Wide-range high-precision universal servo driver and control method thereof

Abstract

The invention relates to the technical field of servo control, and discloses a wide-range high-precision universal servo driver, which comprises an SCR (Selective Catalytic Reduction) rectifying circuit, an IGBT (Insulated Gate Bipolar Translator) full-bridge circuit, a braking circuit, a DSP (Digital Signal Processor) control circuit, a current sensor group, a three-phase relay and a rotary transformer decoding circuit, the SCR rectifying circuit, the IGBT full-bridge circuit, the braking circuit, the current sensor group and the three-phase relay are sequentially cascaded to a motor pre-stage circuit, the rotary transformer decoding circuit is connected with and controls a rotary transformer decoder installed at the output end of a motor, and the DSP control circuit is connected with and controls the SCR rectifying circuit, the IGBT full-bridge circuit, the braking circuit, the current sensor group and the rotary transformer decoding circuit. According to the invention, the same driver can adapt to motors of different voltage grades without replacing the driver, and the driver does not need to be matched with a transformer, is high in compatibility, is lighter in weight, is lower in cost, does not need a customized power supply module, is higher in efficiency, and is better in electromagnetic compatibility.

Description

Technical Field

[0001] This invention relates to the field of servo control technology. Background Technology

[0002] In practical applications, the rated voltage of a permanent magnet synchronous motor must be strictly matched with the rated voltage of the matching driver to ensure the motor's safety and higher control performance. When the driver's voltage level is much higher than the rated voltage of the permanent magnet synchronous motor, such as when a 380VAC driver is matched with a motor with a rated voltage of 28V, 100V, or 300V, the output voltage during the main circuit switching process will far exceed the motor's insulation class. Long-term use will lead to the risk of insulation breakdown in the motor windings, greatly reducing the motor's service life. At the same time, in terms of control performance, it will also lead to increased motor pulsation and noise, and the relevant protection design will be ineffective for low-voltage motors.

[0003] For general 380VAC power supplies or similar three-phase power supplies, if it is necessary to downward match various low-voltage motors, the following method is usually used: 1) The motor and controller are used in a voltage-matched manner, externally via a transformer and rectifier bridge. The three-phase power supply is regulated by the transformer to output three-phase power corresponding to the controller's amplitude, and then rectified by the rectifier bridge before being output to the controller. This method is inconvenient for high-power motors, as the transformer occupies a large volume. Furthermore, for motors with different voltage levels, transformers with different numbers of turns need to be wound to match different controllers. This makes it extremely inconvenient in practical applications and hinders the development of universal and lightweight drivers. 2) The motor and controller voltage levels are still matched, and external rectifier bridge + DC / DC power supply module is used. The three-phase power supply is rectified into DC by the rectifier bridge, and then stepped down by the DC / DC power supply module to output to the controller. Compared with method 1), this method is smaller and simpler to implement. When the motor voltage level is different, it can be achieved by adjusting the output of the DC / DC module. However, in high-power applications, the power supply module usually needs to be customized, which greatly increases the cost in actual product applications. It also increases the efficiency loss of the driver and electromagnetic interference, making it difficult to develop low-cost, high-efficiency and high-reliability solutions.

[0004] In general, permanent magnet synchronous motors and their drivers need to match not only in voltage levels but also in power and current ratings. When a low-power driver drives a high-power motor, it will not meet the motor's operating requirements under rated load, leading to severe overheating and burnout of the driver. Typically, the rated output power and current of the selected driver should not be less than the rated power and current of the motor. However, when the driver's rated output current is much greater than the motor's rated current, the current sensor's range becomes too large, resulting in decreased accuracy of the motor's current loop control and significant torque fluctuations. A common approach to this problem is to amplify the voltage output from the current sensor using an amplification method during low-current detection. This method is simple to operate, but when there is significant environmental interference, noise signals will also be amplified, reducing the signal-to-noise ratio of the current sampling signal and still leading to increased torque fluctuations in the motor.

[0005] The inventors have discovered at least the following problems in the prior art: Summary of the Invention

[0006] The purpose of this invention is to provide a wide-range, high-precision universal servo driver and its control method, which can effectively realize the step-down and voltage regulation of the bus power supply. The same driver can be adapted to motors of different voltage levels without replacing the driver, and no transformer is required. It has strong compatibility and is lighter in weight.

[0007] To address the aforementioned technical problems, this invention provides a wide-range, high-precision universal servo driver, comprising an SCR rectifier circuit, an IGBT full-bridge circuit, a braking circuit, a DSP control circuit, a current sensor group, a three-phase relay, and a resolver decoding circuit. The SCR rectifier circuit, IGBT full-bridge circuit, braking circuit, current sensor group, and three-phase relay are cascaded sequentially in the motor's pre-amplifier circuit. The resolver decoding circuit is connected to a resolver decoder installed at the motor's output terminal. The DSP control circuit is connected to control the SCR rectifier circuit, IGBT full-bridge circuit, braking circuit, current sensor group, and resolver decoding circuit. The SCR rectifier circuit is connected to three-phase AC power in three separate paths, and the IGBT full-bridge circuit is connected to the three-phase windings of the motor in three separate paths.

[0008] The DSP control circuit is connected to the motor armature group position signal via a resolver decoding circuit and a resolver RT. θ and speed signal n Connect to DC bus voltage U dc Connecting phase current I a1~c1 , I a2~c2 DC current is connected I dc ; The DSP control circuit outputs a thyristor control signal G. SCR1~SCR6 Control the SCR rectifier circuit; The DSP control circuit outputs a braking circuit control signal G. zd Control braking circuit; The DSP control circuit outputs a relay control signal G. JCQ Control three-phase relays; The DSP control circuit outputs a pulse signal PWM. 1~6 Control the IGBT full-bridge circuit.

[0009] A bus capacitor is connected in parallel between the braking circuit and the IGBT full-bridge circuit.

[0010] The SCR rectifier circuit uses phase control to achieve bus voltage regulation and bus capacitor surge current suppression; the DSP control circuit uses four-quadrant operation control to generate drive signals for the IGBT full-bridge circuit and braking circuit.

[0011] The current sensor group is connected to the motor via a three-phase relay. The current sensor group outputs three groups of six connections, with each group of two connections connected to a three-phase relay. In the current sensor group, the current range of the current sensors in each of the two connections is different.

[0012] A wide-range, high-precision universal servo control method, employing the wide-range, high-precision universal servo driver as described above, includes the following steps: A. Set the rated voltage and rated current of the motor by receiving instructions via communication or by using built-in software. B. Sampling values ​​of the three-phase AC power supply line voltage U ab ~ U ca Estimate the angle of three-phase input voltage ; C. Sampled values ​​of bus voltage U dc The SCR rectifier circuit drive signal G is generated by combining phase-controlled rectification. SCR1 ~ SCR6 Adjust the bus voltage to the motor's rated voltage; D. Calculate the peak phase current of the load using the rated current of the motor, and control the three-phase relays according to the peak phase current to select the working link of the current sensor group; E. Perform fault diagnosis. If no fault is found, perform FOC calculation. The DSP's EPWM module outputs the drive signal PWM. 1~6 The drive motor operates in a closed loop. If a fault occurs, the fault is reported and the motor stops. In F and FOC operations, the bus voltage is detected. Udc When the bus voltage rises, the motor enters generator mode and outputs a braking circuit drive signal G. zd Braking and voltage reduction are used to complete the four-quadrant operation control of the motor.

[0013] Step B specifically includes the following steps: B1. Obtain the line voltage of the three-phase power input through the AD sampling module of the DSP control circuit. U ab , U bc , U ca ; B2. Calculate the phase voltages of the three-phase power supply inputs respectively. U a =2 / 3 U ab +1 / 3 U bc , U b =2 / 3 U bc +1 / 3 U ca , U c =2 / 3 U ca +1 / 3 U ab Obtain the phase voltage of the three-phase power input U a , U b , U c ; B3. Phase voltage of the three-phase power supply input U a , U b , U c Perform Clark transformation to obtain U a , U β ; B4. Using three-phase estimation to determine phase angle right U a , U β Performing the Park transformation yields U d and U q ; B5, with U qThe estimated phase voltage angular frequency is obtained by performing a PI calculation using the error value. ; B6. By estimating the phase voltage angular frequency With the reference angular frequency of the three-phase power supply Summation followed by integration yields the angle of the three-phase input voltage. .

[0014] Step C specifically includes the following steps: C1, supplied by the motor's rated voltage The reference phase shift was calculated. The reference phase can be calculated using a lookup table method. ; C2, By controlling the DC voltage of the bus U dc Sampling is performed, and the target rated voltage U is compared with the target rated voltage U. d Find the difference.

[0015] C3. The voltage difference is used for PI calculation, and the PI output is used as phase angle compensation, with the reference phase. The control phase angle is obtained by summing the values ​​after passing through the phase angle limit. ; C4. By controlling the phase angle Estimating the phase angle with three phases The comparison generates the SCR drive signal G. SCR1 ~ SCR6 ; Step C4 specifically includes the following steps: C41. Estimating phase angles using three phases Determine the turn-on time and sequence of the SCR rectifier circuit; C42, when 60°≥ ≥ VT1 and VT6 are turned on, while the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to [value missing]. To achieve soft start and prevent bus capacitor current overshoot, at this time, G SCR1 G SCR6 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C43, when 120° ≥ ≥ ≥60°, VT1 and VT2 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR1 G SCR2 The output is high at all times, and low at all other times. SCR1 ~SCR6 All outputs are low; C44, when 180° ≥ ( +120°)≥ ≥120°, VT3 and VT2 are turned on, and the remaining SCRs are turned off. The initial enable phase angle is reduced to [value missing]. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR2 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C45, when 240° ≥ ( +120°)≥ ≥180°, VT3 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to 180°. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C46. When 300° ≥ ( +240°)≥ ≥240°, VT5 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to... To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C47. When 360° ≥ ( +240°)≥ ≥300°, VT5 and VT6 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle is slowly reduced to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR6 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C48. In the driver inoperable state, all SCRs are off, G SCR1 ~ SCR6 All outputs are low.

[0016] Step D specifically includes the following steps: D1. Calculate the peak phase current of the motor's rated load based on the motor's rated current. I pp ; D2, Pass I pp Judgment, when I pp Less than the maximum measuring current of the small-range sensor I max1 When the temperature is -10°C, select a small-range current sensor for initial operation; otherwise, select a large-range current sensor. D3. During closed-loop operation, if a small-range current sensor is initially selected, it can be switched to a large-range current sensor when the motor is under overload conditions. D3. During closed-loop operation, if a large-range current sensor is initially selected, a small-range current sensor can be switched to when the motor has a long-term light load to improve control accuracy.

[0017] Step E specifically includes the following steps: E1. First, during operation, periodic detections are performed on bus overvoltage, bus overcurrent, phase current overcurrent, motor overload, motor overspeed, driver overtemperature, motor overtemperature, etc. If a fault occurs, fault feedback is completed through communication or digital display and other means, and the motor stops at this time. E2, obtained through AD sampling i a ~ i c After Clarke and Park transformations, it becomes i d , i q ; E3, the angle of the motor via the decoding circuit θ and rotational speed n; E4. When position control is required, adjust the motor angle. θ The difference between the angle and the desired target angle is transmitted to the position controller, and the output of the position controller is used as the target value for the speed controller. E5. When performing position control, the output of the position controller is used as the target value for speed control. If only speed control is performed, the target value for speed control is given by an external command. E6. The target speed value is compared with the motor speed. n The difference is then transmitted to the speed controller, and the output of the speed controller is used as the target value of the current controller. E7. When performing position control or speed control, use the output of the speed controller as the target value for current control. i qref If only torque control is performed, the target value for current control is...i qref Given by external instructions; E8, Let i d Current target value i d =0, respectively at i d , i q After subtraction, the output after passing through the current driver is u d , u q ; E9. Converting dq-axis voltages to Park transform u α , u β And after passing through SVPWM, PWM is generated. 1~6 The signal is sent to the IGBT full-bridge circuit, and the IGBT full-bridge circuit outputs the phase voltage signal to the permanent magnet synchronous motor.

[0018] Compared to existing technologies, this invention allows the same driver to be adapted to motors of different voltage levels without the need to replace the driver, and it does not require a transformer, resulting in strong compatibility, lighter weight, lower cost, higher efficiency, and better electromagnetic compatibility without the need for a customized power supply module. The DC bus does not require a buffer circuit; through phase-controlled rectification and soft starting, it avoids inrush current to the bus capacitor, preventing damage to the bus capacitor due to excessive inrush current. Under various power and load conditions, it offers higher current sampling accuracy, higher current sampling signal-to-noise ratio, and smaller torque fluctuations in motor control.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This is a schematic diagram of the connection principle of at least one embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram illustrating the connection principle of the SCR rectifier circuit in China; Figure 3 yes Figure 1A schematic diagram illustrating the connection principle of the braking circuit and the IGBT full-bridge circuit. Figure 4 yes Figure 1 Schematic diagram of phase angle phase-locked loop control principle for three-phase power supply; Figure 5 yes Figure 1 Schematic diagram of voltage loop control principle for intermediate bus voltage; Figure 6 yes Figure 1 Schematic diagram of three-phase control principle of medium-phase controlled rectifier. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this invention. The embodiments can be combined with and referenced by each other without contradiction.

[0023] Example 1 like Figures 1 to 3 The illustrated wide-range, high-precision general-purpose servo driver includes an SCR rectifier circuit, an IGBT full-bridge circuit, a braking circuit, a DSP control circuit, a current sensor group, a three-phase relay, and a resolver decoding circuit. The SCR rectifier circuit, IGBT full-bridge circuit, braking circuit, current sensor group, and three-phase relay are cascaded in the motor pre-stage circuit. The resolver decoding circuit is connected to a resolver decoder installed at the motor output terminal. The DSP control circuit is connected to control the SCR rectifier circuit, IGBT full-bridge circuit, braking circuit, current sensor group, and resolver decoding circuit. The SCR rectifier circuit is connected to three-phase AC power in three separate paths, and the IGBT full-bridge circuit is connected to the three-phase windings of the motor in three separate paths.

[0024] Example 2 Based on Example 1, the DSP control circuit is connected to the motor armature group position signal via a resolver decoding circuit and a resolver RT. θ and speed signal n Connect to DC bus voltage U dc Connecting phase current I a1~c1 , I a2~c2 DC current is connected I dc ; The DSP control circuit outputs a thyristor control signal G. SCR1~SCR6 Control the SCR rectifier circuit; The DSP control circuit outputs a braking circuit control signal G. zd Control braking circuit; The DSP control circuit outputs a relay control signal G. JCQ Control three-phase relays; The DSP control circuit outputs a pulse signal PWM. 1~6 Control the IGBT full-bridge circuit.

[0025] Furthermore, a bus capacitor is connected in parallel between the braking circuit and the IGBT full-bridge circuit.

[0026] Furthermore, the SCR rectifier circuit uses phase control to achieve bus voltage regulation and bus capacitor surge current suppression; the DSP control circuit uses four-quadrant operation control to generate drive signals for the IGBT full-bridge circuit and braking circuit.

[0027] Furthermore, the current sensor group is connected to the motor via a three-phase relay. The current sensor group outputs three groups of six connections, with each group of two connections connected to a three-phase relay. In the current sensor group, the current range of the current sensors in each of the two connections is different.

[0028] Example 3 A wide-range, high-precision, universal servo control method, using Embodiment 1 or Embodiment 2, includes the following steps: A. Set the rated voltage and rated current of the motor by receiving instructions via communication or by using built-in software. B. Sampling values ​​of the three-phase AC power supply line voltage U ab ~ U ca Estimate the angle of three-phase input voltage ; C. Sampled values ​​of bus voltage U dc The SCR rectifier circuit drive signal G is generated by combining phase-controlled rectification. SCR1 ~ SCR6 Adjust the bus voltage to the motor's rated voltage; D. Calculate the peak phase current of the load using the rated current of the motor, and control the three-phase relays according to the peak phase current to select the working link of the current sensor group; E. Perform fault diagnosis. If no fault is found, perform FOC calculation. The DSP's EPWM module outputs the drive signal PWM. 1~6 The drive motor operates in a closed loop. If a fault occurs, the fault is reported and the motor stops. In F and FOC operations, the bus voltage is detected. U dc When the bus voltage rises, the motor enters generator mode and outputs a braking circuit drive signal G. zd Braking and voltage reduction are used to complete the four-quadrant operation control of the motor.

[0029] Example 4 Based on Example 3, step B specifically includes the following steps: B1. Obtain the line voltage of the three-phase power input through the AD sampling module of the DSP control circuit. U ab , U bc , U ca ; B2. Calculate the phase voltages of the three-phase power supply inputs respectively. U a =2 / 3 U ab +1 / 3 U bc , U b =2 / 3 U bc +1 / 3 U ca , U c =2 / 3 U ca +1 / 3 U ab Obtain the phase voltage of the three-phase power input U a , U b , U c ; B3. Phase voltage of the three-phase power supply input U a , U b , U c Perform Clark transformation to obtain U a , U β ; B4. Using three-phase estimation to determine phase angle right U a , U β Performing the Park transformation yields U d and U q; B5, with U q The estimated phase voltage angular frequency is obtained by performing a PI calculation using the error value. ; B6. By estimating the phase voltage angular frequency With the reference angular frequency of the three-phase power supply Summation followed by integration yields the angle of the three-phase input voltage. .

[0030] Furthermore, step C specifically includes the following steps: C1, supplied by the motor's rated voltage The reference phase shift was calculated. The reference phase can be calculated using a lookup table method. ; C2, By controlling the DC voltage of the bus U dc Sampling is performed, and the target rated voltage U is compared with the target rated voltage U. d Find the difference.

[0031] C3. The voltage difference is used for PI calculation, and the PI output is used as phase angle compensation, with the reference phase. The control phase angle is obtained by summing the values ​​after passing through the phase angle limit. ; C4. By controlling the phase angle Estimating the phase angle with three phases The comparison generates the SCR drive signal G. SCR1 ~ SCR6 ; Step C4 specifically includes the following steps: C41. Estimating phase angles using three phases Determine the turn-on time and sequence of the SCR rectifier circuit; C42, when 60°≥ ≥ VT1 and VT6 are turned on, while the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to [value missing]. To achieve soft start and prevent bus capacitor current overshoot, at this time, G SCR1 G SCR6 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C43, when 120° ≥ ≥ ≥60°, VT1 and VT2 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, GSCR1 G SCR2 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C44, when 180° ≥ ( +120°)≥ ≥120°, VT3 and VT2 are turned on, and the remaining SCRs are turned off. The initial enable phase angle is reduced to [value missing]. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR2 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C45, when 240° ≥ ( +120°)≥ ≥180°, VT3 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to 180°. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C46. When 300° ≥ ( +240°)≥ ≥240°, VT5 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to... To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C47. When 360° ≥ ( +240°)≥ ≥300°, VT5 and VT6 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle is slowly reduced to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR6 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C48. In the driver inoperable state, all SCRs are off, G SCR1 ~ SCR6 All outputs are low.

[0032] Furthermore, step D specifically includes the following steps: D1. Calculate the peak phase current of the motor's rated load based on the motor's rated current. I pp ; D2, Pass I pp Judgment, when I pp Less than the maximum measuring current of the small-range sensor I max1 When the temperature is -10°C, select a small-range current sensor for initial operation; otherwise, select a large-range current sensor. D3. During closed-loop operation, if a small-range current sensor is initially selected, it can be switched to a large-range current sensor when the motor is under overload conditions. D3. During closed-loop operation, if a large-range current sensor is initially selected, a small-range current sensor can be switched to when the motor has a long-term light load to improve control accuracy.

[0033] Furthermore, step E specifically includes the following steps: E1. First, during operation, periodic detections are performed on bus overvoltage, bus overcurrent, phase current overcurrent, motor overload, motor overspeed, driver overtemperature, motor overtemperature, etc. If a fault occurs, fault feedback is completed through communication or digital display and other means, and the motor stops at this time. E2, obtained through AD sampling i a ~ i c After Clarke and Park transformations, it becomes i d , i q ; E3, the angle of the motor via the decoding circuit θ and rotational speed n; E4. When position control is required, adjust the motor angle. θ The difference between the angle and the desired target angle is transmitted to the position controller, and the output of the position controller is used as the target value for the speed controller. E5. When performing position control, the output of the position controller is used as the target value for speed control. If only speed control is performed, the target value for speed control is given by an external command. E6. The target speed value is compared with the motor speed. n The difference is then transmitted to the speed controller, and the output of the speed controller is used as the target value of the current controller. E7. When performing position control or speed control, use the output of the speed controller as the target value for current control.i qref If only torque control is performed, the target value for current control is... i qref Given by external instructions; E8, Let i d Current target value i d =0, respectively at i d , i q After subtraction, the output after passing through the current driver is u d , u q ; E9. Converting dq-axis voltages to Park transform u α , u β And after passing through SVPWM, PWM is generated. 1~6 The signal is sent to the IGBT full-bridge circuit, and the IGBT full-bridge circuit outputs the phase voltage signal to the permanent magnet synchronous motor.

[0034] Example 5 Based on the above embodiments, this system is used to drive servo motors of various voltage and power levels. It mainly comprises multiple permanent magnet synchronous motors of typical voltage levels, including: 1) a 300V / 15kW motor with a constant rated speed of 200rpm and a maximum torque of 700Nm; 2) a 540V / 22kW motor with a constant rated speed of 2100rpm and a maximum torque of 93Nm; and 3) a 300V / 1kW motor with a constant rated speed of 200rpm and a maximum torque of 50Nm. The three-phase power input is 380VAC / 50Hz. The driver can be configured with different braking resistors to enable four-quadrant control of the three motors. The application background is a general-purpose ground-based testing platform.

[0035] Figure 1 The diagram shows the proposed high-speed electrically excited doubly salient pole starter generator controller, which includes an SCR rectifier circuit, an IGBT full-bridge circuit, a braking circuit, a DSP control circuit, an output capacitor C, a resolver decoding circuit, and a current sensor group. The DSP control circuit is connected to the motor armature group position signal via the resolver decoding circuit and the resolver RT. θ and speed signal n Connect to DC bus voltage U dc Connecting phase current I a1~c1 , I a2~c2 DC current is connected I dc The DSP control circuit outputs thyristor control signals.G SCR1~SCR6 The signal goes to the SCR rectifier circuit; the DSP control circuit also outputs the braking circuit control signal. G zd The DSP control circuit also outputs relay control signals to the braking circuit. G JCQ The three-phase relay; the DSP control circuit also outputs PWM. 1~6 The circuit connects to the IGBT full-bridge circuit; the output of the IGBT full-bridge circuit is connected to the three-phase contactor, and the other input is connected to the bus capacitor C; the braking circuit is connected to the bus capacitor C, and also to the SCR rectifier circuit, with the other end connected to the braking resistor; one end of the SCR rectifier circuit is connected to the braking circuit, and the other end is connected to the three-phase AC power supply; the positive terminal of the bus capacitor C is connected to the positive terminal of the IGBT full-bridge circuit, the negative terminal is connected to the SCR rectifier circuit, and also to the negative terminal of the IGBT full-bridge circuit; the input of the three-phase relay is connected to the output of the three-phase full-bridge circuit, and the output terminal is connected to the winding of the permanent magnet synchronous motor.

[0036] Figure 2 The diagram shows the working principle of the SCR rectifier circuit, which consists of thyristors VT1 to VT6. The cathodes of VT1, VT3, and VT5 are connected to the positive terminal of the bus, the anode of VT1 is connected to the three-phase input L1, the anode of VT3 is connected to the three-phase input L2, and the anode of VT5 is connected to the three-phase input L3. The anodes of VT2, VT4, and VT6 are connected to the negative terminal of the bus, the cathode of VT2 is connected to the three-phase input L3, the cathode of VT6 is connected to the three-phase input L2, and the cathode of VT4 is connected to the three-phase input L1. Based on a three-phase full-bridge topology of SiC MOS, the rectifier circuit is implemented using SCR, which can achieve soft start of the bus voltage, prevent excessive inrush current from damaging the bus capacitor, and also has a bus voltage reduction function, making the bus voltage adjustable to adapt to motors of different voltage levels and prevent the risk of insulation breakdown in the windings of low-voltage permanent magnet synchronous motors when high-voltage drivers are matched.

[0037] Figure 3 The diagram shown illustrates the braking circuit and three-phase full-bridge working principle of this invention, consisting of an IGBT full-bridge connected to Q... 1~6 The braking circuit consists of Q. zd It consists of diode D1, where the collectors (c) of Q1, Q3, and Q5 are connected to the positive terminal of the bus, the emitters (e) of Q2, Q4, and Q6 are connected to the negative terminal of the bus, and the emitter (e) of Q1 and the collector (c) of Q2 are connected to the three-phase output. i a The emitter (e) of Q3 and the collector (c) of Q4 are connected to the three-phase output i. b The emitter (e) of Q5 and the collector (c) of Q6 are connected to the three-phase output i. c By cooperating with the braking circuit and the IGBT full-bridge circuit, the motor's motoring and generating states are multiplexed, ensuring stable operation of the motor in all four quadrants.

[0038] Example 6 In conjunction with the above embodiments, the following steps are included: A. Set the rated voltage and rated current of the motor through communication or internal software; B. Sampling values ​​of the three-phase AC power supply line voltage U ab ~ U ca Estimate the angle of three-phase input voltage ; C. Sampled values ​​of bus voltage U dc The SCR rectifier circuit drive signal G is generated by combining SCR phase-controlled rectification. SCR1 ~ SCR6 Adjust the bus voltage to the motor's rated voltage; D. Select a suitable current sensor group by calculating the rated current of the motor, and adjust the suitable current sensor group according to the actual load current. E. Perform relevant fault diagnosis. If no faults are found, perform FOC calculation. The DSP's EPWM module outputs the drive signal PWM. 1~6 The motor operates in a closed-loop manner under normal conditions. If a fault occurs, the fault is reported and the motor stops. F. During FOC control operation, bus voltage is detected. U dc When the bus voltage rises, the motor enters generator mode and outputs a braking circuit drive signal G. zd Braking and voltage reduction are implemented to enable four-quadrant operation control of the motor.

[0039] like Figure 4 As shown, the sampled value of the three-phase AC power line voltage mentioned in step B U ab ~ U ca Estimate the angle of three-phase input voltage The steps are as follows: a. Obtain the line voltage of the three-phase power input through the AD sampling module of the DSP control circuit. U ab , U bc , U ca It mainly uses three channels of AD; b. Through U a =2 / 3 U ab +1 / 3 U bc , Ub =2 / 3 U bc +1 / 3 U ca , U c =2 / 3 U ca +1 / 3 U ab Obtain the phase voltage of the three-phase power input U a , U b , U c ; c. Obtained by Clark transformation of three-phase phase voltages U a , U β ; d. Estimate phase angle by setting three phases The value is 0 in the initial state and is used as follows: U a , U β Performing the Park transformation yields U d and U q ; e U q The error value is used for PI calculation, and the output of the PI calculation is used as the angular frequency of the phase voltage. ; f. By estimating the angular frequency With the reference angular frequency of the three-phase power supply Summation is performed to obtain the reference angular frequency of the three-phase power supply. It can be obtained directly from the power source, and then integrated. .

[0040] like Figure 5 As shown, step C involves sampling the bus voltage value. U dc The SCR rectifier circuit drive signal G is generated by combining SCR phase-controlled rectification. SCR1 ~ SCR6 The steps to adjust the bus voltage to the motor's rated voltage are as follows: a. The rated voltage of the motor is transmitted through U d =2.34U l cosα0 is calculated, and to ensure that it does not consume too much execution time, the reference phase of the SCR can be calculated by looking up a table. α 0; b. By adjusting the DC voltage of the bus... U dc Sampling is performed, and the target rated voltage U is compared with the target rated voltage U. d By calculating the difference, closed-loop control of the voltage can be achieved.

[0041] c. The voltage difference is used for PI calculation, and the PI output is used as phase angle compensation, compared with the reference phase angle. The summation, after passing through the phase angle limit, yields the control phase angle of the SCR drive output module. ; e. Through Three-phase estimation Compare the SCR drive signal G generated by the SCR drive output module. SCR1 ~ SCR6 .

[0042] like Figure 6 As shown, step e in step C3 is achieved through... Three-phase estimation Compare the SCR drive signal G generated by the SCR drive output module. SCR1 ~ SCR6 The steps are as follows: a. Angle estimation through three phases Determine the turn-on time and sequence of the SCR rectifier circuit; b. When 60° ≥ ≥ VT1 and VT6 are turned on, while the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to [value missing]. To achieve soft start and prevent bus capacitor current overshoot, at this time, G SCR1 G SCR6 The output is high, and the rest are low. The corresponding SCRs are VT1 and VT6 activated, and G is activated at other times. SCR1 ~ SCR6 All outputs are low, and all SCRs automatically turn off when they cross zero. c. When 120° ≥ ≥ ≥60°, VT1 and VT2 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR1 G SCR2 The output is high, and the rest are low. The corresponding SCRs are VT1 and VT2 activated, and G is activated at other times. SCR1 ~ SCR6 All outputs are low, and all SCRs automatically turn off when they cross zero. d. When 180° ≥ ( +120°)≥ ≥120°, VT3 and VT2 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to 120°. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR2 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low, and all SCRs automatically turn off when they cross zero. e. When 240°≥( +120°)≥ ≥180°, VT3 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to 180°. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low, and all SCRs automatically turn off when they cross zero. f. When 300° ≥ ( +240°)≥ ≥240°, VT5 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to... To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low, and all SCRs automatically turn off when they cross zero. g, when 360° ≥ ( +240°)≥ ≥300°, VT5 and VT6 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle is slowly reduced to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR6 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low, and all SCRs automatically turn off when they cross zero.

[0043] h. In the state of driver failure, all SCRs are turned off, G SCR1 ~ SCR6 All outputs are low, and all SCRs automatically turn off when they cross zero.

[0044] Step D involves selecting a suitable current sensor group based on the motor's rated current, and adjusting the current sensor group according to the actual load current. The steps are as follows: a、I a1 ~I c1 The default current sensor, acting as the driver, is connected in series between the IGBT full-bridge circuits via the normally closed terminals of a three-phase relay. b、I a2 ~I c2 Two sets of current sensors, acting as drivers, are connected in series between the IGBT full-bridge circuits via the normally open terminals of three-phase relays. c. Calculate the peak phase current of the motor's rated load based on the motor's rated current. I pp ; d. Through I pp Judgment, when I pp Less than the maximum measuring current of the small-range sensor I max1 When the temperature is -10°C, select a small-range current sensor for initial operation; otherwise, select a large-range current sensor. e. During closed-loop operation, if a small-range current sensor is initially selected, it can be switched to a large-range current sensor when the motor is under overload. d. During closed-loop operation, if a large-range current sensor is initially selected, when the motor has a long-term light load, it can be switched to a small-range current sensor to improve control accuracy. f. By outputting G zdq The relay drive signal completes the switching of the current sensor group.

[0045] Step E involves relevant fault diagnosis. If no faults are found, FOC calculation is performed, and the DSP's EPWM module outputs the drive signal PWM. 1~6 If the motor is operating normally in a closed-loop manner and a fault occurs, the fault is reported and the motor stops. The steps are as follows: a. First, during operation, periodic detections are performed on bus overvoltage, bus overcurrent, phase current overcurrent, motor overload, motor overspeed, driver overtemperature, motor overtemperature, etc. If a fault occurs, fault feedback is completed through communication or digital display and other means. At this time, the motor stops and no longer responds to related commands. b. Obtained through AD sampling i a ~ i c After Clarke and Park transformations, it becomes i d , i q ; c. The angle of the motor via the decoding circuit θ and rotational speed n; d. When position control is required, adjust the motor angle. θ The difference between the angle and the desired target angle is transmitted to the position controller, and the output of the position controller is used as the target value for the speed controller. e. When performing position control, the output of the position controller is used as the target value for speed control. If only speed control is performed, the target value for speed control is given by an external command. f. Calculate the target speed value and the motor speed. n The difference is then transmitted to the speed controller, and the output of the speed controller is used as the target value of the current controller. g. When performing position control or speed control, use the output of the speed controller as the target value for current control. i qref If only torque control is performed, the target value for current control is... i qref Given by external instructions; h, let i d Current target value i d =0, respectively at i d , i q After subtraction, the output after passing through the current driver is u d , u q ; i. Convert the dq-axis voltage to Park transformation u α , u β And after passing through SVPWM, PWM is generated. 1~6 The signal is sent to the IGBT full-bridge circuit, and the IGBT full-bridge circuit outputs the phase voltage signal to the permanent magnet synchronous motor.

[0046] Step F involves detecting the bus voltage during FOC control operation. U dc When the bus voltage rises, the motor enters generator mode and outputs a braking circuit drive signal G. zd To achieve braking and voltage reduction, and thus enable four-quadrant operation control of the motor, the steps are as follows: a. The FOC is performing normal three-loop control, and the motor is running normally under load; b. When the motor speed and current loop i q When the output directions are the same, the motor operates normally in motoring mode and does not require braking. d. When the motor speed and current loopi q When the output direction is reversed, the motor operates normally in generator mode; d. When the motor is running in generator mode, the bus voltage rises as the load increases. U dc When the braking voltage threshold is greater than 100 kcal / kg U zd At that time, the output braking circuit drive signal G zd A braking resistor is connected in parallel to the busbar for braking and voltage reduction.

[0047] Therefore, this invention offers the following advantages: Compared to the transformer + rectifier bridge approach, by employing SCR phase-controlled rectification, it achieves voltage reduction and regulation of the bus power supply. This allows the same driver to be adapted to motors of different voltage levels without requiring driver replacement, and it eliminates the need for a transformer, resulting in strong compatibility and lighter weight. Compared to the rectifier bridge + DC / DC rectifier bridge approach, the SCR phase-controlled rectification method offers lower costs, eliminates the need for customized power modules, and provides higher efficiency and better electromagnetic compatibility. Furthermore, by using SCR phase-controlled rectification, the DC bus does not require a buffer circuit, and the soft-start method avoids inrush current to the bus capacitor, preventing damage from excessive inrush current. Finally, through the combination of a current sensor group and three-phase relays, the driver achieves higher current sampling accuracy and a higher signal-to-noise ratio under various power and load conditions, resulting in less torque fluctuation in motor control. Those skilled in the art will understand that the above embodiments can be modified in form and detail in practical applications without departing from the spirit and scope of the invention.

Claims

1. A wide-range, high-precision universal servo driver, characterized in that: The system includes an SCR rectifier circuit, an IGBT full-bridge circuit, a braking circuit, a DSP control circuit, a current sensor group, a three-phase relay, and a resolver decoding circuit. The SCR rectifier circuit, IGBT full-bridge circuit, braking circuit, current sensor group, and three-phase relay are cascaded in the front-end circuit of the motor. The resolver decoding circuit is connected to a resolver decoder installed at the output of the motor. The DSP control circuit is connected to control the SCR rectifier circuit, IGBT full-bridge circuit, braking circuit, current sensor group, and resolver decoding circuit. The SCR rectifier circuit is connected to three-phase AC power in three separate paths, and the IGBT full-bridge circuit is connected to the three-phase windings of the motor in three separate paths.

2. The wide-range, high-precision general-purpose servo driver as described in claim 1, characterized in that: The DSP control circuit is connected to the motor armature group position signal via a resolver decoding circuit and a resolver RT. θ and speed signal n Connect to DC bus voltage U dc Connecting phase current I a1~c1 , I a2~c2 DC current is connected I dc ; The DSP control circuit outputs a thyristor control signal G. SCR1~SCR6 Control the SCR rectifier circuit; The DSP control circuit outputs a braking circuit control signal G. zd Control braking circuit; The DSP control circuit outputs a relay control signal G. JCQ Control three-phase relays; The DSP control circuit outputs a pulse signal PWM. 1~6 Control the IGBT full-bridge circuit.

3. The wide-range, high-precision general-purpose servo driver as described in claim 1, characterized in that: A bus capacitor is connected in parallel between the braking circuit and the IGBT full-bridge circuit.

4. The wide-range, high-precision general-purpose servo driver as described in claim 1, characterized in that: The SCR rectifier circuit uses phase control to achieve bus voltage regulation and bus capacitor surge current suppression; the DSP control circuit uses four-quadrant operation control to generate drive signals for the IGBT full-bridge circuit and braking circuit.

5. The wide-range, high-precision general-purpose servo driver as described in claim 1, characterized in that: The current sensor group is connected to the motor via a three-phase relay. The current sensor group outputs three groups of six connections, with each group of two connections connected to a three-phase relay. In the current sensor group, the current range of the current sensors in each of the two connections is different.

6. A wide-range, high-precision, universal servo control method, characterized in that: The method of using a wide-range, high-precision general-purpose servo driver as described in any one of claims 1 to 5 includes the following steps: A. Set the rated voltage and rated current of the motor by receiving instructions via communication or by using built-in software. B. Sampling values ​​of the three-phase AC power supply line voltage U ab ~ U ca Estimate the angle of three-phase input voltage ; C. Sampled values ​​of bus voltage U dc The SCR rectifier circuit drive signal G is generated by combining phase-controlled rectification. SCR1 ~ SCR6 Adjust the bus voltage to the motor's rated voltage; D. Calculate the peak phase current of the load using the rated current of the motor, and control the three-phase relays according to the peak phase current to select the working link of the current sensor group; E. Perform fault diagnosis. If no fault is found, perform FOC calculation. The DSP's EPWM module outputs the drive signal PWM. 1~6 The drive motor operates in a closed loop. If a fault occurs, the fault is reported and the motor stops. In F and FOC operations, the bus voltage is detected. U dc When the bus voltage rises, the motor enters generator mode and outputs a braking circuit drive signal G. zd Braking and voltage reduction are used to complete the four-quadrant operation control of the motor.

7. The wide-range, high-precision, universal servo control method as described in claim 1, characterized in that: Step B specifically includes the following steps: B1. Obtain the line voltage of the three-phase power input through the AD sampling module of the DSP control circuit. U ab , U bc , U ca ; B2. Calculate the phase voltages of the three-phase power supply inputs respectively. U a =2 / 3 U ab +1 / 3 U bc , U b =2 / 3 U bc +1 / 3 U ca , U c =2 / 3 U ca +1 / 3 U ab Obtain the phase voltage of the three-phase power input U a , U b , U c ; B3. Phase voltage of the three-phase power supply input U a , U b , U c Perform Clark transformation to obtain U a , U β ; B4. Using three-phase estimation to determine phase angle right U a , U β Performing the Park transformation yields U d and U q ; B5, with U q The estimated phase voltage angular frequency is obtained by performing a PI calculation using the error value. ; B6. By estimating the phase voltage angular frequency With the reference angular frequency of the three-phase power supply Summation followed by integration yields the angle of the three-phase input voltage. .

8. The wide-range, high-precision, universal servo control method as described in claim 1, characterized in that: Step C specifically includes the following steps: C1, supplied by the motor's rated voltage The reference phase shift was calculated. The reference phase can be calculated using a lookup table method. ; C2, By controlling the DC voltage of the bus U dc Sampling is performed, and the target rated voltage U is compared with the target rated voltage U. d Find the difference. C3. The voltage difference is used for PI calculation, and the PI output is used as phase angle compensation, with the reference phase. The control phase angle is obtained by summing the values ​​after passing through the phase angle limit. ; C4. By controlling the phase angle Estimating the phase angle with three phases The comparison generates the SCR drive signal G. SCR1 ~ SCR6 ; Step C4 specifically includes the following steps: C41. Estimating phase angles using three phases Determine the turn-on time and sequence of the SCR rectifier circuit; C42, when 60°≥ ≥ VT1 and VT6 are turned on, while the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to [value missing]. To achieve soft start and prevent bus capacitor current overshoot, at this time, G SCR1 G SCR6 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C43, when 120° ≥ ≥ ≥60°, VT1 and VT2 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR1 G SCR2 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C44, when 180° ≥ ( +120°)≥ ≥120°, VT3 and VT2 are turned on, and the remaining SCRs are turned off. The initial enable phase angle is reduced to [value missing]. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR2 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C45, when 240° ≥ ( +120°)≥ ≥180°, VT3 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to 180°. To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR3 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C46. When 300° ≥ ( +240°)≥ ≥240°, VT5 and VT4 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle slowly decreases to... To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR4 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C47. When 360° ≥ ( +240°)≥ ≥300°, VT5 and VT6 are turned on, and the remaining SCRs are turned off. During initial enable, the turn-on phase angle is slowly reduced to . To achieve soft start and prevent damage to the bus capacitor from overshoot current, at this time, G SCR5 G SCR6 The output is high at all times, and low at all other times. SCR1 ~ SCR6 All outputs are low; C48. In the driver inoperable state, all SCRs are off, G SCR1 ~ SCR6 All outputs are low.

9. The wide-range, high-precision, universal servo control method as described in claim 1, characterized in that: Step D specifically includes the following steps: D1. Calculate the peak phase current of the motor's rated load based on the motor's rated current. I pp ; D2, Pass I pp Judgment, when I pp Less than the maximum measuring current of the small-range sensor I max1 When the temperature is -10°C, select a small-range current sensor for initial operation; otherwise, select a large-range current sensor. D3. During closed-loop operation, if a small-range current sensor is initially selected, it can be switched to a large-range current sensor when the motor is under overload conditions. D3. During closed-loop operation, if a large-range current sensor is initially selected, a small-range current sensor can be switched to when the motor has a long-term light load to improve control accuracy.

10. The wide-range, high-precision, universal servo control method as described in claim 1, characterized in that: Step E specifically includes the following steps: E1. First, during operation, periodic detections are performed on bus overvoltage, bus overcurrent, phase current overcurrent, motor overload, motor overspeed, driver overtemperature, motor overtemperature, etc. If a fault occurs, fault feedback is completed through communication or digital display and other means, and the motor stops at this time. E2, obtained through AD sampling i a ~ i c After Clarke and Park transformations, it becomes i d , i q ; E3, the angle of the motor via the decoding circuit θ and rotational speed n; E4. When position control is required, adjust the motor angle. θ The difference between the angle and the desired target angle is transmitted to the position controller, and the output of the position controller is used as the target value for the speed controller. E5. When performing position control, the output of the position controller is used as the target value for speed control. If only speed control is performed, the target value for speed control is given by an external command. E6. The target speed value is compared with the motor speed. n The difference is then transmitted to the speed controller, and the output of the speed controller is used as the target value of the current controller. E7. When performing position control or speed control, use the output of the speed controller as the target value for current control. i qref If only torque control is performed, the target value for current control is... i qref Given by external instructions; E8, Let i d Current target value i d =0, respectively at i d , i q After subtraction, the output after passing through the current driver is u d , u q ; E9. Converting dq-axis voltages to Park transform u α , u β And after passing through SVPWM, PWM is generated. 1~6 The signal is sent to the IGBT full-bridge circuit, and the IGBT full-bridge circuit outputs the phase voltage signal to the permanent magnet synchronous motor.

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