Power supply apparatus and temperature measurement method therefor

Abstract

A power supply apparatus (100), comprising a bus bar (BUS1), a circuit measurer (120), a temperature sensor (130), and an operation circuit (140). The bus bar (BUS1) is coupled to an inverter (110) and a motor (MOT1). The temperature sensor (130) is configured to measure an initial temperature in an initial state. The circuit measurer (120) is configured to measure a voltage (V1), a current (I1) and an alternating current frequency (F1) on the bus bar (BUS1). The operation circuit (140) is coupled to the circuit measurer (120) and the temperature sensor (130). The operation circuit (140) is configured to: solve a resistance value signal (R1) on the basis of the alternating current frequency (F1), solve a first transient power of the bus bar (BUS1) on the basis of the current (I1) and the resistance value signal (R1) on the bus bar (BUS1), solve a first temperature rise value of the bus bar (BUS1) on the basis of the first transient power, and add the initial temperature to the first temperature rise value so as to obtain a first transient ideal temperature of the bus bar (BUS1). The present invention further relates to a temperature measurement method (400) for the bus bar (BUS1).

Description

Power supply device and temperature measurement method thereof Technical Field

[0001] The present invention relates to a power supply device and a temperature measurement method thereof, and more particularly to a power supply device and a method thereof for estimating transient temperature. Background Art

[0002] Thermal management systems in the prior art typically rely on basic thermal models and require manual calibration. This approach can be inefficient and potentially cause failures under varying operating conditions. Temperature sensors can also be used to measure the operating temperature of circuit devices. However, these sensors primarily measure the steady-state temperature of circuit devices, such as the temperature change every 10 seconds during continuous operation. Such steady-state temperature measurements only represent the overall operating temperature of the circuit device and cannot reflect the transient temperature of the circuit device's internal wiring at a specific moment (e.g., measuring the temperature of a circuit bus during operation).

[0003] However, existing temperature sensors are unable to measure or calculate the transient temperature of the internal bus of the circuit in real time, which makes temperature monitoring difficult. Summary of the Invention

[0004] This disclosure provides a power supply device. The power supply device includes a bus, a current measuring device, a temperature sensor, and an operational circuit. The bus is coupled to an inverter and a motor. The temperature sensor is configured to measure an initial temperature in an initial state. The current measuring device is configured to measure the voltage, current, and AC frequency on the bus. The operational circuit is coupled to the current measuring device and the temperature sensor. The operational circuit is configured to: determine a resistance signal based on the AC frequency; determine a first transient power of the bus based on the current and resistance signal on the bus; determine a first temperature rise of the bus based on the first transient power; and determine a first transient ideal temperature of the bus by adding the initial temperature and the first temperature rise.

[0005] This disclosure provides a method for measuring the temperature of a busbar of a power supply device. The power supply device includes a busbar, a circuit measuring device, a temperature sensor, and an arithmetic circuit. The busbar is coupled to an inverter and a motor. The temperature measurement method includes: measuring an initial temperature in an initial state using the temperature sensor; measuring the current and AC frequency on the busbar using the circuit measuring device; obtaining a resistance signal based on the AC frequency using the arithmetic circuit; obtaining a first transient power of the busbar based on the current and resistance signals on the busbar; obtaining a first temperature rise value of the busbar based on the first transient power; and obtaining a first transient ideal temperature of the busbar by adding the initial temperature and the first temperature rise value.

[0006] In summary, the power supply device of the present disclosure can measure the bus voltage, current, and AC frequency, and thus calculate the transient temperature on the bus in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG1 is a schematic diagram of a power supply device according to an embodiment of the present disclosure.

[0008] FIG. 2A is a partial schematic diagram of the operation circuit according to the embodiment of FIG. 1 .

[0009] FIG. 2B is a graph showing a frequency-resistance curve according to the embodiment of FIG. 2A .

[0010] FIG. 3 is a graph related to the embodiment according to FIG. 2A .

[0011] FIG4 is a flow chart of a temperature measurement method according to an embodiment of the present disclosure.

[0012] Explanation of reference numerals: 100: power supply device 110: inverter SW1, SW2, SW3, SW4, SW5, SW6: switching switch 120: circuit measuring device 130: temperature sensor 140: calculation circuit SC1, SC2: cable GND: ground terminal C1, C2, C3, C4, C5, C6: capacitor CID1, CID2: coupled inductor MOT1: motor BUS1: bus V1: voltage I1: current F1: AC frequency T[0]: initial temperature T[1]~T[n]: operating environment temperature ADC1, ADC2: analog-to-digital converter D SP1: Digital signal processor AADC1: Digital gain controller FRC2: Frequency-resistance converter PD1: Power estimation unit TD1: Temperature estimation unit CMP1: Comparison circuit SIN_ER: Control signal DT[0]: Digital initial temperature DT[1]~DT[n]: Digital ambient temperature D1: Digital current value R1: Resistance value signal TP[1]~TP[n]: Transient power TTI[1]~TTI[n]: Transient ideal temperature 400: Temperature measurement method S410, S420, S430, S440, S450, S460: Steps DETAILED DESCRIPTION

[0013] The following will illustrate the embodiments of the present disclosure with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar elements or method flows.

[0014] Please refer to FIG1 , which is a schematic diagram of a power supply device 100 according to one embodiment of the present disclosure. In the embodiment of FIG1 , power supply device 100 includes at least cables SC1 and SC2 , coupled inductors CID1 and CID2 , capacitors C1 to C6 , a motor MOT1 , an inverter 110 , a current meter 120 , a temperature sensor 130 , a bus BUS1 , and a computing circuit 140 .

[0015] In one embodiment, the power supply device 100 can be used in the power supply system of an electric vehicle (as shown in the embodiment of FIG. 1 , to power the drive motor MOT1). However, the present disclosure is not limited thereto, and the power supply device 100 can also be used in a renewable energy system (e.g., solar or wind energy) or a power supply device based on direct current (e.g., a battery) feeding power to an alternating current (AC) grid. In these examples, the load will be replaced by an AC grid (not shown) or other similar AC power loads instead of the motor MOT1 shown in FIG. 1 . The inverter 110 is used to convert a DC power input (e.g., a battery, a solar panel, a wind turbine) into a specific AC power output.

[0016] In one embodiment, the inverter 110 of the power supply device 100 includes switches SW1 - SW6 . The main function of the inverter 110 is to convert DC input into AC output of a specific specification.

[0017] In one embodiment, the switching switches SW1 to SW6 may be switching elements such as insulated gate bipolar transistors (IGBTs) or metal oxide semiconductor field effect transistors (MOSFETs). The switching switches SW1 to SW6 respectively switch their switching states according to the gate signal to generate three-phase alternating current. The switching switches SW1 to SW6 are controlled by precise switching actions to generate waveforms of the required frequency and voltage. Three groups of switching switches SW1 to SW6 form a three-phase system, and each group controls the voltage of one phase, thereby forming a balanced three-phase alternating current. By adjusting the switching speed of the switching switches SW1 to SW6, the output frequency can be adjusted to control the operating frequency of the motor MOT1 (i.e., the AC frequency F1 in Figure 1). Precise switching control can maximize the control of the power consumption of the circuit and reduce the energy loss of the power supply device 100 as a whole, thereby improving the system efficiency.

[0018] In one embodiment, cables SC1 and SC2 can receive an input voltage and be coupled to ground GND. Cable SC1 can also be coupled to a first terminal of capacitor C1. The first terminal of capacitor C1 is coupled to ground GND and a first terminal of capacitor C2. Cable SC2 can also be coupled to a second terminal of capacitor C2. In one embodiment, cables SC1 and SC2 can each be a shielded cable coated with an insulating material.

[0019] A first input terminal of coupled inductor CID1 is coupled to the first terminal of capacitor C1. A first output terminal of coupled inductor CID1 is coupled to the first terminal of capacitor C3 and the first terminal of capacitor C4. A second input terminal of coupled inductor CID1 is coupled to the second terminal of capacitor C2. A second output terminal of coupled inductor CID1 is coupled to the second terminal of capacitor C3 and ground GND. A second terminal of capacitor C4 is coupled to ground GND.

[0020] As shown in FIG1 , capacitors C5 and C6 may also be provided within inverter 110. A first end of switch SW1 is coupled to capacitors C4 and C5, a first end of switch SW2, capacitor C6, and a first end of switch SW3. A second end of switch SW1 is coupled to a first end of switch SW4. A second end of switch SW2 is coupled to a first end of switch SW5. A second end of switch SW3 is coupled to a first end of switch SW6. The second ends of switches SW4, SW5, and SW6 are all coupled to ground GND.

[0021] The inverter 110 is coupled to the input terminal of the coupled inductor CID2 . The three-phase input terminal of the motor MOT1 can be connected to the output terminal of the coupled inductor CID2 via the busbar BUS1 .

[0022] The measuring terminal of the circuit meter 120 can be located on one of the cables of bus BUS1, for example, connected to one of the three-phase input terminals of motor MOT1, to measure the voltage V1 and current I1 flowing through bus BUS1. The circuit meter 120 may include a frequency measurement function. Since the input terminal of motor MOT1 receives AC power, the circuit meter 120 can measure the AC frequency F1 simultaneously with the voltage V1 and current I1. In one embodiment, the measuring terminals of the circuit meter 120 can also be located on multiple cables of bus BUS1. In this embodiment, the current I1 can represent the multi-phase current on multiple cables.

[0023] The measuring end of the temperature sensor 130 can be set on the circuit board of the power supply device 100, that is, the circuit board on the surface of the bus BUS1. For example, the measuring end can be set at any position near the bus BUS1, as shown in Figure 1. The present invention does not limit the specific position of the measuring end of the temperature sensor 130 in the power supply device 100. The temperature sensor 130 can be used to measure the initial temperature T[0] of the setting position at the moment of starting operation (also called "initial state") and the operating environment temperature T[1]~T[n] after the bus BUS1 has been running for a period of time. Here, "n" can be any positive integer greater than 1, representing the number of times the temperature sensor 130 measures the bus BUS1 during the operation of the bus BUS1, and also represents the number of operating environment temperatures measured by the temperature sensor 130 near the bus BUS1.

[0024] The operation circuit 140 is coupled to the circuit measurer 120 and the temperature sensor 130. The operation circuit 140 can receive the voltage V1, the current I1, and the AC frequency F1 through the circuit measurer 120. In addition, the operation circuit 140 can receive the initial temperature T[0] and the operating environment temperatures T[1]-T[n] through the temperature sensor 130.

[0025] In one embodiment, the computing circuit 140 of the present disclosure monitors / estimates the transient temperature of bus BUS1 to control and provide over-temperature protection for bus BUS1. This over-temperature protection is achieved by adjusting voltage V1, current I1, and AC frequency F1 via switches SW1-SW6. The following embodiments will detail how computing circuit 140 monitors / estimates the transient temperature and provides subsequent over-temperature protection.

[0026] In the initial state, the computing circuit 140 may receive the initial temperature T[0] via the temperature sensor 130 and calculate the transient power TP[1] based on the initial temperature T[0], the current I1 measured by the circuit measurement device 120 in the initial state, and the AC frequency F1. After calculating the transient power TP[1], the computing circuit 140 calculates a first temperature rise value corresponding to the transient power TP[1]. The computing circuit 140 then adds the first temperature rise value and the initial temperature T[0] to calculate the transient ideal temperature TTI[1] of the bus BUS1.

[0027] After the initial state, the power supply device 100 can continue to operate, and the temperature inside the bus BUS1 may increase over time, thereby causing the thermal resistance of the bus BUS1 to change as the temperature increases. When the power supply device 100 is operating, the operation circuit 140 can first receive the initial temperature T[0] through the temperature sensor 130, and calculate the transient power TP[2] of the bus BUS1 based on the transient ideal temperature TTI[1], the current I1 measured in real time by the circuit measurer 120, and the AC frequency F1. After calculating the transient power TP[2], the operation circuit 140 can calculate the second temperature rise value of the bus BUS1 based on the transient power TP[2]. Then, the operation circuit 140 can add the second temperature rise value and the initial temperature T[0] to calculate the transient ideal temperature TTI[2] of the bus BUS1.

[0028] The calculation circuit 140 can continuously calculate the transient ideal temperature TTI[3] based on the current I1, the AC frequency F1, and the transient ideal temperature TTI[2]. The calculation circuit 140 can iterate the above operation continuously to calculate the temperature value of the bus BUS1 at a certain time point based on the current I1 and the AC frequency F1 of the bus BUS1 at that time point.

[0029] In summary, the power supply device 100 can calculate the transient temperature of the bus BUS1 in real time by only measuring the current I1 and the AC frequency F1 of the bus BUS1 .

[0030] In addition to the above functions, in the embodiment of FIG. 1 , the computing circuit 140 of the power supply device 100 can further compare the transient ideal temperature of the bus BUS1 at a certain time point after the power supply device 100 operates from an initial state to the operating environment temperature measured by the temperature sensor, thereby determining whether an abnormality has occurred in the bus BUS1.

[0031] When the computing circuit 140 determines that bus BUS1 has an abnormality (e.g., transient overtemperature or insufficient service life), the computing circuit 140 quickly shuts off the power supply to motor MOT1 by deactivating switches SW1-SW6, preventing current from flowing through bus BUS1 and protecting the system from damage caused by overload or faults. The coordinated operation of switches SW1-SW6 ensures stable and efficient operation of the power supply device 100.

[0032] Furthermore, the computational circuit 140 may be configured with a conduction function, which is determined based on the location of the temperature sensor 130's measuring end within the bus BUS1 and the thermal conductivity of the conductive medium (e.g., copper wire, a heat pipe, or a heat-conducting metal sheet) at the temperature sensor 130's measuring end. The computational circuit 140 may convert the ambient operating temperature into the bus operating temperature of the bus BUS1 based on the conduction function. In other words, the computational circuit 140 may estimate the bus operating temperature of the bus BUS1 based on the conduction function and the ambient operating temperature. The computational circuit 140 may compare the bus operating temperature of the bus BUS1 with the transient ideal temperature to determine whether an abnormality has occurred on the bus BUS1 at that point in time.

[0033] When the difference between the bus operating temperature and the transient ideal temperature exceeds a first threshold, it indicates that bus BUS1 has aged, resulting in an increase in its thermal resistance. In this case, computation circuit 140 can send control signals to the gates of switches SW1-SW6 to control the operation of switches SW1-SW6. In this manner, computation circuit 140 can reduce the current I1 flowing through bus BUS1 or its frequency, thereby placing power supply device 100 in load reduction mode and extending its service life.

[0034] When the difference between the bus operating temperature and the transient ideal temperature exceeds the second threshold, it indicates that bus BUS1 has aged excessively. If no action is taken, the entire power supply device 100 may malfunction. In this embodiment, the second threshold is higher than the first threshold. In this case, the computing circuit 140 can send a control signal to the gates of the switching switches SW1-SW6, causing the switching switches SW1-SW6 in the overall inverter 110 to stop supplying current to the motor MOT1. In some embodiments, when the computing circuit 140 detects this phenomenon, it can generate and transmit a warning message (such as explanatory text, graphics, or an alarm sound) to a display, speaker, or other output interface. This notifies the user or maintenance personnel of the current aging of bus BUS1, allowing them to perform targeted repairs or maintenance.

[0035] In the above embodiment, a widening gap between the bus operating temperature and the transient ideal temperature may indicate that the cables, including bus BUS1, are worn out or have a limited service life. For example, a Rainflow algorithm can be executed to estimate the service life of bus BUS1 based on the deviation in the operating temperature of bus BUS1. If the service life of bus BUS1 is determined to be insufficient, maintenance personnel can be prompted to replace it.

[0036] Please refer to Figures 2A and 2B simultaneously. Figure 2A is a partial schematic diagram of the operation circuit 140 according to the embodiment of Figure 1, and Figure 2B is a frequency-resistance curve according to the embodiment of Figure 2A. The operation circuit 140 may include an analog-to-digital converter ADC1, an analog-to-digital converter ADC2, a digital signal processor DSP1, a digital gain amplifier AADC1, a frequency-resistance converter FRC2, a power estimation unit PD1, a temperature estimation unit TD1, and a comparison circuit CMP1.

[0037] In the embodiment of FIG2A , the input end of the analog-to-digital converter ADC1 can sequentially receive the initial temperature T[0] and the operating environment temperature T[1]~T[n] through the temperature sensor 130, and the output end of the analog-to-digital converter ADC1 can be coupled to the digital signal processor DSP1. The initial temperature T[0] and the operating environment temperature T[1]~T[n] are both analog signals. The initial temperature T[0] and the operating environment temperature T[1]~T[n] can be converted into a digital initial temperature T[0] and a digital environment temperature T[1]~T[n] through the analog-to-digital converter ADC1 and the digital signal processor DSP1, and the digital initial temperature DT[0] and the digital environment temperature DT[1]~DT[n] are both digital signals.

[0038] The input of analog-to-digital converter ADC2 can receive current I1 via circuit measurer 120. The output of analog-to-digital converter ADC2 can be coupled to digital gain amplifier AADC1. Current I1 is an analog signal. Analog-to-digital converter ADC2 and digital gain amplifier AADC1 can convert current I1 into a digital current value D1, which is a digital signal.

[0039] The input of frequency-to-resistance converter FRC2 can receive AC frequency F1 via circuit measurement device 120. Frequency-to-resistance converter FRC2 can determine resistance based on frequency, as shown in the frequency-to-resistance graph of FIG2B . Frequency-to-resistance converter FRC2 can output a resistance signal R1 based on AC frequency F1.

[0040] The power estimation unit PD1 can receive the digital initial temperature DT[0], the digital current value D1, and the resistance value signal R1. The power estimation unit PD1 can calculate the transient power TP[1] based on the above values. After calculating the transient power TP[1], the power estimation unit PD1 can continue to calculate the transient power TP[1] based on the transient power TP[1], the digital current value D1, and the resistance value signal R1, and so on. The power estimation unit PD1 can sequentially calculate the transient powers TP[1] to TP[n].

[0041] The temperature estimation unit TD1 is coupled to the power estimation unit PD1 and the digital signal processor DSP1 , and can receive the transient powers TP[1]-TP[n] from the power estimation unit PD1 and the digital initial temperature DT[0] from the digital signal processor DSP1 .

[0042] Based on the transient powers TP[1]-TP[n], the temperature estimation unit TD1 can correspondingly calculate n temperature rise values ​​of the busbar. The temperature estimation unit TD1 can sequentially add the n temperature rise values ​​and the digital initial temperature DT[0] to calculate the transient ideal temperatures TTI[1]-TTI[n].

[0043] The comparison circuit CMP1 can sequentially receive digital ambient temperatures DT[1]-DT[n] from the digital signal processor DSP1 and transient ideal temperatures TTI[1]-TTI[n] from the temperature estimation unit TD1. The comparison circuit CMP1 can convert the digital ambient temperatures DT[1]-DT[n] into a bus operating temperature on the bus BUS1 according to the transfer function mentioned above. The comparison circuit CMP1 can sequentially compare the bus operating temperatures corresponding to the digital ambient temperatures DT[1]-DT[n] with the transient ideal temperatures TTI[1]-TTI[n] and output a control signal SIN_ER based on the comparison result.

[0044] For example, when the comparison circuit CMP1 receives the digital ambient temperature DT[1] and the transient ideal temperature TTI[1], the digital ambient temperature DT[1] can be converted into the corresponding bus operating temperature. When the difference between the bus operating temperature and the transient ideal temperature TTI[1] is greater than the first threshold value, the comparison circuit CMP1 can send a control signal SIN_ER to the switching switches SW1~SW6, thereby controlling the operation of the switching switches SW1~SW6. In the above manner, the operation circuit 140 can reduce the current I1 input to the motor MOT1. When the difference between the bus operating temperature and the transient ideal temperature TTI[1] is greater than the second threshold value, the comparison circuit CMP1 can send a control signal SIN_ER to the switching switches SW1~SW6, causing the switching switches SW1~SW6 of the inverter 110 to stop supplying current to the motor MOT1.

[0045] Please refer to Figure 3, which is a graph related to the embodiment of Figure 2A. The graph of Figure 3 includes a measurement curve that represents the corresponding relationship between the equivalent thermal resistance of bus BUS1 (including the circuit board on the surface) and the equivalent thermal capacitance of bus BUS1 (including the circuit board on the surface). This measurement curve is obtained by integrating the measured values ​​of the thermal resistance of bus BUS1 over time with the measured values ​​of the thermal capacitance of bus BUS1 over time.

[0046] In FIG3 , the measurement curve is measurement data pre-stored in a storage device built into the computing circuit 140 , and the measurement curve is obtained by measuring the thermal resistance and thermal capacitance of the object to be tested (i.e., the bus BUS1 and the circuit board disposed on the surface of the bus) and the circuit operating environment used by the power supply device 100 . Based on FIG3 , the temperature of the bus BUS1 can be inferred by measuring the temperature of the circuit board on the surface of the bus. FIG3 is a curve generated by measuring temperature changes in a short period of time. Therefore, it is possible to measure the transient response (transient change) of the object to be tested as the temperature changes. Therefore, the bus temperature inferred according to the present invention is more accurate. In addition, since the measurement curve of the present invention is obtained through transient changes of a multi-layer structure (the bus BUS1 and the circuit board disposed on the surface of the bus), it is possible to determine whether the bus or only the circuit board temperature is too high by measuring the surface temperature of the circuit board.

[0047] In one embodiment, a user of the present invention can construct a usage environment equivalent to that of the power supply device 100 in a laboratory environment, and measure the AC frequency and resistance of the bus BUS1 one by one while controlling the ambient temperature and maintaining a constant on-current. The power loss of the bus BUS1 can then be inferred based on the on-current, resistance, and AC frequency. In some embodiments, the relationship between the power loss and the ambient temperature can be recorded as a comparison table.

[0048] Please refer to FIG4 . FIG4 is a flow chart of a temperature measurement method 400 according to an embodiment of the present disclosure. The temperature measurement method 400 is used to measure and estimate the transient ideal temperature of the bus BUS1 of the power supply device 100 .

[0049] In step S410 , the power supply device 100 may measure the initial temperature T[0] in the initial state through the temperature sensor 130 .

[0050] In step S420 , the power supply device 100 may measure the current I1 and the AC frequency F1 on the bus BUS1 through the current measurement device 120 .

[0051] In step S430 , the power supply device 100 may obtain the resistance signal R1 based on the AC frequency F1 through the calculation circuit 140 .

[0052] In step S440 , the power supply device 100 may calculate the transient power TP[1] of the bus BUS1 based on the current I1 and the resistance signal R1 on the bus BUS1 .

[0053] In step S450 , the power supply device 100 may calculate a first temperature rise value of the bus BUS1 based on the transient power TP[ 1 ].

[0054] In step S460 , the power supply device 100 may add the initial temperature T[ 0 ] and the first temperature rise value to calculate the transient ideal temperature TTI[ 1 ] on the bus BUS1 .

[0055] After step S460 , the power supply device 100 may receive the transient ideal temperature TTI[1] and continuously calculate the transient ideal temperatures TTI[2] to TTI[n] according to the temperature measurement method 400 .

[0056] In summary, the power supply device 100 of the present invention can calculate the transient temperature of bus BUS1 in real time by simply measuring the current I1 and AC frequency F1 on bus BUS1. Furthermore, in some cases, the power supply device 100 of the present invention can also determine whether the cables within the power supply device 100, including bus BUS1, have aged by comparing the transient ideal temperature with the ambient temperature during system operation.

[0057] The above are only preferred embodiments of the present disclosure. Various modifications and equivalents may be made to the present disclosure without departing from the scope or concept of the present disclosure. In summary, all modifications and equivalents made to the present disclosure within the scope of the claims are within the scope of the present disclosure.

Claims

1. A power supply device, comprising: a bus bar for coupling an inverter and a motor; A temperature sensor for measuring an initial temperature in an initial state: a circuit measuring device for measuring a voltage, a current, and an AC frequency on the bus; and an operating circuit coupled to the circuit measurer and the temperature sensor, for: Calculating a resistance value signal based on the AC frequency; Calculating a first transient power of the bus based on the current on the bus and the resistance signal; and calculating a first temperature rise value of the bus based on the first transient power; and The initial temperature and the first temperature rise value are added together to obtain a first transient ideal temperature of the bus.

2. The power supply device as claimed in claim 1 , wherein the computing circuit is further configured to: When the power supply device is in operation, a second transient power of the bus is obtained according to the first transient ideal temperature, the current, and the AC frequency; Calculating a second temperature rise value of the busbar based on the second transient power; and The initial temperature and the second temperature rise value are added together to obtain a second transient ideal temperature of the bus.

3. The power supply device as claimed in claim 1 , wherein the computing circuit is further configured to: When the power supply device is running, measuring an operating environment temperature through the temperature sensor; estimating a bus operating temperature of the bus according to the operating environment temperature and a conduction function between the bus and the temperature sensor; The busbar operating temperature is compared with the first transient ideal temperature to determine whether the busbar is abnormal.

4. The power supply device according to claim 3, wherein: When the difference between the bus operating temperature and the first transient ideal temperature is greater than a first threshold value, the operation circuit sends a control signal to reduce the current flowing through the bus. When the difference between the bus operating temperature and the first transient ideal temperature is greater than a second threshold value, the operation circuit sends the control signal to stop the bus operating, and the second threshold value is higher than the first threshold value.

5. The power supply device as claimed in claim 1 , wherein the calculation circuit calculates a motor loss power and a total power of the motor according to the initial temperature, the current on the bus, and the AC frequency, and calculates the first transient power of the bus according to the motor loss power and the total power.

6. A method for measuring the temperature of a busbar of a power supply device, the power supply device comprising the busbar, a current measuring device, a temperature sensor, and a computing circuit, wherein the busbar is coupled to an inverter and a motor, the temperature measurement method comprising: Measuring an initial temperature in an initial state by the temperature sensor; Measuring a current and an AC frequency on the busbar by the circuit measuring device; Calculating a resistance value signal based on the AC frequency through the operation circuit; Calculating a first transient power of the bus based on the current on the bus and the resistance signal; Calculating a first temperature rise value of the busbar based on the first transient power; as well as The initial temperature and the first temperature rise value are added together to obtain a first transient ideal temperature of the bus.

7. The temperature measurement method according to claim 6, further comprising: When the power supply device is running, a second transient power of the motor is calculated according to the first transient ideal temperature, the current, and the AC frequency; Calculating a second temperature rise value of the busbar based on the second transient power; and The initial temperature and the second temperature rise value are added together to obtain a second transient ideal temperature of the bus.

8. The temperature measurement method according to claim 6, further comprising: When the power supply device is running, measuring an operating environment temperature through the temperature sensor; estimating a bus operating temperature of the bus according to the operating environment temperature and a conduction function between the bus and the temperature sensor; The busbar operating temperature is compared with the first transient ideal temperature to determine whether the busbar is abnormal.

9. The temperature measurement method according to claim 8, further comprising: When the difference between the operating temperature of the bus and the first transient ideal temperature is greater than a first threshold value, a control signal is sent to reduce the current flowing through the bus. When the difference between the bus operating temperature and the first transient ideal temperature is greater than a second threshold value, the control signal is sent to stop the bus operating, and the second threshold value is higher than the first threshold value.

10. The temperature measurement method as claimed in claim 6, wherein the step of obtaining the first transient power of the bus comprises: A motor power loss and a total power of the motor are calculated according to the initial temperature, the current on the bus, and the AC frequency, and the first transient power of the bus is obtained according to the motor power loss and the total power.

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