Control device and control method for liquid cooling circulating pump

Abstract

The invention discloses a control device for a liquid cooling circulating pump, which comprises a frequency converter, a liquid cooling circulating pump and a programmable logic controller, and is characterized in that the frequency converter comprises an information acquisition unit, a core control unit, an emergency switching unit and a communication storage unit. The programmable logic controller, the information acquisition unit, the core control unit and the liquid cooling circulating pump are electrically connected in sequence, the emergency switching unit is electrically connected with the information acquisition unit and the core control unit, and the communication storage unit is electrically connected with the programmable logic controller and the core control unit. The invention further discloses a control method for the liquid cooling circulating pump. According to the technical scheme provided by the invention, violent flow fluctuation cannot be generated after switching, and the liquid cooling circulating pump can operate at the same frequency or basically the same frequency before the fault of the programmable logic controller, so that the original PID set frequency can be maintained, and the control precision and stability of the system can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid cooling circulation pump control for a liquid cooling cabinet, and in particular to a control device and a control method for a liquid cooling circulation pump. Background Art

[0002] As the core power component of the liquid cooling system, the core function of the liquid cooling circulation pump is to drive the coolant (such as water, ethylene glycol aqueous solution, etc.) to flow continuously in a closed loop, and transport the heat generated by the heat source (such as CPU, GPU, etc.) to the radiator for dissipation.

[0003] Currently, the market generally uses PLC (Programmable Logic Controller) analog modules to control the inverter's operating frequency, thereby implementing PID control on the circulation pump. (PID control is the core algorithm for intelligent speed regulation of liquid-cooled circulation pumps. It dynamically converges temperature / flow errors to zero through the coordinated efforts of proportional, integral, and differential control.) At the same time, to address the issue of control interruptions, circulation pump shutdowns, and cessation of liquid cooling delivery due to host computer PLC failures, which can lead to overheating and damage to critical equipment in data center computer rooms, redundant circuits are often added as a remedy. However, while redundant circuits controlled by AC contactors can activate a backup pump to prevent circulation pump shutdown when the primary pump fails, the process of switching from the original control circuit to the redundant circuit generates drastic flow fluctuations. Furthermore, the activated backup pump will run at its maximum frequency, unable to maintain the original PID set frequency, thus compromising the system's control accuracy and stability. Summary of the Invention

[0004] The main purpose of the present invention is to propose a control device and control method for a liquid-cooled circulating pump, aiming to solve the technical problems that the existing liquid-cooled circulating pump adopts a redundant circuit controlled by an AC contactor, which will produce drastic flow fluctuations when switching the circuit, and the started standby pump will run at the maximum frequency.

[0005] To achieve the above-mentioned purpose, the control device for a liquid-cooled circulating pump proposed in the present invention includes a frequency converter, a liquid-cooled circulating pump and a programmable logic controller, the frequency converter includes an information acquisition unit and a core control unit, and the programmable logic controller, the information acquisition unit, the core control unit and the liquid-cooled circulating pump are electrically connected in sequence; the frequency converter also includes an emergency switching unit and a communication storage unit, the emergency switching unit is electrically connected to the information acquisition unit and the core control unit, respectively, and the communication storage unit is electrically connected to the programmable logic controller and the core control unit, respectively.

[0006] Optionally, the programmable logic controller includes an analog output module and a digital output module, the analog output module is electrically connected to the information acquisition unit, and the digital output module is electrically connected to the communication storage unit.

[0007] Optionally, a 24V DC power supply is further included, and the 24V DC power supply supplies power to the programmable logic controller and the emergency switching unit; The reference ground of the analog output module, the reference ground of the digital output module and the common ground of the control terminal of the inverter are commonly connected to the negative pole of the 24V DC power supply to form a star single-point grounding network.

[0008] Optionally, the information acquisition unit includes an information detection circuit and an ACD converter, and the programmable logic controller, the information detection circuit, the ACD converter and the core control unit are electrically connected in sequence.

[0009] Optionally, the communication storage unit includes a pre-stored speed register, and the pre-stored speed register is electrically connected to the programmable logic controller and the core control unit respectively.

[0010] Optionally, the emergency switching unit includes an LO control circuit and an LI3 receiving circuit, the information acquisition unit is electrically connected to the LO control circuit, and the LI3 receiving circuit is electrically connected to the core control unit; The LO control circuit includes an LO-terminal, the LI3 receiving circuit includes an LI3 terminal, and the LO-terminal and the LI3 terminal are short-circuited.

[0011] Optionally, the core control unit includes a control source selector, and the control source selector is electrically connected to the information acquisition unit, the communication storage unit and the emergency switching unit respectively.

[0012] Optionally, the information acquisition unit includes a fixed first parameter, the first parameter being fixed to a value of 0x0A, for enabling analog signal loss detection; The emergency switching unit includes a fixed second parameter and a third parameter. The second parameter is fixed to a value of 0x7B for binding the logic output terminal to a signal loss event. The third parameter is fixed to a value of 0xC3 for configuring a preset speed trigger logic.

[0013] The present invention also discloses a control method for a liquid cooling circulation pump, which is applied to the control device for the liquid cooling circulation pump as described above, and comprises the following steps: Step S1: When the programmable logic controller operates normally, the programmable logic controller continuously outputs a first control signal and a second control signal. The signal acquisition unit receives the first control signal and transmits it to the core control unit. The core control unit performs PID control on the liquid cooling circulation pump according to the first control signal. At the same time, the communication storage unit receives and stores the second control signal. Step S2: When the programmable logic controller fails, the information acquisition unit detects that the first control signal is lost and outputs a switching signal. The emergency switching unit triggers the core control unit according to the switching signal, causing the core control unit to switch to a state of running at an internal preset speed. Step S3: After the core control unit is switched, the core control unit reads the second control signal stored in the communication storage unit, and controls the frequency of the liquid cooling circulation pump according to the second control signal; Step S4: When the programmable logic controller is repaired and back online, the programmable logic controller re-outputs the first control signal and the second control signal. The signal acquisition unit receives the first control signal again and transmits it to the core control unit, and stops outputting the switching signal. The emergency switching unit stops triggering the core control unit. The core control unit implements PID control on the liquid cooling circulation pump according to the first control signal. At the same time, the communication storage unit receives and stores the second control signal.

[0014] The technical solution of the present invention has the following beneficial effects: This control device for a liquid-cooling circulating pump continuously outputs a first control signal (analog signal) and a second control signal (digital signal) through a programmable logic controller (PLC). The first control signal is received by an information acquisition unit and transmitted to a core control unit to implement PID control of the liquid-cooling circulating pump. Simultaneously, the second control signal output by the PLC is received and stored by a communication storage unit. When the PLC fails, the information acquisition unit detects the loss of the first control signal output by the PLC and then outputs a switching signal to an emergency switching unit. The emergency switching unit, in response to the switching signal, triggers the core control unit to switch to an internally preset speed, reads the second control signal stored in the communication storage unit, and then controls the frequency of the liquid-cooling circulating pump based on the second control signal.

[0015] In the present invention, the programmable logic controller continuously outputs and writes a second control signal, which is updated in real time, to the communication storage unit at a relatively high frequency (e.g., 100ms / time), and the core control unit reads the most recently stored second control signal. Therefore, after a programmable logic controller fails, the frequency of the liquid-cooling circulation pump controlled by the core control unit based on the second control signal is the same or substantially the same as the control frequency before the programmable logic controller failed. Compared to the redundant circuit controlled by an AC contactor in the prior art, this design does not produce drastic flow fluctuations after switching, and the liquid-cooling circulation pump will operate at the same frequency or substantially the same frequency as before the programmable logic controller failed. This helps maintain the original PID set frequency, thereby ensuring the control accuracy and stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0017] Figure 1 This is a circuit principle block diagram of a control device for a liquid-cooling circulating pump according to the present invention; Figure 2 This is a circuit schematic diagram of a control device for a liquid-cooling circulating pump according to the present invention; Figure 3 The present invention is a flow chart of the steps of a control method for a liquid-cooling circulating pump.

[0018] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0021] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] The present invention provides a control device for a liquid-cooling circulating pump.

[0023] like Figures 1 to 2As shown, in the first embodiment of the present invention, the control device for a liquid-cooling circulation pump includes a frequency converter, a liquid-cooling circulation pump, and a programmable logic controller. The frequency converter includes an information acquisition unit, a core control unit, an emergency switching unit, and a communication storage unit. Specifically, the programmable logic controller, the information acquisition unit, the core control unit, and the liquid-cooling circulation pump are electrically connected in sequence, the emergency switching unit is electrically connected to the information acquisition unit and the core control unit, respectively, and the communication storage unit is electrically connected to the programmable logic controller and the core control unit, respectively.

[0024] It is worth noting that the control device for a liquid-cooling circulating pump further includes a first power supply and a second power supply. The first power supply is used to power the main circuit of the inverter and the liquid-cooling circulating pump, and the second power supply is used to power the programmable logic controller and the inverter's control circuit. Specifically, the first power supply is a 380V three-phase power supply, and the second power supply is a 24V DC power supply. Since the technical principles for powering the first and second power supplies are mature existing technologies, they will not be further described in this embodiment.

[0025] This control device for a liquid-cooling circulating pump continuously outputs a first control signal (analog signal) and a second control signal (digital signal) through a programmable logic controller (PLC). The first control signal is received by an information acquisition unit and transmitted to a core control unit to implement PID control of the liquid-cooling circulating pump. Simultaneously, the second control signal output by the PLC is received and stored by a communication storage unit. When the PLC fails, the information acquisition unit detects the loss of the first control signal output by the PLC and then outputs a switching signal to an emergency switching unit. The emergency switching unit, in response to the switching signal, triggers the core control unit to switch to an internally preset speed, reads the second control signal stored in the communication storage unit, and then controls the frequency of the liquid-cooling circulating pump based on the second control signal.

[0026] In this embodiment, the programmable logic controller continuously outputs and writes a real-time updated second control signal to the communication storage unit at a relatively high frequency (e.g., 100 ms / time), and the core control unit reads the most recently stored second control signal. Therefore, after a programmable logic controller failure, the frequency of the liquid-cooling circulating pump controlled by the core control unit based on the second control signal is the same or substantially the same as the control frequency before the programmable logic controller failure. Compared to the redundant circuit controlled by an AC contactor in the prior art, this design does not produce drastic flow fluctuations after switching, and the liquid-cooling circulating pump will operate at the same frequency or substantially the same frequency as before the programmable logic controller failure. This helps maintain the original PID set frequency, thereby ensuring the control accuracy and stability of the system.

[0027] Optionally, the programmable logic controller includes an analog output module and a digital output module. The analog output module is electrically connected to the information acquisition unit, and the digital output module is electrically connected to the communication storage unit. Specifically, the analog output module is an AO module, which is used to output a first control signal (analog signal) to the information acquisition unit; the digital output module is an RS485 communication module, which is used to output a second control signal (digital signal) to the communication storage unit. In this embodiment, the analog signal is a continuously changing current signal (4-20mA) that is used to directly drive the frequency setting port of the inverter, thereby continuously adjusting the frequency of the liquid cooling circulation pump. The above-mentioned digital signal is a discrete data packet transmitted based on a serial communication protocol and is a discrete liquid cooling circulation pump control instruction generated by the programmable logic controller according to a certain frequency.

[0028] like Figure 2 As shown, in this embodiment, the above-mentioned 24V DC power supply supplies power to the programmable logic controller and the emergency switching unit. Specifically, the reference ground of the analog output module, the reference ground of the digital output module, and the common ground of the control terminal of the inverter are connected to the negative pole of the 24V DC power supply to form a star-shaped single-point grounding network. This design enables all reference grounds to converge at a unique node (24V negative pole), forming a zero-impedance path (grounding wire cross-sectional area ≥ 2.5mm²) and a Faraday shield (single-end grounding of the twisted-pair shield of the signal line), thereby reducing the potential difference between the COM terminals and the 4-20mA signal noise amplitude, reducing the fluctuation rate of the liquid cooling flow, improving the AI ​​signal accuracy, achieving "zero potential reference unification", and eliminating ground loop interference.

[0029] In addition, the programmable logic controller and the inverter form a transmission path for the first control signal by connecting the AI ​​terminal and the AI1 terminal, and form a transmission path for the second control signal by connecting the 4 terminal and the B terminal and the 5 terminal and the A terminal.

[0030] In this embodiment, the information acquisition unit specifically includes an information detection circuit and an ACD converter. The programmable logic controller, the information detection circuit, the ACD converter, and the core control unit are electrically connected in sequence. The emergency switching unit includes an LO control circuit and an LI3 receiving circuit. The information acquisition unit is electrically connected to the LO control circuit, and the LI3 receiving circuit is electrically connected to the core control unit. The LO control circuit includes an LO- terminal, and the LI3 receiving circuit includes an LI3 terminal. The LO- terminal and the LI3 terminal are short-circuited. The communication storage unit specifically includes a pre-stored speed register, which is electrically connected to the programmable logic controller and the core control unit, respectively. The core control unit specifically includes a control source selector, a frequency setting processor, a PWM generator, and an IGBT switching circuit. The control source selector is electrically connected to the information acquisition unit, the communication storage unit, and the emergency switching unit, respectively. The control source selector, the frequency setting processor, the PWM generator, the IGBT switching circuit, and the liquid cooling circulation pump are electrically connected in sequence.

[0031] Specifically, the information detection circuit includes a fixed first parameter (204.0) with a fixed value of 0x0A, which is used to enable analog signal loss detection. The LO control circuit includes a fixed second parameter (206.0) with a fixed value of 0x7B, which is used to bind the logic output terminal to a signal loss event. The LI3 receiving circuit includes a fixed third parameter (507.0) with a fixed value of 0xC3, which is used to configure the preset speed trigger logic. In this embodiment, the first parameter (204.0) is the signal loss detection enable parameter; the second parameter (206.0) is the fault output mapping parameter; and the third parameter (507.0) is the control source switching trigger parameter. These three parameters are stored in a one-time programmable memory (OTP) and are permanently fixed after writing. They are protected by a write protection circuit. Compared to modifiable parameter designs, fixed parameters improve anti-interference capabilities, preventing redundant functions from failing due to misoperation and preventing parameter resets due to electromagnetic interference, which could cause system crashes.

[0032] like Figure 3 As shown, the present invention also discloses a control method for a liquid cooling circulation pump, which is applied to the control device for the liquid cooling circulation pump as described above, and includes the following steps: Step S1: When the programmable logic controller (PLC) is operating normally, it continuously outputs a first control signal and a second control signal. The signal acquisition unit receives the first control signal and transmits it to the core control unit. The core control unit implements PID control of the liquid cooling circulation pump based on the first control signal. Simultaneously, the communication storage unit receives and stores the second control signal. Specifically, the PLC continuously outputs the first control signal, which is transmitted via the AI ​​and AI1 terminals to the signal detection circuit. The PID control of the liquid cooling circulation pump is then implemented via the ADC converter and the core control unit. The second control signal is transmitted via the RS485 data synchronization channel to the pre-stored speed register for pre-storage.

[0033] Step S2: When the programmable logic controller fails, the information acquisition unit detects the loss of the first control signal and outputs a switching signal. The emergency switching unit triggers the core control unit based on the switching signal, causing it to switch to an internally preset speed. Specifically, the signal detection circuit monitors the signal status of the AI1 terminal in real time. When the programmable logic controller fails, the current at the AI1 terminal drops from 4-20 mA to less than 3.6 mA, indicating the loss of the first control signal. The LO control circuit short-circuits the LO- terminal and the LI3 terminal to transmit a switching signal to the LI3 receiving circuit after the information detection circuit determines the loss of the first control signal. Furthermore, the control source selector includes a multiplexer, which selects the control signal source, i.e., switches between analog and digital signals, through the multiplexer. It is worth noting that the principle of signal source switching achieved through the coordination of the signal detection circuit, the LO control circuit, the LI3 receiving circuit, and the control source selector is well-established and will not be further elaborated in this embodiment.

[0034] Step S3: After the core control unit switches, it reads the second control signal stored in the communication storage unit and controls the frequency of the liquid cooling circulation pump based on the second control signal. Specifically, after the control source selector switches the signal source, it reads the second control signal from the pre-stored speed register and then controls the frequency of the liquid cooling circulation pump based on the second control signal.

[0035] Step S4: After the programmable logic controller is repaired and back online, it re-outputs the first and second control signals. The signal acquisition unit receives the first control signal again and transmits it to the core control unit. It stops outputting the switching signal, and the emergency switching unit stops triggering the core control unit. The core control unit implements PID control of the liquid-cooling circulation pump based on the first control signal. Simultaneously, the communication storage unit receives and stores the second control signal. Specifically, after the programmable logic controller is repaired and back online, the current value at the AI1 terminal increases from less than 3.6mA to 4-20mA, indicating that the first control signal has been restored. PID control of the liquid-cooling circulation pump is then implemented through the continued output of the first control signal. Simultaneously, the second control signal output by the programmable logic controller is transmitted to the pre-stored speed register via the RS485 data synchronization channel for pre-storage.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A control device for a liquid cooling circulation pump, comprising a frequency converter, a liquid cooling circulation pump, and a programmable logic controller, wherein the frequency converter comprises an information acquisition unit and a core control unit, and the programmable logic controller, the information acquisition unit, the core control unit, and the liquid cooling circulation pump are electrically connected in sequence; characterized in that: The frequency converter further includes an emergency switching unit and a communication storage unit. The emergency switching unit is electrically connected to the information acquisition unit and the core control unit respectively. The communication storage unit is electrically connected to the programmable logic controller and the core control unit respectively.

2. The control device for a liquid cooling circulation pump according to claim 1, characterized in that: The programmable logic controller includes an analog output module and a digital output module. The analog output module is electrically connected to the information acquisition unit, and the digital output module is electrically connected to the communication storage unit.

3. The control device for a liquid cooling circulation pump according to claim 2, characterized in that: It also includes a 24V DC power supply, which supplies power to the programmable logic controller and the emergency switching unit; The reference ground of the analog output module, the reference ground of the digital output module and the common ground of the control terminal of the inverter are commonly connected to the negative pole of the 24V DC power supply to form a star single-point grounding network.

4. The control device for a liquid cooling circulation pump according to claim 1, characterized in that: The information acquisition unit includes an information detection circuit and an ACD converter, and the programmable logic controller, the information detection circuit, the ACD converter and the core control unit are electrically connected in sequence.

5. The control device for a liquid cooling circulation pump according to claim 1, characterized in that: The communication storage unit includes a pre-stored speed register, and the pre-stored speed register is electrically connected to the programmable logic controller and the core control unit respectively.

6. The control device for a liquid cooling circulation pump according to claim 1, characterized in that: The emergency switching unit includes an LO control circuit and an LI3 receiving circuit, the information acquisition unit is electrically connected to the LO control circuit, and the LI3 receiving circuit is electrically connected to the core control unit; The LO control circuit includes an LO-terminal, the LI3 receiving circuit includes an LI3 terminal, and the LO-terminal and the LI3 terminal are short-circuited.

7. The control device for a liquid cooling circulation pump according to claim 1, characterized in that: The core control unit includes a control source selector, and the control source selector is electrically connected to the information acquisition unit, the communication storage unit and the emergency switching unit respectively.

8. The control method for a liquid cooling circulation pump according to claim 1, characterized in that: The information acquisition unit includes a fixed first parameter, the first parameter being fixed to a value of 0x0A for enabling analog signal loss detection; The emergency switching unit includes a fixed second parameter and a third parameter. The second parameter is fixed to a value of 0x7B for binding the logic output terminal to a signal loss event. The third parameter is fixed to a value of 0xC3 for configuring a preset speed trigger logic.

9. A control method for a liquid cooling circulation pump, applied to the control device for a liquid cooling circulation pump according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1: When the programmable logic controller operates normally, the programmable logic controller continuously outputs a first control signal and a second control signal. The signal acquisition unit receives the first control signal and transmits it to the core control unit. The core control unit performs PID control on the liquid cooling circulation pump according to the first control signal. At the same time, the communication storage unit receives and stores the second control signal. Step S2: When the programmable logic controller fails, the information acquisition unit detects that the first control signal is lost and outputs a switching signal. The emergency switching unit triggers the core control unit according to the switching signal, causing the core control unit to switch to a state of running at an internal preset speed. Step S3: After the core control unit is switched, the core control unit reads the second control signal stored in the communication storage unit, and controls the frequency of the liquid cooling circulation pump according to the second control signal; Step S4: When the programmable logic controller is repaired and back online, the programmable logic controller re-outputs the first control signal and the second control signal. The signal acquisition unit receives the first control signal again and transmits it to the core control unit, and stops outputting the switching signal. The emergency switching unit stops triggering the core control unit. The core control unit implements PID control on the liquid cooling circulation pump according to the first control signal. At the same time, the communication storage unit receives and stores the second control signal.

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