0 Introduction
inverter has been widely used in many areas of technology in AC electric drive, UPS, the main circuit switching devices often used the IGBT or MOSF, ET, such as full-controlled device, the switching action of such devices need to rely on a separate drive circuit and drive circuit of the power supply are isolated from each other (such as single-phase bridge inverter main circuit 3 group of independent power supply, three-phase bridge inverter main circuit needs 4 independent power supply), which will undoubtedly increase the auxiliary power supply design difficulties and cost, but also complicated, reduce the reliability of the inverter drive circuit. Using such integrated drive circuit EXB840 special thick film chip simplifies the design of the drive circuit, each driver chips still need an isolated power supply, and each chip can only be to drive a power switching device, the application is still inconvenient. Only one power supply while the dedicated driver chips produced by the United States International Rectifier IR2132 three-phase bridge inverter circuit to drive six power switching devices, the entire driver circuit is simple and reliable.http://www.gridtieinverter.de/
1 IR2132 driver chip features
IR2132 can be used to drive the bus voltage is not higher than 600 V circuit power MOS-gated device, its maximum forward peak output drive current of 250 mA and reverse peak drive current of 500 mA. The design of its internal overcurrent, overvoltage and undervoltage protection, blockade, and indicates that the network, so users can easily be used to protect the power MOS gate drive tube, coupled with the clever use of the internal bootstrap technique so that it can be used for high-pressure system It can also be on the door of the two power devices of the same bridge arm gate drive signal to produce interlock delay time O.8μs. A wide range of its own work and the power supply voltage (3 to 20 V), in its internal design of the current through the power device is driven by a linear relationship between current amplifier circuit design also ensures that the internal 3 the high side driver and low-side of the channel of the drive can be used alone, but also its internal use only three low-side driver, and the input signal and the TTL and CMOS level compatible. IR2132 pin shown in Figure 1. VBl ~ VB3 is suspended power supply ground terminal, by a bootstrap capacitor 3 on bridge arm power tube drive internal suspension power, VSl ~ VS3 is suspended corresponding power ground terminal.
HINl ~ HIN3, LINl ~ LIN3 inverter bridge arm and lower leg drive signal input, active low.
ITRIP the overcurrent signal detection input, input current signal to complete stream or direct protection.
CA CA0, VSO to the inverting terminal of the internal amplifier, the output terminal and the noninverting terminal, can be used to complete the current signal detection.
H01 ~ H03, L01 ~ L03 arm power switching devices of the upper and lower bridge of the inverter drive signal output terminal.
FAULT overcurrent direct short circuit, overvoltage, undervoltage protection, the output of the end provide a fault indication signal protection. Inside the chip is an open-drain output, active low.
VCC, VSS chip power supply connection end, VCC connected to the positive supply and VSS power supply ground.
2 IR2132 internal structure and its working principle
IR2132 internal structure shown in Figure 2, its internal integration of a current comparator (Current Comparator), a current amplifier (Current Amp) own work power supply under-voltage detector (Under Voltage Detector ), a fault processing unit (Fault Logic) and a clear the blockade logic unit (Clear Logic). In addition to the above, its internal integrated three input signal processor (Input Signal Generator), two pulse processing and level shifter (Pulse Generator Level Shifter), the upper bridge arm side power transistor drive signal latch (Latch), 3 on the arm side power transistor drive signal and undervoltage detector (Under Voltage Detector) and six low output impedance MOS power transistor drive (Driver) and one or gates,Grid tie inverter.
directly sent to the driving power, the 6-channel of the input drive signal by the input signal processor normal working
, after processing into a 6-channel output pulse, the drive signal of the lower arm of the power tube L1 to L3 via the output drive amplifier devices. And driving the upper bridge arm of the power tube signals H1 to H3 first been integrated in the IR2132 internal three pulse processor and level shifter in the bootstrap circuit potential conversion, a drive pulse potential suspension was changed to 3-way, and then by corresponding output latch latches by strict driving pulse or not after the test,power inverter, the power tube amplifier is driven only added to the output drive. Once outside the current flow, or through, the signal sent by the current detection unit higher than 0.5 V, the IR2132 internal current comparator quickly flip prompted low level the fault logic unit output, an input pulse signal block 3-way the output of the processor, so the IR2132 output of all low, protect the power tube; same time the IR2132's FAULT foot fault indication is given. Similarly, if the occurrence of IR2132 power undervoltage, undervoltage detector quickly flip will carry out similar actions. Failure after failure within the IR2132 output logic unit will maintain a fault lockout state. Until the the fault clearing input high signal input terminal LINl ~ LIN3 before lift the the failure lockout state.
driver on bridge arm power tube
IR2132 bootstrap supply voltage is low, the rapid action of the drive signal detector circuit, the blockade of the output to avoid power devices due to lack of drive signal damage. When two of the power devices of the same bridge arm of the inverter input signal is high at the same time, the IR2132 output of 2-way gate drive signals to all low level, thereby reliably avoid bridge arm occurs.
3 IR2132 inverter circuit structure
3.1 control circuit
uses a novel prefabricated phase PWM wave digital control programs, SPWM pulse corresponding to the inverter 6 of the switching state of the switching tube and a modulation ratio, the starting point is an EP-ROM to store this 6 switch, switch status, preset by a variety of ways within the EPROM common is first calculated, corresponding to the different fundamental frequency, converted to the value corresponding to the pulse width is calculated according to certain rules, stored in EPROM, the EPROM output IR2132's HINl to HIN3, LINl ~ LIN3 connected. Phase difference between the same leg switch 120 °, the complementary conduction switch under the same bridge arm and there is a dead zone. SPWM wave generating circuit shown in Figure 3.
3.2 driver circuit
IR2132 chip driving inverter power tube, the basic main circuit without changing, still using a typical three-phase voltage-type inverter circuit, for ease of a bridge driver of the IR2132, drawn in Figure 4 schematic circuit diagram of the arm. C1 is the bootstrap capacitor the suspension power stored energy, for the power of the upper bridge arm tube driven VD1 role is to prevent the upper bridge arm conduction when the DC voltage bus voltage is applied to the IR2132 power in the device damage, so VD1 reverse voltage should be enough, of course, due to the VD1 C1 series, in order to meet the requirements of the main circuit power switching frequency, VD1 be elected fast recovery diode. R1 and R2 are the IGBT gate drive resistors can be used 10 to tens of ohms. R3 and R4 overcurrent detection circuit, wherein R3 is an over-current sampling resistor, R4 is the partial pressure of adjustable resistance. The IR2132's HINl to HIN3 LINl ~~ LIN3 as power tube input drive signal SPWM wave generation circuit EPROM connected. Its capacity depends on the switching frequency of the driving power of the device, the duty cycle and the charging circuit resistance, the need to ensure that the capacitor is charged to a sufficient voltage and the discharge voltage not less than its ends when the undervoltage protection action value, when the switch is driven frequency greater than 5 kHz, the capacitance value of not less than 0.1μF, and ceramic capacitors.
4 Conclusion
IR2132 devices to achieve a single-chip power supply three-phase inverter drive, reasonably select float capacitance, the drive circuit is very reliable, it not only makes the simple circuit structure, and improve the reliability, and can be reliably achieve short circuit, overcurrent, undervoltage and overvoltage fault protection.
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