阅读说明：本技术 一种基于超级电容-能耗电阻的可控再生制动系统及其控制方法 (Controllable regenerative braking system based on super capacitor-energy consumption resistor and control method thereof ) 是由 彭辉 吴美平 卢惠民 肖军浩 徐�明 曾志文 于 2020-04-29 设计创作，主要内容包括：本发明公开了一种基于超级电容-能耗电阻的可控再生制动系统及其控制方法,本发明的系统包括复合控制单元、超级电容、能耗电阻、锂电池供电电路、超级电容供电/制动电路、能耗电阻制动电路及电机驱动桥,电机驱动桥直流侧连接到正负极母线,锂电池供电电路、超级电容供电/制动电路、能耗电阻制动电路均连接到正负极母线,超级电容供电/制动电路包括电容降压桥和电容升压桥,能耗电阻制动电路包括能耗降压桥。本发明能够在基于超级电容的再生制动过程中电机速度可控且制动力矩恒定,使得超级电容可以更好地应用在电机传动系统中,电机制动时的动能能够尽可能多地存储在超级电容中,当电机制动模式发生切换时为无扰切换。(The invention discloses a controllable regenerative braking system based on a super capacitor-energy consumption resistor and a control method thereof. The invention can control the motor speed and keep the braking torque constant in the regenerative braking process based on the super capacitor, so that the super capacitor can be better applied to a motor transmission system, the kinetic energy of the motor during braking can be stored in the super capacitor as much as possible, and undisturbed switching is realized when the motor braking mode is switched.)

1. A controllable regenerative braking system based on a super capacitor-energy consumption resistor is characterized in that: comprises a composite control unit, a super capacitor and an energy consumption resistor R_erLithium battery power supply circuit, super capacitor power supply/braking circuit, energy consumption resistance braking circuit and motor drive axle S_moSaid motor drive bridge S_moThe alternating current side is connected with the motor, the direct current side is connected with the positive and negative buses, the lithium battery power supply circuit is connected with the positive and negative buses, and the super capacitor power supply/braking circuit comprises a capacitor voltage reduction bridge S_ecAnd a capacitor boost bridge S_cThe super capacitor sequentially passes through the capacitor voltage reduction bridge S_ecCapacitor boost bridge S_cConnected to the positive and negative busbars, the energy consumption resistance braking circuit comprises an energy consumption voltage reduction bridge S_erSaid energy consumption resistor R_erBy energy consumption step-down bridge S_erConnected to the positive and negative buses, and the control output end of the composite control unit is connected with the motor drive axle S through the PWM generator and the motor drive axle S respectively_moCapacitor voltage reducing bridge S_ecCapacitor boost bridge S_cEnergy consumption voltage reduction bridge S_erAre connected with each other.

2. The supercapacitor-dissipative resistor-based controllable regenerative braking system according to claim 1, wherein said lithium battery power supply circuit comprises a lithium battery and an inductor L_bThe lithium battery passes through inductor L_bConnected to positive and negative bus bars.

3. The supercapacitor-mer-resistor based controllable regenerative braking system according to claim 1, characterized in that the capacitive buck bridge S_ecCapacitor boost bridge S_cWith a capacitor arranged in parallel therebetween.

4. The supercapacitor-memristor-based controllable regenerative braking system according to claim 1, wherein a capacitor C is arranged in parallel between the positive and negative busbars_L。

5. The method of claim 1The controllable regenerative braking system based on the super capacitor-energy consumption resistor is characterized in that the super capacitor and the capacitor voltage reduction bridge S_ecAn inductor L is connected in series between_ecSaid capacitor step-up bridge S_cAn inductor L is connected in series between the positive bus bar and the negative bus bar_c。

6. A control method of the supercapacitor-energy-consumption-resistor-based controllable regenerative braking system according to any one of claims 1 to 5, characterized by comprising the following steps: when the motor system needs to be started or accelerated, the composite control unit closes the energy consumption voltage reduction bridge S_erAnd turn on the capacitor step-down bridge S_ecCapacitor boost bridge S_cThe output voltage of the super capacitor firstly passes through the capacitor voltage reduction bridge S_ecCapacitor boost bridge S_cStep-up to the lithium battery voltage V_highThen together with the lithium battery power supply circuit through a motor drive bridge S_moA drive motor; when the motor system brakes, the motor system is in a super capacitor braking mode by default and is switched to an energy consumption resistance braking mode when a specified trigger condition is met; wherein, the combined control unit closes the energy consumption voltage reduction bridge S in the super capacitor braking mode_erAnd energy consumption voltage reduction bridge S_erAnd turn on the capacitor boost bridge S_cThe kinetic energy of the motor passes through a capacitive step-up bridge S_cAfter boosting, charging the super capacitor to control the speed of the motor; the composite control unit closes the capacitor voltage reduction bridge S in the energy consumption resistance braking mode_ecAnd a capacitor boost bridge S_cAnd starting the energy consumption voltage reduction bridge S_erThe kinetic energy of the motor passes through a power consumption resistor R_erDissipated to control motor speed.

7. The control method of the supercapacitor-energy-consumption-resistor-based controllable regenerative braking system according to claim 6, wherein the meeting of the specified trigger condition specifically means meeting any one of the following two conditions:

in the above formula, the condition V_busIs the bus voltage of the positive and negative buses, V_thIs a capacitive boost bridge S_cThreshold voltage of V_capIs the voltage of a super capacitor, V_highIs the lithium battery voltage.

8. The control method of the supercapacitor-edr based controllable regenerative braking system according to claim 6, wherein the composite control unit comprises a mode switching controller OMSC, a first active disturbance rejection controller ADRC1 and a second active disturbance rejection controller ADRC2 and a mode switching controller OMSC, which are implemented by software or hardware, the mode switching controller OMSC is used for switching to the edr braking mode when a specified trigger condition is met during braking of the motor system, the first active disturbance rejection controller ADRC1 is used for controlling the motor speed based on the supercapacitor braking mode, and the second active disturbance rejection controller ADRC2 is used for controlling the motor speed based on the edr braking mode.

9. The control method of the supercapacitor-watt-resistor-based controllable regenerative braking system according to claim 6, characterized in that the input of the first active disturbance rejection controller ADRC1 is the motor speed v_bAnd a specified reference velocity v_gThe output is used for controlling a capacitor voltage reduction bridge S through a PWM generator_ec。

10. The control method of the supercapacitor-watt-resistor-based controllable regenerative braking system according to claim 6, characterized in that the input of the second active disturbance rejection controller ADRC2 is the motor speed v_bAnd a specified reference velocity v_gThe output is used for controlling the energy consumption voltage reduction bridge S through the PWM generator_er。

Technical Field

The invention relates to a regenerative braking technology of a motor system of a super capacitor, in particular to a controllable regenerative braking system based on the super capacitor-energy consumption resistor and a control method thereof.

Background

The control problem of the motor speed when the motor driving system recovers the kinetic energy to the super capacitor is worth paying attention. If the motor drive system utilizes super capacitor regenerative braking, the deceleration is very fast when the motor speed is high because of the induced electromotive force V on the bus_busProportional to the motor speed. When V is_busLower than the super capacitor voltage V_capIn time, the kinetic energy of the motor can not be converted into the electric energy of the super capacitor, and the motor can not be braked. This is not allowed in many motor drive applications, such as electric cars, elevators, etc. The dynamic resistor can ensure that the dynamic braking can be carried out when the motor speed is at any value, so that the dynamic resistor can be used for braking when the motor speed is lower. In order to ensure smoothness of the motor drive system during braking, comfort of passengers and the like, it is desirable that when the braking coefficient is fixed, the braking torque for decelerating the motor should be constant, that is, the acceleration of the motor should be a negative value, and the motor should not cause a jitter in the motor speed when switching from the supercapacitor-based braking mode to the resistance-based braking mode.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: the invention can control the speed of a motor and keep the braking torque constant in the regenerative braking process based on the super capacitor, so that the super capacitor can be better applied to a motor transmission system, the kinetic energy of the motor during braking can be stored in the super capacitor as much as possible, and the motor is switched in a non-disturbance mode when the braking mode of the motor is switched.

In order to solve the technical problems, the invention adopts the technical scheme that:

a controllable regenerative braking system based on a super capacitor-energy consumption resistor comprises a composite control unit, a super capacitor and an energy consumption resistor R_erLithium battery power supply circuit, super capacitor power supply/braking circuit, energy consumption resistance braking circuit and motor drive axle S_moSaid motor drive bridge S_moThe alternating current side is connected with the motor, the direct current side is connected with the positive and negative buses, the lithium battery power supply circuit is connected with the positive and negative buses, and the super capacitor power supply/braking circuit comprises a capacitor voltage reduction bridge S_ecAnd a capacitor boost bridge S_cThe super capacitor sequentially passes through the capacitor voltage reduction bridge S_ecCapacitor boost bridge S_cConnected to the positive and negative busbars, the energy consumption resistance braking circuit comprises an energy consumption voltage reduction bridge S_erSaid energy consumption resistor R_erBy energy consumption step-down bridge S_erConnected to the positive and negative buses, and the control output end of the composite control unit is connected with the motor drive axle S through the PWM generator and the motor drive axle S respectively_moCapacitor voltage reducing bridge S_ecCapacitor boost bridge S_cEnergy consumption voltage reduction bridge S_erAre connected with each other.

Optionally, the lithium battery power supply circuit includes a lithium battery and an inductor L_bThe lithium battery passes through inductor L_bConnected to positive and negative bus bars.

Optionally, the capacitive buck bridge S_ecCapacitor boost bridge S_cWith a capacitor arranged in parallel therebetween.

Optionally, a capacitor C is arranged in parallel between the positive and negative busbars_L。

Optionally, the super capacitor and the capacitive voltage reduction bridge S_ecAn inductor L is connected in series between_ecSaid capacitor step-up bridge S_cAn inductor L is connected in series between the positive bus bar and the negative bus bar_c。

In addition, the invention also provides a control method of the controllable regenerative braking system based on the super capacitor-energy consumption resistor, when the motor system needs to be started or accelerated, the composite control unit closes the energy consumption voltage reduction bridge S_erAnd is openedCapacitor voltage reduction bridge S_ecCapacitor boost bridge S_cThe output voltage of the super capacitor firstly passes through the capacitor voltage reduction bridge S_ecCapacitor boost bridge S_cStep-up to the lithium battery voltage V_highThen together with the lithium battery power supply circuit through a motor drive bridge S_moA drive motor; when the motor system brakes, the motor system is in a super capacitor braking mode by default and is switched to an energy consumption resistance braking mode when a specified trigger condition is met; wherein, the combined control unit closes the energy consumption voltage reduction bridge S in the super capacitor braking mode_erAnd energy consumption voltage reduction bridge S_erAnd turn on the capacitor boost bridge S_cThe kinetic energy of the motor passes through a capacitive step-up bridge S_cAfter boosting, charging the super capacitor to control the speed of the motor; the composite control unit closes the capacitor voltage reduction bridge S in the energy consumption resistance braking mode_ecAnd a capacitor boost bridge S_cAnd starting the energy consumption voltage reduction bridge S_erThe kinetic energy of the motor passes through a power consumption resistor R_erDissipated to control motor speed.

Optionally, the meeting of the specified trigger condition specifically means meeting any one of the following two conditions:

in the above formula, the condition V_busIs the bus voltage of the positive and negative buses, V_thIs a capacitive boost bridge S_cThreshold voltage of V_capIs the voltage of a super capacitor, V_highIs the lithium battery voltage.

Optionally, the hybrid control unit includes a mode switching controller OMSC, a first active disturbance rejection controller ADRC1, a second active disturbance rejection controller ADRC2 and a mode switching controller OMSC, which are implemented in software or hardware, the mode switching controller OMSC is configured to switch to the dynamic resistance braking mode when a specified trigger condition is met during braking of the motor system, the first active disturbance rejection controller ADRC1 is configured to control the motor speed based on the super capacitor braking mode, and the second active disturbance rejection controller ADRC2 is configured to control the motor speed based on the dynamic resistance braking mode.

Optionally, the input of the first active disturbance rejection controller ADRC1 is a motor speed v_bAnd a specified reference velocity v_gThe output is used for controlling a capacitor voltage reduction bridge S through a PWM generator_ec。

Optionally, the input of the second active disturbance rejection controller ADRC2 is a motor speed v_bAnd a specified reference velocity v_gThe output is used for controlling the energy consumption voltage reduction bridge S through the PWM generator_er。

Compared with the prior art, the invention has the following advantages: the invention can control the motor speed and keep the braking torque constant in the regenerative braking process based on the super capacitor, so that the super capacitor can be better applied to a motor transmission system, the kinetic energy of the motor during braking can be stored in the super capacitor as much as possible, and undisturbed switching is realized when the motor braking mode is switched.

Drawings

FIG. 1 is a schematic circuit diagram of a method according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a control principle in the embodiment of the present invention.

FIG. 3 is a schematic diagram of experimental comparison curves in the examples of the present invention.

Detailed Description

As shown in FIG. 1, the controllable regenerative braking system based on the super capacitor-energy consumption resistor of the embodiment comprises a composite control unit, a super capacitor and an energy consumption resistor R_erLithium battery power supply circuit, super capacitor power supply/braking circuit, energy consumption resistance braking circuit and motor drive axle S_moMotor drive axle S_moThe AC side is connected with the motor, the DC side is connected with the positive and negative buses, the lithium battery power supply circuit is connected with the positive and negative buses, the super capacitor power supply/brake circuit comprises a capacitor voltage reduction bridge S_ecAnd a capacitor boost bridge S_cThe super capacitor sequentially passes through the capacitor voltage reduction bridge S_ecCapacitor boost bridge S_cConnected to the positive and negative buses, and the energy consumption resistance braking circuit comprises an energy consumption voltage reduction bridge S_erResistance R of energy consumption_erBy energy consumption step-down bridge S_erConnected to the positive and negative buses, the control output ends of the composite control unit respectively pass throughPWM generator and motor drive axle S_moCapacitor voltage reducing bridge S_ecCapacitor boost bridge S_cEnergy consumption voltage reduction bridge S_erAre connected with each other. In FIG. 1, m_mo、m_ec、m_c、m_erFor modulating the signals, respectively controlling corresponding PWM generators to generate PWM waves to control a motor drive bridge S_moCapacitor voltage reducing bridge S_ecCapacitor boost bridge S_cEnergy consumption voltage reduction bridge S_er。v_bThe motor speed value obtained by measurement is used for motor control.

As shown in FIG. 1, the lithium battery power supply circuit includes a lithium battery and an inductor L_b(labeled L in FIG. 1)_b，R_b) Lithium battery passing inductor L_bAnd the energy storage device is connected to the positive and negative buses and used for storing energy.

As shown in FIG. 1, a super capacitor and a capacitive voltage reduction bridge S_ecAn inductor L is connected in series between_ecCapacitor boost bridge S_cAn inductor L is connected in series between the positive bus bar and the negative bus bar_cIn addition, inductor L_c(labeled L in FIG. 1)_c，R_c) And inductor L_ec(labeled L in FIG. 1)_ec，R_ec) The function is to store energy.

As shown in fig. 1, a capacitive step-down bridge S_ecCapacitor boost bridge S_cThe capacitors are arranged in parallel between the two electrodes, and the effect of stabilizing voltage is achieved. As shown in FIG. 1, a capacitor C is arranged in parallel between the positive and negative electrode bus bars_LCapacitor C_LThe voltage stabilizing capacitors at two ends of the bus play a role in stabilizing the bus voltage.

In addition, the embodiment also provides a control method of the controllable regenerative braking system based on the super capacitor-energy consumption resistor, when the motor system needs to be started or accelerated, the composite control unit closes the energy consumption voltage reduction bridge S_erAnd turn on the capacitor step-down bridge S_ecCapacitor boost bridge S_cThe output voltage of the super capacitor firstly passes through the capacitor voltage reduction bridge S_ecCapacitor boost bridge S_cStep-up to the lithium battery voltage V_highThen together with the lithium battery power supply circuit through a motor drive bridge S_moA drive motor;when the motor system brakes, the motor system is in a super capacitor braking mode by default and is switched to an energy consumption resistance braking mode when a specified trigger condition is met; wherein, the combined control unit closes the energy consumption voltage reduction bridge S in the super capacitor braking mode_erAnd energy consumption voltage reduction bridge S_erAnd turn on the capacitor boost bridge S_cThe kinetic energy of the motor passes through a capacitive step-up bridge S_cAfter boosting, charging the super capacitor to control the speed of the motor; closing of capacitor voltage reduction bridge S by composite control unit in energy consumption resistance braking mode_ecAnd a capacitor boost bridge S_cAnd starting the energy consumption voltage reduction bridge S_erThe kinetic energy of the motor passes through a power consumption resistor R_erDissipated to control motor speed.

In this embodiment, meeting the specified trigger condition specifically means meeting any one of the following two conditions:

in the above formula, the condition V_busIs the bus voltage of the positive and negative buses, V_thIs a capacitive boost bridge S_cThreshold voltage of V_capIs the voltage of a super capacitor, V_highIs the lithium battery voltage. V_bus≤V_thRepresenting bus voltage V_busLess than or equal to the threshold voltage V of the booster circuit_thAt the moment, the kinetic energy of the motor system cannot be stored into the super capacitor continuously; v_cap≥V_highVoltage V representing a supercapacitor_capGreater than or equal to the voltage V of the lithium battery_highAt the moment, the capacity of the super capacitor is full, and the kinetic energy of the motor system cannot be stored into the super capacitor continuously; the two conditions are in the relation of OR, namely, if any one condition is met, the specified trigger condition is met.

As shown in fig. 2, the composite control unit in this embodiment includes a mode switching controller OMSC, a first active disturbance rejection controller ADRC1, a second active disturbance rejection controller ADRC2, and a mode switching controller OMSC implemented by software or hardware, where the mode switching controller OMSC is configured to switch to the dynamic resistor braking mode when a specified trigger condition is met during braking of the motor system, the first active disturbance rejection controller ADRC1 is configured to control the motor speed based on the super capacitor braking mode, and the second active disturbance rejection controller ADRC2 is configured to control the motor speed based on the dynamic resistor braking mode.

The first active disturbance rejection controller ADRC1 is used to control the motor speed based on the super capacitor braking mode. As shown in fig. 2, the input of the first active disturbance rejection controller ADRC1 is the motor speed v_bAnd a specified reference velocity v_gThe output is used for controlling a capacitor voltage reduction bridge S through a PWM generator_ec. Second active disturbance rejection controller ADRC2 is used to control motor speed based on the dynamic resistive braking mode. As shown in fig. 2, the input of the second active disturbance rejection controller ADRC2 is the motor speed v_bAnd a specified reference velocity v_gThe output is used for controlling the energy consumption voltage reduction bridge S through the PWM generator_er. It should be noted that the first active-disturbance-rejection controller ADRC1 and the second active-disturbance-rejection controller ADRC2 are both active-disturbance-rejection controllers, and the active-disturbance-rejection controllers are conventional controller technologies, so detailed descriptions thereof are omitted here.

Mode switching controller principle: the mode switching controller based on event trigger is used for managing controllers connected with the mode switching controller, and the controllers are activated when a trigger condition is met, and the core problem is how to design the trigger condition. In this embodiment, the mode switching controller OMSC operates on the principle that when the trigger condition is satisfied, the second active disturbance rejection controller ADRC2 is activated, and the braking mode of the motor system is switched from the super capacitor braking mode to the dynamic resistor braking mode. When V is_bus≤V_thWhen the braking energy can not be stored in the super capacitor, the motor system can not continue to brake, or when V is_cap≥V_highThe motor system is also unable to continue braking. Energy consumption resistor R_erAlthough energy can be dissipated all the time for braking, the energy cannot be stored, and the kinetic energy of the motor system is converted into the energy consumption resistor R_erThe heat energy of the heat is dissipated. Therefore, the super capacitor should absorb the braking energy as much as possible until the super capacitor cannot store the energy, and then the braking mode is switched from the super capacitor braking mode to the dynamic resistor braking mode. If the trigger condition of the mode switch controller OMSC is fulfilled, the second ADRC2 will be activatedActive, the first active disturbance rejection controller ADRC1 will be turned off and the motor system braking mode is switched from the super capacitor braking mode to the dynamic resistor braking mode. The higher the charging voltage, the faster the super capacitor absorbs energy, and the motor stores the bus voltage V before storing the energy generated during braking into the super capacitor voltage_busBy means of a capacitive step-up bridge S_cIs boosted to a high voltage V_hightHowever, the boost module has a threshold voltage V_thIf V is_bus≤V_thThe boosting module loses the function, the braking energy cannot be stored in the super capacitor, and the bus voltage V is generated when the motor brakes_busThe braking mode is directly proportional to the motor speed, namely the bus voltage is higher as the motor speed is higher, the boosting module loses the effect when the motor speed is lower than a certain value, and at the moment, the mode switching controller needs to switch the braking mode from the super capacitor mode to the energy consumption resistor mode.

In order to prove the performance of the controllable regenerative braking system based on the super capacitor-energy consumption resistor and the application method thereof, a series of experiments are performed in the motor transmission system in the embodiment, and the experimental results are shown in fig. 3. Fig. 3(a) shows the braking effect in the case of braking by the super capacitor, fig. 3(b) shows the braking effect in the case of braking by the dynamic resistor, and fig. 3(c) shows the desired braking effect. It can be seen from the figure that when the motor is braked based on the super capacitor, the motor speed is greater than 3r/s, the braking effect is obvious, the motor speed is lower than 3r/s, almost no braking effect exists, the motor only needs 0.2s to decelerate from the maximum speed to 3r/s, when the motor speed is lower than 3r/s, the motor only can decelerate by means of friction force, and the time consumed for decelerating from 3r/s to 0r/s exceeds 6 s. However, the motor speed can be braked by means of dynamic resistance at any value. Therefore, in order to control the speed of the motor in the whole braking process, the super capacitor and the energy consumption resistor R are required to be used_erIn combination with when V_bus>V_thWhile braking by super capacitor, when V_bus<V_thTime-dependent power consumption resistor R_erAnd (5) braking.

In summary, in order to solve the problem of speed controllability of the motor driving system based on the super capacitor during regenerative braking, the prior art only considers the utilization of the super capacitorThe capacitor and the lithium battery form a hybrid power supply to drive the motor system, and the speed control problem of the motor during regenerative braking is not considered. Therefore, the embodiment provides a hybrid controllable regenerative braking scheme based on a super capacitor and an energy consumption resistor, and the hybrid controllable regenerative braking scheme comprises a circuit topology structure and an undisturbed switching composite control method. The whole speed of the motor can be controlled during regenerative braking, and the two braking modes are switched without disturbance to the speed. When a circuit topological structure is designed, an independent energy recovery circuit is designed for a super capacitor, meanwhile, an independent energy dissipation circuit is also designed for an energy consumption resistor, when a motor starts to brake, kinetic energy of a motor driving system is firstly stored in the super capacitor, and meanwhile, current flowing to the super capacitor is controlled to control the speed of the motor, when the speed of the motor reaches a certain value, a braking mode is switched from a regenerative braking mode based on the super capacitor to an energy consumption resistor dissipation braking mode, and at the moment, the current flowing through the dissipation resistor is also controlled to control the speed of the motor. The switching of the two braking modes will inevitably disturb the speed control of the motor, and in severe cases, the system may be out of control, for this embodiment, a second active disturbance rejection controller ADRC2 is designed, which has the same input parameters and control principle as the first active disturbance rejection controller ADRC1, and is also based on the motor speed v after the second active disturbance rejection controller ADRC2 is activated_bAnd a specified reference velocity v_gOutput is used for control signal and controls energy consumption step-down bridge S through PWM generator_erTherefore, the purposes of no jitter of the control quantity and undisturbed switching during switching are achieved.

The foregoing is merely a system framework for the present invention and is not intended to limit the invention in any manner. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or modify equivalent embodiments, without departing from the scope of the disclosed embodiments. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.