阅读说明：本技术 一种三相逆变器桥臂精确电流检测的保护设计 (Protection design for accurate current detection of three-phase inverter bridge arm ) 是由 颜景斌 刘清岚 李瑞松 于 2019-12-05 设计创作，主要内容包括：本发明涉及三相电能变换领域，具体涉及一种三相逆变器桥臂精确电流检测的保护设计，一种三相逆变器桥臂精确电流检测的保护设计包括栅极驱动器、IGBT模块、电动机、四通道运算放大器、单通道运算放大器、微功耗比较器、温度传感器、六路缓冲及线性驱动器、微控制器、电阻R1、R2、R3、电容C1和DC/DC降压转换器，此参考设计展示了摆幅响应趋稳时间接近1μs、准确度误差小于1%的逆变器桥臂电流感应；即使附近有高功率IGBT开关，此设计也可展现出优异的噪声抑制性能。(The invention relates to the field of three-phase electric energy conversion, in particular to a protection design for accurate current detection of a three-phase inverter bridge arm, which comprises a gate driver, an IGBT module, a motor, a four-channel operational amplifier, a single-channel operational amplifier, a micro-power consumption comparator, a temperature sensor, a six-channel buffer and linear driver, a microcontroller, resistors R1, R2, R3, a capacitor C1 and a DC/DC buck converter, wherein the reference design shows that the oscillation amplitude response stability approaching time is close to 1 mu s, and the accuracy error is less than 1% of inverter bridge arm current induction; this design can exhibit excellent noise rejection performance even with high power IGBT switches in the vicinity.)

1. The protection design for accurate current detection of the bridge arm of the three-phase inverter is characterized in that: the device comprises a gate driver, an IGBT module, a motor, a four-channel operational amplifier, a single-channel operational amplifier, a micro power consumption comparator, a temperature sensor, a six-path buffer and linear driver, a microcontroller, resistors R1, R2, R3, a capacitor C1 and a DC/DC buck converter, wherein the gate driver and the IGBT module are connected together; the output end of the IGBT module is connected with a motor; the capacitor C1 is connected between the positive electrode and the negative electrode of the power supply; the R1, the R2 and the R3 are respectively connected with three lower bridge arms of the IGBT module; the input end of the four-channel operational amplifier is connected to two ends of the resistor; the output end of the four-channel operational amplifier is connected with the microcontroller; the input end of the micro-power consumption comparator is connected with a four-channel operational amplifier; the output end of the micro-power consumption operational amplifier is connected with six paths of buffer and linear driver OE ports; the PWM wave fed back by the microcontroller is input into a circuit buffer and linear driver; the temperature sensor is connected with a single-channel operational amplifier; the output end of the single-channel operational amplifier is connected with the microcontroller; the DC/DC buck converter is connected with the microcontroller.

2. The protection design for accurate current detection of the bridge arm of the three-phase inverter according to claim 1, is characterized in that: the gate driver adopts UCC 27712; the IGBT module adopts six IGBTs to carry out half-bridge connection.

3. The protection design for accurate current detection of the bridge arm of the three-phase inverter according to claim 1, is characterized in that: the motor adopts a permanent magnet synchronous motor; the four-channel operational amplifier adopts TLV 9064.

4. The protection design for accurate current detection of the bridge arm of the three-phase inverter according to claim 1, is characterized in that: the single-channel operational amplifier adopts TLV 9001; the micro power comparator adopts TLV 1701.

5. The protection design for accurate current detection of the bridge arm of the three-phase inverter according to claim 1, is characterized in that: the temperature sensor employs a R63 (10 k Ω) and a resistor R74 (100 Ω).

6. The protection design for accurate current detection of the bridge arm of the three-phase inverter according to claim 1, is characterized in that: the six-path buffer and linear driver adopts SN74AHC 367; the microcontroller adopts TMS320F 28027.

7. The protection design for accurate current detection of the bridge arm of the three-phase inverter according to claim 1, is characterized in that: the DC/DC buck converter described employs the TPS 54202.

Technical Field

The invention relates to the field of three-phase electric energy conversion, in particular to a protection design for accurate current detection of a three-phase inverter bridge arm.

Technical Field

The inversion technology is a technology for converting direct current converted from new energy such as solar energy into alternating current, and along with the rapid development of power electronic technology, the inversion technology is widely applied to various industries, and particularly along with the increasing shortage of main energy such as petroleum, coal, natural gas and the like, the development and utilization of new energy are more and more emphasized by people.

The inverter is an important component of the whole current transformation, and the quality of the performance of the inverter directly influences the quality of electric energy; delays or slow responses in current sensing may result in erroneous current estimates, leading to distortion of the current waveform, resulting in poor conversion efficiency and noise generation; therefore, it is necessary to improve the accuracy of inverter current induction and to improve the noise suppression capability.

Disclosure of Invention

The invention aims to provide a protection design for accurate current detection of a three-phase inverter bridge arm, the inverter can accurately induce current and has excellent noise suppression performance and very wide application prospect.

The purpose of the invention is realized by the following technical scheme: the protection design for the accurate current detection of the bridge arm of the three-phase inverter comprises a gate driver, an IGBT module, a motor, a four-channel operational amplifier, a single-channel operational amplifier, a micro-power consumption comparator, a temperature sensor, a six-channel buffer and linear driver, a microcontroller, resistors R1, R2, R3, a capacitor C1 and a DC/DC buck converter, wherein the gate driver and the IGBT module are connected together; the output end of the IGBT module is connected with a motor; the capacitor C1 is connected between the positive electrode and the negative electrode of the power supply; the R1, the R2 and the R3 are respectively connected with three lower bridge arms of the IGBT module; the input end of the four-channel operational amplifier is connected to two ends of the resistor; the output end of the four-channel operational amplifier is connected with the microcontroller; the input end of the micro-power consumption comparator is connected with a four-channel operational amplifier; the output end of the micro-power consumption operational amplifier is connected with six paths of buffer and linear driver OE ports; the PWM wave fed back by the microcontroller is input into a circuit buffer and linear driver; the temperature sensor is connected with a single-channel operational amplifier; the output end of the single-channel operational amplifier is connected with the microcontroller; the DC/DC buck converter is connected with the microcontroller.

As a further optimization of the invention, the gate driver of the protection design for accurate current detection of the three-phase inverter bridge arm of the invention adopts UCC27712, which is a 620V high-side and low-side gate driver, aiming at driving power MOSFET or IGBT; the device has the characteristics of fast propagation delay, good delay matching among channels and the like.

As further optimization of the invention, the IGBT module is in half-bridge connection by adopting six IGBTs, the direct current side of the IGBT module uses a capacitor C1, and each bridge arm consists of a diode and an IGBT.

As further optimization of the invention, the motor is a permanent magnet synchronous motor according to the protection design for accurate current detection of the three-phase inverter bridge arm.

As further optimization of the invention, the four-channel operational amplifier adopted by the protection design for the accurate current detection of the three-phase inverter bridge arm adopts TLV9064, has sufficient gain bandwidth and conversion rate, RRIO capability, good CMRR and PSRR, good EMI and RFI inhibition, low bias voltage and input bias current and stable capacitive load drive, and is suitable for application occasions requiring low-voltage operation, small occupied space and high capacitive load drive.

As further optimization of the invention, the single-channel operational amplifier of the protection design for accurate current detection of the three-phase inverter bridge arm adopts TLV9001, and has rail-to-rail input and output swing capacity; these operational amplifiers provide a cost effective solution for space-limited applications; its resistive open loop output impedance makes higher capacitive loads easier to stabilize.

As a further optimization of the invention, the micro-power consumption comparator of the protection design for accurate current detection of the three-phase inverter bridge arm adopts TLV1701, and the device provides a wide power supply range, rail-to-rail input, low quiescent current and low propagation delay.

As a further optimization of the invention, the temperature sensor of the protection design for accurate current detection of the three-phase inverter bridge arm adopts R63 (10 k omega) and a resistor R74 (100 omega).

As a further optimization of the invention, the six-way buffer and linear driver of the protection design for accurate current detection of the three-phase inverter bridge arm adopts SN74AHC367 which is used for VCC operation from 2V to 5.5V, and the device is specially designed for improving the performance and the density of a microcontroller.

As a further optimization of the present invention, the microcontroller according to the protection design for accurate current detection of the three-phase inverter leg of the present invention employs TMS320F28027, which provides the capability of a C28x core, and in combination with highly integrated control peripherals in a low pin count device, can directly route control PWM output, ADC conversion is from 0V to a fixed full range of 3.3V, and the ADC interface has been optimized to reduce overhead and delay.

As further optimization of the invention, the TPS54202 is adopted in the DC/DC buck converter for the protection design of the accurate current detection of the three-phase inverter bridge arm, and the DC/DC buck converter is a small-sized DC/DC module with high efficiency and low EMI (electro-magnetic interference), so that the size and the cost are saved, and a radiator is not needed; using the same input current, the TPS54202 as a power converter can provide higher output current and lower power consumption at full load, low load and standby operation.

The invention has the beneficial effects that: the inverter has low cost and high accuracy, the stability approaching time of current induction is less than 1.25 mu s, the calibration accuracy is less than 1 percent, and the accurate current induction can be realized; the TMS320F28027 is adopted by the microcontroller, the microcontroller is provided with an ADC single chip microcomputer with good power supply noise suppression, and even if a high-power IGBT switch is arranged nearby, the design can show excellent noise suppression performance; according to the design, overcurrent protection is fully realized through hardware, and the total response time is lower than 1.5 microseconds; the reference design is applicable to compressors; the power stage of the inverter may operate at up to 2kW of power.

Drawings

FIG. 1 is a schematic structural diagram of a protection design for accurate current detection of a three-phase inverter bridge arm according to the present invention;

fig. 2 is a schematic structural diagram of a temperature sensor for protection design of accurate current detection of a three-phase inverter bridge arm according to the present invention.

Detailed Description

The embodiment is described with reference to fig. 1 and 2, and the protection design for accurate current detection of the three-phase inverter bridge arm according to the embodiment includes a gate driver, an IGBT module, a motor, a four-channel operational amplifier, a single-channel operational amplifier, a micro-power comparator, a temperature sensor, a six-channel buffer and linear driver, a microcontroller, resistors R1, R2, R3, a capacitor C1, and a DC/DC buck converter.

The temperature sensor described therein uses an NTC resistor, specifically an R63 (10 k Ω) to 3.3V and a resistor R74 (100 Ω) ground as shown in fig. 2, with the voltage across the NTC connected as an input to the op-amp TLV 9001.

The gate driver adopts UCC27712, which is a 620V high-side and low-side gate driver, and aims to drive the IGBT module; it includes the protection function, when the input keeps the opening state or when not meeting the minimum input pulse width standard, the output keeps the low level, interlock and dead zone function prevent from opening two outputs at the same time, it adopts the latest high-voltage apparatus technology, it has good noise and transient immunity, including the input end is great to the negative voltage tolerance, high dV/dt tolerance, greater Negative Transient Safe Operating Area (NTSOA) and interlock on the switch node; the device consists of a terrestrial reference channel (LO) and a float channel (HO) that is used to guide or isolate the power supply.

The DC/DC buck converter described therein employs the TPS54202, which is connected to the microcontroller and provides it with a voltage of 3.3V, as a buck converter, which can provide higher output current and lower power consumption at full load, low load and standby operation.

The four-channel operational amplifier adopts TLV9064, the input end of the four-channel operational amplifier is connected with an IGBT module, the output end of the four-channel operational amplifier is connected with a microcontroller and a micro-power consumption comparator, the four-channel operational amplifier has rail-to-rail input and output swing capacity, low input offset voltage and an internal RFI and EMI filter, and the four-channel operational amplifier is used for amplifying current output by an inverter.

The micro power consumption comparator adopts TLV1701, the input end of the micro power consumption comparator is connected with a four-channel operational amplifier, and the output end of the micro power consumption comparator is connected with a six-path buffer and linear driver; the comparator does not generate output phase reversal when the over-driving input and the internal hysteresis occur; it is well suited for precision voltage monitoring in harsh, noisy environments where slow input signals can be converted to noiseless digital outputs.

The transient response of the four-channel operational amplifier is evaluated by the voltage step change on the parallel resistor, the step change of the induced voltage is generated by a corresponding IGBT switch connected with the motor, so that the winding current flows through the induced resistor; the shunt resistor is easy to generate voltage oscillation, and the input filter of the amplifier and the internal EMI filter of the amplifier are beneficial to eliminating high-frequency oscillation on the parallel resistor; the full-swing transient response stability time of the current sensing amplifier is 1.25 us; the high 10mhz GBW and high rotation rate of the TLV9064 help to achieve faster settling time, the circuit uses one channel of the TLV9064 as a comparator, the TLV1701 as another comparator, and the output signal of the over-current protection circuit is connected to a six-way buffer and linear driver; upon an overcurrent event, the output signal will be pulled up and disable the line driver output, and thus the SVPWM signal will be disabled at the input of gate driver UCC 27712; therefore, the whole protection process is realized by hardware and has very fast response time.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.