CN106885986B - Dynamic parameter extraction device and method for power converter switch - Google Patents

Abstract

The invention discloses a power converter switch dynamic parameter extraction device which comprises a hardware test platform, a data acquisition module, a controller, an upper computer and a data post-processing module. The invention also discloses a method for extracting the dynamic parameters of the power converter switch, which is used for testing by using the device for extracting the dynamic parameters of the power converter switch. The device has high degree of automation and easy operation, can rapidly and accurately extract the electric parameters of the power device switching transient process, is used for guiding the reliability design of the power converter, and is used for analyzing the change rule of related parameters in the power device decay process so as to evaluate the health condition of the power converter.

Description

A power converter switch dynamic parameter extraction device and extraction method

technical field

The invention relates to a power converter switch dynamic parameter extraction device and an extraction method, belonging to the application field of power electronics in power systems.

Background technique

In the new energy conversion system, the key part that affects the reliability is the power converter device, and the power device is not only the core component of the device, but also one of the most vulnerable components. Therefore, reliability-oriented power converter design and operation and maintenance are of great significance to ensure the safe and stable operation of new energy power generation systems.

During the life course of a semiconductor device, its reliability is affected by various internal and external factors, and there are multi-physics couplings such as electricity, heat, and mechanics. The failure may be either electromagnetic transient failure or time-dependent thermal fatigue damage. Aging failure due to accumulation. Reliability-oriented converter design consists in reducing the probability of both failure modes.

The electromagnetic transient failure is mainly caused by the internal high temperature and electrical stress of the device. The electrothermal stress is related to the design of the commutation circuit, drive circuit and radiator. Turn-on reverse recovery current, rate of change of voltage and current, power device junction temperature and heat sink temperature, etc.) are in the safe and stable area of the system. These electrothermal parameters can be obtained through measurement and data post-processing.

The aging failure of power devices depends on time. During the decay process, relevant electrothermal parameters (such as saturation voltage drop vce, threshold voltage vgeth and thermal impedance Zth, etc.) will change accordingly. In order to reduce the aging failure caused by power converters Unscheduled maintenance costs and downtime losses, etc., it is necessary to deeply study the change law of relevant electrical parameters during the aging process of IGBT devices, and test and analyze the relevant electrical parameters of the power converter during the operation process.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art, to provide a power converter switch dynamic parameter extraction device, which has a high degree of automation and is easy to operate, and can quickly and accurately extract the electrical parameters of the power device switch transient process. It is used to guide the reliability design of power converters, and is used to analyze the change law of related parameters in the process of power device degradation and then evaluate the health status of power converters.

Another object of the present invention is to provide a method for extracting dynamic parameters of switches of a power converter, using the above-mentioned device for extracting dynamic parameters of switches of a power converter to extract dynamic parameters of switches.

The technical solution for realizing the above purpose is: a device for extracting dynamic parameters of power converter switches, including a hardware test platform, a data acquisition module, a controller, a host computer and a data post-processing module;

The hardware testing platform includes a transformer, a rectifier, a capacitor, a charging resistor, a hardware testing platform, an energy dissipation resistor, a laminated busbar, a power device, and a heating plate; the transformer, the rectifier, the charging resistor, and a relay are serially connected as the The power input of the capacitor, the capacitor and the power device are respectively installed on the laminated busbar, and the energy leakage resistor is connected in parallel with the capacitor;

The power device is fixed on the heating plate through thermal conductive silicone grease, and the heating plate is connected with a temperature controller;

The data acquisition module includes a data collector and an oscilloscope, the data collector collects current and voltage data, and uploads the current and voltage data to the oscilloscope and the host computer;

The controller is configured to accept instructions from the host computer, and issue a trigger pulse instruction and a blocking instruction to the power device through an optical fiber;

The host computer is used to control the instruction layer, and transmits the test conditions to the controller through the communication interface; transmits the sampling conditions to the data collector and the oscilloscope through the communication interface;

The data post-processing module completes the post-processing operation of the current and voltage data, and extracts switching dynamic parameters of the power device, and the switching dynamic parameters include switching time, turn-on current overshoot, turn-off voltage and switching loss.

The above-mentioned power converter switch dynamic parameter extraction device, wherein, the controller adopts a DSP controller; the upper computer adopts a LabVIEW upper computer; the data post-processing module adopts a data post-processing GUI (Graphical User Interface, referred to as GUI, Also known as Graphical User Interface).

In the above-mentioned device for extracting dynamic parameters of power converter switches, the alternating current is sequentially boosted by the transformer, uncontrollably rectified by the rectifier, connected in series with the charging resistor and the relay, and used as the power input of the capacitor, and the capacitor and power Devices are respectively installed on the laminated busbars, and the energy leakage resistor is connected in parallel with the capacitor to discharge the energy of the capacitor; the heating plate is controlled by the temperature controller to maintain it at a set temperature.

In the above device for extracting dynamic parameters of switches of power converters, the data collector includes a current probe and a current probe, wherein:

The current probe collects collector current data, and uploads the collector current data to the oscilloscope and the host computer;

The voltage probe collects collector-emitter voltage data, diode voltage data, gate drive voltage data and auxiliary voltage data, and uploads all collected voltage data to the oscilloscope and the host computer.

A method for extracting a dynamic parameter of a switch of a power converter, using the above-mentioned device for extracting a dynamic parameter of a switch of a power converter to extract a dynamic parameter of a switch, comprising the following steps:

S1, install the test module on the laminated busbar, clamp the test probe on the terminal to be tested, check the test circuit, and ensure that the control line and power line are isolated from the heating plate;

S2, check whether there is a short-circuit point in the connection of the hardware test platform, and then check whether the communication line between the DSP controller and the computer, the drive power supply line, and the computer and the oscilloscope are correctly connected;

S3, open the LabVIEW upper computer in the computer, then close the auxiliary power switch of the hardware test platform, and then close the oscilloscope, controller and drive power switch;

S4, adjust the temperature controller to the temperature point you want to test, and close the temperature power switch of the temperature controller;

S5, run the main interface of LabVIEW, and then click to start the test after inputting the test information to enter the oscilloscope and parameter setting interface;

S6, set the test temperature, test voltage and test current in the test condition input column, then set the sampling condition in the oscilloscope setting column;

S7, after closing the main power air switch, the double pulse test is automatically completed, and the oscilloscope data is automatically transmitted to the computer;

S8, running the data post-processing GUI interface of MATLAB, automatically importing the collected current and voltage data and calculating the switching dynamic parameters of the power device.

The power converter switch dynamic parameter extraction device and extraction method of the present invention can measure the dynamic parameters of the power device system switching process, extract electrical parameters that can reflect the health status of the power device, and then evaluate the reliability of the system to solve existing engineering problems. The technology does not extract enough parameters of power devices to reflect the health status of their operation, so as to ensure the reliable and stable operation of the entire power converter system, and can also guide the reliability design of the converter.

Compared with the prior art, the power converter switch dynamic parameter extraction device and extraction method of the present invention have the following beneficial effects:

1. The extraction device provided by the present invention has a high degree of automation, is simple and easy to operate, and has a friendly interface. The power device is installed on the laminated busbar terminal, and the switching dynamic parameters of multiple power devices can be measured;

2. The extraction device provided by the present invention can further extract electrical parameters that can reflect the health status of power devices on the basis of switch dynamic parameter measurement, and can be used for reliability assessment;

3. The extraction device provided by the present invention extracts the parasitic parameters of the commutation circuit of the converter in the integral form of the variable of the electric parameter in a certain stage of the switching process, and has higher accuracy than the prior art;

4. The extraction device provided by the present invention can simply and easily extract dynamic parameters related to temperature, and can be used for junction temperature evaluation of power devices.

Description of drawings

Fig. 1 is the structural block diagram of the power converter switch dynamic parameter extraction device of the present invention;

Fig. 2a is a test circuit diagram of the hardware test platform of the power converter switch dynamic parameter extraction device;

Fig. 2b is a test timing diagram of the hardware test platform of the power converter switch dynamic parameter extraction device;

Figure 3a is the relationship curve between IGBT turn-off loss, current and temperature;

Figure 3b is the relationship curve between IGBT turn-on loss, current and temperature;

Figure 4a is the relationship curve between IGBT turn-off time, current and temperature;

Figure 4b is the relationship curve between IGBT turn-on time, current and temperature.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, its specific implementation will be described in detail below in conjunction with the accompanying drawings:

Please refer to FIG. 1 , an embodiment of the present invention, a power converter switch dynamic parameter extraction device, includes a hardware test platform 1 , a data acquisition module 2 , a controller 3 , a host computer 4 and a data post-processing module 5 . The controller 3 uses a DSP controller; the upper computer 4 uses a LabVIEW upper computer; the data post-processing module 5 uses a data post-processing GUI interface.

The hardware test platform 1 includes a transformer, a rectifier, a capacitor, a charging resistor, a hardware testing platform, an energy leakage resistor, a laminated busbar, a power device, and a heating plate; the transformer, the rectifier, the charging resistor, and a relay are sequentially connected in series as the power of the capacitor. The input, capacitors and power devices are respectively installed on the laminated busbar, and the energy leakage resistor is connected in parallel with the capacitor; the power device is fixed on the heating plate through thermal conductive silicone grease, and the heating plate is connected with a temperature controller.

The data acquisition module 2 includes a data collector and an oscilloscope, and the data collector collects current and voltage data, and uploads the current and voltage data to the oscilloscope and the LabVIEW host computer 4;

The controller 3 is used to accept the instructions from the LabVIEW host computer 4, and sends trigger pulse instructions and blocking instructions to the power devices through the optical fiber; the LabVIEW host computer 4 is used to control the instruction layer, and transmit the test conditions to the controller via the communication interface. The sampling condition is transmitted to the data collector and the oscilloscope through the communication interface; the data post-processing module 5 completes the post-processing operation of the current and voltage data, and extracts the switching dynamic parameters of the power device, including switching time, turn-on current overshoot, turn-off voltage and switching losses.

The alternating current is boosted by the transformer, uncontrollably rectified by the rectifier, connected in series with the charging resistor and the relay, and used as the power input of the capacitor. Energy; the heating plate is controlled by a temperature controller to maintain the set temperature.

The data collector includes a current probe and a current probe, the current probe collects collector current data _ic , and uploads the collector current data _ic to the oscilloscope and the host computer; the voltage probe collects collector-emitter voltage data V _ce , diode voltage data V _D , gate drive voltage data V _ge and auxiliary voltage data V _eE , and upload all collected voltage data to the oscilloscope and the host computer.

Please refer to Figure 2a and Figure 2b, hardware test platform 1, using a typical double-pulse test circuit to test the switching dynamic waveform of power devices, the test objects are the lower-side IGBT and the upper-side diode, including steps:

(1) 0～t ₁ : at time t=0, the tested IGBT is turned on, the bus bar charges the inductor L through the IGBT, and the inductor current I _L rises linearly until the inductor current _IL rises to the specified test value I ₁ at the time t ₁ ;

(2) t ₁ ~ t ₂ : at time t ₁ , the IGBT under test is turned off _, and the waveform of the off-off parameters such as IGBT turn-off voltage _and current can be captured. open again;

(3) t ₂ ~ t ₃ : At time t ₂ , the IGBT is turned on again, and the waveform of the turn-on parameters such as the turn-on voltage and current of the IGBT can be captured. When the load inductance is large enough, it can be considered that the current value I ₂ that the IGBT is turned on at this time is equal to the current value I ₁ that is turned off at the time t ₁ ; at this stage, the load current _IL continues to rise until the time t ₃ , when the current is I ₃ ;

(4) After _t3 : At time _t3 , the IGBT is turned off again, and the inductor current I _L continues to flow through the upper diode D until the current drops to zero, and the single double pulse test cycle ends.

The switching sequence of the upper and lower bridge arm power devices involved in the above steps (1)-(4) is issued by the DSP digital controller, and the control instruction comes from the host computer;

The collector current _ic , collector-emitter voltage V _ce , diode voltage V _D and gate drive voltage V _ge of the upper and lower bridge arm power devices involved in the above steps (1)-(4) are determined by the voltage current The probe is acquired and automatically uploaded to the oscilloscope and the host computer;

After the switch dynamic electrical parameter data involved in the above steps (1)-(4) is uploaded to the host computer, the data post-processing needs to be performed through the GUI interface operation. The extraction includes switching time, turn-on current overshoot, turn-off voltage spike, power device Switching dynamic parameters such as switching loss, saturation voltage drop under high current, and switching Miller plateau voltage.

The IGBT device to be tested is the FF400R33KF2C module of Infineon Company, and the relevant parameters of the hardware test platform in the embodiment are shown in Table 1:

parameter value DC bus voltage 2000V DC side capacitance 15000μF Double pulse experimental current ≤3600A filter inductor 320μH Test temperature T _j range Room temperature～125℃

Table 1

The test process is carried out in strict accordance with the following test procedures.

A method for extracting dynamic parameters of a power converter switch, comprising the following steps:

S1, install the test module on the laminated busbar, clamp the test probe on the terminal to be tested, check the test circuit, and ensure that the control line and power line are isolated from the heating plate;

S2, check whether there is a short-circuit point in the connection of the hardware test platform, and then check whether the communication line between the controller and the computer, the drive power supply line, and the computer and the oscilloscope are correctly connected;

S3, turn on the upper computer in the computer, then close the main switch of the auxiliary power supply of the hardware test platform, and close the oscilloscope, controller and drive power switch in turn;

S4, adjust the temperature controller to the temperature point you want to test, and close the temperature power switch of the temperature controller;

S5, run the main interface of LabVIEW, and then click to start the test after inputting the test information to enter the oscilloscope and parameter setting interface;

S6, set test temperature, test voltage and test current, etc. in the test condition input column, then set the sampling conditions in the oscilloscope setting column;

S7, after closing the main power air switch, the double pulse test is automatically completed, and the oscilloscope data is automatically transmitted to the computer;

S8, running the data post-processing module of MATLAB, automatically importing the collected current and voltage data and calculating the switching dynamic parameters of the power device.

Please refer to Figure 3a, Figure 3b, Figure 4a and Figure 4b, which are the relationship curves of IGBT switching loss, switching time, current and temperature respectively. It can be seen from the change trend that as the load current level increases, the switching loss of the device under test continues to increase. increase, and the switching loss of the device under test has a positive temperature coefficient, the higher the junction temperature of the device, the greater the loss; at different junction temperatures, the turn-on time of the device has a consistent trend with the change of the load current level, and the larger the load current, the greater the loss. The longer the turn-on time, and the turn-on time of the device under test has a positive temperature coefficient. This device can also extract other temperature-related switch dynamic parameters, but due to space limitations, not all of them are listed.

In summary, the power converter switch dynamic parameter extraction device and extraction method of the present invention have a high degree of automation and are easy to operate, and can quickly and accurately extract the electrical parameters of the switching transient process of the power device to guide the power converter. The reliability design of the converter is used to analyze the change law of related parameters in the process of power device degradation and then evaluate the health status of the power converter.

Those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present invention, rather than as a limitation to the present invention, as long as within the scope of the spirit of the present invention, the above-described embodiments Changes and modifications will fall within the scope of the claims of the present invention.

Claims (5)

1. A device for extracting dynamic parameters of a power converter switch, characterized in that it comprises a hardware test platform, a data acquisition module, a controller, an upper computer and a data post-processing module; The hardware test platform includes a transformer, a rectifier, a capacitor, a charging resistor, a relay, a discharge resistor, a laminated busbar, a power device, and a heating plate; Power input, the capacitor and the power device are respectively installed on the laminated busbar, and the energy leakage resistor is connected in parallel with the capacitor; The power device is fixed on the heating plate through thermal conductive silicone grease, and the heating plate is connected with a temperature controller; The data acquisition module includes a data collector and an oscilloscope, the data collector collects current and voltage data, and uploads the current and voltage data to the oscilloscope and the host computer; The controller is configured to accept instructions from the host computer, and issue a trigger pulse instruction and a blocking instruction to the power device through an optical fiber; The host computer is used to control the instruction layer, and transmits the test conditions to the controller through the communication interface; transmits the sampling conditions to the data collector and the oscilloscope through the communication interface; The data post-processing module completes the post-processing operation of the current and voltage data, and extracts switching dynamic parameters of the power device, and the switching dynamic parameters include switching time, turn-on current overshoot, turn-off voltage and switching loss. 2. power converter switch dynamic parameter extraction device according to claim 1, is characterized in that, described controller adopts DSP controller; Described upper computer adopts LabVIEW upper computer; Described data post-processing module adopts data post-processing Handles the GUI interface. 3. The device for extracting dynamic parameters of a power converter switch according to claim 1, wherein the alternating current is sequentially boosted by the transformer, uncontrollably rectified by the rectifier, and connected in series with the charging resistor and the relay as the capacitor The power input of the capacitor and the power device are respectively installed on the laminated busbar, and the leakage resistor is connected in parallel with the capacitor to release the energy of the capacitor; the heating plate is controlled by the temperature controller It is maintained at a set temperature. 4. The power converter switch dynamic parameter extraction device according to claim 1, wherein the data collector includes a current probe and a current probe, wherein: The current probe collects collector current data, and uploads the collector current data to the oscilloscope and the host computer; The voltage probe collects collector-emitter voltage data, diode voltage data, gate drive voltage data and auxiliary voltage data, and uploads all collected voltage data to the oscilloscope and the host computer. 5. A method for extracting dynamic parameters of a switch of a power converter, utilizing the device for extracting dynamic parameters of a switch of a power converter according to claim 2 to extract a dynamic parameter of a switch, characterized in that it comprises the following steps: S1, install the test module on the laminated busbar, clamp the test probe on the terminal to be tested, check the test circuit, and ensure that the control line and power line are isolated from the heating plate; S2, check whether there is a short-circuit point in the connection of the hardware test platform, and then check whether the communication line between the DSP controller and the computer, the drive power supply line, and the computer and the oscilloscope are correctly connected; S3, open the LabVIEW upper computer in the computer, then close the auxiliary power switch of the hardware test platform, and then close the oscilloscope, controller and drive power switch; S4, adjust the temperature controller to the temperature point you want to test, and close the temperature power switch of the temperature controller; S5, run the main interface of LabVIEW, and then click to start the test after inputting the test information to enter the oscilloscope and parameter setting interface; S6, set the test temperature, test voltage and test current in the test condition input column, then set the sampling condition in the oscilloscope setting column; S7, after closing the main power air switch, the double pulse test is automatically completed, and the oscilloscope data is automatically transmitted to the computer; S8, running the data post-processing GUI interface of MATLAB, automatically importing the collected current and voltage data and calculating the switching dynamic parameters of the power device.

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