The IGC2.7 IGBT chopper control board is based on the IGC2.1 IGBT single tube driver board with PWM pulse formation, external fault (overcurrent, overvoltage, overspeed, etc.) protection circuit, driver stage undersaturation, short circuit Compared with the IGC2.1 single-tube driver board, the capacity of the IGBT that can be driven is greatly improved and the performance is more complete.
II. Main technical indicators
1. SG3526 is used as a PWM pulse forming chip, so the output PWM pulse frequency can be adjusted from 2 to 200kz;
2. The IGBT dedicated thick film driver HL403B is used as the core chip, and the additional power amplification enables it to drive IGBT single-tube modules with a capacity within 600A/1200V;
3. On the basis of the IGC2.1 single-tube driver board, an external circuit failure (overcurrent or overvoltage) protection and a self-holding circuit for protection of the final stage soft turn-off, gate voltage drop, undersaturation, etc. are added to make the driven IGBT run more quickly. The safe condition makes the protection function faster and more perfect;
4. The compact structure, small size of the control board and reasonable wiring meet the needs of high-frequency work;
5. It can be used to drive single-tube power IGBT in the energy consumption braking circuit of DC chopper, AC speed regulation or DC speed regulation;
6. External circuit failure protection input voltage signal (1゛12V/50mA);
7. Working power supply voltage: three-channel AC double 20V/0.2A and one-channel 22V/0.1A;
8. Maximum output load capacity (＼15V) 20mA;
9. It can be externally controlled (outside the board) and internally controlled (inside the board) to adjust the duty cycle of the PWM pulse (10% to 100%), and the input voltage signal for adjusting the width of the PWM pulse during external control is 0 to 5V;
10. The external dimensions are: length〜width〜height=187mm〜107mm〜30mm.
11. The installation hole distance size is: length〜width〜height=177mm〜94mm, and the installation hole distance is 4-φ4.5.
3. User instructions and usage methods
The schematic diagram of the component layout of the IGC2.7 IGBT single tube driver board is shown in Figure 1. It can be seen from the figure that there are 4 adjustable potentiometers and 3 input and output connectors in its board. Now introduce its function, wiring and adjustment methods respectively.
1. The function and adjustment method of each potentiometer
P1 is the user fault (overvoltage, overcurrent, overspeed, etc.) protection threshold adjustment potentiometer. Adjust the protection threshold clockwise to decrease and counterclockwise to increase the protection threshold; P4 is the user fault signal equivalent actual sampling value adjustment potentiometer, Adjust the equivalent sampling value clockwise to increase, and adjust the equivalent sampling value counterclockwise to decrease; P2 is the given potentiometer on the board, adjust the width of the output PWM pulse clockwise to decrease, and adjust the width of the output PWM pulse to increase counterclockwise. ; P3 is the output PWM pulse frequency adjustment potentiometer, clockwise adjusts the output PWM pulse frequency to increase, and counterclockwise adjusts the output PWM pulse frequency to decrease.
2. External wiring method of each connector
(1) The a, GND, and b of the connector S1 are connected to the secondary winding of the power transformer, and the required voltage is double 18V, the middle tap is connected to GND, and the two 18V with opposite polarities are respectively Connected to a and b; L1 and L2 in S1 respectively provide level signals for blocking the user system or user system synchronization under fault (external fault) protection conditions, where L1 is high in the normal state, and low in the protection state Level, and L2 is just the opposite of L1; I1 is connected to the output signal of the Hall current sensor, and I2 is connected to the sampling reference ground of the Hall current sensor.
(2) GND, +15V, -15V in the connector S2 are respectively connected to the reference ground, positive power supply and negative power supply connection terminals required for the operation of the Hall current sensor, and the maximum current available for ＼15V is 20mA. The P, G and GND terminals of S2 can be connected to a potentiometer with a resistance value of not less than 10k and a power of not less than 1W as a setting for external control of the PWM pulse width. At this time, the P2 middle header in the board should be disconnected to avoid The P2 in the board and the external potentiometer affect each other. It should be noted that G is connected to the middle of the potentiometer, and P and GND are connected to its two fixed ends respectively.
(3) C, G, E in the connector S3 are respectively connected to the collector, gate and emitter of the driven power IGBT, and with the difference of the driven IGBT, the resistance value of the resistor R24 ??connected to the board should be The recommended values ??are listed in the table below.
Figure 1 IGC2.7 type driver board component arrangement diagram (click on the above picture to enlarge)
| In order to avoid interference and make the driven IGBT work reliably, it is recommended that the lead from S3 to the IGBT gate-emitter should be shorter than 0.5m, and the two points G and E lead out As far as possible, use twisted pair or coaxial cable shielded wire as the root wire. At the same time, it should be noted that under the same capacity, because the gate parameters of IGBTs produced by different companies are different, the final value of R24 should be the best performance of the driven IGBT (that is, the Vce overshoot peak voltage and conduction A compromise between several factors of on-off and off-voltage drop) is the best. The F and D in the connector S3 are connected to the working power supply of the driver stage. The power supply can be direct current (+28V/0.2A) or alternating current (20V/0.2A). In order to minimize interference, it is recommended to use twisted-pair wires or lead wires from the DC power supply (if DC is connected between F and D) or the secondary side of the AC power transformer (if AC is connected between F and D) to the S3 socket. Coaxial cable is shielded, and the lead is as short as possible. The remaining A and B are normally closed contact signals (contact capacity 380V/0.5A or 220V/1A) given after the user system fault protection, so that the user can use this contact to break the main circuit of the user system.
|Four. Application examples
Picture2 IGC2.7 type IGBT control board used in DC chopping speed control system diagram
| The above-mentioned excellent performance of the IGC2.7 IGBT chopper control board makes it convenient to drive power IGBTs with a capacity of 600A or less, and it is now used for DC chopping Take the speed control system as an example to illustrate its application wiring. The IGBT used in this system utilizes its own built-in driven IGBT short circuit, under-saturation, gate voltage drop and soft turn-off protection, as well as external load over-current protection, and its current sampling signal is applied by Hall The current sensor HL comes.