Automatic grid-connected control device and method for driving asynchronous generator by expansion machine

Abstract

The invention discloses an automatic grid-connected control device and method for an expansion machine driven asynchronous generator, and the device comprises a voltage signal module which is configured to collect and process a voltage input signal of an input side; the input side comprises a power supply system and a generator driven by an expansion machine, and the generator is an asynchronous generator; the intelligent power line carrier control and communication module is configured to collect and process a rotating speed signal of the generator and transmit the rotating speed signal through a carrier; the carrier transmission comprises the step of eliminating the influence of temperature on a carrier signal based on a phase-locked loop closed-loop compensation method; the central processing controller is configured to receive the processed voltage input signal and the generator rotating speed signal, perform logical operation in combination with phase sequence detection control and rotating speed measurement control, and generate a generator switching-on or switching-off instruction; and the remote signaling output module is configured to receive the switching-on or switching-off instruction of the generator and control the switching-on or switching-off of the generator, so that automatic grid-connected control of the expansion machine driving asynchronous generator is realized.

Description

Technical Field

[0001] The present invention relates to the field of electrical engineering and automation technology, and in particular to an automatic grid-connected control device and method for an expander-driven asynchronous generator. Background Art

[0002] In large-scale petrochemical projects, energy-saving design requirements often require the use of expansion generators to convert excess energy from chemical processes into electrical energy and feed it back to the factory's power distribution system to achieve energy conservation and emission reduction. Currently, this type of design has the following technical difficulties:

[0003] (1) Since the expander is equipped with a generator, the speed change rate of the expander is too high. It is difficult to achieve stable and reliable speed control and regulation by using the expander to drive a conventional synchronous generator.

[0004] (2) In actual engineering applications, the installation location of the expander is in an explosive environment. The cost of explosion-proof facilities such as the excitation machine system and the machine-end PT cabinet required for the synchronous generator is too high. At the same time, the generator protection system, excitation system, demagnetization system, etc. are also required. The system is complex and difficult to implement.

[0005] To address the above problems, the current solution is to use an expander to drive an asynchronous generator. The advantage is that the squirrel cage asynchronous generator has the same structure as the squirrel cage asynchronous motor, and the application technology is mature, especially widely used in explosion-proof environments. Summary of the Invention

[0006] In order to solve the above problems, the present invention proposes an automatic grid-connected control device and method for an expander-driven asynchronous generator, which is suitable for automatic grid-connected control of an expander-driven asynchronous generator. It adopts intelligent power carrier technology and a high-temperature compensation scheme for the carrier signal based on the PLL (phase-locked loop) algorithm, which can realize online monitoring and control of the generator operation status.

[0007] The technical solution adopted in the present invention is as follows:

[0008] An automatic grid-connected control device for an expander-driven asynchronous generator, comprising:

[0009] a voltage signal module configured to collect and process a voltage input signal from an input side; the input side includes a power supply system and a generator driven by an expander, the generator being an asynchronous generator;

[0010] The intelligent power carrier control and communication module is configured to collect and process the generator speed signal and then transmit it via a carrier wave; the carrier wave transmission includes eliminating the influence of temperature on the carrier wave signal based on a phase-locked loop closed-loop compensation method;

[0011] a central processing controller configured to receive the processed voltage input signal and the generator speed signal, and perform logic operations in combination with the phase sequence detection control and the speed measurement control to generate a generator closing or opening command;

[0012] The remote signal output module is configured to receive the generator closing or opening command and control the generator closing or opening, thereby realizing the automatic grid connection control of the expander-driven asynchronous generator.

[0013] Furthermore, the phase sequence detection control includes: detecting the phase sequence of the voltage input signals of the power supply system and the generator side respectively, and performing logical judgment; when the voltage input signals of the power supply system and the generator side are both positive phase sequences, outputting a high level 1; otherwise, outputting a low level 0; the speed measurement control includes: measuring the generator speed, and when the generator speed exceeds the threshold, outputting a high level 1.

[0014] Furthermore, the combined phase sequence detection control and speed measurement control perform logical operations to generate a generator closing or opening instruction, including: when the voltage input signals on the power supply system and the generator side are both positive phase sequences and the generator speed exceeds a threshold, a generator closing instruction is generated; otherwise, a generator opening instruction is generated.

[0015] Furthermore, the phase-locked loop closed-loop compensation method based on the phase-locked loop eliminates the influence of temperature on the carrier signal, including: converting the output of the temperature sensor into a voltage signal and inputting it into the phase-locked loop feedback loop; comparing the phase difference between the output signal and the input signal through the phase detector of the phase-locked loop feedback loop, and then outputting the difference signal to a low-pass filter to eliminate the high-frequency signal therein; then adjusting the carrier frequency through a voltage-controlled oscillator to offset temperature drift; finally, sending the signal output by the voltage-controlled oscillator to the phase detector to complete closed-loop control.

[0016] Furthermore, the automatic grid-connected control device also includes a communication output module, which is configured to communicate data from the voltage signal module, the intelligent power carrier control and communication module, the central processing controller and the remote signaling output module to the power monitoring background.

[0017] An automatic grid-connected control method for an expander-driven asynchronous generator, comprising:

[0018] Collecting and processing a voltage input signal from an input side, the input side including a power supply system and a generator driven by an expander, the generator being an asynchronous generator;

[0019] Collecting and processing the generator speed signal, and then transmitting it through a carrier wave, wherein the carrier wave transmission includes eliminating the influence of temperature on the carrier wave signal based on a phase-locked loop closed-loop compensation method;

[0020] Receives processed voltage input signals and generator speed signals, performs logic operations in conjunction with phase sequence detection control and speed measurement control, and generates generator closing or opening instructions;

[0021] Receive the generator closing or opening command, control the generator closing or opening, and thus realize the automatic grid connection control of the expander driven asynchronous generator.

[0022] Furthermore, the phase sequence detection control includes: detecting the phase sequence of the voltage input signals of the power supply system and the generator side respectively, and performing AND logic judgment; when the voltage input signals of the power supply system and the generator side are both positive phase sequences, outputting a high level 1; otherwise, outputting a low level 0.

[0023] Furthermore, the speed measurement control includes: measuring the generator speed, and outputting a high level 1 when the generator speed exceeds a threshold.

[0024] Furthermore, the combined phase sequence detection control and speed measurement control perform logical operations to generate a generator closing or opening instruction, including: when the voltage input signals on the power supply system and the generator side are both positive phase sequences and the generator speed exceeds a threshold, a generator closing instruction is generated; otherwise, a generator opening instruction is generated.

[0025] Furthermore, the phase-locked loop closed-loop compensation method based on the phase-locked loop eliminates the influence of temperature on the carrier signal, including: converting the output of the temperature sensor into a voltage signal and inputting it into the phase-locked loop feedback loop; comparing the phase difference between the output signal and the input signal through the phase detector of the phase-locked loop feedback loop, and then outputting the difference signal to a low-pass filter to eliminate the high-frequency signal therein; then adjusting the carrier frequency through a voltage-controlled oscillator to offset temperature drift; finally, sending the signal output by the voltage-controlled oscillator to the phase detector to complete closed-loop control.

[0026] The beneficial effects of the present invention are:

[0027] This invention uses an intelligent power carrier control and communication module to collect and process generator speed signals, and employs PLL closed-loop compensation to eliminate the effects of high temperatures on the carrier signal. A central processing control module receives this information, performs logical operations, and issues commands to a remote signaling output module to control the opening and closing of the expansion generator, enabling online monitoring and control of the generator's operating status. This invention provides an economical, advanced, and safe technical solution for controlling expansion generators used in petrochemical projects, particularly in explosion-proof environments.

[0028] The present invention can monitor and control the generator operating status in real time online, greatly improving the system operation safety. At the same time, the speed of the asynchronous generator is collected through intelligent power carrier technology, which reduces the laying of signal control cables, the number of related auxiliary system equipment such as the excitation system and the machine-side PT cabinet, and has high economic benefits. The system structure is simple, which greatly improves the system operation reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of an automatic grid-connected control device for an expander-driven asynchronous generator according to Example 1 of the present invention.

[0030] Figure 2 This is a schematic diagram of an automatic grid-connected control device for an expander-driven asynchronous generator according to Example 1 of the present invention.

[0031] Figure 3 This is a schematic diagram of the PLL closed-loop compensation method according to embodiment 1 of the present invention. DETAILED DESCRIPTION

[0032] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. That is, the embodiments described are only part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] like Figure 1 As shown, this embodiment provides an automatic grid-connected control device for an expander-driven asynchronous generator, including a voltage signal module, an intelligent power carrier control and communication module, a central processing controller, and a remote signaling output module.

[0035] In this embodiment, the voltage signal module is configured to collect and process the voltage input signal of the input side; the input side includes a power supply system and a generator driven by an expander, and the generator is an asynchronous generator.

[0036] The intelligent power carrier control and communication module is configured to collect and process generator speed signals before transmitting them via a carrier wave. During carrier transmission, a phase-locked loop (PLL) closed-loop compensation method eliminates the effects of temperature on the carrier signal, minimizing the effects of high temperatures on the carrier signal's frequency, phase, and amplitude, ensuring communication stability.

[0037] The central processing controller is configured to receive the processed voltage input signal and the generator speed signal, and perform logic operations in combination with the phase sequence detection control and the speed measurement control to generate a generator closing or opening instruction.

[0038] The remote signal output module is configured to receive a generator closing or opening instruction and control the generator closing or opening, thereby realizing automatic grid connection control of the expander-driven asynchronous generator.

[0039] Preferably, the automatic grid-connected control device of this embodiment further includes a communication output module, which is configured to communicate data from the voltage signal module, the intelligent power carrier control and communication module, the central processing controller and the remote signaling output module to the power monitoring background.

[0040] Preferably, if Figure 2 As shown, phase sequence detection control includes detecting the phase sequence of the voltage input signals from the power supply system and the generator, respectively, and performing AND logic judgment. When the voltage input signals from both the power supply system and the generator are positive phase sequence, a high level 1 is output; otherwise, a low level 0 is output. Speed ​​measurement control includes measuring the generator speed and outputting a high level 1 when the generator speed exceeds a threshold (for example, 3000 rpm). Therefore, when the voltage input signals from both the power supply system and the generator are positive phase sequence and the generator speed exceeds the threshold, a generator closing command is generated; otherwise, a generator opening command is generated.

[0041] Preferably, if Figure 3 As shown in FIG, a phase-locked loop closed-loop compensation method is used to eliminate the influence of temperature on the carrier signal, including: using a PLL closed-loop compensation algorithm to convert the temperature sensor output into a voltage signal and input it into the PLL feedback loop; using a phase detector (PFD) to compare the phase difference between the output signal and the input signal, and then outputting the difference signal to a low-pass filter (LPF) to eliminate the high-frequency signal; then using a voltage-controlled oscillator (VCO) to adjust the carrier frequency to offset the temperature drift; finally, sending the signal output by the voltage-controlled oscillator (VCO) to the phase detector (PFD) to complete the closed-loop control.

[0042] Example 2

[0043] This embodiment provides an automatic grid-connected control method for an expander-driven asynchronous generator, including:

[0044] Collect and process the voltage input signal from the input side, which includes the power supply system and the generator driven by the expander, which is an asynchronous generator;

[0045] Collect and process the generator speed signal, and then transmit it through the carrier wave. The carrier wave transmission includes a phase-locked loop closed-loop compensation method to eliminate the influence of temperature on the carrier wave signal.

[0046] Receives processed voltage input signals and generator speed signals, performs logic operations in conjunction with phase sequence detection control and speed measurement control, and generates generator closing or opening instructions;

[0047] Receive the generator closing or opening command, control the generator closing or opening, and thus realize the automatic grid connection control of the expander driven asynchronous generator.

[0048] Preferably, the phase sequence detection control includes: detecting the phase sequence of the voltage input signals of the power supply system and the generator side respectively, and performing AND logic judgment; when the voltage input signals of the power supply system and the generator side are both positive phase sequences, outputting a high level 1; otherwise, outputting a low level 0.

[0049] Preferably, the rotation speed measurement control includes: measuring the rotation speed of the generator, and outputting a high level 1 when the rotation speed of the generator exceeds a threshold.

[0050] Preferably, logical operations are performed in combination with phase sequence detection control and speed measurement control to generate a generator closing or opening instruction, including: when the voltage input signals on the power supply system and the generator side are both positive phase sequences and the generator speed exceeds the threshold, a generator closing instruction is generated; otherwise, a generator opening instruction is generated.

[0051] Preferably, the influence of temperature on the carrier signal is eliminated based on a phase-locked loop closed-loop compensation method, including: converting the output of the temperature sensor into a voltage signal and inputting it into the phase-locked loop feedback loop; comparing the phase difference between the output signal and the input signal through the phase detector of the phase-locked loop feedback loop, and then outputting the difference signal to a low-pass filter to eliminate the high-frequency signal therein; then adjusting the carrier frequency through a voltage-controlled oscillator to offset the temperature drift; finally, sending the signal output by the voltage-controlled oscillator to the phase detector to complete the closed-loop control.

[0052] Example 3

[0053] This embodiment is based on embodiment 1:

[0054] This embodiment provides a computer device including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the automatic grid-connection control method for an expander-driven asynchronous generator according to Embodiment 2. The computer program may be in source code form, object code form, an executable file, or some intermediate form.

[0055] Example 4

[0056] This embodiment is based on embodiment 1:

[0057] This embodiment provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements an automatic grid-connected control method for an expander-driven asynchronous generator according to embodiment 2. The computer program may be in source code form, object code form, an executable file, or some intermediate form. The storage medium includes any entity or device capable of carrying computer program code, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electric carrier signal, a telecommunications signal, and a software distribution medium. It should be noted that the content of the storage medium may be appropriately increased or decreased based on the requirements of legislation and patent practice within a jurisdiction. For example, in some jurisdictions, based on legislation and patent practice, the storage medium does not include electric carrier signals and telecommunications signals.

[0058] It should be noted that, for the sake of simplicity, the aforementioned method embodiments are described as a series of action combinations. However, those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

Claims

1. An automatic grid-connected control device for an expander-driven asynchronous generator, characterized in that: include: a voltage signal module configured to collect and process a voltage input signal from an input side; the input side includes a power supply system and a generator driven by an expander, the generator being an asynchronous generator; The intelligent power carrier control and communication module is configured to collect and process the generator speed signal and then transmit it via a carrier wave; the carrier wave transmission includes eliminating the influence of temperature on the carrier wave signal based on a phase-locked loop closed-loop compensation method; a central processing controller configured to receive the processed voltage input signal and the generator speed signal, and perform logic operations in combination with the phase sequence detection control and the speed measurement control to generate a generator closing or opening command; The remote signal output module is configured to receive the generator closing or opening command and control the generator closing or opening, thereby realizing the automatic grid connection control of the expander-driven asynchronous generator.

2. The automatic grid-connected control device for an expander-driven asynchronous generator according to claim 1, characterized in that: The phase sequence detection control includes: detecting the phase sequence of the voltage input signals of the power supply system and the generator side respectively, and performing AND logic judgment; when the voltage input signals of the power supply system and the generator side are both positive phase sequences, outputting a high level 1; otherwise, outputting a low level 0; the speed measurement control includes: measuring the generator speed, and when the generator speed exceeds a threshold, outputting a high level 1.

3. The automatic grid-connected control device for an expander-driven asynchronous generator according to claim 2, characterized in that: The described combination of phase sequence detection control and speed measurement control performs logical operations to generate a generator closing or opening instruction, including: when the voltage input signals on the power supply system and the generator side are both positive phase sequences and the generator speed exceeds a threshold, generating a generator closing instruction; otherwise, generating a generator opening instruction.

4. The automatic grid-connected control device for an expander-driven asynchronous generator according to claim 1, characterized in that: The phase-locked loop (PLL)-based closed-loop compensation method eliminates the influence of temperature on the carrier signal, including: converting the output of the temperature sensor into a voltage signal and inputting it into the PLL feedback loop; comparing the phase difference between the output signal and the input signal through a phase detector in the PLL feedback loop, and then outputting the difference signal to a low-pass filter to eliminate the high-frequency signal therein; then adjusting the carrier frequency through a voltage-controlled oscillator to offset temperature drift; and finally sending the signal output by the voltage-controlled oscillator to the phase detector to complete closed-loop control.

5. The automatic grid-connected control device for an expander-driven asynchronous generator according to claim 1, characterized in that: It also includes a communication output module, which is configured to communicate data from the voltage signal module, the intelligent power carrier control and communication module, the central processing controller and the remote signaling output module to the power monitoring background.

6. An automatic grid-connected control method for an expander-driven asynchronous generator, characterized in that: include: Collecting and processing a voltage input signal from an input side, the input side including a power supply system and a generator driven by an expander, the generator being an asynchronous generator; Collecting and processing the generator speed signal, and then transmitting it through a carrier wave, wherein the carrier wave transmission includes eliminating the influence of temperature on the carrier wave signal based on a phase-locked loop closed-loop compensation method; Receives processed voltage input signals and generator speed signals, performs logic operations in conjunction with phase sequence detection control and speed measurement control, and generates generator closing or opening instructions; Receive the generator closing or opening command, control the generator closing or opening, and thus realize the automatic grid connection control of the expander driven asynchronous generator.

7. The automatic grid-connected control method for an expander-driven asynchronous generator according to claim 6, characterized in that: The phase sequence detection control includes: detecting the phase sequence of the voltage input signals of the power supply system and the generator side respectively, and performing AND logic judgment; when the voltage input signals of the power supply system and the generator side are both positive phase sequences, outputting a high level 1; otherwise, outputting a low level 0.

8. The automatic grid-connected control method for an expander-driven asynchronous generator according to claim 7, characterized in that: The speed measurement control includes: measuring the speed of the generator, and outputting a high level 1 when the speed of the generator exceeds a threshold.

9. The automatic grid-connected control method for an expander-driven asynchronous generator according to claim 8, characterized in that: The described combination of phase sequence detection control and speed measurement control performs logical operations to generate a generator closing or opening instruction, including: when the voltage input signals on the power supply system and the generator side are both positive phase sequences and the generator speed exceeds a threshold, generating a generator closing instruction; otherwise, generating a generator opening instruction.

10. The automatic grid-connected control method for an expander-driven asynchronous generator according to claim 6, characterized in that: The phase-locked loop (PLL)-based closed-loop compensation method eliminates the influence of temperature on the carrier signal, including: converting the output of the temperature sensor into a voltage signal and inputting it into the PLL feedback loop; comparing the phase difference between the output signal and the input signal through a phase detector in the PLL feedback loop, and then outputting the difference signal to a low-pass filter to eliminate the high-frequency signal therein; then adjusting the carrier frequency through a voltage-controlled oscillator to offset temperature drift; and finally sending the signal output by the voltage-controlled oscillator to the phase detector to complete closed-loop control.

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