Novel PTC controller of single IGBT

Abstract

The utility model relates to a novel PTC controller with a single I-GBT. Comprising a PWM drive circuit used for controlling on-off of a primary coil of an isolation transformer based on PWM signals, and the isolation transformer used for outputting interval on-off control signals at a secondary coil based on on-off of the primary coil. The PWM driving circuit is used for outputting a control signal, the rectifying circuit is used for rectifying the control signal output by the isolation transformer and outputting a rectified square wave signal, the IGBT module is used for controlling the on-off time of an IGBT based on the square wave signal, the input end of the PWM driving circuit is connected with a PWM signal, and the output end of the PWM driving circuit is connected with a primary coil of the isolation transformer. A secondary coil of the isolation transformer is connected with the input end of the rectification circuit, and the output end of the rectification circuit is connected with the IGBT module. According to the utility model, the low-voltage end outputs PWM to control the on / off of the high-voltage end I-GBT, so that the circuit is safer, has no high-frequency power switch, has a better EMC effect, and is simple and lower in cost.

Description

Technical Field

[0001] The utility model relates to the technical field of control of automobile thermal management systems, in particular to a novel PTC controller of a single IGBT. Background Art

[0002] With the development of new energy vehicles, the application of PTC heaters is becoming more and more extensive, and the types of controllers are also increasing. In the early days, potentiometers or relays were used to control voltage and current, which was rough and had large power errors. Later, digital signal processing chips were used for PID control, which improved the accuracy but the response speed was still slow. Utility Model Content

[0003] In view of the technical defects and technical drawbacks in the prior art, the embodiment of the utility model provides a new PTC controller with a single IGBT that overcomes the above problems or at least partially solves the above problems. The specific solution is as follows:

[0004] A novel PTC controller with a single IGBT comprises: a PWM drive circuit for controlling the on and off of a primary coil of an isolation transformer based on a PWM signal, an isolation transformer for outputting a control signal for interval on and off of a secondary coil based on the on and off of the primary coil, a rectifier circuit for rectifying the control signal output by the isolation transformer and outputting a rectified square wave signal, and an IGBT module for controlling the on and off time of the IGBT based on the square wave signal, wherein the PWM drive circuit input end is connected to the PWM signal, and the output end is connected to the primary coil of the isolation transformer, the secondary coil of the isolation transformer is connected to the input end of the rectifier circuit, and the output end of the rectifier circuit is connected to the IGBT module.

[0005] Furthermore, the PTC controller further comprises an MCU for outputting a PWM signal, and an input end of the PWM driving circuit is connected to the MCU to receive the PWM signal output by the MCU.

[0006] Furthermore, the PWM drive circuit includes a transistor Q1, a resistor R1, a resistor R2, a resistor R3 and a diode D1, the base of the transistor Q1 is connected to the PWM signal through the resistor R1, the resistor R2 is connected between the base and the emitter of the transistor Q1, the collector of the transistor Q1 is grounded, the positive electrode of the diode D1 is connected to the emitter of the transistor Q1, the negative electrode is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the VCC1 power supply, and one end of the primary coil of the isolation transformer is connected to the emitter of the diode D1, and the other end is connected to the VCC1 power supply.

[0007] Furthermore, the rectifier circuit includes a diode D2 and a resistor R4, the diode D2 and the resistor R4 are connected in series, the positive electrode of the diode D2 is connected to one end of the secondary coil of the isolation transformer, the negative electrode is connected to the gate of the IGBT in the IGBT module, and the other end of the secondary coil of the isolation transformer is connected to the emitter of the IGBT.

[0008] Furthermore, the IGBT module includes a diode D3, a capacitor C1, a resistor R5, a transient suppression diode D4 and an IBGT. The diode D3, the capacitor C1, the resistor R5 and the transient suppression diode D4 are connected in parallel. The positive electrode of the diode D3 is connected to the emitter of the IGBT, the negative electrode is connected to the gate of the IGBT, and the collector of the IGBT is connected to the high voltage signal HVCC.

[0009] Furthermore, the PTC controller also includes an isolated current sampling circuit for collecting load current, wherein the input end of the isolated current sampling circuit is connected to the emitter of the IGBT in the IGBT module, and the output end is connected to the MCU for transmitting the collected load current to the MCU.

[0010] Furthermore, the isolated current sampling circuit includes a Hall current sensor chip and its peripheral circuit, the peripheral circuit includes a diode D5, a resistor R6, a resistor R7, a capacitor C2, a capacitor C3 and a capacitor C4, the IP+ signal pin of the Hall current sensor chip is connected to the emitter of the IGBT in the IGBT module, and the IP- signal pin is grounded; the VIOUT signal pin of the Hall current sensor chip is connected to the positive electrode of the diode D5 through the resistor R6, and is connected to the MCU through the negative electrode of the diode D5; the GND signal pin of the Hall current sensor chip is grounded, the FILTER signal pin is grounded through the capacitor C4, the VCC signal pin is connected to a 5V power supply, and the VCC signal pin is also grounded through the capacitor C2; one end of the capacitor C3 is connected to the negative electrode of the diode D5, and the other end is grounded; one end of the resistor R7 is connected to the positive electrode of the diode D5, and the other end is grounded.

[0011] Furthermore, the PTC controller also includes an isolated voltage sampling circuit for collecting high-voltage terminal voltage signals, the input end of the isolated voltage sampling circuit is connected to the collector of the IGBT in the IGBT module, and the output end is connected to the MCU for transmitting the collected voltage signal to the MCU.

[0012] Furthermore, the isolated voltage sampling circuit includes an effective series resistor RS1, an effective series resistor RS2, an isolated operational amplifier OP1, an operational amplifier OP2, a resistor R8, a resistor R9, a resistor R10, a resistor R11 and a resistor R12, a capacitor C5, a capacitor C6 and a capacitor C7; the effective series resistor RS1 and the effective series resistor RS2 are connected in series and the two ends of the effective series resistor RS2 are respectively connected to the two input ends of the isolated operational amplifier OP1; one input end of the isolated operational amplifier OP1 is connected to the collector of the IGBT in the IGBT module through the effective series resistor RS1, and the other input end is grounded, and the One output end of the isolation operational amplifier OP1 is connected to the positive input end of the operational amplifier OP2 through a resistor R8; the other output end of the isolation operational amplifier OP1 is connected to the negative input end of the operational amplifier OP2 through a resistor R11; one end of the resistor R9 is connected to the output end of the operational amplifier OP2, and the other end is connected to the MCU, and the other end of the resistor R9 is also grounded through a capacitor C6; the capacitor C5 and the resistor R10 are both connected between the positive input end and the output end of the operational amplifier OP2; one end of the capacitor C7 and the resistor R12 is connected to the negative input end of the operational amplifier OP2, and the other end is grounded.

[0013] The utility model has the following beneficial effects:

[0014] 1. It is safer to control the on / off of the high-voltage IGBT by outputting PWM at the low-voltage end.

[0015] 2. Without high-frequency power switching, the EMC effect is better.

[0016] 3. The circuit is simple and the cost is relatively low.

[0017] 4. The overall structure is simple and the design is relatively simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A structural diagram of a new PTC controller with a single IGBT provided in an embodiment of the utility model

[0019] Figure 2 A structural diagram of another novel PTC controller with a single IGBT provided in an embodiment of the utility model;

[0020] Figure 3 A circuit schematic diagram of a novel PTC controller with a single IGBT provided in an embodiment of the utility model;

[0021] Figure 4 A circuit schematic diagram of an isolated voltage sampling circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the utility model, not all embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] See also Figure 1 As shown, a new PTC controller with a single IGBT provided by an embodiment of the utility model includes: a PWM drive circuit for controlling the on and off of the primary coil of the isolation transformer based on a PWM signal, an isolation transformer for outputting a control signal for interval on and off of the secondary coil based on the on and off of the primary coil, a rectifier circuit for rectifying the control signal output by the isolation transformer and outputting the rectified square wave signal, and an IGBT module for controlling the on and off time of the IGBT based on the square wave signal, the PWM drive circuit input end is connected to the PWM signal, the output end is connected to the primary coil of the isolation transformer, the secondary coil of the isolation transformer is connected to the input end of the rectifier circuit, and the output end of the rectifier circuit is connected to the IGBT module.

[0024] The utility model controls the on / off of the high-voltage end IGBT by outputting PWM at the low-voltage end, which is safer. The utility model does not have a high-frequency power switch, so the EMC effect is better. The utility model has a simple circuit and a relatively lower cost.

[0025] See also Figure 2As shown, optionally, the PTC controller also includes an MCU, an LDO power supply circuit, an IGBT temperature sampling circuit, a PCB temperature sampling circuit, a core temperature sampling circuit, a LIN communication circuit, and a 12V sampling circuit; the PTC controller also includes an MCU for outputting a PWM signal, the input end of the PWM drive circuit is connected to the MCU to access the PWM signal output by the MCU, the input end of the LDO power supply circuit is connected to the 12V power supply through a filtering protection circuit, and the output end is connected to the MCU, and is used to convert the power supply voltage from 12V to 5V and then power the MCU, and the LIN module circuit is used to convert the LIN communication into a communication type that the MCU can recognize The IGBT temperature sampling circuit is used to collect the working temperature of the IGBT module in real time and transmit it to the MCU. The 12V power supply sampling circuit is used to sample the 12V power supply voltage and transmit it to the MCU. The MCU also determines whether the power supply voltage is abnormal through the 12V power supply voltage sampled by the 12V power supply sampling circuit, and cuts off the 12V power supply when the power supply voltage exceeds the preset range, thereby avoiding irreversible damage to the system. The PCB temperature sampling circuit is used to sample the change of PCB temperature and transmit it to the MCU. The core temperature sampling circuit is used to sample the change of core temperature and transmit it to the MCU. The MCU is also used to adjust the duty cycle of the PWM signal based on the core temperature to achieve P TC power regulation.

[0026] See also Figure 3 As shown, optionally, the PWM drive circuit includes a transistor Q1, a resistor R1, a resistor R2, a resistor R3 and a diode D1, wherein the resistor R3 is preferably a 0603 chip resistor, the base of the transistor Q1 is connected to the MCU through the resistor R1 to receive the PWM signal sent by the MCU, the resistor R2 is connected between the base and the emitter of the transistor Q1, the collector of the transistor Q1 is grounded, the positive electrode of the diode D1 is connected to the emitter of the transistor Q1, the negative electrode is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the VCC1 power supply, one end of the primary coil of the isolation transformer is connected to the emitter of the diode D1, and one end is connected to the VCC1 power supply; the rectifier circuit includes The invention comprises a diode D2 and a resistor R4, wherein the diode D2 and the resistor R4 are connected in series, the positive electrode of the diode D2 is connected to one end of the secondary coil of the isolation transformer, the negative electrode is connected to the gate of the IGBT in the IGBT module, and the other end of the secondary coil of the isolation transformer is connected to the emitter of the IGBT; the IGBT module comprises a diode D3, a capacitor C1, a resistor R5, a transient suppression diode D4 and an IBGT, wherein the resistor R5 is a 0603 chip resistor, the diode D3, the capacitor C1, the resistor R5 and the transient suppression diode D4 are connected in parallel, the positive electrode of the diode D3 is connected to the emitter of the IGBT, the negative electrode is connected to the gate of the IGBT, and the collector of the IGBT is connected to the high voltage signal HVCC.

[0027] In the above embodiment, the VCC1 is 12V and is supplied by a 12v power supply. The MCU outputs a PWM signal to control the transistor Q1 to realize the disconnection / connection of the primary coil of the isolation transformer. The secondary coil of the isolation transformer responds to the disconnection / connection of the primary coil and outputs an interval on-off control signal to the rectifier circuit. After rectification by the diode D2, a square wave is output, thereby realizing the driving of the IGBT. In addition, the MCU further controls the duty cycle of the PWM signal to further realize the time proportion of the IGBT opening, thereby realizing power control.

[0028] Optionally, the PTC controller further comprises an isolated current sampling circuit for collecting load current, wherein the input end of the isolated current sampling circuit is connected to the emitter of the IGBT in the IGBT module, and the output end is connected to the MCU, so as to transmit the collected load current to the MCU.

[0029] See also Figure 3 As shown, the isolated current sampling circuit includes a Hall current sensor chip and its peripheral circuit, the peripheral circuit includes a diode D5, a resistor R6, a resistor R7, a capacitor C2, a capacitor C3 and a capacitor C4, the IP+ signal pin of the Hall current sensor chip is connected to the emitter of the IGBT in the IGBT module, and the IP- signal pin is grounded; the VIOUT signal pin of the Hall current sensor chip is connected to the positive electrode of the diode D5 through the resistor R6, and is connected to the MCU through the negative electrode of the diode D5; the GND signal pin of the Hall current sensor chip is grounded, the FILTER signal pin is grounded through the capacitor C4, the VCC signal pin is connected to the 5V power supply, and the VCC signal pin is also grounded through the capacitor C2; one end of the capacitor C3 is connected to the negative electrode of the diode D5, and the other end is grounded; one end of the resistor R7 is connected to the positive electrode of the diode D5, and the other end is grounded.

[0030] In the above embodiment, the load current can be monitored in real time through the isolated current sampling circuit, and the PTC power can be adjusted in real time based on the load current.

[0031] Optionally, the PTC controller also includes an isolated voltage sampling circuit for collecting high-voltage terminal voltage signals, wherein the input end of the isolated voltage sampling circuit is connected to the collector of the IGBT in the IGBT module, and the output end is connected to the MCU for transmitting the collected voltage signal to the MCU.

[0032] See also Figure 4As shown, the isolated voltage sampling circuit includes an effective series resistor RS1, an effective series resistor RS2, an isolated operational amplifier OP1, an operational amplifier OP2, a resistor R8, a resistor R9, a resistor R10, a resistor R11 and a resistor R12, a capacitor C5, a capacitor C6 and a capacitor C7; the effective series resistor RS1 and the effective series resistor RS2 are connected in series and the two ends of the effective series resistor RS2 are respectively connected to the two input ends of the isolated operational amplifier OP1; one input end of the isolated operational amplifier OP1 is connected to the collector of the IGBT in the IGBT module through the effective series resistor RS1, and the other input end is grounded. One output end of the isolation operational amplifier OP1 is connected to the positive input end of the operational amplifier OP2 through a resistor R8; the other output end of the isolation operational amplifier OP1 is connected to the negative input end of the operational amplifier OP2 through a resistor R11; one end of the resistor R9 is connected to the output end of the operational amplifier OP2, and the other end is connected to the MCU, and the other end of the resistor R9 is also grounded through a capacitor C6; the capacitor C5 and the resistor R10 are both connected between the positive input end and the output end of the operational amplifier OP2; one end of the capacitor C7 and the resistor R12 is connected to the negative input end of the operational amplifier OP2, and the other end is grounded.

[0033] In the above embodiment, the voltage signal at the high voltage end is transmitted to the low voltage end through the isolation operational amplifier, thereby realizing isolated voltage sampling.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A new PTC controller with a single IGBT, characterized in that: include: A PWM drive circuit for controlling the on and off of the primary coil of an isolation transformer based on a PWM signal, an isolation transformer for outputting a control signal for interval on and off of the secondary coil based on the on and off of the primary coil, a rectifier circuit for rectifying the control signal output by the isolation transformer and outputting the rectified square wave signal, and an IGBT module for controlling the on and off time of the IGBT based on the square wave signal, wherein the input end of the PWM drive circuit is connected to the PWM signal, and the output end is connected to the primary coil of the isolation transformer, the secondary coil of the isolation transformer is connected to the input end of the rectifier circuit, and the output end of the rectifier circuit is connected to the IGBT module.

2. The novel PTC controller with a single IGBT according to claim 1 is characterized in that: The PTC controller further comprises an MCU for outputting a PWM signal, and an input end of the PWM driving circuit is connected to the MCU to access the PWM signal output by the MCU.

3. The novel PTC controller with a single IGBT according to claim 1 is characterized in that: The PWM drive circuit includes a transistor Q1, a resistor R1, a resistor R2, a resistor R3 and a diode D1. The base of the transistor Q1 is connected to the PWM signal through the resistor R1. The resistor R2 is connected between the base and the emitter of the transistor Q1. The collector of the transistor Q1 is grounded. The positive electrode of the diode D1 is connected to the emitter of the transistor Q1, and the negative electrode is connected to one end of the resistor R3. The other end of the resistor R3 is connected to the VCC1 power supply. One end of the primary coil of the isolation transformer is connected to the emitter of the diode D1, and the other end is connected to the VCC1 power supply.

4. The novel PTC controller with a single IGBT according to claim 1, characterized in that: The rectifier circuit includes a diode D2 and a resistor R4, wherein the diode D2 and the resistor R4 are connected in series, the positive electrode of the diode D2 is connected to one end of the secondary coil of the isolation transformer, the negative electrode is connected to the gate of the IGBT in the IGBT module, and the other end of the secondary coil of the isolation transformer is connected to the emitter of the IGBT.

5. The novel PTC controller with a single IGBT according to claim 2, characterized in that: The IGBT module includes a diode D3, a capacitor C1, a resistor R5, a transient suppression diode D4 and an IBGT. The diode D3, the capacitor C1, the resistor R5 and the transient suppression diode D4 are connected in parallel. The positive electrode of the diode D3 is connected to the emitter of the IGBT, the negative electrode is connected to the gate of the IGBT, and the collector of the IGBT is connected to the high voltage signal HVCC.

6. The novel PTC controller with a single IGBT according to claim 1, characterized in that: The PTC controller also includes an isolated current sampling circuit for collecting load current. The input end of the isolated current sampling circuit is connected to the emitter of the IGBT in the IGBT module, and the output end is connected to the MCU to transmit the collected load current to the MCU.

7. The novel PTC controller with a single IGBT according to claim 6, characterized in that: The isolated current sampling circuit includes a Hall current sensor chip and its peripheral circuit, wherein the peripheral circuit includes a diode D5, a resistor R6, a resistor R7, a capacitor C2, a capacitor C3 and a capacitor C4, the IP+ signal pin of the Hall current sensor chip is connected to the emitter of the IGBT in the IGBT module, and the IP- signal pin is grounded; the VIOUT signal pin of the Hall current sensor chip is connected to the positive electrode of the diode D5 through the resistor R6, and is connected to the MCU through the negative electrode of the diode D5; the GND signal pin of the Hall current sensor chip is grounded, the FILTER signal pin is grounded through the capacitor C4, the VCC signal pin is connected to a 5V power supply, and the VCC signal pin is also grounded through the capacitor C2; one end of the capacitor C3 is connected to the negative electrode of the diode D5, and the other end is grounded; one end of the resistor R7 is connected to the positive electrode of the diode D5, and the other end is grounded.

8. The novel PTC controller with a single IGBT according to claim 1, characterized in that: The PTC controller also includes an isolated voltage sampling circuit for collecting high-voltage terminal voltage signals. The input end of the isolated voltage sampling circuit is connected to the collector of the IGBT in the IGBT module, and the output end is connected to the MCU for transmitting the collected voltage signal to the MCU.

9. The novel PTC controller with a single IGBT according to claim 8, characterized in that: The isolated voltage sampling circuit includes an effective series resistor RS1, an effective series resistor RS2, an isolated operational amplifier OP1, an operational amplifier OP2, a resistor R8, a resistor R9, a resistor R10, a resistor R11 and a resistor R12, a capacitor C5, a capacitor C6 and a capacitor C7; the effective series resistor RS1 and the effective series resistor RS2 are connected in series and the two ends of the effective series resistor RS2 are respectively connected to the two input ends of the isolated operational amplifier OP1; one input end of the isolated operational amplifier OP1 is connected to the collector of the IGBT in the IGBT module through the effective series resistor RS1, and the other input end is grounded. One output end of the operational amplifier OP1 is connected to the positive input end of the operational amplifier OP2 through a resistor R8; the other output end of the isolation operational amplifier OP1 is connected to the negative input end of the operational amplifier OP2 through a resistor R11; one end of the resistor R9 is connected to the output end of the operational amplifier OP2, and the other end is connected to the MCU, and the other end of the resistor R9 is also grounded through a capacitor C6; the capacitor C5 and the resistor R10 are both connected between the positive input end and the output end of the operational amplifier OP2; one end of the capacitor C7 and the resistor R12 is connected to the negative input end of the operational amplifier OP2, and the other end is grounded.

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