阅读说明：本技术 一种直升压变励磁开关磁阻发电机变流系统 (Direct-boost excitation switched reluctance generator current conversion system ) 是由 孙冠群 宋春伟 张琳涵 于 2019-10-17 设计创作，主要内容包括：一种直升压变励磁开关磁阻发电机变流系统,包括六个开关管、三相绕组、八个电容器、六个二极管、四个电感、直流降压变换器,第一开关管、第二开关管、第三开关管、第四开关管控制开关磁阻发电机各相绕组的励磁和发电工作,以最少开关管直接抬升电压输出,第五开关管和第六开关管调控励磁电压大小,兼顾强化励磁,解决了以最少开关管及低开关应力低损耗下的直接升压、宽范围变励磁电压,以及隔离解耦降压并因应较大功率等级场合,全系器件利用率高、效率高、成本低,适用于各类动力驱动下的中高速开关磁阻发电机系统领域应用。(A direct-boosting excitation switched reluctance generator current transformation system comprises six switch tubes, three-phase windings, eight capacitors, six diodes, four inductors and a direct-current buck converter, wherein the first switch tube, the second switch tube, the third switch tube and the fourth switch tube control excitation and power generation of each phase winding of a switched reluctance generator, the minimum switch tube is used for directly lifting voltage output, the fifth switch tube and the sixth switch tube regulate and control the excitation voltage, excitation is strengthened, direct boosting and wide-range excitation voltage under the condition of minimum switch tubes and low switching stress and low loss are solved, isolation decoupling voltage reduction is achieved, and the system is applicable to the field of medium-high speed switched reluctance generator systems under the drive of various types of power.)

1. The utility model provides a vertical boost becomes excitation switched reluctance generator current transformation system which characterized by includes: the direct current buck converter comprises a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a first phase winding, a second phase winding, a third phase winding, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a first inductor, a second inductor, a third inductor, a fourth inductor and a direct current buck converter, wherein the cathode of the first switching tube is connected with one end of the first phase winding, the cathode of the second switching tube is connected with one end of the second phase winding, the cathode of the third switching tube is connected with one end of the third phase winding, the other end of the first phase winding is connected with the other end of the second phase winding, the other end of the third phase winding, and a direct current buck converter, The anode of the fourth switch tube, one end of the first capacitor, the other end of the first capacitor is connected with one end of the second capacitor, the anode of the first diode, one end of the first inductor, the other end of the second capacitor is connected with one end of the second inductor, one end of the third capacitor and the anode of the second diode, the cathode of the first diode is connected with the other end of the second inductor and one end of the fourth capacitor, the other end of the third capacitor is connected with the anode of the third diode and one end of the third inductor, the cathode of the second diode is connected with the other end of the third inductor and one end of the fifth capacitor, the cathode of the third diode is connected with one end of the sixth capacitor and the input positive end of the DC buck converter, the anode of the first switch tube is connected with the anode of the second switch tube, the anode of the third switch tube, one end of the eighth capacitor and the, the cathode of the fourth switching tube is connected with the other end of the first inductor, the other end of the fourth capacitor, the other end of the fifth capacitor, the other end of the sixth capacitor, the input negative end of the direct-current buck converter, the other end of the eighth capacitor, the cathode of the sixth switching tube, one end of the seventh capacitor and the cathode of the sixth diode, the output positive end of the direct-current buck converter is connected with the anode of the fourth diode and one end of the fourth inductor, the other end of the fourth inductor is connected with the anode of the sixth switching tube and the anode of the fifth diode, the cathode of the fifth diode is connected with the other end of the seventh capacitor and the anode of the fifth switching tube, and the cathode of the fifth switching tube is connected with the anode of the sixth diode and the output negative end;

the fifth switching tube and the sixth switching tube are all full-control power electronic switching devices with anti-parallel diodes; the direct current buck converter is provided with an electromagnetic isolation link; the two ends of the sixth capacitor are power generation output ends; and the two ends of the eighth capacitor are the output ends of the excitation power supply.

2. The control method of the direct-boost variable-excitation switched reluctance generator variable-current system according to claim 1, wherein when the switched reluctance generator is in operation, according to the rotor position information, when the first phase winding needs to be put into operation, the first switching tube and the fourth switching tube are closed, the excitation electric energy from the eighth capacitor charges and excites the first phase winding, according to the rotor position information, the fourth switching tube is opened when the excitation phase is finished, the power generation phase is started, the first switching tube is opened when the power generation phase is finished according to the rotor position information, and the first phase winding is finished;

when the second phase winding and the third phase winding need to be put into operation, the working mode is the same as that of the first phase winding, wherein the second switching tube and the third switching tube correspond to the first switching tube, and other devices are shared;

when the switched reluctance generator operates, the fifth switching tube and the sixth switching tube work according to a PWM mode, and the switching control method comprises the following steps: the switching period, the frequency and the duty ratio of the fifth switching tube and the sixth switching tube are the same, the sixth switching tube lags behind the fifth switching tube by a half period, and the duty ratios of the fifth switching tube and the sixth switching tube are less than 0.5.

Technical Field

The invention relates to the field of switched reluctance motor systems, in particular to a few-switch self-excited switched reluctance generator current transformation system which directly increases voltage output and has adjustable excitation voltage and a control method thereof.

Background

The rotor of the switched reluctance motor has no winding and no conducting bar, and the stator winding is formed by winding salient poles in a concentrated manner, so that the switched reluctance motor has the advantages of simple body structure, low cost, convenience in manufacturing and wide application prospect.

At present, a small amount of applications of a switched reluctance motor appear in some fields, and a switched reluctance generator is relatively less in application, so that in view of the characteristics of the switched reluctance motor, the switched reluctance motor must supply power to each phase winding in different time intervals in operation according to the relative position relationship between a stator and a rotor, and the switched reluctance motor is used as a generator, firstly needs a power supply to supply power and excite, and then generates power to output, so that the requirement on a variable current system of the switched reluctance motor is extremely high in operation, and the variable current system containing each phase winding can be said to be the heart of the switched reluctance generator system.

In view of the fact that the structure and operation characteristics of the switched reluctance generator are completely different from those of other main-flow motors, a current transformation system of the switched reluctance generator is a brand-new field, the development of the field is slow at present, and the traditional excitation and power generation modes have obvious defects.

Like other generators, in most cases, the electric energy generated by the switched reluctance generator needs to be further boosted by the added boosting device and the control system thereof and then provided to a load or incorporated into a power grid, so that if a converter of the switched reluctance generator can directly boost the voltage while exciting and generating, great significance is necessary, and some existing direct boosting devices need more switching tubes.

In the field of switched reluctance generator systems, attention is paid to MPPT (maximum power point tracking) control at present, because the problem of generating efficiency is directly related, the application expansion of the switched reluctance generator is further influenced, the traditional switch angle control is difficult to meet the requirement of high performance, the chopping of the winding current in the excitation stage is only limited in low-speed occasions, therefore, more control variables are needed for development, the power generation efficiency and efficiency are greatly influenced by the magnitude of the excitation voltage, and in addition, the so-called excitation enhancement function is said in the industry, if the excitation voltage can be used as a variable and the strengthening excitation is taken into consideration, the capability of the switched reluctance generator system for realizing better requirements can be enhanced, however, most of the current switched reluctance generator systems cannot realize variable excitation voltage control, or some of them can only realize intermittent adjustment or narrow-range continuous adjustment of the excitation voltage.

The converter system can not be separated from the power electronic switch tube, and the switching loss of the switch tube is of great importance, except for the popular soft switch control in the industry, in fact, the less the number of the switch tubes, the direct reduction of the control burden on the switch tubes is necessary, under the same function, the less the using amount of the switch tubes is, the total loss is naturally low, the generating efficiency is naturally high, the whole reliability is improved, the cost is reduced, in addition, the smaller the voltage stress during the switching action is, the relative loss is inevitably low, the reliability is also high, and therefore, the minimum number of the switch tubes, the low switching stress and the like are the key points of the development of the converter system.

In the current switched reluctance generator converter system industry, a large number of power electronic system structures are often included, and the power electronic system structures do not work frequently in the system operation but only work under extreme conditions, for example, a charging circuit is arranged when a storage battery is used as an excitation power supply, so that the volume weight and the cost are increased, the flexibility and the reliability are reduced, and the average utilization rate of devices is reduced because more switching tubes are inevitably needed, so that the utilization rate of various devices of the switched reluctance generator converter system is also an important problem, and especially, the cost problem which is particularly concerned by a owner in the application expansion of the switched reluctance generator is considered, which is particularly important.

Disclosure of Invention

According to the background technology, the invention provides the switched reluctance generator converter system which directly raises the power generation voltage by depending on the excitation and power generation processes, changes the excitation voltage in a wide range in a self-excitation type after isolation and decoupling, has the least quantity of switching tubes, has low switching stress, high loss and low efficiency, can give consideration to the strong excitation, is simple to control, has low cost and high utilization rate of devices, and is suitable for the application in the field of medium and high speed switched reluctance generator systems under the drive of various powers.

The technical scheme of the invention is as follows:

the utility model provides a vertical boost becomes excitation switched reluctance generator current transformation system which characterized by includes: the direct current buck converter comprises a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a first phase winding, a second phase winding, a third phase winding, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a first inductor, a second inductor, a third inductor, a fourth inductor and a direct current buck converter, wherein the cathode of the first switching tube is connected with one end of the first phase winding, the cathode of the second switching tube is connected with one end of the second phase winding, the cathode of the third switching tube is connected with one end of the third phase winding, the other end of the first phase winding is connected with the other end of the second phase winding, the other end of the third phase winding, and a direct current buck converter, The anode of the fourth switch tube, one end of the first capacitor, the other end of the first capacitor is connected with one end of the second capacitor, the anode of the first diode, one end of the first inductor, the other end of the second capacitor is connected with one end of the second inductor, one end of the third capacitor and the anode of the second diode, the cathode of the first diode is connected with the other end of the second inductor and one end of the fourth capacitor, the other end of the third capacitor is connected with the anode of the third diode and one end of the third inductor, the cathode of the second diode is connected with the other end of the third inductor and one end of the fifth capacitor, the cathode of the third diode is connected with one end of the sixth capacitor and the input positive end of the DC buck converter, the anode of the first switch tube is connected with the anode of the second switch tube, the anode of the third switch tube, one end of the eighth capacitor and the, the cathode of the fourth switching tube is connected with the other end of the first inductor, the other end of the fourth capacitor, the other end of the fifth capacitor, the other end of the sixth capacitor, the input negative end of the direct-current buck converter, the other end of the eighth capacitor, the cathode of the sixth switching tube, one end of the seventh capacitor and the cathode of the sixth diode, the output positive end of the direct-current buck converter is connected with the anode of the fourth diode and one end of the fourth inductor, the other end of the fourth inductor is connected with the anode of the sixth switching tube and the anode of the fifth diode, the cathode of the fifth diode is connected with the other end of the seventh capacitor and the anode of the fifth switching tube, and the cathode of the fifth switching tube is connected with the anode of the sixth diode and the output negative end;

the fifth switching tube and the sixth switching tube are all full-control power electronic switching devices with anti-parallel diodes; the direct current buck converter is provided with an electromagnetic isolation link; the two ends of the sixth capacitor are power generation output ends; and the two ends of the eighth capacitor are the output ends of the excitation power supply.

A control method of a direct-boost variable-excitation switched reluctance generator variable-current system is characterized in that when a first phase winding needs to be put into operation according to rotor position information in the operation of a switched reluctance generator, a first switch tube and a fourth switch tube are closed, excitation electric energy from an eighth capacitor charges and excites the first phase winding, the fourth switch tube is disconnected when an excitation stage is finished according to the rotor position information, a power generation stage is started, the first switch tube is disconnected when the power generation stage is finished according to the rotor position information, and the first phase winding is finished;

when the second phase winding and the third phase winding need to be put into operation, the working mode is the same as that of the first phase winding, wherein the second switching tube and the third switching tube correspond to the first switching tube, and other devices are common:

when the switched reluctance generator operates, the fifth switching tube and the sixth switching tube work according to a PWM mode, and the switching control method comprises the following steps: the switching period, the frequency and the duty ratio of the fifth switching tube and the sixth switching tube are the same, the sixth switching tube lags behind the fifth switching tube by a half period, and the duty ratios of the fifth switching tube and the sixth switching tube are less than 0.5.

The invention has the following main technical effects:

(1) the invention directly outputs high-voltage direct current in excitation and power generation operation, although the output voltage is obviously higher than the excitation voltage only in the power generation stage, the time occupied by the excitation stage is smaller than the time occupied by the power generation stage in the work of one period of each phase winding in consideration of the operation principle of the switched reluctance generator, so that the average voltage of the power generation output end can still be obviously higher than the excitation voltage input by an excitation power supply, and the larger the excitation voltage is, the larger the power generation voltage at the power generation output end is.

(2) The excitation and power generation operation loop only needs one switching tube for each phase winding except one common switching tube, is a minimum switching tube type converter circuit, and only needs N +3 switching tubes for the switched reluctance generator with N phase windings in consideration of a fifth switching tube and a sixth switching tube required by variable excitation voltage, and has small switching stress in operation, so that the converter system has low overall switching loss, high power generation efficiency and low cost.

(3) The utilization rate of various devices of the current transformation system circuit is high, for the excitation and power generation work of the phase winding, except that the switching tube connected with each phase winding in series is closed when the phase winding works, other devices are all common when the phase winding works, and the devices required when the excitation voltage is changed are needed, because the change of the excitation voltage must run in real time to work, and the automatic charging system with the storage battery is not needed to be put into work only under extreme conditions, the utilization rate of the devices on the structure of the current transformation system circuit is high, and the defects that the excitation voltage cannot be changed by other excitation, the occupied area of the storage battery is large and the like when the storage battery is used do not exist.

(4) The high-frequency PWM works in cooperation with the fifth switch tube and the sixth switch tube, the regulation mode is simple, the excitation voltage output in a wide range can be converted, namely, a variable is added to a switched reluctance generator system except for a switching angle and excitation current chopping, and a high-performance regulation mode is realized.

(5) The invention relates to a self-excitation mode, wherein the generated and output electric energy is used as the input power of a variable excitation loop, which belongs to the self-excitation mode, but is different from the traditional self-excitation mode, the output of the excitation power is decoupled with the generated output, a DC step-down converter with an isolation function is added in the middle, and the invention can be adapted to the situation of a switched reluctance generator system with larger power grade due to the isolation measure except that the generated voltage of the generating output end of the invention is always smaller than the generated voltage and the variable excitation voltage needs smaller input voltage to reduce the voltage.

Drawings

Fig. 1 is a circuit structure diagram of a converter system of a direct-boost excitation switched reluctance generator according to the present invention.

Detailed Description

A direct-current boost variable-excitation switched reluctance generator converter system of this embodiment is shown in fig. 1, and includes a first switching tube V1, a second switching tube V2, a third switching tube V3, a fourth switching tube V4, a fifth switching tube V5, a sixth switching tube V6, a first phase winding M, a second phase winding N, a third phase winding P, 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 seventh capacitor C7, an eighth capacitor C8, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a first inductor L1, a second diode L2, a third inductor L2, a fourth inductor L2, a first direct-current transformer L2, a first cathode of the first switching tube V2 is connected to a first negative pole of the first switching tube V2, the cathode of the third switching tube V3 is connected with one end of the third phase winding P, the other end of the first phase winding M is connected with the other end of the second phase winding N, the other end of the third phase winding P, the anode of the fourth switching tube V4 and one end of the first capacitor C1, the other end of the first capacitor C1 is connected with one end of the second capacitor C2, the anode of the first diode D1 and one end of the first inductor L1, the other end of the second capacitor C2 is connected with one end of the second inductor L2, one end of the third capacitor C3 and the anode of the second diode D2, the cathode of the first diode D1 is connected with the other end of the second inductor L2 and one end of the fourth capacitor C6329, the other end of the third capacitor C3 is connected with the anode of the third diode D3 and one end of the third inductor L3, the cathode of the second diode D2 is connected with the other end of the third inductor L3 and one end of the fifth capacitor, the anode of the first switch tube V1 is connected with the anode of the second switch tube V2, the anode of the third switch tube V3, one end of an eighth capacitor C8 and the cathode of a fourth diode D4, the cathode of the fourth switch tube V4 is connected with the other end of a first inductor L1, the other end of a fourth capacitor C4, the other end of a fifth capacitor C5, the other end of a sixth capacitor C6 and the input negative end of the DC buck converter, the other end of the eighth capacitor C8, the cathode of a sixth switching tube V6, one end of a seventh capacitor C7 and the cathode of a sixth diode D6, the positive output end of the DC buck converter is connected with the anode of the fourth diode D4 and one end of a fourth inductor L4, the other end of the fourth inductor L4 is connected with the anode of the sixth switching tube V6 and the anode of a fifth diode D5, the cathode of a fifth diode D5 is connected with the other end of the seventh capacitor C7 and the anode of a fifth switching tube V5, and the cathode of the fifth switching tube V5 is connected with the anode of the sixth diode D6 and the negative output end of the DC buck converter;

the fifth switch tube V5 and the sixth switch tube V6 are all full-control power electronic switch devices with anti-parallel diodes; the direct current buck converter is provided with an electromagnetic isolation link, and the buck amplitude is seven times, namely the voltage of an output end is one seventh of that of an input end; the two ends of the sixth capacitor C6 are power generation output ends; and an excitation power supply output end is arranged at two ends of the eighth capacitor C8.

In the control method of the direct-voltage boost variable excitation switched reluctance generator variable flow system of the embodiment, when a first phase winding M needs to be put into operation according to rotor position information during operation of the switched reluctance generator, a first switching tube V1 and a fourth switching tube V4 are closed, excitation electric energy from an eighth capacitor C8 charges and excites the first phase winding M, an excitation stage is started, meanwhile, a first capacitor C1 charges a first inductor L1, a first capacitor C1 and a fourth capacitor C4 charge a second inductor L2 and a second capacitor C2, and the first capacitor C1 and a fifth capacitor C5 charge a third inductor L3 and a third capacitor C3; according to the rotor position information, the fourth switch tube V4 is disconnected when the excitation phase is finished, the first switch tube V1 is kept in a closed state, and the power generation phase is entered, the stored energy of the first phase winding M and the excitation power supply are output to the power generation output end together, specifically, the first phase winding M is connected in series with the excitation power supply and is charged to the first capacitor C1 and the fourth capacitor C4 through the first diode D1, the first inductor L1 is charged to the fourth capacitor C4 through the first diode D1, the first phase winding M is connected in series with the excitation power supply, the second capacitor C2 is charged to the fifth capacitor C5 through the second diode D2 and the first capacitor C1, the first phase winding M is connected in series with the excitation power supply, the first phase winding M and the second inductor L2 are connected in series through the first diode D1, the second diode D2 and the first capacitor C1 and are charged to the fifth capacitor C5 through the first diode C638, the excitation power supply, the first phase winding M and the third capacitor C3 are connected, The third diode D3 charges the sixth capacitor C6 and outputs electric energy to the power generation output end, the excitation power supply, the first phase winding M, the second capacitor C2 and the third inductor L3 are connected in series and charge the sixth capacitor C6 through the first capacitor C1, the second diode D2 and the third diode D3 and output electric energy to the power generation output end, and therefore, the voltage at the time of the power generation output end, namely the two sides of the sixth capacitor C6 is obviously higher relative to the excitation power supply; disconnecting the first switching tube V1 when the power generation phase is finished according to the rotor position information, and finishing the work of the first phase winding M;

according to the position information of the rotor, when a second phase winding N and a third phase winding P need to be put into operation, the operation mode is the same as that of the first phase winding M, and all the other devices are shared except that a second switching tube V2 and a third switching tube V3 which correspond to the second phase winding N and the third phase winding P respectively correspond to a first switching tube V1;

when the switched reluctance generator operates, the fifth switching tube V5 and the sixth switching tube V6 work according to a PWM mode, and the switching control method comprises the following steps: the switching period, frequency and duty ratio of the fifth switching tube V5 and the sixth switching tube V6 are the same, but the closing phase point of the sixth switching tube V6 lags behind the half period of the fifth switching tube V5, namely 180 degrees, and the duty ratios of the fifth switching tube V5 and the sixth switching tube V6 are less than 0.5.

The structure and the control method of the invention can be seen that for the switched reluctance generator with non-three-phase windings, the control method is the same without increasing or deleting the phase windings and the switching tubes connected in series, so that the invention is in the protection range for the switched reluctance generator with any phase winding number.