|Guangdong Chaoyang substation is located at Shantou, Guangdong which covers voltage level of 220kV, 110 kV and 10 kV. The substation has two (2) 240,000 kVA transformers, four (4) incoming supply lines of 220kV, eleven (11) outgoing feeders of 110 kV and twenty (20) outgoing feeders of 10 kV.
The interlocking systems deployed in the Guangdong Chaoyang substation are electro-magnetic interlocking system and mechanical systems. These conventional interlocking methods have the following constraints that greatly impact the switching operation safety.
■ Interlocking logic is limited to within each bay unit, thus it does not guarantee that switching personnel operates on the correct device.
■ Interlocking logic is designed prior to installation, thus locks need to be re-designed and installed for primary equipment change.
■ Interlocking logic cannot be applied to complicated operations involving multiple bays, such as energizing secondary bus bar, switching from primary to secondary bus bar, equipment maintenance etc.
■ Switching operations may require many keys for different locks. Key usage cannot be tracked and expensive to replace lost keys.
■ Interlocking device cannot be installed on all primary equipment due to cost and scalability.
Comparing to traditional mechanical or electric-magnetic interlock, Smart Interlock System achieves following benefits:
Field operators interact with equipment through a single interface: the Smart Key. Operators may use a single smart key to access both mechanical pad locks and circuit controlled breakers, thus avoiding complexities and confusions brought by traditional means of interlocking.
SIS is highly flexible to suit ever changing requirements. Primary equipment change no longer requires re-design of existing interlocking system. Rules and diagrams can be configured easily to cope with emerging new requirements.
The scope of SIS ranges from single unattended substation to major dispatching centers. The complexity of deployment does not scale exponentially like electrical-magnetic circuit design.
Most importantly, SIS is much safer than traditional interlocking systems such as mechanical interlocks or electric-magnetic interlocks. This is because SIS takes whole system and related rules and regulations as integrity. Instead of enforcing operation procedures on a single block, SIS assesses the impact to the whole system of each single operation to prevent possible accidents.
JOYO-B43 Smart Interlock System was the answer to above challenges.
Smart Interlock System software catches all details of substation as integrity. The software uses AMEO programming language to express switching interlocking logic and rules of all primary and secondary equipment. As the result, Smart Interlock System coverage is no longer limited to within a breaker bay. Through communication with RTU, the software displays the one line diagram of the substation with real-time status update. Thus it enables the simulation before switching process that guarantees the correctness of switching order. Each step of operation order is checked during simulation to measure possible impact across the whole substation. Upon receiving an operation order, the field operator simply simulates the operation order on SIS host to verify its correctness, and then take the smart key to the field to perform exact steps of simulated operation order. All possible lock points are taken care by most suitable locking mechanism, from regular padlock to control circuit lock. During the entire switching task, there’s only one lock point can be accessed by the smart key at any given time.