Airborne liquid cooling pump phase sequence detection method and system

Abstract

The invention belongs to the technical field of aviation electrical detection, and particularly relates to an aviation airborne liquid cooling pump equipment phase sequence detection method, which comprises the following steps: acquiring a three-phase alternating voltage signal input by an airborne liquid cooling pump, and performing isolation amplification processing to obtain line voltages UUV and UWV between U-V and W-V; the UUV voltage and the UWV voltage are analyzed through the main control chip, and UU, UV and UW are obtained; setting a normalization processing threshold value, and converting the sinusoidal signal into a square wave signal; and according to the square wave signal, phase sequence abnormity is judged and protection is carried out. According to the detection method provided by the invention, the number of used components is small, the cost is low, and the reliability is high; threshold setting is flexible; the use scene is wide; the detection accuracy is high; the detection range is wide.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation electrical detection, and in particular relates to a phase sequence detection method for aviation airborne liquid cooling pump equipment. Background Art

[0002] With the development of science and technology, the miniaturization, high density and high integration of electronic components and the heat dissipation problem of high-power equipment have become increasingly prominent. Traditional air cooling and other methods are difficult to adapt to the development needs of electronic equipment. The liquid cooling system solves the cooling problem of high-power and high-heat flux density electronic equipment. The liquid cooling pump is the power mechanism for heat exchange of liquid in the liquid cooling system. Its normal and trouble-free operation is crucial to the function realization of the liquid cooling system.

[0003] The existing motor phase sequence detection equipment cannot realize real-time monitoring and protection during operation. Aiming at the needs of the airborne liquid cooling system during operation, a three-phase phase sequence detection algorithm for the liquid cooling pump is designed to realize online detection and real-time protection of the liquid cooling pump operation process. Summary of the invention

[0004] Purpose of the invention: Based on the requirements for real-time and high reliability of the operation of the liquid cooling pump in the airborne liquid cooling system, a three-phase sequence detection method for the liquid cooling pump is proposed to realize online detection of phase sequence errors and phase loss of the liquid cooling pump, evaluate the status of the liquid cooling pump and provide real-time protection to avoid serious impact on mission execution and flight safety.

[0005] Technical solution: On the one hand, the present invention proposes a phase sequence detection method for an onboard liquid cooling pump. The detection method collects the three-phase AC voltage signal input by the onboard liquid cooling pump, and obtains the line voltage U between UV and WV through isolation and amplification processing. UV and U WV ; Through the main control chip to U UV and U WV The voltage is analyzed to get U U , U V , U W ; Set the normalization processing threshold to convert the sinusoidal signal into a square wave signal; judge the phase sequence abnormality based on the square wave signal and perform protection.

[0006] Furthermore, when the three-phase AC voltage signal input by the onboard liquid cooling pump is collected, one of the phases is used as the reference ground, and the line voltage U between UV and WV is processed through two processing circuits. UV and U WV collection and processing.

[0007] Furthermore, the acquisition and processing process is as follows: define AC-U-IN, AC-V-IN, and AC-W-IN as the input three phases, which are U phase voltage, V phase voltage, and W phase voltage respectively; take V phase voltage as the reference ground, divide the line voltage between UV and WV, and then pass through the isolation amplifier, bias, and amplify it to the voltage range matching the main control chip, and output the analog signal U corresponding to the UV line voltage and the WV line voltage. UV , U WV .

[0008] Furthermore, the main control chip UV and U WV The voltage is analyzed to get U U , U V , U W Voltage, the analysis process is:

[0009] U UV +U VW +U WU =0

[0010] U UV =U U -U V

[0011] U VW =U V -U W

[0012] U WU =U W -U U

[0013] U U +U V +U W =0

[0014] Export:U U =(U UV +U UW ) / 3

[0015] U V =(-U UV -U WV ) / 3

[0016] U W =(-U UW +U WV ) / 3;

[0017] Where U UV is the line voltage between U and V; WV is the line voltage between WV; U UW is the line voltage between UW; U Uis the U phase voltage, U V is the V phase voltage, U W is the W phase voltage.

[0018] Furthermore, the method for setting the normalization threshold is to establish a threshold setting model to obtain the U U , U V , U W , determine the threshold setting based on the ideal normalization processing results.

[0019] On the other hand, the present invention also proposes an onboard liquid cooling pump phase sequence detection system, the system includes a hardware unit and a software unit, the hardware unit is used to collect the three-phase AC voltage signal input by the onboard liquid cooling pump, and obtain the line voltage U between UV and WV through isolation and amplification processing. UV and U WV ; The software unit is based on U UV and U WV As input, the phase sequence fault is determined after analysis, normalization and filtering.

[0020] Furthermore, the hardware unit includes an acquisition circuit module, an isolation circuit module, and an amplification circuit module; the acquisition circuit module is used to acquire the three-phase AC voltage signal input by the onboard liquid cooling pump, and at the same time, the high-voltage signal is reduced once by voltage division; the isolation circuit module is used to isolate the high-voltage part from the low-voltage part in the hardware unit, and at the same time, the high-voltage signal after the primary voltage reduction is amplified for a secondary time and converted into a differential signal, which is an AC signal; the amplification circuit module raises the differential signal voltage through DC bias to realize the conversion of AC signal and DC signal, and at the same time, the converted DC signal is reduced by a certain proportion to convert it into a recognizable voltage range.

[0021] Furthermore, during the phase sequence fault determination process, microsecond level interrupts are enabled for data collection.

[0022] Furthermore, the phase sequence fault includes phase loss, undervoltage, and phase sequence error.

[0023] Technical effect: The detection method proposed by the present invention uses a small number of components, has low cost and high reliability; the threshold setting is flexible; the application scenario is wide; the detection accuracy is high; and the detection range is wide;

[0024] Specifically, compared with the traditional circuit form of using two independent circuits to collect three voltage amplitudes and three voltage phase sequences, which requires rectifying the three-phase voltage and performing optical coupling isolation to convert the three-phase voltage phase sequence into a frequency signal, the circuit design of the present invention uses a conditioning circuit to simultaneously extract the two-phase line voltage amplitudes between the three-phase voltage signals and the phase sequence information between the three-phase voltage signals from the three-phase voltage analog quantity, and uses a method for judging by software. There are two advantages: one is that it can solve the high-frequency interference problem caused by rectification; the other is that it can save precious PCB space and precious CPU I / O ports, use a small number of components, low cost, and high reliability; in addition, since the detection threshold can be set by software, the same set of hardware has a wider application range and a higher detection accuracy range. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a phase sequence fault detection flow chart;

[0026] Figure 2 This is the phase sequence detection principle diagram;

[0027] Figure 3 It is the analytical principle formula of phase voltage;

[0028] Figure 4 It is a simulation model diagram of the present invention;

[0029] Figure 5 for Figure 4 Scope1 in the model;

[0030] Figure 6 for Figure 4 Scope2 in the model;

[0031] Figure 7 for Figure 4 Scope3 in the model;

[0032] Figure 8 for Figure 4 Scope4 in the model;

[0033] Fig. 9 for Figure 4 Scope6 in the model;

[0034] Fig.10 It is the simulation model of missing U phase;

[0035] Fig.11 Scope6 corresponding to the missing U;

[0036] Fig.12 It is the simulation model of missing V phase;

[0037] Fig.13Scope6 corresponding to the lack of V;

[0038] Fig.14 It is the simulation model of missing W phase;

[0039] Fig.15 for Fig.10 Scope1 corresponding to the model;

[0040] Fig.16 for Fig.10 Scope2 corresponding to the model;

[0041] Fig.17 for Fig.10 Scope3 corresponding to the model;

[0042] Fig.18 for Fig.10 Scope4 corresponding to the model;

[0043] Fig.19 for Fig.10 Scope6 corresponding to the model;

[0044] Fig. 20 Scope 6 with W phase amplitude of 50V;

[0045] Fig.21 This is a schematic diagram of phase sequence error;

[0046] Fig. 22 This is a three-term voltage square wave diagram. DETAILED DESCRIPTION

[0047] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the present invention is described in detail below in conjunction with the drawings or specific implementation cases of the specification. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described and these examples should not be understood as being limited to the examples set forth herein. On the contrary, these examples are described so that the positive effects of the present invention are more reflected, and any parts not detailed in the text are regarded as known techniques or conventional technical means in the art.

[0048] The overall design concept of the phase sequence detection method proposed in the present invention is: to collect the three-phase AC voltage through hardware, and obtain U through hardware circuit processing. UV Phase and U WV The voltage enters the CPU, and the software collects the U UV and U WV The voltage is analyzed to get U U , U V , U W, the threshold of line voltage normalization is obtained through simulation, and the phase sequence abnormality (phase loss, undervoltage, phase sequence error) is judged and protected according to the result after normalization. The following describes the detection process of the present invention in detail in combination with the specific phase sequence abnormality;

[0049] like Figure 1 As shown in the figure, the phase sequence fault detection flow chart is mainly composed of two parts: hardware and software. The main function of the hardware part is to collect the external three-phase voltage, extract the 0-3V voltage signals UV_sensor and WV_sensor recognized by the ADC and send them to the ADC port of the microcontroller. Then the software collects, solves and normalizes the signals through interrupts, and finally makes fault judgment and performs protection.

[0050] The specific implementation path of the hardware part is as follows: acquisition-isolation-amplification. The specific method is as follows: In order to completely retain the two-phase line voltage amplitudes between the three-phase voltage signals and the phase sequence information between the three-phase voltage signals without distortion during the conversion process, and transmit the voltage signals between the three phases to the ADC port without distortion, by setting the V phase voltage among the three phases U, V, and W as the reference voltage, that is, connecting AC-V-IN to the reference ground GND, respectively setting voltage divider resistors R1, R4, R6 and R2, R3, R5 between the two phases UV and WV, and extracting the line voltage analog values ​​UV_LINE and WV_LINE between UV and WV through the voltage divider values ​​of the voltage divider resistors R6 and R5. Then it is isolated and amplified 8.2 times by isolation amplifiers U1 and U4 respectively, and the line voltage analog quantities UV_LINE and WV_LINE between UV and WV are converted into regulated weak current differential signals without distortion, that is, the differential voltage between VOUT+ and VOUT- of U1 and U4, and then passed through a 1 / 2 times in-phase proportional amplifier circuit composed of resistors R7, R9 and resistors R12, R19 (resistors R13, R14 and resistors R16, R15). The overall amplitude is reduced by 0.5 times, and the signal phase remains unchanged. It is then conditioned by a 1.67V DC bias at the subsequent stage into 0-3V voltage signals UV_sensor and WV_sensor that can be recognized by ADC and sent to the ADC port of the microcontroller. Finally, the UV_sensor and WV_sensor signals contain both the two-phase line voltage amplitude information and the phase sequence information between the three-phase voltage signals.

[0051] The implementation path of the software part is as follows: interrupt acquisition - solution - normalization processing - fault determination. The specific method is as follows: Since the three-phase signal is a 400Hz sine signal, the software interrupt acquisition cycle is 40us. Through interrupt acquisition, the analog signal is converted into a discrete signal to obtain UV and WV in the range of [0,4096], completing the interrupt acquisition; based on Figure 2 The circuit principle shown and Figure 3The derivation mechanism shown is analyzed to obtain U U , U V , U W The calculation process is based on the DC sine UV and WV collected by the ADC port, and the DC bias added in the hardware circuit is processed, and the discrete signal value 2280.1 corresponding to the DC bias of 1.67V is subtracted to obtain U UV and U WV , then based on Figure 3 Calculate the formula shown in the figure to get U U =(U UV +U UW ) / 3;

[0052] U V =(-U UV -U WV ) / 3; U W =(-U UW +U WV ) / 3; U U , U V , U W It is a discrete AC sinusoidal signal. By setting the threshold value for normalization, a square wave signal is obtained. The threshold setting simulation process is as follows:

[0053] Build a software algorithm simulation model according to the principle, such as Figure 4 As shown, the source U, V, W, set the amplitude to 162, set the phase to 0, -2*pi / 3, -4*pi / 3 respectively, use the analog oscilloscope Scope1 to display the three-phase sum of U, V, W, use the analog oscilloscope Scope2 to display the three-phase signals of U, V, W respectively; get UV and WV entering the ADC through addition and subtraction operations, use the analog oscilloscope Scope3 to display U UV and U WV ; then based on Figure 3 The principle shown is deduced to obtain U U , U V , U W , use the analog oscilloscope Scope4 to show U U , U V , U W , in U U , U V , U W A comparator is added at the back end, and a numerical value is set for comparison to obtain a normalized square wave signal. The square wave signal is judged based on the phase relationship shown in the figure.

[0054] Take the normal phase sequence as an example: set Figure 4The amplitude of U, V, and W in the simulation model shown is 162, and the phase is set to 0, -2*pi / 3, and -4*pi / 3 respectively. The frequency is 400Hz. The simulation is run, and Scope1 is as follows Figure 5 As shown, the sum of the three items is 0; Scope2 is Figure 6 As shown, U, V, and W are sinusoidal signals with a value of 162, a phase difference of 2*pi / 3, and a frequency of 400Hz; UV and WV signals are as follows Figure 7 As shown, the simulated signal entering the ADC port; the analyzed U U , U V , U W like Figure 8 As shown, by comparison, it can be found that Figure 2 As shown in the figure; setting the threshold to 60, the normalized square wave signal can be obtained as follows Fig. 9 ;

[0055] Taking the phase loss as an example, set the phase loss U, V, and W in the simulation model respectively. Fig.10 , Fig.12 , Fig.14 As shown in the figure, the normalized square wave signal is Fig.11 , Fig.13 , Fig.19 Taking the missing W phase as an example, according to the circuit principle, the missing phase is set to be suspended in the simulation. After the phase is missing, the sum of the three items is not 0. The waveform of the three items is as follows Fig.15 As shown, the three waveforms are as follows Fig.16 As shown, UV and WV are Fig.17 As shown, the amplitude is no longer balanced; the analyzed U U , U V , U W like Fig.18 As shown, the missing phase U W The amplitude resolution is about 55. In order to avoid false alarms and detect sensitively, the threshold is set to 60. The waveform after normalization is as follows Fig.19 , can accurately detect the content of missing phase.

[0056] Taking W phase undervoltage as an example, set the W amplitude to 50V, run the simulation, and the normalized square wave graph is shown in Fig.21 , it is determined that the phase sequence of phase W is abnormal;

[0057] Taking phase sequence error as an example, set the phase of U phase to 0, the phase of V phase to 2*pi / 3, the phase of W phase to 4*pi / 3, and the threshold to 60. The square wave waveform after normalization is shown in Fig. 22 , it can be determined that the phase sequence is wrong.

[0058] The innovative design of the present invention is at least embodied in the following aspects:

[0059] Core design point: The two-phase (UV, WV) voltage values ​​are collected through software, and the three-phase analog values ​​are parsed through CLARK transformation. The phase sequence fault state of the liquid cooling pump is determined and protection is performed by evaluating the three parsed analog values.

[0060] Secondary design point 1: The process of the liquid cooling pump phase sequence detection algorithm: First, collect the real-time voltage data of the UV phase and WV phase of the liquid cooling pump (which can be realized by hardware during the specific implementation process), transform it to obtain the line voltage, and then determine the amplitude through software and perform normalization processing. Finally, according to the phase sequence model, determine whether the phase sequence of the liquid cooling pump is in a fault state (which can be realized by software during the specific implementation process). The detection process is as follows Figure 1 shown.

[0061] Secondary design point 2: The hardware circuit of this detection method includes: acquisition module, isolation module, amplification module, and data processing module. The schematic diagram is shown in Figure 2 As shown; AC-U-IN, AC-V-IN, AC-W-IN are the three input phases, which are U phase voltage, V phase voltage and W phase voltage respectively; AC-V-IN (V phase voltage) is used as the reference ground, and the line voltage between UV and WV is divided and then passed through the isolation amplifier, biased, and amplified to the voltage range of 0 to 3V before inputting into the ADC port. The analog signal of the UV line voltage after the above conditioning is UV_sensor, and the analog signal of the WV line voltage after the above conditioning is WV_sensor. In order to reduce the interference of line voltage acquisition, the voltage division is also designed between the UW lines to balance the load between the three phases.

[0062] Secondary design point 3: Setting of acquisition and calculation cycle. For 115V / 400Hz data, the determination of acquisition and data processing cycle puts forward requirements for the computing power and data throughput of the controller.

[0063] Secondary design point 4: U UV , U WV The voltage of U is obtained by analysis. U , U V , U W Voltage, formula as Figure 3 As shown;

[0064] Secondary design point 5: Threshold setting. The threshold of normalization processing is determined through simulation and normalization processing is performed. The simulation model is shown in Figure 4 .

[0065] Secondary design point 6: Based on the normalized values ​​and combined with the three-phase voltage model, the phase sequence fault is evaluated and real-time alarm and protection are performed.

[0066] The above specific implementation methods or cases are only used to explain the technical solutions of the present invention, and are not intended to limit the present application. Any parts not described in detail are deemed to be conventional technical means or common knowledge in the field. It can be understood by ordinary technicians in this field that: based on the design concept of the present application, the technical solutions recorded in the aforementioned implementation methods should be adaptively modified, or some or all of the technical features therein should be replaced by equivalents. These modifications, equivalent replacements, and adaptively improved technical solutions do not depart from the technical essence of the present invention and should all be covered within the protection scope of the present application.

Claims

1. A method for detecting phase sequence of an airborne liquid cooling pump, characterized in that: The detection method collects the three-phase AC voltage signal input by the onboard liquid cooling pump, and obtains the line voltage U between UV and WV through isolation and amplification. UV and U WV ; Through the main control chip to U UV and U WV The voltage is analyzed to get U U , U V , U W ; Set the normalization processing threshold to convert the sinusoidal signal into a square wave signal; judge the phase sequence abnormality based on the square wave signal and perform protection.

2. The method for detecting the phase sequence of an onboard liquid cooling pump according to claim 1, characterized in that: When collecting the three-phase AC voltage signal input by the onboard liquid cooling pump, one of the phases is used as the reference ground, and the line voltage U between UV and WV is processed through two processing circuits. UV and U WV collection and processing.

3. The method for detecting the phase sequence of an onboard liquid cooling pump according to claim 2, characterized in that: The acquisition and processing process is as follows: define AC-U-IN, AC-V-IN, and AC-W-IN as the input three phases, which are U phase voltage, V phase voltage, and W phase voltage respectively; take V phase voltage as the reference ground, divide the line voltage between UV and WV, and then pass through the isolation amplifier, bias, and amplify it to the voltage range matching the main control chip, and output the analog signal U corresponding to the UV line voltage and the WV line voltage. UV , U WV .

4. The method for detecting the phase sequence of an onboard liquid cooling pump according to claim 3, characterized in that: Main control chip for U UV and U WV The voltage is analyzed to get U U , U V , U W Voltage, the analysis process is: IN UV +U VW +U WU =0 IN UV =U U -IN V IN VW =U V -IN W IN WU =U W -IN U IN U +U V +U W =0 Start: U U =(U UV +U UW ) / 3 IN V =(-U UV -IN WV ) / 3 IN W =(-U UW +U WV ) / 3; Where U UV is the line voltage between U and V; WV is the line voltage between WV; U UW is the line voltage between UW; U U is the U phase voltage, U V is the V phase voltage, U W is the W phase voltage.

5. The method for detecting the phase sequence of an onboard liquid cooling pump according to claim 1, characterized in that: The method for setting the normalization threshold is as follows: establishing a threshold setting model to obtain the U U , U V , U W , determine the threshold setting based on the ideal normalization processing results.

6. An onboard liquid cooling pump phase sequence detection system, used to implement the detection method according to any one of claims 1 to 5, characterized in that: The system includes a hardware unit and a software unit. The hardware unit is used to collect the three-phase AC voltage signal input by the onboard liquid cooling pump, and obtain the line voltage U between UV and WV through isolation and amplification processing. UV and U WV ; The software unit is based on U UV and U WV As input, the phase sequence fault is determined after analysis, normalization and filtering.

7. The airborne liquid cooling pump phase sequence detection system according to claim 6, characterized in that: The hardware unit includes an acquisition circuit module, an isolation circuit module, and an amplification circuit module; the acquisition circuit module is used to acquire the three-phase AC voltage signal input by the onboard liquid cooling pump, and at the same time, the high-voltage signal is reduced once by voltage division; the isolation circuit module is used to isolate the high-voltage part from the low-voltage part in the hardware unit, and at the same time, the high-voltage signal after the primary voltage reduction is amplified for a second time and converted into a differential signal, which is an AC signal; the amplification circuit module raises the differential signal voltage through DC bias to realize the conversion of AC signal and DC signal, and at the same time, the converted DC signal is reduced by a certain proportion to convert it into a recognizable voltage range.

8. The airborne liquid cooling pump phase sequence detection system according to claim 7, characterized in that: During the phase sequence fault judgment process, microsecond interrupts are enabled for data collection.

9. The airborne liquid cooling pump phase sequence detection system according to claim 8, characterized in that: Phase sequence faults include phase loss, undervoltage, and phase sequence error.

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