• sft1235 posted an update 11 months, 3 weeks ago

    Conversion Combined Linear Tap Changer
    Disclosed is an End-Turn Solid-State Switching (ETSS) transformer tap which makes use of a high-speed solid-state switching network to select either the end-turn lead or one of a number of non-isolated taps on a transformer regulating winding, and connects the selected tap to, while disconnecting the previously selected tap from, a single output conductor carrying the transformer load current. ETSS effectively changes the reference to one of the possible taps interfaced to a solid-state switching network. The same transformer regulating winding connected to ETSS can also be connected in series with a slow-speed mechanically-switched tap-changer (LTC). ETSS selects one connection point on the regulating winding while LTC operation selects the second point.
    A difference voltage is produced, depending on the number of turns between the ETSS selected tap and the LTC selected tap. The sign of the difference in voltage depends on whether the ETSS selected tap is higher or lower than the LTC selected tap. The difference or tap selected voltage is in series with the transformer load current. In one embodiment, the high-speed solid-state switching network uses a “Staggered Progression of Solid-State Switches” (SPSS) to select one of a number of non-isolated taps on a transformer regulating winding and connect the selected tap in series with the load circuit. A switching network arranged according to the method SPSS reduces the necessary total switch power rating, and steady-state losses. ETSS can accomplish modulation of the tap-selected voltage about the nominal value established by the LTC
    Model Explanation
    WST □ – □/□-□╳□
    W: off-circuit
    S : three-phase or D for single phase
    T : linear type tap chager
    □: voltage regulation model
    □: rated current
    □: rated voltage
    □: number of tapping heads
    □: number of tapping position
    Voltage Regulation Model
    I : terminal point
    II : central point
    III : neutral point
    IV : Y-△ conversion
    V : series-parallel connection
    Samples Technical Data
    SpecificationsWST 30WST 63WST 125WST 250WST 400WST 500
    Phase numberthree-phases
    Connection modeCentral point(Ⅱ) Neutral Point(Ⅲ) Terminal Point(Ⅰ)
    Rated through current(A)3063125250400500
    Short-circuit capacityHeat stableness current(KA/2s)
    Dynamic stableness current(KA)1.846.259.3751012.5
    Rated frequency50~60
    Insulation level(KV)Rated Voltage10KV20KV35KV
    Power-frequency withstand Voltage(50Hz/1min)42KV55KV95KV
    Sealing Performance(KPa/24h)60
    Machine life(Thousands of times)2China Y-∆ Tap Changer