AC power adjustable IGBT module test system and method

Abstract

The invention discloses an AC power adjustable IGBT module test system and method, and belongs to the technical field of electronic device test. The system comprises a first IGBT half-bridge module, a second IGBT half-bridge module and an AC branch. The alternating current output end of the first IGBT half-bridge module and the alternating current output end of the second IGBT half-bridge module are connected through an alternating current branch. The alternating current branch comprises an adjustable resistor unit, the adjustable resistor unit comprises a fixed resistor and a pair of antiparallel thyristors connected with the fixed resistor in parallel, and gate poles of the two thyristors are connected with the output end of the controller. According to the system, the adjustable resistor unit intelligently controlled by the thyristors is connected in series in the alternating current branch, the adjustable resistor unit is formed by connecting the fixed resistor and the pair of antiparallel thyristors in parallel, and the IGBT half-bridge module is cooperatively controlled by controlling the conduction angle and the on-off state of the thyristors, so that the IGBT half-bridge module can be switched on and off. And the loop equivalent resistance of the alternating-current branch is changed steplessly and quickly, so that the continuous adjustment of the alternating-current power is realized.

Description

Technical Field

[0001] This invention relates to the field of electronic device testing technology, and in particular to a testing system and method for IGBT modules with adjustable AC power. Background Technology

[0002] Existing IGBT half-bridge module push-and-pull test systems typically consist of two IGBT half-bridge modules connected by components such as reactors to form a power loop. This system is primarily used to apply electrothermal stress to IGBT devices for reliability assessment and lifespan testing.

[0003] However, such traditional systems have significant drawbacks. The impedance characteristics of their AC circuits are typically fixed, making it difficult to flexibly adjust the AC power and current waveforms output by the system. Therefore, they cannot accurately simulate the complex and variable operating conditions faced by IGBT modules in practical applications (such as pumped storage, motor drives, and wind power converters). For example, in pumped storage power stations, the input power and frequency of the unit operating as a motor need to be adjusted in real time, and traditional push-pull test systems cannot adequately represent this dynamic process, leading to discrepancies between test results and actual conditions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an AC power adjustable IGBT module test system. By adjusting the trigger pulse phase of a pair of anti-parallel thyristors, the equivalent resistance can be changed steplessly and quickly, achieving smooth power regulation.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution: On one hand, the present invention provides an IGBT module test system with adjustable AC power, including a first IGBT half-bridge module, a second IGBT half-bridge module and an AC branch; The AC output terminals of the first IGBT half-bridge module and the second IGBT half-bridge module are connected through an AC branch. The AC branch includes an adjustable resistor unit, which includes a fixed resistor and a pair of anti-parallel thyristors connected in parallel with the fixed resistor. The two ends of the pair of anti-parallel thyristors are respectively connected to the AC output terminal of the first IGBT half-bridge module and the AC output terminal of the second IGBT half-bridge module. The gates of the two thyristors are connected to the output terminal of the controller.

[0006] This invention introduces an adjustable resistor unit intelligently controlled by thyristors connected in series in the AC branch. The adjustable resistor unit consists of a fixed resistor connected in parallel with a pair of anti-parallel thyristors. The structural changes are minor, the cost increases are minimal, but the functionality is significantly improved.

[0007] Optionally, a DC power supply is connected in parallel across the first IGBT half-bridge module or the second IGBT half-bridge module.

[0008] Optionally, both the first IGBT half-bridge module and the second IGBT half-bridge module include IGBT half-bridge sub-modules, and the two IGBT half-bridge sub-modules are connected in series and then connected in parallel with the capacitor. The midpoint between the two IGBT half-bridge sub-modules is the AC output terminal of either the first or second IGBT half-bridge module.

[0009] Optionally, the IGBT half-bridge submodule includes an IGBT chip and a diode connected in anti-parallel to the IGBT chip; In an IGBT half-bridge module, the emitter of the IGBT chip in one IGBT half-bridge sub-module is connected to the collector of the IGBT chip in another IGBT half-bridge sub-module, with the midpoint of the connection being the AC output terminal of the IGBT half-bridge module.

[0010] Optionally, the AC branch may further include a reactor connected in series with the adjustable resistor unit; One end of the reactor is connected to the AC output terminal of the first IGBT half-bridge module or the AC output terminal of the second IGBT half-bridge module, and the other end is connected to the adjustable resistor unit. The equivalent resistance value of the adjustable resistor unit is continuously adjustable between the resistance value of the fixed resistor and zero resistance value.

[0011] Secondly, the present invention provides a testing method for an IGBT module with adjustable AC power, using the system described in the first aspect for testing, the method comprising: The controller controls the first IGBT half-bridge module and the second IGBT half-bridge module to operate in a pulse width modulation state with opposite phases, generating a fundamental AC current in the AC branch. Based on the target operating conditions, determine the target current value or target power value required for the AC branch; Based on the target current value or target power value, the target equivalent resistance value required for the adjustable resistor unit is obtained; The controller generates a trigger control signal for the thyristor based on the target equivalent resistance value. Based on the trigger control signal, the controller controls the thyristor to work in conjunction with the first IGBT half-bridge module and the second IGBT half-bridge module to adjust the equivalent resistance value of the adjustable resistor unit to the target equivalent resistance value, thereby obtaining AC power that matches the target operating condition.

[0012] This invention can change the equivalent resistance value of the adjustable resistor unit connected to the AC branch by controlling the conduction angle or on / off state of a pair of anti-parallel thyristors, thereby achieving flexible and continuous adjustment of the AC power of the entire test system.

[0013] Optionally, the controller generates a trigger control signal for the thyristor based on the target equivalent resistance value, including: If the current equivalent resistance value of the adjustable resistor unit is greater than the target equivalent resistance value, the firing angle of the thyristor is reduced to generate a trigger control signal for the thyristor. If the current equivalent resistance value of the adjustable resistor unit is less than the target equivalent resistance value, the firing angle of the thyristor is increased to generate the thyristor's start control signal.

[0014] Optionally, based on a trigger control signal, the thyristor is controlled to work in conjunction with the first IGBT half-bridge module and the second IGBT half-bridge module to adjust the equivalent resistance value of the adjustable resistor unit to the target equivalent resistance value, thereby obtaining AC power matching the target operating condition, including: During each half-wave cycle of the fundamental AC current generated in the AC branch, the trigger control signal triggers the corresponding thyristor to conduct after crossing the zero point, infinitely adjusting the equivalent resistance value of the adjustable resistor unit to the target equivalent resistance value, thereby obtaining AC power that matches the target operating condition.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The system of this invention incorporates an adjustable resistor unit intelligently controlled by thyristors in series in the AC branch. This adjustable resistor unit consists of a fixed resistor connected in parallel with a pair of anti-parallel thyristors. The structural changes are minimal, the cost increase is negligible, but the functionality is significantly improved. By controlling the conduction angle and on / off state of the thyristors, and coordinating with the IGBT half-bridge module, the equivalent resistance of the AC branch circuit can be changed steplessly and rapidly, thereby achieving continuous adjustment of AC power. This solves the problem that traditional test systems cannot flexibly represent the dynamic working characteristics of IGBT modules. It is particularly suitable for simulating working conditions with frequent power changes, such as pumped storage, and has the advantages of simple structure, flexible control, and accurate testing. Attached Figure Description

[0016] Figure 1 The diagram shown is a structural schematic of the AC power adjustable IGBT module test system of the present invention in one embodiment; In the diagram: 1. First IGBT half-bridge module; 2. Second IGBT half-bridge module; 3. AC branch; 4. Adjustable resistor unit; 5. Controller; DC power supply; Q1. First IGBT chip; Q2. Second IGBT chip; Q3. Third IGBT chip; Q4. Fourth IGBT chip; D1. First diode; D2. Second diode; D3. Third diode; D4. Fourth diode; C1. First capacitor; C2. Second capacitor; L1. Reactor; T1. Thyristor 1; T2. Thyristor 2; R1. Fixed resistor. Detailed Implementation

[0017] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0018] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0019] Example 1

[0020] like Figure 1 As shown in the figure, this embodiment introduces an AC power adjustable insulated gate bipolar transistor (IGBT) module test system, including a first IGBT half-bridge module 1, a second IGBT half-bridge module 2, and an AC branch 3.

[0021] Both the first IGBT half-bridge module 1 and the second IGBT half-bridge module 2 include IGBT half-bridge sub-modules. The two IGBT half-bridge sub-modules are connected in series and then in parallel with a capacitor. Each IGBT half-bridge module sub-module includes an IGBT chip and a diode connected in anti-parallel with the IGBT chip. The midpoint between the two IGBT half-bridge sub-modules is the AC output terminal of either the first IGBT half-bridge module 1 or the second IGBT half-bridge module 2. In one IGBT half-bridge module, the emitter of the IGBT chip in one IGBT half-bridge sub-module is connected to the collector of the IGBT chip in the other IGBT half-bridge sub-module. The midpoint of the connection is the AC output terminal of that IGBT half-bridge module. The IGBT chip's turn-on and turn-off are controlled by controlling the gate voltage of the IGBT chip.

[0022] In one specific embodiment, the first IGBT half-bridge module 1 includes two first IGBT half-bridge sub-modules. The two first IGBT half-bridge sub-modules are connected in series and then connected in parallel with the first capacitor C1. One of the first IGBT half-bridge sub-modules includes a first IGBT chip Q1 and a first diode D1 connected in anti-parallel to the first IGBT chip Q1. The other first IGBT half-bridge sub-module includes a second IGBT chip Q2 and a second diode D2 connected in anti-parallel to the second IGBT chip Q2. The midpoint between the two first IGBT half-bridge sub-modules is the AC output terminal of the first IGBT half-bridge module 1. The emitter of the first IGBT chip Q1 is connected to the collector of the second IGBT chip Q2, and the midpoint of the connection is the AC output terminal of the first IGBT half-bridge module 1. The second IGBT half-bridge module 2 includes two second IGBT half-bridge sub-modules. The two second IGBT half-bridge sub-modules are connected in series and then in parallel with the second capacitor C2. The second IGBT half-bridge module sub-module includes a third IGBT chip Q3 and a third diode D3 connected in anti-parallel to the third IGBT chip Q3. The other second IGBT half-bridge module sub-module includes a fourth IGBT chip Q4 and a fourth diode D4 connected in anti-parallel to the fourth IGBT chip Q4. The midpoint between the two second IGBT half-bridge sub-modules is the AC output terminal of the second IGBT half-bridge module 2. The emitter of the third IGBT chip Q3 is connected to the collector of the fourth IGBT chip Q4, and the midpoint of the connection is the AC output terminal of the first IGBT half-bridge module 1.

[0023] A DC power supply is connected in parallel across the two ends of the first IGBT half-bridge module 1 or the second IGBT half-bridge module 2. In this embodiment, a DC power supply is connected in parallel across the two ends of the first IGBT half-bridge module. The AC output terminals of the first IGBT half-bridge module 1 and the second IGBT half-bridge module 2 are connected through an AC branch 3.

[0024] AC branch 3 includes a reactor L1 and an adjustable resistor unit 4. The reactor L1 is used to limit the rate of change of current and filter it. Its inductance value can be selected according to the rated value of the test current and the frequency, for example, a smoothing reactor of 2mH can be selected.

[0025] The adjustable resistor unit 4 includes a fixed resistor R1 and a pair of anti-parallel thyristors connected in parallel with the fixed resistor R1. These anti-parallel thyristors are designated as T1 and T2. The fixed resistor R1 serves as a reference resistor, and its resistance and power rating need to be selected based on the system's maximum test current and the required adjustment range. For example, to achieve continuous adjustment of the AC current within 50% to 100% of its rated value, a water-cooled non-inductive resistor with a resistance of 0.5Ω and a power rating of 5kW can be selected.

[0026] One end of reactor L1 is connected to the AC output terminal of the first IGBT half-bridge module 1 or the AC output terminal of the second IGBT half-bridge module 2, and the other end is connected to one end of a pair of anti-parallel thyristors in the adjustable resistor unit 4. The other end of the pair of anti-parallel thyristors is connected to the AC output terminal of the second IGBT half-bridge module 2 or the AC output terminal of the first IGBT half-bridge module 1.

[0027] This embodiment can change the equivalent resistance value of the adjustable resistor unit connected to the AC branch by controlling the conduction angle or on / off state of a pair of anti-parallel thyristors, thereby achieving flexible and continuous adjustment of the AC power of the entire test system.

[0028] Example 2

[0029] Based on the system in Example 1, this example introduces a test method for an AC power adjustable IGBT module, including the following steps: Step 1: Control the thyristors T1 and T2 in the adjustable resistor unit 4 to be in the off state, so that the full resistance value of the fixed resistor R1 is connected in series with the AC branch 3. At this time, the equivalent resistance of the adjustable resistor unit is the maximum, which is the fixed resistor R1.

[0030] Step 2: Controller 5 generates two drive signals, one of which is two pulse width modulation (PWM) drive signals with opposite phases, driving the upper and lower arms of the first IGBT half-bridge module 1 and the second IGBT half-bridge module 2 respectively, so that the first IGBT half-bridge module 1 and the second IGBT half-bridge module 2 operate in an inverter / rectifier push-back state, thereby generating an AC current I with a fundamental frequency of f (e.g., 50Hz) in AC branch 3. ac The other driving signal is the thyristor trigger control signal, which monitors the current signal of AC branch 3 (which can be obtained through a current sensor). Based on this current signal, the zero-crossing point of the current can be accurately calculated so as to control the trigger control signal to trigger the corresponding thyristor to conduct after the zero-crossing point. The thyristor trigger control signal is generated according to the target operating condition.

[0031] Step 3: Based on the target operating condition to be simulated, determine the target current or target power value required for AC branch 3. Based on the target current or power value, calculate the target equivalent resistance value required for adjustable resistor unit 4. When it is necessary to adjust the system power, the user sets a target current value I to the controller 5 through the host computer. target The controller 5 calculates the target equivalent resistance value R of the circuit to be connected based on the system parameters and the target current. target .

[0032] Step 4: The controller generates a trigger control signal for the thyristor based on the target equivalent resistance value. If the current equivalent resistance value of the adjustable resistor unit 4 is greater than the target equivalent resistance value, the loop resistance needs to be increased (current reduced) to decrease the thyristor's firing angle (i.e., delay the issuance time of the trigger pulse) and generate the thyristor's trigger control signal. The smaller the firing angle, the longer the thyristor conducts, the longer R1 is short-circuited, and the smaller the equivalent resistance value.

[0033] If the current equivalent resistance value of the adjustable resistor unit 4 is less than the target equivalent resistance value, then it is necessary to reduce the loop resistance (increase the current), increase the firing angle of the thyristor (i.e., issue the trigger pulse earlier), and generate the trigger control signal for the thyristor. The larger the firing angle, the shorter the conduction time of the thyristor in each half-wave cycle, and the shorter the short-circuit time of the fixed resistor R1. Therefore, the equivalent resistance value presented by the adjustable resistor unit 4 is closer to the resistance value of R1 itself.

[0034] Step 5: According to the trigger control signal, control the thyristor to work in coordination with the first IGBT half-bridge module 1 and the second IGBT half-bridge module 2. In each half-wave cycle of the fundamental AC current generated in the AC branch 3, the trigger control signal triggers the corresponding thyristor to conduct at a specific electrical angle after the positive zero crossing point, thereby short-circuiting the fixed resistor R1 and steplessly adjusting the equivalent resistance value of the adjustable resistor unit 4 to the target equivalent resistance value, so as to obtain AC power that matches the target operating condition. In one specific embodiment, when the alternating current I... ac During the positive half-cycle, controller 5 sends a trigger pulse to thyristor T1 after a delay of the trigger angle α following the current zero crossing; during the AC current I... ac During the negative half-cycle, controller 5 also delays the trigger angle α after the current crosses zero and sends a trigger pulse to thyristor T2. By continuously changing the trigger angle α (usually in the range of 5° to 175°), the equivalent resistance value of adjustable resistor unit 4 can be continuously and steplessly adjusted between close to 0 and the resistance value of fixed resistor R1 to obtain AC power that matches the target operating condition.

[0035] In this embodiment, the process of the pumped storage unit's power steadily increasing from 30% to 100% during startup is simulated. The controller 5 dynamically calculates and adjusts the trigger angle α based on the real-time collected current value of the AC branch 3 and the target curve of the pumped storage unit during startup, so that the equivalent resistance value of the adjustable resistor unit 4 follows the change of the target curve, thereby accurately controlling the current of the AC branch 3 and achieving equivalence to the target operating condition.

[0036] Throughout the dynamic process, parameters such as junction temperature, voltage, and current of the IGBT module are recorded to assess the electrothermal stress of the IGBT half-bridge module under the target operating condition.

[0037] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An AC power adjustable IGBT module test system, characterized by, The first IGBT half-bridge module, the second IGBT half-bridge module and the AC branch are included. The AC output terminals of the first IGBT half-bridge module and the second IGBT half-bridge module are connected through the AC branch. The AC branch includes an adjustable resistance unit, the adjustable resistance unit includes a fixed resistance and a pair of anti-parallel thyristors connected in parallel with the fixed resistance, the two ends of the pair of anti-parallel thyristors are respectively connected to the AC output terminals of the first IGBT half-bridge module and the second IGBT half-bridge module, and the gates of the two thyristors are connected to the output terminal of the controller.

2. The AC power adjustable IGBT module test system of claim 1, wherein, The first IGBT half-bridge module or the second IGBT half-bridge module is connected in parallel with a DC power supply.

3. The AC power adjustable IGBT module test system of claim 1, wherein, The first IGBT half-bridge module and the second IGBT half-bridge module each include an IGBT half-bridge sub-module, and the two IGBT half-bridge sub-modules are connected in series and connected in parallel with a capacitor. The midpoint of the two IGBT half-bridge sub-modules is the AC output terminal of the first IGBT half-bridge module or the second IGBT half-bridge module.

4. The AC power adjustable IGBT module test system of claim 3, wherein, The IGBT half-bridge sub-module includes an IGBT chip and a diode connected in anti-parallel with the IGBT chip. In one IGBT half-bridge module, the emitter of the IGBT chip in one IGBT half-bridge sub-module is connected to the collector of the IGBT chip in another IGBT half-bridge sub-module, and the connection midpoint is the AC output terminal of the IGBT half-bridge module.

5. The AC power adjustable IGBT module test system of claim 1, wherein, The AC branch further includes an electric reactor. One end of the electric reactor is connected to the AC output terminal of the first IGBT half-bridge module or the AC output terminal of the second IGBT half-bridge module, and the other end is connected in series with the adjustable resistance unit. The equivalent resistance value of the adjustable resistance unit is continuously adjustable between the resistance value of the fixed resistance and zero resistance value.

6. A test method of an AC power adjustable IGBT module test system, characterized by, The system of any one of claims 1-5 is used for testing, and the method includes: The controller controls the first IGBT half-bridge module and the second IGBT half-bridge module to work in a pulse width modulation state with opposite phases to generate a fundamental AC current in the AC branch; According to a target working condition, a target current value or a target power value required by the AC branch is determined; According to the target current value or the target power value, a target equivalent resistance value required by the adjustable resistance unit is obtained; The controller generates a trigger control signal of the thyristor according to the target equivalent resistance value, and controls the thyristor to work cooperatively with the first IGBT half-bridge module and the second IGBT half-bridge module according to the trigger control signal, so as to adjust the equivalent resistance value of the adjustable resistance unit to the target equivalent resistance value, and obtain an AC power matching the target working condition.

7. The test method of the AC power adjustable IGBT module test system according to claim 6, characterized in that, The controller generates a trigger control signal of the thyristor according to the target equivalent resistance value, including: If the current equivalent resistance value of the adjustable resistance unit is greater than the target equivalent resistance value, the trigger angle of the thyristor is reduced to generate the trigger control signal of the thyristor; If the current equivalent resistance value of the adjustable resistance unit is less than the target equivalent resistance value, the trigger angle of the thyristor is increased to generate the trigger control signal of the thyristor.

8. The test method of the AC power adjustable IGBT module test system according to claim 6, characterized in that, According to the trigger control signal, the thyristor is controlled to work cooperatively with the first IGBT half-bridge module and the second IGBT half-bridge module, the equivalent resistance value of the adjustable resistance unit is adjusted to a target equivalent resistance value, and the AC power matched with the target working condition is obtained, comprising: In each half-wave period of the fundamental AC current generated in the AC branch, the trigger control signal triggers the corresponding thyristor to conduct after the zero-crossing point, the equivalent resistance value of the adjustable resistance unit is continuously adjusted to the target equivalent resistance value, and the AC power matched with the target working condition is obtained.

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