High-speed rotating temperature transmitter, temperature acquisition method and rotor temperature monitoring system

Abstract

The application relates to a high-speed rotating temperature transmitter, a temperature acquisition method and a rotor temperature monitoring system, wherein the high-speed rotating temperature transmitter comprises a separate transformer, a first processing unit and a second processing unit; the separate transformer comprises a primary coil and a secondary coil which are coupled to each other; the first processing unit is connected to an external power supply through a signal conditioner; the first processing unit is used for driving the primary coil to generate an alternating magnetic field so that the secondary coil forms an alternating electromotive force; the second processing unit is connected with a plurality of temperature sampling sensors; the second processing unit generates an impedance change signal reflecting temperature signal data; the secondary coil sends the impedance change signal to the first processing unit through electromagnetic induction mode; and the signal conditioner extracts the impedance change signal and processes the impedance change signal into a current signal reflecting the temperature signal data. The application has higher measurement precision, better measurement effect, simpler overall circuit structure and lower cost.

Description

Technical Field

[0001] This invention relates to the field of temperature detection device technology, and in particular to a high-speed rotating temperature transmitter, a temperature acquisition method, and a rotor temperature monitoring system. Background Technology

[0002] Currently, electric motors account for up to 50% of my country's total electricity consumption and nearly 70% of industrial electricity consumption. Reducing electric motor energy consumption has become an urgent task. High-efficiency energy-saving permanent magnet motors have been widely promoted and applied due to their significant energy-saving effects, improving efficiency by about 5%-10%. The "Electric Motor Energy Efficiency Improvement Plan (2021-2023)" jointly issued by the Ministry of Industry and Information Technology and the State Administration for Market Regulation proposes that by 2023, the annual output of high-efficiency energy-saving motors will reach 170 million kilowatts, with high-efficiency energy-saving motors accounting for more than 20% of the total in-service capacity, achieving annual electricity savings of 49 billion kilowatt-hours, equivalent to saving 15 million tons of standard coal and reducing carbon dioxide emissions by 28 million tons annually.

[0003] Rare-earth permanent magnets on the rotor of a high-efficiency permanent magnet motor are key components for its functionality. Long-term overload, frequent start-stop, and unreasonable drive parameter settings can easily cause high-temperature demagnetization. Once the permanent magnets demagnetize, the process is irreversible, and over time, it will cause the entire motor rotor to be scrapped. Therefore, real-time monitoring of the temperature of the electronic rotor is very important.

[0004] Rotary temperature transmitters are suitable for measuring and transmitting temperatures of rotating components. They transmit temperature signals via electromagnetic induction, then convert the signals into a standard 4-20mA current for temperature control. They utilize non-contact power transmission technology for power supply and infrared communication technology for data feedback. Traditional rotary temperature transmitters typically use a separate transformer to power the rotor side. For data feedback, after the rotor-side circuit is operational, the sensor signal is converted to a frequency signal via voltage-to-frequency conversion and fed back to the transmitter via radio electromagnetic waves. This method is prone to interference from the power supply magnetic field and the rotor's wireless magnetic field. Alternatively, infrared technology, which does not interfere with electromagnetic fields, can be used to transmit the rotor-side signal to the transmitter side. However, this requires additional infrared transmitters and receivers, increasing hardware costs and circuit complexity, resulting in higher overall costs. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a high-speed rotary temperature transmitter, a temperature acquisition method, and a rotor temperature monitoring system to solve the technical problems of rotary temperature transmitters being susceptible to interference, having complex circuits, and being costly in the prior art.

[0006] To achieve the above and other related objectives, the present invention provides the following technical solution:

[0007] A high-speed rotary temperature transmitter, comprising:

[0008] A split transformer, comprising a primary winding and a secondary winding coupled to each other, wherein the primary winding is disposed on the stator side of the motor and the secondary winding is disposed on the rotor side of the motor;

[0009] A first processing unit connected to the primary coil, the first processing unit being connected to an external power supply via a signal conditioner, the first processing unit being used to drive the primary coil to generate an alternating magnetic field so that the secondary coil is induced to form an alternating electromotive force;

[0010] A second processing unit is connected to the secondary coil. The second processing unit is connected to several temperature sampling sensors. The temperature sampling sensors are used to sample the temperature signal of the motor rotor in real time. The second processing unit responds to the temperature signal to generate an impedance change signal that reflects the temperature signal data. The secondary coil sends the signal to the first processing unit through the primary coil via electromagnetic induction. The signal conditioner extracts the impedance change signal and conditions it into a current signal that reflects the temperature signal data.

[0011] To implement the above technical solution, in use, the primary winding of the split transformer and the first processing unit are located on the stator side of the motor, while the secondary winding and the second processing unit are located on the rotor side. A signal conditioner is connected to an external power supply, typically a DC power supply. The signal conditioner can condition this external power supply to meet the requirements of the split transformer and the first processing unit. When the first processing unit operates, it drives the primary winding to generate an alternating magnetic field, causing the secondary winding to induce an alternating electromotive force, thus powering the second processing unit and loads such as the temperature sampling sensor. The temperature sampling sensor is connected to the motor rotor and can collect the rotor temperature in real time, generating a temperature signal. Upon receiving this temperature signal, the second processing unit generates an impedance change signal. The impedance change signal can reflect the temperature signal data. At this time, the secondary coil transmits the impedance change signal to the first processing unit through electromagnetic induction, and finally to the signal conditioner. The signal conditioner extracts the temperature signal from the impedance change signal, processes it, and modulates it into a current signal suitable for subsequent processing, thereby realizing the real-time acquisition and transmission of the motor rotor temperature signal. Since the rotor-side circuit is powered by induced electromotive force, and the temperature signal is transmitted by electromagnetic induction by changing the current amplitude through impedance transformation, the two do not interfere with each other, resulting in higher measurement accuracy, better measurement effect, and a simpler overall circuit structure. No additional receiving and transmitting devices are required, resulting in lower cost.

[0012] As a preferred embodiment of the invention, the second processing unit includes:

[0013] A rectifier and filter circuit connected to the secondary coil;

[0014] An equivalent impedance changing switch circuit connected to the rectifier filter circuit is used to sense temperature signals to change the input resistance value and generate an impedance change signal.

[0015] A second voltage regulator circuit is connected to the equivalent impedance change switching circuit. The second voltage regulator circuit is used to regulate the alternating electromotive force to provide a stable voltage source to the load.

[0016] A temperature acquisition circuit connected to the second voltage regulator circuit, wherein the temperature acquisition circuit is connected to the temperature sampling sensor for acquiring temperature signals;

[0017] A second microcontroller module is connected to the temperature acquisition circuit, and the second microcontroller module is connected to the second voltage regulator circuit and the equivalent impedance change switch circuit.

[0018] To achieve the above technical solution, during power supply, the secondary coil induces an alternating electromotive force, which is then rectified and filtered by a rectifier and filter circuit, and then regulated by a voltage regulator circuit to provide stable power to the second microcontroller module, temperature acquisition circuit, and temperature sampling sensor. After the temperature sampling sensor acquires a temperature signal, the temperature acquisition circuit obtains the corresponding temperature signal and sends it to the second microcontroller module for processing. The signal is then sent to the equivalent impedance changing switch circuit. Upon receiving the signal, the equivalent impedance changing switch circuit changes the input resistance value to generate an impedance change signal, which is then sent from the secondary coil to the primary coil via electromagnetic induction, thereby realizing the acquisition and transmission of the temperature signal.

[0019] As a preferred embodiment of the invention, the temperature acquisition circuit includes: a temperature sampling chip and a sampling analog circuit connected to the temperature sampling chip. The sampling analog circuit includes a plurality of sampling branches corresponding to each of the temperature sampling sensors, and each of the sampling branches is connected to the temperature sampling chip through a low-pass filter.

[0020] To achieve the above technical solution, a constant current source is provided by a temperature sampling chip. After the temperature sampling sensor collects the temperature signal, it is converted into a voltage signal. After passing through a low-pass filter, high-frequency interference can be effectively suppressed. Each sampling branch can transmit the signal collected by each temperature sampling sensor to the temperature sampling chip, and then the temperature sampling chip performs the corresponding processing to complete the temperature sampling process.

[0021] As a preferred embodiment of the invention, the equivalent impedance change switching circuit includes: a field-effect transistor connected to the second microcontroller module, and a current-limiting resistor connected to the field-effect transistor. The field-effect transistor turns on in response to a temperature signal to connect to the current-limiting resistor, thereby generating the impedance change signal.

[0022] To achieve the above technical solution, the current limiting circuit is connected to or disconnected by turning the field-effect transistor on and off, thereby changing the equivalent resistance value in the circuit and thus changing the current amplitude, which in turn generates an impedance change signal.

[0023] As a preferred embodiment of the invention, the first processing unit includes:

[0024] A first voltage regulator circuit connected to the signal conditioner;

[0025] A first microcontroller module connected to the first voltage regulator circuit; and,

[0026] An H-bridge driver connected to the first microcontroller module, the H-bridge driver being connected to the primary coil and the signal conditioner, is used to invert DC power into a variable frequency AC circuit to supply the primary coil so that the discrete transformer outputs a predetermined voltage value.

[0027] To achieve the above technical solution, the voltage source fed into the signal conditioner is regulated by the first voltage regulator circuit, thereby providing a stable power supply to the first microcontroller module. Then, the H-bridge driver inverts the DC power supply into a variable frequency AC circuit to supply the primary coil, so that the voltage output on the secondary coil side is only related to the turns ratio of the primary and secondary coils. Thus, after selecting a suitable turns ratio, a predetermined voltage value can be output.

[0028] As a preferred embodiment of the invention, the signal conditioner includes:

[0029] An analog power supply circuit that is connected to an external power source;

[0030] A digital power supply circuit that is connected to an external power source;

[0031] A current sampling circuit connected to the first processing unit is used to acquire the current signal fed back by the second processing unit to extract the temperature signal;

[0032] A filter amplifier circuit connected to the current sampling circuit;

[0033] A main control microcontroller is connected to the filter amplifier circuit, and the main control microcontroller is connected to the digital power supply circuit;

[0034] A digital isolation circuit connected to the main control microcontroller, the digital isolation circuit being connected to both the analog power supply circuit and the digital power supply circuit; and,

[0035] A DA converter connected to the digital isolation circuit, the DA converter being connected to the analog power supply circuit.

[0036] To achieve the above technical solution, different power supply requirements can be met by using analog power supply circuits and digital power supply circuits. The current signal output by the first processing unit is received by the current sampling circuit, and the current signal is amplified by the filtering and amplification circuit. After the main control unit performs calculations, the corresponding temperature signal data is obtained, and the corresponding current value is output and written into the DA converter to complete the transmission of the temperature signal.

[0037] As a preferred embodiment of the invention, the current sampling circuit includes:

[0038] Connection interface for connecting to an external power source;

[0039] A sampling diode with its anode connected to the connection interface and its cathode grounded is provided. The anode of the sampling diode is connected to the filter amplifier circuit through a sampling resistor.

[0040] To achieve the above technical solution, since the signal conditioner is usually far from the motor, it can be connected to the first processing unit via a long wire through the connection interface. In order to extract the temperature signal from the current signal, the voltage signal across the two ends of the series resistor is generally used, that is, the current signal is converted into a voltage signal. Since it is only necessary to detect the change in current amplitude when extracting the temperature signal, and not the magnitude of the change, a sampling diode is used to replace the existing sampling resistor. The voltage value across its two ends can change with the current flowing through it, thus realizing the current sampling process.

[0041] As a preferred embodiment of the invention, the filter amplification circuit includes: a filter chip connected to the current sampling circuit, and an amplification circuit module connected to the filter chip, wherein the amplification circuit module includes a plurality of connected amplifiers.

[0042] To achieve the above technical solution, the signal obtained by the current sampling circuit can be extracted by the filter chip and then amplified by the amplifier circuit module, making the signal easier to identify.

[0043] On the other hand, to solve the above-mentioned technical problems, embodiments of the present invention also provide a temperature acquisition method, the temperature acquisition method being based on the high-speed rotating temperature transmitter described in any of the above technical solutions, comprising:

[0044] The first processing unit receives a power signal input from a signal conditioner to drive the primary coil to generate an alternating magnetic field, thereby inducing an alternating electromotive force in the secondary coil to supply power to the load.

[0045] The second processing unit generates an impedance change signal that reflects the temperature signal data based on the temperature signal obtained by the temperature sampling sensor, so that the secondary coil sends the signal to the first processing unit through the primary coil via electromagnetic induction, and the impedance change signal is extracted by the signal conditioner to be conditioned into a current signal that reflects the temperature signal data.

[0046] The above technical solution uses induced electromotive force to power the rotor-side circuit, and transmits the temperature signal by electromagnetic induction by changing the current amplitude through impedance transformation to generate an impedance change signal. Therefore, the two do not interfere with each other, resulting in higher measurement accuracy, better measurement effect, and a simpler overall circuit structure. No additional receiving and transmitting devices are required, leading to lower cost.

[0047] On the other hand, to solve the above-mentioned technical problems, embodiments of the present invention also provide a rotor temperature monitoring system, including:

[0048] The high-speed rotary temperature transmitter as described in any of the above technical solutions; and...

[0049] A temperature control cabinet is connected to the output terminal of the signal conditioner. The temperature control cabinet is used to adjust the working state of the motor based on the temperature signal data obtained by the high-speed rotating temperature transmitter.

[0050] To achieve the above technical solution, the temperature signal is collected by a high-speed rotating temperature transmitter and then transmitted to the temperature control cabinet. The temperature control cabinet monitors the temperature in real time and can perform functions such as alarm and motor operation adjustment based on the temperature signal. This can prevent the permanent magnet from being demagnetized in time when the temperature is too high and reduce motor damage.

[0051] As described above, the present invention has the following beneficial effects:

[0052] This invention provides a high-speed rotating temperature transmitter, a temperature acquisition method, and a rotor temperature monitoring system. In use, the primary winding of the split transformer and the first processing unit are located on the stator side of the motor, while the secondary winding and the second processing unit are located on the rotor side. A signal conditioner is connected to an external power supply, typically a DC power supply. The signal conditioner can condition this external power supply to meet the requirements of the split transformer and the first processing unit. When the first processing unit operates, it drives the primary winding to generate an alternating magnetic field, which induces an alternating electromotive force in the secondary winding, thus powering the second processing unit and the temperature sampling sensor. The temperature sampling sensor is connected to the motor rotor and can acquire the rotor temperature in real time, generating a temperature signal. The second processing unit receives this temperature signal. The signal generates an impedance change signal, which reflects the temperature signal data. At this time, the secondary coil transmits the impedance change signal to the first processing unit through electromagnetic induction, and finally to the signal conditioner. The signal conditioner extracts the temperature signal from the impedance change signal, processes it, and conditions it into a current signal suitable for subsequent processing, thereby realizing the real-time acquisition and transmission of the motor rotor temperature signal. Since the rotor-side circuit is powered by induced electromotive force, and the temperature signal is transmitted by electromagnetic induction by changing the current amplitude through impedance transformation, the two do not interfere with each other, resulting in higher measurement accuracy, better measurement effect, and a simpler overall circuit structure. No additional receiving and transmitting devices are required, resulting in lower cost. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 The diagram shown is a circuit schematic of Embodiment 1 of the present invention.

[0055] Figure 2 The diagram shown is a circuit schematic for generating an impedance change signal in Embodiment 1 of the present invention.

[0056] Figure 3 The diagram shows the waveform changes of the signal during data transmission in Embodiment 1 of the present invention.

[0057] Figure 4 The diagram shown is a circuit schematic of Embodiment 2 of the present invention.

[0058] Figure 5 The diagram shown is a schematic diagram of the sampling analog circuit in Embodiment 2 of the present invention.

[0059] Figure 6 The diagram shown is a circuit schematic of the temperature sampling chip in Embodiment 2 of the present invention.

[0060] Figure 7 The diagram shown is a circuit schematic of the second microcontroller module in Embodiment 2 of the present invention.

[0061] Figure 8 The diagram shown is a circuit schematic of an equivalent impedance changing switching circuit according to Embodiment 2 of the present invention.

[0062] Figure 9 The diagram shown is a schematic diagram of the first voltage regulator circuit in Embodiment 2 of the present invention.

[0063] Figure 10 The diagram shown is a circuit schematic of the first microcontroller module in Embodiment 2 of the present invention.

[0064] Figure 11 The diagram shown is a circuit schematic of the H-bridge driver in Embodiment 2 of the present invention.

[0065] Figure 12 The diagram shown is the equivalent circuit diagram of the H-bridge driver in Embodiment 2 of the present invention.

[0066] Figure 13 The diagram shown is a circuit schematic of the signal conditioner in Embodiment 2 of the present invention.

[0067] Figure 14 The diagram shown is a circuit schematic of the digital circuit power supply in Embodiment 2 of the present invention.

[0068] Figure 15 The diagram shown is a schematic diagram of the analog circuit power supply in Embodiment 2 of the present invention.

[0069] Figure 16 The diagram shown is a schematic diagram of the current sampling circuit in Embodiment 2 of the present invention.

[0070] Figure 17 The diagram shown is a schematic of the filter amplifier circuit in Embodiment 2 of the present invention.

[0071] Figure 18 The diagram shown is a circuit schematic of the digital isolated power supply in Embodiment 2 of the present invention.

[0072] Figure 19 The diagram shown is a circuit schematic of the DA converter in Embodiment 2 of the present invention. Detailed Implementation

[0073] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0074] Please see Figures 1 to 19 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0075] Example 1

[0076] Please see Figure 1 and Figure 2 This invention provides a high-speed rotating temperature transmitter, comprising: a split transformer, the split transformer including a primary coil and a secondary coil coupled to each other, the primary coil being disposed on the stator side of a motor and the secondary coil being disposed on the rotor side of a motor; a first processing unit connected to the primary coil, the first processing unit being connected to an external power supply through a signal conditioner, the first processing unit being used to drive the primary coil to generate an alternating magnetic field to induce an alternating electromotive force in the secondary coil; and a second processing unit connected to the secondary coil, the second processing unit being connected to a plurality of temperature sampling sensors, the temperature sampling sensors being used to sample the temperature signal of the motor rotor in real time, the second processing unit responding to the temperature signal to generate an impedance change signal reflecting the temperature signal data, causing the secondary coil to transmit the signal to the first processing unit via the primary coil through electromagnetic induction; and the signal conditioner extracting the impedance change signal and conditioning it into a current signal reflecting the temperature signal data.

[0077] Specifically, there is a special medium such as an air gap or water between the primary and secondary coils of the split transformer. Through the principle of electromagnetic coupling induction, an alternating electromotive force can be generated to achieve non-contact power transmission. The first processing unit can convert ordinary power supply into high-frequency AC power supply that can be used by the primary coil of the split transformer, while the second processing unit can perform AC conversion on the secondary coil of the split transformer to facilitate load use.

[0078] like Figure 2 As shown, Figure 2The circuit diagram for generating an impedance change signal is shown. The primary coil, the first processing unit, and the signal conditioner constitute the stator-side circuit, while the secondary coil and the second processing unit constitute the rotor-side circuit. The second processing unit sends the collected temperature signal data to the microcontroller minimum system. This microcontroller minimum system can be understood as a control chip within the microcontroller. After processing, the temperature signal data controls the switching transistor VT2, thereby connecting or disconnecting the resistor connected in series with VT2, thus causing the rotor to... The change in the equivalent impedance on the rotor side causes a change in the current amplitude flowing through the secondary coil on the rotor side, and the load on the split transformer changes. Through the induced coupling between the primary and secondary coils of the split transformer, the current amplitude flowing through the primary coil on the stator side also changes, that is, the load on the stator changes. This allows the temperature signal to be transmitted to the stator side of the split transmitter through the current. The impedance change signal is extracted by filtering in the primary coil of the split transformer, and finally conditioned by the first processing unit and the signal conditioner into a standard 4-20mA current signal.

[0079] The modulation characteristics of the signal transmission process are as follows:

[0080] (1) When the binary data is encoded as “0”, negative logic is used, the microcontroller minimum system outputs a high level, the switching transistor is turned on, and the current flows through the branch where the switching transistor is located.

[0081] (2) The equivalent impedance on the rotor side decreases, the load on the split transformer increases, and thus the amplitude of the current flowing through the secondary coil on the rotor side of the split transformer also increases.

[0082] (3) Through the coupling between the primary and secondary coils of the split transformer, the change in current amplitude is transmitted to the primary coil on the stator side, and the current amplitude of the primary coil also increases, and the load on the stator side of the split transmitter also increases.

[0083] (4) The stator side is connected to the adapter box via a wire. The current flowing through the long wire carries the data signal. The wire on the signal conditioner side is connected to a sampling diode. The temperature signal in the current is detected by the voltage on the sampling diode. The signal is read by the demodulation work of the subsequent adapter box circuit using negative logic to complete the data transmission of the temperature signal and read the data "1".

[0084] The table below shows the correspondence between various physical quantities in the data transmission process:

[0085]

[0086] In use, the primary winding of the split transformer and the first processing unit are located on the stator side of the motor, while the secondary winding and the second processing unit are located on the rotor side. A signal conditioner is connected to an external power supply, typically a DC power supply. The signal conditioner conditions this external power supply to meet the requirements of the split transformer and the first processing unit. When the first processing unit operates, it drives the primary winding to generate an alternating magnetic field, which induces an alternating electromotive force in the secondary winding, thus powering the second processing unit and loads such as the temperature sampling sensor. The temperature sampling sensor is connected to the motor rotor and can collect the rotor temperature in real time, generating a temperature signal. Upon receiving this temperature signal, the second processing unit generates an impedance change signal. The signal can reflect temperature signal data. At this time, the secondary coil sends the impedance change signal to the first processing unit through electromagnetic induction. Finally, it is transmitted to the signal conditioner, which extracts the temperature signal from the impedance change signal, processes it, and modulates it into a current signal suitable for subsequent processing, thereby realizing the real-time acquisition and transmission of the motor rotor temperature signal. Since the rotor-side circuit is powered by induced electromotive force, and the temperature signal is sent by electromagnetic induction by changing the current amplitude through impedance transformation, the two do not interfere with each other, resulting in higher measurement accuracy, better measurement effect, and a simpler overall circuit structure. No additional receiving and transmitting devices are required, resulting in lower cost.

[0087] Example 2

[0088] The difference between this embodiment and Embodiment 1 is that: in this embodiment, as Figure 4 As shown, the second processing unit includes: a rectifier and filter circuit connected to the secondary coil; an equivalent impedance changing switch circuit connected to the rectifier and filter circuit, the equivalent impedance changing switch circuit being used to sense temperature signals to change the input resistance value and generate impedance changing signals; a second voltage regulator circuit connected to the equivalent impedance changing switch circuit, the second voltage regulator circuit being used to regulate the alternating electromotive force to provide a stable voltage source to the load; a temperature acquisition circuit connected to the second voltage regulator circuit, the temperature acquisition circuit being connected to a temperature sampling sensor to acquire temperature signals; and a second microcontroller module connected to the temperature acquisition circuit, the second microcontroller module being connected to the second voltage regulator circuit and the equivalent impedance changing switch circuit.

[0089] During power supply, the secondary coil induces an alternating electromotive force, which is then rectified and filtered by the rectifier and filter circuit, and then regulated by the voltage regulator circuit to provide a stable power supply to the second microcontroller module, temperature acquisition circuit, and temperature sampling sensor. After the temperature sampling sensor acquires the temperature signal, the temperature acquisition circuit obtains the corresponding temperature signal and sends it to the second microcontroller module for processing. The signal is then sent to the equivalent impedance changing switch circuit. Upon receiving the signal, the equivalent impedance changing switch circuit changes the connected resistance value to generate an impedance change signal, which is then sent to the primary coil by the secondary coil through electromagnetic induction, thereby realizing the acquisition and transmission of the temperature signal.

[0090] Specifically, the rectifier filter circuit and the second voltage regulator circuit can use existing circuit structures, which will not be elaborated here. Figure 5 and Figure 6 As shown, the temperature acquisition circuit includes a temperature sampling chip and a sampling analog circuit connected to the temperature sampling chip. The sampling analog circuit includes several sampling branches corresponding to each temperature sampling sensor. Each sampling branch is connected to the temperature sampling chip through a low-pass filter. In this embodiment, the temperature sampling sensor uses a PT100 platinum resistance thermometer and is provided in four groups. The corresponding sampling analog circuit is provided with at least four sampling branches corresponding to each temperature sampling sensor. The temperature sampling chip uses a time-division multiplexing method to perform digital-to-analog conversion (ADC) on the four voltage signals. It switches between the four signals at a set frequency, samples the voltage signals of each channel in sequence, and amplifies and converts them into data signals to be transmitted to the second microcontroller module.

[0091] A constant current source is provided by a temperature sampling chip. After the temperature sampling sensor collects the temperature signal, it is converted into a voltage signal. After passing through a low-pass filter, high-frequency interference can be effectively suppressed. Each sampling branch can transmit the signal collected by each temperature sampling sensor to the temperature sampling chip, and then the temperature sampling chip performs the corresponding processing to complete the temperature sampling process.

[0092] like Figure 7 As shown, the second microcontroller module includes the MKE02Z64VL C2 chip and its peripheral circuitry, such as... Figure 8As shown, the equivalent impedance change switching circuit includes: a field-effect transistor U2 connected to the second microcontroller module, and a current-limiting resistor connected to the field-effect transistor U2. The field-effect transistor U2 turns on in response to the temperature signal to connect to the current-limiting resistor, generating an impedance change signal. The No. 1 interface of the field-effect transistor is connected to the DRV interface of the PTB1 port of the MKE02Z64VL C2 chip. By turning the field-effect transistor U2 on and off, the current-limiting circuit is connected to or disconnected from the circuit, realizing the change of the equivalent resistance value in the circuit, thereby causing the current amplitude to change, which can form an impedance change signal. For example, when the field-effect transistor U2 is on, the current flows through this branch, which is equivalent to connecting a current-limiting resistor in parallel with the equivalent impedance on the rotor side. The equivalent impedance of the new circuit will be significantly reduced, and the circuit flowing through the secondary coil will be correspondingly increased.

[0093] like Figure 4 As shown, the first processing unit includes: a first voltage regulator circuit connected to the signal conditioner; a first microcontroller module connected to the first voltage regulator circuit; and an H-bridge driver connected to the first microcontroller module. The H-bridge driver is connected to the primary coil and the signal conditioner and is used to invert the DC power supply into a variable frequency AC circuit to supply the primary coil so that the split transformer outputs a predetermined voltage value. The voltage source passing through the signal conditioner is regulated by the first voltage regulator circuit, thereby providing a stable power supply to the first microcontroller module. The H-bridge driver then inverts the DC power supply into a variable frequency AC circuit to supply the primary coil, so that the voltage output on the secondary coil side is only related to the turns ratio of the primary coil and the secondary coil. Therefore, after selecting an appropriate turns ratio, a predetermined voltage value can be output.

[0094] Specifically, such as Figure 9 As shown, the first voltage regulator circuit includes two input terminals, P1 and P2. P1 and P2 are long wire interfaces. The signal conditioner supplies power to the first processing unit through P1 and P2. A fast recovery diode D3 is connected to the P1 input terminal to prevent reverse power connection, thus avoiding damage to subsequent circuits caused by reversed wire polarity. Zener diode D7 limits the voltage amplitude to 24V to prevent damage from overvoltage or pulse voltage. C6 is a tantalum capacitor for filtering. R18 acts as a voltage divider. The larger the voltage difference between the input and output voltages of the KA78M05RTM, the greater its power and the more severe the heat generation. Adding a voltage divider resistor significantly improves its heat generation.

[0095] like Figure 10 As shown, Figure 10 The circuit schematic of the first microcontroller module is shown, as follows: Figure 11 As shown, Figure 11 The circuit schematic of the H-bridge driver is shown, such as... Figure 12 As shown, Figure 12The equivalent circuit diagram of the H-bridge driver is shown. The H-bridge driver includes an H-bridge driver chip and its peripheral circuits, which can be equivalent to four sets of transistors connected in sequence. The H-bridge driver chip uses a MAX13256 microcontroller, which has a built-in clock, but an external clock is used in this embodiment. The CLK pin is connected to a 2MHz clock supplied by the first microcontroller module to drive the H-bridge driver. The internal flip-flop divides the external clock by two to ensure that the duty cycle of the generated switching signal is 50%. Therefore, the frequency of the AC power supply output by the driver is half of the frequency of the external clock supplied by the first microcontroller module, which is 1MHz.

[0096] like Figure 4 and Figure 13 As shown, the signal conditioner includes: an analog power supply circuit connected to an external power supply; a digital power supply circuit connected to an external power supply; a current sampling circuit connected to a first processing unit for acquiring current signals fed back by a second processing unit to extract temperature signals; a filter amplifier circuit connected to the current sampling circuit; a main control microcontroller connected to the filter amplifier circuit, the main control microcontroller being connected to the digital power supply circuit; a digital isolation circuit connected to the main control microcontroller, the digital isolation circuit being connected to both the analog power supply circuit and the digital power supply circuit; and a DA converter connected to the digital isolation circuit, the DA converter being connected to the analog power supply circuit.

[0097] Different power supply requirements can be met by using analog power supply circuits and digital power supply circuits. The current signal output by the first processing unit is received by the current sampling circuit. The current signal is amplified by the filtering and amplification circuit. After the main control unit performs calculations, the corresponding temperature signal data is obtained. The corresponding current value is then output and written into the DA converter to complete the transmission of the temperature signal.

[0098] Specifically, such as Figure 14 As shown, Figure 14 The circuit schematic of a digital circuit power supply is shown, such as... Figure 15 As shown, Figure 15 The circuit diagram of the analog circuit power supply is shown. The digital circuit power supply and the analog circuit power supply are isolated by a digital isolation circuit, which effectively isolates interference sources and reduces noise. The external power supply is a 24V DC power supply, which is also the only external power supply for the entire temperature transmitter. The digital circuit power supply provides 5V DC power to the first microcontroller module, bandpass filter chip, etc., while the analog circuit power supply provides 12V DC power to the digital-to-analog converter circuit and also needs to supply 5V DC power to the digital isolation circuit.

[0099] like Figure 16 As shown, Figure 16The circuit diagram of the current sampling circuit is shown. The current sampling circuit includes: a connection interface P10 connected to an external power supply; a sampling diode D11 with its anode connected to the connection interface P10 and its cathode grounded; the anode of the sampling diode D11 is connected to the filter amplifier circuit through a sampling resistor R6; since the signal conditioner is usually far from the motor, it can be connected to the first processing unit through the connection interface using a long wire; in order to extract the temperature signal from the current signal, the voltage signal across the acquisition device is generally used in series, that is, the current signal is converted into a voltage signal. Since it is only necessary to detect the change in current amplitude when extracting the temperature signal, and not the magnitude of the change, the sampling diode is used instead of the existing sampling resistor. The voltage value across its terminals can change with the current flowing through it, realizing the current sampling process. D11 is an ultra-fast recovery diode with a recovery time of 75 ns and a forward voltage of less than 1.3V. The voltage across its terminals changes with the current flowing through it, but the change amplitude is much smaller than that of the sampling resistor.

[0100] like Figure 17 As shown, Figure 17 The circuit diagram of the filter amplifier circuit is shown. The filter amplifier circuit includes a filter chip connected to the current sampling circuit and an amplifier circuit module connected to the filter chip. The amplifier circuit module includes several connected amplifiers. Since the communication signal in the current is extracted by sampling the voltage across the sampling diode D11, it is necessary to filter the communication signal. Since the voltage across the sampling diode D11 changes very little with the current, the signal also needs to be amplified. The filter chip can extract the signal obtained by the current sampling circuit, and then the amplifier circuit module amplifies it to make the signal easier to identify.

[0101] like Figure 18 As shown, Figure 18 The circuit diagram of the digital isolation circuit is shown. The ADuM1200 isolator provides two independent isolation channels. The two power supplies can range from 2.7V to 5.5V. In this embodiment, the signal conditioner uses three isolation chips. V5 and GND are the power supply and digital ground for the digital circuit; ISOV5 and ISOGND are the power supply and analog ground for the analog circuit; SPI1_MOSI, SPI1_SCK, and SPI1_MISO are the SPI communication interfaces on the microcontroller side; and ADMISO, ADSCK, and ADMISO are the communication interfaces on the digital-to-analog converter side.

[0102] like Figure 19 As shown, Figure 19The circuit diagram of the DA converter is shown. A DA converter is a digital-to-analog converter (DAC). In this embodiment, the AD5420 is selected. This DA converter is a single-channel, 16-bit high-precision current-source DAC. The output current range can be selected as 0-24mA, 2-20mA, or 4-20mA. It requires a wide analog power supply range, from 10.8V to 40V. In addition, a 5V digital power supply is needed, which can be an external power supply or its built-in 5V power supply. Since the temperature transmitter in this embodiment needs to support simultaneous temperature measurement at four points and generate four channels of temperature data, four single-channel AD5420 DACs are required. Their output current range can be set via a program; in this embodiment, it is set to 0-24mA.

[0103] Taking one AD5420 and its surrounding circuitry as an example, the SDO of this chip is connected to the SDIN pin of the next AD5420. ADIOUT1 outputs one current, and P1 and P2 are the external interfaces for four current sources. When the current chip output range is set to 0-24mA, the output current is as follows, where D is the decimal equivalent value of the code loaded into the DAC chip, and N is the DAC resolution bit depth.

[0104]

[0105] Example 3

[0106] This embodiment provides a temperature acquisition method based on the high-speed rotary temperature transmitter described in Embodiment 1 or Embodiment 2, including:

[0107] S100, The first processing unit receives a power signal input from a signal conditioner to drive the primary coil to generate an alternating magnetic field so that the secondary coil is induced to generate an alternating electromotive force to supply power to the load.

[0108] S200, the second processing unit generates an impedance change signal reflecting the temperature signal data based on the temperature signal obtained by the temperature sampling sensor, so that the secondary coil sends the signal to the first processing unit through the primary coil via electromagnetic induction, and the impedance change signal is extracted by the signal conditioner to be conditioned into a current signal reflecting the temperature signal data.

[0109] Because the rotor-side circuit is powered by induced electromotive force, and the temperature signal is transmitted by electromagnetic induction by changing the current amplitude through impedance transformation to generate an impedance change signal, the two do not interfere with each other, resulting in higher measurement accuracy and better measurement effect. Moreover, the overall circuit structure is simpler, and no additional receiving and transmitting devices are required, resulting in lower cost.

[0110] Example 4

[0111] This embodiment provides a rotor temperature monitoring system, which is mainly used for real-time acquisition and monitoring of the rotor temperature of a high-speed permanent magnet motor. It includes: a high-speed rotary temperature transmitter as described in Embodiment 1 or Embodiment 2; and a temperature control cabinet connected to the output of a signal conditioner. The temperature control cabinet adjusts the motor's operating state based on the temperature signal data acquired by the high-speed rotary temperature transmitter. The temperature control cabinet can be an existing integrated control cabinet. In some embodiments, the temperature signal can also be uploaded to a cloud server and connected to a display device such as a screen for real-time display.

[0112] After the temperature signal is collected by the high-speed rotating temperature transmitter, it is transmitted to the temperature control cabinet, which monitors the temperature in real time and can perform functions such as alarm and motor operation adjustment based on the temperature signal. This can prevent the permanent magnet from being demagnetized in time when the temperature is too high and reduce motor damage.

[0113] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A high-speed rotary temperature transmitter, characterized in that, include: A split transformer, comprising a primary winding and a secondary winding coupled to each other, wherein the primary winding is disposed on the stator side of the motor and the secondary winding is disposed on the rotor side of the motor; A first processing unit connected to the primary coil, the first processing unit being connected to an external power supply via a signal conditioner, the first processing unit being used to drive the primary coil to generate an alternating magnetic field so that the secondary coil is induced to form an alternating electromotive force; A second processing unit is connected to the secondary coil. The second processing unit is connected to several temperature sampling sensors. The temperature sampling sensors are used to sample the temperature signal of the motor rotor in real time. The second processing unit responds to the temperature signal to generate an impedance change signal that reflects the temperature signal data. The secondary coil sends the signal to the first processing unit through the primary coil via electromagnetic induction. The signal conditioner extracts the impedance change signal and conditions it into a current signal that reflects the temperature signal data. The second processing unit includes: A rectifier and filter circuit connected to the secondary coil; An equivalent impedance changing switch circuit connected to the rectifier filter circuit is used to sense temperature signals to change the input resistance value and generate an impedance change signal. A second voltage regulator circuit is connected to the equivalent impedance change switching circuit. The second voltage regulator circuit is used to regulate the alternating electromotive force to provide a stable voltage source to the load. A temperature acquisition circuit connected to the second voltage regulator circuit, wherein the temperature acquisition circuit is connected to the temperature sampling sensor for acquiring temperature signals; A second microcontroller module is connected to the temperature acquisition circuit, and the second microcontroller module is connected to the second voltage regulator circuit and the equivalent impedance change switch circuit; The equivalent impedance change switching circuit includes: a field-effect transistor connected to the second microcontroller module, and a current-limiting resistor connected to the field-effect transistor. The field-effect transistor turns on in response to a temperature signal to connect to the current-limiting resistor and generate the impedance change signal. The signal conditioner includes: An analog power supply circuit that is connected to an external power source; A digital power supply circuit that is connected to an external power source; A current sampling circuit connected to the first processing unit is used to acquire the current signal fed back by the second processing unit to extract the temperature signal; A filter amplifier circuit connected to the current sampling circuit; A main control microcontroller is connected to the filter amplifier circuit, and the main control microcontroller is connected to the digital power supply circuit; A digital isolation circuit connected to the main control microcontroller, the digital isolation circuit being connected to both the analog power supply circuit and the digital power supply circuit; and, A DA converter connected to the digital isolation circuit, the DA converter being connected to the analog power supply circuit; The current sampling circuit includes: Connection interface for connecting to an external power source; A sampling diode with its anode connected to the connection interface and its cathode grounded is connected to the filter amplifier circuit via a sampling resistor.

2. The high-speed rotary temperature transmitter according to claim 1, characterized in that, The temperature acquisition circuit includes a temperature sampling chip and a sampling analog circuit connected to the temperature sampling chip. The sampling analog circuit includes several sampling branches corresponding to each of the temperature sampling sensors, and each of the sampling branches is connected to the temperature sampling chip through a low-pass filter.

3. The high-speed rotary temperature transmitter according to claim 1, characterized in that, The first processing unit includes: A first voltage regulator circuit connected to the signal conditioner; A first microcontroller module connected to the first voltage regulator circuit; and, An H-bridge driver connected to the first microcontroller module, the H-bridge driver being connected to the primary coil and the signal conditioner, is used to invert DC power into a variable frequency AC circuit to supply the primary coil so that the discrete transformer outputs a predetermined voltage value.

4. The high-speed rotary temperature transmitter according to claim 1, characterized in that, The filtering and amplification circuit includes: a filter chip connected to the current sampling circuit, and an amplification circuit module connected to the filter chip, wherein the amplification circuit module includes several connected amplifiers.

5. A temperature acquisition method, characterized in that, The temperature acquisition method is based on the high-speed rotary temperature transmitter according to any one of claims 1-4, and includes: The first processing unit receives a power signal input from a signal conditioner to drive the primary coil to generate an alternating magnetic field, thereby inducing an alternating electromotive force in the secondary coil to supply power to the load. The second processing unit generates an impedance change signal that reflects the temperature signal data based on the temperature signal obtained by the temperature sampling sensor, so that the secondary coil sends the signal to the first processing unit through the primary coil via electromagnetic induction, and the signal conditioner extracts the impedance change signal to condition it into a current signal that reflects the temperature signal data.

6. A rotor temperature monitoring system, characterized in that, include: The high-speed rotary temperature transmitter as claimed in any one of claims 1-4; and, A temperature control cabinet is connected to the output terminal of the signal conditioner. The temperature control cabinet is used to adjust the working state of the motor based on the temperature signal data obtained by the high-speed rotating temperature transmitter.

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