阅读说明：本技术 一种48v永磁同步电机驱动器过压保护系统 (48V PMSM driver overvoltage protection system ) 是由 韩浩 廖昕湲 黄建刚 袁宝成 于 2020-11-24 设计创作，主要内容包括：本发明涉及过压保护技术领域,具体地说是一种48V永磁同步电机驱动器过压保护系统,包括12V电平端器件、ASC电路模块、上MOS管、下MOS管、母线过压比较器、48V供电电源、12V供电电源。本发明同现有技术相比,通过母线过压比较器、ASC电路模块、数值可编程逻辑器件的组合,在多种失效工况下,实现mos管的开通或关断,使电机进入三相短路状态,降低电机反电势,保证高压安全；在驱动电路失效时,能通过ASC电路径控制上MOS管和下MOS管的状态,保持过压保护功能,提高了驱动器的过压安全等级；采用硬件逻辑关断,将过压保护的响应时间提高至us级别,以应对48V永磁同步电机反电势上升斜率过快的问题；采用双电源供电,具备冗余功能。(The invention relates to the technical field of overvoltage protection, in particular to an overvoltage protection system of a 48V permanent magnet synchronous motor driver, which comprises a 12V level end device, an ASC circuit module, an upper MOS tube, a lower MOS tube, a bus overvoltage comparator, a 48V power supply and a 12V power supply. Compared with the prior art, the on-off switching method has the advantages that through the combination of the bus overvoltage comparator, the ASC circuit module and the numerical programmable logic device, the mos tube is switched on or off under various failure working conditions, so that the motor enters a three-phase short circuit state, the counter potential of the motor is reduced, and high-voltage safety is guaranteed; when the drive circuit fails, the states of the upper MOS tube and the lower MOS tube can be controlled through the ASC electrical path, the overvoltage protection function is kept, and the overvoltage safety level of the driver is improved; hardware logic is adopted for switching off, the response time of overvoltage protection is improved to us level, and the problem that the rising slope of the back electromotive force of the 48V permanent magnet synchronous motor is too fast is solved; and the dual power supplies are adopted for power supply, so that the redundant function is achieved.)

1. The utility model provides a 48V PMSM driver overvoltage protection system, includes 12V level end device, ASC circuit module (4), goes up MOS pipe (5), MOS pipe (6), generating line overvoltage comparator (7), 48V power supply, 12V power supply down, its characterized in that: the driving signal three ends of the 12V level end device are connected with the driving end of the upper MOS tube (5) and one end of a pull-down switch (S2) of the ASC circuit module (4), the driving signal four ends of the 12V level end device are connected with the driving end of the lower MOS tube (6) through the ASC circuit module (4), a bus overvoltage comparator (7) collects bus voltage of the 48V motor driver, fault signals are divided into three paths and fed back to the pull-down switch (S2) of the ASC circuit module (4), a switch (S1) and a digital programmable logic device (2) of the 12V level end device, the 12V level end device is powered by a 12V power supply, and the ASC circuit module (4) and the bus overvoltage comparator (7) are powered by a 48V power supply.

2. The overvoltage protection system for a 48V pm synchronous motor driver as claimed in claim 1, wherein: the ASC circuit module (4) comprises a diode (D1), a switch (S1), a pull-down switch (S2) and a pull-up resistor (R1), one end of the pull-down switch (S2) is connected with the three ends of a driving signal of a 12V-level end device, the other end of the pull-down switch (S2) is grounded, one end of a parallel structure of the switch (S1) and the diode (D1) is connected with the four ends of the driving signal of the 12V-level end device, the other end of the parallel structure of the switch (S1) and the diode (D1) is divided into two paths and is connected with the driving end of a lower MOS transistor (6) and one end of the pull-up resistor (R1), and the other end of the pull-up resistor (R1) is connected with a 48V power supply source.

3. The overvoltage protection system for a 48V pm synchronous motor driver as claimed in claim 1, wherein: the 12V level end device comprises an MCU (1), a digital programmable logic device (2) and a driver (3), wherein the MCU (1) sends a first driving signal to the digital programmable logic device (2), the digital programmable logic device (2) sends a second gate driving signal to the driver (3), and the driver (3) outputs a third driving signal for controlling an upper MOS (metal oxide semiconductor) tube (5) and a fourth driving signal for controlling a lower MOS tube (6).

4. The overvoltage protection system for a 48V pm synchronous motor driver as claimed in claim 3, wherein: the driver (3) is a MOSFET driver or an IGBT.

5. The overvoltage protection system for a 48V pm synchronous motor driver as claimed in claim 3, wherein: the power supply end of the digital programmable logic device (2) is connected with the 12V power supply through a logic device power supply module (8), and the power supply end of the driver (3) is connected with the 12V power supply through a driver power supply module (9).

6. The overvoltage protection system for a 48V pm synchronous motor driver as claimed in claim 1, wherein: the power supply end of the ASC circuit module (4) is connected with the 48V power supply through the ASC circuit power supply module (10), and the power supply end of the bus overvoltage comparator (7) is connected with the 48V power supply through the bus overvoltage comparison power supply module (11).

7. A 48V pm synchronous motor drive overvoltage protection system as claimed in claim 1 or 2 or 3 wherein: under the normal working state, the 48V power supply and the 12V power supply normally supply power, the switch (S1) is switched on, the pull-down switch (S2) is switched off, the drive signal three controls the upper MOS tube (5) to be switched on, the drive signal four controls the lower MOS tube (6) to be switched on, and the motor normally operates.

8. A 48V pm synchronous motor drive overvoltage protection system as claimed in claim 1 or 2 or 3 wherein: when a 12V level end device or a 12V power supply fails, the back electromotive force of the motor can be rapidly increased when the motor is in a high rotating speed state, a bus overvoltage comparator (7) is triggered, the bus overvoltage comparator (7) sends an overvoltage low-level fault signal to a pull-down switch (S2) and a switch (S1), the pull-down switch (S2) is firstly closed and shields a driving signal III, after an upper MOS (5) is completely switched off, the switch (S1) is then opened and shields a driving signal IV, the lower MOS (6) is switched on through a pull-up resistor (R1), the motor enters a three-phase short circuit state, and the situation that the back electromotive force of a 48V end is too high is prevented.

9. A 48V pm synchronous motor drive overvoltage protection system as claimed in claim 1 or 2 or 3 wherein: when the motor is in a high-rotation-speed power generation state and a relay at the 48V end fails and is disconnected, the bus voltage rises to trigger a bus overvoltage comparator (7), the bus overvoltage comparator (7) sends a fault signal to the digital programmable logic device (2), the pull-down switch (S2) and the switch (S1), after receiving the fault signal, the digital programmable logic device (2) latches the fault, and sends a PWM signal that the upper MOS tube is turned off and the lower MOS tube is turned on through a gate-level driving signal II; after receiving the fault signal, closing a pull-down switch (S2) and shielding a driving signal III, and turning off an upper MOS (metal oxide semiconductor) tube (5); the switch (S1) is turned off, the diode (D1) transmits a high-level signal of the driving signal four to the lower MOS tube (6), the lower MOS tube (6) is always in an on state, the motor enters a three-phase short-circuit state, and the reverse potential of the 48V end is prevented from being too high.

Technical Field

The invention relates to the technical field of overvoltage protection, in particular to an overvoltage protection system for a 48V permanent magnet synchronous motor driver.

Background

At present, the fuel consumption standard of passenger vehicles is more severe, and the emission standard of reducing the fuel consumption to 5L per hundred kilometers in 2020 is difficult to reduce by simply improving the fuel efficiency of an engine. The 48V micro-mixing system can realize higher oil saving rate with lower cost, and becomes a technical route with higher cost performance.

However, the maximum back electromotive force of the 48V permanent magnet synchronous motor is higher than the 60V safety voltage, and the back electromotive force at high rotating speed is generally higher than the withstand voltage of the power device, so that the power device is easily broken down to cause the torque runaway of the motor. Under high rotating speed, the rising slope of the back electromotive force of the 48V permanent magnet synchronous motor can reach 2-4V/us, and the traditional MCU for receiving and processing overvoltage faults obviously cannot meet the harsh time requirement. And with the improvement of the requirement of functional safety level, the single overvoltage fault processing path can not cover extreme failure working conditions such as MCU, CPLD random failure, software failure and the like.

In a high-performance ultra-high-speed permanent magnet synchronous motor control system based on an ARM and an FPGA, the publication number CN110266218A discloses bus overvoltage protection, whether bus voltage is overvoltage is judged through a comparison circuit, an overvoltage signal is sent to a control unit through a gate circuit, and the control unit judges the signal according to an algorithm and realizes software protection.

However, such an overvoltage protection system has the following problems for a 48V permanent magnet synchronous motor: 1) the voltage comparison circuit and the gate circuit are adopted to realize overvoltage judgment and overvoltage signal driving, but when the gate circuit fails, overvoltage signal driving cannot be realized, so that the protection system fails. 2) The back electromotive force rising slope of the 48V permanent magnet synchronous motor is very fast, the software protection response is in the ms level, and the protection cannot be carried out in time.

Therefore, an overvoltage protection system for a driver of a 48V permanent magnet synchronous motor needs to be designed, so that an overvoltage protection function can be kept when a driving circuit fails, and meanwhile, the response time of overvoltage protection is improved to the us level, so that the problem that the rising slope of the back electromotive force of the 48V permanent magnet synchronous motor is too fast is solved, the function safety level of overvoltage of the driver is improved, and personal safety is guaranteed.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an overvoltage protection system for a 48V permanent magnet synchronous motor driver, which can keep an overvoltage protection function when a driving circuit fails, and simultaneously improve the response time of overvoltage protection to us level so as to solve the problem that the back electromotive force rising slope of the 48V permanent magnet synchronous motor is too fast, improve the functional safety level of overvoltage of the driver and ensure personal safety.

In order to achieve the aim, the invention discloses an overvoltage protection system of a 48V permanent magnet synchronous motor driver, which comprises a 12V level end device, an ASC circuit module, an upper MOS tube, a lower MOS tube, a bus overvoltage comparator, a 48V power supply and a 12V power supply, wherein the 3 end of a driving signal of the 12V level end device is connected with the driving end of the upper MOS tube and one end of a pull-down switch of the ASC circuit module, the four ends of the driving signal of the 12V level end device are connected with the driving end of the lower MOS tube by the ASC circuit module, the bus overvoltage comparator acquires the bus voltage of the 48V motor driver, and the fault signal is divided into three paths and respectively fed back to a pull-down switch and a switch of the ASC circuit module and a digital programmable logic device of a 12V level end device, the 12V level end device is powered by a 12V power supply, and the ASC circuit module and the bus overvoltage comparator are powered by a 48V power supply.

Optionally, the ASC circuit module includes a diode, a switch, a pull-down switch, and a pull-up resistor, one end of the pull-down switch is connected to the end 3 of the driving signal of the 12V level end device, the other end of the pull-down switch is grounded, one end of the switch and diode parallel structure is connected to the four ends of the driving signal of the 12V level end device, the other end of the switch and diode parallel structure is divided into two paths and respectively connected to the driving end of the lower MOS transistor and one end of the pull-up resistor, and the other end of the pull-up resistor is connected to the 48V power supply.

Optionally, the 12V level end device includes an MCU, a digital programmable logic device, and a driver, where the MCU sends the first driving signal to the digital programmable logic device, the digital programmable logic device sends the second gate-level driving signal to the driver, and the driver outputs a driving signal 3 for controlling the upper MOS transistor and a driving signal four for controlling the lower MOS transistor.

Optionally, the driver is a MOSFET driver or an IGBT.

Optionally, the power supply end of the digital programmable logic device is connected with the 12V power supply by the logic device power supply module, and the power supply end of the driver is connected with the 12V power supply by the driver power supply module.

Optionally, a power end of the ASC circuit module is connected to the 48V power supply through the ASC circuit power supply module, and a power end of the bus overvoltage comparator is connected to the 48V power supply through the bus overvoltage comparison power supply module.

Under the normal working state, the 48V power supply and the 12V power supply normally supply power, the switch is switched on, the pull-down switch is switched off, the drive signal 3 controls the upper MOS tube to be switched on, the drive signal four controls the lower MOS tube to be switched on, and the motor normally operates.

When a 12V level end device or a 12V power supply fails, the back electromotive force of the motor is rapidly increased when the motor is in a high rotating speed state, a bus overvoltage comparator is triggered, the bus overvoltage comparator sends an overvoltage low-level fault signal to a pull-down switch and a switch, the pull-down switch is firstly closed and shields a driving signal 3, after an upper MOS tube is completely closed, the switch is then disconnected and a driving signal is shielded, the lower MOS tube is switched on through a pull-up resistor, the motor enters a three-phase short circuit state, and the back electromotive force of a 48V end is prevented from being too high.

When the motor is in a high-rotation-speed power generation state and the relay at the 48V end fails and is disconnected, the bus voltage rises to trigger the bus overvoltage comparator, the bus overvoltage comparator sends a fault signal to the digital programmable logic device, the pull-down switch and the switch, and after the fault signal is received, the digital programmable logic device latches the fault and sends a PWM signal for switching off the upper MOS tube and switching on the lower MOS tube through the gate-level driving signal II; after receiving the fault signal, the pull-down switch is closed and shields the driving signal 3, and the upper MOS tube is switched off; and the switch is turned off, the diode transmits a high-level signal of the driving signal IV to the lower MOS tube, the lower MOS tube is always in an on state, and the motor enters a three-phase short-circuit state to prevent the counter potential of the 48V end from being too high.

Compared with the prior art, the on-off switching method has the advantages that through the combination of the bus overvoltage comparator, the ASC circuit module and the numerical programmable logic device, the on-off of the mos tube is realized under various failure working conditions such as 12V power failure, 48V power failure, MCU failure and digital programmable logic device failure, so that the motor enters a three-phase short circuit state, the back electromotive force of the motor is reduced, and the high-voltage safety is ensured; when the drive circuit fails, the states of the upper MOS tube and the lower MOS tube can be controlled through the ASC electrical path, the overvoltage protection function is kept, and the overvoltage safety level of the driver is improved; hardware logic is adopted for switching off, the response time of overvoltage protection is improved to us level, and the problem that the rising slope of the back electromotive force of the 48V permanent magnet synchronous motor is too fast is solved; and the dual power supplies are adopted for power supply, so that the redundant function is achieved.

Drawings

FIG. 1 is a block diagram of the system of the present invention.

Referring to fig. 1, 1 is an MCU, 2 is a digital programmable logic device, 3 is a driver, 4 is an ASC circuit module, 5 is an upper MOS transistor, 6 is a lower MOS transistor, 7 is a bus overvoltage comparator, 8 is a logic device power supply module, 9 is a driver power supply module, 10 is an ASC circuit power supply module, and 11 is a bus overvoltage comparison power supply module.

Detailed Description

The invention will now be further described with reference to the accompanying drawings.

Referring to fig. 1, the invention is a 48V permanent magnet synchronous motor driver overvoltage protection system, which comprises a 12V level end device, an ASC circuit module 4, an upper MOS transistor 5, a lower MOS transistor 6, a bus overvoltage comparator 7, a 48V power supply, and a 12V power supply, wherein a driving signal 3 end of the 12V level end device is connected with a driving end of the upper MOS transistor 5 and one end of a pull-down switch S2 of the ASC circuit module 4, four driving signal ends of the 12V level end device are connected with the driving end of the lower MOS transistor 6 by the ASC circuit module 4, the bus overvoltage comparator 7 collects bus voltage of the 48V motor driver, and the fault signal is divided into three paths and fed back to the pull-down switch S2, the switch S1 and the digital programmable logic device 2 of the 12V level end device of the ASC circuit module 4 respectively, the 12V level end device is powered by a 12V power supply, and the ASC circuit module 4 and the bus overvoltage comparator 7 are powered by a 48V power supply.

The ASC circuit module 4 comprises a diode D1, a switch S1, a pull-down switch S2 and a pull-up resistor R1, one end of the pull-down switch S2 is connected with the 3 end of a driving signal of a 12V flat-end device, the other end of the pull-down switch S2 is grounded, one end of a parallel structure of the switch S1 and the diode D1 is connected with the four ends of the driving signal of the 12V flat-end device, the other end of the parallel structure of the switch S1 and the diode D1 is divided into two paths and connected with the driving end of the lower MOS transistor 6 and one end of the pull-up resistor R1, and the other end of the pull-up resistor R1 is connected with a 48V power.

The 12V level end device comprises an MCU1, a digital programmable logic device 2 and a driver 3, wherein the MCU1 sends a first driving signal to the digital programmable logic device 2, the digital programmable logic device 2 sends a second gate driving signal to the driver 3, and the driver 3 outputs a driving signal 3 for controlling an upper MOS tube 5 and a driving signal four for controlling a lower MOS tube 6.

The power supply end of the digital programmable logic device 2 is connected with a 12V power supply through a logic device power supply module 8, and the power supply end of the driver 3 is connected with the 12V power supply through a driver power supply module 9. The power supply end of the ASC circuit module 4 is connected with the 48V power supply through the ASC circuit power supply module 10, and the power supply end of the bus overvoltage comparator 7 is connected with the 48V power supply through the bus overvoltage comparison power supply module 11. The invention adopts double power supplies for power supply and has a redundancy function.

The driver 3 is a MOSFET driver or an IGBT.

In a normal working state, the 48V power supply and the 12V power supply normally supply power, the switch S1 is switched on, the pull-down switch S2 is switched off, the drive signal 3 controls the upper MOS transistor 5 to be switched on, the drive signal four controls the lower MOS transistor 6 to be switched on, and the motor normally operates.

When 12V level end device failure or 12V power supply failure such as MCU1 software runaway or hardware random failure, digital programmable logic device 2 hardware random failure, driver 3 failure and the like occurs, the motor is in a high rotating speed state to cause the back electromotive force of the motor to rise rapidly, a bus overvoltage comparator 7 is triggered, the bus overvoltage comparator 7 sends an overvoltage low level fault signal to a pull-down switch S2 and a switch S1, the pull-down switch S2 is closed firstly and shields a driving signal 3, after an MOS (metal oxide semiconductor) transistor 5 is completely closed, the switch S1 is opened and shields a driving signal IV, a lower MOS transistor 6 is opened through a pull-up resistor R1, the motor enters a three-phase short circuit state, and the back electromotive force of a 48V end is prevented from being too high.

When a motor is in a high-speed power generation state and a relay at a 48V end is in failure disconnection, the voltage of a bus rises to trigger a bus overvoltage comparator 7, the bus overvoltage comparator 7 sends a fault signal to a digital programmable logic device 2, a pull-down switch S2 and a switch S1, after the fault signal is received, the digital programmable logic device 2 latches the fault and sends a PWM (pulse width modulation) signal that an upper MOS (metal oxide semiconductor) tube is turned off and a lower MOS tube is turned on through a gate-level driving signal II; after receiving the fault signal, the pull-down switch S2 is closed and shields the driving signal 3, and the upper MOS tube 5 is turned off; the switch S1 is turned off, the diode D1 transmits a high level signal of the driving signal IV to the lower MOS tube 6, the lower MOS tube 6 is always in an on state, the motor enters a three-phase short circuit state, the counter potential of the 48V end is prevented from being too high, and high-voltage safety is realized. At this time, a high-voltage overvoltage fault occurs, so that the low-voltage system can normally work, and the ASC circuit module 4 also participates in protection work. The ASC circuit module 4 is independent of a gate-level driving circuit of a 12V level end device, and can control the states of the upper MOS transistor 5 and the lower MOS transistor 6 through an independent path of the ASC circuit module 4 after the gate-level driving circuit fails.

The invention adopts the bus overvoltage comparator 7, the ASC circuit module 4 and the numerical value programmable logic device 2 to realize shielding or connection of driving signals, thereby realizing the connection or disconnection of the upper MOS tube 5 and the lower MOS tube 6, controlling the motor to enter a three-phase short circuit state and realizing protection. The hardware logic is switched off, the response time is in the us level, and the problem that the rising slope of the back electromotive force of the 48V permanent magnet synchronous motor is too fast can be solved.

According to the invention, through the combination of the bus overvoltage comparator 7, the ASC circuit module 4 and the numerical programmable logic device 2, under various failure working conditions such as 12V power failure, 48V power failure, MCU failure, digital programmable logic device failure and the like, the mos tube is switched on or off, so that the motor enters a three-phase short circuit state, the counter potential of the motor is reduced, and the high-voltage safety is ensured; when the drive circuit fails, the states of the upper MOS tube and the lower MOS tube can be controlled through the ASC electrical path, the overvoltage protection function is kept, and the overvoltage safety level of the driver is improved; hardware logic is adopted for switching off, the response time of overvoltage protection is improved to us level, and the problem that the rising slope of the back electromotive force of the 48V permanent magnet synchronous motor is too fast is solved; and the dual power supplies are adopted for power supply, so that the redundant function is achieved.