RU2752780C1 - Software and hardware solutions for managing igbt modules based on driver on microcontroller - Google Patents

Abstract

FIELD: power modules.

SUBSTANCE: invention relates to power modules based on bipolar transistors with an isolated gate. The transistor buffer creates the necessary current iG to recharge the gate capacity G. The additional circuit measures the voltage VEe, proportional to the current iC, released on the inductance LE and the resistance RE of the emitter output of the transistor. This VEe voltage is involved in the measurement of the collector current and in the formation of an error signal: a large emitter current. Also, the VEe is fed to the operational amplifier (OA), closing the current feedback. This is a safe current mode circuit: the more iC current, the less is the control signal at the gate. The second circuit of the safe mode is by voltage. The collector voltage Uc is fed to the OA through the differential circuit Cv, closing the feedback on the change in the voltage Uc. A rapid increase in voltage (usually when switched off) causes an increase in the gate voltage, tightening the front of the collector voltage growth Uc, while the piecewise linear approximation of the transistor model describes the saturation voltage as: Usat=Vo+(Ro+Temperature/K)*Ic, and the crystal temperature is calculated according to the dependence: Temperature = ((Usat-Vo)/Ic-Ro)*K+To.

EFFECT: expanding the arsenal of means for registering data on the operating mode of IGBT modules for generating signals for correcting the operating mode through a piecewise linear approximation of the transistor model when calculating the temperature, while the driver circuit is implemented in a controller that creates a reference Vref voltage for an operational amplifier that creates a control voltage at the gate of the transistor G.

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Description

FIELD OF TECHNOLOGY

The invention relates to power modules based on insulated gate bipolar transistors (IGBT) - transistors that are widely used in converter technology, displacing bipolar power devices.

LEVEL OF TECHNOLOGY

Studying the experience of existing solutions in the field of technology in the development of frequency drives from successful manufacturers of semiconductor devices in the field of frequency converters (FCs) such companies as Alstom, ABB, Schneider Electric, CT-Concept Technologie AG and Power Integrations and other major manufacturers of drivers for IGBT modules revealed a number of disadvantages of the algorithms for controlling these modules.

Also, in the course of experiments on the development of an algorithm for controlling the formation of pulse-width modulation (PWM) signals, various characteristics were revealed for identical modules from different manufacturers. The experiments were carried out both on IGBT modules from European manufacturers and on modules purchased in the Asian part of the world.

Based on the results of the experiments, it was determined that to implement the control algorithm for a set of IGBT modules, there is not enough data received from the driver about the state of these same IGBT modules when the inverter is implemented on the hardware available on the market.

DISCLOSURE OF THE INVENTION

The technical result of the invention consists in expanding the arsenal of means for recording data on the operating mode of the IGBT modules for generating signals for correcting the operating mode through piecewise linear approximation of the transistor model when calculating the temperature.

It was decided to implement a project to create a custom IGBT module driver based on a controller, for example, based on the ARM Cortex-M4 architecture.

In one implementation, the driver is based on an ARM Cortex-M4 STM32F405 manufactured by ST and op amps manufactured by Analog Devices.

In accordance with the preferred embodiment, the block diagram of the driver for recording data on the operation mode of IGBT modules and generating control signals is implemented in a controller that generates a reference voltage Vref for an operational amplifier that creates a control voltage across the gate of transistor G. Transistor buffer creates the necessary current iG to recharge the gate capacitance G. The additional circuit measures the voltage VEe, which is proportional to the current iC, which emits across the inductor LE and the resistance RE of the emitter terminal of the transistor. This voltage VEe participates in the measurement of the collector current and in the formation of an error signal - a large emitter current. The VEe is also fed to an operational amplifier (op-amp), completing the current feedback. This is a current-safe circuit: more iC current means less gate drive signal. The second circuit of the safe mode is by voltage. The collector voltage Uc through the differential circuit Cv is fed to the op-amp, closing the feedback on the change in voltage Uc. A rapid rise in voltage (usually at turn-off) causes an increase in the gate voltage, delaying the rise in the collector voltage Uc.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows the diagram of the driver.

FIG. 2 shows a diagram for generating error signals.

FIG. 3 dependences of the saturation voltage of the collector on the current at different temperatures of the crystal.

CARRYING OUT THE INVENTION

FIG. 1 shows a driver system, in accordance with which a driver for recording data on the operating mode of IGBT modules for generating signals for correcting the operating mode, while the driver circuit is implemented in a controller that creates a reference voltage Vref 101 for an operational amplifier that creates a control voltage at the gate of transistor G 102 The transistor buffer generates the necessary current iG 103 to recharge the gate capacitance G 102. The additional circuit measures the voltage VEe 104, which is proportional to the current iC 105, emitting across the inductor LE 106 and the resistance RE of the emitter terminal of the transistor. This voltage VEe 104 participates in the measurement of the collector current and in the formation of an error signal - a large emitter current. Also, VEe 104 is fed to the operational amplifier (OPA) 107, closing the current feedback. This is a current-safe circuit: more iC 105 current means less gate drive signal. The second circuit of the safe mode is by voltage. The collector voltage Uc through the differential circuit Cv 108 is supplied to the op-amp 107, closing the feedback on the change in voltage Uc. A rapid rise in voltage (usually at turn-off) causes an increase in the gate voltage, delaying the rise in the collector voltage Uc.

Referring to FIG. 2, the controller receives the signals of the emitter current ic and the collector saturation voltage Vce, on to digitize and calculate the crystal temperature. Also, voltage comparators generate error signals when current> ic, max, voltage> Vce, max is exceeded.

A piecewise linear approximation of the transistor model describes the saturation voltage: Usat = Vo + (Ro + Temperature / K) * Ic.

Referring to FIG. 3, the crystal temperature is determined according to the following relationship: Temperature = ((Usat-Vo) / Ic-Ro) * K + To, where Usat is the measured saturation voltage 0.8-8 V, To is 25C, Vo is the initial saturation voltage 0, 8-1.2 V Ic - measured emitter, collector current 0-800 A, Ro - collector-emitter resistance for a specific IGBT module, K - coefficient for a specific IGBT module.

The block diagram of the driver disclosed above allows you to realize the following advantages:

1. Isolate power supplies.

2. To turn on and off the transistor according to the state of the control signal.

3. Create a safe operating mode for the transistor: current limiting, limiting the collector voltage rise, limiting the collector voltage.

4. Form a signal of the status, the state of the driver.

5. Measure the parameters of the transistor and calculate the temperature of the crystal of the transistor.

6. Receive and transmit transistor parameter data and driver error codes.

Additional advantages of the implemented driver are to provide protective functions such as:

1. Low supply voltage - when +18 V voltage drops below 15 V.

2. High saturation voltage of the transistor, possibly with high collector current.

3. Large emitter current.

4. High temperature of the crystal of the transistor.

Based on the above hardware measurements and their software processing, the execution of the driver on the controller additionally makes it possible to predict the state of the inverter as a whole.

In one of the embodiments, the controller calculates the crystal temperature according to the technical characteristics of the dependence of the crystal temperature of the IGBT module on its operating mode, which are known from the documentation. Calculation is possible only when the transistor is turned on and the PWM time is at least 20 μs. Based on the received data, the IGBT driver microcontroller calculates the expected behavior of both the IGBT module and the individual transistor in the module. In case of discrepancy between the real model and the mathematical one, the controller takes measures to stabilize the operating state of the set of IGBT modules (inverter).

Claims (1)

A driver system for recording data on the operating mode of IGBT modules and generating control signals, characterized in that the driver is made in a controller that creates a reference voltage Vref for an operational amplifier that creates a control voltage at the gate of the transistor G, while: the transistor buffer creates the required current iG to recharge the gate capacitance G; the additional circuit measures the voltage VEe, proportional to the current iC, released at the inductance LE and the resistance RE of the emitter terminal of the transistor; voltage VEe participates in the measurement of the collector current and in the formation of an error signal at a large emitter current; VEe is fed to an operational amplifier (op-amp), completing the current feedback; in this case, the current safe circuit generates a correcting control signal under the following conditions: the current safe circuit when the current iC rises, the control signal at the gate decreases; the voltage safety circuit switches on the supply of the collector voltage Uc through the differential circuit Cv to the op-amp, closing the feedback on the change in the voltage Uc; the circuit of the safe mode by increasing the voltage causes an increase in the gate voltage, delaying the rise of the collector voltage Uc, in which the piecewise linear approximation of the transistor model describes the saturation voltage as: Usat = Vo + (Ro + Temperature / K) * Ic, and the crystal temperature is calculated in in accordance with the dependence: Temperature = ((Usat-Vo) / Ic-Ro) * K + To, where Usat - measured saturation voltage 0.8 - 8 V, To - 25C, Vo - initial saturation voltage 0.8-1, 2, Ic - measured emitter, collector current 0-800 A, Ro - collector-emitter resistance for a specific IGBT module, K - coefficient for a specific IGBT module.

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