阅读说明：本技术 一种电子换相恒励磁方向制动控制系统 (Electronic phase-changing constant excitation direction brake control system ) 是由 曾庆臣 李岩 于 2019-02-15 设计创作，主要内容包括：本发明专利提供一种电子换相恒励磁方向制动控制系统,包括功率开关管、二极管、电容、电阻、电流传感器、励磁绕组、电枢绕组；本发明专利通过不带触点换相、电机制动能够自由调节、彻底杜绝机械触点换相和制动导致放炮或者爆炸的现象。本发明有益效果为：取消了机械的换相接触器,使用半导体功率管,致使机械结构更简单,对用户使用更方便；由于不存在机械换相接触器,也不存在换相和制动打火的问题,所以就不存在放炮和爆炸的风险；由于不存在机械换相接触器,那就不存在机械触点损坏的问题,大大降低了定期检修的成本；由于实现方式的改进,产品原材料成本,批量化生产的成本都有所下降,总成本会大幅下降。(The invention provides an electronic commutation constant excitation direction brake control system, which comprises a power switch tube, a diode, a capacitor, a resistor, a current sensor, an excitation winding and an armature winding, wherein the power switch tube is connected with the diode; the invention can freely adjust the motor brake by the phase change without a contact, and thoroughly avoid the phenomenon of blasting or explosion caused by the phase change of the mechanical contact and the brake. The invention has the beneficial effects that: a mechanical phase-change contactor is cancelled, and a semiconductor power tube is used, so that the mechanical structure is simpler, and the use is more convenient for users; because there is no mechanical commutation contactor, there is no commutation and braking to strike sparks either, so there is no risk of blasting and explosion; because the mechanical commutation contactor does not exist, the problem of damage of a mechanical contact does not exist, and the cost of regular maintenance is greatly reduced; due to the improvement of the implementation mode, the cost of raw materials of products and the cost of mass production are reduced, and the total cost is greatly reduced.)

1. The electronic commutation constant excitation direction brake control system comprises a power switch tube, a diode, a capacitor, a resistor, a current sensor, an excitation winding and an armature winding, and realizes that the acceleration, the deceleration and the direction of two motors are controlled by one controller.

2. The electronic commutation brake control system of a dual series motor according to claim 1, wherein: the controller controls the rotation direction of the motor, a phase change contactor is not needed, and the rotation direction is realized by power tubes.

3. The electronic commutation brake control system of a dual series motor according to claim 1, wherein: the controller controls the motor to brake in two modes, and energy consumption braking and feedback braking can be realized.

Technical Field

The invention belongs to the field of motor control, and particularly relates to a series excitation direct current double-motor cross connection system with energy consumption and regenerative braking functions and capability of contactless phase change and a controller thereof.

Background

Industrial and mining enterprises, particularly mines, are in harsh environments and relatively closed operating spaces, so that mining locomotives are basically driven by electric power. The current mining driving system comprises a direct current series excitation system and a frequency conversion system: to the frequency conversion system, the problem that exists mainly has: 1. the frequency conversion system has high failure rate in the severe environment of the mining locomotive; 2. the principle of the frequency conversion system is relatively complex, the maintenance is difficult, and the influence on the production is large; 3. the cost of the frequency conversion system is higher with the same power and requirement. For the reasons, the use amount of the frequency conversion system is small; for a direct current series excitation system, the main problems exist: 1. the system principle and the implementation are simple and easy to understand and easy to accept; 2. the system has low failure rate in the severe environment of the mining locomotive; 3. the system is convenient to check and maintain even if the fault problem occurs, and has small influence on production; based on the reasons, the direct current series excitation system has higher convenient and higher market share;

because the locomotive is provided with four wheel hubs, two wheel axles and one motor for each wheel axle, one controller is required to control the acceleration, the deceleration and the direction of the two motors;

the current method is to use a single-switch chopper, then to be equipped with a phase-change switch and a brake resistor, the phase-change switch is used to switch the running direction of the locomotive; the brake resistor is used for carrying out energy consumption braking by connecting the brake resistor after the locomotive brakes; and a single switch chopper is used to regulate locomotive operating speed.

The above working principle causes two outstanding problems:

1. the phase change contactor is used for switching the driving direction, and under the condition of load operation, the contact of the phase change contactor is easy to damage due to frequent sparks, and needs to be checked and replaced regularly;

2. because the brake uses the energy consumption brake of the brake resistor, the resistance value of the resistor is relatively fixed, so the brake force can not be adjusted according to the requirement;

3. because the phase change and the braking are realized by the mechanical contact, if combustible gas exists in the action process, blasting or explosion is inevitably caused;

patent No. CN101552584A discloses a method that enables free switching between dynamic braking and regenerative braking; but two other problems remain.

SUMMARY OF THE PATENT FOR INVENTION

The invention aims to solve the technical problems, and the invention aims to solve three problems: 1. phase change without contact; 2. the motor brake can be freely adjusted; 3. the phenomenon of blasting or explosion caused by phase change and braking is completely avoided.

Compared with the background technology, the invention has the following advantages:

(1) because a mechanical phase-changing contactor is cancelled and a semiconductor power tube is used, the mechanical structure is simpler and the use is more convenient for users;

(2) because there is no mechanical commutation contactor, there is no commutation and braking to strike sparks either, so there is no risk of blasting and explosion;

(3) because the mechanical commutation contactor does not exist, the problem of damage of a mechanical contact does not exist, and the cost of regular maintenance is greatly reduced;

(4) the direction switching and the braking are realized by the semiconductor power tube, so that the action speed is changed, the use is more flexible, and the effect on the performance requirement of a user is better;

(5) due to the improvement of the implementation mode, the cost of raw materials of products and the cost of mass production are reduced, and the total cost is greatly reduced.

Drawings

FIG. 1 is a diagram of the overall topology structure of the dual-motor controller of the invention.

FIG. 2 is a schematic diagram of the equivalent connection of the forward driving of the present invention.

FIG. 3 is an equivalent connection diagram of the inversion driving of the present invention.

FIG. 4 is a normal rotation braking equivalent connection diagram of the invention.

FIG. 5 is a reverse braking equivalent connection diagram of the invention.

FIG. 6 is a diagram of the equivalent connection of the brake resistor of the present invention.

Fig. 7 is an overall system diagram of the present invention patent.

Fig. 8 is a modified topology structure diagram of the patent dual-motor controller of the invention.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Referring to fig. 1, the overall topology structure diagram of the dual-motor controller of the invention is:

1. wherein T1-T7 are power switch tubes, and an equivalent switch and a diode are connected in parallel inside the switch tubes;

2. wherein D is an independent diode;

3. c is a bus cross-over capacitor;

4. r is a discharge resistor;

5. i1, I2 and I3 are current sensors;

6. w1 and M1 are the field winding and armature winding, respectively, of the motor 1;

7. w2 and M2 are the field winding and armature winding, respectively, of the motor 2;

wherein: r, T7, D, I3 constitute a bus overvoltage discharge circuit, which is used for releasing energy through the circuit if the power supply can not absorb feedback energy under the condition of feedback braking; this function may not be needed if the power supply is able to absorb the feedback energy; if the function is in work, the magnitude of the discharge current needs to be detected through I3, and the discharge speed is actively adjusted;

referring to fig. 2, the present invention relates to a positive rotation driving equivalent connection diagram,

1. when the switch is positively rotated, only the T2 is conducted, the T3 is used for PWM chopping to adjust the duty ratio, and the other switch tubes are completely closed;

2. at the moment, the excitation winding and the armature winding of the motor 1 are connected in series, and the armature winding and the excitation winding of the motor 2 are connected in series; then the two are connected in parallel;

3. one end common end of the two parallel motors is connected to a switching tube T2;

4. the common end of the other ends of the two parallel motors is connected to a switching tube T3;

5. the switch tube T6 connects the terminals of the T2 and the T3 which are connected in parallel to form a follow current loop;

6. when the switching tube T3 is turned on, the currents i1 and i2 of the two motors flow together through T3, where it3 is i1+ i2, and it6 is 0;

7. when the switching tube T3 is turned off, the currents i1 and i2 of the two motors freewheel through the body diode of T6, and it3 is 0; it6 ═ i1+ i 2;

referring to fig. 3, the inversion driving equivalent connection diagram of the present invention is shown, in this way,

1. when the reverse rotation is carried out, only the T1 is conducted, the T4 is used for PWM chopping to adjust the duty ratio, and the rest switching tubes are completely closed;

2. at the moment, an armature winding of the motor 1 is connected with a field winding of the motor 2 in series, and the field winding of the motor 1 is connected with the armature winding of the motor 2 in series; then the two are connected in parallel;

3. one end common end of the two parallel motors is connected to a switching tube T1;

4. the common end of the other ends of the two parallel motors is connected to a switching tube T4;

5. the switch tube T5 connects the terminals of the T1 and the T4 which are connected in parallel to form a follow current loop;

6. when the switching tube T4 is turned on, the currents i3 and i4 of the two motors flow together through T4, where it4 is i3+ i4, and it5 is 0;

7. when the switching tube T4 is turned off, the currents i3 and i4 of the two motors freewheel through the body diode of T5, and it4 is 0; it5 ═ i3+ i 4;

8. compared with the forward rotation, the armature winding current direction of the motor 1 is unchanged, and the excitation winding current direction is opposite; the armature winding current direction of the motor 2 is unchanged, and the excitation winding current direction is opposite, so that the phase change requirement is just met;

referring to fig. 4, the patent of the invention discloses an equivalent connection diagram for forward rotation and braking, and the working modes of the method are as follows:

1. under the condition of forward rotation braking, all the switch tubes are closed;

2. under the condition of forward rotation braking, the power switch T5 performs PWM modulation to adjust the magnitude of feedback current;

3. compared with the forward driving, the armature winding of the motor 1 has the opposite current direction, but the field winding has the same current direction, so that resistance is provided; the armature winding current direction of the motor 2 is opposite, but the field winding current direction is unchanged, so the motor 2 also provides resistance;

4. when the switching tube T5 is turned on, the currents i5 and i6 both flow through T5, where it5 is i5+ i 6; it1 is 0; it4 is 0; at the moment, the motor is in a dynamic braking state, and the currents i5 and i6 are gradually increased to store energy for a motor coil;

5. when the switching tube T5 is turned off, currents i5 and i6 pass through body diodes of T1 and T4 to charge the bus, and at this time it 1-it 4-i 5+ i 6; it5 is 0; at the moment, the motor is in a feedback braking state;

referring to fig. 5, the reverse braking equivalent connection diagram of the present invention is shown, in this way,

1. under the condition of reverse braking, all the switch tubes are closed;

2. under the condition of reverse braking, the power switch T6 performs PWM modulation to adjust the magnitude of the feedback current;

3. compared with the reverse drive, the armature winding of the motor 1 has the opposite current direction, but the field winding has the same current direction, so that resistance is provided; the armature winding current direction of the motor 2 is opposite, but the field winding current direction is unchanged, so the motor 2 also provides resistance;

4. when the switching tube T6 is turned on, the currents i7 and i8 both flow through T6, where it6 is i7+ i 8; it2 is it3 is 0; at the moment, the motor is in a dynamic braking state, and the currents i7 and i8 are gradually increased to store energy for a motor coil;

5. when the switching tube T6 is turned off, currents i7 and i8 pass through body diodes of T2 and T3 to charge the bus, and at this time it 2-it 3-i 7+ i 8; it6 is 0; at the moment, the motor is in a feedback braking state;

as shown in fig. 6, the brake resistor of the invention works equivalently,

1. when the control logic finds that the bus voltage V is too high, the power switch tube T7 is opened;

2. the higher V, the higher the duty cycle of T7; otherwise, the lower the duty ratio;

3. where i3 is used to detect the current not to be overcurrent.

As shown in fig. 7, the overall system diagram of the present invention patent includes the following specific working flows:

1. the main loop structure is the topology structure diagram of fig. 1;

2. all control logics are sent out by a control unit;

3. all feedback signals are fed back to the control unit;

4. bus power supplies V + and V-and thus generate various power supplies.

The power switch tube mentioned above includes MOS, IGBT, thyristor, and any power tube capable of starting switching action.

Referring to fig. 8, the invention discloses a modified topology structure diagram of a dual-motor controller, and the key point of the topology is that a switching tube connected with a motor cannot contain a body diode. The diagram is a modification diagram of fig. 1, in which T2 is on, and T3 performs PWM duty ratio adjustment, in which the armature of motor 1 is connected in series with the excitation of motor 1, and the excitation of motor 2 is connected in series with the armature of motor 2; then the terminals of the two serial branches are connected in parallel, one end of the two serial branches is connected to T2, and the other end of the two serial branches is connected to T3; t3 chopping is started, the duty ratio is increased step by step, and the input command value is approached; when the T3 is conducted, the current flows through the T2 from the positive pole of the power supply, is divided into two paths at the T2 and flows into the motor 1 and the motor 2 respectively; after the other common end of the two motors is converged, the current passes through T3 and finally reaches the negative pole of the power supply; when the control unit receives a braking instruction, the T2 and the T3 are turned off at the same time, when the duty ratio of the T4 is gradually increased, the armature current of the motor 1 is reversed, the direction of the exciting current is unchanged, the motor 2 is also the same, the braking current is measured through the current sensor I2, and the duty ratio of the T4 is adjusted according to the requirement of the braking current, so that the braking torque is flexibly controllable.

The working principle of the invention patent is as follows:

an electronic commutation constant excitation direction brake control system comprises a power switch tube, a diode, a capacitor, a resistor, a current sensor, an excitation winding and an armature winding; the mode of operation of this mode is that R, T7, D, I3 constitute a bus overvoltage discharge circuit, which is used for releasing energy through the circuit if the power supply can not absorb feedback energy under the condition of feedback braking; this function may not be needed if the power supply is able to absorb the feedback energy; if this function is in effect, it is necessary to detect the magnitude of the discharge current through I3 and actively adjust the speed of discharge. Firstly, power-on initialization, the control unit at this step makes all preparation work before running (as shown in fig. 7); secondly, power-on diagnosis, wherein a control unit diagnoses voltage (overvoltage and undervoltage faults), motor temperature faults, controller temperature faults, main loop faults and the like; if all is normal, the next step is carried out, otherwise, the alarming step is carried out; thirdly, according to the operation instruction of the user, if the user is moving forward, selecting T2 to be conducted according to the graph of fig. 2, and gradually adjusting the duty ratio of T3 according to the input speed requirement instruction so as to meet the requirement of an output command; at the moment, an excitation winding and an armature winding of the motor 1 are connected in series; the armature winding and the excitation winding of the motor 2 are connected in series, then the two tail ends of the two motors are connected in parallel, one end of the parallel connection is connected to a power switch tube T2, and the other end of the parallel connection is connected to a power switch tube T3; t3 chopping is started, the duty ratio is increased step by step, and the input command value is approached; when the T3 is conducted, the current flows through the T2 from the positive pole of the power supply, is divided into two paths at the T2 and flows into the motor 1 and the motor 2 respectively; after the other common end of the two motors is converged, the current flows through T3 and finally reaches the negative pole of the power supply; fourthly, when the control unit receives a braking instruction, the T2 and the T3 are turned off simultaneously; and fifthly, the duty ratio of the T5 is gradually increased, the magnitude of the brake current is measured through the current sensor I2, and the duty ratio of the T5 is adjusted according to the requirement of the brake current, so that the braking torque is flexible and controllable. At the moment, the armature winding of the motor 1 has induced electromotive force under the condition of rotation, and when the T5 is conducted, the armature of the motor 1 serves as an induction power supply to store energy for the magnet exciting coil and the self coil of the motor 2; meanwhile, an armature winding of the motor 2 is also used as an induction power supply to store energy for an excitation coil and a self coil of the motor 1; when T5 is turned off, the energy stored in the coil freewheels through the body diodes of switching transistors T1 and T4, thereby charging the power supply. When the T5 is conducted, the armature of the motor 1 and the excitation coil of the motor 2 form a loop of the self through the T5, the armature of the motor 2 and the excitation coil of the motor 1 form a loop of the self through the T5, and at the moment, the two motors are in a dynamic braking state; when T5 is turned off, the two independent loops combine the current and then flow through the body diode of T1 to the positive of the power supply, then flow out to the negative of the power supply by charging the power supply reversely, and then flow back to the two branches through the body diode of T4, and at the moment, the two motors are in an energy feedback braking state. The driving and braking in the other direction are the same as above (refer to fig. 3 and 5), and are not described in detail. So far, the electronic commutation and braking functions of the double series excited motor are completed.

In addition, referring to fig. 6, when the control unit in fig. 7 finds that the bus voltage V is too high, the switching tube T7 is turned on according to a predetermined duty ratio, and as V increases, the duty ratio of T7 increases, and conversely decreases, so as to dynamically adjust the bus voltage, and therefore, the purpose that the bus voltage is too high and the device is finally burned due to too high energy of regenerative braking is avoided.

The present invention is not limited to the above-mentioned preferred embodiments, and any other products in various forms can be obtained by anyone in the light of the present invention, but any changes in the method thereof, which have the same or similar technical solutions as the present application, fall within the protection scope of the present invention.