H-bridge topological structure, main branch full-control valve, controllable converter and control method

Abstract

The invention provides an H-bridge topological structure, a main branch full-control valve, a controllable converter and a control method, and the H-bridge topological structure comprises an H-bridge branch, an energy consumption branch and a bypass branch. The H-bridge branch comprises a first full-control device, a second full-control device, a first one-way conduction element, a second one-way conduction element and a capacitor. The main branch full-control valve comprises a plurality of H-bridge topological structures, three structural forms of the main branch full-control valve and the controllable current converter are formed on the basis of the H-bridge topological structures, the main branch full-control valve and the controllable current converter comprise bridge arms connected in three-phase power in parallel, and each phase of bridge arm comprises a plurality of valves connected in series; the valve comprises a main branch, a main lightning arrester and an auxiliary branch. The main branch, the main lightning arrester and the auxiliary branch are connected in parallel; the main branch comprises a main branch full-control valve; the auxiliary branch comprises a plurality of high-voltage full-control valves which are connected in series and form a controllable converter for forced commutation when an alternating-current fault occurs, and the controllable converter does not have the problems of overvoltage and commutation failure in an extra-high-voltage scene.

Description

Technical Field

[0001] The present invention belongs to the technical field of direct current power grids, and in particular relates to an H-bridge topology structure, a main branch full-control valve, a controllable converter and a control method. Background Art

[0002] DC engineering construction is mainly based on ±800kV / 8000MW UHV DC transmission projects. The development of ±800kV / 8000MW UHV controllable phase-changing valves has practical application value. However, in the existing technical solution, the main branch full-control valve adopts IGBT (Insulate-Gate Bipolar Transistor) and its buffer components in series to form a parallel lightning arrester to limit the overvoltage when the fault current is shut down. Due to the limitations of the current carrying capacity of the existing fully controlled devices and the capacity of the lightning arrester, the ±800kV controllable phase-changing valve cannot completely use the existing controllable phase-changing converter topology; at the same time, the performance indicators such as voltage and current stress, loss, and valve control complexity of the converter with higher capacity level should be further optimized to fully meet the application requirements of UHV DC projects.

[0003] Therefore, the structure of the existing controllable converter valve is not suitable for ultra-high voltage scenarios, and the controllable converter valve has problems of overvoltage and commutation failure in ultra-high voltage scenarios. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the prior art, in a first aspect, the present invention proposes an H-bridge topology structure, including: an H-bridge branch, an energy consumption branch and a bypass branch; the H-bridge branch includes: a first fully-controlled device, a second fully-controlled device, a first unidirectional conductive element, a second unidirectional conductive element and a capacitor; After the positive electrode of the first fully-controlled device and the first unidirectional conducting element are connected in forward series, the second fully-controlled device and the second unidirectional conducting element are connected in reverse series in sequence; the two ends of the capacitor and the energy-consuming branch after being connected in parallel are respectively connected to the connection point between the first unidirectional conducting element and the second fully-controlled device, and the connection point between the second unidirectional conducting element and the first fully-controlled device.

[0005] Preferably, one of the structures of the energy-consuming branch includes: a resistor and a third fully-controlled device, wherein the positive electrode of the third fully-controlled device is connected in series to one end of the resistor; the negative electrode of the third fully-controlled device is connected to the connection point between the second unidirectional conducting element and the first fully-controlled device, and the other end of the resistor is connected to the connection point between the first unidirectional conducting element and the second fully-controlled device.

[0006] Preferably, another structure of the energy-consuming branch includes: a resistor, a third fully-controlled device and a diode, wherein the positive electrode of the third fully-controlled device is connected to the positive electrode of the diode, and the resistor is connected in parallel with the diode; the negative electrode of the third fully-controlled device is connected to the connection point between the second unidirectional conducting element and the first fully-controlled device, and the negative electrode of the diode is connected to the connection point between the first unidirectional conducting element and the second fully-controlled device.

[0007] Preferably, another structure of the energy-consuming branch comprises: a resistor, a third fully-controlled device and a fuse, the positive electrode of the third fully-controlled device is connected in series to one end of the resistor, the other end of the resistor is connected in series to one end of the fuse, the negative electrode of the third fully-controlled device is connected to the connection point between the second unidirectional conducting element and the first fully-controlled device, and the other end of the fuse is connected to the connection point between the first unidirectional conducting element and the second fully-controlled device.

[0008] Preferably, the first unidirectional conducting element is a diode or a thyristor, and the second unidirectional conducting element is a diode or a thyristor.

[0009] In the second aspect, the present invention application also proposes a main branch full-control valve, including: multiple H-bridge topology structures as described above; the first full-control device, the second full-control device, the first unidirectional conductive element, the second unidirectional conductive element, the capacitor, the energy-consuming branch and the bypass branch in the H-bridge branches in the multiple H-bridge topology structures are connected in series respectively.

[0010] On the third aspect, the present invention application also proposes another main branch fully-controlled valve, comprising: a plurality of the H-bridge topology structures and a plurality of thyristors; after the connection point between the second fully-controlled device and the second unidirectional conducting element in one of the H-bridge topology structures and the connection point between the first fully-controlled device and the first unidirectional conducting element in another of the H-bridge topology structures are connected in series in sequence, a plurality of thyristors in series are connected in parallel as a whole.

[0011] In a fourth aspect, the present invention application also proposes another main branch full-control valve, comprising: a plurality of the H-bridge topology structures; a connection point between a second full-control device and a second unidirectional conducting element in one of the H-bridge topology structures and a connection point between a first full-control device and a first unidirectional conducting element in another of the H-bridge topology structures are connected in series in sequence.

[0012] In a fifth aspect, the present invention application further proposes a controllable converter, comprising: a bridge arm connected in parallel in a three-phase power system, each phase bridge arm comprising: a plurality of valves connected in series; the valves comprising: a main branch, a main lightning arrester, and an auxiliary branch; The main branch, the main lightning arrester and the auxiliary branch are connected in parallel; The main branch includes: the main branch full-control valve; The auxiliary branch includes: a plurality of high-pressure full-control valves connected in series.

[0013] Preferably, the main branch further comprises: a main saturated reactor and a thyristor; The main saturated reactor, the thyristor and the main branch full-control valve are connected in series in a forward direction in sequence.

[0014] Preferably, the converter further comprises: a central controller; the central controller is connected to the first fully-controlled device, the second fully-controlled device, the third fully-controlled device, the capacitor, and the bypass branch in the main branch fully-controlled valve via an optical fiber; When an AC fault occurs, the central controller controls the triggering or shutting down of the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device to implement forced commutation for detecting the voltage of the capacitor.

[0015] In a sixth aspect, the present invention application further proposes a control method for a controllable converter, comprising: using a central controller in the controllable converter to determine an operation mode of the controllable converter based on the actual working condition of the controllable converter, wherein the operation mode includes a conventional commutation mode and / or a controllable commutation mode; When the controllable converter is in the conventional commutation mode, the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device in the main branch fully-controlled valve in the controllable converter are controlled to be in a locked state, and the bypass branch in the main branch fully-controlled valve is controlled to be periodically opened or closed; When the controllable converter is in the normal operating condition of the controllable commutation mode, the first fully-controlled device and the second fully-controlled device are controlled to be synchronously periodically turned on or off, and the third fully-controlled device and the bypass branch are controlled to be in a locked state; When the controllable converter is in the AC fault condition of the controllable commutation mode, the first fully-controlled device and the second fully-controlled device are controlled to be turned off and the bypass branch is locked; when the voltage of the capacitor in the controllable converter is greater than the preset voltage, the energy-consuming branch in the controllable converter is controlled to be turned on to prevent the controllable converter from having overvoltage and / or commutation failure.

[0016] Preferably, when the controllable converter is in the normal operating condition of the controllable commutation mode, controlling the first fully-controlled device and the second fully-controlled device to be synchronously periodically turned on or off, and controlling the third fully-controlled device and the bypass branch to be in a locked state, includes: When the controllable converter is in the normal operating condition of the controllable commutation mode, the voltage of the capacitor in the controllable converter is periodically selected and the voltage is transmitted to the valve in the controllable converter; so that the valve adaptively adjusts the on or off period of the first fully-controlled device and the second fully-controlled device within a preset voltage range according to the voltage.

[0017] In a seventh aspect, the present invention application further proposes an electronic device, comprising: at least one processor and a memory; the memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the control method of a controllable converter is implemented.

[0018] In an eighth aspect, the present application further proposes a readable storage medium having an execution program stored thereon, and when the execution program is executed, the control method of the controllable converter is implemented.

[0019] Compared with the closest prior art, the present invention has the following beneficial effects: An H-bridge topology structure of the present invention comprises: an H-bridge branch, an energy-consuming branch and a bypass branch; the H-bridge branch comprises: a first fully-controlled device, a second fully-controlled device, a first unidirectional conductive element, a second unidirectional conductive element and a capacitor; after the positive electrode of the first fully-controlled device and the first unidirectional conductive element are connected in forward series, the second fully-controlled device is connected in forward series and the second unidirectional conductive element is connected in reverse series in sequence; the two ends of the capacitor and the energy-consuming branch after being connected in parallel are respectively connected to the connection point between the first unidirectional conductive element and the second fully-controlled device, and the connection point between the second unidirectional conductive element and the first fully-controlled device. The H-bridge topology structure can select mature fully-controlled devices for engineering applications, and the structure can achieve controllable shutdown under any current. The energy-consuming branch is set to ensure that the capacitor voltage will not exceed its limit value, thereby avoiding the risk of device overvoltage breakdown. Therefore, the structure of the present invention has an active shutdown function and does not have an overvoltage risk.

[0020] The present invention also proposes a main branch full-control valve of the first structural form, comprising: a plurality of the H-bridge topological structures; the first full-control device, the second full-control device, the first unidirectional conductive element, the second unidirectional conductive element, the capacitor, the energy-consuming branch and the bypass branch in the H-bridge branches in the plurality of the H-bridge topological structures are connected in series respectively. The main branch full-control valve of the second structural form comprises: a plurality of the H-bridge topological structures and a plurality of thyristors; after the connection point of the second full-control device and the second unidirectional conductive element in one H-bridge topological structure and the connection point of the first full-control device and the first unidirectional conductive element in another H-bridge topological structure are connected in series in sequence, the plurality of thyristors connected in series are connected in parallel as a whole. The main branch full-control valve of the third structural form comprises: a plurality of the H-bridge topological structures; the connection point of the second full-control device and the second unidirectional conductive element in one H-bridge topological structure and the connection point of the first full-control device and the first unidirectional conductive element in another H-bridge topological structure are connected in series in sequence. The three structural forms of the main branch full-control valves provided have an active shut-off function, and there is no problem of overvoltage and commutation failure in the main branch full-control valve.

[0021] A controllable converter of the present invention comprises: a bridge arm connected in parallel in three-phase electricity, each phase bridge arm comprises: a plurality of valves connected in series; the valve comprises: a main branch, a main lightning arrester, and an auxiliary branch; the main branch, the main lightning arrester and the auxiliary branch are connected in parallel; the main branch comprises: the main branch full-control valve; the auxiliary branch comprises: a plurality of high-voltage full-control valves connected in series, and the controllable converter realizes forced commutation in the event of an AC fault, so it is suitable for ultra-high voltage scenarios, so that the controllable converter does not have overvoltage and commutation failure problems in ultra-high voltage scenarios.

[0022] A control method for a controllable converter of the present invention comprises: using a central controller in the controllable converter to determine the operation mode of the controllable converter based on the actual working condition of the controllable converter, wherein the operation mode includes a conventional commutation mode and / or a controllable commutation mode; when the controllable converter is in the conventional commutation mode, controlling the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device in the main branch fully-controlled valve in the controllable converter to be in a locked state, and controlling the bypass branch in the main branch fully-controlled valve to be periodically opened or closed; when the controllable converter is in the controllable In the normal operation condition of the controllable commutation mode, the first fully controlled device and the second fully controlled device are controlled to be synchronously opened or closed periodically, and the third fully controlled device and the bypass branch are controlled to be in a locked state; when the controllable converter is in the AC fault condition of the controllable commutation mode, the first fully controlled device and the second fully controlled device are controlled to be closed, and the bypass branch is locked; when the voltage of the capacitor in the controllable converter is greater than the preset voltage, the energy consumption branch in the controllable converter is controlled to be turned on to prevent the controllable converter from having overvoltage and / or commutation failure. It can be applied to UHV scenarios, and when in the AC fault condition of the controllable commutation mode, it can be controlled to be shut down so that the line does not have overvoltage and commutation failure problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A circuit of H-bridge topology structure provided by the present invention Figure 1 ; Figure 2 A circuit of H-bridge topology structure provided by the present invention Figure 2 ; Figure 3 An energy consumption branch structure diagram of an H-bridge topology structure provided by the present invention; Figure 4 A bypass branch structure diagram of an H-bridge topology structure provided by the present invention; Figure 5 A structural diagram of a main branch full-control valve provided in Example 2 of the present application; Figure 6A structural diagram of a main branch full-control valve provided in Example 3 of the present application; Figure 7 A structural diagram of a main branch full-control valve provided in Example 4 of the present application; Figure 8 A structural diagram of a controllable converter provided by the present invention; Fig. 9 A flow chart of a control method for a controllable converter provided by the present invention; Fig.10 An operating waveform diagram of a controllable commutation mode of a controllable converter method provided by the present invention under a normal operating condition; Fig.11 An operating waveform diagram of a controllable commutation mode of a controllable converter method provided by the present invention under an AC fault condition operating mode; Fig.12 An operating waveform diagram of a controllable converter method provided by the present invention in a conventional commutation mode; Fig.13 A schematic diagram of the operation of an electronic device provided in the present invention application. DETAILED DESCRIPTION

[0024] The specific implementation methods of the present invention are further described in detail below with reference to the accompanying drawings.

[0025] Embodiment 1: like Figure 1 , Figure 2 As shown: The present invention proposes an H-bridge topology structure, including: an H-bridge branch, an energy consumption branch and a bypass branch; the H-bridge branch includes: a first fully-controlled device T1, a second fully-controlled device T2, a first unidirectional conductive element D1, a second unidirectional conductive element D2 and a capacitor Ch; After the positive electrode of the first fully-controlled device and the first unidirectional conducting element are connected in forward series, the second fully-controlled device and the second unidirectional conducting element are connected in reverse series in sequence; the two ends of the capacitor and the energy-consuming branch after being connected in parallel are respectively connected to the connection point between the first unidirectional conducting element and the second fully-controlled device, and the connection point between the second unidirectional conducting element and the first fully-controlled device.

[0026] The above-mentioned H-bridge topology structure is divided into three parts according to functional division: H-bridge branch, bypass branch and energy-consuming branch: (1) The H-bridge branch is composed of fully-controlled devices (such as the first fully-controlled device and the second fully-controlled device), unidirectional conductive elements (such as the first unidirectional conductive element and the second unidirectional conductive element) and capacitors, forming an H-bridge structure in the form of two branches connected in parallel, which effectively reduces the current carrying capacity of the fully-controlled device; (2) The energy-consuming branch is composed of fully-controlled devices (such as the third fully-controlled device) and resistors in series, which is effective in AC fault current conditions. By real-time monitoring of the capacitor voltage, when the capacitor voltage exceeds the preset voltage Ua, the third full-control device is controlled to be turned on; when the capacitor voltage is lower than the minimum preset voltage Ub, the third full-control device is controlled to be turned off to charge the capacitor, thereby effectively controlling the voltage across the capacitor and ensuring that there is no overvoltage risk in the components in the H-bridge topology. The H-bridge topology of the present invention does not need to be connected to a lightning arrester for voltage limiting; (3) The bypass branch is connected in parallel at both ends of the H-bridge, which can realize controllable commutation mode operation, greatly improving the long-term operation reliability of the H-bridge topology.

[0027] The fully controlled device can be composed of one or more devices such as IGBT, IGCT (Integrated Gate-Commutated Thyristor), IEGT (Injection Enhanced Gate Transistor, IGBT series power electronic devices with a withstand voltage of more than 4KV), GTO (gate turn-off thyristor) or MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The H-bridge topology uses mature IGBT devices and diodes to form H-bridge branches, forming a natural parallel structure, which can meet the overload requirements of UHV DC projects.

[0028] The above-mentioned unidirectional conducting element is a diode or a thyristor. For example, the first unidirectional conducting element is a diode or a thyristor, and the second unidirectional conducting element is a diode or a thyristor. Figure 1 In the H-bridge topology structure, the first unidirectional conductive element D1 and the second unidirectional conductive element D2 are diodes; Figure 2 In the H-bridge topology structure, the first unidirectional conducting element D1 and the second unidirectional conducting element D2 are thyristors.

[0029] like Figure 3 As shown, the energy consumption branch is any one of the following three structures; like Figure 3As shown in (a), the first structure of the energy consumption branch includes: a resistor Rc and a third fully-controlled device T3, wherein the positive electrode of the third fully-controlled device is connected in series with one end of the resistor; and then Figure 2 In the connection mode shown, the cathode of the third fully-controlled device is connected to the connection point between the second unidirectional conducting element and the first fully-controlled device, and the other end of the resistor is connected to the connection point between the first unidirectional conducting element and the second fully-controlled device.

[0030] like Figure 3 (b) shows the second structure of the energy consumption branch, wherein the energy consumption branch comprises: a resistor, a third fully-controlled device and a diode, wherein the anode of the third fully-controlled device is connected to the anode of the diode, and the resistor is connected in parallel with the diode; and then Figure 2 In the connection mode shown, the cathode of the third fully-controlled device is connected to the connection point between the second unidirectional conductive element and the first fully-controlled device, and the cathode of the diode is connected to the connection point between the first unidirectional conductive element and the second fully-controlled device.

[0031] like Figure 3 As shown in (c), the third structure of the energy consumption branch includes: a resistor, a third fully-controlled device and a fuse, wherein the positive electrode of the third fully-controlled device is connected in series with one end of the resistor, and the other end of the resistor is connected in series with one end of the fuse, and then Figure 2 In the connection mode shown, the negative electrode of the third fully-controlled device is connected to the connection point between the second unidirectional conductive element and the first fully-controlled device, and the other end of the fuse is connected to the connection point between the first unidirectional conductive element and the second fully-controlled device.

[0032] In order to effectively suppress the influence of the stray inductance generated in the energy consumption branch on the turn-off overshoot stress of the third fully controlled device, a diode can be connected in parallel at both ends of the resistor in the energy consumption branch, such as Figure 3 As shown in (a), it can ensure that the energy-consuming branch can be opened reliably and the fuse can also be connected in series with the resistor.

[0033] like Figure 4 As shown, in order to effectively suppress the current change rate (di / dt) level of the H-bridge topology structure when the bypass branch is opened, the bypass branch can be adopted as follows Figure 4 (a) shows the thyristor series saturated reactor form, such as Figure 4 (b) The thyristor series inductor form, such as Figure 4 (c) Any of the bypass switch types shown.

[0034] In summary, the H-bridge topology is composed of power electronic devices with current shutoff and forward and reverse voltage blocking capabilities, and also has a bypass branch, which is composed of thyristors or their auxiliary devices. The H-bridge topology has the ability to withstand forward and reverse voltages and forms a natural parallel structure, which effectively reduces the selection requirements of the first fully controlled device, the second fully controlled device, and the third fully controlled device, and can meet the needs of large-scale new energy transmission scenarios through ultra-high voltage direct current.

[0035] Embodiment 2: An embodiment of the present invention also provides a main branch full-control valve, including multiple H-bridge topology structures shown in the above-mentioned embodiment 1. The multiple H-bridge topology structures can be connected in any of the three structural forms: internal series form, series and parallel combination form, and overall series form to form a main branch full-control valve.

[0036] For the internal series structure, such as Figure 5 As shown, the first fully-controlled device, the second fully-controlled device, the first unidirectional conductive element, the second unidirectional conductive element, the capacitor, the energy-consuming branch and the bypass branch in the H-bridge branches in the H-bridge topology are connected in series respectively, forming a main branch fully-controlled valve in series inside the H-bridge topology structure, which saves space and can achieve a compact design.

[0037] For the structural forms of series and parallel combination, such as Figure 6 As shown, a main branch full-control valve comprises: a plurality of H-bridge topology structures and a plurality of thyristors; after the connection point of the second full-control device and the second unidirectional conduction element in one H-bridge topology structure and the connection point of the first full-control device and the first unidirectional conduction element in another H-bridge topology structure are sequentially connected in series, a plurality of thyristors in series are connected in parallel as a whole. A main branch full-control valve in the form of a series and parallel combination is formed, and a single H-bridge topology structure in this structure can be controlled by a bypass branch when a fault occurs.

[0038] For the overall series structure, such as Figure 7 As shown, a main branch full-control valve comprises: a plurality of H-bridge topology structures; a connection point between a second full-control device and a second unidirectional conductive element in one H-bridge topology structure and a connection point between a first full-control device and a first unidirectional conductive element in another H-bridge topology structure are sequentially connected in series. A main branch full-control valve in the form of an overall series connection of H-bridge topology structures is formed, and a single H-bridge topology structure in this structure is controlled by bypassing, respectively, without adding bypass switch devices.

[0039] Embodiment 3: like Figure 8As shown, the present invention proposes a controllable converter, including: a bridge arm connected in parallel in a three-phase power system, each phase bridge arm including: a plurality of valves connected in series (for example, Figure 8 V1, V2, V3, V4, V5, V6); the valve includes: a main branch, a main lightning arrester Arr1, and an auxiliary branch; The main branch, the main arrester and the auxiliary branch are connected in parallel; The main branch includes: the main branch full-control valve as described in the above embodiment 2; The auxiliary branch includes: a plurality of high-pressure full-control valves V13 and V14 connected in series, the high-pressure full-control valve V13 has a variable resistor Arr3 inside, the high-pressure full-control valve V14 has a variable resistor Arr4 inside, and an auxiliary saturated reactor Thy4.

[0040] The controllable converter of the present invention is a new type of high-voltage direct current commutation equipment based on a converter (LCC). It adopts a mixed connection of full / half-controlled devices to form a topological structure of parallel connection of the main and auxiliary branches. This topology maintains the thyristor as the main current-passing element, giving full play to its advantages of large transmission capacity, low loss and high economy. At the same time, a small number of fully controlled devices and main thyristor valves can be connected in series in the main branch. The main thyristor valve V11 includes a thyristor Thy1 and a main saturated reactor to realize current transfer and provide a negative turn-off voltage for the thyristor in the main branch. When an AC fault occurs, the current is transferred from the main branch to the auxiliary branch. After the main branch is turned off, the high-voltage fully controlled valve V13 or high-voltage fully controlled valve V14 in the auxiliary branch is actively turned off, and the current is transferred to the arrester. The arrester establishes an action voltage, enhances the commutation voltage, and realizes forced commutation. The main arrester is used to limit the impact overvoltage of the entire single valve. It fundamentally solves the commutation failure problem of conventional power grid commutation converters.

[0041] Furthermore, the main branch also includes: a main saturated reactor and a thyristor; The main saturated reactor, the thyristor and the main branch full-control valve are connected in series in a forward direction in sequence.

[0042] The main branch full-control valve is connected to the main saturated reactor to limit the current change rate (di / dt) when the main branch full-control valve is opened, thereby protecting the thyristor; Furthermore, the converter further comprises: a central controller; the central controller is connected to the first fully-controlled device, the second fully-controlled device, the third fully-controlled device, the capacitor, and the bypass branch in the main branch fully-controlled valve via an optical fiber; When an AC fault occurs, the central controller controls the triggering or shutting down of the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device to implement forced commutation for detecting the voltage of the capacitor.

[0043] The above-mentioned central controller is intended to realize control over the first full-control device, the second full-control device, the third full-control device, the capacitor, and the bypass branch in the main branch full-control valve, realize control over the converter in various working conditions, and especially realize forced commutation of the converter when an AC fault occurs.

[0044] Embodiment 4: like Fig. 9 As shown, the present invention also proposes a control method for a controllable converter, comprising: Step 1: using a central controller in the controllable converter to determine an operation mode of the controllable converter based on the actual operating condition of the controllable converter, wherein the operation mode includes a conventional commutation mode and / or a controllable commutation mode; Step 1.1: When the controllable converter is in the normal commutation mode, the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device in the main branch fully-controlled valve in the controllable converter are controlled to be in a locked state, and the bypass branch in the main branch fully-controlled valve is controlled to be periodically opened or closed; Step 1.2.1: When the controllable converter is in the normal operating condition of the controllable commutation mode, the first fully-controlled device and the second fully-controlled device are controlled to be synchronously periodically turned on or off, and the third fully-controlled device and the bypass branch are controlled to be in a locked state; Step 1.2.2: When the controllable converter is in the AC fault condition of the controllable commutation mode, the first fully-controlled device and the second fully-controlled device are controlled to be turned off and the bypass branch is locked; when the voltage of the capacitor in the controllable converter is greater than the preset voltage, the energy-consuming branch in the controllable converter is controlled to be turned on to prevent the controllable converter from overvoltage and / or commutation failure.

[0045] Further, in step 1.2.1, when the controllable converter is in the normal operating condition of the controllable commutation mode, controlling the first fully-controlled device and the second fully-controlled device to be synchronously periodically turned on or off, and controlling the third fully-controlled device and the bypass branch to be in a locked state, includes: When the controllable converter is in the normal operating condition of the controllable commutation mode, the voltage of the capacitor in the controllable converter is periodically selected and the voltage is transmitted to the valve in the controllable converter; so that the valve adaptively adjusts the on or off period of the first fully-controlled device and the second fully-controlled device within a preset voltage range according to the voltage.

[0046] The control method of the controllable converter of the present invention mainly includes: a controllable commutation mode and a conventional commutation mode; (1) The controllable commutation modes include: normal operation mode and AC fault operation mode. The two operation modes are as follows: In the two operating modes of the controllable commutation mode, the valve sends a switch command to the H-bridge topology structure to execute the switch command of the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device.

[0047] like Fig.10 As shown, t 0、 t 1、 Time t2 is the triggering time of the main branch full control valve, t 0ff、 t 0ff1、 t 0ff2 The moment is the closing moment of the main branch full-control valve, t is the time, in the normal operation mode, the central controller synchronously and periodically triggers the first full-control device T1 and the second full-control device T2, the control period is dT=20ms, according to the control signal of the valve, after the dT1 time period, the first full-control device T1 and the second full-control device T2 are synchronously closed, the dT1 time period is selected to be related to the voltage of the root capacitor Ch, the specific relationship is: the capacitor voltage is collected by the central controller and uploaded to the valve, and the valve adaptively adjusts the dT1 value according to the preset voltage range (U1, U2) When the capacitor voltage is higher than U2, dT1 increases by Δt1, that is, dT1+Δt1, Δt1 is the delay adjustment accuracy, which is related to the capacitor voltage change rate. When the capacitor voltage is lower than U1, dT1 decreases by Δt2, that is, dT1-Δt2, Δt1 is the advance adjustment accuracy, which is related to the capacitor voltage change rate, so that the capacitor voltage falls within the preset voltage range (U1, U2), and then operates stably according to the control method; during operation, the third fully-controlled device T3 and the bypass branch P1 are in a locked state, and the control will only be started when a fault occurs.

[0048] As mentioned above, the purpose of setting the voltage range is: 1) to ensure that the maximum voltage of the main branch full-control valve does not exceed the voltage U2 during long-term operation, so as to prevent excessive voltage from affecting the long-term operation reliability of the device; 2) the long-term operation voltage is higher than U1 to ensure that there is enough voltage for the main thyristor, so that the reverse shutdown voltage is conducive to the recovery of the thyristor.

[0049] like Fig.11 As shown, t 0、 t 1、 Time t2 is the triggering time of the main branch full control valve, t 0ff、 t 0ff1、 t 0ff2The time is the time when the main branch full-control valve is turned off, and t is the time. In the AC fault condition operation mode, the first full-control device T1 and the second full-control device T2 will turn off the large current. At this time, the third full-control device T3 of the energy-consuming branch is directly controlled by the central controller. When the first full-control device T1 and the second full-control device T2 are turned off, the capacitor Ch is charged. Ua is the turn-on voltage threshold of the third full-control device T3; Ub is the turn-off voltage threshold of the third full-control device T3. When the central controller monitors the capacitor voltage UCh≥Ua, Ua>U2, the third full-control device T3 is turned on. When UCh≤Ub, the third full-control device T3 is turned off, and the bypass branch is in a locked state. Only when the H-bridge structure fails, the bypass branch P1 is started to perform the overvoltage protection function to ensure that the components in the H-bridge structure will not be damaged.

[0050] (2) Conventional commutation mode like Fig.12 As shown, t is the time. When the conventional commutation mode is in operation, the first fully-controlled device T1, the second fully-controlled device T2, and the third fully-controlled device T3 are all in a locked state. The thyristor in the bypass branch P1 is periodically triggered according to the control command issued by the valve, and the conduction interval is dT2=6.67ms.

[0051] Embodiment 5: like Fig.13 As shown, the present invention also provides an electronic device, which may be a computer device, a single-chip device, an intelligent mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor, and the transceiver component are connected via a bus; the memory may be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory may also be used to store data, which may be called and / or modified when the instructions are executed.

[0052] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of a control method of a controllable converter in the above-mentioned embodiment.

[0053] Embodiment 6: Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory), which is a memory device in an electronic device for storing programs and data. It can be understood that the storage medium here can include both built-in storage media in electronic devices and extended storage media supported by electronic devices. The storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor loads and executes one or more instructions stored in the storage medium, which can implement the steps of a control method of a controllable converter in the above embodiment.

[0054] Those skilled in the art will appreciate that the embodiments of the present invention application may be provided as methods, systems, or computer program products. Therefore, the present invention application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0055] The present invention application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present invention application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0056] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0057] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention application rather than to limit its protection scope. Although the present invention application is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present invention application, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the application, but these changes, modifications or equivalent substitutions are all within the protection scope of the claims to be approved.

Claims

1. An H-bridge topology structure, characterized in that: include: H-bridge branch, energy consumption branch and bypass branch; The H-bridge branch includes: a first fully-controlled device, a second fully-controlled device, a first unidirectional conductive element, a second unidirectional conductive element and a capacitor; After the positive electrode of the first fully-controlled device and the first unidirectional conducting element are connected in forward series, the second fully-controlled device and the second unidirectional conducting element are connected in reverse series in sequence; the two ends of the capacitor and the energy-consuming branch after being connected in parallel are respectively connected to the connection point between the first unidirectional conducting element and the second fully-controlled device, and the connection point between the second unidirectional conducting element and the first fully-controlled device.

2. The H-bridge topology structure according to claim 1, characterized in that: The energy consumption branch includes: A resistor and a third fully-controlled device, wherein the positive electrode of the third fully-controlled device is connected in series with one end of the resistor; the negative electrode of the third fully-controlled device is connected to the connection point between the second unidirectional conductive element and the first fully-controlled device, and the other end of the resistor is connected to the connection point between the first unidirectional conductive element and the second fully-controlled device.

3. The H-bridge topology structure according to claim 1, characterized in that: The energy consumption branch includes: a resistor, a third fully-controlled device and a diode, wherein the positive electrode of the third fully-controlled device is connected to the positive electrode of the diode, and the resistor is connected in parallel with the diode; the negative electrode of the third fully-controlled device is connected to the connection point between the second unidirectional conductive element and the first fully-controlled device, and the negative electrode of the diode is connected to the connection point between the first unidirectional conductive element and the second fully-controlled device.

4. The H-bridge topology structure according to claim 1, characterized in that: The energy consumption branch includes: a resistor, a third fully-controlled device and a fuse, wherein the positive electrode of the third fully-controlled device is connected in series to one end of the resistor, the other end of the resistor is connected in series to one end of the fuse, the negative electrode of the third fully-controlled device is connected to the connection point between the second unidirectional conductive element and the first fully-controlled device, and the other end of the fuse is connected to the connection point between the first unidirectional conductive element and the second fully-controlled device.

5. The H-bridge topology structure according to claim 1, characterized in that: The first unidirectional conducting element is a diode or a thyristor, and the second unidirectional conducting element is a diode or a thyristor.

6. A main branch full control valve, characterized in that: include: A plurality of H-bridge topologies as described in any one of claims 1 to 5; a first fully-controlled device, a second fully-controlled device, a first unidirectional conductive element, a second unidirectional conductive element, a capacitor, an energy-consuming branch and a bypass branch in the H-bridge branches in the plurality of said H-bridge topologies are connected in series respectively.

7. A main branch full control valve, characterized in that: include: A plurality of H-bridge topologies as described in any one of claims 1 to 5 and a plurality of thyristors; after the connection point of the second fully-controlled device and the second unidirectional conducting element in one of the H-bridge topologies is connected in series with the connection point of the first fully-controlled device and the first unidirectional conducting element in another of the H-bridge topologies in sequence, a plurality of thyristors in series are connected in parallel as a whole.

8. A main branch full control valve, characterized in that: include: A plurality of H-bridge topologies as described in any one of claims 1 to 5; the connection point between the second fully-controlled device and the second unidirectional conducting element in one of the H-bridge topologies is connected in series with the connection point between the first fully-controlled device and the first unidirectional conducting element in another of the H-bridge topologies.

9. A controllable converter, characterized in that: include: A bridge arm connected in parallel in the three-phase electricity, each phase bridge arm includes: a plurality of valves connected in series; the valves include: a main branch, a main lightning arrester, and an auxiliary branch; The main branch, the main lightning arrester and the auxiliary branch are connected in parallel; The main branch comprises: a main branch full-control valve as claimed in any one of claims 6 to 8; The auxiliary branch includes: a plurality of high-pressure full-control valves connected in series.

10. The inverter according to claim 9, characterized in that: The main branch also includes: a main saturated reactor and a thyristor; The main saturated reactor, the thyristor and the main branch full-control valve are connected in series in a forward direction in sequence.

11. The inverter according to claim 9, characterized in that: Also includes: Central controller; the central controller is connected to the first full-control device, the second full-control device, the third full-control device, the capacitor, and the bypass branch in the main branch full-control valve through optical fibers; When an AC fault occurs, the central controller controls the triggering or shutting down of the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device to implement forced commutation for detecting the voltage of the capacitor.

12. A control method for a controllable converter, characterized in that: include: Using a central controller in the controllable converter, based on the actual working condition of the controllable converter, determining an operating mode of the controllable converter, wherein the operating mode includes a conventional commutation mode and / or a controllable commutation mode; When the controllable converter is in the conventional commutation mode, the first fully-controlled device, the second fully-controlled device, and the third fully-controlled device in the main branch fully-controlled valve in the controllable converter are controlled to be in a locked state, and the bypass branch in the main branch fully-controlled valve is controlled to be periodically opened or closed; When the controllable converter is in the normal operating condition of the controllable commutation mode, the first fully-controlled device and the second fully-controlled device are controlled to be synchronously periodically turned on or off, and the third fully-controlled device and the bypass branch are controlled to be in a locked state; When the controllable converter is in the AC fault condition of the controllable commutation mode, the first fully-controlled device and the second fully-controlled device are controlled to be turned off and the bypass branch is locked; when the voltage of the capacitor in the controllable converter is greater than the preset voltage, the energy consumption branch in the controllable converter is controlled to be turned on to prevent the controllable converter from overvoltage and / or commutation failure; Wherein, the controllable converter is the controllable converter described in any one of claims 9-11.

13. The method according to claim 12, characterized in that When the controllable converter is in the normal operating condition of the controllable commutation mode, controlling the first fully-controlled device and the second fully-controlled device to be synchronously periodically turned on or off, and controlling the third fully-controlled device and the bypass branch to be in a locked state, includes: When the controllable converter is in the normal operating condition of the controllable commutation mode, the voltage of the capacitor in the controllable converter is periodically selected and the voltage is transmitted to the valve in the controllable converter; so that the valve adaptively adjusts the on or off period of the first fully-controlled device and the second fully-controlled device within a preset voltage range according to the voltage.

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