Switching loss measurement method and measurement device

Abstract

A switching loss measuring method and a measuring device, wherein the switching loss measuring method is to perform a switching timing measuring procedure on an input voltage inputted from a main voltage acquisition channel and an input current from a main current acquisition channel to generate a measuring time data; to calculate a switching loss data from the main voltage acquisition channel and the main current acquisition channel; to acquire the input voltage corresponding to the measuring time data and the input current from an auxiliary voltage acquisition channel to calculate a conduction loss data; the input voltage acquired from the auxiliary voltage acquisition channel has a better voltage resolution, so that the calculation of the conduction loss data is more accurate, and a switching loss data calculated from the switching loss data and the conduction loss data is also more accurate.

Description

Technical Field

[0001] A method and apparatus for measuring switching losses, particularly a method and apparatus for measuring switching losses by means of an auxiliary voltage acquisition channel for acquiring an input voltage and an auxiliary current acquisition channel for acquiring an input current. Background Technology

[0002] In today's information-rich society, all kinds of electronic products need to be subject to quality control, and an important device for controlling the quality of electronic products is an oscilloscope that displays signals.

[0003] This oscilloscope measures, captures, and displays a signal input to it within its preset voltage and current ranges. More precisely, when a signal is input to the oscilloscope, regardless of whether voltage or current is being measured, the input is always a voltage signal. This is because when measuring a current signal, the Hall effect generated by a current probe converts the current signal change into a voltage signal before outputting it to the oscilloscope. Under normal circumstances, a stable signal does not fluctuate significantly in either its voltage or current range, allowing the oscilloscope to display and perform calculations correctly. However, when the signal is switched on and off by a switching element in the circuit, its voltage and current ranges change dramatically, making it difficult for the oscilloscope to accurately capture the voltage and current.

[0004] When a switching power supply attempts to calculate the energy loss during switching using a measuring instrument, the voltage and current ranges of the signal will exhibit significant dynamic changes due to the switching action. This dynamic change can range from hundreds of volts when the switch is off to hundreds of millivolts when it is on, resulting in a voltage range variation equivalent to a thousandfold. Typical high-speed waveform update oscilloscopes cannot accurately capture these voltage and current changes during switching with 8-bit signal resolution, and therefore cannot accurately calculate the energy loss during switching.

[0005] The energy loss during switching can be specifically divided into on-loss, off-loss, and conduction loss. On-loss corresponds to the energy loss when the signal is switched on by the switching element, off-loss corresponds to the energy loss when the signal is switched off by the switching element, and conduction loss corresponds to the energy loss when the switching element is switched on. Because these energy losses occur at specific times, they are discussed here in units of power. When using a single high voltage range to capture the on-loss and conduction loss of the signal, the smaller voltage range of the conduction state will lead to measurement inaccuracies due to insufficient resolution of the high voltage range, causing difficulties in measuring the conduction loss.

[0006] Please see Figures 12A to 13 As shown, an oscilloscope receives a signal. The oscilloscope captures the voltage of the signal to form a voltage signal 1', and the oscilloscope captures the current of the signal to form a current signal 2'. The oscilloscope further calculates the turn-on loss, the turn-off loss, and the conduction loss based on the voltage signal 1' and the current signal 2', and calculates a total power loss signal 3'. The total power loss signal 3' is obtained by multiplying the voltage signal 1' and the current signal 2'. Figures 12A to 12C In this process, the oscilloscope displays the voltage signal 1', the current signal 2', and the total power loss signal 3' on one screen. Figure 13 The results presented are the calculated values ​​of the turn-on loss, turn-off loss, and conduction loss. The oscilloscope's calculation of the conduction loss is inaccurate because the conduction loss should not be negative. A negative conduction loss would be equivalent to gaining energy, which is illogical. This demonstrates that the existing oscilloscope, when measuring the energy loss during switch switching, will be inaccurate in measuring the conduction loss due to variations in the signal voltage and current ranges. Therefore, Figure 12C The total power loss signal 3' displayed by the oscilloscope does not accurately represent the sum of the turn-on loss, the turn-off loss, and the conduction loss. Summary of the Invention

[0007] In view of the above problems, the present invention provides a method and device for measuring switch switching loss.

[0008] A method for measuring switch switching loss is performed by a switch switching loss measuring device. This method includes the following steps:

[0009] Step S1: Receive an input voltage from a main voltage acquisition channel and an auxiliary voltage acquisition channel of the loss measurement device by switching the switch, and receive an input current from a main current acquisition channel of the loss measurement device by switching the switch; wherein, the voltage level acquired by the auxiliary voltage acquisition channel is lower than the voltage level acquired by the main voltage acquisition channel.

[0010] Step S2: Perform a switching timing measurement program on the input voltage received from the main voltage acquisition channel and the input current received from the main current acquisition channel to generate measurement time data.

[0011] Step S3: Based on the measurement time data, extract the input voltage and input current corresponding to the measurement time data from the main voltage acquisition channel and the main current acquisition channel, and calculate a switching loss data. Also, extract the input voltage and input current corresponding to the measurement time data from the auxiliary voltage acquisition channel, and calculate a conduction loss data.

[0012] Step S4: Add the switching loss data and the conduction loss data together to obtain a switch switching loss data.

[0013] Preferably, as described above, the method for measuring switching loss includes an on-time data, a conduction time data, and an off-time data.

[0014] Furthermore, step S3 includes the following sub-steps:

[0015] Step S31: Based on the turn-on time data, extract the input voltage of the main voltage acquisition channel during one turn-on time as a turn-on voltage, and extract the input current of the main current acquisition channel during the turn-on time as a turn-on current; and based on the turn-off time data, extract the input voltage of the main voltage acquisition channel during one turn-off time as a turn-off voltage, and extract the input current of the main current acquisition channel during the turn-off time as a turn-off current;

[0016] Step S32: Multiply the turn-on voltage and the turn-on current to obtain a turn-on loss data, and multiply the turn-off voltage and the turn-off current to obtain a turn-off loss data;

[0017] Step S33: Add the opening loss data and the closing loss data together to obtain the switching loss data.

[0018] Preferably, in the aforementioned method for measuring switching loss, step S3 further includes the following sub-steps:

[0019] Step S34: Based on the conduction time data, extract the input voltage of the auxiliary voltage extraction channel during one conduction time as a conduction voltage, and extract the input current of the main current extraction channel during the conduction time as a conduction current.

[0020] Step S35: Multiply the conduction voltage and the conduction current to obtain the conduction loss data.

[0021] Preferably, the switching loss measurement method described above further includes, between step S1 and step S2:

[0022] Step S11: Receive another input current from an auxiliary current acquisition channel of the loss measurement device via the switch; wherein the current range acquired by the auxiliary current acquisition channel is less than the current range acquired by the main current acquisition channel;

[0023] Furthermore, step S3 includes the following sub-steps:

[0024] Step S34': Based on the conduction time data, extract the input voltage of the auxiliary voltage acquisition channel during one conduction time as a conduction voltage, and extract the input current of the auxiliary current acquisition channel during the conduction time as a conduction current;

[0025] Step S35': Multiply the conduction voltage and the conduction current to obtain the conduction loss data.

[0026] Preferably, as described in the aforementioned method for measuring switching loss, the method further includes the following steps after performing step S4:

[0027] Step S5: Calculate a saturation operating voltage value within the conduction time based on the conduction time data, the conduction voltage, and the conduction current;

[0028] Step S6: Calculate the on-resistance value during the on-time based on the on-time data, the on-voltage, and the on-current.

[0029] Preferably, as in the aforementioned method for measuring switching loss, the auxiliary voltage acquisition channel further includes multiple voltage channels.

[0030] Among them, the voltage level captured by the multiple voltage channels is lower than the voltage level captured by the main voltage acquisition channel, and the voltage levels captured by the multiple voltage channels decrease sequentially.

[0031] Specifically, according to the gear corresponding to the input voltage, when a switching element is turned on, the input voltage is sampled from the voltage channel of the corresponding gear as the turn-on voltage, and the turn-on voltage and the turn-on current are multiplied to obtain the turn-on loss data.

[0032] Preferably, in the aforementioned method for measuring switching loss, the auxiliary voltage acquisition channel further includes multiple voltage channels, and the auxiliary current acquisition channel further includes multiple current channels.

[0033] Among them, the voltage level captured by the multiple voltage channels is lower than the voltage level captured by the main voltage acquisition channel, and the voltage levels captured by the multiple voltage channels decrease sequentially.

[0034] Among them, the current level captured by the multiple current channels is smaller than the current level captured by the main current capturing channel, and the current levels captured by the multiple current channels decrease sequentially.

[0035] Specifically, according to the corresponding gears of the input voltage and the input current, when a switching element is turned on, the input voltage is sampled from the voltage channel of the corresponding gear as the on-state voltage, and the input current is sampled from the current channel of the corresponding gear as the on-state current. The on-state voltage and the on-state current are then multiplied to obtain the conduction loss data.

[0036] Another technical solution of the present invention provides a switching loss measuring device to perform a switching loss measuring method. The switching loss measuring device includes a housing, a signal input port, a display screen, a main voltage acquisition channel, an auxiliary voltage acquisition channel, a main current acquisition channel, and a processor. The signal input port and the display screen are respectively disposed on the housing. The main voltage acquisition channel, the auxiliary voltage acquisition channel, and the main current acquisition channel are electrically connected to the signal input port within the housing. The processor is disposed within the housing and is electrically connected to the main voltage acquisition channel, the auxiliary voltage acquisition channel, and the main current acquisition channel.

[0037] The auxiliary voltage acquisition channel includes at least one voltage channel. The voltage level acquired by the at least one voltage channel is lower than the voltage level acquired by the main voltage acquisition channel, and the voltage levels acquired by the at least one voltage channel decrease sequentially.

[0038] An input voltage and an input current are input to the processor through the signal input port. The input voltage is input through the main voltage acquisition channel and the at least one voltage channel, and the input current is input through the main current acquisition channel. The processor generates measurement time data through a switching timing measurement program. Based on the measurement time data, the processor extracts the input voltage and the input current corresponding to the measurement time data from the main voltage acquisition channel and the main current acquisition channel to calculate a switching loss data. Based on the measurement time data, the processor extracts the input voltage and the corresponding input current corresponding to the measurement time data from the at least one voltage channel to calculate a conduction loss data. The processor adds the switching loss data and the conduction loss data to obtain a switching loss data, and the processor controls the display screen to display the switching loss data.

[0039] Preferably, the aforementioned switch switching loss measuring device further includes:

[0040] An auxiliary current acquisition channel is disposed within the housing and electrically connected to the signal input port; the auxiliary current acquisition channel includes at least one current channel; the current level acquired by the at least one current channel is lower than the current level acquired by the main current acquisition channel, and the current levels acquired by the at least one current channel decrease sequentially; the input current is input to the processor through the at least one current channel.

[0041] The processor extracts the input current corresponding to the measurement time data from the at least one current channel, and calculates the conduction loss data by matching the input voltage extracted from the at least one voltage channel.

[0042] Preferably, as in the aforementioned switch switching loss measurement device, the measurement time data includes an on time data, an on time data, and an off time data;

[0043] Based on the turn-on time data, the processor extracts the input voltage of the main voltage acquisition channel during one turn-on time as a turn-on voltage, and extracts the input current of the main current acquisition channel during the turn-on time as a turn-on current; and based on the turn-off time data, the processor extracts the input voltage of the main voltage acquisition channel during one turn-off time as a turn-off voltage, and extracts the input current of the main current acquisition channel during the turn-off time as a turn-off current; the processor multiplies the turn-on voltage and the turn-off current to obtain turn-on loss data, and multiplies the turn-off voltage and the turn-off current to obtain turn-off loss data; the processor further adds the turn-on loss data and the turn-off loss data to obtain the switching loss data;

[0044] The processor controls the display screen to show the enabled loss data and the disabled loss data.

[0045] The switching loss data measured by the switching loss measurement method and measuring device of this invention can more accurately calculate the energy loss of switching a switch, because the main voltage acquisition channel and the auxiliary voltage acquisition channel have different acquisition voltage levels, and therefore different voltage resolution ranges. By resolving the different input voltage levels, this invention can more accurately acquire the input voltage to more accurately calculate the energy loss of switching the switch. Attached Figure Description

[0046] Figure 1 This is a flowchart of a first embodiment of a switch switching loss measurement method of the present invention.

[0047] Figure 2 This is another flowchart of the first embodiment of the switch switching loss measurement method of the present invention.

[0048] Figure 3 This is a flowchart of a second embodiment of the switch switching loss measurement method of the present invention.

[0049] Figure 4 This is another flowchart of the second embodiment of the switching loss measurement method of the present invention.

[0050] Figure 5 This is a block diagram of a first embodiment of a switch switching loss measurement device of the present invention.

[0051] Figure 6 This is a block diagram of a second embodiment of the switch switching loss measuring device of the present invention.

[0052] Figure 7 This is another block diagram of the second embodiment of the switch switching loss measuring device of the present invention.

[0053] Figure 8 This is a schematic diagram of the appearance of the first embodiment of the switch switching loss measuring device of the present invention.

[0054] Figure 9 A circuit diagram of a switching power supply circuit for verifying the present invention.

[0055] Figure 10A This is a schematic diagram illustrating the present invention of displaying a voltage signal on a display screen.

[0056] Figure 10B This is a schematic diagram of the present invention displaying a current signal on the display screen.

[0057] Figure 10C This is a schematic diagram of the present invention displaying a total power loss signal on the display screen.

[0058] Figure 10DThis is a schematic diagram illustrating the present invention of displaying a small voltage level signal on the display screen.

[0059] Figure 10E This is a schematic diagram illustrating the present invention of displaying a small power loss signal on the display screen.

[0060] Figure 11 This is a schematic diagram showing the results of the switch switching loss measurement device of the present invention.

[0061] Figure 12A This is a schematic diagram of an oscilloscope displaying a voltage signal.

[0062] Figure 12B This is a schematic diagram showing a current signal displayed on the oscilloscope.

[0063] Figure 12C This is a schematic diagram showing the total power loss signal displayed on the oscilloscope.

[0064] Figure 13 This is a schematic diagram showing the results of calculating the energy loss during switching on this oscilloscope. Detailed Implementation

[0065] The following description, in conjunction with the accompanying drawings and the first embodiment of the present invention, further illustrates the technical means employed by the present invention to achieve its intended purpose.

[0066] This invention discloses a method for measuring switch switching losses, executed by a switch switching loss measuring device. This device acquires an input voltage and an input current of an input signal and calculates the energy loss of switching a switch according to the method. The energy loss of switching the switch can be divided into an on-loss, an off-loss, and a conduction loss. The on-loss corresponds to the energy loss when the input signal is subjected to the switch being turned on; the off-loss corresponds to the energy loss when the input signal is subjected to the switch being turned off; and the conduction loss corresponds to the energy loss when the input signal is subjected to the switch being turned on. The energy loss of the switch is the sum of the on-loss, off-loss, and conduction losses. Since the on-loss, off-loss, and conduction losses all occur at specific times during different switching states of the switch, they can all be discussed in terms of power, and therefore the energy loss of the switch can also be discussed in terms of power.

[0067] When this switch is switched, the input voltage and current of the input signal typically exhibit significant changes in their respective ranges. For example, when the switch is off, the input voltage might be measured at several hundred volts, while when energized, it might decrease to several hundred millivolts, resulting in a voltage range change equivalent to a thousandfold. Therefore, a high voltage range is needed to capture the input voltage at the instant the switch is turned on and off, while a lower voltage range is needed when the switch is on, to accurately capture the changes in the input voltage under different switching states. The voltage range refers to the voltage range that the switch switching loss measuring device can withstand when capturing the input voltage, and the current range refers to the current range that the switch switching loss measuring device can withstand when capturing the input current.

[0068] Please see Figure 1 As shown, a method for measuring switch switching loss includes the following steps:

[0069] Step S1: Receive an input voltage from a main voltage acquisition channel and an auxiliary voltage acquisition channel of the loss measurement device via a switch, and receive an input current from a main current acquisition channel of the loss measurement device via the same switch. The voltage range acquired by the auxiliary voltage acquisition channel is lower than the voltage range acquired by the main voltage acquisition channel.

[0070] Step S2: Perform a switching timing measurement program on the input voltage received from the main voltage acquisition channel and the input current received from the main current acquisition channel to generate measurement time data.

[0071] Step S3: Based on the measurement time data, extract the input voltage and input current corresponding to the measurement time data from the main voltage acquisition channel and the main current acquisition channel, and calculate a switching loss data. Also, extract the input voltage and input current corresponding to the measurement time data from the auxiliary voltage acquisition channel, and calculate a conduction loss data.

[0072] Step S4: Add the switching loss data and the conduction loss data together to obtain a switch switching loss data.

[0073] The aforementioned voltage range refers to the voltage range that the switching loss measuring device can withstand when acquiring the input voltage. Because the voltage range acquired by the auxiliary voltage acquisition channel is smaller than that acquired by the main voltage acquisition channel, when the input voltage is large, the switching loss measuring device should use the main voltage acquisition channel to acquire the voltage without damaging the auxiliary voltage acquisition channel. Conversely, when the input voltage is small, the switching loss measuring device should use the auxiliary voltage acquisition channel to acquire the voltage to achieve better voltage resolution.

[0074] In practice, the above involves a signal being received by an oscilloscope via a high-voltage probe to become the input voltage. The high-voltage probe first attenuates the high-voltage signal to a voltage range acceptable to the oscilloscope before outputting it to the oscilloscope, which then receives it as the input voltage. Therefore, the voltage signal being measured is not input to the oscilloscope in a time-division multiplexing manner, but rather simultaneously input by the high-voltage probe to both the main voltage acquisition channel and the auxiliary voltage acquisition channel. The difference between the main voltage acquisition channel and the auxiliary voltage acquisition channel is that the main voltage acquisition channel does not experience signal overflow, while the auxiliary voltage acquisition channel, due to the use of a smaller voltage range, will experience signal overflow. This signal overflow corresponds to a shutdown loss data point and therefore does not affect the calculation of the conduction loss data, which will be explained later in the manual.

[0075] The factors affecting voltage and current resolution are the number of bits required for the device to resolve the input voltage and current in the switch loss measurement. For example, an 8-bit switch loss measurement device has (2... 8 =256) different values ​​are used to analyze a voltage range, so the smaller the voltage range of the voltage range, the more finely the device that measures the switching loss of the switch can analyze the changes in the input voltage.

[0076] In addition, the timing measurement of this switch switching is basically the timing measurement method of current oscilloscopes. That is, in order to maintain the timing relationship between the input voltage and the input current, the signal delay time, signal hold time, pulse width, signal offset and other items are analyzed to automatically generate the measurement time data and unify the timing relationship between each voltage acquisition channel and each current acquisition channel.

[0077] In a first embodiment of the switch switching loss measurement method of the present invention, the measurement time data includes an on-time data, a turn-on time data, and an off-time data. The on-time data corresponds to the time when a switch element is turned on, the off-time data corresponds to the time when the switch element is turned off, and the turn-on time data corresponds to the time when the switch element is turned on. The turn-on time of the switch element is after the time when the switch element is turned on and before the time when the switch element is turned off. The switch switching timing measurement is to find the various time points when the input signal corresponds to the on, off, and on states of the switch. The switch element is provided to facilitate the verification of the switch switching loss measurement method of the present invention, and the switch element controls the on, off, and on states of the signal input to the oscilloscope.

[0078] Please see Figure 2 As shown, after defining the turn-on time data, the conduction time data, and the turn-off time data, step S3 of the first embodiment further includes the following steps:

[0079] Step S31: Based on the turn-on time data, extract the input voltage of the main voltage acquisition channel during one turn-on time as a turn-on voltage, and extract the input current of the main current acquisition channel during the turn-on time as a turn-on current. And based on the turn-off time data, extract the input voltage of the main voltage acquisition channel during one turn-off time as a turn-off voltage, and extract the input current of the main current acquisition channel during the turn-off time as a turn-off current.

[0080] Step S32: Multiply the turn-on voltage and the turn-on current to obtain a turn-on loss data, and multiply the turn-off voltage and the turn-off current to obtain a turn-off loss data.

[0081] Step S33: Add the opening loss data and the closing loss data together to obtain the switching loss data.

[0082] Step S34: Based on the conduction time data, extract the input voltage of the auxiliary voltage extraction channel during one conduction time as a conduction voltage, and extract the input current of the main current extraction channel during the conduction time as a conduction current.

[0083] Step S35: Multiply the conduction voltage and the conduction current to obtain the conduction loss data.

[0084] In step S31 above, the reason for sampling the turn-on voltage using the main voltage acquisition channel and the turn-on current using the main current acquisition channel during the turn-on time, and sampling the turn-off voltage and turn-off current using the same main voltage acquisition channel and main current acquisition channel during the turn-off time of the switching element, is that a large voltage level is needed to withstand and sample the input signal due to the large voltage and current changes at the instant the switch is turned on and off. As mentioned above, this so-called large voltage change can be a voltage change of thousands of times. Given that a large voltage change is known to occur, there is no need to use an auxiliary voltage acquisition channel to sample the input signal. Furthermore, in step S32, the unit of the turn-on loss data and the turn-off loss data is watts; that is, multiplying the voltage unit (volt) and the current unit (ampere) yields the power unit (watt).

[0085] In step S34 above, compared with the moment the switch is turned on and off, the input voltage of the switch is smaller when it is on. Therefore, it is more reasonable to use the auxiliary voltage acquisition channel with a smaller voltage level to sample the input voltage when it is on, so that the sampling can have better voltage resolution.

[0086] In this first embodiment, after performing step S4, the following is further included:

[0087] Step S5: Calculate a saturation operating voltage value within the conduction time based on the conduction time data, the conduction voltage, and the conduction current.

[0088] Step S6: Calculate the on-resistance value during the on-time based on the on-time data, the on-voltage, and the on-current.

[0089] Steps S5 and S6 involve calculations based on the conduction time data, after determining the conduction voltage and conduction current. The calculation methods for the conduction resistance and saturation operating voltage will be discussed in detail later in this specification.

[0090] The switching element can be a metal-oxide-semiconductor field-effect transistor (MOSFET) or a bipolar junction transistor (BJT) / insulated-gate bipolar transistor (IGBT). Regarding the estimation of element parameters in steps S5 and S6, for a MOSFET, the on-resistance value in step S6 will be more emphasized, while for a BJT / IGBT, the saturation operating voltage value in step S5 will be more emphasized.

[0091] Please see Figure 3 and Figure 4 As shown, in a second embodiment of the present invention, between step S1 and step S2, the following is further included:

[0092] Step S11: Receive another input current from an auxiliary current acquisition channel of the switching loss measurement device. The current range acquired by the auxiliary current acquisition channel is less than the current range acquired by the main current acquisition channel.

[0093] Furthermore, in this second embodiment, step S3 further includes the following sub-steps:

[0094] Step S31: Based on the turn-on time data, extract the input voltage of the main voltage acquisition channel during the turn-on time as the turn-on voltage, and extract the input current of the main current acquisition channel during the turn-on time as the turn-on current. And based on the turn-off time data, extract the input voltage of the main voltage acquisition channel during the turn-off time as the turn-off voltage, and extract the input current of the main current acquisition channel during the turn-off time as the turn-off current.

[0095] Step S32: Multiply the turn-on voltage and the turn-on current to obtain the turn-on loss data, and multiply the turn-off voltage and the turn-off current to obtain the turn-off loss data.

[0096] Step S33: Add the opening loss data and the closing loss data together to obtain the switching loss data.

[0097] Step S34': Based on the conduction time data, extract the input voltage of the auxiliary voltage acquisition channel during one conduction time as a conduction voltage, and extract the input current of the auxiliary current acquisition channel during the conduction time as a conduction current.

[0098] Step S35': Multiply the conduction voltage and the conduction current to obtain the conduction loss data.

[0099] In this second embodiment, the current range refers to the current range that the switching loss measuring device can withstand when capturing the input current. When the input current is large, the switching loss measuring device should use the main current acquisition channel to capture the current without damaging the auxiliary current acquisition channel. When the input current is small, the switching loss measuring device should use the auxiliary current acquisition channel to capture the current to achieve better current resolution.

[0100] When the 8-bit switching loss measuring device analyzes a current range with 256 different values, the smaller the current range of the current range, the more precisely the device can analyze the changes in the input current.

[0101] In this second embodiment, the auxiliary voltage acquisition channel further includes multiple voltage channels, and the auxiliary current acquisition channel further includes multiple current channels. The voltage levels acquired by these voltage channels are lower than the voltage levels acquired by the main voltage acquisition channel, and the voltage levels acquired by these voltage channels decrease sequentially. The current levels acquired by these current channels are lower than the current levels acquired by the main current acquisition channel, and the current levels acquired by these current channels decrease sequentially. According to the levels corresponding to the input voltage and the input current, when the switching element is turned on, the input voltage is sampled from the voltage channel of the corresponding level as the turn-on voltage, and the input current is sampled from the current channel of the corresponding level as the turn-on current, and the turn-on voltage and the turn-on current are multiplied to obtain the conduction loss data.

[0102] The aforementioned sampling of the input voltage as the conduction voltage from the corresponding voltage channel means first sensing whether the input voltage falls within the range of the maximum voltage tolerance range in the voltage channel. For example, the maximum voltage tolerance range in the voltage channel can withstand a range from 150 volts (V) to 50V. If the input voltage is less than 50V at this range, the input voltage is then sensed at a smaller voltage range. The voltage tolerance range of this smaller voltage range is from 100V to 10V. If the input voltage is sensed as 30V, falling within the 100V to 10V range, the input voltage is first sampled at a voltage range within that 100V to 10V range, and then sampled again at a smaller voltage range within the voltage tolerance range, for example, at a voltage range of 50V to 0.5V. Next, since the next voltage level has a voltage tolerance range of 1V to 0.1V, the input voltage is no longer within this tolerance range and therefore does not need to be sampled further. Therefore, the aforementioned corresponding voltage channels refer to the voltage channels with a voltage tolerance range of 100V to 10V and 50V to 0.5V, ensuring that the 30V input voltage can be sampled within the appropriate voltage tolerance range.

[0103] Similarly, the aforementioned sampling of the input current as the conduction current from the corresponding current channel means first sensing whether the input current is within the range of the maximum current carrying capacity of the current channel, then successively decreasing the current channels to determine which current channels have current carrying capacity within which the input current can be sampled, and sampling the input current as the conduction current from the current channels of those corresponding channels. If the input current is sensed to be 3 amps (A), and the decreasing current carrying capacity channels are 10A to 1A, 5A to 1A, and 1A to 0.1A, then the aforementioned corresponding current channels refer to the current channels corresponding to the 10A to 1A and 5A to 1A channels, so that the 3A input current can be captured within the appropriate current carrying capacity range.

[0104] For example, in an 8-bit resolution oscilloscope, a voltage range from 100V to 10V can be divided into 256 values, and the signal can be resolved in 256 equal parts. This resolution is equivalent to (100V-10V) / 256≈0.35V, meaning one resolved value represents approximately 0.35V. As for the 50V to 0.5V voltage range, the resolution is (50V-0.5V) / 256≈0.19V, meaning one resolved value represents approximately 0.19V. From the above example, we can see that the 8-bit resolution changes when the voltage range changes, and the smaller the voltage range, the higher the voltage resolution. Assuming a voltage change of 5V from 30V to 25V needs to be analyzed, approximately 5 / 0.35 ≈ 14 values ​​can be sensed for this 5V change in the 100V to 10V voltage range, while approximately 5 / 0.19 ≈ 26 values ​​can be sensed for the same change in the 50V to 0.5V voltage range. This shows that the smaller the voltage range being analyzed, the clearer the voltage change can be. Similarly, the smaller the current range being analyzed, the clearer the current change can be.

[0105] In this second embodiment, when conduction occurs, the auxiliary voltage acquisition channel is used to acquire the conduction voltage. More precisely, these voltage channels are used to acquire the input voltage with different voltage ranges and corresponding voltage resolutions. After acquiring the input voltage separately, the acquired data for each voltage range yields different calculation results. The processor reassembles the calculation results from the signals at different resolutions to obtain a more accurate waveform and value of the input voltage. The more resolutions the processor samples in each voltage range, the more samples it has to reassemble and reproduce the waveform and value of the input voltage, thus enabling more accurate sensing of the conduction voltage. Similarly, the conduction current can also be acquired through these current channels with different current ranges and corresponding current resolutions, allowing the processor to more accurately reproduce the waveform and value of the input current when reassembling the calculation results.

[0106] Please see Figure 5As shown, a switching loss measurement device performs a switching loss measurement method. The device includes a housing, a signal input port 10, a display screen 20, a main voltage acquisition channel 31, an auxiliary voltage acquisition channel 32, a main current acquisition channel 33, and a processor 40. The signal input port 10 and the display screen 20 are respectively disposed on the housing. The main voltage acquisition channel 31, the auxiliary voltage acquisition channel 32, and the main current acquisition channel 33 are electrically connected to the signal input port 10 within the housing. The processor 40 is disposed within the housing and is electrically connected to the main voltage acquisition channel 31, the auxiliary voltage acquisition channel 32, and the main current acquisition channel 33.

[0107] The auxiliary voltage acquisition channel 32 includes at least one voltage channel. The voltage range acquired by the at least one voltage channel is lower than the voltage range acquired by the main voltage acquisition channel 31, and the voltage ranges acquired by the at least one voltage channel decrease sequentially. The acquired voltage range refers to the voltage range that the switching loss measuring device can withstand when acquiring an input voltage.

[0108] In a first embodiment of the switching loss measurement device, the at least one voltage channel includes a first voltage channel 321, a second voltage channel 322, and an Nth voltage channel 32N. The Nth voltage channel 32N is the voltage channel with the smallest voltage range that it can withstand among the at least one voltage channel.

[0109] The input voltage and input current are input to the processor 40 through the signal input port 10. The input voltage is input to the processor 40 through the main voltage acquisition channel 31 and the at least one voltage channel, and the input current is input to the processor 40 through the main current acquisition channel 33. The processor 40 generates measurement time data through a switching timing measurement program. Based on the measurement time data, the processor 40 extracts the input voltage and input current corresponding to the measurement time data from the main voltage acquisition channel 31 and the main current acquisition channel 33 to calculate a switching loss data. Based on the measurement time data, the processor 40 extracts the input voltage and corresponding input current corresponding to the measurement time data from the at least one voltage channel to calculate a conduction loss data. The processor 40 adds the switching loss data and the conduction loss data to obtain a switching loss data, and the processor 40 controls the display screen 20 to display the switching loss data.

[0110] Please see Figure 6 and Figure 7As shown, in a second embodiment of the present invention, the switch switching loss measuring device further includes an auxiliary current acquisition channel 34. The auxiliary current acquisition channel 34 is disposed within the housing and electrically connected to the signal input port 10. The auxiliary current acquisition channel 34 includes at least one current channel. The current level acquired by the at least one current channel is lower than the current level acquired by the main current acquisition channel 33, and the current levels acquired by the at least one current channel decrease sequentially. The input current is input to the processor 40 through the at least one current channel. The acquired current level refers to the current range that the switch switching loss measuring device can withstand when acquiring the input current.

[0111] In detail, the at least one current channel includes a first current channel 341, a second current channel 342, and an Nth current channel 34N. The Nth current channel 34N is the current channel with the smallest current carrying capacity among the at least one current channel.

[0112] In addition, in this second embodiment, the processor 40 further includes a switch switching timing measurement unit 41, a switching loss unit 42, a conduction loss unit 43, a switch switching total loss unit 44, and a parameter estimation unit 45.

[0113] The input voltage and the input current are input to the processor 40 through the signal input port 10. The input voltage is input to the processor 40 through the main voltage acquisition channel 31 and the at least one voltage channel, and the input current is input to the processor 40 through the main current acquisition channel 33 and the at least one current channel. The processor 40 generates the measurement time data through the switch switching timing measurement program of the switch switching timing measurement unit 41. Based on the measurement time data, the processor 40 extracts the input voltage and the input current corresponding to the measurement time data from the main voltage acquisition channel 31 and the main current acquisition channel 33, and calculates a switching loss data through the switching loss unit 42. Based on the measurement time data, the processor 40 extracts the input voltage and the input current corresponding to the measurement time data from the at least one voltage channel and the at least one current channel, and calculates the conduction loss data through the conduction loss unit 43. The processor 40 calculates the switch switching loss data through the switch switching total loss unit 44 based on the switch switching loss data and the conduction loss data, and the processor 40 controls the display screen 20 to display the switch switching loss data.

[0114] The measurement time data includes an on-time data, a turn-on time data, and an off-time data. The on-time data corresponds to the time when a switching element is turned on, the off-time data corresponds to the time when the switching element is turned off, and the turn-on time data corresponds to the time when the switching element is turned on. The turn-on time of the switching element occurs after the time the switching element is turned on and before the time the switching element is turned off. This switching element is provided for verification purposes of the switch switching loss measurement device of the present invention, and the switching element controls the on / off and conduction of the signal input to the oscilloscope.

[0115] Based on the turn-on time data, the processor 40 extracts the input voltage of the main voltage extraction channel 31 during a turn-on time as a turn-on voltage, and extracts the input current of the main current extraction channel 33 during the turn-on time as a turn-on current. Based on the turn-off time data, the processor 40 extracts the input voltage of the main voltage extraction channel 31 during a turn-off time as a turn-off voltage, and extracts the input current of the main current extraction channel 33 during the turn-off time as a turn-off current. The processor 40 further multiplies the turn-on voltage and the turn-on current to obtain turn-on loss data, and multiplies the turn-off voltage and the turn-off current to obtain turn-off loss data. The processor 40 adds the turn-on loss data and the turn-off loss data to obtain the switching loss data, and the processor 40 controls the display screen 20 to display the turn-on loss data and the turn-off loss data.

[0116] Furthermore, based on the conduction time data, the processor 40 extracts the input voltage of the auxiliary voltage extraction channel 32 during one conduction time as a conduction voltage, and extracts the input current of the auxiliary current extraction channel 34 during the same conduction time as a conduction current. The processor 40 further multiplies the conduction voltage and the conduction current to obtain the conduction loss data, and the processor 40 controls the display screen 20 to display the conduction loss data.

[0117] The processor 40 further calculates a saturation operating voltage value and a conduction resistance value within the conduction time based on the conduction time data, the conduction voltage and the conduction current through the parameter estimation unit 45, and the processor 40 controls the display screen 20 to display the saturation operating voltage value and the conduction resistance value.

[0118] In this first embodiment, the switch switching loss measurement device is an 8-bit resolution oscilloscope. This oscilloscope can analyze an input voltage and an input current using 256 different values. When the input voltage and current change more than a thousandfold due to the opening, closing, and tripping of a switch, the oscilloscope cannot simultaneously and accurately present the values ​​and waveforms of the input voltage and current using 256 different values. For example, it cannot simultaneously and accurately present the values ​​and waveforms between a hundred volts and a hundred millivolts. Therefore, when the switch is open and closed, the processor 40 samples the input voltage of the main current acquisition channel 33 and the input current of the main current acquisition channel 33 to obtain the opening loss data and the closing loss data from high voltage and high current ranges.

[0119] The processor 40 further reads the input voltage and input current corresponding to the measurement time data from the at least one voltage channel and the at least one current channel to calculate a conduction loss data based on the measurement time data. That is, when the input voltage and input current decrease, samples of different voltage levels are obtained through the at least one voltage channel, such as the first voltage channel 321, the second voltage channel 322, and the Nth voltage channel 32N, and samples of different current levels are obtained through the first current channel 341, the second current channel 342, and the Nth current channel 34N. The processor 40 then performs a calculation result reconstruction based on all the samples of different voltage and different current levels to reconstruct the calculation results from signals of different resolutions, so that the input voltage at conduction time is more accurately captured as the conduction voltage and the input current is more accurately captured as the conduction current.

[0120] Please see Figure 8 and Figure 9 As shown, Figure 8 This is a schematic diagram of the appearance of the first embodiment of the switch switching loss measuring device of the present invention. The display screen 20 of the switch switching loss measuring device is disposed on the housing 5. The display screen 20 displays the waveforms of the input voltage and the input current of an input signal. The signal input port 10 further includes a first input port 11, a second input port 12, and a third input port 13. The first input port 11 is electrically connected to the main voltage acquisition channel 31, the second input port 12 is electrically connected to the auxiliary voltage acquisition channel 32, and the third input port 13 is electrically connected to the main current acquisition channel 33. In addition, the first input port 11 and the second input port 12 are each electrically connected to a high voltage probe, and the third input port 13 is electrically connected to a current probe.

[0121] Figure 9To verify the present invention, a switching power supply circuit is described. This switching power supply circuit uses a diode bridge B1 to convert alternating current (AC) to direct current (DC). Specifically, the AC power is input to the diode bridge B1 via a live wire and a neutral wire. The DC power passes through a metal-oxide-semiconductor field-effect transistor (MOSFET). This MOSFET is controlled by a feedback and switching control module, and the gate of this MOSFET is connected to the feedback and switching control module. In this embodiment, the switching element is a switch within the feedback and switching control module. This switch controls the drive voltage supplied to the gate of the MOSFET by the feedback and switching control module, thereby controlling the duration of the MOSFET's on and off states. The high-voltage probes electrically connected to the first input port 11 and the second input port 12 are both electrically connected to the drain and source terminals of the MOSFET to measure the voltage. The current probe electrically connected to the third input port 13 is electrically connected to the current flowing from the drain terminal of the MOSFET into the source terminal. Figure 9 The output port (Vout) is a power output port for verifying the switching power supply circuit of the present invention.

[0122] Please see Figures 10A to 11 As shown, the display screen 20 of the first embodiment of the present invention respectively presents Figures 10A to 10E The different signals shown. Figure 10A The display screen 20 shows a voltage signal 1. Figure 10B The corresponding display shows a current signal 2. Figure 10C The corresponding total power loss signal 3 was displayed. Figure 10D The corresponding voltage signal 4 was displayed, and Figure 10E The corresponding small-level power loss signal 5 is displayed, which corresponds to the small-level voltage signal 4. Figures 10A to 10E The display also shows a first time point T1, a second time point T2, and a third time point T3. The first time point T1 corresponds to the time the switch is turned on, the third time point T3 corresponds to the time it is turned off, and the second time point T2 corresponds to the time the switch is turned on. The value of voltage signal 1 at the first time point T1 is the on-state voltage, the value of voltage signal 1 at the second time point T2 is the on-state voltage, and the value of voltage signal 1 at the third time point T3 is the off-state voltage. The value of current signal 2 at the first time point T1 is the on-state current, the value of current signal 2 at the second time point T2 is the on-state current, and the value of current signal 2 at the third time point T3 is the off-state current.

[0123] like Figure 10A and Figure 10B As shown, in another embodiment, the processor 40 further provides a low level 110, a middle level 120, and a high level 130 for both the input voltage and the input current. The low level 110, the middle level 120, and the high level 130 are adjustable values, not fixed values. This embodiment presents only one set value for the low level 110, the middle level 120, and the high level 130, rather than absolute values.

[0124] If the reference value (i.e., 0 volts) in the input voltage amplitude is 0% and the maximum value in the input voltage amplitude is 100%, then the lower level 110 of the input voltage is at 5% of the input voltage amplitude, the middle level 120 of the input voltage is at 10% of the input voltage amplitude, and the higher level 130 of the input voltage is at 90% of the input voltage amplitude. Similarly, if the reference value (i.e., 0 amperes) in the input current amplitude is 0% and the maximum value in the input current amplitude is 100%, then the lower level 110 of the input current is at 5% of the input current amplitude, the middle level 120 of the input current is at 30% of the input current amplitude, and the higher level 130 of the input current is at 60% of the input current amplitude.

[0125] Furthermore, each of the first time point T1, the second time point T2, and the third time point T3 constitutes a time period. Specifically, the first time point T1 begins when the input current rises to its low level 110 and ends when the input voltage drops to its low level 110. The third time point T3 begins when the input voltage rises to its low level 110 and ends when the input current drops to its low level 110. The second time point T2 begins at the end of the first time point T1, and the end of the second time point T2 begins at the start of the third time point T3.

[0126] Furthermore, the average results of the turn-on loss data, the turn-off loss data, and the turn-on loss data are calculated as follows:

[0127] Integrating the energy loss within the first time point T1, we get an energy loss for turning on; integrating the energy loss within the second time point T2, we get an energy loss for turning on; and integrating the energy loss within the third time point T3, we get an energy loss for turning off.

[0128] Set a switch switching cycle of 100 as the time unit for one cycle of signal repetition, for example... Figure 10A and Figure 10B As shown, the switching cycle 100 can be the time from the start of the first time point T1 to the start of the next first time point T1.

[0129] The opening loss energy is divided by the cycle time unit to calculate the opening loss data, the conduction loss energy is divided by the cycle time unit to calculate the conduction loss data, and the closing loss energy is divided by the cycle time unit to calculate the closing loss data.

[0130] The energy loss within the first time point T1 mentioned above is the energy loss from activation, which can be expressed by the following formula:

[0131]

[0132] in, and Within this first time point T1, it will change over time. And change. The instantaneous voltage at the terminals of the switching element, and This refers to the instantaneous current flowing through the terminals of the switching element. This instantaneous voltage can be the voltage between the drain and source of the MOSFET, or in another embodiment, the voltage between the collector and emitter of the BJT. This instantaneous current can be the current between the drain and source of the MOSFET, or in another embodiment, the current between the collector and emitter of the BJT.

[0133] When integrating the energy loss within the first time point T1 as the energy loss during activation, the instantaneous voltage between the beginning and end of the first time point T1 is... and the instantaneous current These are the turn-on voltage and the turn-on current, respectively. Integrating the energy loss within the second time point T2 as the conduction loss energy, the instantaneous voltage between the beginning and end of the second time point T2 is... and the instantaneous current These are the on-state voltage and the on-state current, respectively. Integrating the energy loss within the third time point T3 as the energy lost during shutdown, the instantaneous voltage between the beginning and end of the third time point T3 is... and the instantaneous current These are the shutdown voltage and the shutdown current, respectively.

[0134] The turn-on loss data, conduction loss data, and turn-off loss data calculated here are based on this cycle time unit, and therefore represent the average result. However, Figure 10C The total power loss signal 3 shown in the image is... Figure 10EThe power loss signal 5 displayed is a real-time result. That is, the total power loss signal 3 is obtained by multiplying the voltage signal 1 displayed in real time by the current signal 2, and the power loss signal 5 of the small gear is obtained by multiplying the voltage signal 4 of the small gear displayed in real time by the current signal 2.

[0135] Furthermore, the detailed calculations for the saturation operating voltage and the on-resistance are as follows:

[0136]

[0137]

[0138] in, This is the saturation operating voltage value. This is the on-resistance value. This is the conduction loss data. This is the average value of the conduction current within the second time point T2, and This is the square of the root mean square value of the conduction current within the second time point T2. Therefore, after obtaining the conduction time data and its corresponding conduction loss energy and conduction loss data through measurement, the saturation operating voltage value and the conduction resistance value can be calculated using the above formula.

[0139] Figure 11 For the corresponding Figures 10A to 10E The obtained data displays the average result of the turn-on loss data, the conduction loss data, and the turn-off loss data calculated in the other embodiment described above. (Comparison with conventional techniques) Figures 12A to 13 It can be observed that the averaged conduction loss data calculated by this invention is a positive number, which is more reasonable and accurate than a negative number. This is because this invention uses the higher voltage resolution of the smaller voltage level of the auxiliary voltage acquisition channel 32 to analyze the conduction voltage at the second time point T2. The small-level power loss signal 5 represents the result of multiplying the conduction voltage and the conduction current when the switching element of the switching power supply circuit is turned on. The small-level power loss signal 5 corresponds to the total power loss signal 3 at that time point. Figure 10D The conduction voltage presented by the small voltage signal 4 at the second time point T2 is relatively... Figure 10A The conduction voltage presented by voltage signal 1 at the second time point T2 is more accurate. Through the smaller voltage range acquisition of the auxiliary voltage acquisition channel 32 of this invention, the smaller voltage range voltage signal 4 has better voltage resolution. (Comparison) Figure 10A and Figure 10D It can be observed that the signal error obtained from the lower voltage signal 4 is smaller than the signal error obtained from the voltage signal 1.

[0140] according to Figure 11As shown, with the improved resolution of the on-state voltage, the on-state loss calculated by this invention is 32.35 milliwatts (mW). This invention adds the on-state loss of 52.22 mW, the off-state loss of 26.63 mW, and the on-state loss of 32.35 mW to obtain the switching loss of 111.2 mW, i.e., (52.22 + 26.63 + 32.35 = 111.2) mW. Based on the on-time data, the on-state voltage, the on-state current, and the aforementioned formula, this invention derives the saturation operating voltage of 370.6 millivolts (mV) and the on-state resistance of 684.0 milliohms (mΩ) from the on-state loss data obtained from the on-state time of the switching element.

[0141] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for measuring switching loss, characterized in that, include: Step S1: Receive an input voltage from a main voltage acquisition channel and an auxiliary voltage acquisition channel of a loss measurement device by switching a switch, and receive an input current from a main current acquisition channel of the loss measurement device by the same switch; wherein, the voltage range acquired by the auxiliary voltage acquisition channel is lower than the voltage range acquired by the main voltage acquisition channel. Step S2: Perform a switching timing measurement program on the input voltage received from the main voltage acquisition channel and the input current received from the main current acquisition channel to generate measurement time data. Step S3: Based on the measurement time data, extract the input voltage and input current corresponding to the measurement time data from the main voltage acquisition channel and the main current acquisition channel, and calculate a switching loss data. Also, extract the input voltage and input current corresponding to the measurement time data from the auxiliary voltage acquisition channel, and calculate a conduction loss data. Step S4: Add the switching loss data and the conduction loss data together to obtain a switch switching loss data.

2. The method for measuring switching loss according to claim 1, characterized in that, The measurement time data includes an on-time data, a conduction time data, and an off-time data; Furthermore, step S3 includes the following sub-steps: Step S31: Based on the turn-on time data, extract the input voltage of the main voltage acquisition channel during one turn-on time as a turn-on voltage, and extract the input current of the main current acquisition channel during the turn-on time as a turn-on current; and based on the turn-off time data, extract the input voltage of the main voltage acquisition channel during one turn-off time as a turn-off voltage, and extract the input current of the main current acquisition channel during the turn-off time as a turn-off current; Step S32: Multiply the turn-on voltage and the turn-on current to obtain a turn-on loss data, and multiply the turn-off voltage and the turn-off current to obtain a turn-off loss data; Step S33: Add the opening loss data and the closing loss data together to obtain the switching loss data.

3. The method for measuring switching loss according to claim 2, characterized in that, Step S3 further includes the following sub-steps: Step S34: Based on the conduction time data, extract the input voltage of the auxiliary voltage extraction channel during one conduction time as a conduction voltage, and extract the input current of the main current extraction channel during the conduction time as a conduction current. Step S35: Multiply the conduction voltage and the conduction current to obtain the conduction loss data.

4. The method for measuring switching loss according to claim 2, characterized in that, Between step S1 and step S2, the following is further included: Step S11: Receive another input current from an auxiliary current acquisition channel of the loss measurement device via the switch; wherein the current range acquired by the auxiliary current acquisition channel is less than the current range acquired by the main current acquisition channel; Furthermore, step S3 includes the following sub-steps: Step S34': Based on the conduction time data, extract the input voltage of the auxiliary voltage acquisition channel during one conduction time as a conduction voltage, and extract the input current of the auxiliary current acquisition channel during the conduction time as a conduction current; Step S35': Multiply the conduction voltage and the conduction current to obtain the conduction loss data.

5. The method for measuring switching loss according to claim 3 or 4, characterized in that, After performing step S4, the following steps are further included: Step S5: Calculate a saturation operating voltage value within the conduction time based on the conduction time data, the conduction voltage, and the conduction current; Step S6: Calculate the on-resistance value during the on-time based on the on-time data, the on-voltage, and the on-current.

6. The method for measuring switching loss according to claim 3, characterized in that, This auxiliary voltage acquisition channel further includes multiple voltage channels; Among them, the voltage level captured by the multiple voltage channels is lower than the voltage level captured by the main voltage acquisition channel, and the voltage levels captured by the multiple voltage channels decrease sequentially. Specifically, according to the gear corresponding to the input voltage, when a switching element is turned on, the input voltage is sampled from the voltage channel of the corresponding gear as the turn-on voltage, and the turn-on voltage and the turn-on current are multiplied to obtain the turn-on loss data.

7. The method for measuring switching loss according to claim 4, characterized in that, The auxiliary voltage acquisition channel further includes multiple voltage channels, and the auxiliary current acquisition channel further includes multiple current channels; Among them, the voltage level captured by the multiple voltage channels is lower than the voltage level captured by the main voltage acquisition channel, and the voltage levels captured by the multiple voltage channels decrease sequentially. Among them, the current level captured by the multiple current channels is smaller than the current level captured by the main current capturing channel, and the current levels captured by the multiple current channels decrease sequentially. Specifically, according to the corresponding gears of the input voltage and the input current, when a switching element is turned on, the input voltage is sampled from the voltage channel of the corresponding gear as the on-state voltage, and the input current is sampled from the current channel of the corresponding gear as the on-state current. The on-state voltage and the on-state current are then multiplied to obtain the conduction loss data.

8. A device for measuring switching loss, characterized in that, include: A shell; A signal input port is located on this housing; A display screen is mounted on this casing; A main voltage acquisition channel is disposed inside the housing and electrically connected to the signal input port; An auxiliary voltage acquisition channel is disposed inside the housing and electrically connected to the signal input port; A main current acquisition channel is disposed inside the housing and electrically connected to the signal input port; and A processor is disposed within the housing, electrically connected to the display screen, and electrically connected to the main voltage acquisition channel, the auxiliary voltage acquisition channel, and the main current acquisition channel, respectively. The auxiliary voltage acquisition channel includes at least one voltage channel; the voltage level acquired by the at least one voltage channel is lower than the voltage level acquired by the main voltage acquisition channel, and the voltage levels acquired by the at least one voltage channel decrease sequentially. An input voltage and an input current are input to the processor through the signal input port. The input voltage is input to the processor through the main voltage acquisition channel and the at least one voltage channel, and the input current is input to the processor through the main current acquisition channel. The processor generates measurement time data through a switching timing measurement program. Based on the measurement time data, the processor extracts the input voltage and the input current corresponding to the measurement time data from the main voltage acquisition channel and the main current acquisition channel to calculate a switching loss data. Based on the measurement time data, the processor extracts the input voltage and the corresponding input current corresponding to the measurement time data from the at least one voltage channel to calculate a conduction loss data. The processor adds the switching loss data and the conduction loss data to obtain a switching loss data, and the processor controls the display screen to display the switching loss data.

9. The switching loss measuring device according to claim 8, characterized in that, Further includes: An auxiliary current acquisition channel is disposed within the housing and electrically connected to the signal input port; the auxiliary current acquisition channel includes at least one current channel; the current level acquired by the at least one current channel is lower than the current level acquired by the main current acquisition channel, and the current levels acquired by the at least one current channel decrease sequentially; the input current is input to the processor through the at least one current channel. The processor extracts the input current corresponding to the measurement time data from the at least one current channel, and calculates the conduction loss data by matching the input voltage extracted from the at least one voltage channel.

10. The switching loss measuring device according to claim 8 or 9, characterized in that, The measurement time data includes an on-time data, a conduction time data, and an off-time data; Based on the turn-on time data, the processor extracts the input voltage of the main voltage acquisition channel during one turn-on time as a turn-on voltage, and extracts the input current of the main current acquisition channel during the turn-on time as a turn-on current; and based on the turn-off time data, the processor extracts the input voltage of the main voltage acquisition channel during one turn-off time as a turn-off voltage, and extracts the input current of the main current acquisition channel during the turn-off time as a turn-off current; the processor multiplies the turn-on voltage and the turn-off current to obtain turn-on loss data, and multiplies the turn-off voltage and the turn-off current to obtain turn-off loss data; the processor further adds the turn-on loss data and the turn-off loss data to obtain the switching loss data; The processor controls the display screen to show the enabled loss data and the disabled loss data.

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