Three-level converter based on IGCT mixed connection and modulation method

Abstract

The invention discloses a three-level converter based on IGCT mixed connection and a modulation method. Comprising three single-phase modules which are connected in parallel, and each single-phase module comprises a first semiconductor power switch, a second semiconductor power switch, a third semiconductor power switch, a fourth semiconductor power switch, a fifth semiconductor power switch, a sixth semiconductor power switch, a first capacitor and a second capacitor. The second semiconductor power switch and the third semiconductor power switch are different from the other four semiconductor power switches and are provided with different types of semiconductor power switches, so that on the premise of ensuring that the power consumption of the IGCT is reduced, the working frequencies of the phase voltage and the line voltage output by the converter are improved through an IGBT or SiC high-frequency transistor; and the demand on a filter circuit is reduced. According to the embodiment of the invention, the low conduction loss characteristic of the IGCT device is reserved, the cost of the converter is also considered, the equivalent switching frequency of the output voltage of the converter is improved, and the technical effects of reducing the design difficulty and the size of a filter are realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of converter control, and particularly relates to a three-level converter based on IGCT hybrid connection and a modulation method. BACKGROUND

[0002] The active neutral point clamped three-level converter (ANPC) topology is widely applied to large-capacity pumped storage unit frequency converters and fan converters. The AC / DC power conversion link of the pumped storage unit frequency converter and the fan converter adopts the active neutral point clamped three-level converter.

[0003] The active neutral point clamped (ANPC) converter full-controlled power device can select the integrated gate-commutated thyristor (IGCT) full-controlled device. The IGCT has a low on-state voltage drop, higher reliability and lower cost, which becomes one of the ideal choices of high-voltage large-capacity power electronic converter switching devices. The IGCT device has large turn-off loss and low switching frequency, which is not suitable for high-frequency application scenarios, and the switching frequency is generally not more than 1000 Hz. In order to improve the output voltage quality of the converter, a large filter device is usually configured on the AC side.

[0004] In order to reduce the switching loss of the IGCT power device and improve the equivalent switching frequency of the converter output voltage, by adjusting the on-state current and switching times of the switching device, the unbalance problem of the switching device can be alleviated to a certain extent, and the equivalent switching of the converter output voltage is improved, but a large filter device is still needed. SUMMARY

[0005] The embodiment of the application provides a three-level converter based on IGCT hybrid connection and a modulation method, which can control part of the semiconductor power switches to work in a high-frequency range, so that the output frequency of the phase voltage and the line voltage of the converter is improved, the switching loss of the IGCT power device is reduced, the equivalent switching frequency of the converter output voltage is improved, and the problem of low switching frequency is solved.

[0006] In a first aspect, the embodiments of the present application provide a three-level converter based on IGCT hybrid connection, comprising three single-phase modules connected in parallel, each single-phase module comprising: a first semiconductor power switch, a second semiconductor power switch, a third semiconductor power switch, a fourth semiconductor power switch, a fifth semiconductor power switch, a sixth semiconductor power switch, a first capacitor and a second capacitor; the first semiconductor power switch, the second semiconductor power switch, the third semiconductor power switch and the fourth semiconductor power switch are connected in sequence; a series branch of the second semiconductor power switch and the third semiconductor power switch is connected in parallel with a series branch of the fifth semiconductor power switch and the sixth semiconductor power switch, the second semiconductor power switch and the third semiconductor power switch are first type semiconductor power switches, the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are second type semiconductor power switches, one of the first type semiconductor power switch and the second type semiconductor power switch is an integrated gate-commutated thyristor, and the other is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor; the first capacitor is connected across the first semiconductor power switch and the fifth semiconductor power switch; the second capacitor is connected across the sixth semiconductor power switch and the fourth semiconductor power switch, and the first capacitor and the second capacitor are connected in series.

[0007] In a possible implementation, the first type semiconductor power switch corresponding to the second semiconductor power switch and the third semiconductor power switch is the insulated gate bipolar transistor or the silicon carbide junction field effect transistor, the second type semiconductor power switch corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is the integrated gate-commutated thyristor; the negative electrode of the first semiconductor power switch is electrically connected to the positive electrode of the first capacitor, the positive electrode of the first semiconductor power switch is electrically connected to the first end of the second semiconductor power switch and the negative electrode of the fifth semiconductor power switch; the second end of the second semiconductor power switch is electrically connected to the first end of the third semiconductor power switch as an output end of the single-phase module; the second end of the third semiconductor power switch is electrically connected to the negative electrode of the fourth semiconductor power switch and the positive electrode of the sixth semiconductor power switch; the positive electrode of the fourth semiconductor power switch is electrically connected to the negative electrode of the second capacitor; the positive electrode of the fifth semiconductor power switch is electrically connected to the negative electrode of the sixth semiconductor power switch, the negative electrode of the first capacitor and the positive electrode of the second capacitor.

[0008] In a possible implementation, the first type semiconductor power switch corresponding to the second semiconductor power switch and the third semiconductor power switch is the integrated gate-commutated thyristor, and the second type semiconductor power switch corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, and the sixth semiconductor power switch is the insulated gate bipolar transistor or the silicon carbide junction field effect transistor; the first end of the first semiconductor power switch is electrically connected with the positive electrode of the first capacitor, the second end of the first semiconductor power switch is electrically connected with the negative electrode of the second semiconductor power switch and the first end of the fifth semiconductor power switch; the positive electrode of the second semiconductor power switch is electrically connected with the negative electrode of the third semiconductor power switch as the output end of the single-phase module; the positive electrode of the third semiconductor power switch is electrically connected with the first end of the fourth semiconductor power switch and the second end of the sixth semiconductor power switch; the second end of the fourth semiconductor power switch is electrically connected with the negative electrode of the second capacitor; and the second end of the fifth semiconductor power switch is electrically connected with the first end of the sixth semiconductor power switch, the negative electrode of the first capacitor, and the positive electrode of the second capacitor.

[0009] In a possible implementation, each semiconductor power switch in the single-phase module is anti-parallel connected with a diode.

[0010] In a second aspect, an embodiment of the present application provides a modulation method of a three-level converter based on IGCT hybrid connection, applied to the three-level converter based on IGCT hybrid connection as any of the first aspect, comprising: determining a target modulation strategy corresponding to the converter in the case of determining the specific types of the first type semiconductor power switch and the second type semiconductor power switch; determining target switch state information corresponding to the converter according to the target modulation strategy, the target state information being information of different switch state combinations of the first semiconductor power switch, the second semiconductor power switch, the third semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, and the sixth semiconductor power switch; and adjusting the output frequency of the semiconductor power switches in the converter by using the target state information and a PWM signal wave, so as to make the converter output a high-frequency electric signal.

[0011] In a possible implementation, the determining the target modulation strategy of the converter according to the specific types of the first type semiconductor power switch and the second type semiconductor power switch comprises: in a case where the first type semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, and the second type semiconductor power switch is an integrated gate-commutated thyristor, determining that the target modulation strategy of the converter is a first modulation strategy; in a case where the first type semiconductor power switch is an integrated gate-commutated thyristor, and the second type semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, determining that the target modulation strategy of the converter is a second modulation strategy.

[0012] In a possible implementation, the determining the target modulation strategy of the converter according to the specific types of the first type semiconductor power switch and the second type semiconductor power switch comprises: in a case where the first type semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, and the second type semiconductor power switch is an integrated gate-commutated thyristor, determining that the target modulation strategy of the converter is a first modulation strategy; in a case where the first type semiconductor power switch is an integrated gate-commutated thyristor, and the second type semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, determining that the target modulation strategy of the converter is a second modulation strategy.

[0013] In a possible implementation, the adjusting the output frequency of the semiconductor power switch in the converter according to the target state information and the PWM signal wave comprises: according to the first switch state information, setting a high-frequency threshold range corresponding to the second semiconductor power switch and the third semiconductor power switch in the converter, and setting a base-frequency threshold range corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, and the sixth semiconductor power switch, frequency values in the base-frequency threshold range are lower than frequency values in the high-frequency threshold range; or, according to the second switch state information, setting the low-frequency threshold range corresponding to the second semiconductor power switch and the third semiconductor power switch in the converter, and setting the high-frequency threshold range corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, and the sixth semiconductor power switch; and adjusting the output frequency of the semiconductor power switch in the converter according to the PWM signal wave and the frequency threshold range.

[0014] In one possible implementation, the adjusting the output frequency of the semiconductor power switches in the converter using the PWM signal wave and the frequency threshold ranges includes: in a case that the PWM signal wave is greater than zero, using the first switch state information to control the first semiconductor power switch and the sixth semiconductor power switch to remain in a conducting state, to control the fourth semiconductor power switch and the fifth semiconductor power switch to remain in a non-conducting state, to control the output frequency of the second semiconductor power switch and the third semiconductor power switch to be within the high frequency threshold range, and to control the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch to be within the fundamental frequency threshold range; in a case that the PWM signal wave is less than zero, using the first switch state information to control the first semiconductor power switch and the sixth semiconductor power switch to remain in a non-conducting state, to control the fourth semiconductor power switch and the fifth semiconductor power switch to remain in a conducting state, to control the output frequency of the second semiconductor power switch and the third semiconductor power switch to be within the high frequency threshold range, and to control the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch to be within the fundamental frequency threshold range.

[0015] In one possible implementation, the adjusting the output frequency of the semiconductor power switches in the converter using the PWM signal wave and the frequency threshold ranges includes: in a case that the PWM signal wave is greater than zero, using the second switch state information to control the second semiconductor power switch to remain in a conducting state, to control the third semiconductor power switch to remain in a non-conducting state, to control the output frequency of the second semiconductor power switch and the third semiconductor power switch to be within the fundamental frequency threshold range, and to control the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, the sixth semiconductor power switch and the single-phase module to be within the high frequency threshold range; in a case that the PWM signal wave is less than zero, using the second switch state information to control the second semiconductor power switch to remain in a non-conducting state, to control the third semiconductor power switch to remain in a conducting state, to control the output frequency of the second semiconductor power switch and the third semiconductor power switch to be within the fundamental frequency threshold range, and to control the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, the sixth semiconductor power switch and the single-phase module to be within the high frequency threshold range.

[0016] The three-level converter based on IGCT mixed connection and the modulation method provided by the embodiment of the application, the converter comprises three single-phase modules connected in parallel, and each single-phase module comprises a first semiconductor power switch, a second semiconductor power switch, a third semiconductor power switch, a fourth semiconductor power switch, a fifth semiconductor power switch, a sixth semiconductor power switch, a first capacitor and a second capacitor; the second semiconductor power switch and the third semiconductor power switch are first-type semiconductor power switches, the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are second-type semiconductor power switches, one of the first-type semiconductor power switch and the second-type semiconductor power switch is an integrated gate-commutated thyristor, and the other is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor; different types of semiconductor power switches are arranged for the second semiconductor power switch and the third semiconductor power switch, which are different from the other four semiconductor power switches, so that the operating frequency of the phase voltage and the line voltage output by the converter is increased through the high-frequency transistor of the IGBT or SiC under the premise of ensuring that the IGCT reduces power consumption, thereby reducing the demand for the filter circuit. According to the embodiment of the application, the low-conduction-loss characteristics of the IGCT device are retained, the cost of the converter is considered, the equivalent switching frequency of the output voltage of the converter is improved, and the technical effects of reducing the design difficulty and the size of the filter are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments of the application will be briefly introduced as follows, and other drawings can also be obtained by those of ordinary skill in the art without creative labor on the premise that the drawings are not attached.

[0018] Fig. 1a is a structural schematic diagram of a three-level converter provided in the related art;

[0019] Fig. 1b is a carrier phase-shifted modulation waveform diagram of a three-level converter provided in the related art;

[0020] Fig. 2 is a structural schematic diagram of a three-level converter based on IGCT mixed connection provided by the embodiment of the application;

[0021] Fig. 3 is a structural schematic diagram of another three-level converter based on IGCT mixed connection provided by the embodiment of the application;

[0022] Fig. 4 is a structural schematic diagram of still another three-level converter based on IGCT mixed connection provided by the embodiment of the application;

[0023] Fig. 5is a flowchart of a modulation method of a three-level converter based on IGCT hybrid connection provided by an embodiment of the present application;

[0024] Fig. 6 is a flowchart of another modulation method of a three-level converter based on IGCT hybrid connection provided by an embodiment of the present application;

[0025] Fig. 7 is a waveform diagram of the modulation method of the three-level converter based on IGCT hybrid connection provided by an embodiment of the present application;

[0026] Fig. 8 is a flowchart of still another modulation method of a three-level converter based on IGCT hybrid connection provided by an embodiment of the present application;

[0027] Fig. 9 is a waveform diagram of another modulation method of the three-level converter based on IGCT hybrid connection provided by an embodiment of the present application;

[0028] Fig. 10 is a structural diagram of a three-level converter device based on IGCT hybrid connection provided by an embodiment of the present application. DETAILED DESCRIPTION

[0029] The features and exemplary embodiments of various aspects of the present application will be described below in detail, in order to make the purposes, technical solutions and advantages of the present application more clear and apparent, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, but not to limit the present application. The present application can be implemented without some of these specific details by those skilled in the art. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0030] It should be noted that, in this paper, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the elements defined by the statement "include" do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0031] Fig. 1ais a structural schematic diagram of a three-level converter provided in the related art. Fig. 1b is a carrier phase-shifted modulation waveform diagram of a three-level converter provided in the related art. According to Fig. 1a It can be seen from the provided diagram that the active neutral point clamped (ANPC) converter full-controlled power device can select IGCT full-controlled device, and has an anti-parallel continuous diode. The ANPC three-level converter can output three levels of positive (P), negative (N) and zero (O) through the control of full-controlled switches, and the maximum level size is E. Since the neutral point clamping current has bidirectional flow, the ANPC converter has four zero-level conduction modes, which are denoted as OU1, OU2, OL1 and OL2, respectively. Therefore, the ANPC three-level converter has a total of six output level states, see Table 1 of switch state information. According to Fig. 1b According to the provided diagram, the ANPC three-level converter usually adopts a carrier phase-shifted modulation method, and all power devices operate in a high-frequency working state under this modulation method.

[0032] Table 1 of switch state information

[0033] T1 T2 T3 T4 T5 T6 Supply voltage V Level state 1 1 0 0 0 1 E P 0 1 0 0 1 0 0 OU1 0 1 0 1 1 0 0 OU2 0 0 1 0 0 1 0 OL1 1 0 1 0 0 1 0 OL2 0 0 1 1 1 0 -E N

[0034] In addition to listing the conduction state of each semiconductor power switch (0 represents off, and 1 represents on) in Table 1 of switch state information, the voltage size of line voltage and phase voltage is also shown, and the voltage size of phase voltage and line voltage is used to reflect the high and low of the converter output frequency.

[0035] In order to reduce the switching loss of IGCT power device and improve the equivalent switching frequency of converter output voltage, the commonly used pulse width modulation method of IGCT device midpoint clamped three-level converter is based on carrier layering sinusoidal pulse modulation (Sinusoidal PWM, SPWM) modulation, outer tube fundamental frequency PWM modulation, and inner tube fundamental frequency PWM modulation. These methods can alleviate the imbalance problem of switching devices to a certain extent and improve the equivalent switching of converter output voltage by adjusting the on-state current and switching times of switching devices, but still require large filtering equipment.

[0036] In order to solve the above technical problems, the embodiment of the present application provides a three-level converter based on IGCT hybrid connection and a modulation method. By replacing the IGCT with an IGBT or a SiC transistor, a hybrid three-level converter is obtained. On the basis of maintaining the structure of the IGCT providing low power consumption, part of the semiconductor power switches are replaced with an insulated gate bipolar transistor (IGBT) or a silicon carbide junction field effect transistor (SiC transistor). The working frequency of the IGBT and the SiC transistor is in a high frequency range, so that the phase voltage and the line voltage of the converter are controlled to work in the high frequency range, and a high frequency signal is output, thereby reducing the investment in the post-stage filtering device and bringing advantages for reducing the cost.

[0037] Firstly, the structure of the three-level converter based on IGCT hybrid connection provided by the embodiment of the present application is introduced.

[0038] Fig. 2 is a structural schematic diagram of a three-level converter based on IGCT hybrid connection provided by the embodiment of the present application. As shown in Fig. 2 , the structure of the three-level converter based on IGCT hybrid connection specifically comprises:

[0039] three single-phase modules 10 connected in parallel, the single-phase module 10 comprising a first semiconductor power switch T1, a second semiconductor power switch T2, a third semiconductor power switch T3, a fourth semiconductor power switch T4, a fifth semiconductor power switch T5, a sixth semiconductor power switch T6, a first capacitor C bus1 and a second capacitor C bus2 .

[0040] The first semiconductor power switch T1, the second semiconductor power switch T2, the third semiconductor power switch T3 and the fourth semiconductor power switch T4 are sequentially connected.

[0041] The series branch of the second semiconductor power switch T2 and the third semiconductor power switch T3 is connected in parallel with the series branch of the fifth semiconductor power switch T5 and the sixth semiconductor power switch T6. The second semiconductor power switch T2 and the third semiconductor power switch T3 are first type semiconductor power switches, and the first semiconductor power switch T1, the fourth semiconductor power switch T4, the fifth semiconductor power switch T5 and the sixth semiconductor power switch T6 are second type semiconductor power switches. One of the first type semiconductor power switch and the second type semiconductor power switch is an integrated gate-commutated thyristor (IGCT), and the other is an insulated gate bipolar transistor (IGBT) or a silicon carbide junction field effect transistor (SiC transistor).

[0042] The first capacitor C bus1 has the first semiconductor power switch T1 and the fifth semiconductor power switch T5 connected at both ends.

[0043] The second capacitor C bus2 The sixth semiconductor power switch T6 and the fourth semiconductor power switch T4 are connected to both ends of the second capacitor C bus1 The first capacitor C bus2 is connected in series with the second capacitor C

[0044] The series connection can be understood as the second end of the first semiconductor power switch being connected to the first end of the second semiconductor power switch, the second end of the second semiconductor power switch being connected to the first end of the third semiconductor power switch, and the second end of the third semiconductor power switch being connected to the first end of the fourth semiconductor power switch.

[0045] The parallel connection can be understood as the second end of the fifth semiconductor power switch being connected to the second end of the sixth semiconductor power switch, the first end of the fifth semiconductor power switch being connected to the first end of the second semiconductor power switch, the second end of the second semiconductor power switch being connected to the first end of the third semiconductor power switch, and the second end of the sixth semiconductor power switch being connected to the second end of the third semiconductor power switch.

[0046] The first end of the first capacitor is connected to the first end of the first semiconductor power switch, the second end of the first capacitor is connected to the first end of the second capacitor, the second end of the fifth semiconductor power switch, and the first end of the sixth semiconductor power switch, and the second end of the second capacitor is connected to the second end of the sixth semiconductor power switch and the second end of the fourth semiconductor power switch.

[0047] The IGCT-based hybrid connection structure can be understood as a structure that must contain an IGCT-type low-power thyristor among multiple semiconductor power switches contained in the structure of the converter, and also contains an IGBT or SiC transistor. The circuit with multiple semiconductor power switch structures is referred to as an IGCT-based hybrid connection structure.

[0048] The first type of semiconductor power switch and the second type of semiconductor power switch belong to one of IGCT, IGBT, or SiC transistor. The operating frequency range of IGCT is 0-50 Hz, while the operating frequency range of IGBT and SiC transistor is 200 Hz-20 KHz. This shows that using IGBT or SiC transistor can increase the output frequency of the device, thereby increasing the output frequency of the phase voltage and line voltage. The phase voltage referred to here is the voltage u0, v0, and w0 output by the single-phase module, and the line voltage is the potential difference between adjacent phases.

[0049] According to Fig. 2The provided diagram, the first semiconductor power switch, the fourth semiconductor power switch, the fourth semiconductor power switch and the fifth semiconductor power switch are defined as outer tubes relative to the output signal position of the converter, and the second semiconductor power switch and the third semiconductor power switch are defined as inner tubes. u0, i0 are the phase voltage and phase current output signals.

[0050] According to Fig. 2 The provided diagram, the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are defined as the second type of semiconductor power switch, and the second semiconductor power switch and the third semiconductor power switch are defined as the first type of semiconductor power switch, thereby distinguishing the semiconductor power switches in the low-frequency working mode from the semiconductor power switches in the high-frequency working mode. By setting the switch state information, the conduction state of the semiconductor power switch is adjusted according to the state information, so that the IGCT works in the fundamental frequency range (0-50 Hz), and at the same time, the IGBT or SiC transistor works in the high-frequency range (200 Hz-20 KHz). In order to control the phase voltage and the line voltage to also work in the high-frequency range, when the inner tube selects the IGBT or SiC transistor, the high-frequency signal is output by controlling the conduction of the inner tube; when the inner tube selects the IGCT, the semiconductor power switch in the high-frequency range is controlled to be turned on by changing the conduction state of the semiconductor power switch, thereby also realizing the output of the high-frequency signal of the phase voltage and the line voltage, improving the output frequency of the converter. It is known that the higher the output frequency, the lower the demand for the filter circuit. This achieves the purpose of reducing the filter circuit, reduces the occupied volume and production cost.

[0051] The present application provides a three-level converter based on IGCT mixed connection. By mixing the semiconductor power switches, the second semiconductor power switch and the third semiconductor power switch are used as a type of semiconductor power switch of the inner tube, and the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are used as another type of semiconductor power switch of the outer tube. Under the premise of maintaining the power consumption reduction of IGCT, some semiconductor power switches are replaced by high-frequency IGBT or SiC transistor. By controlling the conduction state of each semiconductor power switch, the semiconductor power switch is kept working in the high-frequency range, so that the output frequency of the phase voltage is a high-frequency signal, thereby achieving the effect of improving the output frequency of the converter and reducing the filter circuit.

[0052] Fig. 3 Another structure diagram of the three-level converter based on IGCT mixed connection provided by the embodiment of the present application. Fig. 3 isFig. 2 The application is described on the basis of the drawings. According to the drawings provided Fig. 3 The structure of the mixed connection type ANPC type three-level converter based on IGCT specifically comprises:

[0053] The first type semiconductor power switch corresponding to the second semiconductor power switch T2 and the third semiconductor power switch T3 is an insulated gate bipolar transistor IGBT or a silicon carbide junction field effect transistor SiC transistor, and the second type semiconductor power switch corresponding to the first semiconductor power switch T1, the fourth semiconductor power switch T4, the fifth semiconductor power switch T5 and the sixth semiconductor power switch T6 is an integrated gate-commutated thyristor IGCT.

[0054] The negative electrode of the first semiconductor power switch T1 is electrically connected with the positive electrode of the first capacitor C bus1 , and the positive electrode of the first semiconductor power switch T1 is electrically connected with the first end of the second semiconductor power switch T2 and the negative electrode of the fifth semiconductor power switch T5.

[0055] The second end of the second semiconductor power switch T2 is electrically connected with the first end of the third semiconductor power switch T3 as the output end of the single-phase module 10.

[0056] The second end of the third semiconductor power switch T3 is electrically connected with the negative electrode of the fourth semiconductor power switch T4 and the positive electrode of the sixth semiconductor power switch T6.

[0057] The positive electrode of the fourth semiconductor power switch T4 is electrically connected with the negative electrode of the second capacitor C bus2 .

[0058] The positive electrode of the fifth semiconductor power switch T5 is electrically connected with the negative electrode of the sixth semiconductor power switch T6, the negative electrode of the first capacitor C bus1 , the positive electrode of the second capacitor C bus2 .

[0059] Further, according to the drawings provided by Fig. 3 , each semiconductor power switch in the single-phase module 10 is reversely connected in parallel with a diode.

[0060] In an example scenario, according to the drawings provided by Fig. 3 , the first semiconductor power switch is reversely connected in parallel with a diode D1, the second semiconductor power switch is reversely connected in parallel with a diode D2, the third semiconductor power switch is reversely connected in parallel with a diode D3, the fourth semiconductor power switch is reversely connected in parallel with a diode D4, the fifth semiconductor power switch is reversely connected in parallel with a diode D5, and the sixth semiconductor power switch is reversely connected in parallel with a diode D6. The current reverse protection is realized by adding the diodes.

[0061] According to the drawings provided by Fig. 3The provided diagram shows that the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch adopt IGCT. The second semiconductor power switch and the third semiconductor power switch can adopt IGBT or SiC transistor, that is, when the second semiconductor power switch adopts IGBT, the third semiconductor power switch can adopt IGBT or SiC transistor, or, when the second semiconductor power switch adopts SiC transistor, the third semiconductor power switch can adopt IGBT or SiC transistor. Further, various combination modes are obtained. The present application focuses on the difference between IGCT and IGBT, so the difference between IGBT and SiC transistor is not limited in the present application. The selection can be made according to the requirements.

[0062] According to Fig. 3 The provided diagram shows that the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch adopt IGCT of base frequency, which belongs to base frequency outer tube, and the working frequency range is 0-50 Hz. The second semiconductor power switch and the third semiconductor power switch adopt IGBT or SiC transistor of high frequency, which belongs to high frequency inner tube, and the working frequency range is 200 Hz-20 KHz. According to the type of the selected semiconductor power switch, the corresponding switch state information is adjusted to obtain switch state information table 2.

[0063] Switch state information table 2

[0064] T1 T2 T3 T4 T5 T6 Supply voltage V Level state 1 1 0 0 0 1 E P 0 1 0 1 1 0 0 OU2 1 0 1 0 0 1 0 OL2 0 0 1 1 1 0 -E N

[0065] According to the switch state information table 2, it can be seen that the switch states of the first semiconductor power switch T1 and the sixth semiconductor power switch T6 are the same, the switch states of the fourth semiconductor power switch T4 and the fifth semiconductor power switch T5 are the same, the switch states of the first semiconductor power switch T1 and the fourth semiconductor power switch T4 are opposite, and the switch states of the second semiconductor power switch T2 and the third semiconductor power switch T3 are opposite. By controlling the second semiconductor power switch and the third semiconductor power switch to work in the high frequency carrier frequency range, and controlling the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch to work in the base frequency carrier frequency range, the output frequency of the phase voltage and the line voltage of the single-phase module can be increased, so as to realize the purpose of increasing the output frequency of the converter, and provide a premise for reducing the rear-end filter circuit.

[0066] Because the first, fourth, fifth, and sixth semiconductor power switches T1, T4, T5, and T6 utilize IGCT power devices and operate at the fundamental frequency, the low conduction loss advantages of IGCT power devices are fully utilized. The second and third semiconductor power switches T2 and T3 utilize IGBTs or SiC transistor power devices suitable for high-frequency switching and operate at a high-frequency carrier frequency, fully utilizing the high switching frequency advantages of IGBTs and SiC transistor power devices. The frequency of the converter phase unit output level is the same as the switching frequency of the second and third semiconductor power switches T2 and T3, thereby increasing the equivalent switching frequency of the output voltage of the single-phase module.

[0067] Through the IGCT hybrid-connected three-level converter provided by the present application, while maintaining the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch as IGCTs, the converter is ensured to operate within the base frequency range, thereby achieving a low-power operation state; at the same time, the second semiconductor power switch and the third semiconductor power switch are replaced with IGBTs or SiC transistors, which operate within the high-frequency range. According to the contents of the set switch state information table, the output frequencies of the phase voltage and line voltage of the converter are controlled to be within the high-frequency range, thereby achieving the effect of increasing the output frequency of the converter, and further effectively reducing the volume and cost of the filter circuit.

[0068] Fig. 4 This is a structural diagram of another three-level converter based on IGCT hybrid connection provided in an embodiment of the present application. Fig. 4 is Fig. 2 Based on the introduction. Fig. 4 The structure of the three-level converter based on IGCT hybrid connection specifically includes:

[0069] The first type semiconductor power switches corresponding to the second semiconductor power switch T2 and the third semiconductor power switch T3 are integrated gate-commutated thyristors IGCT, and the second type semiconductor power switches corresponding to the first semiconductor power switch T1, the fourth semiconductor power switch T4, the fifth semiconductor power switch T5 and the sixth semiconductor power switch T6 are insulated gate bipolar transistors IGBTs or silicon carbide junction field-effect transistors SiC transistors.

[0070] The first terminal of the first semiconductor power switch T1 is connected to the first capacitor C bus1 The positive electrode of the first semiconductor power switch T1 is electrically connected, and the second end of the first semiconductor power switch T1 is electrically connected to the negative electrode of the second semiconductor power switch T2 and the first end of the fifth semiconductor power switch T5.

[0071] The positive pole of the second semiconductor power switch T2 is electrically connected with the negative pole of the third semiconductor power switch T3 as the output terminal of the single-phase module 10.

[0072] The positive pole of the third semiconductor power switch T3 is electrically connected with the first end of the fourth semiconductor power switch T4 and the second end of the sixth semiconductor power switch T6.

[0073] The second end of the fourth semiconductor power switch T4 is electrically connected with the negative pole of the second capacitor C bus2 .

[0074] The second end of the fifth semiconductor power switch T5 is electrically connected with the first end of the sixth semiconductor power switch T6, the negative pole of the first capacitor C bus1 , the positive pole of the second capacitor C bus2 .

[0075] And according to the diagram provided by Fig. 4 , each semiconductor power switch in the single-phase module 10 is anti-parallel with a diode D.

[0076] In an example scenario, according to the diagram provided by Fig. 4 , the first semiconductor power switch is anti-parallel with a diode D1, the second semiconductor power switch is anti-parallel with a diode D2, the third semiconductor power switch is anti-parallel with a diode D3, the fourth semiconductor power switch is anti-parallel with a diode D4, the fifth semiconductor power switch is anti-parallel with a diode D5, and the sixth semiconductor power switch is anti-parallel with a diode D6. Current reverse protection is achieved by adding diodes.

[0077] According to the diagram provided by Fig. 4 , it can be known that the second semiconductor power switch and the third semiconductor power switch adopt IGCT of base frequency, which belongs to base frequency outer tube, and the working frequency range is 0-50Hz. The first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch adopt IGBT or SiC transistor of high frequency, which belongs to high frequency inner tube, and the working frequency range is 200Hz-20KHz. According to the type of the selected semiconductor power switch, the corresponding switch state information is adjusted to obtain the switch state information table 3.

[0078] Switch state information table 3

[0079] Level state [T1] [T2] [CD AT T3] [CD AT T4] [CD AT T5] [CD AT T6] Output voltage P 1 1 0 0 0 1 +Udc / 2 OU2 0 1 0 1 1 0 0 OL2 1 0 1 0 0 1 0 N 0 0 1 1 1 0 -Udc / 2

[0080] According to the switching state information table 3, it can be seen that the switching states of the first semiconductor power switch T1 and the sixth semiconductor power switch T6 are the same, the switching states of the fourth semiconductor power switch T4 and the fifth semiconductor power switch T5 are the same, the switching states of the first semiconductor power switch T1 and the fourth semiconductor power switch T4 are opposite, and the switching states of the second semiconductor power switch T2 and the third semiconductor power switch T3 are opposite. By controlling the second semiconductor power switch and the third semiconductor power switch to work in the base frequency carrier frequency range, and simultaneously controlling the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch to work in the base frequency carrier frequency range, the technical advantages of low conduction loss of the IGCT power device are fully utilized. The first semiconductor power switch T1, the fourth semiconductor power switch T4, the fifth semiconductor power switch T5 and the sixth semiconductor power switch T6 adopt IGBT or SiC transistor power devices suitable for high-frequency switching, and work in the high-frequency carrier frequency range. The technical advantages of high switching frequency of IGBT and SiC transistor power devices are fully utilized. The frequency of the phase unit output level of the converter is the same as the switching frequency of the second semiconductor power switch T2 and the third semiconductor power switch T3, the equivalent switching frequency of the phase unit output voltage is improved, the output frequency of the phase voltage and the line voltage of the single-phase module is improved, and the purpose of improving the output frequency of the converter is achieved, which provides a prerequisite for reducing the size and cost of the filter circuit.

[0081] The three-level converter based on IGCT hybrid connection provided in the application ensures that the second semiconductor power switch and the third semiconductor power switch are IGCTs and work in the base frequency range, realizes a low-power-consumption operating state, simultaneously replaces the first semiconductor power switch and the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch with IGBT or SiC transistors, and works in the high-frequency range. According to the content of the set switching state information table, the output frequency of the phase voltage and the line voltage of the converter is controlled to be in the high-frequency range, and the effect of improving the output frequency of the converter is achieved, and the size and cost of the filter circuit are further effectively reduced.

[0082] Fig. 5 is a flowchart of a three-level converter modulation method based on IGCT hybrid connection provided by an embodiment of the application. According to the diagram provided by the application, Fig. 5 The steps of the modulation method of the three-level converter based on IGCT hybrid connection include the following S501-S503:

[0083] S501, in the case of determining the specific types of the first type semiconductor power switch and the second type semiconductor power switch, determining the target modulation strategy corresponding to the converter.

[0084] The target modulation strategy can be understood as the PWM modulation mode in the case of different types of semiconductor power switches. This application refers to IGCT or IGBT, SiC transistor, and their position settings have outer tube fundamental frequency modulation strategy and inner tube fundamental frequency modulation strategy. That is, the target modulation strategy is divided into first modulation strategy and second modulation strategy, and the first modulation strategy is understood as the outer tube fundamental frequency modulation strategy, and the second modulation strategy is represented as the inner tube fundamental frequency modulation strategy.

[0085] Further, different PWM modulation strategies can be set according to the converter structure corresponding to the type of semiconductor power switch. The target modulation strategy is determined according to the difference between the type of semiconductor power switch and the position. Reference is provided for the PWM modulation mode corresponding to different structures.

[0086] S502, determining the target switch state information corresponding to the converter according to the target modulation strategy, the target state information being the information of different switch state combinations of the first semiconductor power switch, the second semiconductor power switch, the third semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch.

[0087] The target switch state information mentioned here can be understood as the switch state of the semiconductor power switch and the distribution of the output voltage under different modulation strategies, which provides reference data for the output frequency of the phase voltage and line voltage of the converter. The form of the target switch state information mentioned here is not limited, which can be parameter limited relationship data or corresponding relationship table, etc., which is not limited here.

[0088] Further, after selecting the type of semiconductor power switch, the corresponding PWM modulation mode is determined, and then the size of the corresponding phase voltage and line voltage of each semiconductor power switch in the non-conducting state is determined.

[0089] S503, adjusting the output frequency of the semiconductor power switch in the converter by using the target state information and the PWM signal wave, so as to output high-frequency electrical signals by the converter.

[0090] Further, through the circuit structure of the converter and the set target state information, under the control of the sine wave of the PWM signal wave, according to the different conducting states of each semiconductor power switch, the IGCT works in the fundamental frequency range, fully plays the low power consumption role of the IGCT, and at the same time the IGBT or SiC transistor works in the high frequency range, so that the phase voltage and line voltage output by the converter work in the high frequency range, realizes the purpose of improving the output frequency, and provides reference for the cost of less filter circuit.

[0091] The application provides a modulation method of a three-level converter based on IGCT mixed connection, different target modulation strategies are selected according to different types of semiconductor power switches, corresponding target switch state information is limited under different target modulation strategies, the converter is adjusted by referring to the target state information and using a PWM signal wave and a switch state of the semiconductor power switch, so that the output frequency is improved under the condition of combining IGCT and IGBT or SiC transistor, the equivalent switching frequency of the converter output voltage is improved, and the size and cost of the post-stage filtering device are reduced.

[0092] Fig. 6 is a flowchart of another modulation method of a three-level converter based on IGCT mixed connection provided by the application. Fig. 6 is introduced on the basis of the previous embodiment. Fig. 6 According to the provided diagram, the steps of the modulation method of the three-level converter based on IGCT mixed connection further include S601-S606.

[0093] S601, in the case that the first type semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, and the second type semiconductor power switch is an integrated gate-commutated thyristor, the target modulation strategy of the converter is determined as a first modulation strategy.

[0094] S602, in the case that the target modulation strategy is the first modulation strategy, the first switch state information corresponding to the converter is determined.

[0095] S603, according to the first switch state information, the high-frequency threshold range corresponding to the second semiconductor power switch and the third semiconductor power switch in the converter is set, and the fundamental-frequency threshold range corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is set, and the frequency values in the fundamental-frequency threshold range are all lower than the frequency values in the high-frequency threshold range.

[0096] In a possible example scenario, in the case that the first type of semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, a plurality of different converter structures are obtained. At this time, it can be known that the operating frequencies of the second semiconductor power switch and the third semiconductor power switch are in a high frequency range, and belong to inner tube high frequency semiconductor power switches, and the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are IGCTs, and work in a base frequency range of outer tube. We call the first modulation strategy in this working state as an outer tube base frequency modulation strategy, or an inner tube high frequency modulation strategy. According to the corresponding switching state information of the outer tube base frequency modulation strategy or the inner tube high frequency modulation strategy as the first switching state information, the size of the output voltage of each semiconductor power switch in different conduction states is embodied. For example, the first switching state information here can be the content of the switching state information table 2.

[0097] S604, adjusting the output frequency of the semiconductor power switch in the converter by using the PWM signal wave and the frequency threshold range.

[0098] S605, in the case that the PWM signal wave is greater than zero, controlling the first semiconductor power switch and the sixth semiconductor power switch to keep the conduction state by using the first switching state information, controlling the fourth semiconductor power switch and the fifth semiconductor power switch to keep the off state, controlling the output frequency of the second semiconductor power switch and the third semiconductor power switch to be in a high frequency threshold range, and controlling the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch to be in a base frequency threshold range.

[0099] S606, in the case that the PWM signal wave is less than zero, controlling the first semiconductor power switch and the sixth semiconductor power switch to keep the off state by using the first switching state information, controlling the fourth semiconductor power switch and the fifth semiconductor power switch to keep the conduction state, controlling the output frequency of the second semiconductor power switch and the third semiconductor power switch to be in a high frequency threshold range, and controlling the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch to be in a base frequency threshold range.

[0100] In the case of determining the type of the semiconductor power switch of the converter, the state of the semiconductor power switch in the converter is adjusted with reference to the switch state information and the PWM signal wave, so that the inner tube in which the second semiconductor power switch and the third semiconductor power switch are located operates in a high frequency range within a period of the PWM signal wave output, and the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are controlled to operate in a fundamental frequency range, so that the output line voltage and phase voltage are high frequency signals, and the equivalent switching frequency of the output voltage of the converter is improved, and the filter design difficulty and volume can be reduced.

[0101] In a possible example scenario, Fig. 7 is a waveform diagram of a modulation method of a three-level converter based on IGCT mixed connection provided by the embodiment of the application. When the PWM signal wave is greater than 0, refer to Table 2 of switch state information, only use the level state P and OL2, so that the first semiconductor power switch T1 and the sixth semiconductor power switch T6 are always on, and the fourth semiconductor power switch T4 and the fifth semiconductor power switch T5 are always off; when the PWM signal wave is less than 0, refer to Table 2 of switch state information, only use the level state N and OU2, so that the first semiconductor power switch T1 and the sixth semiconductor power switch T6 are always off, and the fourth semiconductor power switch T4 and the fifth semiconductor power switch T5 are always on. The inner tube (the second semiconductor power switch T2 and the third semiconductor power switch T3) in the whole period of the PWM signal wave operates in a high frequency carrier frequency (200Hz-20kHz), so that the output frequency of the phase voltage and the line voltage of the converter is increased. And the outer tube (i.e. the first semiconductor power switch T1, the sixth semiconductor power switch T6, the fourth semiconductor power switch T4, the fifth semiconductor power switch T5) operates in a fundamental frequency (0-50Hz).

[0102] The application changes the type of part of the semiconductor power switch, operates the IGBT or SiC transistor power device in a high frequency range while keeping the low power consumption of the IGCT, retains the low conduction loss characteristic of the IGCT device, takes into account the cost of the converter, improves the equivalent switching frequency of the output voltage of the converter, and reduces the filter design difficulty and volume.

[0103] Fig. 8 is a flowchart of another modulation method of a three-level converter based on IGCT mixed connection provided by the embodiment of the application. Fig. 8 is in Fig. 5 The embodiment is introduced on the basis of the application. According to Fig. 8 the diagram provided by the application, the steps of the modulation method of the three-level converter based on IGCT mixed connection further include S801-S806:

[0104] S801: When the first type semiconductor power switch is an integrated gate commutated thyristor and the second type semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, determine that the target modulation strategy of the converter is a second modulation strategy.

[0105] S802: When the target modulation strategy is the second modulation strategy, determine second switch state information corresponding to the converter.

[0106] S803. Set a low-frequency threshold range corresponding to the second semiconductor power switch and the third semiconductor power switch in the converter according to the second switch state information, and set a high-frequency threshold range corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, and the sixth semiconductor power switch.

[0107] In one possible example scenario, when the second type of semiconductor power switch is an insulated gate bipolar transistor or a silicon carbide junction field-effect transistor, various converter structures are obtained. In this case, it can be seen that the operating frequencies of the second and third semiconductor power switches are within the fundamental frequency range, and are internal-tube fundamental frequency semiconductor power switches. Simultaneously, the first, fourth, fifth, and sixth semiconductor power switches are IGBTs or SiC transistors, and are external transistors operating within the high-frequency range. We refer to the second modulation strategy in this operating state as an internal-tube fundamental frequency modulation strategy or an external-tube high-frequency modulation strategy. The corresponding switch state information under the internal-tube fundamental frequency modulation strategy or the external-tube high-frequency modulation strategy is used as second switch state information, reflecting the magnitude of the output voltage of each semiconductor power switch in different conduction states. The second switch state information can be found in Switch State Information Table 3.

[0108] S804: Regulate the output frequency of the semiconductor power switch in the converter using the PWM signal wave and the frequency threshold range.

[0109] S805. When the PWM signal wave is greater than zero, use the second switch state information to control the second semiconductor power switch to remain in the on state, control the third semiconductor power switch to remain in the off state, control the output frequencies of the second semiconductor power switch and the third semiconductor power switch to be within a fundamental frequency threshold range, and control the output frequencies of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, the sixth semiconductor power switch, and the single-phase module to be within a high frequency threshold range.

[0110] S806, in the case that the PWM signal wave is less than zero, the second semiconductor power switch is controlled to keep off state, the third semiconductor power switch is controlled to keep on state, the output frequency of the second semiconductor power switch and the third semiconductor power switch is controlled to be in the base frequency threshold range, and the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, the sixth semiconductor power switch and the single-phase module is controlled to be in the high frequency threshold range according to the second switch state information.

[0111] In the case that the type of the semiconductor power switch of the converter is determined, the state of the semiconductor power switch in the converter is adjusted according to the switch state information and the PWM signal wave, so that the inner tube in which the second semiconductor power switch and the third semiconductor power switch are located works in the base frequency range in the period of the PWM signal wave output, and the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are controlled to work in the high frequency range, so that the output line voltage and phase voltage are equivalent high frequency signals, and the equivalent switching frequency of the output voltage of the converter is improved, and the filter design difficulty and volume are reduced.

[0112] In a possible example scenario, Fig. 9 is a waveform diagram of another modulation method of the three-level converter based on IGCT mixed connection provided by the embodiment of the application. When the PWM signal wave is greater than 0, refer to the switch state information table 3, only use the level state P and OU2, so that the second semiconductor power switch T2 is always on, and the third semiconductor power switch T3 is always off; when the PWM signal wave is less than 0, refer to the switch state information table 3, only use the level state N and OL2, so that the second semiconductor power switch T2 is always off, and the third semiconductor power switch T3 is always on. The inner tube (the second semiconductor power switch T2 and the fourth, the third semiconductor power switch T3) works in the base frequency (0-50Hz) in the whole period of the PWM signal wave, and the outer tube (i.e. the first semiconductor power switch T1, the sixth semiconductor power switch T6, the fourth semiconductor power switch T4, the fifth semiconductor power switch T5) works in the high frequency carrier frequency (200Hz-20kHz), so that the output frequency of the phase voltage and the line voltage of the converter is increased.

[0113] The application changes the type of part of the semiconductor power switch, keeps the low power consumption of the IGCT, adopts the IGBT or SiC transistor power device to work in the high frequency range, retains the low conduction loss characteristic of the IGCT device, considers the cost of the converter, improves the equivalent switching frequency of the output voltage of the converter, and reduces the filter design difficulty and volume.

[0114] Fig. 10A structure diagram of the three-level converter device based on the IGCT hybrid connection is shown.

[0115] The three-level converter device based on the IGCT hybrid connection can include a processor 1001 and a memory 1002 storing computer program instructions.

[0116] Specifically, the processor 1001 can include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present application.

[0117] The memory 1002 can include a mass storage for data or instructions. By way of example and not limitation, the memory 1002 can include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. The memory 1002 can include removable or non-removable (or fixed) media, where appropriate. The memory 1002 can be internal or external to the integrated gateway disaster recovery device, as appropriate. In certain embodiments, the memory 1002 is non-volatile, solid-state memory.

[0118] The memory can include read-only memory (ROM), random-access memory (RAM), magnetic disk storage mediums, optical storage mediums, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software that, when executed (by one or more processors), is operable to perform operations described with reference to the modulation method of the three-level converter based on the IGCT hybrid connection according to the present application.

[0119] The processor 1001 implements any one of the modulation methods of the three-level converter based on the IGCT hybrid connection in the above embodiments by reading and executing the computer program instructions stored in the memory 1002.

[0120] In one example, the three-level converter device based on the IGCT hybrid connection can further include a communication interface 1003 and a bus 1010. As shown, the processor 1001, the memory 1002, and the communication interface 1003 are connected by the bus 1010 and complete communication with each other. Fig. 10

[0121] ​The communication interface 1003 is mainly used to realize the communication between the modules, devices, units and / or equipment in the embodiments of the present application.

[0122] Bus 1010 includes hardware, software, or both, that couples components of the online data traffic billing device to each other. As an example and not by way of limitation, the bus can include an accelerated graphics port (AGP) or other graphics bus, an enhanced industry standard architecture (EISA) bus, a front-side bus (FSB), a HyperTransport (HT) interconnect, an industry standard architecture (ISA) bus, an infiniband (IB) interconnect, a low pin count (LPC) bus, a memory bus, a microchannel architecture (MCA) bus, a peripheral component interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a serial advanced technology attachment (SATA) bus, a video electronics standards board (VLB) bus, or another suitable bus or a combination of two or more of these. Where appropriate, bus 1010 can include one or more buses. Although the present application is described and illustrated with a particular bus, the present application contemplates any suitable bus or interconnect.

[0123] The IGCT hybrid three-level converter device can perform the online data traffic billing method in the embodiments of the present application based on the currently intercepted spam messages and the messages reported by the user, thereby realizing the combination Fig. 5 to Fig. 9 The modulation method of the IGCT hybrid three-level converter is described.

[0124] In addition, in combination with the modulation method of the IGCT hybrid three-level converter in the above embodiments, the embodiments of the present application can provide a computer storage medium to realize. The computer storage medium has computer program instructions stored thereon; the computer program instructions are executed by the processor to realize any one of the modulation methods of the IGCT hybrid three-level converter in the above embodiments.

[0125] The embodiments of the present application also provide a computer program product, which includes a computer program, and the computer program is executed by the processor to realize any one of the modulation methods of the IGCT hybrid three-level converter in the above embodiments.

[0126] It needs to be clear that the present application is not limited to the specific configurations and processes described above and shown in the drawings. For the sake of brevity, the detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps, after understanding the spirit of the present application.

[0127] The functions noted in the description of the structural block diagrams above can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, functional cards, and the like. When implemented in software, the elements of the present application are program or code segments that are used to perform the required tasks. The program or code segments can be stored in a machine-readable medium, or transmitted through a data signal carried in a carrier wave over a transmission medium or communication link. A "machine-readable medium" includes any medium that can store or transport information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, and the like. The code segments can be downloaded via computer networks such as the Internet, intranets, and the like.

[0128] It is also important to note that the examples described herein can be implemented in a variety of systems, including and / or incorporating software, firmware, hardware, and / or circuitry. Also, the examples described herein are meant to be examples and embodiments of the application only and various changes, modifications and improvements, in addition to those not specifically described, can be made. For example, features described herein can be combined in any combination desired.

[0129] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. Alternatively, computer program implemented steps can be implemented by special purpose logic circuitry, e.g., an FPGA or an ASIC, or by a combination of special purpose logic circuitry and computer hardware. Those skilled in the art will recognize that the examples described herein are not limited to a computer or other programmable data processing apparatus, and that steps of a computer program can be stored, downloaded, or transmitted on a data signal embodied in a carrier wave and / or a memory.

[0130] The above merely describes a specific implementation of the present application. Those skilled in the art can clearly understand the specific working processes of the system, modules and units described above for the convenience and brevity of description, and can refer to the corresponding processes in the foregoing method embodiments, which will not be described herein again. It should be understood that the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A three-level inverter based on IGCT hybrid connection comprising three single-phase modules connected in parallel, characterized in that, The single-phase module comprises a first semiconductor power switch, a second semiconductor power switch, a third semiconductor power switch, a fourth semiconductor power switch, a fifth semiconductor power switch, a sixth semiconductor power switch, a first capacitor and a second capacitor; The first semiconductor power switch, the second semiconductor power switch, the third semiconductor power switch and the fourth semiconductor power switch are sequentially connected in an electric way; The series branch of the second semiconductor power switch and the third semiconductor power switch is connected in parallel with the series branch of the fifth semiconductor power switch and the sixth semiconductor power switch, the second semiconductor power switch and the third semiconductor power switch are first type semiconductor power switches, the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch are second type semiconductor power switches, one of the first type semiconductor power switch and the second type semiconductor power switch is an integrated gate-commutated thyristor, and the other is an insulated gate bipolar transistor or a silicon carbide junction field effect transistor; The first capacitor is connected across the first semiconductor power switch and the fifth semiconductor power switch; The second capacitor is connected across the sixth semiconductor power switch and the fourth semiconductor power switch, and the first capacitor and the second capacitor are connected in series.

2. The IGCT hybrid-based three-level inverter according to claim 1, characterized in that The first type semiconductor power switch corresponding to the second semiconductor power switch and the third semiconductor power switch is the integrated gate-commutated thyristor, and the second type semiconductor power switch corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is the insulated gate bipolar transistor or the silicon carbide junction field effect transistor; The negative electrode of the first semiconductor power switch is connected with the positive electrode of the first capacitor in an electric way, and the positive electrode of the first semiconductor power switch is connected with the first end of the second semiconductor power switch and the negative electrode of the fifth semiconductor power switch in an electric way; The second end of the second semiconductor power switch is connected with the first end of the third semiconductor power switch in an electric way as an output end of the single-phase module; The second end of the third semiconductor power switch is connected with the negative electrode of the fourth semiconductor power switch and the positive electrode of the sixth semiconductor power switch in an electric way; The positive electrode of the fourth semiconductor power switch is connected with the negative electrode of the second capacitor in an electric way; The positive electrode of the fifth semiconductor power switch is connected with the negative electrode of the sixth semiconductor power switch, the negative electrode of the first capacitor and the positive electrode of the second capacitor in an electric way.

3. The IGCT hybrid three-level inverter according to claim 1, characterized in that The first type semiconductor power switch corresponding to the second semiconductor power switch and the third semiconductor power switch is the integrated gate-commutated thyristor, and the second type semiconductor power switch corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is the insulated gate bipolar transistor or the silicon carbide junction field effect transistor; The first end of the first semiconductor power switch is electrically connected with the positive pole of the first capacitor, and the second end of the first semiconductor power switch is electrically connected with the negative pole of the second semiconductor power switch and the first end of the fifth semiconductor power switch; The positive pole of the second semiconductor power switch is electrically connected with the negative pole of the third semiconductor power switch as an output end of the single-phase module; The positive pole of the third semiconductor power switch is electrically connected with the first end of the fourth semiconductor power switch and the second end of the sixth semiconductor power switch; The second end of the fourth semiconductor power switch is electrically connected with the negative pole of the second capacitor; The second end of the fifth semiconductor power switch is electrically connected with the first end of the sixth semiconductor power switch, the negative pole of the first capacitor and the positive pole of the second capacitor.

4. The IGCT hybrid three-level inverter according to claim 1, characterized in that Each semiconductor power switch in the single-phase module is anti-parallel with a diode.

5. A modulation method for an IGCT hybrid three-level inverter, characterized by, The application is applied to the three-level converter based on the IGCT hybrid connection as claimed in any one of claims 1-4, comprising: In the case of determining the specific types of the first type semiconductor power switch and the second type semiconductor power switch, determining the target modulation strategy corresponding to the converter; According to the target modulation strategy, determining the target switch state information corresponding to the converter, the target state information being the information of different switch state combinations of the first semiconductor power switch, the second semiconductor power switch, the third semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch; Using the target state information and the PWM signal wave to adjust the output frequency of the semiconductor power switch in the converter, so as to make the converter output high-frequency electric signal.

6. The modulation method of a three-level inverter based on IGCT hybrid connection according to claim 5, characterized in that, The determination of the target modulation strategy corresponding to the converter in the case of determining the specific types of the first type semiconductor power switch and the second type semiconductor power switch, comprising: In the case of the first type semiconductor power switch being an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, and the second type semiconductor power switch being an integrated gate-commutated thyristor, determining the target modulation strategy of the converter as a first modulation strategy; In the case of the first type semiconductor power switch being an integrated gate-commutated thyristor, and the second type semiconductor power switch being an insulated gate bipolar transistor or a silicon carbide junction field effect transistor, determining the target modulation strategy of the converter as a second modulation strategy.

7. The modulation method of a three-level inverter based on IGCT hybrid connection according to claim 6, characterized in that, The determination of the target switch state information corresponding to the converter according to the target modulation strategy, comprising: In the case of the target modulation strategy being the first modulation strategy, determining the first switch state information corresponding to the converter; In the case of the target modulation strategy being the second modulation strategy, determining the second switch state information corresponding to the converter.

8. The IGCT hybrid three-level inverter modulation method according to claim 7, characterized in that, The adjustment of the output frequency of the semiconductor power switch in the converter using the target state information and the PWM signal wave, comprising: According to the first switch state information, a high frequency threshold range corresponding to the second semiconductor power switch and the third semiconductor power switch in the converter is set, and a base frequency threshold range corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is set, and the frequency values in the base frequency threshold range are all lower than the frequency values in the high frequency threshold range; or, According to the second switch state information, the low frequency threshold range corresponding to the second semiconductor power switch and the third semiconductor power switch in the converter is set, and the high frequency threshold range corresponding to the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is set. The output frequency of the semiconductor power switch in the converter is adjusted by using the PWM signal wave and the frequency threshold range.

9. The IGCT hybrid three-level inverter modulation method according to claim 8, characterized in that, The output frequency of the semiconductor power switch in the converter is adjusted by using the PWM signal wave and the frequency threshold range, including: When the PWM signal wave is greater than zero, the first semiconductor power switch and the sixth semiconductor power switch are controlled to keep on by using the first switch state information, the fourth semiconductor power switch and the fifth semiconductor power switch are controlled to keep off, the output frequency of the second semiconductor power switch and the third semiconductor power switch is controlled to be in the high frequency threshold range, and the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is controlled to be in the base frequency threshold range; When the PWM signal wave is less than zero, the first semiconductor power switch and the sixth semiconductor power switch are controlled to keep off by using the first switch state information, the fourth semiconductor power switch and the fifth semiconductor power switch are controlled to keep on, the output frequency of the second semiconductor power switch and the third semiconductor power switch is controlled to be in the high frequency threshold range, and the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch and the sixth semiconductor power switch is controlled to be in the base frequency threshold range.

10. The modulation method of a three-level inverter based on IGCT hybrid connection according to claim 8, characterized in that, The output frequency of the semiconductor power switch in the converter is adjusted by using the PWM signal wave and the frequency threshold range, including: When the PWM signal wave is greater than zero, the second semiconductor power switch is controlled to keep on by using the second switch state information, the third semiconductor power switch is controlled to keep off, the output frequency of the second semiconductor power switch and the third semiconductor power switch is controlled to be in the base frequency threshold range, and the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, the sixth semiconductor power switch and the single-phase module is controlled to be in the high frequency threshold range; When the PWM signal wave is less than zero, the second semiconductor power switch is controlled to keep off by using the second switch state information, the third semiconductor power switch is controlled to keep on, the output frequency of the second semiconductor power switch and the third semiconductor power switch is controlled to be in the base frequency threshold range, and the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, the sixth semiconductor power switch and the single-phase module is controlled to be in the high frequency threshold range. In the event that the PWM signal is less than zero, the second switch state information is used to control the second semiconductor power switch to remain in an open state, the third semiconductor power switch to remain in a closed state, the output frequency of the second semiconductor power switch and the third semiconductor power switch to be within the base frequency threshold range, and the output frequency of the first semiconductor power switch, the fourth semiconductor power switch, the fifth semiconductor power switch, the sixth semiconductor power switch, and the single-phase module to be within the high frequency threshold range.

Images