A PID controller analog circuit for linear power pack driving

Abstract

The utility model relates to automatic control technical field especially relates to a kind of PID controller analog circuit for linear power component drive, comprising: voltage control loop, current control loop, first level lifting unit, second level lifting unit, minimum selection circuit, linear power component.The utility model effectively solves the problem of high output delay, insufficient response speed in linear power component drive.Through level lifting unit lifting adjustment signal, substantially shorten the invalid time of drive voltage to reach conduction threshold, significantly improve output response speed, adapt to the scene of high timing accuracy requirement.Meanwhile, circuit generates adjustment signal by independent voltage control loop and current control loop respectively, and the minimum value logic of combining minimum selection circuit can better adapt to the needs of constant voltage current limiting or constant current voltage limiting and other working scenes, guarantee the flexible controllability of linear power component output voltage and output current.

Description

Technical Field

[0001] This utility model relates to the field of drive control technology, and in particular to a PID controller analog circuit for driving linear power components. Background Technology

[0002] In the field of electronic circuits, power transistors, represented by MOSFETs, are widely used in various power drive scenarios. Their usage modes are mainly divided into two categories: switching type and linear type.

[0003] For switch-type applications, it is usually sufficient to set the drive level to a fixed value that allows for full conduction and configure an appropriate drive resistor to achieve a faster turn-on rising edge, which meets the application requirements. The technology is relatively mature.

[0004] In linear applications, the driving process requires the driving voltage to reach the critical turn-on threshold of the power transistor. (like Figure 1 (As shown), and then further increased to the target drive voltage value. The stage during which the drive voltage rises from the initial state to the critical conduction threshold is called the ineffective drive time (e.g., Figure 2 As shown in t0-t2, this invalid time directly increases the delay between the drive signal setting value and the actual output of the power component, causing the output response speed of the linear power component to decrease, making it difficult to adapt to application scenarios with high timing accuracy and response speed requirements. This has become a problem that the current linear power component drive circuit urgently needs to solve. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a PID controller analog circuit for driving linear power components.

[0006] This utility model provides a PID controller analog circuit for driving linear power components, including: a voltage control loop, a current control loop, a first level boosting unit, a second level boosting unit, a minimum value selection circuit, and a linear power component; The input terminals of the voltage control loop are a voltage setting signal port and an actual voltage acquisition signal port, respectively, and the output terminal of the voltage control loop is a voltage adjustment signal port. The input terminals of the current control loop are a current setting signal port and an actual current acquisition signal port, respectively, and the output terminal of the current control loop is a current adjustment signal port. The input terminal of the first level-up unit is connected to the output terminal of the voltage control loop, and is used to raise the voltage regulation signal to a preset reference or above. The input terminal of the second level-up unit is connected to the output terminal of the current control loop, and is used to raise the current adjustment signal to above a preset reference. The input terminal of the minimum value selection circuit is connected to the output terminal of the first level-raising unit and the output terminal of the second level-raising unit, respectively, and is used to select the smaller of the raised voltage regulation signal and the raised current regulation signal as the final control signal output. The control terminal of the linear power component is connected to the output terminal of the minimum value selection circuit, and is used to adjust the output voltage or output current of the linear power component according to the final control signal.

[0007] Preferably, the voltage control loop includes a first error amplifier and a first PID regulator, the first PID regulator being connected to the first error amplifier, and the first PID regulator integrating an anti-integral saturation circuit. The first error amplifier receives a voltage setting signal and an actual voltage acquisition signal at its input terminals, and generates a voltage error signal based on the voltage setting signal and the actual voltage acquisition signal. The first PID controller is used to calculate the voltage regulation signal based on the voltage error signal, and the voltage regulation signal is output by the first error amplifier.

[0008] Preferably, the current control loop includes a second error amplifier and a second PID controller, the second PID controller being connected to the second error amplifier, and the second PID controller integrating an anti-integral saturation circuit. The second error amplifier receives a current setting signal and an actual current acquisition signal at its input terminals, and generates a current error signal based on the current setting signal and the actual current acquisition signal. The second PID controller is used to calculate the current adjustment signal based on the current error signal, and the second error amplifier outputs the current adjustment signal.

[0009] Preferably, both the first level-up unit and the second level-up unit are Zener diodes.

[0010] Preferably, both the first level-up unit and the second level-up unit include multiple diodes connected in series.

[0011] Preferably, both the first level-up unit and the second level-up unit are adjustable parallel voltage regulators.

[0012] Preferably, the minimum value selection circuit includes a first diode and a second diode; The cathode of the first diode is connected to the output terminal of the first level-up unit, the cathode of the second diode is connected to the output terminal of the second level-up unit, and the anodes of the first diode and the second diode are connected as the output terminal of the minimum value selection circuit.

[0013] Preferably, it further includes a first reset circuit and a second reset circuit; One end of the first reset circuit is connected to the input terminal of the voltage control loop, and the other end is connected to the output terminal of the first level boosting unit, for resetting the voltage regulation signal to zero when a shutdown command is received; One end of the second reset circuit is connected to the input terminal of the current control loop, and the other end is connected to the output terminal of the second level rise unit, which is used to reset the current adjustment signal when a shutdown command is received.

[0014] Furthermore, both the first reset circuit and the second reset circuit are analog switches.

[0015] Furthermore, the control signal sources for the analog switch include: external program control signals, equipment operating status signals, and logic signals generated based on the comparison between reference values ​​and set values.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention effectively solves the problems of high output delay and insufficient response speed in linear power component driving. By raising the adjustment signal through a level-raising unit, the invalid time for the drive voltage to reach the conduction threshold is significantly shortened, resulting in a significant improvement in output response speed, making it suitable for scenarios with high timing accuracy requirements. Simultaneously, the circuit generates adjustment signals through independent voltage control loops and current control loops, and combined with the minimum value selection circuit's minimum value logic, it can better adapt to the needs of constant voltage current limiting or constant current voltage limiting operating scenarios, ensuring flexible and controllable output voltage and output current of the linear power component. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the critical turn-on threshold of a power transistor in the background technology. Figure 2 This is a schematic diagram comparing the conventional curve and the raised curve in the background art. Figure 3 This is a schematic diagram of a PID controller for driving linear power components in Example 1; Figure 4 This is an analog circuit diagram of the PID controller used for driving linear power components in Example 1; Figure 5 The waveform diagram shows the delay of the PID controller scheme without Zener diode in Example 2 during testing. Figure 6 The output waveform diagram of the PID controller scheme with Zener diode in Example 2 is shown in the test. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to specific embodiments. However, it should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. All technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0019] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer" used in the description of specific embodiments of this utility model to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the utility model solution or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on this utility model.

[0020] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0021] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0022] Furthermore, in the description of the embodiments of this utility model, "several", "multiple", and "several" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0023] Furthermore, in the description of the technical solution of this utility model, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0024] Example 1 This embodiment provides a PID controller analog circuit for driving linear power components (such as...). Figure 3 As shown, it includes a voltage control loop, a current control loop, a first level rise unit, a second level rise unit, a minimum value selection circuit, and a linear power component.

[0025] The input terminals of the voltage control loop are a voltage setting signal port and an actual voltage acquisition signal port, respectively, and the output terminal of the voltage control loop is a voltage adjustment signal port. In optional implementations, such as Figure 4 As shown, the voltage control loop consists of a first error amplifier U1A and a first PID controller. The two input terminals of the first error amplifier U1A acquire the voltage setpoint signal and the actual voltage acquisition signal through resistors R1 and R2, respectively, generating a voltage error signal. The first PID controller integrates an anti-integral saturation circuit and is connected to the first error amplifier U1A. It is used to calculate the voltage adjustment signal based on the voltage error signal, and the voltage adjustment signal is output by the first error amplifier U1A.

[0026] The input terminals of the current control loop are a current setting signal port and an actual current acquisition signal port, respectively, and the output terminal of the current control loop is a current adjustment signal port. In optional implementations, such as Figure 4As shown, the current control loop consists of a second error amplifier U1B and a second PID controller. The two inputs of the second error amplifier U1B acquire the current setting signal and the actual current acquisition signal through resistors R3 and R4, respectively, generating a current error signal. The second PID controller integrates an anti-integral saturation circuit and is connected to the second error amplifier U1B. It is used to calculate the current adjustment signal based on the current error signal, and the second error amplifier U1B outputs the current adjustment signal.

[0027] The input terminal of the first level-up unit is connected to the output terminal of the voltage control loop, and is used to raise the voltage adjustment signal to above a preset reference. The input terminal of the second level-up unit is connected to the output terminal of the current control loop, and is used to raise the current adjustment signal to above a preset reference. The first level boosting unit and the second level boosting unit can be selected in the following ways: In a first optional implementation, both the first level-up unit and the second level-up unit employ Zener diodes (e.g., D1 and D2). The input of the first level-up unit (D1) is connected to the output of the voltage control loop, raising the voltage regulation signal above a preset reference to ensure the signal remains within an effective range during subsequent processing. The input of the second level-up unit (D2) is connected to the output of the current control loop, similarly raising the current regulation signal above a preset reference.

[0028] In a second alternative implementation, both the first level-up unit and the second level-up unit include multiple diodes connected in series, and the level-up is achieved by using the sum of the voltage drops across the series diodes.

[0029] In a third optional implementation, both the first level-up unit and the second level-up unit are adjustable parallel voltage regulators, such as the TL431, configured to stabilize the voltage and achieve level-up. Figure 2 As shown, taking the voltage regulation signal as an example, the Zener diode raises the voltage regulation signal to a preset reference value ( Figure 2 As shown in the figure (V(initial)), the time from the reference value to Vgs(th) is 0-t1. In the conventional way, the time from the initial value to Vgs(th) is 0-t2. The rise time is shortened to t2-t1. By raising the voltage adjustment signal, the invalid drive time is greatly shortened.

[0030] The input terminal of the minimum value selection circuit is connected to the output terminal of the first level-raising unit and the output terminal of the second level-raising unit, respectively, and is used to select the smaller of the raised voltage regulation signal and the raised current regulation signal as the final control signal output. In an optional implementation, the minimum value selection circuit includes a first diode (D3) and a second diode (D4). The cathode of D3 is connected to the output terminal of the first level-up unit, and the cathode of D4 is connected to the output terminal of the second level-up unit. The anodes of D3 and D4 are connected together, forming the output terminal of the minimum value selection circuit. This circuit compares the boosted voltage regulation signal and the boosted current regulation signal, and selects the smaller one as the final control signal output.

[0031] Specifically, the circuit provides a high potential to the anodes of D3 and D4 through a bias circuit consisting of a power supply Vs and a resistor R5 (where capacitor C1 is used for filtering). When any adjustment signal is low, its corresponding diode conducts, clamping the output voltage at a low level, thus achieving a "low on, high off" mechanism. Finally, it automatically selects the smaller of the boosted voltage adjustment signal and the boosted current adjustment signal as the final control signal output.

[0032] The control terminal of the linear power component is connected to the output terminal of the minimum value selection circuit, and is used to adjust the output voltage or output current of the linear power component according to the final control signal.

[0033] In an alternative implementation, the linear power component may be a transistor, MOSFET, or other linear regulation device or a combination thereof, used to drive a load.

[0034] In an optional implementation, a reset circuit is also included, comprising a first analog switch (K1) and a second analog switch (K2). One end of the first analog switch is connected to the input of the voltage control loop, and the other end is connected to the output of the first level-up unit. One end of the second analog switch is connected to the input of the current control loop, and the other end is connected to the output of the second level-up unit. When an output shutdown command is received, the power output stops, K1 and K2 close, short-circuiting the PID controller and quickly clearing the signal on the PID controller, thus resetting the regulation value to zero. Finally, the control signal rapidly drops below the conduction threshold of the linear power component, achieving rapid shutdown. The control signal for the reset circuit can come from external program control signals, device operating status signals (such as RUN / STOP signals), or logic signals generated based on a comparison of a reference value and a set value.

[0035] The first reset circuit is connected to the output terminal of the first level-up unit, and the second reset circuit is connected to the output terminal of the second level-up unit. When the first reset circuit and the second reset circuit are working effectively, they can better ensure that the voltage regulation signal and the current regulation signal are zero, thereby turning off the linear power component.

[0036] During normal operation, the voltage control loop and the current control loop operate independently: The voltage control loop generates a voltage error signal based on the voltage setting signal and the actual voltage acquisition signal, and outputs a voltage regulation signal after PID adjustment.

[0037] The current control loop generates a current error signal based on the current setting signal and the actual current acquisition signal, and outputs a current regulation signal after PID adjustment.

[0038] The two adjustment signals are boosted by Zener diodes and then sent to the minimum value selection circuit. The minimum value selection circuit selects the smaller signal as the final control signal to drive the linear power component. For example, when the load current is close to the set value, the current adjustment signal may be less than the voltage adjustment signal. In this case, the current loop dominates and limits the output current; conversely, the voltage loop dominates.

[0039] When the system needs to be shut down or reset, the zeroing circuit receives a control signal, closes analog switches K1 and K2, short-circuits the PID controller, and quickly clears the regulation value to zero. This avoids the delay caused by integral saturation and improves the system's response speed.

[0040] In this embodiment, the specific compensation network and anti-saturation circuit of the PID controller can be designed according to actual needs, such as using a proportional-integral-derivative combination circuit and a clamping diode. The reference value for level rise is set by the breakdown voltage of the Zener diode. The minimum value selection circuit can also be implemented using other analog comparators, but the diode scheme is preferred in this embodiment because of its simple structure.

[0041] Example 2 Based on the current solution, under the same settings and closed-loop conditions with the same simulated PID values, the effect of the Zener diode on improving the output response time of the linear power component was tested.

[0042] By comparing the waveforms, it can be seen that there is no Zener diode (such as...). Figure 5 (as shown) and has a Zener diode (such as) Figure 6 In the waveform shown, purple (CH1) represents the voltage / current setpoint, green (CH2) represents the voltage / current adjustment signal, and pink (CH3) represents the output of the linear power component.

[0043] Analysis data shows that without a Zener diode, the voltage setpoint pulse width is 2.1ms, the linear power component output is 1.41ms, and the output delay is 0.69ms. With a Zener diode, the voltage setpoint pulse width is also 2.1ms, but the linear power component output is 1.992ms, and the output delay is 0.108ms. This demonstrates that in the PID controller analog circuit, without a Zener diode, the output delay of the linear power component is more than 6 times that with a Zener diode; therefore, adding a Zener diode significantly improves the output delay.

[0044] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A PID controller analog circuit for driving linear power components, characterized in that, include: Voltage control loop, current control loop, first level boosting unit, second level boosting unit, minimum value selection circuit, linear power component; The input terminals of the voltage control loop are a voltage setting signal port and an actual voltage acquisition signal port, respectively, and the output terminal of the voltage control loop is a voltage adjustment signal port. The input terminals of the current control loop are a current setting signal port and an actual current acquisition signal port, respectively, and the output terminal of the current control loop is a current adjustment signal port. The input terminal of the first level-up unit is connected to the output terminal of the voltage control loop, and is used to raise the voltage regulation signal to a preset reference or above. The input terminal of the second level-up unit is connected to the output terminal of the current control loop, and is used to raise the current adjustment signal to above a preset reference. The input terminal of the minimum value selection circuit is connected to the output terminal of the first level-raising unit and the output terminal of the second level-raising unit, respectively, and is used to select the smaller of the raised voltage regulation signal and the raised current regulation signal as the final control signal output. The control terminal of the linear power component is connected to the output terminal of the minimum value selection circuit, and is used to adjust the output voltage or output current of the linear power component according to the final control signal.

2. The PID controller analog circuit for driving linear power components according to claim 1, characterized in that, The voltage control loop includes a first error amplifier and a first PID regulator, the first PID regulator is connected to the first error amplifier, and the first PID regulator integrates an anti-integral saturation circuit. The first error amplifier receives a voltage setting signal and an actual voltage acquisition signal at its input terminals, and generates a voltage error signal based on the voltage setting signal and the actual voltage acquisition signal. The first PID controller is used to calculate the voltage regulation signal based on the voltage error signal, and the voltage regulation signal is output by the first error amplifier.

3. The PID controller analog circuit for driving linear power components according to claim 1, characterized in that, The current control loop includes a second error amplifier and a second PID regulator, the second PID regulator being connected to the second error amplifier, and the second PID regulator integrating an anti-integral saturation circuit. The second error amplifier receives a current setting signal and an actual current acquisition signal at its input terminals, and generates a current error signal based on the current setting signal and the actual current acquisition signal. The second PID controller is used to calculate the current adjustment signal based on the current error signal, and the second error amplifier outputs the current adjustment signal.

4. The PID controller analog circuit for driving linear power components according to claim 1, characterized in that, Both the first level-up unit and the second level-up unit are Zener diodes.

5. The PID controller analog circuit for driving linear power components according to claim 1, characterized in that, Both the first level-up unit and the second level-up unit include multiple diodes connected in series.

6. The PID controller analog circuit for driving linear power components according to claim 1, characterized in that, Both the first level-up unit and the second level-up unit are adjustable parallel voltage regulators.

7. The PID controller analog circuit for driving linear power components according to claim 1, characterized in that, The minimum value selection circuit includes a first diode and a second diode; The cathode of the first diode is connected to the output terminal of the first level-up unit, the cathode of the second diode is connected to the output terminal of the second level-up unit, and the anodes of the first diode and the second diode are connected as the output terminal of the minimum value selection circuit.

8. The PID controller analog circuit for driving linear power components according to claim 1, characterized in that, It also includes a first reset circuit and a second reset circuit; One end of the first reset circuit is connected to the input terminal of the voltage control loop, and the other end is connected to the output terminal of the first level boosting unit, for resetting the voltage regulation signal to zero when a shutdown command is received; One end of the second reset circuit is connected to the input terminal of the current control loop, and the other end is connected to the output terminal of the second level rise unit, which is used to reset the current adjustment signal when a shutdown command is received.

9. A PID controller analog circuit for driving linear power components according to claim 8, characterized in that, Both the first reset circuit and the second reset circuit are analog switches.

10. A PID controller analog circuit for driving linear power components according to claim 9, characterized in that, The control signals for the analog switch come from: external program control signals, equipment operating status signals, and logic signals generated based on the comparison of reference values ​​and set values.

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