CN201656898U - AC asynchronous motor vector controller - Google Patents

Abstract

Disclosed is an AC asynchronous motor vector controller, which comprises a control chip, a driving circuit, a three-phase inverter circuit, a Hall sensor, and an amplifying and filtering circuit. The vector controller is characterized in that: a PWM output hardware interlocking circuit is connected between the control chip and the driving circuit; and an IGBT over-current signal of the driving circuit is fed back to the PWM output hardware interlocking circuit. An output end of the amplifying and filtering circuit of a current sampling circuit is connected with a stator over-current signal generating circuit in parallel and feeds back a stator over-current signal to the PWM output hardware interlocking circuit. A temperature sensor is arranged at the bottom of an IGBT module, a signal thereof is input to an A/D port of the control chip, and a universal input/output port of the control chip controls the operation of a radiating fan. The AC asynchronous motor vector controller can effectively realize under-voltage protection on the IGBT module and overcurrent protection on current, and realizes the IGBT soft turn-off and protection function of the motor stator current overcurrent.

Description

Vector controller of alternating current asynchronous motor

Technical field

The utility model belongs to the power set field, particularly the protection of Electric Vehicle's Alternating asynchronous motor vector converter governing system IGBT module.

Technical background

The vector controller of alternating current asynchronous motor chief component is: these three parts of motor, inverter and battery pack.The internal structure of IGBT module is an inverter bridge, i.e. the core of inverter, and the length in its useful life directly has influence on the useful life of entire controller, and the expense of IGBT module accounts for 2/3rds of inverter.

Following difficult point is arranged when design IGBT drive circuit:

When 1) working long hours, can send a large amount of heats, and cause that IGBT crosses cause thermal damage owing to the IGBT module.

2) the big young pathbreaker of grid positive drive voltage produces material impact to circuit performance, must correctly select.When positive drive voltage increased, the conducting resistance of IGBT descended, and turn-on consumption is reduced; But if its short circuit current IC increases with UGE during the excessive then load short circuits of positive drive voltage, may make IGBT latching effect occur, cause the gate inefficacy, thereby cause the damage of IGBT; If the too small meeting of positive drive voltage makes IGBT withdraw from the saturation conduction district and enters the linear amplification zone, make IGBT cross cause thermal damage.

3) in general, IGBT is the maximum rated current that can bear 2 times in 10 μ S, but often bear overcurrent and can make the device premature aging, so during the IGBT overcurrent, adopt soft cut-off method to make grid voltage in the time of 2 μ S-5 μ S, reduce to no-voltage, because instantaneous blockade grid voltage can make di/dt very big, produce very high peak voltage at the IGBT two ends, very easily damage IGBT.

4) when frequency converter turns round, when overcurrent appears in the motor stator electric current, not only can influence the useful life of motor or even motor is burnt out, also will be impacted the useful life of IGBT module.

Therefore, the driving of IGBT and protective circuit are the difficult point and the emphasis of circuit design.For addressing this problem, IGBT producer develops numerous IGBT driver modules both at home and abroad.Yet, the still soft shutoff of the series of modules low price of domestic most of producers, overcurrent and under-voltage defencive function are incomplete; And external series of modules is multiple functional, and often price is high.And the HCPL-316J gate-drive optocoupler of using Agilent company is combined as a kind of reliable IGBT drive circuit in conjunction with TMS320LF2407A; for the reliably working of drive circuit provides protection; soft shutoff, overcurrent and under-voltage defencive function are complete, and less expensive.

Summary of the invention:

The purpose of this utility model is to propose a kind of realization to the under-voltage protection of IGBT module, overcurrent protection, realizes the technical scheme of the defencive function of soft shutoff of IGBT and motor stator overcurrent.

The utility model is achieved through the following technical solutions.Referring to accompanying drawing 1

Between control chip (TMS320LF2407A) and drive circuit, insert PWM output hardware interlock circuit (accompanying drawing 4), and the IGBT over-current signal of drive circuit is fed back to PWM output hardware interlock circuit; At the output of the amplification filtering circuit of current sampling circuit and connect the stator current over-current signal and produce circuit (accompanying drawing 5), and the stator current over-current signal is fed back to PWM output hardware interlock circuit; PWM output hardware interlock circuit produces a guard signal again, inputs to the PDPINTB port of control chip.Add a temperature sensor in the bottom of IGBT module, its signal inputs to the A/D port of control chip, and is controlled the running of radiator fan by the universal input and output port of control chip.

PWM output hardware interlock circuit described in the utility model (referring to shown in Figure 4) is made up of chip GAL16V8D, resistance R 1, R2, R3, capacitor C 1.The pin one of chip connects R2, R1 ground connection more successively, and R2, R1 link are connected to the PDPINTB port of control chip (TMS320LF2407A); The pin two of chip is connected to the 3.3V power supply by R3, and its pin one 0,11 connects back ground connection, and pin two 0 connects the 5V power supply, and by C1 ground connection, pin one is connected with pin one 9.

Stator current over-current signal described in the utility model produces circuit (shown in accompanying drawing 5) by slide rheostat R1, R2, and voltage comparator U1A, U1B form.The series connection of two slide rheostats, series connection back one termination 3.3V power supply, other end ground connection; Slide rheostat R2 output connects comparator U1A positive input, and slide rheostat R1 output connects comparator U1B negative input; The input of U1A negative sense is in parallel with the input of U1B forward, and is connected with stator current signal VI behind process amplification filtering and the voltage bias; U1A and U1B output-parallel.

The utility model is realized triple protection to the IGBT module:

(1) IGBT module overtemperature protection when working long hours owing to the IGBT module, can produce a large amount of heats; damage for preventing that IGBT is overheated, add a temperature sensor in the bottom of IGBT module, change by real-time detected temperatures; control the running of radiator fan, with protection IGBT module.

(2) under-voltage protection of IGBT module and overcurrent protection, driving and the protective circuit of the IGBT that the HCPL-316J of the utility model employing Agilent company constitutes, driving, under-voltage protection, the overcurrent protection finished the IGBT module also realize the soft shutoff of IGBT module.(accompanying drawing 3)

(3) when frequency converter turns round, when overcurrent appears in the motor stator electric current, not only can influence the useful life of motor or even motor is burnt out, and to impacting the useful life of IGBT module.When the stator current overcurrent, the stator current over-current signal produces circuit will produce the effective alarm signal of a low level; And when IGBT module overcurrent, HCPL-316J also will produce an overcurrent protection signal.After two signals are sent into PWM output hardware interlock circuit operation, send into TMS320LF2407A task manager external interrupt pin, finish triple protection of the present utility model.

TMS320LF2407A task manager external interrupt program circuit (as shown in Figure 6) is: have no progeny in entering keep the scene intact → close PWM output → inquiry failure mode → shielding PDPINT interruption → recovery on-the-spot → withdraw from interruption.

Control chip (TMS320LF2407A) to the control flow (as shown in Figure 2) of the bottom temp of IGBT module is: the bottom temp to the IGBT module detects, and when being higher than 48 ℃, opens cooling fan; When being lower than 38 ℃, close cooling fan; Report to the police when being higher than 70 ℃, the output torque reduces by half; Temperature continues to rise and blocks controller output when being higher than 80 ℃ in 5 seconds; Temperature dropped to 65 ℃ after torque reduced by half, and system restoration is normal after 5 seconds.

Description of drawings

Fig. 1 is the vector controller structural representation.

Fig. 2 is an IGBT module temperature protection flow chart.

Fig. 3 is an IGBT module drive circuit diagram.

Fig. 4 is PWM output hardware interlock circuit diagram.

Fig. 5 produces circuit diagram for the stator current over-current signal.

Fig. 6 is a TMS320LF2407A task manager external interrupt flow chart.

Embodiment

Further specify the utility model below in conjunction with the drawings and specific embodiments.

Embodiment.

Present embodiment as shown in Figure 1, controller comprises that control chip TMS320LF2407A, PWM output hardware interlock circuit, drive circuit, three-phase inverting circuit, motor, Hall element, amplification filtering circuit, stator current over-current signal produce circuit, temperature sensor, fan etc.Control chip TMS320LF2407A is connected with PWM output hardware interlock circuit, drive circuit, three-phase inverting circuit, motor successively by the PWM port; Hall element is by after extracting the motor stator electric current, is connected to the A/D port of control chip TMS320LF2407A by the amplification filtering circuit, and the amplification filtering circuit produces circuit by the stator current over-current signal simultaneously and is connected to PWM output hardware interlock circuit; Temperature sensor places its signal of bottom of IGBT module to input to the A/D port of control chip, and is controlled the running of radiator fan by the universal input and output port of control chip.

Ignition signal control three-phase inverting circuit starts, start the back controller the given signal of throttle will be resolved into two vertically and independently direct current signal excitation current component and torque components mutually, calculate synthetic 6 road pwm signals control three-phase inverting circuit by control chip TMS320LF2407A then.Current feedback signal is sent to controller together with feedback speed signal after coordinate transform, dc control signal is revised.

Temperature sensor passes to control chip with the bottom temp of IGBT module, and controller is done following processing: when being higher than 48 ℃, open cooling fan; When being lower than 38 ℃, close cooling fan; Report to the police when being higher than 70 ℃, will export torque and reduce by half; Temperature continues to rise and blocks controller output when being higher than 80 ℃ in 5 seconds; Temperature dropped to 65 ℃ after torque reduced by half, and system restoration is normal after 5 seconds.Flow chart as shown in Figure 2.

Driving and the protective circuit of the IGBT that the HCPL-316J of the drive circuit employing Agilent company of present embodiment constitutes are to finish driving, under-voltage protection, the overcurrent protection to the IGBT module and to realize the soft shutoff of IGBT module.

Chip for driving HCPL-316J inner integrated collector emitter voltage undersaturation testing circuit and malfunction feedback circuit are for the reliably working of drive circuit provides protection.Produce pwm control signal by control chip TMS320LF2407A, send into HCPL-316J through isolation amplify after, two metal-oxide-semiconductor break-makes of output control, the generation of opening required positive voltage and turn-offing required negative voltage by two metal-oxide-semiconductor break-makes control IGBT.Simultaneously, HCPL-316J is also integrated two kinds of defencive functions, under-voltage protection and overcurrent protection, and also have soft turn-off function.When overcurrent protection, output drive signal is blocked, export an effective alarm signal of low level.It is normal that under-voltage protection can recover after fault disappears automatically, and recovering overcurrent protection then needs HCPL-316J is resetted again.Because the existence that various spikes disturb influences the operate as normal of Switching Power Supply for avoiding frequent protection, has set up the blind area.In time of delay, if over-current signal disappears, then driver thinks that this overcurrent does not belong to real short circuit, need not to interrupt the operate as normal of power supply, thereby recovers original drive level.If over-current signal exists, then will enter the process of soft shutoff.After soft shutoff began, driver blocked the input pwm signal, even pwm signal becomes low level, also can immediately output not moved to normal negative level, then continues soft turn off process.Present embodiment is arranged on 6 μ S time of delay.

HCPL-316J pin 1, pin 6 connect the FAULT signal that 2407 pins come out, and link to each other with ground through capacitor C 2; Pin 2 connects the VH signal that 2407 pins come out through resistance R 6; Pin 3 connects+the 5V power supply; Pin 4, pin 8 ground connection; Pin 5 links to each other with+5V power supply through resistance R 5, keeps high level, and is continuous by the contactor of outside; Pin 9, pin 10 links to each other with-9V power supply through diode D3; Pin 11 all links to each other with+15V power supply through diode D2; Pin 12, pin 13 link to each other with the control pin 2 of Q1, Q2; Pin 14 links to each other with the IGBT collector electrode with resistance R 1 through diode D1; Pin 16 and+15V and-9V link to each other commonly, as reference voltage; As shown in Figure 3.

When VH was input as low level, HCPL-316J pin 11 was output as high level, made the Q1 conducting, Q2 by, UPOUT is output as+15V, the conducting of IGBT module; When VH was input as high level, HCPL-316J pin 11 was output as low level, the Q2 conducting, and Q1 ends, and UPOUT is output as-9V, the IGBT module shuts down.When IGBT was under-voltage, when promptly voltage was less than 13V on 13 pins, under-voltage locking activated, and output keeps low level always, blocks the IGBT module, misleaded and burnt in order to avoid depress the IGBT module at low excessively grid radio; When voltage is greater than 13V on 13 pins, withdraw from protection.When overcurrent takes place during in conducting the IGBT module; because the inherent characteristic of IGBT module; Vce sharply raises; surpass the Uce protection voltage 7V of IGBT module, promptly the P1 terminal voltage surpasses 7V, then HCPL-316J output low level; turn-off the IGBT module; while FAULT pin output low level alarm signal, the FAULT pin keeps low level signal always, resets again up to HCPL-316J.

When over current fault or motor stator overcurrent appear in the IGBT module, can produce the two-way alarm signal respectively, during IGBT module overcurrent, chip for driving HCPL-316J produces the effective alarm signal of low level, and send into the GAL16V8D pin 2 that PWM exports the hardware interlock circuit, as shown in Figure 4; During the stator current overcurrent, stator current is during greater than V1, and comparator U1A is output as low level; When stator current during less than V2, when comparator U1B is output as low level, as shown in Figure 5.When stator current low level signal of comparator output during greater than V1 or less than V2, be the stator current absolute value greater than certain value after, comparator can be exported a low level signal comparator circuit, also can provide an effective alarm signal of low level, send into GAL16V8D pin 3, as shown in Figure 4.The two-way alarm signal through logical device carry out with the operation after obtain a low level signal; be connected to the power drive protection interrupt pin PDPINTB of TMS320LF2407A task manager B; protection interrupt pin PDPINTB is a low level; TMS320LF2407A blocks PWM output; not destroyed with protection IGBT module; TMS320LF2407A analyzes failure cause; and transmission failure code; then shielding is interrupted; pin PDPINTB is a high level; lift a blockade PWM output of TMS320LF2407A, PWM normally exports, and protection is interrupted flow chart as shown in Figure 6.

Claims (3)

1. vector controller of alternating current asynchronous motor, comprise control chip, drive circuit, three-phase inverting circuit, Hall element, amplification filtering circuit, it is characterized in that between control chip and drive circuit, inserting PWM output hardware interlock circuit, and the IGBT over-current signal of drive circuit is fed back to PWM output hardware interlock circuit; At the output of the amplification filtering circuit of current sampling circuit and connect the stator current over-current signal and produce circuit, and the stator current over-current signal is fed back to PWM output hardware interlock circuit; Add a temperature sensor in the bottom of IGBT module, its signal inputs to the A/D port of control chip, and is controlled the running of radiator fan by the universal input and output port of control chip.

2. controller according to claim 1, it is characterized in that described PWM exports the hardware interlock circuit and is made up of chip GAL16V8D, resistance R 1, R2, R3, capacitor C 1, the pin one of chip connects R2, R1 ground connection more successively, and R2, R1 link are connected to the PDPINTB port of control chip LF2407A; The pin two of chip is connected to the 3.3V power supply by R3, and its pin one 0,11 connects back ground connection, and pin two 0 connects the 5V power supply, and by C1 ground connection, pin one is connected with pin one 9.

3. controller according to claim 1 is characterized in that described stator current over-current signal produces circuit by slide rheostat R1, R2, and voltage comparator U1A, U1B form, the series connection of two slide rheostats, series connection back one termination 3.3V power supply, other end ground connection; Slide rheostat R2 output connects comparator U1A positive input, and slide rheostat R1 output connects comparator U1B negative input; The input of U1A negative sense is in parallel with the input of U1B forward, and is connected with stator current signal VI behind process amplification filtering and the voltage bias; U1A and U1B output-parallel.

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