CN201146457Y - Dedicated thick film circuit for drive control of IPM power switching devices - Google Patents

Abstract

The utility model discloses a special thick-film circuit for drive control of an IPM power switch device, comprising: a first photoelectric coupler, a second photoelectric coupler, signal processing, logic control and drive protection unit, a power amplification unit, a drive Control unit, fault feedback unit, short circuit detection unit, current sampling unit, temperature detection unit; the amplified control signal enters the drive control unit to drive the IPM power switching device; the fault signal passes through the second photocoupler after being fed back by the fault feedback unit Output after isolation; the short-circuit detection unit detects the short-circuit fault of the IPM power switching device; the current sampling unit samples the operating current of the IPM power switching device through an external current sensor; the temperature detection unit detects the operating temperature of the IPM power switching device through an external temperature sensor. The drive and protection of the power switching device are realized by adopting the special thick film circuit of the utility model.

Description

Dedicated thick film circuit for drive control of IPM power switching devices

technical field

The utility model relates to a special thick film circuit for IPM (Intelligent Power Module, intelligent power module) drive control, in particular to a kind of drive for the power switch device IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) inside the IPM A thick-film circuit that provides a processing interface for protection and external control signals.

Background technique

In recent years, power electronics technology is developing rapidly in the direction of large capacity, modularization, intelligence and low cost, in order to increase the power density of the device, reduce noise, reduce energy consumption and raw material consumption, simplify circuit design and improve system performance. reliability. IPM is a new type of power electronic device developed under this trend. The device generally takes the insulated gate bipolar transistor IGBT as the basic power switching device.

The biggest feature of IPM is the integration of data interface, power conversion, drive and protection circuits. IPM is widely used in industrial and consumer fields, especially in the field of variable frequency speed regulation of motors, such as: frequency conversion air conditioners, frequency conversion refrigerators, frequency conversion speed regulators and inverter power supplies. By applying IPM products, a lot of energy can be saved.

IPM integrates three technologies of power switching devices, control drive circuits, and power packaging. Among them, controlling the driving circuit is the key, and it is necessary to provide driving and perfect protection functions for the application of IPM.

The Chinese utility model application with the application number 200620168563.2 discloses a modular power element IGBT driver. Its control signal input and fault signal output are isolated from the internal circuit through an optical fiber interface, and the power supply is an isolated single positive power supply. The optical fiber interface is complicated, the cost is high, and there is no negative power supply. In the application of high voltage and high current, false triggering is easy to occur, resulting in false triggering of power switching devices. No temperature sampling, no current sampling function.

The Chinese invention patent with the application number 011300450.0 discloses an insulated gate bipolar transistor IGBT drive protection circuit. Its control signal input and fault signal output are isolated by a photocoupler. The power supply is a single positive power supply, no negative power supply, and no temperature. Sampling, no current sampling function.

Utility model content

The technical problem to be solved by the utility model is to provide a special thick-film circuit for drive control of an IPM power switch device, which is used to solve the problem that the IGBT cannot be effectively driven and protected in the prior art.

In order to achieve the above purpose, the utility model provides a special thick film circuit for drive control of IPM power switching devices, which is characterized in that it includes: a first photocoupler for isolating control signals, a first photocoupler for isolating fault signals The second photocoupler, signal processing, logic control and drive protection unit, power amplification unit, drive control unit, fault feedback unit, short circuit detection unit, current sampling unit, temperature detection unit;

The control signal passes through the first optocoupler; then sequentially processed by the signal processing, logic control and drive protection unit, and the power amplification unit to obtain an amplified control signal; the amplified control signal Enter the drive control unit to drive the IPM power switch device;

The fault signal enters the fault feedback unit after being processed by the signal processing, logic control and drive protection unit, and is output after being isolated by the second photocoupler after being fed back by the fault feedback unit;

The short-circuit detection unit is connected to the signal processing, logic control and drive protection unit to detect the short-circuit fault of the IPM power switching device;

The current sampling unit is connected to the signal processing, logic control and drive protection unit, and samples the working current of the IPM power switching device through an external current sensor;

The temperature detection unit is connected with the signal processing, logic control and drive protection unit, and detects the operating temperature of the IPM power switching device through an external temperature sensor.

The dedicated thick film circuit for drive control, further comprising: an input signal interface unit for receiving the control signal passing through the first optocoupler, which is arranged on the first optocoupler, the signal Between processing, logic control and drive protection units.

The dedicated thick-film circuit for drive control further includes: an input signal lock unit for locking the control signal, which is provided in the input signal interface unit, the signal processing, logic control and drive protection unit between.

The dedicated thick-film circuit for drive control further includes: a negative voltage source unit for providing a negative drive voltage to the drive control unit, which is arranged in the signal processing, logic control and drive protection unit, the drive between control units.

The dedicated thick film circuit for drive control, further comprising: a reference voltage source unit for providing a reference voltage source to the current sampling unit and the temperature detection unit, connected to the current sampling unit, the temperature detection unit unit.

In the thick film circuit dedicated to drive control, the positive voltage source input unit for providing a positive voltage source is arranged between the signal processing, logic control and drive protection unit, and the reference voltage source unit.

The dedicated thick film circuit for drive control, wherein the negative voltage source unit includes: a controller (E9), a field effect transistor (Q5), an inductor (L1), a fifth voltage regulator transistor (Z5), a first capacitor (C1), the second capacitor (C2), the third capacitor (C3), the seventh capacitor (C7), the third and third resistors (R33), the third and fourth resistors (R34), the third and fifth resistors (R35), the first Thirty-six resistors (R36), thirty-seventh resistors (R37), thirty-eighth resistors (R38);

The first capacitor (C1) is connected to the controller (E9) in parallel, the positive end is connected to the reference voltage source (Vr), and the negative end is grounded; one end of the second capacitor (C2) is connected to the controller (E9), and the other end is connected to the controller (E9). One end is grounded; one end of the third capacitor (C3) is connected to one end of the third and seventh resistors (R37) and the voltage source (Vee), and the other end is grounded; one end of the seventh capacitor (C7) is connected in series with the third and fourth resistors (R34) Connect to the controller (E9), and the other end is grounded; the gate of the field effect transistor (Q5) is connected to one end of the third and third resistors (R33) and the controller (E9), the source is connected to one end of the inductor (L1), and the fifth The negative pole of the Zener tube (Z5) and the drain are connected to the other end of the third and third resistors (R33); the other end of the inductance (L1) is connected to the controller (E9) and one end of the third and sixth resistors (R36); the third and fifth One end of the resistor (R35) is grounded, and the other end is connected to the controller (E9); the other end of the third and sixth resistors (R36) is connected to the controller (E9); the other end of the third and seventh resistors (R37) is connected to the third and eighth resistors ( One end of R38) and the controller (E9); the other end of the third and eighth resistors (R38) is connected to the controller (E9).

The dedicated thick film circuit for drive control, wherein the current sampling unit includes: a sixth comparator (E6), second and second resistors (R22), second and fourth resistors (R24), and second and fifth resistors (R25) , the second sixth resistor (R26), the second seventh resistor (R27) and the seventh diode (D7);

Between the positive input terminal of the sixth comparator (E6) and one terminal of the second fourth resistor (R24), one terminal of the second fifth resistor (R25), the negative input terminal and one terminal of the second sixth resistor (R26), the second One end of the seven resistors (R27) is connected, and the output end is connected to the other input end of the NAND gate (E8) of the signal processing, logic control and drive protection unit; the anode of the seventh diode (D7) is connected to the second five The other end of the resistor (R25), the negative electrode is connected to the thermistor with an external negative temperature coefficient; one end of the second and second resistors (R22) is connected to the output end of the sixth comparator (E6), and the other end is connected to the power supply; The other end of the resistor (R24) is connected to the power supply; the other end of the second sixth resistor (R26) is connected to the reference voltage source (Vr); the other end of the second seventh resistor (R27) is grounded.

The dedicated thick film circuit for drive control, wherein the temperature detection unit includes: the seventh comparator (E7), the second and third resistors (R23), the second and eighth resistors (R28), and the second and ninth resistors (R29) , the third zero resistance (R30), the third first resistance (R31), the third second resistance (R32), the eighth diode (D8);

The positive input terminal of the seventh comparator (E7) is connected with one end of the third first resistor (R31) and one end of the third second resistor (R32), the negative input terminal is connected with one end of the second eighth resistor (R28), the second ninth resistor One end of the resistor (R29) is connected, and the output terminal is connected to an input end of the NAND gate (E8) of the signal processing, logic control and drive protection unit; the anode of the eighth diode (D8) is connected to the second ninth resistor ( The other end of R29) and one end of the third zero resistor (R30) are connected, and the negative pole is connected to the external current sensor; one end of the second and third resistors (R23) is connected to the power supply, and the other end is connected to the output of the seventh comparator (E7) ; The other end of the third resistance (R31) is connected to the reference voltage source (Vr), and the other end of the third resistance (R32) is grounded; the other end of the second eighth resistance (R28) is connected to the power supply; the third zero resistance (R30 ) and the other end is grounded.

The dedicated thick film circuit for drive control, wherein the reference voltage source unit includes: a fourth capacitor (C4), a fifth capacitor (C5), a sixth capacitor (C6) and a voltage regulator (E10);

One end of the voltage regulator (E10) is connected to the reference voltage source (Vr), the other end is connected to the power supply, and the third end is grounded; the positive end of the fourth capacitor (C4) is connected to the voltage regulator (E10), and the fifth capacitor (C5) One end, the power supply, and the negative end are grounded; one end of the fifth capacitor (C5) is connected to the voltage stabilizer (E10), the power supply, and the other end is grounded; one end of the sixth capacitor (C6) is connected to the voltage stabilizer (E10), the reference voltage source ( Vr), the other end is grounded.

The utility model adopts the thick film hybrid integration technology to isolate the input control signal and the output fault signal through the photocoupler, and complete the driving of the power switching device IGBT by the signal processing unit, the logic control unit and the power amplification unit, and the short circuit detection The unit, the current sampling unit and the temperature detection unit complete the protection of the power switching device IGBT. When a fault occurs, the power switching device IGBT is turned off, and a fault signal is output at the same time to lock the input signal.

The utility model integrates functions such as input signal interface circuit, power amplifier circuit, overvoltage, undervoltage, overcurrent, overheat detection and protection, and fault signal output into one thick film circuit. Its input logic level is fully compatible with TTL signals, and can be directly interfaced with the output of the microprocessor.

The integrated thick-film circuit dedicated to drive control for IPM products provided by the utility model realizes the perfect drive and protection of the power switching device IGBT, input control signals, and output fault signals for the application characteristics of high voltage and high current. isolation, and integrates negative power supply, temperature sampling interface, current sampling interface, and reference voltage source.

By adopting the special thick-film circuit of the utility model, the design of the IPM product can be conveniently carried out, and the drive and protection of the power switching device can be realized.

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the utility model.

Description of drawings

Figure 1a, Figure 1b, and Figure 1c are schematic diagrams of the appearance of the utility model;

Fig. 2 is a block diagram of the module structure of the present utility model;

Fig. 3 is the schematic circuit diagram of the utility model.

Detailed ways

The technical solution of the present utility model will be further described in more detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Fig. 1a, Fig. 1b and Fig. 1c, it is a schematic diagram of the appearance of the utility model. Among them, Figure 1a is a top view of the packaged IPM drive control dedicated thick film circuit, Figure 1b is a front view of the packaged IPM drive control dedicated thick film circuit; Figure 1c is the left side of the packaged IPM drive control dedicated thick film circuit view.

In Figure 1a, 1 is the upper surface of the thick film circuit dedicated to IPM drive control, on which the model information and the first pin mark are printed; 2 is the first pin of the thick film circuit dedicated to IPM drive control, and 3 is The IPM driver controls the empty pins of the dedicated thick film circuit.

In Figure 1b, 4 is the circuit package, 5 is the lead-out pin of the thick film circuit dedicated to IPM drive control, and the side with free pins is the input side of the thick film circuit dedicated to IPM drive control.

In FIG. 1c, the lead-out pin 5 and the circuit package 4 of the dedicated thick film circuit for IPM drive control are shown.

As shown in Figure 2, it is a block diagram of the module structure of the present invention.

This Fig. 2 shows a special thick film circuit for IPM drive control, which mainly includes: an input signal interface unit 30 for isolating the input signal through the first optocoupler 10, and a fault feedback for isolating the fault signal through the second optocoupler 20 Unit 50, input signal locking unit 40, signal processing, logic control and drive protection unit 60, short circuit detection unit 70, power amplification unit 80 for amplifying drive signals, drive control unit 90, negative voltage source unit 110, current sampling unit 111 , a temperature detection unit 112 , a reference voltage source unit 113 , and a positive power input unit 114 .

The utility model adopts the thick film hybrid integration technology, and the input control signal and the output fault signal are respectively isolated through the first photoelectric coupler 10 and the second photoelectric coupler, and the signal processing, logic control and driving protection unit 60 and power The amplification unit 80 completes the driving of the power switching device IGBT, and the short circuit detection unit 70 , the current sampling unit 111 and the temperature detection unit 112 complete the protection of the power switching device IGBT. When a fault occurs, the power switching device IGBT is turned off, and a fault signal is output at the same time to lock the input signal.

The externally input control signal enters the input signal interface unit 30 after being isolated by the first optocoupler 10, the input signal interface unit 30 is connected with the signal processing, logic control and drive protection unit 60, and the signal is processed by the signal processing, logic control and drive protection unit 60 and then sent to the power amplification unit 80 for power amplification, and the amplified signal is used to drive the power switching device IGBT. When the power switching device IGBT is turned off, the negative voltage source unit 110 provides the driving control unit 90 with a negative driving voltage, so that the power switching device IGBT can be turned off reliably.

Internally generated fault signals are collected by the signal processing, logic control and drive protection unit 60 through the connected short circuit detection unit 70, drive control unit 90, current sampling unit 111, and temperature detection unit 112. After processing, the protection unit 60 feeds back the fault signal through the fault feedback unit 50 connected thereto.

The negative voltage source unit 110 is connected with the signal processing, logic control and drive protection unit 60 and the drive control unit 90 , and the negative voltage source unit 110 provides negative power drive.

The fault signal is fed back by the fault feedback unit 50, and the fault feedback unit 50 is connected to the second optocoupler 20, signal processing, logic control and drive protection unit 60, and the fault signal is isolated by the second optocoupler 20 and then output to the outside controller. At the same time, the input signal locking unit 40 is connected with the input signal interface unit 30, signal processing, logic control and drive protection unit 60, and locks the input control signal when a fault occurs.

The short-circuit detection unit 70 is connected with the signal processing, logic control and drive protection unit 60 , and detects the short-circuit fault of the power switching device IGBT through the short-circuit detection unit 70 .

The drive control unit 90 is connected to the signal processing, logic control and drive protection unit 60 , the drive control unit 90 detects the voltage of the output drive signal, and feeds back to the signal processing, logic control and drive protection unit 60 .

The current sampling unit 111 is connected to the signal processing, logic control and drive protection unit 60 , and the current sampling unit 111 is externally connected to a current sensor to realize current sampling.

The temperature detection unit 112 is connected with the signal processing, logic control and drive protection unit 60, and the temperature detection unit 112 is externally connected with a temperature sensor to realize the detection of the working temperature of the IPM.

The reference voltage source unit 113 is connected to the current sampling unit 111 and the temperature detection unit 112 to provide a reference voltage source for the current sampling unit 111 and the temperature detection unit 112 .

The utility model realizes the perfect driving and protection of the power switching device IGBT and the isolation of the input control signal and the output fault signal through the integrated thick film circuit specially used for drive control of the IPM product, aiming at the application characteristics of high voltage and high current , and integrates negative power supply, temperature sampling interface, current sampling interface, and reference voltage source.

As shown in Figure 3, it is a schematic circuit diagram of the utility model.

In Figure 3, the circuit substrate of the thick film circuit dedicated to IPM drive control uses a 96% AL ₂ O ₃ ceramic plate, which has the advantages of high insulation resistance, good heat dissipation, and high strength compared with the epoxy resin printed board. Conductors, resistors, dielectrics, etc. are printed with paste, and sintered at high temperature, and have high bonding strength with ceramics, so as to fundamentally improve the reliability of the circuit. The resistors used in the special thick film circuit for IPM drive control are all printed thick film resistors. After laser correction, they can reach the required value according to any design. The precision of the resistance value is high, and the temperature coefficient is small, so as to make full use of the substrate space and improve the integration degree.

The circuit configuration of each unit in FIG. 2 is further described below in conjunction with FIG. 3 .

The input signal interface unit 30 is composed of a regulator tube Z1, resistors (R1, R2, R3, R4), and a capacitor C4.

Wherein, the positive electrode of the regulator tube Z1 is grounded, and the negative electrode is connected between the resistors R1 and R2; one end of the resistor R1 is connected in series with the resistor R2, and the other end is connected to the power supply Vcc; the resistors R3 and R4 are connected in series between the resistors R1 and R2; The other end of the resistor R3 is connected to the negative pole of the regulator tube Z1, the other end of the resistor R4 is connected to the ground, and connected in parallel with the capacitor C4; one end of the resistor R1 is connected to the first photocoupler E1.

The input signal locking unit 40 is composed of an amplifier E4, a diode D4, and resistors (R15, R16). When a fault occurs, the input signal is locked.

Wherein, the positive input terminal and the negative input terminal of the amplifier E4 are respectively connected with the positive input terminal and the negative input terminal of the amplifier E3, and the output terminal is connected with the positive pole of the diode D4 and one end of the resistor R19; the negative pole of the diode D4 is connected with one end of the resistor R15, between one end of resistor R16. The other ends of the resistors R15 and R16 are respectively connected to the power supply Vcc and grounded.

The fault feedback unit 50 is composed of a triode Q1 and a resistor R8.

Among them, the base of the triode Q1 is connected to one end of the resistor R12, one end of the resistor R13, and the output end of the comparator E5, and the collector is connected to the second photocoupler E2, and one end of the parallel resistors R9, R10, and R11 , the emitter is grounded. One end of the resistor R8 is connected to the second photocoupler E2, and the other end is connected to the power supply Vcc.

Signal processing, logic control and drive protection unit 60 is composed of comparator E5, NAND gate E8, transistor Q4, diodes (D2, D3, D9), resistors (R10, R11, R12, R13, R17, R18) , to realize the detection of the drive control signal.

Among them, the positive input terminal of the comparator E5 is connected with one end of the resistor R16 and the negative pole of the diode D9, the negative input terminal is connected with the positive pole of the diode D3, one end of the resistor R17 is connected with one end of the resistor R18; the output terminal of the NAND gate E8 is connected with two The positive pole of the stage tube D9.

The emitter of the transistor Q4 is connected to the power supply Vcc, and the base is connected to the other end of the resistor R19; the cathode of the diode D2 is connected to the other end of the resistor R10, and the anode is connected to the negative input of the amplifier E3 and amplifier E4; the cathode of the diode D3 is connected to The other end of resistor R11.

The other end of the resistor R17 is grounded, the other end of the resistor R18 is connected to the collector of the transistor Q4; the other end of the resistor R19 is connected to one end of the resistor R20, the other end of the resistor R20 is connected to the power supply Vcc; the other end of the resistor R12 is connected to the power supply Vcc; the resistor R13 The other end of the ground.

The short-circuit detection unit 70 is composed of a Zener diode Z4, diodes (D5, D6), and resistors (R20, R21). When it detects that the external voltage signal exceeds a safe value, it cooperates with the drive control unit 90 to realize protection.

Among them, the negative pole of the voltage regulator tube Z4 is connected to the base pole of the triode Q4, the other end of the resistor R19, and one end of the resistor R20, and the positive pole is connected to the positive poles of the diodes D5 and D6 connected in series in sequence. The negative poles of the tubes D5 and D6 are connected to the resistor R21.

The power amplifying unit 80 is composed of amplifier E3, triodes (Q2, Q3), and resistors (R5, R6, R7), and amplifies the power of the input signal.

Among them, the output terminal of the amplifier E3 is connected with the anode of the diode D1, one end of the resistor R5 and the bases of the transistors Q2 and Q3; the collector of the transistor Q2 is connected to the power supply Vcc, and the emitter is connected to the emitter of the transistor Q3; The collector is connected to the voltage source Vee; the other end of the resistor R5 is connected to the power supply Vcc; one end of the resistor R6 is connected to the emitter of the transistor Q2 and the emitter of the transistor Q3, and the other end is connected to the positive electrode of the voltage regulator tube Z2; one end of the resistor R7 It is connected with the bases of transistors Q2 and Q3, and the other end is grounded. The negative pole of the Zener tube Z2 is connected to the negative pole of the Zener tube Z3; the positive pole of the Zener tube Z3 is grounded.

The driving control unit 90 is composed of a diode D1 and a resistor R9 to realize the control of the driving signal. Wherein, the cathode of the diode D1 is connected to the other end of the resistor R9.

Negative voltage source unit 110 is composed of controller E9, field effect transistor Q5, inductor L1, voltage regulator transistor Z5, capacitors (C1, C2, C3, C7), and resistors (R33, R34, R35, R36, R37, R38) , realizing the function of a DC/DC converter with reversed polarity, E9 is an integrated DC/DC controller, the output voltage of the negative voltage source unit 110 is sampled through resistors (R37, R38), and fed back to the controller E9, Finally, a stable negative voltage output is obtained.

Among them, the capacitor C1 is connected to the controller E9 in parallel, one end of the positive pole is connected to the reference voltage source Vr, and one end of the negative pole is grounded; one end of the capacitor C2 is connected to the controller E9, and the other end is grounded; one end of the capacitor C3 is connected to the resistor One end of R37 is connected to the voltage source Vee, and the other end is grounded; one end of the capacitor C7 is connected to the controller E9 in series with the resistor R34, and the other end is grounded; the gate of the field effect transistor Q5 is connected to one end of the resistor R33 and the controller E9, and the field effect tube The source of Q5 is connected to one end of the inductor L1 and the negative electrode of the regulator tube Z5; the drain of the field effect transistor Q5 is connected to the other end of the resistor R33; the other end of the inductor L1 is connected to the controller E9 and one end of the resistor R36; the other end of the resistor R34 One end is connected to controller E9; one end of resistor R35 is grounded, the other end is connected to controller E9; the other end of resistor R36 is connected to controller E9; the other end of resistor R37 is connected to one end of resistor R38 and controller E9, and the other end of resistor R38 is connected to Controller E9.

The current sampling unit 111 is composed of a comparator E6, resistors (R22, R24, R25), a diode D7, and resistors (R26, R27). The negative input terminal of the comparator E6 divides the reference voltage through the resistors (R26, R27). To obtain a stable reference voltage, the diode D7 is connected to an external thermistor with a negative temperature coefficient. When the temperature exceeds a safe value, the voltage at the negative input terminal of the comparator E6 is lower than the voltage at the positive input terminal, and the comparator E6 outputs a low level .

Wherein, the positive input terminal of comparator E6 is connected with one end of resistor R24 and one end of resistor 25, the negative input terminal is connected with one end of resistor R26 and one end of resistor R27, and the output terminal is connected with the other input terminal of NAND gate E8; The positive pole of D7 is connected to the other end of the resistor R25, and the negative pole is connected to an external negative temperature coefficient thermistor; one end of the resistor R22 is connected to the output end of the comparator E6, and the other end is connected to the power supply Vcc; the other end of the resistor R24 is connected to the power supply Vcc; The other end of the resistor R26 is connected to the reference voltage source Vr; the other end of the resistor R27 is grounded.

The temperature detection unit 112 is composed of a comparator E7, resistors (R28, R29, R30), a diode D8, and resistors (R31, R32, R23). The positive input terminal of the comparator E7 divides the reference voltage through the resistors (R31, R32). voltage to obtain a stable reference voltage, and the diode D8 is connected to the external current sensor. When the current exceeds the safe value, the voltage of the negative input terminal of the comparator E7 is higher than the voltage of the positive input terminal, and the output of the comparator E7 is low.

Wherein, the positive input terminal of comparator E7 is connected with one end of resistor R31 and one end of R32, between the negative input terminal and one end of resistor R28 and one end of resistor 29, the output terminal is connected with an input terminal of NAND gate E8; diode D8 The positive pole of the resistor is connected to the other end of the resistor R29 and one end of the resistor R30, and the negative pole is connected to the external current sensor. One end of the resistor R23 is connected to the power supply Vcc, the other end is connected to the output end of the comparator E7; the other end of the resistor R31 is connected to the reference voltage source Vr, the other end of the resistor R32 is grounded; the other end of the resistor R28 is connected to the power supply Vcc; the other end of the resistor R30 grounded.

The reference voltage source unit 113 is composed of capacitors (C4, C5, C6) and a voltage regulator E10, and obtains a stable reference voltage after linearly stabilizing the input positive power supply to provide to other circuits; wherein E10 is a three-terminal Stabilizer.

Among them, one end of the voltage regulator E10 is connected to the reference voltage source Vr, the other end is connected to the power supply Vcc, and the third end is grounded; the positive terminal of the capacitor C4 is connected to the voltage regulator E10, one end of the capacitor C5, and the power supply Vcc, and the negative terminal is grounded; the capacitor C5 One end of capacitor C6 is connected to voltage regulator E10, power supply Vcc, and the other end is grounded; one end of capacitor C6 is connected to voltage regulator E10, reference voltage source Vr, and the other end is grounded.

Since IPM products are used in high-voltage and high-current working environments, it is necessary to effectively isolate the external control system from the internal application system to ensure the safety of the external control system. In FIG. 3 , photocouplers E1 (first photocoupler 10 ) and E2 (second photocoupler 20 ) are used to isolate the inside and outside of the system, and the input and output signals undergo photoelectric conversion for data exchange.

After being isolated by the photocoupler E1, the input control signal is processed by the amplifier E3, and the triode (Q2, Q3) constitutes a push-pull power amplifier, and the output signal of the amplifier E3 is amplified and provided to the power switching device IGBT. The current output capacity of the power amplifier is above 2A, and heat will be generated in the working state. Since the circuit substrate is made of ceramic material, the heat dissipation is good, so the triode (Q2, Q3) can be guaranteed to work in a stable temperature range.

When the power switching device IGBT is driven, if the driving voltage is too low, the power switching device IGBT cannot work stably and normally, and at the same time the turn-on loss and turn-off loss will increase sharply, causing damage to the device. If the driving voltage is too high, the power switch The device IGBT may be permanently damaged. The utility model can accurately detect the driving voltage by comparing the set voltage reference with the driving voltage.

Overcurrent and overheating will directly affect the working characteristics and reliability of the power switching device IGBT. Therefore, when carrying out the special thick-film circuit design of the utility model, aiming at the factors affecting the reliability of the power switching device IGBT, the following corresponding protective measures have been taken in a targeted manner:

a1) Protection of the gate of the power switching device IGBT

The guaranteed value of the gate-emitter driving voltage VGE of the power switching device IGBT is ±20V. If a voltage exceeding the guaranteed value is applied between its gate and emitter, the power switching device IGBT may be damaged. The tubes Z2 and Z3 are set as grid voltage limiting circuits to realize the protection of the grid.

a2) Protection against surge voltage

Due to the existence of distributed inductance in the circuit and the high switching speed of the power switching device IGBT, a large surge voltage Ldi/dt will be generated when it is turned off and the reverse recovery diode connected in parallel with it is reverse recovered. , threatening the safety of the power switching device IGBT. When designing a special thick film circuit, by adjusting the resistance R6 of the power switching device IGBT drive circuit, the Ldi/dt in the application system can be made as small as possible.

a3) Overcurrent protection

There are two main methods for overcurrent protection of the power switching device IGBT:

3.1) Use resistance or current transformer to detect overcurrent for protection

A resistor or current transformer can be used in series with the main circuit to detect the current flowing through the main circuit. When an overcurrent situation occurs, the drive signal is disconnected to achieve the purpose of protection. In the utility model, the current sampling value is compared with the reference voltage by the comparator E6, and the current sampling input channel is formed by the resistor R24, the resistor R25, the diode D7 and the external current sampling resistor, and the reference voltage source is passed through the resistor R26, the resistor R27 The voltage divider provides a reference voltage.

3.2) Protected by VCE(sat) detecting overcurrent

Because VCE(sat)=Ic*RCE(sat), when Ic increases, VCE(sat) also increases. If the gate voltage is high and VCE(sat) is high, then the When an overcurrent situation occurs, the AND gate outputs a high level at this time, outputs an overcurrent signal, and disconnects the driving signal to achieve the purpose of protection. In the utility model, VCE (sat) is detected through the resistor R20, the voltage regulator tube Z4, the diode D5, the diode D6, and the resistor R21. Among them, VCE(sat) is the saturated voltage drop, RCE(sat) is the saturated resistance, and Ic is the current.

a4) Overheat protection

Due to the large current flowing through the power switching device IGBT and the high switching frequency, the loss of the power switching device IGBT is relatively large. If the heat cannot be dissipated in time, the junction temperature Tj of the power switching device IGBT exceeds Tjmax, and the power switch Device IGBT may be damaged. The working temperature can be detected by a temperature sensor installed close to the heating place. When the temperature exceeds the safe value, the thick film circuit can cut off the driving signal to protect its safety. In the utility model, the overheat detection is performed by the comparator E7, the resistors (R28, R29, R30), the diode D8 and the external thermistor form a temperature detection channel, and the reference voltage source provides a reference voltage through the voltage division of the resistors (R31, R32) .

In the utility model, when a short circuit, overcurrent, undervoltage, overvoltage, or overheating fault occurs within the effective time of the driving signal, a fault signal will be generated after passing through the logic circuit, and the driving signal will be turned off at this time, and the fault signal will be output , to lock the input signal.

When the power switching device IGBT is turned off, the gate should be reverse-biased. Due to the large impedance of the gate, the current will increase VGE. When the threshold voltage is reached under harsh conditions, false triggering will occur, causing the upper and lower arm Turning on at the same time short-circuits the bridge arms. Therefore, in the utility model, by controller E9, capacitor (C1, C2, C3, C7), triode Q5, voltage regulator tube Z5, inductance L1, resistance (R33, R34, R35, R36, R37, R38) The negative power supply circuit constituted can provide enough negative grid voltage to the gate to make it turn off reliably.

The overall performance of IPM products is very superior, and it cannot be replaced by other power devices, so it has become the main device in today's power electronics technology. It is very important to correctly select the capacity of the device when using it, to have a completely strict protection circuit, and to correctly select various parameter values and protection values according to the technical performance regulations of the product. Only with careful design and standardized operation can the Ensure safety and reliability in use.

The development trend of IPM products is high withstand voltage, high current, high speed, low dropout, high reliability, and low cost. In particular, the application of high-voltage inverters is developed to simplify the main circuit, reduce the use of components, improve reliability, and reduce Manufacturing costs, simplified commissioning work, etc.

The utility model is packaged with epoxy resin after the production and testing are completed, the overall performance of the circuit is stable, the consistency is good, the integration degree is high, and the performance of the products in the IPM products can be improved.

The utility model provides a special thick-film circuit for IPM drive control, which includes a thick-film circuit and a form of lead-out terminals. , Overcurrent detection, temperature signal detection, current signal detection, input signal isolation, processing circuit. The input signal is TTL level and can be directly connected to the microprocessor. The input signal is isolated and amplified and then output to drive the power switch device IGBT of the IPM product. And through the logic protection circuit to detect the saturation voltage drop of the power switching device IGBT, to detect the overcurrent and short circuit fault status of the IPM product, at the same time, it has a temperature signal sampling interface and a current signal sampling interface, and can detect the temperature and current of the IPM product through an external sensor . The fault signal is fed back to the external controller through the isolated signal processing, logic control and drive protection unit 60. The circuit is integrated with a voltage reference source circuit and a negative power supply circuit, which can ensure the reliability of the power switching device IGBT in high voltage and high current applications. Work. The utility model adopts thick film mixed integration technology, has high integration degree, high reliability, simple external interface structure and convenient maintenance, and is very suitable for the design and manufacture of IPM products.

The special thick film circuit for IPM drive control of the utility model has the following characteristics:

1) It simplifies the complex design of IPM products, reduces the volume of IPM, improves reliability, simplifies layout and wiring, and can make it an easy-to-use integrated power device.

2) The internal circuit and wiring design are optimized to effectively suppress interference; the adjusted drive circuit can reduce on-state loss and switching loss, making the radiator area required for IPM products smaller; using standardized logic level control circuit interfaces to expand There is no need to design additional drive circuits for specifications, and it has powerful automatic protection and fault detection functions.

3) The current real-time monitoring technology through the input interface of the current sensor can efficiently and quickly detect over-current and short-circuit current, and adopts the soft-off technology of gradually reducing the gate voltage, which greatly reduces the surge voltage caused by turning off the large current ; And can give enough protection to the power switching device IGBT, reduce the failure rate of IPM products.

4) The working temperature of the power switching device IGBT can be detected through the temperature sensor input interface, and when the temperature exceeds the safety threshold, the power switching device IGBT is quickly turned off.

5) Through the overvoltage protection and undervoltage lockout of the IGBT gate voltage of the power switching device, the permanent damage of the power switching device caused by the failure of the driving signal voltage is avoided.

6) By turning off the negative voltage of the power switching device IGBT, the power switching device IGBT can work reliably in the application of high voltage and high current.

Of course, the utility model can also have other various embodiments, and those skilled in the art can make various corresponding changes and deformations according to the utility model without departing from the spirit and essence of the utility model, but These corresponding changes and deformations should all belong to the protection scope of the appended claims of the present utility model.

Claims (10)

1, a kind of special-purpose thick film circuit of drive controlling that is used for the IPM device for power switching, it is characterized in that, comprise: be used for first photoelectrical coupler of isolation control signal, be used for second photoelectrical coupler of isolated fault signal, signal processing, logic control and driving protected location, power amplification unit, driving control unit, fault feedback unit, short-circuit detecting unit, current sampling unit, temperature detecting unit;

Described control signal is by described first photoelectrical coupler; Handle the control signal after obtaining amplifying through described signal processing, logic control and driving protected location, described power amplification unit successively again; Control signal after the described amplification enters described driving control unit, drives described IPM device for power switching;

Described fault-signal enters described fault feedback unit after handling through described signal processing, logic control and driving protected location, after described fault feedback unit feedback, by exporting after described second photoelectric coupler isolation;

Described short-circuit detecting unit is connected with the driving protected location with described signal processing, logic control, detects the short trouble of described IPM device for power switching;

Described current sampling unit is connected with the driving protected location with described signal processing, logic control, by the sample operating current of described IPM device for power switching of external current sensor;

Described temperature detecting unit is connected with the driving protected location with described signal processing, logic control, detects the working temperature of described IPM device for power switching by external temperature sensor.

2, the special-purpose thick film circuit of drive controlling according to claim 1; it is characterized in that; also comprise: be used to receive input signal interface unit, be arranged between described first photoelectrical coupler, described signal processing, logic control and the driving protected location by the described control signal of described first photoelectrical coupler.

3, the special-purpose thick film circuit of drive controlling according to claim 2; it is characterized in that; also comprise: be used for input signal lock cell that described control signal is locked, be arranged between described input signal interface unit, described signal processing, logic control and the driving protected location.

4, the special-purpose thick film circuit of drive controlling according to claim 1; it is characterized in that; also comprise: be used for providing the negative voltage source unit of negative driving voltage, be arranged between described signal processing, logic control and driving protected location, the described driving control unit to described driving control unit.

5, according to claim 1,2, the special-purpose thick film circuit of 3 or 4 described drive controlling, it is characterized in that, also comprise: be used for providing the reference voltage source unit of reference voltage source, connect described current sampling unit, described temperature detecting unit to described current sampling unit, described temperature detecting unit.

6, the special-purpose thick film circuit of drive controlling according to claim 5; it is characterized in that; also comprise: be used to provide the positive voltage source input unit of positive voltage source, be arranged between described signal processing, logic control and driving protected location, the described reference voltage source unit.

7, according to claim 4 or the special-purpose thick film circuit of 6 described drive controlling, it is characterized in that described negative voltage source unit comprises: controller (E9), field effect transistor (Q5), inductance (L1), the 5th voltage-stabiliser tube (Z5), first electric capacity (C1), second electric capacity (C2), the 3rd electric capacity (C3), the 7th electric capacity (C7), the three or three resistance (R33), the three or four resistance (R34), the three or five resistance (R35), the three or six resistance (R36), pseudo-ginseng resistance (R37), the three or eight resistance (R38);

First electric capacity (C1) is received controller (E9) with parallel way, on the anodal termination reference voltage source (Vr), and negative pole end ground connection; One of second electric capacity (C2) terminates on the controller (E9), other end ground connection; One of the 3rd electric capacity (C3) terminates to an end and the voltage source (Vee) of pseudo-ginseng resistance (R37), other end ground connection; One end and the three or four resistance (R34) of the 7th electric capacity (C7) are concatenated into controller (E9), other end ground connection; The grid of field effect transistor (Q5) connects an end and the controller (E9) of the three or three resistance (R33), and source electrode connects an end of inductance (L1), the negative pole of the 5th voltage-stabiliser tube (Z5), and drain electrode connects the other end of the three or three resistance (R33); An another termination controller (E9) of inductance (L1) and an end of the three or six resistance (R36); One end ground connection of the three or five resistance (R35), another termination controller (E9); Another termination controller (E9) of the three or six resistance (R36); One end of another termination the three or eight resistance (R38) of pseudo-ginseng resistance (R37), controller (E9); Another termination controller (E9) of the three or eight resistance (R38).

8, according to claim 1,2,3, the special-purpose thick film circuit of 4 or 6 described drive controlling, it is characterized in that described current sampling unit comprises: the 6th comparator (E6), the two or two resistance (R22), the two or four resistance (R24), the two or five resistance (R25), the two or six resistance (R26), the two or seven resistance (R27) and the 7th diode (D7);

Between one end of the positive input terminal of the 6th comparator (E6) and an end of the two or four resistance (R24), the two or five resistance (R25), negative input end is connected with an end of the two or six resistance (R26), an end of the two or seven resistance (R27), another input of the NAND gate (E8) of the described signal processing of output termination, logic control and driving protected location; The positive pole of the 7th diode (D7) connects the other end of the two or five resistance (R25), and negative pole is connected with the thermistor of external negative temperature coefficient; The output of one termination the 6th comparator (E6) of the two or two resistance (R22), another termination power; Another termination power of the two or four resistance (R24); Another termination reference voltage source (Vr) of the two or six resistance (R26); The other end ground connection of the two or seven resistance (R27).

9, according to claim 1,2,3, the special-purpose thick film circuit of 4 or 6 described drive controlling, it is characterized in that described temperature detecting unit comprises: the 7th comparator (E7), the two or three resistance (R23), the two or eight resistance (R28), the two or nine resistance (R29), the 3rd zero resistance (R30), the 31 resistance (R31), the three or two resistance (R32), the 8th diode (D8);

The positive input terminal of the 7th comparator (E7) is connected with an end of the 31 resistance (R31), an end of the three or two resistance (R32), negative input end is connected with an end of the two or eight resistance (R28), an end of the two or nine resistance (R29), an input of the NAND gate (E8) of the described signal processing of output termination, logic control and driving protected location; The positive pole of the 8th diode (D8) is connected with an end of the other end of the two or nine resistance (R29), the 3rd zero resistance (R30), and negative pole is connected with external current sensor; One termination power of the two or three resistance (R23), the output of another termination the 7th comparator (E7); Another termination reference voltage source (Vr) of the 31 resistance (R31), the other end ground connection of the three or two resistance (R32); Another termination power of the two or eight resistance (R28); The other end ground connection of the 3rd zero resistance (R30).

10, the special-purpose thick film circuit of drive controlling according to claim 5 is characterized in that described reference voltage source unit comprises: the 4th electric capacity (C4), the 5th electric capacity (C5), the 6th electric capacity (C6) and pressurizer (E10);

One termination reference voltage source (Vr) of pressurizer (E10), another termination power, the 3rd end ground connection; The anodal termination pressurizer (E10) of the 4th electric capacity (C4), an end, the power supply of the 5th electric capacity (C5), negative pole end ground connection; One termination pressurizer (E10) of the 5th electric capacity (C5), power supply, other end ground connection; One termination pressurizer (E10) of the 6th electric capacity (C6), reference voltage source (Vr), other end ground connection.

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