BG2C-3015 Powerex

Application Notes BG2C Universal Gate Drive Prototype Board Description: The BG2C is a two channel gate drive circuit designed for use with high frequency optimized IGBT modules. The BG2C utilizes Powerex VLA513-01R hybrid gate drivers and VLA106 series DC-to-DC converters to provide efficient switching of modules rated up to 300A. The hybrid gate drivers include high speed opto-couplers with typical propagation delay times as short as 200ns for control signal isolation. The hybrid DC-to-DC converters provide fully isolated control power for each driving channel. Features: Applications: 3A or 5A Peak Output Current BG2C is designed for use with Powerex NFH series 2500VRMS isolation for control power and signals and CM***DUS-12F high frequency IGBT Standard AMP MTA .100 input connector modules. Operates from a single 15 VDC or 24 VDC supply Use VLA106-15242 DC-to-DC converter for Wide output voltage swing +15V/-8V operation with 15 VDC control power Low parts count only 17 parts for two channels Use VLA106-24242 DC-to-DC converter for Compact Size 2.7 x 2.4 (69mm x 61mm) operation with 24 VDC control power Ordering Information: BG2C-5015 is a kit with a bare BG2C board, two VLA513 and two VLA106-15242s BG2C is a bare PCB only BG2C Application Guide Gate Driver Peak Drive Minimum Typical Application* DC/DC Part Number Current (I ) R (IGBT Module Rating) Converter OP G VLA106-15242 For 15VDC Input VLA513-01R +/- 5A 2.0 Up to 600A VLA106-24242 For 24VDC Input * Compatible IGBT module depends on voltage rating, switching frequency and selected R . Refer to Powerex application notes for details. G Note: For high frequency applications using modules with current ratings larger than 300A, the Powerex VLA502-01 driver is recommended. Publication Date: 02-03-2016 1 Rev. 1 Application Notes Figure 1: VLA513-01R Block Diagram Figure 2: VLA106-15242, VLA106-24242 Block Diagram Circuit Explanation: The BG2C is a basic two channel gate driver designed around the recommended application circuits for the Powerex VLA513-01R hybrid IGBT gate drivers in combination with either VLA106-15242 or VLA106-24242 isolated DC-to-DC converters. A functional block diagram of the VLA513-01R hybrid gate drivers is shown for reference in Figure 1. These gate drivers are optimized for use with Powerex NFH series and CM**DUS-12F IGBT modules. The drivers use a high speed open collector type opto-coupler to provide 2500VRMS isolation of control signals. The output stage is designed to provide high current gate drive with the appropriate on- and off-state bias voltages for large IGBT modules. For additional detailed information on the characteristics and operation of these gate drivers please refer to the individual device datasheets. Figure 2 shows a block diagram of the VLA106-15242 and VLA106-24242 hybrid DC-to-DC converters. These two devices are identical except that VLA106-15242 is designed to operate from a 15 VDC input and the VLA106-24242 is designed to operate from a 24 VDC input. These DC-to-DC converters use a transformer to provide 2500VRMS isolation for gate drive power. The converters regulated 24VDC output is split using a resistor and zener diode to provide +15.8V and -8.2V for the hybrid gate driver. For additional detailed information on the operation of the hybrid DC-to-DC converters please see the individual device datasheets. A complete schematic and component selection guide for the BG2C is shown in Figure 3. The board will normally be operated with two input voltage sources. A 5V logic source (+V ) provides drive for the high speed L opto-couplers inside the hybrid gate drivers. A control power supply (+V ) provides power for the gate driver and S is connected to the primary side of the DC-to-DC converters at Pins 8, 9 and 10, 11. The +V source is decoupled S with a low impedance electrolytic capacitor C1. The capacitor is connected close to the input pins of the DC-to-DC converters to provide a stable, well-filtered DC source. A 390F capacitor was selected for C1 to provide the required ripple current and filtering assuming a maximum driven load and a significant distance to the main filter capacitor of the +V supply. These capacitors will be larger than necessary if the driven load is smaller or the V S S supply main filter capacitors are nearby. The DC-to-DC converters provide isolated gate drive power which consists of +15.8V (V ) at Pin 3 and -8.2 (V ) at Pin 1 with respect to common at Pin 2. The gate drive power CC EE supplies are decoupled using the low impedance electrolytic capacitors C2, C3, C4, and C5. It is very important that these capacitors have low enough impedance and sufficient ripple current capability to provide the required high current gate drive pulses. The 390F low impedance capacitors used on the BG2C are sized to supply 5A gate pulses at a 60 KHz rate. If the application is operating at lower frequency or lower peak current it may be possible to reduce the size of these capacitors. The isolated V and V supplies provided by the DC-to-DC converters are connected to the hybrid gate EE CC drivers at Pins 6 and 8 to provide gate drive power. The hybrid gate driver amplifies the control input signal and produces high current gate drive at Pin 7. The gate drive current is adjusted by selecting the appropriate series gate resistance (R ). R will normally be adjusted to provide suitable drive for the module being used G G considering dynamic performance, losses and switching noise. For more information on selecting R see Powerex G IGBT module application notes. Protection against gate voltage surges is provided by Z1, Z2, Z3, and Z4. These zener diodes also help to control short circuit currents by shunting miller current away from the gate. Publication Date: 02-03-2016 2 Rev. 1