Compensation filter and signal processing method and control system based on compensation filter

Abstract

The invention provides a compensation filter and a signal processing method and a control system based on the compensation filter. The compensation filter comprises a first-order inertial filter, a combined differentiator, a second-order inertial filter, a proportional controller and an adder, the input port of the first-order inertial filter and the input port of the combined differentiator are jointly used as the input port of the compensation filter; the output port of the first-order inertial filter is connected with one input port of the summator; the output port of the combined differentiator is connected with the input port of the second-order inertial filter; the output port of the second-order inertial filter is connected with the input port of the proportional controller; the output port of the proportional controller is connected with the other input port of the summator; and the output end of the adder is used as the output port of the compensation filter. By combining the first-order inertial filter, the combined differentiator, the second-order inertial filter, the proportional controller and the summator, adjustable compensation of the low-pass filtering hysteresis characteristic is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of filters, and particularly relates to a compensation filter, a signal processing method based on the compensation filter, and a control system. Background Art

[0002] With the development of energy storage technologies, compressed air energy storage, as an efficient and environmentally friendly energy storage method, has received extensive attention. It stores electrical energy by converting it into the potential energy of compressed air and releases the potential energy of compressed air as electrical energy when needed. During the whole process, the working medium (usually air) undergoes two stages of compression and expansion, and the effective control of these two processes directly affects the efficiency and stability of the system. However, in actual operation, the on-site environment is often complex and changeable, with severe electromagnetic interference and diverse communication methods. These factors may cause the signals in the control system to be disturbed by noise, affecting the system performance.

[0003] To ensure the precise control of the compression and expansion processes of the working medium in the compressed air energy storage system, various means are usually adopted to reduce or eliminate the noise in the control signals. Among them, filters, as a common signal processing tool, are widely used to remove noise or interference while retaining the useful signal components. Filters have the characteristics of simple structure and high reliability, and are particularly suitable for improving the stability and response characteristics of the control system. However, for continuously changing interference signals, traditional filtering methods may not be able to completely eliminate the interference due to the lag problem, especially in application scenarios that require fast response.

[0004] Although filters can effectively suppress noise and improve the performance of the control system, their inherent physical limitations mean that there is always a certain transition bandwidth, which limits the ideal realization of the filtering effect. Especially for first-order inertial filters, although they are easy to implement and low in cost, they show obvious lag phenomena, that is, phase delay, when facing dynamically changing interference. This lag not only reduces the response speed of the control system but may also cause unstable behavior, especially in the compressed air energy storage system with strict requirements for high precision and real-time performance. In addition, the existing filtering schemes lack sufficient flexibility to adapt to the specific requirements in different application scenarios. Summary of the Invention

[0005] In view of this, the present invention aims to provide a compensation filter, a signal processing method based on the compensation filter, and a control system to solve the above problems existing in the existing filtering schemes.

[0006] To solve the above technical problems, the technical solutions provided by the present invention are as follows:

[0007] In the first aspect, the present invention provides a compensation filter, including:

[0008] A first-order inertial filter, a combined differentiator, a second-order inertial filter, a proportional controller, and an adder;

[0009] The input port of the first-order inertial filter and the input port of the combined differentiator jointly serve as the input port of the compensation filter;

[0010] The output port of the first-order inertial filter is connected to one input port of the adder;

[0011] The output port of the combined differentiator is connected to the input port of the second-order inertial filter;

[0012] The output port of the second-order inertial filter is connected to the input port of the proportional controller;

[0013] The output port of the proportional controller is connected to the other input port of the adder;

[0014] The output end of the adder serves as the output port of the compensation filter.

[0015] Furthermore, the transfer function of the first-order inertial filter is:

[0016]

[0017] In the formula, is the Laplace transfer function of the first-order inertial filter, is the common filtering time constant.

[0018] Furthermore, the transfer function of the combined differentiator is:

[0019]

[0020] In the formula, is the Laplace transfer function of the combined differentiator.

[0021] Furthermore, the transfer function of the second-order inertial filter is:

[0022]

[0023] In the formula, is the Laplace transfer function of the second-order inertial filter.

[0024] Furthermore, the transfer function of the proportional controller is:

[0025]

[0026] In the formula, is the Laplace transfer function of the proportional controller, is the proportional control gain.

[0027] Further, the transfer function of the compensation filter is as follows:

[0028]

[0029] In the formula, is the Laplace transfer function of the compensation filter.

[0030] In a second aspect, the present invention provides a signal processing method based on a compensation filter. The compensation filter adopts the compensation filter as in the first aspect. The signal processing method includes the following steps:

[0031] Input the signal to be processed from the input port of the compensation filter;

[0032] Obtain the processed signal from the output port of the compensation filter.

[0033] In a third aspect, the present invention provides a control system based on a compensation filter. The compensation filter adopts the compensation filter as in the first aspect. The control signal of the control system is input to the input port of the compensation filter, and after being processed, it is output from the output port of the compensation filter to the controlled object.

[0034] Further, when there is an interference signal in the control system, the interference signal is introduced into the input end of the control signal in the form of negative feedback to eliminate the interference signal.

[0035] Further, introducing the interference signal into the input end of the control signal in the form of negative feedback includes:

[0036] Performing a subtraction operation on the interference signal and the reference input of the control signal to obtain an adjusted signal, inputting the adjusted signal into the compensation filter for processing, and introducing the processed signal into the input end of the control signal in the form of negative feedback.

[0037] In summary, the present invention provides a compensation filter, including: a first-order inertial filter, a combined differentiator, a second-order inertial filter, a proportional controller, and an adder; the input ports of the first-order inertial filter and the combined differentiator together serve as the input port of the compensation filter; the output port of the first-order inertial filter is connected to one input port of the adder; the output port of the combined differentiator is connected to the input port of the second-order inertial filter; the output port of the second-order inertial filter is connected to the input port of the proportional controller; the output port of the proportional controller is connected to the other input port of the adder; the output end of the adder serves as the output port of the compensation filter. By combining the first-order inertial filter, the combined differentiator, the second-order inertial filter, the proportional controller, and the adder, the present invention realizes adjustable compensation for the low-pass filtering lag characteristic, and enhances the adaptability and flexibility to different application scenarios.

[0038] The present invention also provides a signal processing method and a control system based on a compensation filter, which have the same beneficial effects as those of the compensation filter in specific implementation, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is a flowchart of a compensation filter provided by an embodiment of the present invention;

[0041] Figure 2 It is a block diagram of a control system based on a compensation filter provided by an embodiment of the present invention;

[0042] Figure 3 It is a comparison result diagram of the frequency characteristics of the compensated filter and the first-order inertial filter provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0044] In a compressed air energy storage system, the control of the compression and expansion processes of the working medium faces many challenges. In particular, factors such as a complex on-site environment, severe electromagnetic interference, and diverse communication methods result in significant noise disturbances to the control signal. To address these issues, filters or negative feedback mechanisms are usually adopted in engineering practice to suppress the impact of noise on the performance of the control system. Specifically, by introducing the detected interference signal into the control signal input terminal in the form of negative feedback, these interferences can be offset to a certain extent; however, this method inevitably introduces delays, and it is difficult to completely eliminate those rapidly changing interference signals.

[0045] On the other hand, as a signal processing tool widely used in multiple fields such as electronic engineering, communication, and even image processing, the core function of a filter is to remove unwanted signal components (such as noise) while maintaining or enhancing the useful signal part. Due to its simple structure and high reliability, the filter plays an important role in the control system, not only helping to improve the overall performance of the system but also significantly enhancing the stability and reliability of the system. Nevertheless, traditional filtering methods still face some limitations. For example, there is a certain transition bandwidth that restricts the achievement of the ideal filtering effect, and the inherent phase lag problem may affect the response speed and accuracy of the control system.

[0046] Based on the above background, the present invention proposes a compensation filter and a signal processing method and a control system based on the compensation filter.

[0047] Please refer to Figure 1 , an embodiment of the present invention provides a compensation filter, including:

[0048] A first-order inertial filter, a combined differentiator, a second-order inertial filter, a proportional controller, and an adder;

[0049] The input port of the first-order inertial filter and the input port of the combined differentiator together serve as the input port of the compensation filter;

[0050] The output port of the first-order inertial filter is connected to one input port of the adder;

[0051] The output port of the combined differentiator is connected to the input port of the second-order inertial filter;

[0052] The output port of the second-order inertial filter is connected to the input port of the proportional controller;

[0053] The output port of the proportional controller is connected to the other input port of the adder;

[0054] The output end of the adder serves as the output port of the compensation filter.

[0055] It should be noted that the first-order inertial filter is a simple low-pass filter, and its function is to smooth the input signal and remove high-frequency noise. In the first-order inertial filter, the output signal follows the change of the input signal, but there is a certain delay, and this delay helps to suppress rapidly changing noise components.

[0056] The combined differentiator is used to detect the change rate of the input signal. It emphasizes the transient part of the signal by performing a differentiation operation on the input signal. In the control system, the differentiator can help predict the future change trend of the signal, so as to make a reaction in advance.

[0057] The second-order inertial filter has better filtering performance than the first-order filter, especially in attenuating high-frequency components. It can be formed by cascading two consecutive first-order inertial links or directly designed as a second-order system. The second-order inertial filter can better balance the relationship between stability and response speed.

[0058] The proportional controller (P controller) is one of the most basic types of controllers. It adjusts the output proportionally according to the current error value. If the signal processed by the second-order inertial filter is input to the proportional controller, the controller can generate corresponding control actions based on the deviation between this signal and the set value. The selection of the proportional gain directly affects the steady-state accuracy and dynamic response characteristics of the system.

[0059] The adder is responsible for combining signals from different paths. In this specific design, the adder receives the smoothed signal from the first-order inertial filter and the corrected signal amplified by the proportional controller, and then adds the two to form the final output.

[0060] The working principle of the technical solution of this embodiment is as follows: The input signal first enters the first-order inertial filter and the combined differentiator simultaneously. The first-order inertial filter performs preliminary smoothing on the input signal, reduces the influence of high-frequency noise, and sends its result to one input terminal of the adder. The combined differentiator captures the change trend of the input signal and transmits this information to the second-order inertial filter for further processing. The second-order inertial filter provides a more refined filtering effect on this basis, especially for those high-frequency components that require a higher degree of suppression. The processed signal is then sent to the proportional controller to generate an appropriate control amount according to the gap between the current state and the desired target. Finally, the original signal after the first-order filtering and the signal adjusted by the proportional controller are combined through the adder to obtain the optimized output signal.

[0061] This embodiment provides a compensation filter, which realizes adjustable compensation for the low-pass filtering lag characteristic by combining the first-order inertial filter, the combined differentiator, the second-order inertial filter, the proportional controller and the adder, and enhances the adaptability and flexibility to different application scenarios.

[0062] In one embodiment, the transfer function of the first-order inertial filter is:

[0063]

[0064] In the formula, is the Laplace transfer function of the first-order inertial filter, is the common filtering time constant, with the unit of s, and the general value range is 10 - 100.

[0065] In a further embodiment, the transfer function of the combined differentiator is:

[0066]

[0067] Wherein, is the Laplace transfer function of the combined differentiator.

[0068] In a further embodiment, the transfer function of the second-order inertia filter is:

[0069]

[0070] Wherein, is the Laplace transfer function of the second-order inertia filter.

[0071] In a further embodiment, the transfer function of the proportional controller is:

[0072]

[0073] Wherein, is the Laplace transfer function of the proportional controller, is the proportional control gain, with the unit being dimensionless, and the general value range is: 0.1 - 0.8.

[0074] In a further embodiment, the transfer function of the compensation filter is:

[0075]

[0076] Wherein, is the Laplace transfer function of the compensation filter.

[0077] The above is a detailed introduction to an embodiment of a compensation filter of the present invention. The following is a detailed introduction to an embodiment of a signal processing method based on a low-latency filter of the present invention.

[0078] The embodiment of the present invention provides a signal processing method based on a compensation filter. The compensation filter adopts the compensation filter as described in the foregoing embodiment. The signal processing method includes the following steps:

[0079] S1: Input the signal to be processed from the input port of the compensation filter;

[0080] S2: Obtain the processed signal from the output port of the compensation filter.

[0081] The above is a detailed introduction to an embodiment of a signal processing method based on a low-latency filter of the present invention. The following is a detailed introduction to an embodiment of a control system based on a low-latency filter of the present invention.

[0082] Please refer to Figure 2, embodiments of the present invention also provide a control system based on a compensation filter. The compensation filter adopts the compensation filter of the foregoing embodiments. The control signal of the control system is input into the input port of the compensation filter, and after being processed, it is output from the output port of the compensation filter to the controlled object.

[0083] In a further embodiment, when there is an interference signal in the control system, the interference signal is introduced into the input end of the control signal in the form of negative feedback to eliminate the interference signal.

[0084] Further, introducing the interference signal into the input end of the control signal in the form of negative feedback includes:

[0085] Performing a subtraction operation on the interference signal and the reference input of the control signal to obtain an adjusted signal, inputting the adjusted signal into the compensation filter for processing, and introducing the processed signal into the input end of the control signal in the form of negative feedback.

[0086] Please refer to again Figure 1 , where R is the reference input signal, N is the interference signal, Y is the actual output signal of the system, and R* is the signal after subtracting the interference signal N from the reference input signal R. R* is processed in two paths. One path passes through a first-order inertial filter, and the other path passes through a combined differentiator, a second-order inertial filter, and a proportional control link in sequence. The signals processed by these two paths and the actual output signal Y fed back act on the controlled object G CO (s). Y is also fed back to the input end of the control signal to interact with signals such as the reference input, forming a closed-loop control system to continuously adjust the output, reduce the influence of interference, and make the output approach the expected value.

[0087] In a compressed air energy storage heat exchange device, the temperature at the outlet of the heat exchanger is controlled by regulating the gas flow rate. This signal is greatly affected by common-mode interference, and the filter proposed in this application is adopted. Set the common filtering time constant T F = 20s, and the proportional control gains K p are 0.5, 1.0, and 2.0 respectively, to obtain the comparison results of the frequency characteristics of the compensation filter of the present invention and the frequency characteristics of the first-order inertial filter, as Figure 3 shown, where Figure 3 a is the comparison result diagram of the phase-frequency phase, Figure 3 b is the comparison result diagram of the amplitude-frequency gain.

[0088] Figure 3 Among them, CF is the English abbreviation of the compensation filter of the present invention; P FOIF (ω) is the phase-frequency phase of the first-order inertial filter, with the unit of degree (°); P CF (ω) is the phase-frequency phase of the compensation filter of the present invention, with the unit of degree (°); G FOIFThe amplitude-frequency gain of the first-order inertial filter is (ω), with the unit of dB; G CF The amplitude-frequency gain of the compensation filter of the present invention is G(ω), with the unit of dB;

[0089] Compared with the first-order inertial filter, the compensation filter of the present invention realizes low-pass filtering processing with adjustable low-pass filtering lag characteristics without changing the high-frequency amplitude-frequency gain attenuation characteristics, meeting various needs.

[0090] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compensation filter, characterized in that: include: First-order inertial filter, combined differentiator, second-order inertial filter, proportional controller and adder; The input port of the first-order inertia filter and the input port of the combined differentiator serve together as the input port of the compensation filter; The output port of the first-order inertial filter is connected to an input port of the adder; The output port of the combined differentiator is connected to the input port of the second-order inertial filter; The output port of the second-order inertia filter is connected to the input port of the proportional controller; The output port of the proportional controller is connected to another input port of the adder; The output end of the adder serves as the output port of the compensation filter.

2. The compensation filter according to claim 1, characterized in that The transfer function of the first-order inertial filter is: In the formula, is the Laplace transfer function of the first-order inertial filter, is the common filter time constant.

3. The compensation filter according to claim 2, characterized in that: The transfer function of the combined differentiator is: In the formula, is the Laplace transfer function of the combined differentiator.

4. The compensation filter according to claim 3, characterized in that: The transfer function of the second-order inertial filter is: In the formula, is the Laplace transfer function of the second-order inertial filter.

5. The compensation filter according to claim 4, characterized in that: The transfer function of the proportional controller is: In the formula, is the Laplace transfer function of the proportional controller, is the proportional control gain.

6. The compensation filter according to claim 5, characterized in that: The transfer function of the compensation filter is: In the formula, is the Laplace transfer function of the compensation filter.

7. A signal processing method based on a compensation filter, characterized in that: The compensation filter adopts the compensation filter according to any one of claims 1 to 6, and the signal processing method comprises the following steps: Inputting a signal to be processed from an input port of the compensation filter; The processed signal is obtained from the output port of the compensation filter.

8. A control system based on a compensation filter, characterized in that: The compensation filter adopts the compensation filter as described in any one of claims 1 to 6, and the control signal of the control system is input to the input port of the compensation filter, and is output to the controlled object through the output port of the compensation filter after being processed.

9. The control system based on the compensation filter according to claim 8, characterized in that: When there is an interference signal in the control system, the interference signal is introduced into the input end of the control signal in the form of negative feedback to eliminate the interference signal.

10. The control system based on the compensation filter according to claim 9, characterized in that: Introducing the interference signal into the input end of the control signal in the form of negative feedback, comprising: The interference signal is subtracted from the reference input of the control signal to obtain an adjusted signal, the adjusted signal is input into the compensation filter for processing, and the processed signal is introduced into the input end of the control signal in the form of negative feedback.

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