High-power steering engine driver

Abstract

The invention relates to a high-power steering engine driver, belongs to the technical field of steering engine drivers, and solves the problems that an existing steering engine driver is large in size and weight, low in energy density and easy to cause burnout of the driver due to current limiting failure. The high-power steering engine driver comprises a logic circuit, a power output circuit and a current-limiting protection circuit, wherein the power output circuit is a three-phase star-connected full-bridge driving circuit formed by six power switches; the current-limiting protection circuit collects an induced current signal output when each power switch is switched on so as to generate a current-limiting protection signal; and the logic circuit generates an IPM driving signal according to a rotating speed control signal and a direction control signal sent by the controller, a Hall signal of the motor and a current limiting protection signal so as to carry out pairwise conduction three-phase six-state control on the power switch. The high-power steering engine driver is small in size, light in weight, high in power density and capable of avoiding interference of ground wire noise on sampling current of current-limiting protection during operation of a high-power steering engine.

Description

Technical Field

[0001] The present invention relates to the technical field of steering gear drivers, and in particular to a high-power steering gear driver. Background Art

[0002] With the emergence of new motors, ball screws, harmonic reduction and redundancy technology, electric servos have greatly improved in power, volume, weight, and precise control compared to hydraulic servos. Missile servos tend to develop towards high power and gradually replace high-power hydraulic servos. In order to output high power, the power supply voltage and current of the servos need to be increased. At present, the power supply voltage of high-power electric servos used in large air defense missiles has been increased to 160V or even 270V, the rated current has been increased to 100A, and the peak current is close to 200A. However, in order to achieve high speed and light weight of missiles, the volume and weight of the servo drive cannot be increased indefinitely, which requires high-power electric servos and drives with high power density.

[0003] Most of the existing servo drivers using brushless DC motors are based on logic commutation circuits plus discrete MOS tubes or insulated gate bipolar transistors (IGBTs), but this solution is only suitable for low-power servos and has inevitable drawbacks in the application of high-power servos. Among them, the instantaneous current of high-power servos is close to 200A. Limited by the current level of semiconductor technology, the withstand voltage of high-current MOS tubes is generally low, basically below 250V, so MOS tube solutions are mostly used in the field of low-power servos. In order to improve the withstand voltage, high-power servos mostly use IGBTs, which have a higher withstand voltage value, but the volume and weight of the discretely packaged high-voltage, high-current IGBTs are large, resulting in a high volume and weight of the driver, low energy density, and cannot be used on high-response air defense missiles.

[0004] At the same time, the current limiting schemes of existing servo drives are mostly based on using milliohm (mΩ) sampling resistors to collect the bus current into a small voltage signal, and then compare and protect it through a comparator. This current limiting scheme is easily affected by ground noise and wiring when a high-power servo is running, causing the current limiting to fail and burning the drive. Therefore, it is not suitable for high-power servos.

[0005] Based on the above problems, the existing servo drive solutions cannot meet the current demand for high-power servos. Summary of the invention

[0006] In view of the above analysis, an embodiment of the present invention aims to provide a high-power servo drive to solve the problems of existing servo drives having high volume and weight, low energy density, and easy current limiting failure leading to drive burning.

[0007] The embodiment of the present invention provides a high-power steering gear driver, the high-power steering gear driver comprising: a logic circuit, a power output circuit and a current limiting protection circuit.

[0008] The power output circuit comprises three bridge arms connected in parallel between the positive and negative electrodes of the power supply, two power switches are arranged on each bridge arm, and the three-phase incoming wires of the motor winding are respectively connected between two of the power switches on the three bridge arms;

[0009] The current limiting protection circuit collects the induced current signal output when each power switch is turned on, and generates a current limiting protection signal according to the induced current signal;

[0010] The logic circuit generates an IPM drive signal according to the speed control signal and direction control signal sent by the controller, the Hall signal of the motor and the current limiting protection signal, and controls the power switches of the power output circuit to be turned on in pairs through the IPM drive signal, so that the power output circuit can realize three-phase six-state alternating operation, thereby realizing electronic commutation of the motor winding.

[0011] Based on the further improvement of the above-mentioned high-power servo drive, a current sensing module is provided on the power switch located on the lower bridge arm of the three bridge arms, and the current sensing module is used to sense the conduction current of the power switch and generate an induced current signal proportional to the conduction current.

[0012] Based on the further improvement of the above-mentioned high-power steering gear driver, the current limiting protection circuit includes a sampling resistor, a comparator and an inverter.

[0013] The sampling resistor is connected in series with the output end of the current sensing module, and a sampling voltage signal proportional to the sensing current signal is obtained by collecting the voltage across the sampling resistor, and the sampling voltage signal is input into the comparator.

[0014] The comparator compares the sampled voltage signal with the reference voltage and outputs a fault signal to the inverter. If the sampled voltage signal is higher than the reference voltage signal, the fault signal is a high level signal. If the sampled voltage signal is lower than the reference voltage signal, the fault signal is a low level signal.

[0015] The inverter inverts the phase of the Fault signal to generate the current limiting protection signal.

[0016] Based on the further improvement of the above-mentioned high-power steering gear driver, the current limiting protection circuit also includes a filter,

[0017] The filter is arranged between the sampling resistor and the comparator, and the sampling voltage signal is input into the comparator after being filtered by the filter.

[0018] Based on the further improvement of the above-mentioned high-power steering gear driver, the power switch includes an IGBT device.

[0019] Based on the further improvement of the above-mentioned high-power steering gear driver, the operation logic formula of the logic circuit is:

[0020]

[0021]

[0022] Wherein, HA, HB, HC are the IPM drive signals of the power switches of the three upper bridge arms corresponding to U, V, W of the motor respectively; LA, LB, LC are the IPM drive signals of the power switches of the three lower bridge arms corresponding to U, V, W of the motor respectively; SA, SB, SC are the Hall signals of U, V, W phases of the motor respectively; DIR is the speed control signal, PWM is the direction control signal, and XL is the current limiting protection signal.

[0023] Based on the further improvement of the above high-power steering gear driver, the high-power steering gear driver also includes a driving circuit,

[0024] The driving circuit is connected between the logic circuit and the power output circuit, and is used for amplifying the IPM driving signal generated by the logic circuit and then inputting the amplified signal into the power output circuit.

[0025] Based on the further improvement of the above high-power steering gear driver, the high-power steering gear driver also includes an optical coupling isolation circuit,

[0026] The speed control signal and direction control signal sent by the controller are input into the logic circuit after passing through the optical coupling isolation circuit.

[0027] Based on the further improvement of the above high-power steering gear driver, the high-power steering gear driver also includes a power conversion circuit,

[0028] The power conversion circuit is connected between the power supply and the logic circuit, and the power conversion circuit converts the high voltage provided by the power supply into a low voltage to supply power to the logic circuit.

[0029] Based on further improvement of the above-mentioned high-power servo driver, the power conversion circuit is also connected between the power supply and the Hall sensor of the motor, and the power conversion circuit converts the high voltage provided by the power supply into a low voltage and then supplies power to the Hall sensor.

[0030] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0031] 1. The high-power servo driver of the present invention is mainly composed of a power output circuit, a logic circuit and a current limiting protection circuit, wherein the power output circuit is composed of six power switches. The power switches of the power output circuit are controlled by the logic circuit in pairs to realize three-phase six-state control to realize the electronic commutation of the motor. Compared with the discrete IGBT driver, it has high integration, can effectively reduce the volume and weight of the driver, and achieve high power density.

[0032] 2. In the present invention, a current limiting protection signal is generated based on the collected induced current signal output when each power switch is turned on and output to the logic circuit, so as to realize current limiting protection of the phase current, thereby avoiding the interference of ground wire noise on the sampling current when a high-power servo is running, thereby solving the technical problem of the driver burning due to the easy occurrence of current limiting failure.

[0033] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0035] Figure 1 This is a schematic structural diagram of a high-power steering gear driver according to an embodiment of the present invention;

[0036] Figure 2 FIG. 4 is a schematic diagram of the structure of a power output circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0038] A specific embodiment of the present invention discloses a high-power steering gear driver, such as Figure 1 The high-power steering gear driver of the embodiment of the present invention includes a logic circuit, a power output circuit and a current limiting protection circuit. Figure 2As shown, the power output circuit includes three bridge arms arranged in parallel between the positive and negative poles of the power supply, two power switches are arranged on each bridge arm, and the three-phase incoming lines of the motor winding are respectively connected between the two power switches on the three bridge arms. The current limiting protection circuit collects the induced current signal output when each power switch is turned on, and generates a current limiting protection signal according to the induced current signal; the logic circuit generates an IPM drive signal according to the speed control signal and direction control signal sent by the controller, the Hall signal of the motor and the current limiting protection signal, and controls the power switches of the power output circuit to be turned on in pairs through the IPM drive signal, so that the power output circuit realizes three-phase six-state alternating operation, thereby realizing the electronic commutation of the motor winding.

[0039] In the embodiment of the present invention, the power output circuit is a three-phase star full-bridge drive circuit, and its power switches adopt a three-phase six-state working mode of two-two conduction, that is, when the motor rotates, two power switches located on different bridge arms are turned on at every moment, and the two turned-on power switches are respectively the power switch of the upper bridge arm and the power switch of the lower bridge arm. When the motor rotates, the motor stator winding current is commutated once every 1 / 6 cycle (60° electrical angle), and a power switch is turned on for each commutation, and each power switch is turned on for 120 electrical angles. For example, the conduction order of each power switch is V1V5→V1V6→V2V6→V2V4→V3V4→V3V5... In this cycle, the electronic commutation of the motor (stator winding) is realized.

[0040] Compared with the prior art, the high-power servo driver of the present invention is mainly composed of a power output circuit, a logic circuit and a current limiting protection circuit, wherein the power output circuit is composed of six power switches, and the power switches of the power output circuit are controlled by two-by-two three-phase six-state through the logic circuit to realize the electronic commutation of the motor. Compared with the discrete IGBT driver, it has a high degree of integration, can effectively reduce the volume and weight of the driver, and achieve high power density.

[0041] In the present invention, a current limiting protection signal is generated according to the collected induced current signal output when each power switch is turned on and output to the logic circuit, so as to realize current limiting protection of the phase current, and avoid the interference of ground wire noise on the sampling current when a high-power servo is running, thereby solving the technical problem of the driver burning due to the easy occurrence of current limiting failure.

[0042] In addition, the motor is provided with the Hall sensor for collecting the Hall signal of the motor. The logic circuit is connected with the Hall sensor to receive the Hall signal of the motor.

[0043] In a specific embodiment, a current sensing module is provided on the power switch located at the lower bridge arm of the three bridge arms, and the current sensing module is used to sense the on-current of the power switch and generate an induced current signal proportional to the on-current.

[0044] In this embodiment, the current sensing module senses the on-current of the power switch to obtain the induced current signal. Compared with the existing method of collecting the bus current into a small voltage signal based on a milliohm (mΩ) sampling resistor, the interference of ground wire noise on the sampled current when the high-power servo is running can be avoided, thereby solving the technical problem of the driver burning due to the easy occurrence of current limiting failure.

[0045] Specifically, the power switch may be an IGBT device. The IGBT device has a relatively high withstand voltage and is suitable for high-power steering gears. For example, the withstand voltage of the IGBT device is 600V and the rated current is 150A. During implementation, an IGBT device with a current sensing function may be used.

[0046] In a specific embodiment, the current limiting protection circuit includes a sampling resistor, a comparator and an inverter. The sampling resistor is connected in series with the output end of the current sensing module, and a sampling voltage signal proportional to the sensing current signal is obtained by collecting the voltage across the sampling resistor, and the sampling voltage signal is input into the comparator, and the comparator compares the sampling voltage signal with the reference voltage and outputs a fault signal to the inverter. If the sampling voltage signal is higher than the reference voltage signal, the fault signal is a high level signal, and if the sampling voltage signal is lower than the reference voltage signal, the fault signal is a low level signal, and the inverter generates the current limiting protection signal after inverting the phase of the fault signal.

[0047] Specifically, the reference voltage is generally set to 0.5V.

[0048] In this embodiment, the current limiting protection circuit works based on the induced current signal output by the current sensing module when the power switch is turned on. When the phase current of the motor winding is normal, the on-current of the power switch does not exceed the limit value, the Fault signal output by the comparator is a low-level signal, and after the inverter performs phase inversion, the generated current limiting protection signal is a high-level signal. After the logic circuit performs logical operation, the current limiting protection action is not performed. When the phase current of the motor winding is too large, causing the on-current of the power switch to exceed the limit value, the Fault signal output by the comparator is a high-level signal, and after the inverter performs phase inversion, the generated current limiting protection signal is a low-level signal. After the logic circuit performs logical operation, the current limiting protection action is performed, and the power switches V1, V2, and V3 of the three upper bridge arms are turned off, thereby disconnecting the motor power supply circuit and protecting the power switch.

[0049] Preferably, the current limiting protection circuit further includes a filter, and the filter is arranged between the sampling resistor and the comparator, and the sampling voltage signal is input into the comparator after being filtered by the filter.

[0050] In one embodiment, the operation logic formula of the logic circuit is:

[0051]

[0052]

[0053] Wherein, HA, HB, HC are the IPM drive signals of the power switches of the three upper bridge arms corresponding to U, V, W of the motor respectively; LA, LB, LC are the IPM drive signals of the power switches of the three lower bridge arms corresponding to U, V, W of the motor respectively; SA, SB, SC are the Hall signals of U, V, W phases of the motor respectively; DIR is the direction control signal, PWM is the speed control signal, and XL is the current limiting protection signal.

[0054] It should be noted that, in the formula, the operator Indicates XOR operation; operator "·" indicates AND operation. When DIR=1, it indicates that the motor rotates forward; when DIR=0, it indicates that the motor rotates reversely. When the current limiting protection signal is a high level signal, XL=1; when the current limiting protection signal is a low level signal, XL=0.

[0055] In this embodiment, the logic circuit generates an IPM drive signal for controlling the switch state of the power switches of the three upper bridge arms according to the speed control signal and direction control signal sent by the controller, the Hall signal of the motor, and the current limiting protection signal. The logic circuit generates an IPM drive signal for controlling the switch state of the power switches of the three lower bridge arms according to the speed control signal and direction control signal sent by the controller and the Hall signal of the motor.

[0056] Specifically, the logic circuit generates six IPM drive signals to control the on and off of each power switch respectively, so that only two power switches are turned on at each moment, thereby realizing the commutation control of the motor winding.

[0057] Preferably, the high-power servo driver further comprises a driving circuit, wherein the driving circuit is connected between the logic circuit and the power output circuit and is used for amplifying the IPM driving signal generated by the logic circuit and inputting the amplified signal into the power output circuit.

[0058] Preferably, the high-power steering gear driver also includes an optocoupler isolation circuit. The speed control signal and direction control signal sent by the controller are input into the logic circuit after passing through the optocoupler isolation circuit. The optocoupler isolation circuit is used to isolate the speed control signal and direction control signal generated by the controller from the high-power signal of the driver to prevent the high-power signal from affecting the control signal when the motor is running.

[0059] Preferably, the high-power steering gear driver further comprises a power conversion circuit. The power conversion circuit is connected between the power supply and the logic circuit, and the power conversion circuit converts the high voltage provided by the power supply into a low voltage to supply power to the logic circuit.

[0060] The power conversion circuit is also connected between the power supply and the Hall sensor of the motor. The power conversion circuit converts the high voltage provided by the power supply into a low voltage and then supplies power to the Hall sensor.

[0061] In addition, the power conversion circuit is also connected between the power supply and the optical coupling isolation circuit. Similarly, the power conversion circuit converts the high voltage provided by the power supply into a low voltage to supply power to the optical coupling isolation circuit.

[0062] It should be noted that the power output circuit, logic circuit, current limiting protection circuit, optocoupler isolation circuit, drive circuit, etc. in the embodiment of the present invention can be built into the corresponding chip / module. For example, the power output circuit can be integrated into an IPM module, the logic circuit can be integrated into a logic module, the current limiting protection circuit can be integrated into a current limiting protection module, the optocoupler isolation circuit can be integrated into an optocoupler chip, and the drive circuit can be integrated into a drive chip.

[0063] Example

[0064] The high-power steering gear driver (hereinafter referred to as the driver) of this embodiment includes: a power output circuit, a current limiting protection circuit, a logic circuit, an optical coupling isolation circuit, a power conversion circuit and a drive circuit. In addition, the driver has an interface with a controller and a brushless DC motor. The power output circuit is a three-phase star full-bridge drive circuit composed of six IGBT devices.

[0065] like Figure 1As shown in , when the driver works normally without overcurrent, the PWM control signal and direction control signal sent by the controller are isolated by the optocoupler isolation circuit and then transmitted to the logic circuit. At the same time, the Hall signals of the U, V, and W phases of the motor are also input into the logic circuit. The logic circuit performs logical operations based on the collected signals to generate an IPM drive signal, which is amplified by the drive circuit and output to the power output circuit, thereby controlling the switching state of the IGBT device at the current moment. At the same moment, one power tube is turned on on each of the upper bridge arm and the lower bridge arm. For example, V1 and V5 are currently in the on state, and the current flows from the positive pole of the power supply through V1 into the U phase of the motor, and then through the V phase of the motor, and flows from V5 into the power ground, forming a loop to drive the motor to rotate.

[0066] When the current flowing through the motor winding is too large at a certain moment, causing the IGBT inside the power output circuit to overcurrent, the current limiting protection circuit sends a current limiting protection signal. The current limiting protection signal is input into the logic circuit. After logical operation, the three upper bridge arm IGBT devices V1, V2, and V3 are turned off, thereby disconnecting the motor power supply circuit and protecting the internal IGBT devices.

[0067] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0068] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A high-power servo drive, It is characterized in that The high-power steering gear driver includes: a logic circuit, a power output circuit and a current limiting protection circuit. The power output circuit comprises three bridge arms connected in parallel between the positive and negative electrodes of the power supply, two power switches are arranged on each bridge arm, and the three-phase incoming wires of the motor winding are respectively connected between two of the power switches on the three bridge arms; The current limiting protection circuit collects the induced current signal output when each power switch is turned on, and generates a current limiting protection signal according to the induced current signal; The logic circuit generates an IPM drive signal according to the speed control signal and direction control signal sent by the controller, the Hall signal of the motor and the current limiting protection signal, and controls the power switches of the power output circuit to be turned on in pairs through the IPM drive signal, so that the power output circuit can realize three-phase six-state alternating operation, thereby realizing electronic commutation of the motor winding.

2. The high-power steering gear driver according to claim 1, It is characterized in that A current sensing module is provided on the power switch located at the lower bridge arm of the three bridge arms. The current sensing module is used to sense the on-current of the power switch and generate an induced current signal proportional to the on-current.

3. The high-power steering gear driver according to claim 2, It is characterized in that The current limiting protection circuit includes a sampling resistor, a comparator and an inverter. The sampling resistor is connected in series with the output end of the current sensing module, and a sampling voltage signal proportional to the sensing current signal is obtained by collecting the voltage across the sampling resistor, and the sampling voltage signal is input into the comparator. The comparator compares the sampled voltage signal with the reference voltage and outputs a fault signal to the inverter. If the sampled voltage signal is higher than the reference voltage signal, the fault signal is a high level signal. If the sampled voltage signal is lower than the reference voltage signal, the fault signal is a low level signal. The inverter inverts the phase of the Fault signal to generate the current limiting protection signal.

4. The high-power steering gear driver according to claim 3, It is characterized in that The current limiting protection circuit further includes a filter, The filter is arranged between the sampling resistor and the comparator, and the sampling voltage signal is input into the comparator after being filtered by the filter.

5. The high-power steering gear driver according to any one of claims 1 to 4, It is characterized in that The power switch includes an IGBT device.

6. The high-power steering gear driver according to any one of claims 1 to 4, It is characterized in that The operation logic formula of the logic circuit is: Wherein, HA, HB, HC are the IPM drive signals of the power switches of the three upper bridge arms corresponding to U, V, W of the motor respectively; LA, LB, LC are the IPM drive signals of the power switches of the three lower bridge arms corresponding to U, V, W of the motor respectively; SA, SB, SC are the Hall signals of U, V, W phases of the motor respectively; DIR is the speed control signal, PWM is the direction control signal, and XL is the current limiting protection signal.

7. The high-power steering gear driver according to any one of claims 1 to 4, It is characterized in that The high-power steering gear driver also includes a driving circuit, The driving circuit is connected between the logic circuit and the power output circuit, and is used for amplifying the IPM driving signal generated by the logic circuit and then inputting the amplified signal into the power output circuit.

8. The high-power steering gear driver according to any one of claims 1 to 4, It is characterized in that The high-power steering gear driver also includes an optical coupling isolation circuit. The speed control signal and direction control signal sent by the controller are input into the logic circuit after passing through the optical coupling isolation circuit.

9. The high-power steering gear driver according to any one of claims 1 to 4, It is characterized in that The high-power steering gear driver also includes a power conversion circuit, The power conversion circuit is connected between the power supply and the logic circuit, and the power conversion circuit converts the high voltage provided by the power supply into a low voltage to supply power to the logic circuit.

10. The high-power steering gear driver according to any one of claims 1 to 4, It is characterized in that The power conversion circuit is also connected between the power supply and the Hall sensor of the motor. The power conversion circuit converts the high voltage provided by the power supply into a low voltage and then supplies power to the Hall sensor.

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