Steel rail grinding motor system

Abstract

A steel rail grinding motor system adopts a switched reluctance motor as a main motor and can be operated and controlled under electric and power generation dual working conditions, a grinding wagon does not need cable connection and external charging, the motor system is composed of a working circuit and a power supply circuit, the working circuit and the power supply circuit are in common ground and have no isolation link, and a motor winding is arranged in the working circuit. Power conversion and operation of the switched reluctance generator and the switched reluctance motor under different working conditions can be completed, direct voltage boosting output can be achieved, a power circuit serves as a power source to supply power to a working circuit, namely, each phase winding of the switched reluctance motor, initial electric energy comes from electric energy output by an internal storage battery or an external working circuit, and the storage battery can be self-charged. The output voltage of the power supply circuit is adjustable, so that the operation performance of the switched reluctance motor can be controlled through the power supply circuit, the whole system is small in number of switching tubes, low in loss and high in repeated utilization rate, the efficiency benefit is further improved, the cost is reduced, the application flexibility is also improved, and the system is suitable for being applied to various rail grinding wagon motor systems in the field of rail transit.

Description

Technical Field

[0001] The present invention relates to the field of rail grinding in the rail transportation industry, and in particular to a high-efficiency grinding motor power conversion system and a control method thereof, which adopts a switched reluctance motor as a rail grinding vehicle motor. Background Art

[0002] In the rail transit industry, including general railways, high-speed railways, urban subways and light rails, especially for passenger trains, the noise level has always been one of the indicators of the quality of the rail transit system, especially when vibration is caused by the quality of the rails, which can seriously affect the speed of the train and even have the risk of derailment.

[0003] The industry often uses a device called a rail grinding vehicle, which uses a high-speed motor on the grinding vehicle to drive the grinding device to grind the rails on the track. This can reduce the noise when the train runs along the rails, reduce the vibration level, eliminate the wavy wear of the rails on curves, and improve the train operation efficiency, etc., which is of great significance to the high-quality, high-speed and safe operation of rail transit facilities.

[0004] The most common motor for rail grinding vehicles is a three-phase asynchronous motor. For example, a typical model has a rated power of 1.5KW and a rated speed of 3000r / min. The required power can be supplied by a cable connection. This method limits the distance that the grinding vehicle can grind the rails at one time, and requires manual continuous plugging in and out of the power supply, and interrupts the work from time to time. The second method is to equip a set of gasoline or diesel generator systems, so that there are at least two motors on the grinding vehicle. Because a special generator is added, although there is no continuous plugging in and out of the power supply in the first method, the volume, weight and cost of the grinding vehicle are bound to increase. The third method is to use a battery for power supply. For a three-phase asynchronous motor, the battery output must be connected to an inverter to convert it into AC power before it can be connected to a three-phase asynchronous motor, which is bound to increase the loss and cost. At the same time, when the battery power is exhausted, the grinding vehicle must stop working and return to the charging place to charge the battery. Of course, if a generator system is added to charge the battery as in the second method, although it can continue to work for a long time, the volume, weight and cost will be further increased.

[0005] The switched reluctance motor has a simple and sturdy structure. The rotor has no windings, so it is easy to dissipate heat and is suitable for high-speed operation. It has strong fault tolerance and is more suitable for harsh environments. It can also easily achieve four-quadrant operation of motoring and generating. As an electric motor, it only needs DC power from a battery as a power source. As a generator, it also directly emits DC power. It is very suitable for use in rail grinding motor systems.

[0006] For rail grinding vehicles, when using an offline power supply solution, the efficiency of electric energy utilization must be a major issue of great concern. Low loss means high efficiency, which can extend working hours, increase work efficiency, and reduce damage caused by temperature rise due to high loss in the power system. Therefore, in the electric energy conversion system, such as reducing isolation links, reducing the number of switching tubes and switching losses, reducing control devices to reduce complexity, effectively utilizing excess energy for reuse, etc., are all major issues that need to be paid attention to and improved at all times.

[0007] In addition, for switched reluctance motors, performance improvements can often also bring about improvements in system efficiency and benefits. In the performance improvement, it is now clear that the control variables are no longer limited to the regulation of switching angles and chopping control parameters, but the regulation of voltage can bring about performance improvements, including the adjustability of key port voltages such as the supply voltage and the voltage during power generation output or residual power output.

[0008] Of course, the use of multiple working modes or dual working effects of the same system will inevitably improve the utilization rate of the system, and often make the entire system lighter and less costly. Summary of the invention

[0009] Purpose of the invention: The purpose of the present invention is to provide a rail grinding electric working system and its control method based on a switched reluctance motor for a rail grinding vehicle with low loss, low cost, high efficiency, high utilization rate and high performance.

[0010] Technical solution: A rail grinding motor system, the motor adopts a switched reluctance motor with a four-phase winding structure, equipped with an internal combustion engine and a battery. The switched reluctance motor can be used as an electric motor to connect to a grinding device to grind rails as needed, and can also be operated as a generator, driven by an internal combustion engine to generate electrical energy to store energy in the battery; the rail grinding motor system consists of a working circuit and a power supply circuit, the output ends of the power supply circuit are connected to the input ends of the working circuit, and the output ends of the working circuit are connected to the input ends of the power supply circuit.

[0011] The working circuit is composed of a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a first phase winding, a second phase winding, a third phase winding, a fourth phase winding, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first inductor, a second inductor, and a third inductor. The anode of the first switch tube is connected to the anode of the second switch tube, the anode of the third switch tube, and the anode of the fourth switch tube, and serves as the positive input terminal of the working circuit. The cathode of the first switch tube is connected to one end of the first phase winding, the cathode of the second switch tube is connected to one end of the second phase winding, the cathode of the third switch tube is connected to one end of the third phase winding, the cathode of the fourth switch tube is connected to one end of the fourth phase winding, the other end of the first phase winding is connected to the other end of the second phase winding, the other end of the third phase winding, the other end of the fourth phase winding, the anode of the first diode, the anode of the second diode, and the positive input terminal of the working circuit. and one end of the second capacitor, the cathode of the first diode is connected to one end of the first capacitor and one end of the first inductor, the other end of the first inductor is connected to the cathode of the second diode, the anode of the fifth switch tube, and the anode of the third diode, the cathode of the third diode is connected to one end of the third capacitor, one end of the fourth capacitor, and one end of the second inductor, the other end of the second inductor is connected to the other end of the second capacitor, the anode of the fourth diode, and one end of the fifth capacitor, the cathode of the fourth diode is connected to the other end of the fourth capacitor and one end of the third inductor, the other end of the third inductor is connected to the other end of the fifth capacitor and the anode of the fifth diode, the cathode of the fifth diode is connected to one end of the sixth capacitor, and serves as the positive output terminal of the working circuit, the other end of the sixth capacitor is connected to the cathode of the fifth switch tube, the other end of the first capacitor, and the other end of the third capacitor, and serves as the negative input terminal and the negative output terminal of the working circuit; the first phase winding, the second phase winding, the third phase winding, and the fourth phase winding constitute the four-phase winding of the switched reluctance motor.

[0012] The power supply circuit is composed of a sixth switch tube, a seventh switch tube, an eighth switch tube, a sixth diode, a seventh diode, an eighth diode, a ninth diode, a tenth diode, a seventh capacitor, an eighth capacitor, a fourth inductor, a fifth inductor, and a battery. The anode of the sixth diode is connected to the positive output terminal of the working circuit as the input positive terminal of the power supply circuit, the cathode of the sixth diode is connected to the anode of the sixth switch tube and one end of the seventh capacitor, the cathode of the sixth switch tube is connected to the cathode of the seventh diode and one end of the fourth inductor, the other end of the fourth inductor is connected to the anode of the seventh switch tube and the anode of the ninth diode, the cathode of the seventh switch tube is connected to the anode of the eighth diode, the cathode of the eighth diode is connected to one end of the fifth inductor and the positive electrode of the battery, the other end of the fifth inductor is connected to the anode of the eighth switch tube and the anode of the tenth diode, the cathode of the tenth diode is connected to the cathode of the ninth diode and one end of the eighth capacitor, and is connected to the positive input terminal of the working circuit as the output positive terminal of the power supply circuit, the other end of the eighth capacitor is connected to the cathode of the eighth switch tube, the anode of the seventh diode, the other end of the seventh capacitor, and the negative electrode of the battery, and is connected to the negative input terminal and the negative output terminal of the power supply circuit, and is connected to the negative input terminal and the negative output terminal of the working circuit.

[0013] When the switched reluctance motor of the present invention is operated as an electric working mode to grind rails, the power supply circuit outputs electric energy to supply power to the working circuit. According to the rotor position information of the switched reluctance motor, when the first phase winding needs to be put into operation, the first switch tube and the fifth switch tube are closed and turned on, and the power supply circuit supplies power to the first phase winding through the first switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor is output through the output end of the working circuit when there is energy stored. output; according to the rotor position information, when the first phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the first phase winding drops to zero. It outputs electric energy to the output end of the working circuit through the fifth diode together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor through the first switch tube, the first diode, and the third diode together with the first phase winding and the power circuit; when the phase current of the first phase winding drops to zero, the first switch tube is turned off, and the operation of the first phase winding ends;

[0014] According to the rotor position information of the switched reluctance motor, when the second phase winding needs to be put into operation, the second switch tube and the fifth switch tube are closed and turned on, and the power circuit supplies power to the second phase winding through the second switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor outputs energy through the output end of the working circuit alone when there is energy storage; according to the rotor position information, when the second phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the second phase winding drops to zero. It outputs electric energy to the output end of the working circuit through the fifth diode together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor through the second switch tube, the first diode, and the third diode together with the second phase winding and the power circuit; when the phase current of the second phase winding drops to zero, the second switch tube is turned off, and the operation of the second phase winding ends;

[0015] According to the rotor position information of the switched reluctance motor, when the third phase winding needs to be put into operation, the third switch tube and the fifth switch tube are closed and turned on, and the power circuit supplies power to the third phase winding through the third switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor outputs energy through the output end of the working circuit alone when there is energy storage; according to the rotor position information, when the third phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the third phase winding drops to zero. It outputs electric energy to the output end of the working circuit through the fifth diode together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor through the third switch tube, the first diode, and the third diode together with the third phase winding and the power circuit; when the phase current of the third phase winding drops to zero, the third switch tube is turned off, and the operation of the third phase winding ends;

[0016] According to the rotor position information of the switched reluctance motor, when the fourth phase winding needs to be put into operation, the fourth switch tube and the fifth switch tube are closed and turned on, and the power circuit supplies power to the fourth phase winding through the fourth switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor outputs energy through the output end of the working circuit alone when there is energy storage; according to the rotor position information, when the fourth phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the fourth phase winding drops to zero. It outputs electric energy to the output end of the working circuit together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor together with the fourth phase winding and the power circuit through the fourth switch tube, the first diode, and the third diode; when the phase current of the fourth phase winding drops to zero, the fourth switch tube is turned off, and the operation of the fourth phase winding ends.

[0017] When the internal combustion engine drives the switched reluctance motor to operate as a generator, the power circuit outputs electrical energy to the working circuit as an excitation power supply. According to the rotor position information of the switched reluctance motor, when the first phase winding needs to be put into operation, the first switch tube and the fifth switch tube are closed and turned on to enter the first working stage of the first phase winding, namely the excitation stage. The power circuit supplies power to the first phase winding for excitation through the first switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the output end of the working circuit is maintained by the sixth capacitor. Output; According to the rotor position information, when the excitation stage of the first phase winding needs to end, the fifth switch tube is disconnected, and the second working stage of the first phase winding, i.e., the power generation stage, is entered. The first phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the first phase winding and the power circuit, charges the third capacitor through the first switch tube, the first diode, and the third diode; When the power generation stage needs to end according to the rotor position information, the first switch tube is disconnected, and the first phase winding ends its work;

[0018] According to the rotor position information of the switched reluctance motor, when the second phase winding needs to be put into operation, the second switch tube and the fifth switch tube are closed and turned on, and the first working stage of the second phase winding, i.e., the excitation stage, is entered. The power circuit supplies power to the second phase winding for excitation through the second switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, and the second capacitor, the first inductor, the second inductor, and the third inductor are charged. The output end of the working circuit relies on the sixth capacitor to maintain the output; according to the rotor position information, when the excitation stage of the second phase winding needs to be ended, the fifth switch tube is disconnected, and the second working stage of the second phase winding, i.e., the power generation stage, is entered. The second phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the second phase winding and the power circuit, charges the third capacitor through the second switch tube, the first diode, and the third diode; when the power generation stage needs to be ended according to the rotor position information, the second switch tube is disconnected, and the second phase winding ends its operation;

[0019] According to the rotor position information of the switched reluctance motor, when the third phase winding needs to be put into operation, the third switch tube and the fifth switch tube are closed and turned on, and the first working stage of the third phase winding, i.e., the excitation stage, is entered. The power circuit supplies power to the third phase winding for excitation through the third switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, and the second capacitor, the first inductor, the second inductor, and the third inductor are charged. The output end of the working circuit relies on the sixth capacitor to maintain the output; according to the rotor position information, when the excitation stage of the third phase winding needs to be ended, the fifth switch tube is disconnected, and the second working stage of the third phase winding, i.e., the power generation stage, is entered. The third phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the third phase winding and the power circuit, charges the third capacitor through the third switch tube, the first diode, and the third diode; when the power generation stage needs to be ended according to the rotor position information, the third switch tube is disconnected, and the work of the third phase winding ends;

[0020] According to the rotor position information of the switched reluctance motor, when the fourth phase winding needs to be put into operation, the fourth switch tube and the fifth switch tube are closed and turned on, and the first working stage of the fourth phase winding, i.e., the excitation stage, is entered. The power circuit supplies power to the fourth phase winding for excitation through the fourth switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the output end of the working circuit relies on the sixth capacitor to maintain the output; according to the rotor position information, when the excitation stage of the fourth phase winding needs to be ended, the fifth switch tube is disconnected, and the second working stage of the fourth phase winding, i.e., the power generation stage, is entered. The fourth phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the fourth phase winding and the power circuit, charges the third capacitor through the fourth switch tube, the first diode, and the third diode; when the power generation stage needs to be ended according to the rotor position information, the fourth switch tube is disconnected, and the operation of the fourth phase winding ends.

[0021] The power supply circuit has three control working modes. The first working mode is that when the switched reluctance motor operates as a generator, the input end of the power supply circuit receives electric energy from the output end of the working circuit. In addition to outputting the excitation power supply as the switched reluctance generator, the power supply circuit also charges the battery. In this working mode, the eighth switch tube remains in the off state, and the sixth and seventh switch tubes work in PWM mode switching. The switching frequencies of the two are the same. When the sixth switch tube is turned off, the seventh switch tube is turned on, and the sum of the PWM duty cycles of the two is less than 1.

[0022] The second working mode of the power supply circuit is a mode in which electric energy is input to the input end of the power supply circuit and outputs electric energy to the output end of the power supply circuit together with the battery. In this mode, the switched reluctance motor operates as a motor, and the electric energy output by the working circuit is converted from the residual magnetic energy of each phase winding. The battery is used as the second power supply for power supply. The seventh switch tube maintains the off state, and the sixth and eighth switch tubes switch in PWM mode. The two switch frequencies are the same and are turned on at the same time. The PWM duty cycle of the sixth switch tube is greater than the PWM duty cycle of the eighth switch tube.

[0023] The third working mode of the power supply circuit is a mode in which the battery is used alone as a power source to supply power to the working circuit through the power supply circuit output, the sixth switch tube and the seventh switch tube are both maintained in the off state, and only the eighth switch tube works in PWM mode.

[0024] The beneficial effects of the present invention are:

[0025] 1. In the field of rail grinding, a rail grinding motor system of the present invention does not require external power supply, so that the grinding device can move freely and work over a long distance on the track without dragging cables, and the equipped battery can also convert the switched reluctance motor used into a generator mode for autonomous charging, without the need for a special charging device, thereby greatly enhancing the flexibility of the entire grinding system.

[0026] 2. It can be seen from the working circuit and power circuit structure of the present invention that the two share a common ground and have no isolation link, thereby greatly reducing the increase in loss caused by isolation.

[0027] 3. Although there are five switching tubes in the working circuit, only two switching tubes are performing switching work in real time. Compared with the number of switching tubes with twice the number of phase windings in the traditional switched reluctance motor power conversion system, the number has been significantly reduced, thereby reducing control complexity and losses.

[0028] 4. When the switched reluctance generator is working, it can be seen from the two-stage working process of the working circuit that the voltage at the output end of the working circuit is significantly greater than the voltage at the output end of the power supply circuit (excitation voltage) and the phase winding voltage. In addition, since the output end of the power supply circuit and the corresponding phase winding, the corresponding capacitor and the inductor are connected in series for output, a direct boost output effect can be obtained. If the voltage at the output end of the power supply circuit is adjusted (i.e., variable excitation voltage adjustment), it will affect the change of the voltage value at the output end of the working circuit, thereby indirectly adjusting the generated voltage value.

[0029] 5. The first working mode of the power supply circuit can realize the operation control of the switched reluctance generator with variable excitation voltage, while charging the battery at the same time, killing two birds with one stone and improving work efficiency.

[0030] 6. In the second working mode of the power supply circuit, in addition to the variable voltage output as the power supply of the switched reluctance motor, the input end fully utilizes the residual energy generated by the switched reluctance motor as one of the inputs, which greatly improves the overall power efficiency.

[0031] 7. Regardless of the working mode of the power supply circuit, variable voltage output control can be achieved; and, from the structure of the power supply circuit, it can be seen that although there are a total of three switching tubes, when the three modes are working, at most only two switching tubes are working, and in the third working mode, only one switching tube works in PWM mode, and the overall switching loss is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Shown is a structural diagram of a rail grinding motor system of the present invention.

[0033] Figure 2 The figure shows the phase winding inductance and current analysis of the switched reluctance motor at different stator and rotor angle positions.

[0034] Figure 3 The figure shows the first working stage of the first phase winding of the working circuit of the motor system of the present invention.

[0035] Figure 4 The figure shows the second working stage of the first phase winding of the working circuit of the motor system of the present invention.

[0036] Figure 5 Shown is a switching timing diagram of the first working mode of the motor system power supply circuit of the present invention.

[0037] Figure 6 Shown is a switching timing diagram of the second working mode of the motor system power supply circuit of the present invention.

[0038] Figure 7 Shown is a switching timing diagram of the third working mode of the motor system power supply circuit of the present invention.

[0039] Figure 1 In the figure: 1 is the working circuit; 2 is the power supply circuit. DETAILED DESCRIPTION

[0040] A rail grinding motor system, which in this embodiment refers to a motor system for a grinding vehicle for ground rails in the field of rail transportation. The motor adopts a switched reluctance motor with a four-phase winding, an eight-pole stator and a six-pole rotor structure. The grinding vehicle does not need to be connected to an external power supply. The vehicle is equipped with an internal combustion engine and a battery. The switched reluctance motor can be used as an electric motor to connect a grinding device to grind rails as needed, and can also be used as a generator driven by an internal combustion engine to generate electrical energy for storage in the battery.

[0041] The rail grinding motor system of this embodiment is composed of a working circuit 1 and a power supply circuit 2. Figure 1 As shown, the two output ends of the power supply circuit 2 are connected to the two input ends of the working circuit 1, and the two output ends of the working circuit 1 are connected to the two input ends of the power supply circuit 2.

[0042] The working circuit 1 is composed of a first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a fifth switch tube S5, a first phase winding M, a second phase winding N, a third phase winding P, a fourth phase winding Q, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a first inductor L1, a second inductor L2, and a third inductor L3, as shown in the attached figure. Figure 1As shown, the anode of the first switch tube S1 is connected to the anode of the second switch tube S2, the anode of the third switch tube S3, and the anode of the fourth switch tube S4, and serves as the positive input terminal of the working circuit 1. The cathode of the first switch tube S1 is connected to one end of the first phase winding M, the cathode of the second switch tube S2 is connected to one end of the second phase winding N, the cathode of the third switch tube S3 is connected to one end of the third phase winding P, and the cathode of the fourth switch tube S4 is connected to one end of the fourth phase winding Q. The other end of the first phase winding M is connected to the other end of the second phase winding N, the other end of the third phase winding P, the other end of the fourth phase winding Q, the anode of the first diode D1, the anode of the second diode D2, and one end of the second capacitor C2. The cathode of the first diode D1 is connected to one end of the first capacitor C1 and one end of the first inductor L1. The other end of the first inductor L1 is connected to the cathode of the second diode D2, the anode of the fifth switch tube S5, and the anode of the third diode D3. The cathode of the diode D3 is connected to one end of the third capacitor C3, one end of the fourth capacitor C4, and one end of the second inductor L2. The other end of the second inductor L2 is connected to the other end of the second capacitor C2, the anode of the fourth diode D4, and one end of the fifth capacitor C5. The cathode of the fourth diode D4 is connected to the other end of the fourth capacitor C4 and one end of the third inductor L3. The other end of the third inductor L3 is connected to the other end of the fifth capacitor C5 and the anode of the fifth diode D5. The cathode of the fifth diode D5 is connected to one end of the sixth capacitor C6 and serves as the output positive terminal of the working circuit 1. The other end of the sixth capacitor C6 is connected to the cathode of the fifth switch tube S5, the other end of the first capacitor C1, and the other end of the third capacitor C3, and serves as the input negative terminal and output negative terminal of the working circuit 1. The first phase winding M, the second phase winding N, the third phase winding P, and the fourth phase winding Q constitute the four-phase winding of the switched reluctance motor.

[0043] The power supply circuit 2 is composed of a sixth switch tube S6, a seventh switch tube S7, an eighth switch tube S8, a sixth diode D6, a seventh diode D7, an eighth diode D8, a ninth diode D9, a tenth diode D10, a seventh capacitor C7, an eighth capacitor C8, a fourth inductor L4, a fifth inductor L5, and a battery B, as shown in the attached figure. Figure 1As shown, the anode of the sixth diode D6 is connected to the positive output terminal of the working circuit 1 as the input positive terminal of the power supply circuit 2, the cathode of the sixth diode D6 is connected to the anode of the sixth switch tube S6 and one end of the seventh capacitor C7, the cathode of the sixth switch tube S6 is connected to the cathode of the seventh diode D7 and one end of the fourth inductor L4, the other end of the fourth inductor L4 is connected to the anode of the seventh switch tube S7 and the anode of the ninth diode D9, the cathode of the seventh switch tube S7 is connected to the anode of the eighth diode D8, the cathode of the eighth diode D8 is connected to one end of the fifth inductor L5 and the positive electrode of the battery B, the other end of the fifth inductor L5 is connected to the anode of the eighth switch tube S8 and the anode of the tenth diode D10, the cathode of the tenth diode D10 is connected to the cathode of the ninth diode D9 and one end of the eighth capacitor C8, and is connected to the positive input terminal of the working circuit 1 as the output positive terminal of the power supply circuit 2, the other end of the eighth capacitor C8 is connected to the cathode of the eighth switch tube S8, the anode of the seventh diode D7, the other end of the seventh capacitor C7, and the negative electrode of the battery B, and serves as the negative input terminal and the negative output terminal of the power supply circuit 2, and is connected to the negative input terminal and the negative output terminal of the working circuit 1.

[0044] It can be seen from the above structure that the working circuit 1 and the power circuit 2 share a common ground and have no isolation link.

[0045] Regarding the working mechanism of the switched reluctance motor of this embodiment, the switched reluctance motor selects the phase winding that needs to be energized and put into operation according to the real-time position relationship between the stator and the rotor. The relationship between the inductance of the phase winding of the switched reluctance motor and the position angle between the stator and the rotor is as follows: Figure 2 As shown, the inductance L(θ) of each phase winding wound on the stator salient pole changes regularly and periodically with the position relationship with the rotor. The position where the center line of the stator salient pole and the center line of the rotor groove coincide is set as the angle zero point. The phase inductance is minimum in the interval of θ1 to θ2, and the phase inductance rises from θ2 to θ3. The phase inductance is maximum in the region where the center lines of the stator and rotor salient poles coincide from θ3 to θ4, and is the phase inductance decreases from θ4 to θ5.

[0046] The voltage balance equation of the phase winding of the switched reluctance motor can be written as:

[0047]

[0048] In formula (1), U is the phase winding terminal voltage; R is the phase winding resistance; i is the phase winding current; L is the phase winding inductance; dθ / dt represents the rotor angular velocity of the switched reluctance motor. If the phase winding resistance is ignored, and it is assumed that L is independent of i, and dθ / dt = Ω, the phase winding voltage balance equation can be simplified to:

[0049]

[0050] In formula (2) is the transformer electromotive force, i.e. the electromotive force induced by the change of phase current; It represents that the phase winding is different from simple inductance. It is the electromotive force induced by the phase inductance changing with the rotor position when the motor rotates, which is called motion electromotive force. It can be seen that the greater the phase winding inductance and its rate of change, the greater the phase current and its rate of change, and the higher the speed, the greater the phase winding terminal voltage.

[0051] The electromagnetic torque formula of the switched reluctance motor can be written as:

[0052]

[0053] It can be seen that when the inductance is in a constant region, that is, the θ1~θ2 and θ3~θ4 regions, the electromagnetic torque is zero; the greater the inductance change rate, the greater the torque, and the torque is proportional to the square of the current; the direction of the torque is independent of the current direction, but is related to the direction of change of the winding inductance, so even under unidirectional current, the four-quadrant operation of the switched reluctance motor (forward motoring, forward power generation, reverse motoring, reverse power generation) can be easily realized; when operating as a switched reluctance motor, the absorbed electrical energy is converted into mechanical energy, and the electromagnetic torque should be positive, that is, the inductance rising region (θ2~θ3) is its effective region; when operating as a switched reluctance generator, mechanical energy needs to be stored, and the electromagnetic torque should be negative, that is, the inductance decreasing region (θ4~θ5) is its effective region.

[0054] From the above, we can see the particularity and unique characteristics of the switched reluctance motor compared with other motors. Based on this, the following continues according to the attached Figure 2 The phase winding currents are further analyzed.

[0055] The waveform of the phase current, according to equations (2) and (3), and Figure 2 As shown in the figure, the trend of change is different with different inductance regions. When the switched reluctance motor is operated as a motor, in theory, it is necessary to be in the θ2~θ3 region to energize the corresponding phase winding to establish positive torque for electric operation. In practice, according to formula (2), compared with the θ2~θ3 region, in the θ1~θ2 region, although the torque of the former is zero, the phase current increases faster relatively because the motive electromotive force is also zero after power is turned on. Therefore, in order to establish the phase current faster, the opening angle θ during electric operation is on1 Generally, the power is turned on before θ2, such as Figure 2 As shown in the figure, after the corresponding phase winding of the switched reluctance motor is energized at time t0, the current rises rapidly before the angle θ2, i.e., before t1, and the turn-off angle θ off1 Assume that it is turned off before θ3, such as Figure 2 It is turned off at time t3, so that the phase current drops to zero and the operation of this phase winding ends.

[0056] When the switched reluctance motor operates as a generator, the work of each phase winding is divided into two major stages and is carried out in different time periods. The first is the excitation stage, which is mainly for absorbing and storing energy, followed by the power generation stage. Although θ4~θ5 is its effective area, in order to generate electricity more efficiently, the phase current must be established in advance, that is, the excitation must be energized in advance. Generally, the excitation is started before θ3. Figure 2 It can be seen that the excitation stage can be divided into three sub-stages, and the power generation stage can be divided into two sub-stages:

[0057] (1) t2-t4: This stage is in the rising zone before the phase inductance rises to the maximum value. The phase winding absorbs electrical energy, part of which is converted into mechanical energy output (i.e. the main operating range of the switched reluctance motor), and the other part belongs to the inductance characteristic, that is, as an increment of magnetic field energy storage. Since the inductance is close to the maximum inductance zone at this time, the value is large, and The phase current rises slowly. In theory, for the switched reluctance generator, the opening angle θ on2 Although this area is not a valid area, a non-zero starting value can be obtained in advance for the establishment of the subsequent phase current, which is beneficial for faster establishment of the phase current in the subsequent excitation stage.

[0058] (2) t4~t5: According to formula (2), at this time, due to The phase current will rise rapidly in a linear manner, and the electrical energy absorbed by the phase winding will be completely converted into magnetic field energy storage. At this stage, the phase winding is similar to an inductor element.

[0059] (3) t5~t6: Since this time The phase current rises very quickly, the electromagnetic torque is negative, and the absorbed electrical energy and mechanical energy are converted into magnetic field energy storage. This stage is the last sub-stage of the excitation stage and is also the most effective excitation stage. Extending t6, that is, the excitation cut-off angle θ off2 If t6 is delayed, the final value of the phase current will increase, which will be very beneficial to the storage of magnetic field energy. However, if t6 is extended too much, the effective area of ​​the subsequent power generation stage will be reduced, reducing the system efficiency.

[0060] (4) t6-t7: This stage is the first sub-stage of the power generation stage. The phase winding absorbs mechanical energy and converts it into electrical energy output. It is the most effective power generation output area. The kinetic electromotive force and electromagnetic torque are negative. When the kinetic electromotive force is greater than the phase winding terminal voltage, the phase current will continue to rise. When the speed is low, that is, the kinetic electromotive force is less than the phase winding voltage, the phase current will decrease.

[0061] (5) t7~t8: Since this time And the phase inductance reaches the minimum value and drops rapidly under the action of the phase winding terminal voltage. At the same time, the magnetic energy in the phase winding is converted into electrical energy output, which is also a relatively effective power generation output area.

[0062] From the above process, it can be seen that stages (1)(2)(3) are the excitation stages of the switched reluctance generator phase windings, and (4)(5) are the generation stages of the switched reluctance generator phase windings. The electric energy output in the generation stage minus the electric energy absorbed in the excitation stage is the effective power output of the switched reluctance generator. Therefore, the selection of the turn-on angle and the turn-off angle is very important.

[0063] Based on the above theoretical analysis, the current chopping control (CCC) and switching angle control (APC) methods of the switched reluctance motor are not difficult to understand; in addition, the control of the switched reluctance motor can also be indirectly achieved by changing the power supply voltage supplied to the phase winding. The voltage PWM control method is to achieve control by changing the power supply phase voltage by adjusting the voltage PWM duty cycle. For the switched reluctance generator, the voltage is the excitation voltage.

[0064] From the working mechanism of the switched reluctance motor described above, it can be seen that as long as different opening angles and closing angles are adjusted according to the position relationship between the stator and the rotor, the motoring or generating operation can be realized, which is specifically realized by the working circuit 1 of this embodiment. When the rail grinding operation is performed as a motoring operation, the power supply circuit 2 outputs electric energy to supply power to the working circuit 1. According to the rotor position information of the switched reluctance motor, when the first phase winding M needs to be put into operation, the first switch tube S1 and the fifth switch tube S5 are closed and turned on, as shown in the attached figure. Figure 3 As shown, the power circuit 2 supplies power to the first phase winding M through the first switch tube S1, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the sixth capacitor C6 outputs energy through the output end of the working circuit 1 when energy is stored; according to the rotor position information, when the first phase winding M needs to end its operation, the fifth switch tube S5 is disconnected, as shown in the attached figure. Figure 4 As shown, at this time, there is still residual energy storage before the phase current of the first phase winding M drops to zero, and it outputs electric energy to the output end of the working circuit 1 through the fifth diode D5 together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, and also charges the sixth capacitor C6, the first capacitor C1 is charged, and the first inductor L1 also charges the third capacitor C3 through the first switch tube S1, the first diode D1, and the third diode D3 together with the first phase winding M and the power circuit 2; when the phase current of the first phase winding M drops to zero, the first switch tube S1 is turned off, and the operation of the first phase winding M ends;

[0065] According to the rotor position information of the switched reluctance motor, when the second phase winding N needs to be put into operation, the second switch tube S2 and the fifth switch tube S5 are closed and turned on, and the power supply circuit 2 supplies power to the second phase winding N through the second switch tube S2, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the sixth capacitor C6 outputs energy through the output end of the working circuit 1 when there is energy stored; according to the rotor position information, when the second phase winding N needs to stop working, The fifth switch tube S5 is turned off. At this time, there is still residual energy before the phase current of the second phase winding N drops to zero. It outputs electric energy to the output end of the working circuit 1 through the fifth diode D5 together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, and also charges the sixth capacitor C6. The first capacitor C1 is charged. The first inductor L1 also charges the third capacitor C3 through the second switch tube S2, the first diode D1, and the third diode D3 together with the second phase winding N and the power circuit 2. When the phase current of the second phase winding N drops to zero, the second switch tube S2 is turned off, and the operation of the second phase winding N ends.

[0066] According to the rotor position information of the switched reluctance motor, when the third phase winding P needs to be put into operation, the third switch tube S3 and the fifth switch tube S5 are closed and turned on, and the power supply circuit 2 supplies power to the third phase winding P through the third switch tube S3, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the sixth capacitor C6 outputs energy through the output end of the working circuit 1 when there is energy stored; according to the rotor position information, when the third phase winding P needs to stop working, The fifth switch tube S5 is turned off. At this time, there is still residual energy before the phase current of the third phase winding P drops to zero. It outputs electric energy to the output end of the working circuit 1 through the fifth diode D5 together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, and also charges the sixth capacitor C6. The first capacitor C1 is charged. The first inductor L1 also charges the third capacitor C3 through the third switch tube S3, the first diode D1, and the third diode D3 together with the third phase winding P and the power circuit 2. When the phase current of the third phase winding P drops to zero, the third switch tube S3 is turned off, and the work of the third phase winding P ends;

[0067] According to the rotor position information of the switched reluctance motor, when the fourth phase winding Q needs to be put into operation, the fourth switch tube S4 and the fifth switch tube S5 are closed and turned on, and the power supply circuit 2 supplies power to the fourth phase winding Q through the fourth switch tube S4, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the sixth capacitor C6 outputs energy through the output end of the working circuit 1 when there is energy stored; according to the rotor position information, when the fourth phase winding Q needs to stop working, The fifth switch tube S5 is turned off. At this time, there is still residual energy before the phase current of the fourth phase winding Q drops to zero. It outputs electric energy to the output end of the working circuit 1 through the fifth diode D5 together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, and also charges the sixth capacitor C6. The first capacitor C1 is charged, and the first inductor L1 also charges the third capacitor C3 through the fourth switch tube S4, the first diode D1, and the third diode D3 together with the fourth phase winding Q and the power circuit 2; when the phase current of the fourth phase winding Q drops to zero, the fourth switch tube S4 is turned off, and the operation of the fourth phase winding Q ends.

[0068] When the internal combustion engine drives the switched reluctance motor to operate as a generator, the power supply circuit 2 outputs power to the working circuit 1 as an excitation power supply. According to the rotor position information of the switched reluctance motor, when the first phase winding M needs to be put into operation, the first switch tube S1 and the fifth switch tube S5 are closed and turned on, as shown in the attached figure. Figure 3 As shown, the first working stage of the first phase winding M, i.e., the excitation stage, is entered. The power circuit 2 supplies power to the first phase winding M for excitation via the first switch tube S1, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the output end of the working circuit 1 relies on the sixth capacitor C6 to maintain the output; according to the rotor position information, when the excitation stage of the first phase winding M needs to end, the fifth switch tube S5 is disconnected, as shown in the attached figure. Figure 4 As shown, the first phase winding M enters the second working stage, i.e., the power generation stage. The first phase winding M, together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, outputs electric energy to the output end of the working circuit 1 through the fifth diode D5, and also charges the sixth capacitor C6. The first capacitor C1 is also charged. The first inductor L1, together with the first phase winding M and the power circuit 2, charges the third capacitor C3 through the first switch tube S1, the first diode D1, and the third diode D3. When the power generation stage needs to end according to the rotor position information, the first switch tube S1 is disconnected, and the first phase winding M ends its work.

[0069] According to the rotor position information of the switched reluctance motor, when the second phase winding N needs to be put into operation, the second switch tube S2 and the fifth switch tube S5 are closed and turned on, and the first working stage of the second phase winding N, i.e., the excitation stage, is entered. The power supply circuit 2 supplies power to the second phase winding N for excitation through the second switch tube S2, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the output end of the working circuit 1 relies on the sixth capacitor C6 to maintain the output; according to the rotor position information, when the second phase winding N is excited, When the stage needs to end, the fifth switch tube S5 is turned off, and the second working stage of the second phase winding N, i.e., the power generation stage, is entered. The second phase winding N, together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, outputs electric energy to the output end of the working circuit 1 through the fifth diode D5, and also charges the sixth capacitor C6. The first capacitor C1 is also charged, and the first inductor L1, together with the second phase winding N and the power circuit 2, charges the third capacitor C3 through the second switch tube S2, the first diode D1, and the third diode D3; when the power generation stage needs to end according to the rotor position information, the second switch tube S2 is turned off, and the second phase winding N ends its work;

[0070] According to the rotor position information of the switched reluctance motor, when the third phase winding P needs to be put into operation, the third switch tube S3 and the fifth switch tube S5 are closed and turned on, and the first working stage of the third phase winding P, i.e., the excitation stage, is entered. The power supply circuit 2 supplies power to the third phase winding P for excitation through the third switch tube S3, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the output end of the working circuit 1 relies on the sixth capacitor C6 to maintain the output; according to the rotor position information, when the third phase winding P is excited, When the stage needs to end, the fifth switch tube S5 is turned off, and the second working stage of the third phase winding P, i.e., the power generation stage, is entered. The third phase winding P, together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, outputs electric energy to the output end of the working circuit 1 through the fifth diode D5, and also charges the sixth capacitor C6. The first capacitor C1 is also charged, and the first inductor L1, together with the third phase winding P and the power circuit 2, charges the third capacitor C3 through the third switch tube S3, the first diode D1, and the third diode D3; when the power generation stage needs to end according to the rotor position information, the third switch tube S3 is turned off, and the work of the third phase winding P ends;

[0071] According to the rotor position information of the switched reluctance motor, when the fourth phase winding Q needs to be put into operation, the fourth switch tube S4 and the fifth switch tube S5 are closed and turned on, and the first working stage of the fourth phase winding Q, i.e., the excitation stage, is entered. The power supply circuit 2 supplies power to the fourth phase winding Q for excitation through the fourth switch tube S4, the second diode D2, and the fifth switch tube S5. At the same time, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are discharged, the second capacitor C2, the first inductor L1, the second inductor L2, and the third inductor L3 are charged, and the output end of the working circuit 1 relies on the sixth capacitor C6 to maintain the output; according to the rotor position information, when the fourth phase winding Q is excited, When the stage needs to end, the fifth switch tube S5 is turned off, and the second working stage of the fourth phase winding Q, i.e., the power generation stage, is entered. The fourth phase winding Q, together with the second capacitor C2, the third inductor L3, the fifth capacitor C5, and the power circuit 2, outputs electric energy to the output end of the working circuit 1 through the fifth diode D5, and also charges the sixth capacitor C6. The first capacitor C1 is also charged, and the first inductor L1, together with the fourth phase winding Q and the power circuit 2, charges the third capacitor C3 through the fourth switch tube S4, the first diode D1, and the third diode D3; when the power generation stage needs to end according to the rotor position information, the fourth switch tube S4 is turned off, and the fourth phase winding Q ends its work.

[0072] From the above, it can be seen that the switched reluctance motor operates as a motor and a generator. Although the working circuit 1 has five switching tubes, only two switching tubes are performing switching work in real time, and the five switching tubes are significantly reduced compared with the number of switching tubes in the traditional switched reluctance motor power conversion system with twice the number of phase windings.

[0073] From the above two-stage working process of the switched reluctance generator, it can be seen that the output voltage of the working circuit 1 is significantly greater than the output voltage of the power circuit 1 and the phase winding voltage, and since the output of the power circuit 1 and the corresponding phase winding, the corresponding capacitor and the inductor are connected in series for output, in addition to obtaining a direct boost output, if the output voltage of the power circuit 1 is adjusted, it will affect the change of the output voltage value of the working circuit 1.

[0074] The power supply circuit 2 has three control working modes. The first working mode is when the switched reluctance motor operates as a generator. Figure 1 As shown, the input end of the power circuit 2 receives the electric energy from the output end of the working circuit 1, that is, the electric energy generated by the switched reluctance motor is used as the input power of the power circuit 2. In addition to outputting the excitation power of the switched reluctance generator, the power circuit 2 also charges the battery B. In this working mode, the eighth switch tube S8 maintains the off state, and the sixth switch tube S6 and the seventh switch tube S7 work in the PWM mode. The switching logic timing is shown in the attached figure. Figure 5As shown, GS6 and GS7 refer to the driving signals of the sixth switch tube S6 and the seventh switch tube S7 respectively. According to the volt-second balance principle of the fourth inductor L4 charging and discharging in a switching cycle T, it can be obtained that:

[0075]

[0076] In formula (4), U F is the input voltage of power supply circuit 2, i.e., the power generation voltage; U L U is the output voltage of the power circuit 2, which is the excitation voltage when the switched reluctance motor operates as a generator; B is the voltage at terminal B of the battery; α1 is the PWM duty cycle of the sixth switch tube S6; α2 is the PWM duty cycle of the seventh switch tube S7.

[0077] It can be seen from formula (4) that by adjusting the PWM duty ratio of the sixth switch tube S6 and the seventh switch tube S7, the output voltage of the power supply circuit 2 can be adjusted, and the charging voltage of the battery B can also be adjusted in response to the charging needs of the battery B. In this mode, the power supply circuit 2 is used not only as the excitation power supply of the switched reluctance generator, but also as the charging operation of the battery B, thus killing two birds with one stone.

[0078] The second working mode of the power supply circuit 2 is a mode in which electric energy is input to the input end of the power supply circuit 2 and output to the output end of the power supply circuit 2 together with the battery B. In this mode, the switched reluctance motor operates as a motor. The electric energy output by the working circuit 1 is converted from the residual magnetic energy of each phase winding, which naturally cannot satisfy the switched reluctance motor to operate as a motor. The battery B is used as the second power supply to supply power. The seventh switch tube S7 maintains the off state, and the sixth switch tube S6 and the eighth switch tube S8 switch in accordance with the PWM mode. The switching logic sequence is as shown in the attached figure. Figure 6 As shown, GS6 and GS8 refer to the driving signals of the sixth switch tube S6 and the eighth switch tube S8 respectively. According to the volt-second balance principle of the fourth inductor L4 and the fifth inductor L5 charging and discharging in a switching cycle T, it can be obtained that:

[0079]

[0080] In formula (5), α3 is the PWM duty cycle of the eighth switch tube S8.

[0081] It can be seen from formula (5) that by adjusting the PWM duty ratio of the sixth switch tube S6 and the eighth switch tube S8, the output voltage of the power supply circuit 2 can be adjusted, that is, the supply voltage of the switched reluctance motor during operation can be adjusted; at the same time, it can be seen that in this mode, the residual energy generated during the operation of the switched reluctance motor can be effectively used as feedback to power itself.

[0082] When the sixth diode D6 is cut off, that is, the residual magnetic energy output voltage of the switched reluctance motor when it is running as a motor is low and cannot enter the power circuit 2, the battery B is used as a power source alone to supply power to the working circuit 1 through the power circuit 2 output. This is the third working mode of the power circuit 2. The sixth switch tube S6 and the seventh switch tube S7 are both kept in the off state, and only the eighth switch tube S8 works in the PWM mode. The switching logic timing is as shown in the attached figure. Figure 7 As shown, GS8 is the driving signal of the eighth switch tube S8, which is equivalent to a traditional BOOST circuit, and the following can be obtained:

[0083]

[0084] It can be seen from formula (6) that by adjusting the PWM duty cycle of the eighth switch tube S8, the power supply voltage value of the switched reluctance motor can be adjusted.

[0085] It can be seen from the operation of the power supply circuit 2 that although the power supply circuit 2 has three switching tubes, in the three modes, at most only two switching tubes are working, among which only one switching tube works in PWM mode in the third working mode, and the overall switching loss is low.

Claims

1. A rail grinding motor system, the motor adopts a switched reluctance motor with a four-phase winding structure, is equipped with an internal combustion engine and a battery, the switched reluctance motor can be used as a motor to connect a grinding device to grind rails as needed, and can also be operated as a generator, driven by an internal combustion engine to generate electrical energy to store energy in the battery, the rail grinding motor system consists of a working circuit and a power supply circuit, and its technical feature is that the output ends of the power supply circuit are connected to the input ends of the working circuit, and the output ends of the working circuit are connected to the input ends of the power supply circuit.

2. According to the rail grinding motor system of claim 1, the working circuit is composed of a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a first phase winding, a second phase winding, a third phase winding, a fourth phase winding, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first inductor, a second inductor, and a third inductor, and its technical feature is that: The anode of the first switch tube is connected to the anode of the second switch tube, the anode of the third switch tube, and the anode of the fourth switch tube, and serves as the positive input terminal of the working circuit. The cathode of the first switch tube is connected to one end of the first phase winding, the cathode of the second switch tube is connected to one end of the second phase winding, the cathode of the third switch tube is connected to one end of the third phase winding, the cathode of the fourth switch tube is connected to one end of the fourth phase winding, the other end of the first phase winding is connected to the other end of the second phase winding, the other end of the third phase winding, the other end of the fourth phase winding, the anode of the first diode, the anode of the second diode, and one end of the second capacitor. The cathode of the first diode is connected to one end of the first capacitor and one end of the first inductor. The other end of the first inductor is connected to the cathode of the second diode, the anode of the fifth switch tube, and the anode of the third diode. anode, a cathode of a third diode is connected to one end of the third capacitor, one end of the fourth capacitor, and one end of the second inductor, the other end of the second inductor is connected to the other end of the second capacitor, the anode of the fourth diode, and one end of the fifth capacitor, the cathode of the fourth diode is connected to the other end of the fourth capacitor and one end of the third inductor, the other end of the third inductor is connected to the other end of the fifth capacitor and the anode of the fifth diode, the cathode of the fifth diode is connected to one end of the sixth capacitor and serves as the positive output terminal of the working circuit, the other end of the sixth capacitor is connected to the cathode of the fifth switch tube, the other end of the first capacitor, and the other end of the third capacitor, and serves as the negative input terminal and the negative output terminal of the working circuit; the first phase winding, the second phase winding, the third phase winding, and the fourth phase winding constitute the four-phase winding of the switched reluctance motor.

3. According to the rail grinding motor system of claim 1, the power supply circuit is composed of a sixth switch tube, a seventh switch tube, an eighth switch tube, a sixth diode, a seventh diode, an eighth diode, a ninth diode, a tenth diode, a seventh capacitor, an eighth capacitor, a fourth inductor, a fifth inductor, and a battery, and its technical feature is that the anode of the sixth diode is connected to the positive output terminal of the working circuit as the positive input terminal of the power supply circuit, the cathode of the sixth diode is connected to the anode of the sixth switch tube and one end of the seventh capacitor, the cathode of the sixth switch tube is connected to the cathode of the seventh diode and one end of the fourth inductor, and the other end of the fourth inductor is connected to the seventh switch tube The anode of the seventh switch tube is connected to the anode of the eighth diode, the cathode of the eighth diode is connected to one end of the fifth inductor and the positive electrode of the battery, the other end of the fifth inductor is connected to the anode of the eighth switch tube and the anode of the tenth diode, the cathode of the tenth diode is connected to the cathode of the ninth diode and one end of the eighth capacitor, and is used as the output positive terminal of the power supply circuit to connect the positive input terminal of the working circuit, the other end of the eighth capacitor is connected to the cathode of the eighth switch tube, the anode of the seventh diode, the other end of the seventh capacitor, and the negative electrode of the battery, and is used as the input negative terminal and output negative terminal of the power supply circuit, and is connected to the input negative terminal and output negative terminal of the working circuit.

4. A rail grinding motor system according to claim 1 and 2, when the switched reluctance motor of the present invention is operated as an electric motor to perform rail grinding operations, its technical features are: The power supply circuit outputs electric energy to supply power to the working circuit. According to the rotor position information of the switched reluctance motor, when the first phase winding needs to be put into operation, the first switch tube and the fifth switch tube are closed and turned on, and the power supply circuit supplies power to the first phase winding through the first switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor outputs energy through the output end of the working circuit alone when there is energy storage; according to the rotor position information, when the first phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the first phase winding drops to zero. It outputs electric energy to the output end of the working circuit through the fifth diode together with the second capacitor, the third inductor, the fifth capacitor, and the power supply circuit, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor through the first switch tube, the first diode, and the third diode together with the first phase winding and the power supply circuit; when the phase current of the first phase winding drops to zero, the first switch tube is turned off, and the operation of the first phase winding ends; According to the rotor position information of the switched reluctance motor, when the second phase winding needs to be put into operation, the second switch tube and the fifth switch tube are closed and turned on, and the power circuit supplies power to the second phase winding through the second switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor outputs energy through the output end of the working circuit alone when there is energy storage; according to the rotor position information, when the second phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the second phase winding drops to zero. It outputs electric energy to the output end of the working circuit through the fifth diode together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor through the second switch tube, the first diode, and the third diode together with the second phase winding and the power circuit; when the phase current of the second phase winding drops to zero, the second switch tube is turned off, and the operation of the second phase winding ends; According to the rotor position information of the switched reluctance motor, when the third phase winding needs to be put into operation, the third switch tube and the fifth switch tube are closed and turned on, and the power circuit supplies power to the third phase winding through the third switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor outputs energy through the output end of the working circuit alone when there is energy storage; according to the rotor position information, when the third phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the third phase winding drops to zero. It outputs electric energy to the output end of the working circuit through the fifth diode together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor through the third switch tube, the first diode, and the third diode together with the third phase winding and the power circuit; when the phase current of the third phase winding drops to zero, the third switch tube is turned off, and the operation of the third phase winding ends; According to the rotor position information of the switched reluctance motor, when the fourth phase winding needs to be put into operation, the fourth switch tube and the fifth switch tube are closed and turned on, and the power circuit supplies power to the fourth phase winding through the fourth switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the sixth capacitor outputs energy through the output end of the working circuit alone when there is energy storage; according to the rotor position information, when the fourth phase winding needs to end its operation, the fifth switch tube is disconnected. At this time, there is still residual energy storage before the phase current of the fourth phase winding drops to zero. It outputs electric energy to the output end of the working circuit together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is charged, and the first inductor also charges the third capacitor together with the fourth phase winding and the power circuit through the fourth switch tube, the first diode, and the third diode; when the phase current of the fourth phase winding drops to zero, the fourth switch tube is turned off, and the operation of the fourth phase winding ends.

5. A rail grinding motor system according to claim 1 and 2, when the internal combustion engine drives the switched reluctance motor to operate as a generator, its technical feature is that the power circuit outputs electrical energy to the working circuit as an excitation power supply, and according to the rotor position information of the switched reluctance motor, when the first phase winding needs to be put into operation, the first switch tube and the fifth switch tube are closed and turned on to enter the first working stage of the first phase winding, i.e., the excitation stage, and the power circuit supplies power to the first phase winding for excitation through the first switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, and the second capacitor, the first inductor, the second inductor, and the third inductor are charged. The output end of the working circuit relies on the sixth capacitor to maintain the output; according to the rotor position information, when the excitation stage of the first phase winding needs to end, the fifth switch tube is disconnected, and the second working stage of the first phase winding, i.e., the power generation stage, is entered. The first phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the first phase winding and the power circuit, charges the third capacitor through the first switch tube, the first diode, and the third diode; when the power generation stage needs to end according to the rotor position information, the first switch tube is disconnected, and the first phase winding ends its work; According to the rotor position information of the switched reluctance motor, when the second phase winding needs to be put into operation, the second switch tube and the fifth switch tube are closed and turned on, and the first working stage of the second phase winding, i.e., the excitation stage, is entered. The power circuit supplies power to the second phase winding for excitation through the second switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, and the second capacitor, the first inductor, the second inductor, and the third inductor are charged. The output end of the working circuit relies on the sixth capacitor to maintain the output; according to the rotor position information, when the excitation stage of the second phase winding needs to be ended, the fifth switch tube is disconnected, and the second working stage of the second phase winding, i.e., the power generation stage, is entered. The second phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the second phase winding and the power circuit, charges the third capacitor through the second switch tube, the first diode, and the third diode; when the power generation stage needs to be ended according to the rotor position information, the second switch tube is disconnected, and the second phase winding ends its operation; According to the rotor position information of the switched reluctance motor, when the third phase winding needs to be put into operation, the third switch tube and the fifth switch tube are closed and turned on, and the first working stage of the third phase winding, i.e., the excitation stage, is entered. The power circuit supplies power to the third phase winding for excitation through the third switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, and the second capacitor, the first inductor, the second inductor, and the third inductor are charged. The output end of the working circuit relies on the sixth capacitor to maintain the output; according to the rotor position information, when the excitation stage of the third phase winding needs to be ended, the fifth switch tube is disconnected, and the second working stage of the third phase winding, i.e., the power generation stage, is entered. The third phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the third phase winding and the power circuit, charges the third capacitor through the third switch tube, the first diode, and the third diode; when the power generation stage needs to be ended according to the rotor position information, the third switch tube is disconnected, and the work of the third phase winding ends; According to the rotor position information of the switched reluctance motor, when the fourth phase winding needs to be put into operation, the fourth switch tube and the fifth switch tube are closed and turned on, and the first working stage of the fourth phase winding, i.e., the excitation stage, is entered. The power circuit supplies power to the fourth phase winding for excitation through the fourth switch tube, the second diode, and the fifth switch tube. At the same time, the first capacitor, the third capacitor, and the fourth capacitor are discharged, the second capacitor, the first inductor, the second inductor, and the third inductor are charged, and the output end of the working circuit relies on the sixth capacitor to maintain the output; according to the rotor position information, when the excitation stage of the fourth phase winding needs to be ended, the fifth switch tube is disconnected, and the second working stage of the fourth phase winding, i.e., the power generation stage, is entered. The fourth phase winding, together with the second capacitor, the third inductor, the fifth capacitor, and the power circuit, outputs electric energy to the output end of the working circuit through the fifth diode, and also charges the sixth capacitor. The first capacitor is also charged, and the first inductor, together with the fourth phase winding and the power circuit, charges the third capacitor through the fourth switch tube, the first diode, and the third diode; when the power generation stage needs to be ended according to the rotor position information, the fourth switch tube is disconnected, and the operation of the fourth phase winding ends.

6. According to a rail grinding motor system described in claims 1 and 3, the power supply circuit has three control working modes, and its technical feature is that the first working mode is when the switched reluctance motor operates as a generator, the input end of the power supply circuit receives electric energy from the output end of the working circuit, and the power supply circuit not only outputs the excitation power supply as the switched reluctance generator, but also charges the battery. In this working mode, the eighth switch tube maintains the off state, the sixth switch tube and the seventh switch tube work in PWM mode, the switching frequencies of the two are the same, the sixth switch tube is turned off when the seventh switch tube is turned on, and the sum of the PWM duty cycles of the two is less than 1.

7. A rail grinding motor system according to claims 1, 3 and 6, whose technical feature is that the second working mode of the power supply circuit is a mode in which electric energy is input into the input end of the power supply circuit and outputs electric energy to the output end of the power supply circuit together with the battery. In this mode, the switched reluctance motor operates as an electric motor, and the electric energy output by the working circuit is converted from the residual magnetic energy of each phase winding. The battery is used as the second power supply for common power supply, the seventh switch tube maintains the off state, the sixth switch tube and the eighth switch tube switch in PWM mode, the two have the same switching frequency, are turned on at the same time, and the PWM duty cycle of the sixth switch tube is greater than the PWM duty cycle of the eighth switch tube.

8. A rail grinding motor system according to claims 1, 3 and 6, wherein the third working mode of the power supply circuit is a mode in which the battery is used alone as a power source to supply power to the working circuit through the output of the power supply circuit, the sixth switch tube and the seventh switch tube are both maintained in the off state, and only the eighth switch tube operates in a PWM mode.

Images