Press-Pack package
Characteristics of PPIs
Electrical connections using pressure
Multiple IEGT chips are placed in an array on the same plane, and individual IEGT chips are uniformly pressed from both sides using a molybdenum plate. The collector and emitter electrodes of each IEGT chip are brought into contact with the corresponding copper electrodes of the press pack enclosure via the molybdenum plate by applying mechanical pressure. This not only makes electrical connections and but also allows heat dissipation.
High reliability due to hermetic sealing
Inert gas is hermetically sealed inside the press pack in order to prevent electrodes from being degraded due to oxidation. Thus, PPIs provide high thermal reliability.
Outstanding parallel operation technology
The wiring inside the gate terminal plate is designed to switch all the parallel IEGT chips simultaneously so that they will not interfere with each other and oscillate when switching.
Rupture-resistant package structure
IEGT chips are positioned on a resin frame to make them less prone to rupture even if a chip is melt and destroyed during switching.
PPI Installation Example
In the example shown at right, three series-connected PPIs are vertically stacked.
The PPI are placed between cooling fins, and pressure is applied from above and below to hold them firmly. An elaborate setup is necessary to ensure that pressure is uniformly applied across the PPIs. The spring helps reduce thermal contraction to keep a constant pressure.
Application Examples
Converters for High-Voltage Direct-Current (HVDC) Transmission
HVDC transmission is utilized to efficiently transmit renewable energy captured in remote places, for example, windmills on the sea, to the sites where energy is used. The generated AC voltage is converted to DC voltage and transmitted ashore over long distances or via submarine power cables. At the receiving end, the DC voltage is converted back into AC voltage to feed electricity consumers. PPIs are used for high-voltage converters.
Static VAR Compensators (SVCs)
SVCs are electrical equipments for improving electricity quality (e.g., power factor correction) on transmission networks. PPIs are utilized as high-voltage, high-current power devices for active SVC applications such as static VAR generators (SVGs) and static synchronous compensators (STATCOMs).
Medium-Voltage Inverters
PPIs, which allow series connection and double-sided cooling, are ideal for high-capacity inverter applications.