[0057] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is a part of the embodiments of the present invention, not all the embodiments. The components of the embodiments of the present invention generally described and illustrated in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of the present invention.
[0058] Taking into account the problems of unadjustable test temperature, single drive signal, unadjustable switching frequency or input voltage, and inflexible load configuration when using a dual-pulse platform in the prior art for device testing, based on this, the embodiment of the present invention provides a The device testing system and method are described below through embodiments.
[0059] The embodiment of the present invention provides a device testing system, such as figure 1 As shown, the system includes: a power input unit 1, a load unit 2, a measuring unit 3, a heating unit 4, a host computer 5 and a device under test 6. The power input unit 1 is connected to the device under test 6 for 6 power supply;
[0060] The upper computer 5 is connected to the device under test 6. The device under test 6 includes a drive circuit 7. The upper computer 5 transmits a preset drive signal to the drive circuit 7 to control the on and off of the drive circuit 7;
[0061] The load unit 2 is connected to the drive circuit 7, and is used to adjust the current change rate of the drive circuit 7 when the drive circuit 7 is turned on;
[0062] The measuring unit 3 is placed on the driving circuit 7 for measuring the voltage and current flowing through the driving circuit 7;
[0063] The heating unit 4 is connected to the driving circuit 7 for heating the driving circuit 7 to a preset temperature value.
[0064] Such as figure 2 As shown, the power input unit 1 includes: a power supply 101, a circuit breaker 102, a current-limiting resistor 103, a rectifier bridge 104, and a supporting capacitor 105. The power supply 101, the circuit breaker 102, the current-limiting resistor 103, and the primary adjustable isolation transformer 106 are connected in series to form the primary In the current limiting circuit, the secondary adjustable isolation transformer 107 is connected to the first input terminal of the rectifier bridge 104, the second output terminal of the secondary isolation transformer 107 is connected to the second input terminal of the rectifier bridge 104, and the first output of the rectifier bridge 104 The terminal is connected to one end of the supporting capacitor 105, and the second output terminal of the rectifier bridge 104 is connected to the other end of the supporting capacitor 105.
[0065] Among them, the power source 101 refers to an AC power grid, and the circuit breaker 102 is used to connect the power source 101 to the system. The current-limiting resistor 103 can play a role in limiting the current during the initial charging and when the device under test 6 is short-circuited. The device test system is different from the power platform. The switching device only operates a few times on the device test system, so the relative difference of the switching device The power is very small, the resistance value of the current limiting resistor 103 can be selected by the following formula (1):
[0066]
[0067] In formula (1), k is the effective power coefficient, generally 0.01; Pmax is the maximum power of the device under test, and Ug is the effective value of the power supply voltage.
[0068] The adjustable isolation transformer is divided into a primary adjustable isolation transformer 106 and a secondary adjustable isolation transformer 107, which play the role of boosting and isolation. In the isolation transformer, the primary and secondary sides of the electrical are completely insulated, and the circuit is also isolated; the use of an isolation transformer to suspend the secondary to the ground can only be used in applications where the power supply range is small and the line is short. The capacitance current to the ground of the system is too small to cause personal injury, which can not only protect the equipment, but also protect personal safety. In addition, the isolation transformer can also change the voltage, such as changing the AC voltage of 15V to the AC voltage of 220V.
[0069] The rectifier bridge 104 is used to rectify alternating current into direct current, and the rated current of the rectifier bridge 104 can be selected as 2% of the maximum current of the device under test. The supporting capacitor 105 is the energy source when the switching device is operating, and the appropriate capacitance value can be selected by the following formula (2):
[0070]
[0071] In formula (2), t is the pulse test time length, generally 0.002; Udcmax is the maximum DC test voltage of the device under test, and Pmax is the maximum power of the device under test.
[0072] Such as image 3 As shown, the driving circuit 7 includes a diode 701 and a switching device 702. The drain 7021 of the switching device is connected to the positive electrode of the supporting capacitor 105, the source 7022 of the switching device is connected to the negative electrode of the supporting capacitor 105, and the gate 7023 of the switching device is connected to the upper side. The device 5 is connected, the cathode of the diode 701 is connected to the drain 7021 of the switching device, and the anode of the diode 701 is connected to the source 7021 of the switching device.
[0073] Such as Figure 4 As shown, the diode 701 includes: a first diode 711, a second diode 721, a third diode 731, a fourth diode 741, a fifth diode 751 and a sixth diode 761, and a switch The device 702 includes a first MOS tube 712, a second MOS tube 722, a third MOS tube 732, and a fourth MOS tube 742. The supporting capacitor 105 includes a first supporting capacitor 1051 and a second supporting capacitor 1052, wherein,
[0074] The drain of the first MOS tube 712 is connected to the anode of the first supporting capacitor 1051, the source is connected to the drain of the second MOS tube 722, and the gate is connected to the host computer 5 through the first photocoupler;
[0075] The cathode of the first diode 711 is connected to the drain of the first MOS tube 712, and the anode is connected to the source of the first MOS tube 712;
[0076] The drain of the second MOS transistor 722 is connected to the source of the first MOS transistor 712, the source is connected to the drain of the third MOS transistor 732, and the gate is connected to the host computer 5 through the second optical coupler;
[0077] The cathode of the second diode 721 is connected to the drain of the second MOS tube 722, and the anode is connected to the source of the second MOS tube 722;
[0078] The drain of the third MOS transistor 732 is connected to the source of the second MOS transistor 722, the source is connected to the drain of the fourth MOS transistor 742, and the gate is connected to the host computer 5 through the third optical coupler;
[0079] The cathode of the third diode 731 is connected to the drain of the third MOS transistor 732, and the anode is connected to the source of the third MOS transistor 732;
[0080] The drain of the fourth MOS transistor 742 is connected to the source of the third MOS transistor 732, the source is connected to the negative electrode of the second supporting capacitor 1052, and the gate is connected to the host computer 5 through the fourth photocoupler;
[0081] The cathode of the fourth diode 741 is connected to the drain of the fourth MOS transistor 742, and the anode is connected to the source of the fourth MOS transistor 742;
[0082] The negative electrode of the first supporting capacitor 1051 is connected to the positive electrode of the second supporting capacitor 1052;
[0083] The cathode of the fifth diode 751 is connected to the drain of the second MOS transistor 752, and the anode is connected to the cathode of the sixth diode 762 and the cathode of the first support capacitor 1051 respectively;
[0084] The anode of the sixth diode is connected to the source of the third MOS transistor.
[0085] The host computer 5 sends a preset drive signal to the gate of the switching device 702 corresponding to the optocoupler for triggering the gate of the switching device 702 to turn on the switching device 702.
[0086] The test pulse is set as Figure 5 As shown, the test pulse is divided into clusters and intra-cluster pulses. One cluster contains multiple intra-cluster pulses. The intra-cluster pulses are composed of multiple intra-cluster single pulses. The time length of the intra-cluster single pulse is K, and the duty cycle It is D, that is, the time ratio of the high-level pulse to the single pulse in the cluster, and the number of repetitions of the single pulse in the cluster N. The time length of the cluster is L, and the number of repetitions of the cluster is M. Therefore, the time length of the cluster can be obtained by the following formula (3):
[0087] L=K×D×N (3)
[0088] K, D, N, S, M can be set by the user according to the actual situation.
[0089] Such as Image 6 As shown, the positive electrode of the load unit 2 is connected to the drain of the third MOS transistor 732, and the negative electrode is connected to the source of the fourth MOS transistor 742.
[0090] The load unit 2 includes: a first inductor 201, a second inductor 202, a first resistor 204, a second resistor 205, a first gear switch 211, a second gear switch 212, a third gear switch 213, and a fourth gear Switch 214, fifth gear switch 215, and sixth gear switch 216;
[0091] The first inductor 201 is connected in series with the first gear switch 211, the second inductor 202 is connected in series with the second gear switch 212, and one end of the first inductor 201, one end of the second inductor 202 and one end of the third gear switch 213 are connected to The first end 221, one end of the first gear switch 211, one end of the second gear switch 212, and the other end of the third gear switch 213 are connected to the second end 222;
[0092] The first resistor 204 is connected in series with the fourth gear switch 214, the second resistor 205 is connected in series with the fifth gear switch 215, and one end of the first resistor 204, one end of the second resistor 205 and one end of the sixth gear switch 216 are connected to The third terminal 223, one end of the fourth gear switch 214, one end of the fifth gear switch 215, and the other end of the sixth gear switch 216 are connected to the fourth terminal 224;
[0093] The second terminal 222 is the positive electrode of the load unit 2, the first terminal 221 is connected to the fourth terminal 224, and the third terminal 223 is the negative electrode of the load unit 2.
[0094] Both the inductance circuit and the resistance circuit are divided into three gear switches. The third gear switch 213 will short-circuit the inductance circuit when closed, and the sixth gear switch 216 will short-circuit the resistance circuit when it is closed. The gear switch is controlled by the upper computer 5. For control, an optical coupler is used to isolate and connect the gear switch, and by transmitting the control signal of the switching power supply, it is used to close and disconnect the gear switch, so as to realize the flexible configuration of the load circuit.
[0095] The inductance values of the first inductor 201 and the second inductor 202 may be 5-10 times different, and the resistance values of the first resistor 204 and the second resistor 205 may also be 5-10 times different, so that the selection space is larger. Among them, the inductance circuit is used to adjust the current rate of change, and the resistance circuit is used to return the current during a single pulse time in the cluster.
[0096] Such as Figure 4 As shown, the measurement unit 3 includes a voltage probe 301 and a current probe 302. The voltage probe 301 includes a first voltage probe group 311, a second voltage probe group 321, a third voltage probe group 331, and a fourth voltage probe group 341, and the current probe 302 Including a first current probe 312 and a second current probe 322;
[0097] The first voltage probe group 311 is placed on the drain and source of the second MOS transistor 722, the second voltage probe group 321 is placed on the drain and source of the third MOS transistor 732, and the third voltage probe group 331 is placed on the drain and source respectively. At the cathode and anode of the fifth diode 751, the fourth voltage probe group 341 is respectively placed at the drain and source of the fourth MOS tube 742;
[0098] The first current probe 312 is placed at the source of the first MOS tube 712, and the second current probe 322 is placed at the source of the third MOS tube 732.
[0099] Such as Figure 7 As shown, the heating unit 4 includes a heating plate 401 and a temperature detecting resistor 402. The heating plate 401 and the temperature detecting resistor 402 are respectively placed on the heat sink of the device under test 6 for heating the heat sink to a preset temperature and detecting and controlling heating. Temperature, in order to realize the function of test temperature adjustable, test the device performance of the switching device 702 in a high temperature environment. Among them, the temperature detecting resistor 402 can be an NTC temperature detecting resistor, which is a thermistor whose resistance value drops rapidly as the temperature rises, and can detect and control the heating temperature. Moreover, the actual size of NTC temperature detection resistors is very flexible. They can be as small as .010 inches or a very small diameter. The maximum size is almost unlimited, but it is usually suitable for less than half an inch.
[0100] Such as Figure 8 As shown, the embodiment of the present invention also provides a device testing method, which specifically includes the following steps S101 to S105:
[0101] S101, build a device testing system including power input unit, load unit, measurement unit, heating unit, upper computer and device under test, where the power input unit is connected to the device under test, the upper computer is connected to the device under test, and the device under test is connected It includes a drive circuit, the load unit is connected with the drive circuit, the measurement unit is placed on the drive circuit, and the heating unit is connected with the device under test.
[0102] S102, heating the device under test to a preset temperature value.
[0103] S103: Adjust the load unit to adjust the current change rate of the drive circuit when the drive circuit is turned on.
[0104] S104: Trigger the host computer to transmit the preset drive signal to the drive circuit to control the on and off of the drive circuit.
[0105] S105: Control the measurement unit to measure the voltage and current flowing through the drive circuit.
[0106] Based on the above analysis, it can be seen that, compared with the simple test using the dual-pulse platform in the laboratory in the related technology, the device test system and method provided by the embodiment of the present invention adopt a flexible load configuration, an adjustable voltage power supply circuit, and an adjustable test temperature. The device test system is used to test the voltage and current values of the switching devices at different voltages and temperatures.
[0107] It should be noted that similar reference numerals and letters indicate similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0108] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated position or position relationship is based on the position or position relationship shown in the drawings, or the position or position relationship usually placed when the product of the invention is used, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying The referred device or element must have a specific orientation, be configured and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.
[0109] In the description of the present invention, it should also be noted that the terms "set", "installation", "connected", and "connected" should be interpreted broadly, unless otherwise clearly specified and limited. For example, it may be a fixed connection. It can also be detachably connected or integrally connected; it can be mechanically or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in the present invention can be understood in specific situations.
[0110] Finally, it should be noted that the above-mentioned embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, but not to limit them. The protection scope of the present invention is not limited thereto, although referring to the foregoing The embodiments describe the present invention in detail. Those skilled in the art should understand that any person skilled in the art can still modify the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention. Or it may be easily conceived of changes, or equivalent replacements of some of the technical features; these modifications, changes or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
