Thailand-Malaysia

The Thailand-Malaysia HVDC project is an interconnection between the power grids of Thailand and Malaysia. This 300 MW HVDC system consists of two converter stations: one at Khlong Ngae in southern Thailand and another at Gurun in Malaysia. These stations are connected by a 110 km long 300 kV DC overhead transmission line, with approximately 24 km in Thailand and 86 km in Malaysia.

The project was initiated in 1997 when Tenaga Nasional Berhad (TNB) of Malaysia and the Electricity Generating Authority of Thailand (EGAT) signed a contract for its development. The interconnection became operational in October 2001, marking a major milestone in ASEAN power grid integration.

Technical Specifications

Technically, the HVDC system is configured as a monopolar converter with a capacity of 300 MW. However, provisions have been made to add a second 300 MW pole in the future, which would extend the system to a bipolar configuration with a total transfer capability of 600 MW. The system operates at a voltage level of ±300 kV.

The converter stations employ 12-pulse converters. The project incorporates several notable technical features, including DC active filters, triple-tuned AC filters, and point-on-wave switching of AC filters and transformers.

System Capabilities

The key role of this HVDC interconnection is to transfer power between the asynchronous AC systems of Thailand (230 kV, 50 Hz) and Malaysia (275 kV, 50 Hz).

The system is designed for bi-directional power flow, enabling both countries to export or import power as needed. It can operate at its rated capacity of 300 MW, with a maximum overload capacity of 450 MW for up to 10 minutes. This flexibility is particularly useful for managing peak loads and emergencies in both power systems.

Benefits of the HVDC Link

The HVDC link offers several important benefits. It allows for the sharing of spinning reserves between the TNB and EGAT AC systems, which improves overall system reliability. The interconnection also facilitates more economical power exchange between the two countries, taking advantage of their different daily peak consumption periods. Additionally, it provides emergency assistance to either AC network and offers reactive power support for voltage control in both AC networks.

Environmental Considerations

From an environmental perspective, the HVDC transmission system has a smaller footprint compared to an equivalent AC system. The transmission towers for DC lines are typically smaller and require less right-of-way, reducing the project's environmental impact.

Regional Significance

The Thailand-Malaysia HVDC project serves as a model for regional power integration and has paved the way for more ambitious interconnection proposals in Southeast Asia. It demonstrates the technical feasibility and economic benefits of cross-border power trading, contributing to the broader goals of the ASEAN Power Grid initiative.