An intelligent protection circuit suitable for high-voltage and high-power electric rudder system

Abstract

The present invention relates to an intelligent protection circuit suitable for a high-voltage and high-power electric rudder system, comprising: an SVPWM multi-channel processing module, a fast comparison isolation module and an intelligent protection integrated logic module, adopting a multi-channel integrated level conversion circuit, a buffer circuit with strong driving capability and a micro-sized high-speed photoelectric isolation circuit, thereby enhancing the dynamic response speed and anti-interference capability of the rudder system, solving the logic defects and insufficient dynamic response of the system control existing in a single protection mode; controlling the SVPWM output form after the two-phase current fast comparison current limiting output signal and the software current limiting control signal are subjected to logic synthesis operation and maintained by a trigger, thereby avoiding system misprotection, and having a high degree of circuit integration and intelligence, being easy to implement, having low cost and having strong adaptability.

Description

Technical Field

[0001] The invention relates to an intelligent protection circuit suitable for a high-voltage and high-power electric rudder system. Background Art

[0002] The performance and reliability of high-power electric rudder systems are closely related to the signal processing and isolation of the system, and the driving and protection strategies of power switch devices. The switching frequency of high-voltage and high-power IGBTs or IPMs is generally more than ten kHz or even higher. Due to the existence of stray inductances of different sizes in the circuit design, at high frequencies, the stable operation of the entire circuit will be greatly affected. A large surge voltage will be generated at the moment the power device is turned off, and a recovery surge voltage will be generated. The existence of the shutdown surge voltage and the recovery surge voltage will affect the normal operation of the IGBT or IPM, such as increased switching losses, excessive operating temperatures, and even damage; at the same time, the high current output of the system is prone to frequent breakdown of the power tube and electromagnetic interference, resulting in the system being unable to work properly, and may also cause excessive heating of the motor, resulting in a decrease in load capacity or even winding damage; in addition, high current output also places higher requirements on the system current margin, ground layout, and anti-interference ability. Therefore, the protection circuit is one of the key links in the high-power electric rudder system.

[0003] At present, the protection of high-voltage and high-power electric rudder systems adopts a single measure of bus current detection circuit or software current limiting protection. Due to the existence of shutdown surge voltage and recovery surge voltage and large current in the system, there is a large digital signal circuit interference and current and harmonic interference of the rudder system's strong electric analog signal in the bus current detection circuit signal, which will cause large logical defects in the system protection and cause false protection, which will cause unpredictable consequences for the rudder system. The current limiting parameters of the software current limiting protection method are difficult to define, the parameter range is wide and cannot effectively play a role in system protection, and the small parameter range has a greater adverse effect on the dynamic response performance of the rudder system. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an intelligent protection circuit suitable for high-voltage and high-power electric rudder systems, which solves the logical defects of the existing technical solutions due to system interference or the shortcomings of single measures, and at the same time can meet the requirements of high dynamic response performance of the system.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: an intelligent protection circuit adapted to a high-voltage and high-power electric rudder system, comprising: an SVPWM multi-channel processing module, which is used to control the six-channel PWM1~PWM6 output by the vector post-signal processor to be output to the buffer circuit D2A after level conversion by the integrated level conversion chip D1, and to be output to the photoelectric isolation circuit D3~D5 respectively after being passed through the pull-up resistors R1~R6 and the current limiting resistors R7~R12, and output;

[0006] The fast comparison isolation module is used to detect the output signal through the closed-loop Hall current sensor S1, and input it to the in-phase end of the voltage follower after processing through the T-type low-pass filter circuit composed of the high-precision sampling resistor RS1 and RT1, RT2, and CT3. The output signal I_A of the comparator is input to the high-speed photoelectric isolation circuit D6, and the A-phase current limiting protection signal 1A is output after isolation. The output signal I_B of the comparator is input to the high-speed photoelectric isolation circuit D6, and the B-phase current limiting protection signal 1B is output after isolation.

[0007] The intelligent protection integrated logic module is used to input the isolated output 1A, 1B current limiting protection signals and the software current limiting control signals 2A, 2B to the U16 chip for logical OR operation. The operation result is input to the clock end of the trigger U17A. When any signal input to the U17A trigger changes from a low level to a high level, the trigger U17A outputs a high level, controls the integrated level conversion chip D1 to stop outputting the SVPWM wave, and thereby stops the drive circuit from working.

[0008] Compared with the prior art, the present invention has the following beneficial technical effects: simple structure, including: SVPWM multi-channel processing module, fast comparison isolation module and intelligent protection integrated logic module, adopting multi-channel integrated level conversion circuit, buffer circuit with strong driving capability and miniature high-speed photoelectric isolation circuit, enhancing the dynamic response speed and anti-interference ability of the rudder system, solving the logical defects and insufficient dynamic response of system control existing in a single protection mode; controlling the SVPWM output form after the two-phase current fast comparison current limiting output signal and the software current limiting control signal are subjected to logical synthesis operation and maintained by a trigger to avoid system misprotection, the circuit has high integration and intelligence, is easy to implement, has low cost and strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a circuit diagram of an SVPWM multi-channel processing module of an intelligent protection circuit adapted to a high-voltage and high-power electric rudder system of the present invention;

[0010] Figure 2 It is a circuit diagram of a fast comparison isolation module of an intelligent protection circuit adapted to a high-voltage and high-power electric rudder system of the present invention;

[0011] Figure 3 It is a circuit diagram of an intelligent protection integrated logic module of an intelligent protection circuit adapted to a high-voltage and high-power electric rudder system of the present invention. DETAILED DESCRIPTION

[0012] The present invention is further described in detail below through specific implementation examples, but these implementation examples are only for illustration and do not limit the scope of the present invention.

[0013] Please refer to Figure 1 to Figure 3 , the intelligent protection circuit adapted to the high-voltage and high-power electric rudder system of the present invention comprises: an SVPWM multi-channel processing module, which is used to control the six-channel PWM1~PWM6 output by the vector post-signal processor to be output to the buffer circuit D2A after level conversion by the integrated level conversion chip D1, and to be output to the photoelectric isolation circuit D3~D5 respectively after being pulled up by the resistors R1~R6 and the current limiting resistors R7~R12, and output;

[0014] The fast comparison isolation module is used to detect the output signal through the closed-loop Hall current sensor S1, and input it to the in-phase end of the voltage follower after processing through the T-type low-pass filter circuit composed of the high-precision sampling resistor RS1 and RT1, RT2, and CT3. The output signal I_A of the comparator is input to the high-speed photoelectric isolation circuit D6, and the A-phase current limiting protection signal 1A is output after isolation. The output signal I_B of the comparator is input to the high-speed photoelectric isolation circuit D6, and the B-phase current limiting protection signal 1B is output after isolation.

[0015] The intelligent protection integrated logic module is used to input the isolated output 1A, 1B current limiting protection signals and the software current limiting control signals 2A, 2B to the U16 chip for logical OR operation. The operation result is input to the clock end of the trigger U17A. When any signal input to the U17A trigger changes from a low level to a high level, the trigger U17A outputs a high level, controls the integrated level conversion chip D1 to stop outputting the SVPWM wave, and thereby stops the drive circuit from working.

[0016] In one embodiment, the SVPWM multi-channel processing module includes: an integrated level conversion chip D1, a high-speed CMOS enhanced drive type six Schmitt trigger D2A, and optoelectronic isolation circuits D3, D4, and D5, wherein pin 2 of D1 is connected to pin 1 of D2A, pin 3 of D1 is connected to pin 3 of D2A, pin 5 of D1 is connected to pin 5 of D2A, pin 6 of D1 is connected to pin 9 of D2A, pin 8 of D1 is connected to pin 13 of D2A, pin 9 of D1 is connected to pin 11 of D2A, pin 46 of D1 is connected to pin 7 of D3, pin 47 of D1 is connected to pin 6 of D3, pin 43 of D1 is connected to pin 7 of D4, pin 44 of D1 is connected to pin 6 of D4, pin 40 of D1 is connected to pin 7 of D5, and pin 41 of D1 is connected to pin 6 of D5. Pin 4 of D3 is connected to current limiting resistor R7, pin 1 is connected to current limiting resistor R8, pin 4 of D4 is connected to current limiting resistor R9, pin 1 is connected to current limiting resistor R10, pin 4 of D5 is connected to current limiting resistor R11, pin 1 is connected to current limiting resistor R12.

[0017] In one embodiment, the model of D1 is 74LVC16T245.

[0018] In one embodiment, the model of D2A is 54AC14.

[0019] In one embodiment, the models of D3, D4 and D5 are GH5231S.

[0020] In one embodiment, the fast comparison isolation module includes: a closed-loop Hall current sensor S1, whose 2nd foot is connected to a high-precision sampling resistor RS1 and one end of RT1, the other end of RT1 is connected to one end of resistor RT2, the other end of RT2 is connected to a voltage follower N3A, the output end of the voltage follower N3A is connected to the inverting input end of a comparator N4A, the output end of N4A is connected to a high-speed photoelectric isolation circuit D6 through a resistor RT8, and D6 is connected to a high-speed CMOS enhanced drive type two Schmitt trigger U17A.

[0021] In one embodiment, the voltage follower is of model FX147.

[0022] In one embodiment, the intelligent protection integrated logic module includes: a chip U16 of model SN74LS32, whose pin 8 is connected to pin 3 of trigger U17A, pin 1 of trigger U17A is connected to resistor R1512 and capacitor C1504, and pin 5 of U17A is connected to resistor R1511.

[0023] In one embodiment, the model of U17A is SN74LS74AD.

[0024] In one embodiment, the model of S1 is LA-200.

[0025] In one embodiment, the intelligent protection circuit of the high-voltage and high-power electric rudder system of the present invention: the input end of the SVPWM multi-channel processing module can introduce a 12-channel 3.3V digital SVPWM signal, and realize the direct interconnection of the 5V signal output end with the buffer and high-speed photoelectric isolation circuit. The integrated level conversion chip used is 74LVC16T245, which can realize the input and output bidirectional level conversion of the 16-channel digital SVPWM signal. The buffer circuit is a high-speed CMOS enhanced drive type six Schmitt trigger 54AC14; the SVPWM buffer and isolation circuit can directly drive the gate drive circuit or IPM module circuit after passing through the current limiting resistor R and the photoelectric isolation circuit micro-high-speed optical coupler GH5231s, and at the same time can avoid the influence of the signal transmission delay parameter on the dead time of the IGBT or IPM module circuit, the transmission rate is not less than 5Mb / s, and the transmission time parameters Tplh and Tplh are not more than 160ns.

[0026] In one embodiment, the fast comparison isolation module detects the two-phase current for system vector control through the magnetic balance closed-loop Hall current sensor LA-200, and can realize electrical isolation detection with a range of ±300A. The fast comparison circuit not only transmits the output signal to the digital signal processor after processing by a T-type low-pass filter, but also inputs it to the inverting end of the voltage follower comparator. The operational amplifier required by the voltage follower adopts the FX147 low-noise JFET four-input operational amplifier to compare and determine whether it exceeds the set rated current range, and then outputs the current limiting protection signal after passing through the high-speed optoelectronic isolation circuit. The signal cutoff frequency is designed to be 100KHz, and the linearity deviation is less than 0.15%. It has the advantages of low power consumption, high measurement accuracy, fast response, and low temperature drift.

[0027] In one embodiment, the input end of the intelligent protection integrated logic module is the current limiting protection signals 2A and 2B output by the digital signal processor and the current limiting protection signals 1A and 1B output by the phase current detection and fast comparison circuit after the software phase current limiting protection. After the chip 74LS32 integrated logic or and the D trigger SN74LS74AD outputs the PWM-OE control signal, the control signal controls the input enable end of the SVPWM multi-channel level conversion circuit level conversion chip to achieve the purpose of fast, anti-interference, and dual over-current intelligent protection.

[0028] As a specific embodiment, the working process of the present invention is as follows: (1) Figure 1 As shown in FIG. 1 , after the space control vector, the six-channel PWM1~PWM6 output by the signal processor is converted by the integrated level conversion chip D1 and output to the buffer circuit D2A, and then output to the photoelectric isolation circuit D3~D5 after the pull-up resistors R1~R6 and the current limiting resistors R7~R12; (2) As shown in FIG. Figure 2As shown, the A-phase current signal detected by the closed-loop Hall current sensor S1 is processed by the T-type low-pass filter circuit composed of the high-precision sampling resistor RS1 and RT1, RT2, and CT3, and then input to the in-phase end of the voltage follower. The output signal I_A of the comparator is input to the high-speed photoelectric isolation circuit D6, and the A-phase current limiting protection signal 1A is output after isolation. The output signal I_B of the comparator is input to the high-speed photoelectric isolation circuit D6, and the B-phase current limiting protection signal 1B is output after isolation; (3) Figure 3 As shown, the current limiting protection signals 1A and 1B output by the comparator and the software current limiting control signals 2A and 2B are input to the U16 chip for logic OR operation, and the operation result is input to the clock end of the trigger U17A. When any signal input to the U17A trigger changes from a low level to a high level, the trigger U17A outputs a high level, controls the integrated level conversion chip D1 to stop outputting the SVPWM wave, and then stops the drive circuit from working, thereby achieving the purpose of protecting the IGBT or IPM module circuit.

[0029] The SVPWM multi-channel processing module of the present invention adopts SVPWM multi-channel level conversion, buffering and photoelectric isolation circuits to achieve multi-channel SVPWM parallel and high-speed conversion, has strong driving ability, and can significantly improve the anti-interference ability and control response speed of the high-voltage and high-power electric steering system.

[0030] The fast comparison isolation module of the present invention adopts a magnetic balance type closed-loop Hall current sensor to detect two-phase currents for vector control of a steering system, and can realize complete electrical isolation detection, with a large phase current detection range and a small size.

[0031] The fast comparison isolation module of the present invention not only transmits the two-phase current signal to the digital signal processor after being processed by a T-type low-pass filter, but also inputs it to the inverting end of the voltage follower comparator for comparison and outputs it after being photoelectrically isolated. It has the advantages of strong anti-interference ability, low power consumption, high measurement accuracy, high bandwidth, low temperature drift, etc.; the intelligent protection integrated logic module of the present invention adopts a dual overcurrent intelligent protection integrated logic circuit, and outputs the corresponding logic control signal after the detected two-phase current software current limiting protection and the current limiting protection signal output by the hardware phase current detection and fast comparison circuit through the chip integrated logic and the trigger to control the input and output enable end of the level conversion chip, which can achieve the purpose of fast, anti-interference and reliable protection of high-voltage and high-power electric steering systems.

[0032] The SVPWM multi-channel processing module of the present invention adopts a multi-channel integrated level conversion circuit, a buffer circuit with strong driving capability and a miniature high-speed photoelectric isolation circuit, which enhances the dynamic response speed and anti-interference ability of the rudder system; the fast comparison isolation module of the present invention adopts a high-precision, wide-range, high-speed magnetic balance closed-loop Hall current sensor detection circuit to improve the system control accuracy and anti-interference ability.

[0033] The intelligent protection integrated logic module of the present invention adopts a dual overcurrent intelligent protection circuit that combines isolation, drive and protection in one, which solves the logical defects of a single protection method and the insufficient dynamic response of system control; the intelligent protection integrated logic module of the present invention controls the SVPWM output form after the two-phase current rapid comparison current limiting output signal and the software current limiting control signal are subjected to logical integrated operation and maintained by a trigger to avoid system misprotection.

[0034] The present invention achieves the following beneficial technical effects:

[0035] The structure is simple, including: SVPWM multi-channel processing module, fast comparison isolation module and intelligent protection integrated logic module. It adopts multi-channel integrated level conversion circuit, buffer circuit with strong driving capability and micro-high-speed photoelectric isolation circuit to enhance the dynamic response speed and anti-interference ability of the rudder system, solve the logical defects and insufficient dynamic response of system control in a single protection mode; the two-phase current fast comparison current limiting output signal and software current limiting control signal are subjected to logical synthesis operation and maintained by a trigger to control the SVPWM output form to avoid system misprotection. The circuit has high integration and intelligence, is easy to implement, has low cost and strong adaptability.

[0036] Although the present invention has selected the preferred embodiments disclosed above, it is not intended to limit the present invention. Obviously, it is not necessary and impossible to list all the implementation methods here. Any researcher in the field can adopt the above disclosed embodiments without departing from the spirit and scope of the present invention.

[0037] Therefore, any simple modification, parameter change and modification made to the above-mentioned embodiments based on the research essence of the present invention without departing from the content of the present invention shall fall within the protection scope of the present invention.

Claims

1. An intelligent protection circuit suitable for high-voltage and high-power electric rudder systems, characterized in that: include: SVPWM multi-channel processing module, used to control the six channels PWM1~PWM6 output by the vector post-signal processor, which are converted by the integrated level conversion chip D1 and then output to the buffer circuit D2A, and then output to the photoelectric isolation circuit D3~D5 after the pull-up resistors R1~R6 and the current limiting resistors R7~R12, and then output; The fast comparison isolation module is used to detect the output signal through the closed-loop Hall current sensor S1, and input it to the in-phase end of the voltage follower after processing through the T-type low-pass filter circuit composed of the high-precision sampling resistor RS1 and RT1, RT2, and CT3. The output signal I_A of the comparator is input to the high-speed photoelectric isolation circuit D6, and the A-phase current limiting protection signal 1A is output after isolation. The output signal I_B of the comparator is input to the high-speed photoelectric isolation circuit D6, and the B-phase current limiting protection signal 1B is output after isolation. The intelligent protection integrated logic module is used to input the isolated output 1A, 1B current limiting protection signals and the software current limiting control signals 2A, 2B to the U16 chip for logical OR operation. The operation result is input to the clock end of the trigger U17A. When any signal input to the trigger U17A changes from a low level to a high level, the trigger U17A outputs a high level to control the integrated level conversion chip D1 to stop outputting the SVPWM wave, thereby stopping the drive circuit from working.

2. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 1 is characterized in that: The SVPWM multi-channel processing module includes: an integrated level conversion chip D1, a high-speed CMOS enhanced drive type six Schmitt trigger D2A, and photoelectric isolation circuits D3, D4, and D5, wherein pin 2 of D1 is connected to pin 1 of D2A, pin 3 of D1 is connected to pin 3 of D2A, pin 5 of D1 is connected to pin 5 of D2A, pin 6 of D1 is connected to pin 9 of D2A, pin 8 of D1 is connected to pin 13 of D2A, pin 9 of D1 is connected to pin 11 of D2A, pin 46 of D1 is connected to pin 7 of D3, pin 47 of D1 is connected to pin 6 of D3, pin 43 of D1 is connected to pin 7 of D4, pin 44 of D1 is connected to pin 6 of D4, pin 40 of D1 is connected to pin 7 of D5, and pin 41 of D1 is connected to pin 6 of D5. Pin 4 of D3 is connected to current limiting resistor R7, pin 1 is connected to current limiting resistor R8, pin 4 of D4 is connected to current limiting resistor R9, pin 1 is connected to current limiting resistor R10, pin 4 of D5 is connected to current limiting resistor R11, pin 1 is connected to current limiting resistor R12.

3. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 2 is characterized in that: The model of D1 is 74LVC16T245.

4. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 3 is characterized in that: The model of D2A is 54AC14.

5. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 2 is characterized in that: The D3, D4 and D5 models use the GH5231S.

6. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 5 is characterized in that: The fast comparison isolation module includes: a closed-loop Hall current sensor S1, whose 2nd foot is connected to a high-precision sampling resistor RS1 and one end of RT1, the other end of RT1 is connected to one end of resistor RT2, the other end of RT2 is connected to a voltage follower N3A, the output end of the voltage follower N3A is connected to the inverting input end of the comparator N4A, the output end of N4A is connected to a high-speed photoelectric isolation circuit D6 through a resistor RT8, and D6 is connected to a trigger U17A.

7. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 6 is characterized in that: The model of the voltage follower is FX147.

8. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 1 is characterized in that: The intelligent protection integrated logic module includes: a chip U16 of model SN74LS32, whose pin 8 is connected to pin 3 of trigger U17A, pin 1 of trigger U17A is connected to resistor R1512 and capacitor C1504, and pin 5 of trigger U17A is connected to resistor R1511.

9. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 8 is characterized in that: The trigger U17A adopts the model SN74LS74AD.

10. The intelligent protection circuit adapted to high-voltage and high-power electric rudder system according to claim 7, characterized in that: The model of S1 is LA-200.

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