CN110460272A - High-power permanent magnet synchronous motor energy discharge device and control method - Google Patents

Abstract

The invention discloses an energy discharge device for a high-power permanent magnet synchronous motor, which is composed of an inverter module, an energy discharge module, a bus voltage detection module, a three-phase line voltage detection module, a controller, and a high-power permanent magnet synchronous motor. Composition, the residual energy is discharged through the energy discharge module when the permanent magnet synchronous motor stops. The invention realizes the energy discharge of the high-power permanent magnet synchronous motor and the control of the discharge process, the transformation of the original circuit is simple, the cost is low, the flexibility of the energy discharge process is realized, the bus voltage is stabilized, and the damage to the operating system is prevented.

Description

High-power permanent magnet synchronous motor energy discharge device and control method

technical field

The invention belongs to the technical field of permanent magnet synchronous motor control, and in particular relates to an energy discharge device and a control method of a high-power permanent magnet synchronous motor.

Background technique

For high-power motors with a power greater than 2000W, when the variable-frequency speed-regulating AC motor drives the load actuator to run in the variable-frequency braking state, due to the existence of load inertia, the rotor speed of the AC motor will be greater than its synchronous speed. It is equivalent to an asynchronous generator and is in the state of regenerative power generation. The braking energy generated by the motor is fed back to the DC bus side of the inverter through the inverter in the inverter, and the rectifier of the inverter usually uses an uncontrollable rectifier diode. Since the diode is characterized by one-way conduction, the braking energy If no measures are taken to feed back to the inverter bus, it will not be able to transfer and release, and then it will continue to accumulate, and the DC bus voltage of the inverter will continue to rise, eventually causing the inverter to skip voltage protection due to the high DC bus voltage, endangering the AC motor The normal operation of the frequency conversion speed control system may even directly damage the frequency converter. In order to avoid the overvoltage fault of the frequency converter, the power electronic switching tube and the braking resistor are usually used together. The energy is consumed on the set braking resistor, and the braking energy is absorbed and consumed by the method of resistance heating, so as to prevent the braking energy of the load side from feeding back to the DC bus side and causing the voltage increase of the DC grid side. In this way, the DC bus side voltage is maintained within a certain set value range, so that the AC motor frequency conversion speed control system can operate safely and stably.

Although the above absorption method can effectively deal with the energy generated by motor braking, there is a disadvantage in this energy consumption method. The heating of the braking resistor will easily cause the temperature rise of the surrounding environment, which will affect the safe operation of the inverter. The energy consumption of the additional heat dissipation link cannot be underestimated.

In summary, it is particularly important to propose an energy discharge device and control method for high-power permanent magnet synchronous motors.

Contents of the invention

The invention discloses an energy discharge device for a high-power permanent magnet synchronous motor, which is characterized in that it consists of an inverter module, an energy discharge module, a bus voltage detection module, a three-phase line voltage detection module, a controller and a high-power permanent magnet Synchronous motors are connected to each other. The invention also discloses an energy discharge control method for a high-power permanent magnet synchronous motor. Two energy discharge modules controlled by a controller work when the high-power permanent magnet synchronous motor stops suddenly, so as to stabilize the bus voltage and prevent damage to the operating system. cause damage.

In order to achieve the above object, the technical solution adopted by the high-power permanent magnet synchronous motor energy discharge device of the present invention is:

An energy discharge device for a high-power permanent magnet synchronous motor, characterized in that it includes: an inverter module, a first energy discharge module, a second energy discharge module, a bus voltage detection module, a three-phase line voltage detection module, a control device;

The inverter module is respectively connected with the controller and the high-power permanent magnet synchronous motor circuit, and the inverter module is used to generate a three-phase voltage for running the high-power permanent magnet synchronous motor;

The first energy discharge module is respectively connected to the inverter module and the controller circuit, and the first energy discharge module releases the energy generated when the high-power permanent magnet synchronous motor brakes based on the signal of the controller ;

The second energy discharge module is respectively connected with the controller, the three-phase line voltage detection module and the high-power permanent magnet synchronous motor circuit, and the second energy discharge module releases high power based on the signal of the controller Energy that cannot be released by the first energy release module generated when the permanent magnet synchronous motor brakes;

The bus voltage detection module is connected to the controller circuit, and the bus voltage detection module is used to collect the bus voltage;

The three-phase line voltage detection module is connected to the controller circuit, and the three-phase line voltage detection module is used to collect the three-phase line voltage at the access point of the high-power permanent magnet synchronous motor;

The controller is used to control the operation and stop of the high-power permanent magnet synchronous motor, and generate control signals for controlling the first energy discharge module and the second energy discharge module.

Further, the first energy discharge module includes: an insulated gate bipolar transistor IGBT7 and a resistor R1; the gate of the insulated gate bipolar transistor IGBT7 is connected to the controller circuit, and the insulated gate bipolar transistor IGBT7 The collector of the polar transistor IGBT7 is connected to one end of the resistor R1, and the emitter of the insulated gate bipolar transistor IGBT7 and the other end of the resistor R1 are connected to the input of the inverter module.

Further, the second energy discharge module includes: an insulated gate bipolar transistor IGBT8, an insulated gate bipolar transistor IGBT9, an insulated gate bipolar transistor IGBT10, a resistor R2, a resistor R3, and a resistor R4; The collector of the gate bipolar transistor IGBT8, the collector of the insulated gate bipolar transistor IGBT9, and the collector of the insulated gate bipolar transistor IGBT10 are respectively connected to the three-phase line circuit of the high-power permanent magnet synchronous motor; the insulated gate The gate of the bipolar transistor IGBT8, the gate of the insulated gate bipolar transistor IGBT9, and the gate of the insulated gate bipolar transistor IGBT10 are connected to the controller circuit; the emitter of the insulated gate bipolar transistor IGBT8 It is connected to one end of the resistor R2, the emitter of the insulated gate bipolar transistor IGBT9 is connected to one end of the resistor R3, and the emitter of the insulated gate bipolar transistor IGBT10 is connected to one end of the resistor R4; The other ends of the resistors R2, R3 and R4 are grounded.

Further, the controller includes a first PWM wave output port, the first energy discharge module is connected to the first PWM wave output port circuit, and the first energy discharge module is controlled by the first PWM wave The PWM wave output from the output port controls on-off.

Further, the controller also includes a second PWM wave output port, a third PWM wave output port, and a fourth PWM wave output port, and the second energy discharge module is connected to the second PWM wave output port, the fourth PWM wave output port, and the second PWM wave output port respectively. The three PWM wave output ports and the fourth PWM wave output port are connected to the circuit, and the second energy discharge module is respectively composed of the PWM wave output from the second PWM wave output port, the PWM wave output from the third PWM wave output port, and The PWM wave output from the fourth PWM wave output port controls on-off.

The present invention also provides a control method of a high-power permanent magnet synchronous motor energy discharge device based on the high-power permanent magnet synchronous motor energy discharge device, which is characterized in that, after the high-power permanent magnet synchronous motor stops suddenly, the busbar The energy discharge process when the voltage continues to rise and the energy discharge process to stop when the bus voltage continues to drop, the specific steps of the energy discharge process are as follows:

Step ₁ : When the bus voltage is higher than the threshold U1, the controller gradually increases the duty cycle of the PWM wave output by the first PWM wave output port, and controls the first energy discharge module to perform energy discharge through the PWM wave;

Step 2: Determine whether the bus voltage continues to rise:

When the bus voltage continues to increase and is higher than the threshold U2, the controller gradually increases the PWM wave output from the _second PWM wave output port, the PWM wave output from the third PWM wave output port, and the PWM wave output from the fourth PWM wave output port The duty cycle is controlled by three PWM waves to control the second energy discharge module to start working, and the first energy discharge module and the second energy discharge module perform energy discharge at the same time until the bus voltage begins to drop and stop the energy discharge process;

When the bus voltage starts to drop, the process of stopping the energy discharge is executed;

The process of stopping energy release is as follows:

When the bus voltage starts to drop from higher _than the threshold U2, the controller gradually reduces the PWM wave output from the first PWM wave output port, the PWM wave output from the second PWM wave output port, and the PWM wave output from the third PWM wave output port The duty cycle until the bus voltage is lower than the threshold U ₁ , the controller makes the PWM wave output from the first PWM wave output port, the PWM wave output from the second PWM wave output port, the PWM wave output from the third PWM wave output port and the PWM wave output from the third PWM wave output port The duty cycle of the PWM waves output by the four PWM wave output ports is zero, stop the work of the first energy discharge module and the second energy discharge module, and complete the entire discharge control process;

When the bus voltage starts to drop from being higher than the threshold U ₁ and lower than the threshold U ₂ , the controller gradually reduces the duty cycle of the PWM wave output from the first PWM wave output port until the bus voltage is lower than the threshold U ₁ , and the controller makes the second The duty cycle of the PWM wave output by a PWM wave output port is zero, and the first energy discharge module is stopped to complete the entire discharge control process.

Further, the controller gradually increases the PWM wave output from the first PWM wave output port, the PWM wave output from the second PWM wave output port, the PWM wave output from the third PWM wave output port, and the PWM wave output from the fourth PWM wave output port The duty cycle until the duty cycle equals 50%.

Further, the threshold U1 is _1.2 times the rated voltage of the high _- power permanent magnet synchronous motor, and the threshold U2 is 1.3 times the rated voltage of the high-power permanent magnet synchronous motor.

Compared with the prior art, the advantages and beneficial effects of the technical solution of the present invention are mainly:

1. By adding a discharge resistor on the power supply side and the three-phase winding of the permanent magnet synchronous motor, and connecting the insulated gate bipolar transistor in series with the discharge resistor, the energy discharge and discharge process control of the high-power permanent magnet synchronous motor is realized. , the transformation of the original circuit is simple and the cost is low; compared with the traditional circuit, the device of the present invention has two discharge modules, and has stronger selectivity in energy discharge.

2. Through the cooperation of the first energy discharge module and the second energy discharge module, the insulated gate bipolar transistor is turned on by PWM to realize the flexibility of the energy discharge process, so that the discharge resistor in any one of the modules Not dangerous due to overheating.

3. By collecting the bus voltage and taking the rated voltage of the high-power permanent magnet synchronous motor as the standard preset threshold value, the threshold value is used as the standard for starting the first energy discharge module and the second energy discharge module and PWM conduction duty cycle adjustment Based on the basis, the first energy release module and the first energy release module perform complementary work, stabilize the bus voltage, and prevent damage to the operating system.

Description of drawings

Fig. 1 is a schematic structural diagram of an energy discharge device for a high-power permanent magnet synchronous motor according to a specific embodiment of the present invention.

Detailed ways

The energy discharge device and control method for a high-power permanent magnet synchronous motor of the present invention will be further described in detail below in conjunction with accompanying drawing 1 .

An energy discharge device for a high-power permanent magnet synchronous motor, comprising: an inverter module 1, a bridge rectifier, a bus capacitor C1, a first energy discharge module 2, a second energy discharge module 3, a bus voltage detection module 4, Three-phase line voltage detection module 5, controller 6;

The inverter module 1 includes: IGBT1, IGBT2, IGBT3, IGBT4, IGBT5 and IGBT Pole type transistor IGBT6;

Wherein the first energy discharge module 2 includes: an insulated gate bipolar transistor IGBT7, a resistor R1;

The second energy discharge module 3 includes: IGBT8, IGBT9, IGBT10, resistor R2, resistor R3 and resistor R4;

Wherein the controller includes: a first PWM wave output port P1, a second PWM wave output port P2, a third PWM wave output port P3 and a fourth PWM wave output port P4;

As shown in Figure 1, one side of the bridge rectifier is connected to the positive pole of the bus capacitor C1, the collector of the insulated gate bipolar transistor IGBT1, the collector of the insulated gate bipolar transistor IGBT3, and the collector of the insulated gate bipolar transistor IGBT5. The collector is connected to the emitter of the insulated gate bipolar transistor IGBT7, and the other side of the bridge rectifier is respectively connected to the negative pole of the bus capacitor C1, the emitter of the insulated gate bipolar transistor IGBT2, and the emitter of the insulated gate bipolar transistor IGBT4 pole, the emitter of the insulated gate bipolar transistor IGBT6 and one end of the resistor R1 are connected, the emitter of the insulated gate bipolar transistor IGBT1 is connected to the collector of the insulated gate bipolar transistor IGBT2, and the A-phase winding of the permanent magnet synchronous motor And the collector of the insulated gate bipolar transistor IGBT8 is connected, the emitter of the insulated gate bipolar transistor IGBT3 is connected with the collector of the insulated gate bipolar transistor IGBT4, the B-phase winding of the permanent magnet synchronous motor and the insulated gate bipolar transistor The collector of IGBT9 is connected, the emitter of insulated gate bipolar transistor IGBT5 is respectively connected with the collector of insulated gate bipolar transistor IGBT6, the C-phase winding of permanent magnet synchronous motor, and the collector of insulated gate bipolar transistor IGBT10. The collector of the gate bipolar transistor IGBT7 is connected to the other end of the resistor R1, the emitter of the insulated gate bipolar transistor IGBT8 is connected to one end of the resistor R2, and the emitter of the edge-gate bipolar transistor IGBT9 is connected to one end of the resistor R3 , the emitter of the edge-gate bipolar transistor IGBT10 is connected to one end of the resistor R4, the other end of the resistor R2, the other end of the resistor R3 and the other end of the resistor R4 are all connected to the ground, and the bus voltage detection module 4 is connected to the bridge rectifier Both sides and the output terminal of the bus voltage detection module 4 are connected to the controller 6, the three-phase line voltage detection module 5 is respectively connected to the collectors of the insulated gate bipolar transistors IGBT8-IGBT10, and the output of the three-phase line voltage detection module 5 and The controller 6 is connected, the gates of the insulated gate bipolar transistors IGBT1~IGBT6 are connected to the controller 6, and the gates of the insulated gate bipolar transistors IGBT7~IGBT10 are sequentially connected to the ports P1, P2, P3, Port P4 is connected.

Among them, the bridge rectifier rectifies the alternating current into direct current, the capacitor C1 filters the converted direct current, the inverter module 1 is used to generate the three-phase voltage for running the high-power permanent magnet synchronous motor; the first energy discharge module is used for Release the energy generated when the high-power permanent magnet synchronous motor brakes; the second energy release module is used to release the energy that cannot be released by the first energy release module when the high-power permanent magnet synchronous motor brakes; the bus voltage detection module 4 Used to collect the bus voltage; the three-phase line voltage detection module 5 is used to collect the three-phase line voltage at the access point of the high-power permanent magnet synchronous motor; the controller 6 is used to control the operation and stop of the high-power permanent magnet synchronous motor Control signals of an energy discharge module and a second energy discharge module, and process bus voltage signals and three-phase line voltage signals.

The energy generated in the braking process is converted into the heat of the discharge resistors R1, R2, R3 and R4 to realize energy-consuming braking. The braking resistors of 200W are selected for the resistors R1, R2, R3 and R4 to meet the The braking energy demand of the high-power permanent magnet synchronous motor that consumes more than 2000W will not generate a lot of heat and prevent the braking resistor from overloading.

The control method of the high-power permanent magnet synchronous motor energy discharge device is as follows:

After the high-power permanent magnet synchronous motor stops suddenly, the energy discharge process when the bus voltage continues to rise and the energy discharge process when the bus voltage continues to drop, the specific steps of the energy discharge process are as follows:

Step S1: When the bus voltage is higher _than the threshold U1, the controller gradually increases the duty cycle of the PWM wave output by the first PWM wave output port, and controls the first energy discharge module to discharge energy through the PWM wave;

Step S2: Determine whether the bus voltage continues to rise. At this time, the bus voltage may continue to rise or start to fall:

When the bus voltage continues to increase and is higher than the threshold U2, the controller gradually increases the PWM wave output from the _second PWM wave output port, the PWM wave output from the third PWM wave output port, and the PWM wave output from the fourth PWM wave output port The duty cycle is controlled by three PWM waves to control the second energy discharge module to start working, and the first energy discharge module and the second energy discharge module perform energy discharge at the same time until the bus voltage begins to drop and stop the energy discharge process;

When the bus voltage starts to drop, the process of stopping the energy discharge is executed;

Since the initial drop point of the bus voltage is different, when the drop point is higher than U ₂ , more energy needs to be discharged, and two discharge modules need to be released together; when the drop point is between U ₂ and U ₁ , the energy needs to be discharged If there is not much energy released, only one discharge module is required to work. The process of stopping energy discharge is as follows:

When the bus voltage starts to drop from higher _than the threshold U2, the controller gradually reduces the PWM wave output from the first PWM wave output port, the PWM wave output from the second PWM wave output port, and the PWM wave output from the third PWM wave output port The duty cycle until the bus voltage is lower than the threshold U ₁ , the controller makes the PWM wave output from the first PWM wave output port, the PWM wave output from the second PWM wave output port, the PWM wave output from the third PWM wave output port and the PWM wave output from the third PWM wave output port The duty cycle of the PWM waves output by the four PWM wave output ports is zero, stop the work of the first energy discharge module and the second energy discharge module, and complete the entire discharge control process;

When the bus voltage starts to drop from being higher than the threshold U ₁ and lower than the threshold U ₂ , the controller gradually reduces the duty cycle of the PWM wave output from the first PWM wave output port until the bus voltage is lower than the threshold U ₁ , and the controller makes the second The duty cycle of the PWM wave output by a PWM wave output port is zero, and the first energy discharge module is stopped to complete the entire discharge control process.

Among them, the preferred threshold value U1 is _1.2 times the rated voltage of the high-power permanent magnet synchronous motor, which can not only ensure the energy discharge of the high-power permanent magnet synchronous motor but also protect the components in the first energy discharge module from being damaged burn out.

Among them, the preferred threshold value U2 is 1.3 times of the rated voltage of the high _- power permanent magnet synchronous motor, which can not only ensure the discharge of the energy of the high-power permanent magnet synchronous motor but also protect the components in the second energy discharge module from being damaged burn out.

Among them, it is preferable that the duty cycle of PWM1, PWM2, PWM3, and PWM4 not exceed 50% when gradually increasing, which can not only ensure the energy discharge of the high-power permanent magnet synchronous motor, but also protect the discharge resistor and the bipolar type of the insulation gate. The transistor IGBT will not be burned out, which improves the stability of the system.

The above embodiments are only to illustrate the technical ideas of the present invention, and can not limit the protection scope of the present invention with this. All technical ideas proposed in accordance with the present invention, any changes made on the basis of technical solutions, all fall within the protection scope of the present invention. Inside.

Claims (8)

1. a kind of high power permanent magnet synchronous motor energy bleeder characterized by comprising inverter module, the first energy are let out Amplification module, the second energy are released module, busbar voltage detection module, three-phase line voltage detection module, controller；

The inverter module is respectively with controller and high power permanent magnet synchronous motor circuit connection, and the inverter module is for producing The raw three-phase voltage for operating high power permanent magnet synchronous motor；

First energy module of releasing is connect with the inverter module and controller circuitry respectively, and first energy is released Module discharges the energy generated when high power permanent magnet synchronous motor braking based on the control signal of the controller；

Second energy module of releasing is synchronous with the controller, three-phase line voltage detection module and high-power permanent magnet respectively Motor circuit connection, second energy is released, and that high-power permanent magnet is discharged based on the control signal of the controller is synchronous for module First energy generated when motor braking is released the energy that module can not discharge；

The busbar voltage detection module is connect with the controller circuitry, and the busbar voltage detection module is for acquiring bus Voltage；

The three-phase line voltage detection module is connect with the controller circuitry, and the three-phase line voltage detection module is for acquiring Three-phase line voltage at high power permanent magnet synchronous motor access；

The controller generates control first energy and lets out for controlling high power permanent magnet synchronous motor operating and stopping Amplification module and second energy are released the control signal of module.

2. high power permanent magnet synchronous motor energy bleeder as described in claim 1, which is characterized in that first energy It include: insulated gate bipolar transistor IGBT 7, resistance R1 in module of releasing；The door of the insulated gate bipolar transistor IGBT 7 Pole is connect with the controller circuitry, the collector of the insulated gate bipolar transistor IGBT 7 and the one end resistance R1 electricity Road connection, the emitter of the insulated gate bipolar transistor IGBT 7 and the other end of resistance R1 access the inverter module Input terminal.

3. high power permanent magnet synchronous motor energy bleeder as described in claim 1, which is characterized in that second energy It include: insulated gate bipolar transistor IGBT 8, insulated gate bipolar transistor IGBT 9, insulated gate bipolar crystalline substance in module of releasing Body pipe IGBT10, resistance R2, resistance R3 and resistance R4；Collector, the insulated gate of the insulated gate bipolar transistor IGBT 8 Collector, the collector of insulated gate bipolar transistor IGBT 10 of bipolar transistor IGBT 9 are same with high-power permanent magnet respectively Walk the triple line circuit connection of motor；Gate pole, the insulated gate bipolar transistor of the insulated gate bipolar transistor IGBT 8 The gate pole of IGBT9, the gate pole of insulated gate bipolar transistor IGBT 10 are connect with the controller circuitry；The insulated gate bipolar The emitter of transistor npn npn IGBT8 and one end circuit connection of resistance R2, the transmitting of the insulated gate bipolar transistor IGBT 9 One end circuit connection of pole and resistance R3, the emitter of the insulated gate bipolar transistor IGBT 10 and one end electricity of resistance R4 Road connection；The other end ground connection of the other end of the resistance R2, the other end of resistance R3, resistance R4.

4. high power permanent magnet synchronous motor energy bleeder as described in claim 1, which is characterized in that the controller packet Include the first PWM wave output port, first energy module of releasing is connect with the first PWM wave output port circuit, described The first energy PWM wave that module is exported by the first PWM wave output port of releasing controls on-off.

5. high power permanent magnet synchronous motor energy bleeder as described in claim 1 or 4, which is characterized in that the control Device further includes the second PWM wave output port, third PWM wave output port and the 4th PWM wave output port, second energy Module of releasing is electric with the second PWM wave output port, third PWM wave output port and the 4th PWM wave output port respectively Road connection, second energy are released PWM wave, third PWM wave of the module respectively by exporting from the second PWM wave output port The PWM wave of output port output and the PWM wave of the 4th PWM wave output port output control on-off.

6. a kind of control method of high power permanent magnet synchronous motor energy bleeder, which is characterized in that be included in it is high-power forever After magnetic-synchro motor emergency stop, busbar voltage letting out in lasting raising can process and the stopping when busbar voltage continues to decline Energy process is let out, specific step is as follows wherein letting out energy process:

Step 1: when busbar voltage is higher than threshold value U₁When, controller gradually increases the PWM wave of the first PWM wave output port output Duty ratio, by PWM wave control the first energy release module carry out energy release；

Step 2: judge whether busbar voltage continues to increase:

When busbar voltage continues to increase and is higher than threshold value U₂When, controller gradually increases the PWM of the second PWM wave output port output The duty ratio of the PWM wave of wave, the PWM wave of third PWM wave output port output and the output of the 4th PWM wave output port, respectively It controls the second energy module of releasing by three PWM waves to start to work, module that the first energy releases module and the second energy is released Energy is carried out simultaneously to release until busbar voltage begins to decline execution and stops letting out energy process；

When busbar voltage is begun to decline, executes and stop letting out energy process；

It is specific as follows that energy process is let out in stopping:

When busbar voltage is from higher than threshold value U₂When beginning to decline, controller is gradually reduced the PWM of the first PWM wave output port output The duty ratio of the PWM wave of wave, the PWM wave of the second PWM wave output port output and the output of third PWM wave output port is until female Line voltage is lower than threshold value U₁, controller make the first PWM wave output port export PWM wave, the second PWM wave output port output The duty ratio of PWM wave of PWM wave, the PWM wave of third PWM wave output port output and the output of the 4th PWM wave output port is Zero, stop release module, the second energy of the first energy and release module work, completes entirely to release control process；

When busbar voltage is from higher than threshold value U₁And it is lower than threshold value U₂When beginning to decline, controller gradually decreases the first PWM wave output end The duty ratio of the PWM wave of mouth output is until busbar voltage is lower than threshold value U₁, controller make the first PWM wave output port export The duty ratio of PWM wave is zero, stops the first energy and releases module work, completes entirely to release control process.

7. the control method of high power permanent magnet synchronous motor energy bleeder as claimed in claim 6, which is characterized in that control Device processed gradually increases the PWM wave of the first PWM wave output port output, the PWM wave of the second PWM wave output port output, the 3rd PWM The duty ratio of the PWM wave of the PWM wave and the 4th PWM wave output port output of wave output terminal mouth output is until duty ratio is equal to 50%.

8. the control method of high power permanent magnet synchronous motor energy bleeder as claimed in claims 6 or 7, feature exist In the threshold values U₁It is 1.2 times of high power permanent magnet synchronous motor voltage rating, the threshold values U₂Electricity is synchronized for high-power permanent magnet 1.3 times of machine voltage rating.