CLP networks by one 500 kV 1800 MVA overhead line circuit to Dongjiao Substation and one 400 kV 1800 MVA overhead line circuit to Tai Po Substation respectively. The power station would further be connected by one 400 KV (constructed to 500 kV design) 1350 MVA overhead line circuit to Liantang Substation, a new substation to be established in the Shenzhen area, which would in turn be connected to the GPC and CLP networks by one 500 kV 900 MVA overhead line circuit to Dongjiao Substation and one 400 kV 1800 MVA overhead line circuit to Yuen Long Substation respectively. Transformation facilities would be installed at the nuclear power station and Liantang Substation for interconnection of the 500 kV and 400 kV systems.

The technical performance of the selected transmission system has been studied in detail by carrying out power flow, security assessment, fault level, transient stability and steady state stability studies. These studies indicate that the system would perform satisfactorily under normal and outage conditions.

System Operation

After commissioning of the nuclear power station, the GPC and CLP power systems would, in principle, be independently despatched. Each system would regulate their own generation to follow the respective system demand and maintain the agreed share of output from the nuclear power station. Each system would carry adequate spinning reserve to cover normal regulation requirements and credible contingencies. The sharing of output from the nuclear power station and transfer between the GPC and CLP would be effected by frequency biased tie-line control.

It is noted that substantial economic advantages can be gained by taking advantage of the interconnection between GPC and CLP and the characteristics of the demands of the two systems (e.g. differences in the daily and seasonal load cycles). In view of this, it is felt that the feasibility of economic power transfer between GPC and CLP should be pursued as a separate issue.

3.1.5

Generating Capacity Reliability

The generating capacity reliability of the GPC and CLP power systems after commissioning of the nuclear power station has been studied using the Loss of Load Probability method. The study shows that :

(a) With the generation development presently planned and 40% of the nuclear power station output (i.e. 2 x 360 MW), the generating capacity reliability of the GPC system in 1989/90 is found relatively low. It is estimated that a satisfactory level of reliability can be achieved by taking measures such as interconnection with the Guangxi system or

installation of 2 x 200 MW sets.

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