|Shanghai Wanggang substation is a 220kV substation located at Pudong district, Shanghai. The substation is managed by Zhangqiao dispatching center. The substation has two (2) 180,000 kVA transformers, four (4) incoming supply lines of 220kV and nineteen (19) outgoing feeders of 35 kV.
The existing interlocking system deployed in the Shanghai Wanggang substation is an offline system, the Smart Key is unaware of the primary equipment status changes during the operation. Without real-time communication between Smart Key and Smart Interlock System host, the interlocking system can only enforce a series of predefined orders without validating each step. Meanwhile a single operation can only be stored in a single Smart Key. Operators are required to travel back and forth between control room and the field frequently for a complicated switching task. All these shortcomings greatly constrained switching operation efficiency.
Unitech JOYO series Smart Interlock System achieves the following benefits:
■ Real-time status update on Smart Interlock System Host
■ Real-time validation and authorization before each switching steps
■ Unique operation privilege enforcement
■ Video monitoring of primary equipment during operation
■ Reduced operation workload and training cost
JOYO-B43 Smart Interlock System was the answer to above challenges。 JOYO series smart interlock system features a five step process that incorporate simulation before switching and step by step validation。
Step 1: Simulation
Operation orders are simulated on SIS Host to verify its correctness. SIS host consists of a rule database and one line diagram of primary equipment that will facilitate the simulation, thus prohibits any faulty switching operation.
Step 2: Transmission
Once the operation procedure is validated on SIS host, the electronic switching order will be generated and transmitted to the Smart Key. There are two types of communication methods supported between Smart Key and SIS host, wired bus connection and low power consumption wireless communication. The operator is ready for field work once the transmission is finished.
Step 3: Device Verification
By following the instruction showed on Smart Key, the field operator can easily locate designated devices。 Before any actual operation, the device must be identified by the Smart Key。 In order to achieve universal identification, RFID is embedded in locking mechanism of each device。
Step 4: Operation Validation
Instead of following a predefined procedure, once the device is verified, the Smart Key will send a request to SIS host to validate the operation. SIS host will make the decision based on real-time equipment status, which is much safer than assuming the system will preserve previous status. Also, the SIS host will ensure only one operator can request operation on a particular equipment at any given time.
Step 5: Switching
Once the switching operation takes place, SIS host will be aware of any primary equipment status change directly through acknowledgement from Smart Key or indirectly from SCADA/EMS system.