WO2024051839A1 - 一种联络型供电变压器及其调控方法 - Google Patents

一种联络型供电变压器及其调控方法 Download PDF

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Publication number
WO2024051839A1
WO2024051839A1 PCT/CN2023/117856 CN2023117856W WO2024051839A1 WO 2024051839 A1 WO2024051839 A1 WO 2024051839A1 CN 2023117856 W CN2023117856 W CN 2023117856W WO 2024051839 A1 WO2024051839 A1 WO 2024051839A1
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WIPO (PCT)
Prior art keywords
transformer
line
switch
power supply
voltage
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PCT/CN2023/117856
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English (en)
French (fr)
Inventor
慕小斌
陈国富
王翔
赵国亮
李卫国
戴凤娇
袁佩娥
原亚雷
谷伟明
王志凯
李宏浩
丁长新
张璐
Original Assignee
国网智能电网研究院有限公司
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Publication of WO2024051839A1 publication Critical patent/WO2024051839A1/zh

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
    • H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/29—Terminals; Tapping arrangements for signal inductances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/40—Structural association with built-in electric component, e.g. fuse
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00—Variable transformers or inductances not covered by group H01F21/00
    • H01F29/02—Variable transformers or inductances not covered by group H01F21/00 with tappings on coil or winding; with provision for rearrangement or interconnection of windings
    • H01F29/025—Constructional details of transformers or reactors with tapping on coil or windings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/01—Arrangements for reducing harmonics or ripples
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
    • H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
    • H02M5/10—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using transformers
    • H02M5/12—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using transformers for conversion of voltage or current amplitude only
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
    • H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
    • H02M5/10—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using transformers
    • H02M5/18—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using transformers for conversion of waveform
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
    • H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
    • H02M5/22—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M5/275—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M5/293—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M5/2932—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage, current or power
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P13/00—Arrangements for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output
    • H02P13/06—Arrangements for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output by tap-changing; by rearranging interconnections of windings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F2038/006—Adaptations of transformers or inductances for specific applications or functions matrix transformer consisting of several interconnected individual transformers working as a whole

Definitions

  • This application relates to the field of power systems, and specifically to a contact power supply transformer and its control method.
  • the power grid As the basic carrying network for various energy sources, the power grid's ability to operate safely, stably, and reliably directly affects the acceptance of new energy sources and the quality of power supply for users.
  • my country's distribution network mainly operates in the mode of "closed-loop design, open-loop operation". Facing the large-scale access to distributed new energy power generation, its power generation output is highly random, intermittent and volatile, resulting in
  • the open-loop distribution network has problems such as large voltage fluctuations, reverse power flow overload, and difficulty in operating the ring network.
  • the distribution network is also facing outstanding problems such as difficulty in increasing capacity and low utilization of distribution equipment and lines. These problems include Due to the advancement of the goal of "carbon peaking and carbon neutrality".
  • the core technology for realizing closed-loop operation of the distribution network is flexible loop closing technology, which uses specific devices to physically connect the lines on both sides of the loop closing point, and uses control means to control the power flowing through the loop closing point, combining each line
  • the remaining capacity is used to optimize the mutual transmission capacity of the lines, thereby improving the carrying capacity of the power grid lines, consuming new energy as efficiently as possible and improving the resources of the power grid. Source utilization.
  • the flexible loop closing equipment formed by these technologies not only has a series of problems such as high cost, large losses, low reliability, and difficult maintenance, but also requires additional land to install the equipment, because the demand for loop closing in the distribution network is multi-faceted. Therefore, the existing technology has problems such as low practicality, complex operation, and difficulty in promotion.
  • this application provides a contact type power supply transformer and its control method to solve the problems of high cost, large loss, low reliability, difficult maintenance, large extra space, etc.
  • the degree of practicality is not high, the operation is complex, and the promotion is difficult. question.
  • connection type power supply transformer which is configured to transmit the electric energy of the first line and the second line of the power grid line to the power supply end, and connect the first line and the second line.
  • the specified power of electric energy is transmitted to each other.
  • the contact power supply transformer includes a multi-phase parallel transformer, a multi-phase series transformer and a plurality of safety protection auxiliary regulating devices; the primary ends of the multi-phase parallel transformers are connected to the first line, the ends of the primary sides are connected to form the first neutral point; the secondary side of the parallel transformer has at least one power supply winding and a plurality of asymmetric windings, the power supply winding is connected to the power supply end, and the plurality of asymmetrical windings are The windings are interconnected through their corresponding switching bridge arm modules with the bridge arm modules corresponding to the asymmetric windings of the secondary side of the adjacent phase parallel transformer to obtain the first electrical quantity. The first electrical quantity passes through the secondary side of the corresponding series transformer.
  • the plurality of safety protection auxiliary regulating devices are connected in series between the first line and the second line and are configured to control the third line.
  • a line and the second line perform power quality isolation and fault isolation, dynamic adjustment of the connection power of the first line and the second line, and line fault protection of the multi-phase series transformer.
  • the contact power supply transformer provided by the embodiment of the present application is provided with a multi-phase parallel transformer, a multi-phase series transformer and multiple safety protection auxiliary regulating devices.
  • the switch bridge arm module provided in the parallel transformer performs vector transformation and synthesis of the input voltage.
  • the first electrical quantity is obtained, and then combined with the safety protection auxiliary adjustment device to actively protect, isolate and adjust the fault, power quality, power and impedance of the contact circuit.
  • the power supply transformer connects the lines, it will not increase the risk of the grid's short-circuit current exceeding the standard due to the line connection.
  • the power supply transformer is used to realize the connection of the lines, which improves the reuse function of the device. , eliminating the need for separate communication devices for line communication, greatly improving the economy and practicality, and making it easy to promote and use.
  • At least one of the primary end and the primary end of the parallel transformer has multiple taps, and the multiple taps are configured to stably regulate the voltage of the secondary power supply winding of the parallel transformer.
  • At least one of the primary end and the primary end of the parallel transformer is provided with multiple taps, and different taps can be selected through uninterruptible power supply to achieve stable regulation of the voltage of the secondary power supply winding of the parallel transformer.
  • the asymmetric winding includes multiple taps
  • the parallel transformer includes multiple voltage regulating devices
  • the multiple voltage regulating devices include the same number of switches as the asymmetric windings of the parallel transformer.
  • Bridge arm module correspondingly, the plurality of taps are connected to the input end of the switch bridge arm module; the voltage regulating device controls the corresponding switch state of the bridge arm of the switch bridge arm module.
  • the multiple taps are gated in a preset manner to interconnect the multiple asymmetric windings with the asymmetric windings of parallel transformers of adjacent phases in a continuous, intermittent or normally open/normally closed electrical working mode to obtain the third An electrical quantity, the preset mode includes normally open, normally closed, and intermittently conductive winding according to a preset frequency.
  • multiple voltage regulating devices are provided in the parallel transformer, and the number of switching bridge arm modules is set in the multiple voltage regulating devices to be the same as the number of asymmetric windings of the parallel transformer, thereby achieving the use of a smaller number of windings and taps. and the number of switching devices can achieve more voltage vector regulation output, greatly improving the range and granularity of adjusting the voltage vector.
  • the primary side of the multi-phase series transformer is connected in series between the first line and the second line respectively; the secondary input end of the series transformer is connected to the parallel transformer of two adjacent phases.
  • the asymmetric winding of the current phase parallel transformer and the asymmetric winding of the current phase parallel transformer are connected in turn through the switch arm module, and an output end of the switch arm winding corresponding to the asymmetric winding of the current phase parallel transformer is connected to the second neutral point.
  • the secondary side of the multi-phase series transformer further includes a redundant reactor, which is connected to both ends of the secondary winding of the series transformer through a switch and is configured to suppress the When the series transformer is operating normally, it can withstand a current that is longer than the first threshold and has a magnitude greater than the fifth threshold.
  • a third switch is connected in parallel to both ends of the primary side of each phase series transformer.
  • the safety protection auxiliary adjustment device includes a first controllable switch, a second controllable switch, a third controllable switch, a fourth controllable switch, and a third switch. switch, a first capacitor, a second capacitor, a first inductor, a first resistor, a first switch and an overvoltage absorber, wherein when the power supply transformer is operating normally, the third switch is turned off, and the second switch is open.
  • the control switch and the fourth controllable switch are closed, the first controllable switch, the third controllable switch and the second switch are open, and the safety protection auxiliary adjustment device presents a harmonic high resistance characteristics, blocking harmonics higher than the second threshold from passing through the transformer and lines and thus having an adverse impact on the power supply system; when a short circuit fault occurs between the first line and the second line connected to the power supply transformer, the first controllable The switch, the third controllable switch and the fourth controllable switch are closed, the second controllable switch and the second switch are open, and the safety protection auxiliary adjustment device presents a high resistance state with a set bandwidth.
  • auxiliary regulating device directly connects the two lines and presents an adjustable reactance state of inductive reactance, capacitive reactance, impedance or a combination of the three, and is configured to regulate the contact power; when the safety protection auxiliary regulating device stops working Or when only the series transformer and the parallel transformer are required to work, the third switch is turned off, the second switch is closed, and the first controllable switch, the second controllable switch, the third controllable switch, and
  • a first controllable switch, a second controllable switch, a third controllable switch, a fourth controllable switch, a first capacitor, a second capacitor, a first inductor, and a third controllable switch are provided in the safety protection auxiliary adjustment device.
  • a resistor, a second switch and an overvoltage absorber realize power quality isolation by adjusting the switching status of each switch in the safety protection auxiliary adjustment device.
  • the safety protection auxiliary adjustment device can directly connect the two lines independently of the series and parallel transformers, and maintain a certain It can adjust the power of the contact point to a certain extent, saving unnecessary working links of the loop closing device in certain working conditions.
  • the safety protection auxiliary regulating device is integrated into the contact power supply transformer as a multi-functional device, which improves the working efficiency of the entire power supply transformer and reduces system losses.
  • the tie-type power supply transformer further includes: a fine compensation device and a first bypass switch and a second bypass switch.
  • the input end of the fine compensation device passes through the first bypass switch and the second bypass switch.
  • the second bypass switch is connected to the secondary output end of the series transformer, and the fine compensation device is composed of a four-phenomenon converter with AC-DC conversion or AC-AC conversion function, and is configured to output a continuously changing third Two electrical quantities.
  • the first bypass switch and the second bypass switch are in the disconnected state, the second output voltage is superimposed on the first electrical quantity and coupled through the secondary side of the corresponding series transformer. the primary side of the series transformer.
  • a continuously changing second electrical quantity can be obtained by using a fine compensation device and a DC source composed of a four-phenomenon converter with an AC-DC conversion function, and the obtained first electrical quantity and the second electrical quantity can be synthesized. Coupled to the line via a series transformer.
  • the tie-type power supply transformer further includes: a grounding device configured to In order to ground the first neutral point, a grounding reactor and a grounding resistor are connected in series, and the reactance value of the grounding reactor and the resistance value of the grounding resistor are adjustable.
  • the embodiment of the present application can ensure the reliable operation of the transformer and eliminate the need for additional grounding devices that must be added to the substation due to the need for cable line ground fault detection.
  • the present application provides a power supply transformer control method, which should be configured as the power supply transformer described in the embodiment of the present application.
  • the method includes: the parallel transformer operates continuously, intermittent, or normally open/normally closed according to the three-phase input voltage.
  • the electrical working mode adjusts the switching status of multiple switch bridge arm modules to output a first electrical quantity; adjusts a fine compensation device, and the fine compensation device outputs a continuously changing second electrical quantity; and combines the first electrical quantity and the The voltage vector generated by the superposition of the second electrical quantity acts on the secondary winding of the multi-phase series transformer.
  • the primary winding of the series transformer superimposes the voltage vector coupled from the secondary winding onto the three-phase input voltage to form the first line and the second line.
  • the three-phase input voltage is vector transformed and synthesized to obtain a first electrical quantity by adjusting the switching bridge arm modules of multiple voltage regulating devices in a multi-phase parallel transformer, and the fine compensation device adjusts and outputs a continuously changing second electrical quantity.
  • the obtained first electrical quantity and the second electrical quantity are synthesized and superimposed on the input voltage through series transformer coupling, achieving continuous stepless and precise adjustment of the device's output electrical quantity and constructing special adjustment functions such as voltage, impedance, and harmonics. .
  • adjusting the fine compensation device which outputs a continuously changing second electrical quantity, includes: determining to adjust the fine compensation according to the desired voltage vector and the first electrical quantity output by the parallel transformer.
  • the command variable of the device perform vector frequency division control calculation on the command variable and the output voltage of the fine compensation device, and then combine it with the DC voltage control amount of the fine compensation device to obtain a control signal; according to the control signal after modulation conversion
  • the fine compensation device is adjusted, and the fine compensation device outputs a continuously changing second electrical quantity.
  • the embodiment of the present application uses the desired voltage vector, the first electrical quantity output by the three-phase parallel transformer, the output voltage of the fine compensation device, and the DC voltage output by the fine compensation device based on vector analysis.
  • the frequency control method determines the control signal, and adjusts the fine compensation device to output a continuously changing second electrical quantity according to the control signal.
  • This control method can quickly respond to instructions and perform frequency domain analysis control on the instructions at each frequency, and realize point-to-point control of the instructions. Accurate tracking can not only achieve the output of desired variables with high precision, but also facilitate resonance analysis and early warning, dynamically change the control gain of each frequency point, and avoid high-gain control at the resonance risk point of the system.
  • the command variable and the output voltage of the fine compensation device are subjected to vector frequency division control calculation, and then combined with the DC voltage control amount of the fine compensation device to obtain a control signal, including: converting the command The variables are subjected to Fourier transformation to obtain the command quantity at each frequency; the output voltage of the fine compensation device is subjected to Fourier transformation to obtain the actual output quantity at each frequency; the command quantity and the actual output quantity are obtained After making the difference, the first signal is obtained through error control and inverse Fourier transform; the DC voltage and DC command output by the fine compensation device are obtained through error control and AC conversion to obtain the second signal; according to the first signal, the second signal The control signal is obtained by adding the feedforward amount obtained by calculating the command variable in advance.
  • control signal is obtained by Fourier transforming the command variable and the output voltage of the fine compensation device and subjecting it to error control, and then adding the feedforward amount obtained by calculating the command variable in advance through the inverse Fourier transform. , which improves the speed of frequency domain analysis and control of instructions at each frequency, and improves the tracking speed and precision of instructions and the accuracy of control signals.
  • the desired voltage vector includes: voltage smoothing variables, fundamental impedance variables, harmonic voltage adjustment variables, and harmonic impedance adjustment variables.
  • the embodiment of the present application expects that the voltage vector selection voltage smoothing variable, fundamental impedance variable, harmonic voltage adjustment variable and harmonic impedance adjustment variable can realize continuous smooth adjustment, fundamental impedance adjustment, harmonic voltage adjustment and harmonic adjustment of the fine compensation device. Impedance adjustment, etc.
  • Figure 1 is a structural diagram of a flexible loop closing technology route provided in the prior art
  • Figure 2 is a structural diagram of a flexible loop closing technology route provided by an embodiment of the present application.
  • Figure 3 is a topological structure diagram of a contact power supply transformer provided by an embodiment of the present application.
  • Figure 4 is a topological structure diagram of a multi-phase parallel transformer provided by an embodiment of the present application.
  • Figure 5 is a topological structure diagram of a voltage regulating device provided by an embodiment of the present application.
  • Figure 6 is a topological structure diagram of a safety protection auxiliary adjustment device provided by an embodiment of the present application.
  • Figure 7 is a flow chart of a power supply transformer control method provided by an embodiment of the present application.
  • Figure 8 is a flow chart of a power supply transformer control method provided by an embodiment of the present application.
  • Figure 9 is a flow chart of a power supply transformer control method provided by an embodiment of the present application.
  • Figure 10 is a flow chart of a power supply transformer control method provided by an embodiment of the present application.
  • the term "install”, “connect” and “connect” should be understood in a broad sense.
  • it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection.
  • the connection can also be indirect through an intermediary, or it can be an internal connection between two components. It can be a wireless connection or a wired connection.
  • install e.g., it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection.
  • the connection can also be indirect through an intermediary, or it can be an internal connection between two components. It can be a wireless connection or a wired connection.
  • the specific meanings of the above terms in this application can be understood on a case-by-case basis.
  • this application discloses a contact-type power supply transformer with a flexible loop-closing function.
  • This power supply transformer can not only realize the traditional power supply function but also connect the lines on both sides of the loop-closing point nearby. Perform flexible loop closure.
  • the connection relationship of the power supply transformer in the line is shown in Figure 2.
  • This contact type power supply transformer with flexible loop closing function can be directly obtained by transforming and upgrading the existing Taiwan area transformer. Therefore, the power supply transformer provided by the embodiment of the present application does not need to occupy additional space. It can realize flexible loop closing only through the power supply transformer itself, and can realize flexible adjustment of the power flowing through the loop closing point, and also has the ability to actively regulate the power grid.
  • connection type power supply transformer is configured to transmit the electric energy of the first line and the second line of the power grid line to the power supply end, and connect the first line and the second line of the power grid to the power supply end.
  • the second line carries out communication and mutual transmission of electric energy of specified power.
  • the communication power supply transformer includes a multi-phase parallel transformer, a multi-phase series transformer and multiple safety protection auxiliary regulating devices.
  • the first end of the primary side of the multi-phase parallel transformer is connected to the first line, and the ends of the primary side are connected to form the first neutral point;
  • the secondary side of the parallel transformer has at least one power supply winding and multiple asymmetric windings, and the power supply winding is connected to the first neutral point.
  • the power supply end is connected, and the first electrical quantity is obtained after multiple asymmetric windings are interconnected with the bridge arm modules corresponding to the secondary side asymmetric windings of adjacent phase parallel transformers through their corresponding switch bridge arm modules.
  • the first electrical quantity passes through
  • the secondary side of the corresponding series transformer is coupled to the primary side of the series transformer to access the second line;
  • a plurality of safety protection auxiliary regulating devices are connected in series between the first line and the second line and are configured to control the first line and the second line.
  • the second line performs power quality isolation and fault isolation, dynamic adjustment of the contact power of the first line and the second line, and line fault protection of the multi-phase series transformer.
  • the primary side of the multi-phase series transformer is connected in series between the first line and the second line respectively; the secondary input end of the series transformer is connected in sequence with the asymmetric windings of the parallel transformers of two adjacent phases and the asymmetric windings of the parallel transformer of this phase.
  • the switching arm module Through the connection of the switching arm module, one output end of the switching arm module corresponding to the asymmetric winding of the current parallel transformer is connected to the second neutral point.
  • the tie-type power supply transformer in the embodiment of the present application can realize the transmission of electric energy from the first line to the second line, can also realize the transmission of electric energy from the second line to the first line, and can also realize the transmission of electric energy between the first line and/or the third line.
  • the second line transmits electric energy to the power supply end.
  • the setting of asymmetric windings can achieve more adjustment steps and better adjustment accuracy with fewer taps.
  • the primary ends of the parallel transformers of each phase are connected to form the first neutral point O, and the power supply ports U, V, and W of the power supply winding can supply power to the load, realizing a single Phase power supply or three-phase power supply, plus port N can realize three-phase four-wire power supply.
  • Dynamic adjustment of contact power means to determine based on the transmission capacity of the first line and the transmission capacity of the second line: transfer the power of the first line to the second line to meet the required power, and transfer the power of the second line to the first line. The power that meets the requirements, or the first line and the second line supply power to the power supply terminal (U, V, W) at the same time.
  • FIG. 3 is the topology diagram of the communication power supply transformer, including the multi-phase parallel transformer.
  • Figure 4 is the connection power supply transformer of Figure 3.
  • Electric transformers include multi-phase parallel transformers.
  • the multi-phase parallel transformers are A, B and C phase parallel transformers respectively.
  • the multi-phase series transformers are A, B and C phase series transformers respectively.
  • a phase The input end of the safety protection auxiliary regulating device in the line is connected to the input end of the A-phase line and the input end of the A-phase primary side of the A-phase parallel transformer.
  • the output end of the safety protection auxiliary regulating device in the A-phase line is connected to the A-phase primary side of the three-phase series transformer.
  • the input end of the side, the output end of the A-phase primary side of the three-phase series transformer is connected to the output end of the A-phase line, the first end A 11 of the A-phase secondary winding of the series transformer and the voltage regulating device SM-b1 of the B-phase secondary side of the parallel transformer
  • the first output terminal b 1p is connected, the second output terminal b 1n of the voltage regulating device SM-b1 on the B-phase secondary side is connected to the first output terminal c2p of the voltage regulating device SM-c2 on the C-phase secondary side, and the C-phase
  • the second output terminal c 2n of the secondary voltage regulating device SM-c2 is connected to the first output terminal a 3p of the A-phase secondary voltage regulating device SM-a3.
  • the input end of the safety protection auxiliary adjustment device in the B-phase line is connected to the input end of the B-phase line and the input end of the B-phase primary side of the B-phase parallel transformer.
  • the safety protection auxiliary adjustment device in the B-phase line The output terminal is connected to the input terminal of the B-phase primary side of the three-phase series transformer, the output terminal of the B-phase primary side of the three-phase series transformer is connected to the output terminal of the B-phase line, and the first end B 11 of the B-phase secondary winding of the series transformer is connected with the parallel transformer
  • the first output terminal c 1p of the voltage regulating device SM-c1 of the C-phase secondary side is connected, and the second output terminal c 1n of the voltage regulating device SM-c1 of the C-phase secondary side is connected to the voltage regulating device SM-a2 of the A-phase secondary side.
  • the first output terminal a 2p is connected, and the second output terminal a 2n of the voltage regulating device SM-a2 of the A-phase secondary side is connected to the first output terminal b 3p of the voltage regulating device SM-b3 of the B-phase secondary side.
  • the input end of the safety protection auxiliary adjustment device in the C-phase line is connected to the input end of the C-phase line and the input end of the C-phase primary side of the C-phase parallel transformer.
  • the safety protection auxiliary adjustment device in the C-phase line The output terminal is connected to the input terminal of the C-phase primary side of the three-phase series transformer, the output terminal of the C-phase primary side of the three-phase series transformer is connected to the output terminal of the C-phase line, and the first end C 11 of the C-phase secondary winding of the series transformer is connected with the parallel transformer
  • the first output terminal a 1p of the voltage regulating device SM-a1 of the A-phase secondary side is connected, and the second output terminal a 1n of the voltage regulating device SM-a1 of the A-phase secondary side is connected to the voltage regulating device SM-b2 of the B-phase secondary side.
  • the first output terminal b 2p is connected, the second output terminal b 2n of the voltage regulating device SM-b2 of the B-phase secondary side is connected to the first output terminal c 3p of the voltage regulating device SM-c3 of the C-phase secondary side, and the voltage regulation Pack
  • the second output terminal a 3n of SM-a3, the second output terminal b 3n of the voltage regulating device SM-b3 and the second output terminal c 3n of the voltage regulating device SM-c3 are connected to form a second neutral point O'.
  • the contact power supply transformer provided by the embodiment of the present application is provided with a multi-phase parallel transformer, a multi-phase series transformer and multiple safety protection auxiliary regulating devices.
  • the switch bridge arm module provided in the parallel transformer performs vector transformation and synthesis of the input voltage.
  • the first electrical quantity is obtained, and then combined with the safety protection auxiliary adjustment device to actively protect, isolate and adjust the fault, power quality, power and impedance of the contact circuit.
  • the power supply transformer connects the lines, it will not increase the risk of the grid's short-circuit current exceeding the standard due to the line connection.
  • the power supply transformer is used to realize the connection of the lines, which improves the reuse function of the device. , eliminating the need for separate communication devices for line communication, greatly improving the economy and practicality, and making it easy to promote and use.
  • At least one of the primary end and the primary end of the parallel transformer has multiple taps, and the multiple taps are configured to perform voltage stability regulation on the secondary power supply winding of the parallel transformer.
  • at least one of the primary end and the primary end of the parallel transformer has multiple taps.
  • the primary end of the parallel transformer has multiple taps, or the primary end of the parallel transformer has multiple taps, or the primary end of the parallel transformer has multiple taps.
  • Both the head end and the primary side end of the parallel transformer include multiple taps. For the head end with multiple taps, select one of the taps to be connected to the first line. For the end with multiple taps, select one of the taps to be connected to the first line. Neutral point connection.
  • At least one of the primary end and the primary end of the parallel transformer has multiple taps, and the voltage of the secondary power supply winding of the parallel transformer can be adjusted on-load by selecting different taps online.
  • the asymmetric winding includes multiple taps
  • the parallel transformer includes multiple voltage regulating devices
  • the multiple voltage regulating devices include multiple switch bridge arm modules with the same number as the asymmetric windings of the parallel transformer; correspondingly , multiple taps are connected to the input end of the switch arm module; the voltage regulating device controls the bridge arm switch state of the switch arm module to realize the preset strobing of the corresponding multiple taps, thereby realizing multiple Asymmetrical windings of parallel transformers with adjacent phases
  • the first electrical quantity is obtained after the windings are interconnected in a continuous, intermittent or normally on/normally closed electrical working mode.
  • the preset modes include normally on, normally closed and intermittently conductive windings according to a preset frequency.
  • the asymmetric winding taps include a 11 , a 12 and a 13.
  • the switch arm module is composed of multiple bridge arm switches.
  • Phase A is introduced as an example.
  • u 1 and u 2 are the output voltages of the asymmetric winding of the parallel transformer.
  • the winding can also continue to draw multiple taps to output multiple voltages (such as u n ), and each tap of the winding is connected accordingly.
  • the bridge arm switches s a1 and s a2 are closed and other switches are open; or the bridge arm switches s a3 and s a4 are closed and other switches are open; or the bridge arm switches s a5 and s a6 are closed and other switches are open; Or the bridge arm switches s an-1 and s an are closed, the other switches are open, and the output voltages are all 0.
  • multiple voltage regulating devices are provided in the parallel transformer, and the number of switching bridge arm modules is set in the multiple voltage regulating devices to be the same as the number of asymmetric windings of the parallel transformer, thereby achieving the use of a smaller number of windings and taps. And the number of switching devices can achieve more voltage vector adjustment outputs, which greatly improves the range and granularity of the voltage vector adjustment.
  • the secondary side of the multi-phase series transformer also includes a redundant reactor.
  • the redundant reactor is connected to both ends of the secondary winding of the series transformer through a first switch and is configured as Suppress the current that the series transformer needs to withstand for a period longer than the first threshold and a magnitude greater than the fifth threshold during normal operation.
  • the primary side of each phase series transformer in the multi-phase series transformer includes: a third switch and a primary winding. The two ends of the third switch are respectively connected in parallel with the two ends of the primary winding of the series transformer.
  • the multi-phase series transformer The secondary side of each phase series transformer includes: a first inductor, a first switch and a secondary winding.
  • the first inductor and the first switch are connected in series and then connected in parallel with the secondary winding.
  • phase A is taken as an example.
  • the first switch KMa is closed, which is equivalent to connecting the second inductor L ao in parallel to the secondary winding of the series transformer of phase A.
  • the second inductor L ao is added to the primary line after being transformed by the A-phase series transformer according to a certain transformation ratio.
  • the A-phase parallel transformer can stop outputting voltage, which is equivalent to the A-phase series transformer functioning as a current-limiting reactor, which is configured to limit the long-term maximum voltage. Electric current is generated.
  • the third switch k sa is closed.
  • the design of the multi-phase series transformer in this embodiment can adjust the impedance while adjusting the voltage, playing a beneficial role in harmonic blocking of power quality and adjusting the impedance as needed.
  • a third switch is connected in parallel at both ends of the primary side of each series transformer, and the safety protection auxiliary adjustment device includes a first controllable switch s a1 and a second controllable switch s a2 , the third controllable switch s a3 , the fourth controllable switch s a4 , the first capacitor C a1 , the second capacitor C a2 , the first inductor L a , the first resistor ra , the second switch ka and through Voltage absorber FR a .
  • one end of the fourth controllable switch s a4 and the input end of the safety protection auxiliary adjustment device, one end of the first capacitor C a1 , one end of the first controllable switch s a1 , one end of the overvoltage absorber FR a and the second One end of the switch k a is connected, the other end of the fourth controllable switch s a4 is connected to the other end of the first capacitor C a1 and one end of the second capacitor C a2 respectively, and the other end of the second capacitor C a2 is connected to the second controllable switch s a4 respectively.
  • One end of the controllable switch s a2 is connected to one end of the third controllable switch s a3 .
  • the other end of the first controllable switch s a1 is connected to one end of the first inductor L a and one end of the first resistor r a respectively.
  • the first resistor The other end of r a is connected to the other end of the second controllable switch s a2 , the other end of the first inductor L a and the output end of the safety protection auxiliary regulating device, the other end of the overvoltage absorber FR a , the third controllable The other end of the switch s a3 and the other end of the second switch ka are connected.
  • the first controllable switch s a1 , the second controllable switch s a2 , the third controllable switch s a3 and the fourth controllable switch s a4 are switching devices with a bidirectional current conduction function.
  • the switches of each controllable switch The state can be controlled, such as closing a controllable switch or opening a controllable switch.
  • the different working states of each switch correspond to different functions.
  • the overvoltage absorber FR a can absorb voltage under specific circumstances to protect the circuit from overvoltage.
  • the safety protection auxiliary adjustment device When the power supply transformer is operating normally, the third switch is open, the second controllable switch and the fourth controllable switch are closed, the first controllable switch, the third controllable switch and the second switch are open, and the safety protection auxiliary adjustment device It exhibits a harmonic high-resistance characteristic, blocking harmonics higher than the second threshold from passing through the transformer and lines and thus having an adverse impact on the power supply system; when a short-circuit fault occurs between the first line and the second circuit connected to the power supply transformer, the The first controllable switch, the third controllable switch and the fourth controllable switch are closed, the second controllable switch and the second switch are disconnected, and the safety protection auxiliary adjustment device presents a high resistance state with a set bandwidth, which will exceed the third threshold.
  • Line operating voltage drops across the device, or limits fault current to a fourth threshold, configured to protect the series transformer from voltages in excess of the third threshold and currents in excess of the fourth threshold due to line short circuits; polyphase
  • the third switch is closed, the third controllable switch is closed, the second controllable switch, the fourth controllable switch and the second switch are opened, and the first controllable switch is turned on in a specific manner.
  • the safety protection auxiliary adjustment device directly communicates the two lines and presents a
  • the adjustable reactance state of inductive reactance, capacitive reactance, impedance or a combination of the three is configured to adjust the power of the contact point; when the safety protection auxiliary adjustment device stops working or when only the series transformer and the parallel transformer are required to work, the third switch is turned off On, the second switch is closed, the first controllable switch, the second controllable switch, the third controllable switch and the fourth controllable switch are open.
  • the third switch when the connection power supply transformer is operating normally, the third switch is turned off.
  • the third switch includes k sa , k sb and k sc , the second controllable switch s a2 and the fourth controllable switch s a4
  • the first controllable switch s a1 , the third controllable switch s a3 and the second switch ka are closed, the second capacitor C a2 , the first resistor ra and the first inductor L a work in series, and the capacitor and inductor
  • the parameter settings are in a resonant state, and the resonant frequency is the rated operating frequency of the entire transformer; the second threshold is the preset maximum value of harmonics passing through the entire contact transformer, and the first resistor r a can widen the resonant frequency point.
  • the frequency band width can avoid the problem of working in a non-resonant state due to a certain deviation in the working frequency; the safety protection auxiliary adjustment device presents a low impedance state at the rated working frequency, which is equivalent to the original working circuit not changing and not affecting the
  • the first controllable switch s a1 , the third controllable switch s a3 and the fourth controllable switch s a4 need to be closed, the second controllable switch s a2 and the second switch k a Disconnected, at this time, the second capacitor C a2 and the first inductor L a work in parallel.
  • the parameters of the same capacitor and inductor are in a resonant state.
  • the resonant frequency is also the rated operating frequency of the entire transformer.
  • the set bandwidth is high at the rated frequency. resistance state, so that the safety protection auxiliary regulating device can drop a line voltage exceeding a third threshold on itself or limit the fault current to a fourth threshold, and is configured to protect the series transformer from being subjected to more than a third threshold due to the line circuit.
  • the third threshold value is the maximum voltage value that the preset series transformer can withstand.
  • the fourth threshold is the preset maximum current value that the series transformer can withstand. If the voltage exceeds the third threshold, it means that the voltage is too high.
  • the overvoltage absorption device can absorb the excessive voltage to ensure that the voltage at both ends of the series transformer does not become too high, causing It not only protects the transformer, but also actively suppresses fault current.
  • both ends of the primary winding of the series transformer are connected to both ends of the third switch k sa respectively.
  • the first The controllable switch s a1 (for example, a thyristor) works at a specific conduction angle and is in series with the first inductor L a .
  • the third controllable switch s a3 is closed, the third switch k sa is closed, and the second controllable switch s a3 is closed.
  • the switch s a2 , the fourth controllable switch s a4 and the second switch ka are disconnected.
  • the first capacitor C a1 and the second capacitor C a2 are connected in series to form a new equivalent capacitance parameter. At this time, it is connected with the first inductor L a , the branch formed by the first controllable switch s a1 is in a parallel relationship, in which the two capacitors are connected in series to form a new equivalent capacitance parameter in order to form a new impedance point and are configured to support the adjustment of this mode. Setting the first controllable switch s a1 with different conduction angles can provide continuously adjustable capacitance or inductance. Therefore, the safety protection auxiliary adjustment device can be independent of the transformer.
  • This device can directly connect the two lines and can present An adjustable reactance state of inductive reactance, capacitive reactance, impedance, or a combination of the three that can be configured to provide power regulation to the contact point within a certain range. It is realized that under certain circumstances, only the safety protection auxiliary adjusting device is needed to adjust the contact line, avoiding unnecessary working modes of series and parallel transformers, improving device utilization, reducing system losses, and making it easier to apply in engineering.
  • the third switch k sa is opened, the second switch ka is closed, the first controllable switch s a1 , the second controllable switch s a2 , and the third
  • the controllable switch s a3 and the fourth controllable switch s a4 are disconnected, the safety protection auxiliary adjustment device will be deactivated, which facilitates the inspection and maintenance of the device.
  • a first controllable switch, a second controllable switch, a third controllable switch, a fourth controllable switch, a first capacitor, a second capacitor, a first inductor, and a third controllable switch are provided in the safety protection auxiliary adjustment device.
  • a resistor, a second switch and an overvoltage absorber realize power quality isolation by adjusting the switching status of each switch in the safety protection auxiliary adjustment device.
  • the safety protection auxiliary adjustment device can independently
  • the series-parallel transformer directly connects the two lines, and realizes the adjustment of the power of the contact point to a certain extent, saving unnecessary work links of the loop closing device under certain working conditions, and can also instantly achieve high resistance to isolation short circuit faults , can withstand overvoltage for a long time and thereby reduce the overvoltage burnout of the series transformer.
  • the protection and active adjustment function formed in the entire power supply transformer are crucial.
  • the safety protection auxiliary regulating device as a highly integrated multi-functional device, improves the working efficiency of the entire power supply transformer and reduces system losses.
  • the connection type power supply transformer also includes: a fine compensation device and a first bypass switch and a second bypass switch.
  • the input end of the fine compensation device passes through the first bypass switch k n1 and the second bypass switch.
  • the switch k n2 is connected to the secondary output end of the series transformer.
  • the fine compensation device is mainly composed of a four-phenomenon converter with AC-DC conversion or AC-AC conversion function, and is configured to output a continuously changing second electrical quantity. If When the first bypass switch k n1 and the second bypass switch k n2 on the secondary output side of the series transformer are in the off state, the output second electrical quantity is superimposed with the first electrical quantity and then passes through the corresponding secondary side of the series transformer. side coupling to the primary side of the series transformer.
  • the fine compensation device is composed of a typical converter structure.
  • the fine compensation device can be an AC/AC converter or a DC/AC converter, which can be used with an AC adjustable output function.
  • Its wiring method can be a three-phase four-wire system or a three-phase three-wire system. If it is a three-phase four-wire system, its fourth line output can be connected to the second center point O'.
  • the DC source is a device that provides DC, such as a supercapacitor, a battery or various DC power supplies. By controlling six transistors, a continuously changing second electrical quantity can be obtained.
  • the three-phase input terminals of the fine compensation device are connected to the first bypass switch k n1 and the second bypass switch k n2 , and the two bypass switches are controlled to be closed and disconnected according to operational needs, for example, when the fine compensation device is required to work. , disconnect the two bypass switches kn1 and kn2 , and use the pulse width modulation signal to control the switching tube in the fine compensation device to obtain a continuously changing second electrical quantity.
  • the second electrical quantity is superimposed on the first electrical quantity and then passes
  • the secondary side of the corresponding series transformer is coupled to the primary side of the series transformer; when the fine compensation device is not required to work, just close the two bypass switches k n1 and k n2 and stop the fine compensation device at the same time.
  • the embodiment of the present application uses a four-phenomenon converter with AC and DC conversion functions to form a precision
  • the fine compensation device and the DC source can obtain a continuously changing second electrical quantity, and the obtained first electrical quantity and the second electrical quantity can be synthesized and superimposed on the line through the series transformer coupling, and by controlling the input of the fine compensation device and The status of each switching tube can realize continuous smooth adjustment of the fine compensation device, fundamental impedance adjustment, harmonic voltage adjustment and harmonic impedance adjustment.
  • connection type power supply transformer also includes: a grounding device configured to ground the first neutral point O, including a grounding reactor and a grounding resistor connected in series.
  • the grounding reactor The reactance value and the resistance value of the ground resistor are adjustable.
  • the grounding device can ground the first neutral point O after the selected tap at the end of the three-phase primary winding is connected.
  • the grounding device is composed of a reactor L and a resistor R connected in series. The reactance value of the reactor L can be adjusted through the tap. The resistance R The resistance value can be adjusted, and the reactance value and resistance value in the grounding device can be adjusted online according to the needs of parameter setting of the power grid line grounding protection system.
  • the embodiment of the present application can ensure the reliable operation of the transformer and eliminate the need for additional grounding devices that must be added to the substation due to the need for cable line ground fault detection.
  • This application also provides a power supply transformer control method, as shown in Figure 7, which should be configured as the power supply transformer of the above embodiment.
  • the method includes:
  • Step S101 The multi-phase parallel transformer adjusts the switching status of multiple switch bridge arm modules in a continuous, intermittent or normally open/normally closed electrical working mode according to the three-phase input voltage, and outputs the first electrical quantity. Specifically, the switching states of multiple off-bridge arm modules are adjusted in continuous, intermittent or normally on/normally closed electrical working modes according to the three-phase input voltage in the line, and the three-phase parallel transformer outputs the first electrical quantity.
  • Step S102 Adjust the fine compensation device, which outputs a continuously changing second electrical quantity. Specifically, by adjusting the fine compensation device, a second electrical quantity that continuously changes within a certain range can be output.
  • Step S103 The voltage vector generated by superposing the first electrical quantity and the second electrical quantity acts at most The secondary winding of the phase series transformer, the primary winding of the series transformer superimposes the voltage vector coupled from the secondary winding to the three-phase input voltage, forming a voltage difference between the first line and the second line, that is, by adjusting the voltage Differentially realize the mutual transmission of electric energy to the specified power of the contact line.
  • the first electrical quantity and the second electrical quantity are vector transformed and synthesized and then applied to the secondary winding of the multi-phase series transformer.
  • the primary winding of each series transformer superimposes the voltage vector coupled from the secondary winding to the corresponding phase.
  • the voltage vector coupled from the secondary winding forms the voltage difference between the first line and the second line.
  • the three-phase input voltage is vector transformed and synthesized to obtain a first electrical quantity by adjusting the switching bridge arm modules of multiple voltage regulating devices in a multi-phase parallel transformer, and the fine compensation device adjusts and outputs a continuously changing second electrical quantity.
  • the obtained first electrical quantity and the second electrical quantity are synthesized and superimposed on the input voltage through series transformer coupling, achieving continuous stepless and precise adjustment of the device's output electrical quantity and constructing special adjustment functions such as voltage, impedance, and harmonics. .
  • the fine compensation device is adjusted, and the fine compensation device outputs a continuously changing second electrical quantity, including:
  • Step S201 Determine the instruction variable for adjusting the fine compensation device according to the desired voltage vector and the first electrical quantity output by the multi-phase parallel transformer.
  • V ABC is the first electrical quantity output by the parallel transformer switch arm module after interconnection
  • V abc-ref V ABCref - V ABC
  • V abc-ref is used as the command variable of the fine compensation device
  • harmonic impedance adjustment variables can also be added to the desired voltage vector.
  • the expected voltage vector includes voltage smoothing variables, Fundamental impedance variable, harmonic voltage adjustment variable and harmonic impedance adjustment variable, such as voltage smoothing variable V 1ref (because the voltage output by the parallel transformer changes in a step form, this instruction can be to achieve the voltage output by the parallel transformer A variable set to enable continuous smooth adjustment), fundamental impedance variable Z 1ref (a variable set mainly to realize fundamental impedance adjustment), harmonic voltage adjustment variable V href (mainly set to realize harmonic voltage adjustment) A variable set), harmonic impedance adjustment variable Z href (a variable mainly set to achieve harmonic impedance adjustment) and other command variables. Whether multiple commands are required to be superimposed, you can select switches s 1 and s 2 , s 3 ,..., s m to achieve.
  • Step S202 Perform vector frequency division control calculation on the command variable and the output voltage of the fine compensation device, and then combine it with the DC voltage control amount of the fine compensation device to obtain a control signal.
  • the obtained command variables and the output voltage of the fine compensation device are used to perform frequency division calculation processing, and then combined with the DC voltage control quantity output by the fine compensation device, for example, Fourier transform and error control are used to obtain control of fine compensation.
  • Device control signal V ref is used to obtain control of fine compensation.
  • Step S203 Adjust the fine compensation device according to the modulated and converted control signal, and the fine compensation device outputs a continuously changing second electrical quantity.
  • the control signal V ref is pulse width modulated (PWM) to obtain a fine compensation execution signal.
  • the fine compensation execution signal is sent to an actuator inside the fine compensation device to adjust the fine compensation device.
  • the output of the fine compensation device changes continuously. of the second electrical quantity, the desired voltage vector V ABCref can be obtained.
  • the embodiment of the present application uses the desired voltage vector, the first electrical quantity output by the multi-phase parallel transformer, the output voltage of the fine compensation device, and the DC voltage control quantity output by the fine compensation device to determine the control signal based on the vector frequency division control method.
  • the control method can quickly respond to the command and perform frequency domain analytical control on the command at each frequency. It can achieve precise tracking of the command point-to-point. It can not only achieve the output of the desired variable with high precision, but also facilitate resonance. Analysis and early warning, dynamically changing the control gain of each frequency point to avoid high-gain control at the resonance risk point of the system.
  • the desired voltage vector selects voltage smoothing variables, fundamental impedance variables, harmonic voltage adjustment variables and harmonic impedance adjustment variables to achieve continuous smooth adjustment of the voltage output by the parallel transformer, fundamental impedance adjustment, harmonic voltage adjustment and harmonic impedance adjustment. .
  • the command variable and the output voltage of the fine compensation device are calculated for vector frequency division control, and combined with the DC voltage control amount of the fine compensation device, the control signal is obtained, including:
  • Step S301 Fourier transform is performed on the command variable to obtain the command amount at each frequency.
  • the command variable V abc-ref is subjected to positive Fourier transform to obtain command quantities V 1ref , V 2ref , V 1href , etc. at different voltage frequencies.
  • Step S302 Fourier transform the output voltage of the fine compensation device to obtain the actual output at each frequency. Specifically, the output voltage Vabc of the fine compensation device is received, and the output voltage of the fine compensation device is subjected to forward Fourier transform to obtain the actual output quantities V1abc , V2abc , Vhabc , etc. at different voltage frequencies.
  • Step S303 After making a difference between the command quantity and the actual output quantity, the first signal is obtained through error control and inverse Fourier transform. Specifically, after making a difference between the command quantity and the actual output quantity, error control is carried out through G 1 (s), G 2 (s),...G n (s) controllers at each frequency, and each frequency is adjusted to The controller output is subjected to inverse Fourier transformation to obtain the first signal.
  • Step S304 Perform error control and AC conversion on the DC voltage and DC command voltage of the fine compensation device to obtain a second signal.
  • the DC source in the fine compensation device outputs the DC voltage U DC , such as a super capacitor, a battery or various DC power supplies.
  • the DC voltage U DC and the DC command voltage U DCref are passed through the G DC (s) controller . Error control is carried out, and the second signal is obtained through AC signal conversion.
  • the second signal is the DC control quantity U dc .
  • Step S305 Calculate ahead of time based on the first signal, the second signal and the instruction variable.
  • the feedforward amounts obtained are added to obtain the control signal.
  • the control signal V ref is obtained by adding the obtained first signal, the second signal and the feedforward amount obtained by performing advance calculation G v (s) on the command variable V abc-ref .
  • control signal is obtained by Fourier transforming the command variable and the output voltage of the fine compensation device and subjecting it to error control, and then adding the feedforward amount obtained by calculating the command variable in advance through the inverse Fourier transform. , improves the speed of responding to instructions and performing frequency domain analysis and control of instructions at each frequency, and improves the tracking speed and precision of instructions and the accuracy of control signals.

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Abstract

本申请公开一种联络型供电变压器及其调控方法，联络型供电变压器包括：多相并联变压器、多相串联变压器和多个安全防护辅助调节装置，多相并联变压器的原边首端均接入第一线路，并联变压器的副边具有至少一个供电绕组和多个不对称绕组，供电绕组与供电端连接，多个不对称绕组经各自对应的开关桥臂模组分别与相邻相并联变压器副边不对称绕组进行互联之后得到第一电气量，第一电气量通过对应串联变压器的副边耦合至串联变压器的原边，多个安全防护辅助调节装置串联连接于第一线路与第二线路之间。本申请实现将第一线路和第二线路的电能传输至供电端，并将第一线路和第二线路进行联络和指定功率的电能互传输。

Description

一种联络型供电变压器及其调控方法
相关申请的交叉引用
本申请基于申请号为202211092917.X、申请日为2022年09月08日,申请名称为“一种联络型供电变压器及其调控方法”的中国专利申请提出，并要求该中国专利申请的优先权，该中国专利申请的全部内容在此以引入方式并入本申请。
技术领域
本申请涉及电力系统领域，具体涉及一种联络型供电变压器及其调控方法。
背景技术
电网作为多种能源的基础承载网，其能否安全、稳定、可靠运行直接影响新能源的接纳、用户的供电质量等。我国配电网主要运行于“闭环设计，开环运行”的方式，面对分布式新能源发电的大量接入，因其表现出的发电出力随机性、间歇性及波动性较强，导致了开环运行的配电网电压大幅波动、反向潮流过载、环网运行难等问题，同时现在配电网也面临着增容难、配电设备及线路利用率低等突出问题，这些问题有碍于“碳达峰，碳中和”目标的推进。
为了应对上述问题，亟需建立电网的重构能力，打通电网线路与线路之间的断开点，也就是实现配电闭环运行，提升配电网对新能源的承载力，最大化接纳新能源。而配电网实现闭环运行的核心技术就是柔性合环技术，即通过特定装置将合环点两侧的线路进行物理连接，并利用控制手段实现对流过合环点的功率进行控制，结合各线路的剩余容量来优化线路互济传输容量从而提升电网线路的承载力，尽可能高效消纳新能源和提升电网资 源利用率。然而现有技术路线均通过额外增加柔性合环装备来实现上述目标，并且装备多采用“背靠背”电力电子技术方案，如电力电子变压器、能量路由器、软开关(soft open point，SOP)、柔性多状态开关等，这些技术形成的柔性合环装备不仅存在造价高、损耗大、可靠性低、维护难等系列问题，而且需要额外增加占地去设置该装备，因配电网合环需求点多面广，因此现有技术存在实用化程度不高、运行复杂、推广难的问题。
发明内容
有鉴于此，本申请提供一种联络型供电变压器及其调控方法，以解决造价高、损耗大、可靠性低、维护难、额外占地大等实用化程度不高，运行复杂、推广难的问题。
本申请提出的技术方案如下、
本申请实施例提供了一种联络型供电变压器，被配置为将电网线路的第一线路和第二线路的电能传输至供电端，并将所述第一线路和所述第二线路进行联络和指定功率的电能互传输，所述联络型供电变压器包括多相并联变压器、多相串联变压器和多个安全防护辅助调节装置；所述多相并联变压器的原边首端均接入所述第一线路，原边末端相连接形成第一中性点；所述并联变压器的副边具有至少一个供电绕组和多个不对称绕组，所述供电绕组与所述供电端连接，所述多个不对称绕组经各自对应的开关桥臂模组分别与相邻相并联变压器副边不对称绕组对应的桥臂模组进行互联之后得到第一电气量，所述第一电气量通过对应串联变压器的副边耦合至所述串联变压器的原边，以接入所述第二线路；所述多个安全防护辅助调节装置串联连接于所述第一线路与第二线路之间，被配置为对所述第一线路和所述第二线路进行电能质量阻隔和故障隔离、对所述第一线路和所述第二线路的联络功率动态调节以及对所述多相串联变压器进行线路故障保护。
本申请实施例提供的联络型供电变压器，设置多相并联变压器、多相串联变压器以及多个安全防护辅助调节装置，其中，并联变压器中设置的开关桥臂模组将输入电压进行矢量变换和合成得到第一电气量，再结合安全防护辅助调节装置对联络回路的故障、电能质量、功率、阻抗进行主动防护阻隔和调节。并且该供电变压器对线路进行联络时，不会因线路联络后而增加电网的短路电流超标风险，同时兼容传统线路的继电保护系统，借助供电变压器实现线路的联络，提升了装置的复用功能，节省了为线路联络而单独设置的联络装置，大大提升了经济性和实用程度，易于推广使用。
在一些实施例中，所述并联变压器原边首端和原边末端至少之一具有多个抽头，所述多个抽头被配置为对所述并联变压器的副边供电绕组电压进行稳定调节。
本申请实施例通过设置并联变压器原边首端和原边末端至少之一具有多个抽头，可以通过不断电方式选择不同的抽头实现对并联变压器的副边供电绕组电压的稳定调节。
在一些实施例中，所述不对称绕组包括多个抽头，所述并联变压器包括多个调压装置，所述多个调压装置包括与所述并联变压器的不对称绕组数量相同的多个开关桥臂模组；相应的，所述多个抽头连接所述开关桥臂模组的输入端；所述调压装置通过控制所述开关桥臂模组的桥臂开关状态实现对相应的所述多个抽头的预设方式选通，实现将所述多个不对称绕组分别与相邻相的并联变压器的不对称绕组以连续、断续或常通/常闭电气工作方式进行互联之后得到第一电气量，所述预设方式包括常通、常闭以及按照预设频率进行断续导通绕组。
本申请实施例通过在并联变压器设置多个调压装置，且在多个调压装置中设置与并联变压器的不对称绕组数量相同的开关桥臂模组，实现采用较少的绕组数量、抽头数量以及开关器件数量就能实现较多的电压矢量调 节输出，极大提升了调节电压矢量的范围和颗粒度。
在一些实施例中，所述多相串联变压器的原边分别串联于所述第一线路和所述第二线路之间；所述串联变压器的副边输入端与两个相邻相的并联变压器的不对称绕组以及本相并联变压器的不对称绕组依次通过开关桥臂模组连接，本相并联变压器的不对称绕组对应的开关桥臂绕组的一个输出端连接至第二中性点。
在一些实施例中，所述多相串联变压器的副边还包括冗余电抗器，所述冗余电抗器通过一开关连接于所述串联变压器副边绕组的两端，被配置为抑制所述串联变压器正常工作时承受的时长大于第一阈值、大小大于第五阈值的电流。
在一些实施例中，每相串联变压器的原边两端并联第三开关，所述安全防护辅助调节装置包括第一可控开关、第二可控开关、第三可控开关、第四可控开关、第一电容、第二电容、第一电感、第一电阻、第一开关及过电压吸收器，其中，所述供电变压器正常工作时，所述第三开关断开，所述第二可控开关和所述第四可控开关闭合，所述第一可控开关、所述第三可控开关以及所述第二开关断开，所述安全防护辅助调节装置呈现出一种谐波高阻特性，阻隔高于第二阈值的谐波经过变压器以及线路进而对供电系统产生的不利影响；所述供电变压器接入的第一线路和第二线路发生短路故障时，所述第一可控开关、所述第三可控开关和所述第四可控开关闭合，所述第二可控开关和所述第二开关断开，所述安全防护辅助调节装置呈现设定带宽的高阻状态，将超过第三阈值的线路工作电压降落在该装置上，或将故障电流限制在第四阈值以内，被配置为保护串联变压器免受因线路短路而承受的超过第三阈值的电压和超过第四阈值的电流的影响；所述多相并联变压器和多相串联变压器不工作时，所述第三开关闭合，所述第三可控开关闭合，所述第二可控开关、所述第四可控开关以及所述第二开关断开，所述第一可控开关以特定导通角或频率工作，所述安全防护 辅助调节装置将两线路进行直接联络，并呈现一种感抗、容抗、阻抗或三者组合的可调电抗状态，被配置为对联络功率的调节；所述安全防护辅助调节装置停止工作时或者仅需要串联变压器和并联变压器工作时，所述第三开关断开，所述第二开关闭合，所述第一可控开关、第二可控开关、第三可控开关、第四可控开关断开。
本申请实施例通过在安全防护辅助调节装置中设置第一可控开关、第二可控开关、第三可控开关、第四可控开关、第一电容、第二电容、第一电感、第一电阻、第二开关及过电压吸收器，通过调节安全防护辅助调节装置中各开关的开关状态实现电能质量阻隔，安全防护辅助调节装置可独立于串并联变压器将两线路直接联络，并在一定程度上实现对联络点功率的调节，节省了合环装置在某些工况时不必要的工作环节，还可以瞬间实现高抗隔离短路故障，可以长时间耐受过电压进而减少串联变压器的过压烧毁，在整个供电变压器中形成的防护和主动调节作用至关重要。由此，该安全防护辅助调节装置作为多功能装置集成于所述联络型供电变压器中，提升了整个供电变压器的工作效率，降低了系统损耗。
在一些实施例中，所述联络型供电变压器还包括：精细补偿装置以及第一旁路开关和第二旁路开关，所述精细补偿装置的输入端通过所述第一旁路开关、所述第二旁路开关与所述串联变压器的副边输出端连接，所述精细补偿装置由具有交-直变换或者交-交变换功能的四现象变流器构成，被配置为输出连续变化的第二电气量，当所述第一旁路开关和第二旁路开关处于断开状态，则将所述第二输出电压与所述第一电气量叠加之后通过相对应的串联变压器的副边耦合所述串联变压器的原边。
本申请实施例通过利用具有交直流变换功能的四现象变流器构成的精细补偿装置及直流源可以获得连续变化的第二电气量，可以实现将得到的第一电气量和第二电气量合成经串联变压器耦合叠加到线路上。
在一些实施例中，所述联络型供电变压器还包括：接地装置，被配置 为将所述第一中性点接地，包括串联连接的接地电抗器和接地电阻，所述接地电抗器的电抗值和接地电阻的电阻值可调节。
本申请实施例通过在供电变压器设置可调节的接地装置，可以保障变压器的运行可靠，可省去因电缆线路接地故障检测需求而必须在变电站增加的额外接地装置。
本申请提供了一种供电变压器调控方法，应被配置为上述本申请实施例所述的供电变压器，所述方法包括：并联变压器根据三相输入电压以连续、断续或者常通/常闭的电气工作方式调节多个开关桥臂模组的开关状态，输出第一电气量；调节精细补偿装置，所述精细补偿装置输出连续变化的第二电气量；将所述第一电气量和所述第二电气量叠加生成的电压矢量作用至多相串联变压器的副边绕组，串联变压器的原边绕组将副边绕组耦合来的电压矢量叠加至三相输入电压上，形成第一线路和第二线路之间的压差，通过调节所述压差实现对联络线路指定功率的电能互传输。
本申请实施例通过调节多相并联变压器中多个调压装置的开关桥臂模组将三相输入电压进行矢量变换和合成得到第一电气量，精细补偿装置调节输出连续变化的第二电气量，将得到的第一电气量和第二电气量合成经串联变压器耦合叠加到输入电压上，实现了对装置输出电气量的连续无级精确调节以及构建电压、阻抗、谐波等特殊的调节功能。
在一些实施例中，调节所述精细补偿装置，所述精细补偿装置输出连续变化的第二电气量，包括：根据期望电压矢量和所述并联变压器输出的第一电气量确定调节所述精细补偿装置的指令变量；将所述指令变量、所述精细补偿装置的输出电压进行矢量分频控制计算，再结合所述精细补偿装置的直流电压控制量，得到控制信号；根据调制变换后的控制信号调节所述精细补偿装置，所述精细补偿装置输出连续变化的第二电气量。
本申请实施例利用期望电压矢量、三相并联变压器输出的第一电气量、精细补偿装置的输出电压、以及精细补偿装置输出的直流电压基于矢量分 频控制方式确定控制信号，根据控制信号调节所述精细补偿装置输出连续变化的第二电气量，该控制方法可快速响应指令并在各个频率上分别对指令进行频域解析控制，点对点实现指令的精确跟踪，不仅可高精度实现期望变量的输出，而且可便于谐振分析和预警，动态改变各个频点的控制增益，避免在系统的谐振风险点处进行高增益控制。
在一些实施例中，将所述指令变量、所述精细补偿装置的输出电压进行矢量分频控制计算，再结合所述精细补偿装置的直流电压控制量，得到控制信号，包括：将所述指令变量进行傅里叶变换，得到各个频次上的指令量；将所述精细补偿装置的输出电压进行傅里叶变换，得到各个频次上的实际输出量；将所述指令量和所述实际输出量作差后通过误差控制和逆傅里叶变换得到第一信号；将所述精细补偿装置输出的直流电压和直流指令通过误差控制和交流变换得到第二信号；根据所述第一信号、第二信号以及将所述指令变量进行超前计算得到的前馈量相加，得到控制信号。
本申请实施例通过将指令变量和精细补偿装置的输出电压进行傅里叶变换后经过误差控制，再通过傅里叶逆变换后与将指令变量进行超前计算得到的前馈量相加得到控制信号，提高了在各个频率上分别对指令进行频域解析控制的速度，提升指令的跟踪速度、精度和控制信号的准确度。
在一些实施例中，所述期望电压矢量包括：电压平滑变量、基波阻抗变量、谐波电压调节变量以及谐波阻抗调节变量。
本申请实施例期望电压矢量选择电压平滑变量、基波阻抗变量、谐波电压调节变量以及谐波阻抗调节变量可实现精细补偿装置的连续平滑调节、基波阻抗调节、谐波电压调节及谐波阻抗调节等。
附图说明
为了更清楚地说明本申请具体实施方式或现有技术中的技术方案，下面将对具体实施方式或现有技术描述中所需要使用的附图作简单地介绍， 显而易见地，下面描述中的附图是本申请的一些实施方式，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为现有技术中提供的一种柔性合环技术路线结构图；
图2为本申请实施例提供的一种柔性合环技术路线结构图；
图3为本申请实施例提供的一种联络供电变压器的拓扑结构图；
图4为本申请实施例提供的一种多相并联变压器的拓扑结构图；
图5为本申请实施例提供的一种调压装置的拓扑结构图；
图6为本申请实施例提供的一种安全防护辅助调节装置的拓扑结构图；
图7为本申请实施例提供的一种供电变压器调控方法的流程图；
图8为本申请实施例提供的一种供电变压器调控方法的流程图；
图9为本申请实施例提供的一种供电变压器调控方法的流程图；
图10为本申请实施例提供的一种供电变压器调控方法的流程图。
具体实施方式
下面将结合附图对本申请的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
在本申请的描述中，需要说明的是，术语“中心”、“上”、“下”、“左”、“右”、“竖直”、“水平”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。此外，术语“第一”、“第二”、“第三”仅被配置为描述目的，而不能理解为指示或暗示相对重要性。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术 语“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，还可以是两个元件内部的连通，可以是无线连接，也可以是有线连接。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本申请中的具体含义。
此外，下面所描述的本申请不同实施方式中所涉及的技术特征只要彼此之间未构成冲突就可以相互结合。
正如在背景技术中所述，现有技术中的柔性合环线路大多需要额外增加柔性合环装置，其具体线路结构如图1所示，是在两路线路之间通过设置柔性合环装置来实现A线路和B线路的合环运行。然而采用柔性合环装备不仅存在造价高、损耗大、可靠性低、维护难等系列问题，而且需要额外增加占地去设置该装备。
因此针对现有合环装备存在的问题，本申请公开了一种具有柔性合环功能的联络型供电变压器，该供电变压器不仅能实现传统的供电功能而且也能就近对合环点两侧的线路进行柔性合环。该供电变压器在线路中的连接关系如图2所示。通过对现有的台区变压器进行改造升级即可直接得到该具有柔性合环功能的联络型供电变压器。由此，本申请实施例提供的供电变压器不需要额外增加占地，仅通过供电变压器自身就能实现柔性合环，并且可以实现对流过合环点处的功率进行柔性调节，也具有主动对电网的故障进行安全防护、阻隔电能质量、大冲击电流耐受负荷转供等优势，因此更易工程推广解决诸多现有配电网问题，具有经济性好、实用性高、创新性强，并且具有可靠性高、损耗低、易维护等优点。
本申请实施例了提供一种联络型供电变压器，如图3所示，联络型供电变压器被配置为将电网线路的第一线路和第二线路的电能传输至供电端，并将第一线路和第二线路进行联络和指定功率的电能互传输，联络型供电变压器包括多相并联变压器、多相串联变压器和多个安全防护辅助调节装 置；多相并联变压器的原边首端均接入第一线路，原边末端相连接形成第一中性点；并联变压器的副边具有至少一个供电绕组和多个不对称绕组，供电绕组与供电端连接，多个不对称绕组经各自对应的开关桥臂模组分别与相邻相并联变压器副边不对称绕组对应的桥臂模组进行互联之后得到第一电气量，第一电气量通过对应串联变压器的副边耦合至串联变压器的原边，以接入第二线路；多个安全防护辅助调节装置串联连接于第一线路与第二线路之间，被配置为对第一线路和第二线路进行电能质量阻隔和故障隔离、对第一线路和第二线路的联络功率动态调节以及对多相串联变压器进行线路故障保护。
多相串联变压器的原边分别串联于第一线路和第二线路之间；串联变压器的副边输入端与两个相邻相的并联变压器的不对称绕组以及本相并联变压器的不对称绕组依次通过开关桥臂模组连接，本相并联变压器的不对称绕组对应的开关桥臂模组的一个输出端连接至第二中性点。
示例性地，本申请实施例中的联络型供电变压器可以实现第一线路向第二线路传输电能，也可以实现第二线路向第一线路传输电能，也可以实现第一线路和(或)第二线路向供电端传输电能。不对称绕组的设置可以实现用较少抽头实现较多的调节步长和较好的调节精度。
在本申请的实施例中，如图3所示，各相并联变压器的原边末端相连接形成第一中性点O，供电绕组的供电端口U、V、W可以向负载供电，可实现单相供电或三相供电，加上端口N可以实现三相四线制供电。联络功率动态调节是指根据第一线路的传输容量和第二线路的传输容量，确定：将第一线路的功率向第二线路转移满足要求的功率、将第二线路的功率向第一线路转移满足要求的功率、或第一线路和第二线路同时向供电端(U、V、W)供电。
在本申请的实施例中，多相并联变压器的结构如图3和图4所示，图3为联络供电变压器的拓扑图，包括多相并联变压器，图4则为图3联络供 电变压器包括的多相并联变压器，多相并联变压器分别为A、B、C相并联变压器，多相串联变压器分别为A、B、C相串联变压器，如图3和图4所示，A相线路中安全防护辅助调节装置的输入端连接A相线路的输入端及A相并联变压器的A相原边的输入端，A相线路中安全防护辅助调节装置的输出端连接三相串联变压器的A相原边的输入端，三相串联变压器的A相原边的输出端连接A相线路的输出端，串联变压器A相副边绕组的首端A11与并联变压器B相副边的调压装置SM-b1的第一输出端b1p连接，B相副边的调压装置SM-b1的第二输出端b1n与C相副边的调压装置SM-c2的第一输出端c2p连接，C相副边的调压装置SM-c2的第二输出端c2n与A相副边的调压装置SM-a3的第一输出端a3p连接。
如图3和图4所示，B相线路中安全防护辅助调节装置的输入端连接B相线路的输入端及B相并联变压器的B相原边的输入端，B相线路中安全防护辅助调节装置的输出端连接三相串联变压器的B相原边的输入端，三相串联变压器的B相原边的输出端连接B相线路的输出端，串联变压器B相副边绕组的首端B11与并联变压器C相副边的调压装置SM-c1的第一输出端c1p连接，C相副边的调压装置SM-c1的第二输出端c1n与A相副边的调压装置SM-a2的第一输出端a2p连接，A相副边的调压装置SM-a2的第二输出端a2n与B相副边的调压装置SM-b3的第一输出端b3p连接。
如图3和图4所示，C相线路中安全防护辅助调节装置的输入端连接C相线路的输入端及C相并联变压器的C相原边的输入端，C相线路中安全防护辅助调节装置的输出端连接三相串联变压器的C相原边的输入端，三相串联变压器的C相原边的输出端连接C相线路的输出端，串联变压器C相副边绕组的首端C11与并联变压器A相副边的调压装置SM-a1的第一输出端a1p连接，A相副边的调压装置SM-a1的第二输出端a1n与B相副边的调压装置SM-b2的第一输出端b2p连接，B相副边的调压装置SM-b2的第二输出端b2n与C相副边的调压装置SM-c3的第一输出端c3p连接，调压装 置SM-a3的第二输出端a3n、调压装置SM-b3的第二输出端b3n和调压装置SM-c3的第二输出端c3n连接形成第二中性点O’。
本申请实施例提供的联络型供电变压器，设置多相并联变压器、多相串联变压器以及多个安全防护辅助调节装置，其中，并联变压器中设置的开关桥臂模组将输入电压进行矢量变换和合成得到第一电气量，再结合安全防护辅助调节装置对联络回路的故障、电能质量、功率、阻抗进行主动防护阻隔和调节。并且该供电变压器对线路进行联络时，不会因线路联络后而增加电网的短路电流超标风险，同时兼容传统线路的继电保护系统，借助供电变压器实现线路的联络，提升了装置的复用功能，节省了为线路联络而单独设置的联络装置，大大提升了经济性和实用程度，易于推广使用。
在本申请的实施例中，并联变压器原边首端和原边末端至少之一具有多个抽头，多个抽头被配置为对并联变压器的副边供电绕组进行电压稳定调节。具体地，并联变压器原边首端和原边末端至少其中之一具有多个抽头，例如，并联变压器原边首端具有多个抽头，或者并联变压器原边末端具有多个抽头，或者并联变压器原边首端和并联变压器原边末端都包括多个抽头，对于具有多个抽头的首端，选择其中一个抽头与第一线路相连接，对于具有多个抽头的末端，选择其中一个抽头与第一中性点连接。
本申请实施例通过设置并联变压器原边首端和原边末端至少之一具有多个抽头，可以通过在线选择不同的抽头实现对并联变压器副边供电绕组电压的有载调节。
在本申请的实施例中，不对称绕组包括多个抽头，并联变压器包括多个调压装置，多个调压装置包括与并联变压器的不对称绕组数量相同的多个开关桥臂模组；相应的，多个抽头连接开关桥臂模组的输入端；调压装置通过控制开关桥臂模组的桥臂开关状态实现对相应的多个抽头的预设方式选通，由此实现将多个不对称绕组分别与相邻相的并联变压器的不对称 绕组以连续、断续或常通/常闭电气工作方式进行互联之后得到第一电气量，所述预设方式包括常通、常闭以及按照预设频率进行断续导通绕组。
示例性地，如图4所示，以A相为例，不对称绕组抽头包括a11、a12及a13，如图5所示，开关桥臂模组由多个桥臂开关组成，以A相为例进行介绍，假设u1和u2分别为并联变压器不对称绕组的输出电压，该绕组也可以继续抽出多个抽头输出多个电压(如un)，绕组每个抽头对应接入一个桥臂，开关桥臂模组的输出端子anp和ann之间有多种不同的输出电压状态，例如当n＝3时，有13种输出电压矢量：
(1)桥臂开关sa1和sa4闭合，其它开关断开，输出电压为u1；
(2)桥臂开关sa3和sa6闭合，其它开关断开，输出电压为u2；
(3)桥臂开关sa5和san闭合，其它开关断开，输出电压为un；
(4)桥臂开关sa1和sa6闭合，其它开关断开，输出电压为u1+u2；
(5)桥臂开关sa3和san闭合，其它开关断开，输出电压为u2+un；
(6)桥臂开关sa1和san闭合，其它开关断开，输出电压为u1+u2+un；
(7)桥臂开关sa2和sa3闭合，其它开关断开，输出电压为-u1；
(8)桥臂开关sa4和sa5闭合，其它开关断开，输出电压为-u2；
(9)桥臂开关sa6和san-1闭合，其它开关断开，输出电压为-un；
(10)桥臂开关sa2和sa5闭合，其它开关断开，输出电压为-(u1+u2)；
(11)桥臂开关sa4和san-1闭合，其它开关断开，输出电压为-(u2+un)；
(12)桥臂开关sa2和san-1闭合，其它开关断开，输出电压为﹣(u1+u2+un)；
(13)桥臂开关sa1和sa2闭合，其它开关断开；或者桥臂开关sa3和sa4闭合，其它开关断开；或者桥臂开关sa5和sa6闭合，其它开关断开；或者桥臂开关san-1和san闭合，其它开关断开，输出电压均为0。
相邻相的开关桥臂模组输出的电压和本相开关桥臂模组输出的电压在幅值和相位上均具有一定的差异，因此不同相的开关桥臂模组输出的电压叠加之后，就能实现对输入电压幅值和相位的多种调节效果。例如，n＝3 时，每相使用1个绕组，每个绕组有3个电压等级，对本相1个开关桥臂模组和相邻相的2个开关桥臂绕组串联组合后，就可实现13×13×13＝2197种矢量输出。
本申请实施例通过在并联变压器设置多个调压装置，且在多个调压装置中设置与并联变压器的不对称绕组数量相同的开关桥臂模组，实现采用较少的绕组数量、抽头数量以及开关器件数量就能实现较多的电压矢量调节输出，极大提升了调节电压矢量的范围和颗粒度。
在本申请的实施例中，如图3所示，多相串联变压器的副边还包括冗余电抗器，冗余电抗器通过第一开关连接于串联变压器副边绕组的两端，被配置为抑制串联变压器正常工作时需要承受的时长大于第一阈值、大小大于第五阈值的电流。在一具体实施例中，多相串联变压器中每相串联变压器原边包括：第三开关和原边绕组，第三开关的两端分别与串联变压器原边绕组的两端并联，多相串联变压器中每相串联变压器副边包括：第一电感、第一开关和副边绕组，第一电感和第一开关串联后与副边绕组并联连接。在本申请实施例中，以A相为例进行阐述，需要限流运行时，第一开关KMa闭合，相当于将第二电感Lao并联到A相串联变压器副边绕组上，第二电感Lao经A相串联变压器按一定变比变换后加在原边线路上，此时A相并联变压器可以停止输出电压，相当于A相串联变压器呈现一个限流电抗器的功能，被配置为限制长时间大电流产生。当不需要串联变压器工作时，闭合第三开关ksa。
本实施例多相串联变压器的设计，可实现电压调节的同时对阻抗进行调节，起到电能质量谐波阻隔的有益作用，以及按需调节阻抗的需求。
在本申请的实施例中，如图3和图6所示，每个串联变压器的原边两端并联第三开关，安全防护辅助调节装置包括第一可控开关sa1、第二可控开关sa2、第三可控开关sa3、第四可控开关sa4、第一电容Ca1、第二电容Ca2、第一电感La、第一电阻ra、第二开关ka及过电压吸收器FRa。
其中，第四可控开关sa4的一端和安全防护辅助调节装置的输入端、第一电容Ca1的一端、第一可控开关sa1的一端、过电压吸收器FRa的一端及第二开关ka的一端连接，第四可控开关sa4的另一端分别与第一电容Ca1的另一端及第二电容Ca2的一端连接，第二电容Ca2的另一端分别与第二可控开关sa2的一端及第三可控开关sa3的一端连接，第一可控开关sa1的另一端分别与第一电感La的一端及第一电阻ra的一端连接，第一电阻ra的另一端与第二可控开关sa2的另一端连接，第一电感La的另一端和安全防护辅助调节装置的输出端、过电压吸收器FRa的另一端、第三可控开关sa3的另一端及第二开关ka的另一端连接。
其中，第一可控开关sa1、第二可控开关sa2、第三可控开关sa3和第四可控开关sa4为具有双向电流导通功能的开关器件，各可控开关的开关状态可以控制，例如闭合某个可控开关或断开某个可控开关，各开关不同的工作状态对应不同的功能，过电压吸收器FRa可以在特定情况下吸收电压进而保护电路过电压。
其中，供电变压器正常工作时，第三开关断开，第二可控开关和第四可控开关闭合，第一可控开关、第三可控开关以及第二开关断开，安全防护辅助调节装置呈现出一种谐波高阻特性，阻隔高于第二阈值的谐波经过变压器以及线路进而对供电系统产生的不利影响；供电变压器接入的第一线路和第二电路发生短路故障时，第一可控开关、第三可控开关和第四可控开关闭合，第二可控开关和第二开关断开，安全防护辅助调节装置呈现设定带宽的高阻状态，将超过第三阈值的线路工作电压降落在该装置上，或将故障电流限制在第四阈值以内，被配置为保护串联变压器免受因线路短路而承受的超过第三阈值的电压和超过第四阈值的电流；多相并联变压器和多相串联变压器不工作时，第三开关闭合，第三可控开关闭合，第二可控开关、第四可控开关以及第二开关断开，第一可控开关以特定导通角或频率工作，安全防护辅助调节装置将两线路进行直接联络，并呈现一种 感抗、容抗、阻抗或三者组合的可调电抗状态，被配置为对联络点功率的调节；安全防护辅助调节装置停止工作时或者仅需要串联变压器和并联变压器工作时，第三开关断开，第二开关闭合，第一可控开关、第二可控开关、第三可控开关、第四可控开关断开。
在本申请的实施例中，联络型供电变压器正常工作时，第三开关断开，第三开关包括ksa、ksb及ksc，第二可控开关sa2和第四可控开关sa4闭合，第一可控开关sa1、第三可控开关sa3以及第二开关ka断开时，第二电容Ca2、第一电阻ra、第一电感La串联工作，并且电容电感的参数设置呈现为谐振状态，谐振频率为整个变压器的额定工作频率；第二阈值为预先设置的经过整个联络型变压器的谐波的最大值，第一电阻ra可以加宽谐振频率点处的频带宽度，能避免工作频率存在一定的偏移而导致工作在非谐振状态的问题；安全防护辅助调节装置在额定工作频率时呈现低阻抗状态，相当于原有的工作回路不发生改变，不影响变压器的柔性合环调节需求，而在额定工作频率之外的其他频段，呈现一种谐波高阻特性，可有效阻隔高于第二阈值的谐波经过变压器以及线路进而对供电系统产生不利的影响，极大提升了变压器的工作可靠性和自身的电能质量。
在本申请的实施例中，供电变压器接入的第一电路和第二线路发生短路故障时(如接地故障，如果不做特殊处理，等同于线路的工作电压将全部加到串联变压器上，将对变压器系统造成极大的危害)，需将第一可控开关sa1、第三可控开关sa3和第四可控开关sa4闭合，第二可控开关sa2和第二开关ka断开，此时第二电容Ca2、第一电感La并联工作，同样电容电感的参数呈现为谐振状态，谐振频率也为整个变压器的额定工作频率，在额定频率处呈现设定带宽的高阻状态，因此安全防护辅助调节装置可将超过第三阈值的线路电压降落在自身上或将故障电流限制在第四阈值以内，被配置为保护串联变压器免受因线路电路而承受的超过第三阈值的电压和超过第四阈值的电流，第三阈值为预设的串联变压器承受的最大电压值，第 四阈值为预设的串联变压器承受的最大电流值，如果电压超过第三阈值，代表电压过大，过电压吸收装置可将过大的电压吸收，保证串联变压器两端的电压不发生过高，起到对变压器的保护作用，同样也起到了对故障电流的主动抑制。
在本申请的实施例中，以A相为例，串联变压器的原边绕组的两端分别与第三开关ksa的两端连接，多相并联变压器和多相串联变压器不工作时，第一可控开关sa1(例如为晶闸管)以特定的导通角进行工作，并且和第一电感La是串联关系，第三可控开关sa3闭合、第三开关ksa闭合，第二可控开关sa2、第四可控开关sa4及第二开关ka断开，第一电容Ca1和第二电容Ca2串联后形成一个新的等效电容参数，此时与第一电感La、第一可控开关sa1形成的支路是并联关系，其中，两电容串联后形成一个新的等效电容参数，是为了形成一个新的阻抗点，被配置为支持该模式的调节实现。设置第一可控开关sa1不同的导通角，可呈现连续可调的容性或者感性，因此，安全防护辅助调节装置可以独立于变压器，该装置可以将两个线路直接联络，并可呈现一种感抗、容抗、阻抗或三者组合的可调电抗状态，可以在一定范围内被配置为对联络点进行功率调节。实现了特定情况下仅需要安全防护辅助调节装置对联络线路进行调节即可，避免了串并联变压器不必要的工作模式，提高装置利用率，降低系统损耗，更易工程应用。
安全防护辅助调节装置停止工作时或者仅需要串并联变压器工作时，第三开关ksa断开，第二开关ka闭合，第一可控开关sa1、第二可控开关sa2、第三可控开关sa3、第四可控开关sa4断开，则安全防护辅助调节装置退出使用，便于装置的检修维护。
本申请实施例通过在安全防护辅助调节装置中设置第一可控开关、第二可控开关、第三可控开关、第四可控开关、第一电容、第二电容、第一电感、第一电阻、第二开关及过电压吸收器，通过调节安全防护辅助调节装置中各开关的开关状态实现电能质量阻隔，安全防护辅助调节装置可独 立于串并联变压器将两线路直接联络，并在一定程度上实现对联络点功率的调节，节省了合环装置在某些工况时不必要的工作环节，还可以瞬间实现高抗隔离短路故障，可以长时间耐受过电压进而减少串联变压器的过压烧毁，在整个供电变压器中形成的防护和主动调节作用至关重要。由此，该安全防护辅助调节装置作为高度集成化的多功能装置，提升了整个供电变压器的工作效率，降低了系统损耗。
在本申请的实施例中，联络型供电变压器还包括：精细补偿装置以及第一旁路开关和第二旁路开关，精细补偿装置的输入端经过第一旁路开关kn1、第二旁路开关kn2与串联变压器的副边输出端连接，精细补偿装置主要由具有交-直变换或者交-交变换功能的四现象变流器构成，被配置为输出连续变化的第二电气量，如果串联变压器副边输出侧的第一旁路开关kn1和第二旁路开关kn2处于断开状态，则将输出的第二电气量与第一电气量叠加之后通过相对应的串联变压器的副边耦合串联变压器的原边。在一具体实施例中，如图9所示，精细补偿装置由典型变流器结构构成。
示例性地，精细补偿装置可以是AC/AC变换器，也可以是DC/AC变换器，具有交流可调输出功能即可使用，其接线方式可以是三相四线制或者三相三线制，如果是三相四线制，其第四线输出可以与第二中心点O’进行连接。直流源为提供直流的器件，例如超容、电池或各种直流电源，控制六个晶体管可以得到连续变化的第二电气量。精细补偿装置的三相输入端之间与第一旁路开关kn1、第二旁路开关kn2连接，根据运行需要控制这两个旁路开关闭合与断开，例如需要精细补偿装置工作时，断开两个旁路开关kn1、kn2，利用脉冲宽度调制信号控制精细补偿装置中的开关管可以得到连续变化的第二电气量，将第二电气量与第一电气量叠加之后通过相对应的串联变压器的副边耦合串联变压器的原边；不需要精细补偿装置工作时，闭合两个旁路开关kn1、kn2，同时停止精细补偿装置即可。
本申请实施例通过利用具有交直流变换功能的四现象变流器构成的精 细补偿装置及直流源可以获得连续变化的第二电气量，可以实现将得到的第一电气量和第二电气量合成经串联变压器耦合叠加到线路上，并且，通过控制精细补偿装置的输入以及各个开关管的状态，能够实现精细补偿装置的连续平滑调节、基波阻抗调节、谐波电压调节及谐波阻抗调节。
在本申请的实施例中，如图4所示，联络型供电变压器还包括：接地装置，被配置为将第一中性点O接地，包括串联连接的接地电抗器和接地电阻，接地电抗器的电抗值和接地电阻的电阻值可调节。
示例性地，在并联变压器原边绕组的末端抽出多个抽头形成一个稳压调节环节，选择不同的抽头即可改变原副边的变比；原边绕组首端是每相的电压输入端，接地装置可以将三相原边绕组末端所选择的抽头相连后的第一中性点O接地，接地装置由电抗器L和电阻R串联构成，电抗器L的电抗值可通过抽头调节，电阻R的电阻值可以调节，根据电网线路接地保护系统参数设置的需要可对接地装置中的电抗值和电阻值进行在线调节。
本申请实施例通过在供电变压器设置可调节的接地装置，可以保障变压器的运行可靠，可省去因电缆线路接地故障检测需求而必须在变电站增加的额外接地装置。
本申请还提供一种供电变压器调控方法，如图7所示，应被配置为上述实施例的供电变压器，该方法包括：
步骤S101、多相并联变压器根据三相输入电压以连续、断续或者常通/常闭的电气工作方式调节多个开关桥臂模组的开关状态，输出第一电气量。具体地，根据线路中的三相输入电压以连续、断续或者常通/常闭的电气工作方式调节多个关桥臂模组的开关状态，三相并联变压器输出第一电气量。
步骤S102、调节精细补偿装置，精细补偿装置输出连续变化的第二电气量。具体地，通过调节精细补偿装置可以输出在某个范围连续变化的第二电气量。
步骤S103、将第一电气量和第二电气量叠加生成的电压矢量作用至多 相串联变压器的副边绕组，串联变压器的原边绕组将副边绕组耦合来的电压矢量叠加至三相输入电压上，形成第一线路和第二线路之间的压差，即通过调节该压差实现对联络线路指定功率的电能互传输。具体地，将第一电气量和第二电气量进行矢量变换与合成后作用至多相串联变压器的副边绕组，各个串联变压器的原边绕组将副边绕组耦合来的电压矢量叠加到对应各相输入电压上，副边绕组耦合来的电压矢量形成第一线路和第二线路的压差，通过调节串联变压器副边绕组耦合来的的电压矢量即压差可以实现对联络线路指定功率的电能互传输。
本申请实施例通过调节多相并联变压器中多个调压装置的开关桥臂模组将三相输入电压进行矢量变换和合成得到第一电气量，精细补偿装置调节输出连续变化的第二电气量，将得到的第一电气量和第二电气量合成经串联变压器耦合叠加到输入电压上，实现了对装置输出电气量的连续无级精确调节以及构建电压、阻抗、谐波等特殊的调节功能。
在一些实施例中，如图8所示，调节精细补偿装置，精细补偿装置输出连续变化的第二电气量，包括：
步骤S201、根据期望电压矢量和多相并联变压器输出的第一电气量确定调节精细补偿装置的指令变量。假设VABC为并联变压器开关桥臂模组互联后输出的第一电气量，如果需要在串联变压器副边绕组上得到一个期望电压矢量VABCref(此电压与整个装备的输入电压叠加后就是实现联络运行需要的调节电压)，则需要使精细补偿装置输出的电压为Vabc-ref＝VABCref﹣VABC；(Vabc-ref则作为精细补偿装置的指令变量)；因此，将期望电压矢量和多相并联变压器输出的第一电气量作差即可确定调节精细补偿装置的指令变量。此时，期望电压矢量包括电压平滑变量。
此外，若需要精细补偿装置实现阻抗、谐波等调节时，还可以在期望电压矢量中加入基波阻抗变量、谐波电压调节变量以及谐波阻抗调节变量。
在本申请的实施例中，如图9所示，期望电压矢量包括电压平滑变量、 基波阻抗变量、谐波电压调节变量以及谐波阻抗调节变量，如包括电压平滑变量V1ref(因为并联变压器输出的电压是以台阶形式变化的，所以该指令可以是为了实现并联变压器输出的电压能够连续平滑调节而设置的一种变量)、基波阻抗变量Z1ref(主要为了实现基波阻抗调节而设置的一种变量)、谐波电压调节变量Vhref(主要为了实现谐波电压调节而设置的一种变量)、谐波阻抗调节变量Zhref(主要为了实现谐波阻抗调节而设置的一种变量)及其它指令变量，是否需要多种指令叠加，可通过选择开关s1、s2、s3、……、sm来实现。
在确定指令变量时，由于期望电压矢量中的一些变量不属于电压矢量，需要将不属于电压矢量的变量进行转换为电压矢量的计算，例如将基波阻抗变量Z1ref和谐波阻抗调节变量Zhref经过Gz1(s)和Gzh(s)控制器计算得到可以相应的电压矢量，将得到的各种电压矢量相加后得到一个期望电压矢量VABCref。
步骤S202、将指令变量、精细补偿装置的输出电压进行矢量分频控制计算，再结合精细补偿装置的直流电压控制量，得到控制信号。具体地，利用获得的指令变量、精细补偿装置的输出电压进行分频次的计算处理，再结合精细补偿装置输出的直流电压控制量，例如采用傅里叶变换和误差控制等以获得控制精细补偿装置的控制信号Vref。
步骤S203、根据调制变换后的控制信号调节精细补偿装置，精细补偿装置输出连续变化的第二电气量。具体地，控制信号Vref经脉冲宽度调制(pulse width modulation，PWM)后得到精细补偿执行信号，将精细补偿执行信号发送至精细补偿装置内部的执行机构调节精细补偿装置，精细补偿装置输出连续变化的第二电气量，即可得到期望的电压矢量VABCref。
本申请实施例利用期望电压矢量、多相并联变压器输出的第一电气量、精细补偿装置的输出电压、以及精细补偿装置输出的直流电压控制量基于矢量分频控制方式确定控制信号，根据控制信号调节精细补偿装置输出连 续变化的第二电气量，该控制方法可快速响应指令并在各个频率上分别对指令进行频域解析控制，点对点实现指令的精确跟踪，不仅可高精度实现期望变量的输出，而且可便于谐振分析和预警，动态改变各个频点的控制增益，避免在系统的谐振风险点处进行高增益控制。期望电压矢量选择电压平滑变量、基波阻抗变量、谐波电压调节变量以及谐波阻抗调节变量可实现并联变压器输出的电压能够连续平滑调节、基波阻抗调节、谐波电压调节及谐波阻抗调节。
如图10所示，将指令变量、精细补偿装置的输出电压进行矢量分频控制计算，以及结合精细补偿装置的直流电压控制量，得到控制信号，包括：
步骤S301、将指令变量进行傅里叶变换，得到各个频次上的指令量。在一具体实施例中，将指令变量Vabc-ref进行正傅里叶变换，得到不同电压频次上的指令量V1ref、V2ref、V1href等。
步骤S302、将精细补偿装置的输出电压进行傅里叶变换，得到各个频次上的实际输出量。具体地，接收精细补偿装置的输出电压Vabc，将精细补偿装置的输出电压进行傅里叶正变换，得到不同电压频次上的实际输出量V1abc、V2abc、Vhabc等。
步骤S303、将指令量和实际输出量作差后通过误差控制和逆傅里叶变换得到第一信号。具体地，将指令量和实际输出量作差后，在每个频次上通过G1(s)、G2(s)、……Gn(s)控制器进行误差控制，将每个频次上的控制器输出量进行逆傅里叶变换，得到第一信号。
步骤S304、将所述精细补偿装置的直流电压和直流指令电压进行误差控制和交流变换得到第二信号。具体地，精细补偿装置中直流源输出直流电压UDC，例如超容、电池或各种直流电源输出直流电压UDC，将直流电压UDC和直流指令电压UDCref通过GDC(s)控制器进行误差控制，再通过交流信号变换得到第二信号，第二信号即直流控制量Udc。
步骤S305、根据第一信号、第二信号以及将指令变量进行超前计算得 到的前馈量相加，得到控制信号。具体地，将得到的第一信号、第二信号以及将指令变量Vabc-ref进行超前计算Gv(s)得到的前馈量相加得到控制信号Vref。
本申请实施例通过将指令变量和精细补偿装置的输出电压进行傅里叶变换后经过误差控制，再通过傅里叶逆变换后与将指令变量进行超前计算得到的前馈量相加得到控制信号，提高了响应指令和在各个频率上分别对指令进行频域解析控制的速度，提升指令的跟踪速度、精度和控制信号的准确度。
虽然关于示例实施例及其优点已经详细说明，但是本领域技术人员可以在不脱离本申请的精神和所附权利要求限定的保护范围的情况下对这些实施例进行各种变化、替换和修改，这样的修改和变型均落入由所附权利要求所限定的范围之内。对于其他例子，本领域的普通技术人员应当容易理解在保持本申请保护范围内的同时，工艺步骤的次序可以变化。
此外，本申请的应用范围不局限于说明书中描述的特定实施例的工艺、机构、制造、物质组成、手段、方法及步骤。从本申请的公开内容，作为本领域的普通技术人员将容易地理解，对于目前已存在或者以后即将开发出的工艺、机构、制造、物质组成、手段、方法或步骤，其中它们执行与本申请描述的对应实施例大体相同的功能或者获得大体相同的结果，依照本申请可以对它们进行应用。因此，本申请所附权利要求旨在将这些工艺、机构、制造、物质组成、手段、方法或步骤包含在其保护范围内。

Claims (12)

  1. 一种联络型供电变压器，被配置为将电网线路的第一线路和第二线路的电能传输至供电端，并将所述第一线路和所述第二线路进行联络和指定功率的电能互传输，所述联络型供电变压器包括多相并联变压器、多相串联变压器和多个安全防护辅助调节装置；
    所述多相并联变压器的原边首端均接入所述第一线路，原边末端相连接形成第一中性点；
    所述并联变压器的副边具有至少一个供电绕组和多个不对称绕组，所述供电绕组与所述供电端连接，所述多个不对称绕组经各自对应的开关桥臂模组分别与相邻相并联变压器副边不对称绕组对应的桥臂模组进行互联之后得到第一电气量，所述第一电气量通过对应串联变压器的副边耦合至所述串联变压器的原边，以接入所述第二线路；
    所述多个安全防护辅助调节装置串联连接于所述第一线路与第二线路之间，被配置为对所述第一线路和所述第二线路进行电能质量阻隔和故障隔离、对所述第一线路和所述第二线路的联络功率动态调节以及对所述多相串联变压器进行线路故障保护。
  2. 根据权利要求1所述的联络型供电变压器，其中，所述并联变压器原边首端和原边末端至少之一具有多个抽头，所述多个抽头被配置为对所述并联变压器的副边供电绕组电压进行稳定调节。
  3. 根据权利要求1所述的联络型供电变压器，其中，所述不对称绕组包括多个抽头，所述并联变压器包括多个调压装置，所述多个调压装置包括与所述并联变压器的不对称绕组数量相同的多个开关桥臂模组；相应的，
    所述多个抽头连接所述开关桥臂模组的输入端；
    所述调压装置通过控制所述开关桥臂模组的桥臂开关状态实现对相应的所述多个抽头的预设方式选通，实现将所述多个不对称绕组分别与相邻 相的并联变压器的不对称绕组以连续、断续或常通/常闭电气工作方式进行互联之后得到第一电气量，所述预设方式包括常通、常闭以及按照预设频率进行断续导通绕组。
  4. 根据权利要求1所述的联络型供电变压器，其中，所述多相串联变压器的原边分别串联于所述第一线路和所述第二线路之间；
    所述串联变压器的副边输入端与两个相邻相的并联变压器的不对称绕组以及本相并联变压器的不对称绕组依次通过开关桥臂模组连接，本相并联变压器的不对称绕组对应的开关桥臂模组的一个输出端连接至第二中性点。
  5. 根据权利要求1所述的联络型供电变压器，其中，所述串联变压器的副边还包括冗余电抗器，所述冗余电抗器通过第一开关连接于所述串联变压器副边绕组的两端，被配置为抑制所述串联变压器正常工作时承受的时长大于第一阈值、大小大于第五阈值的电流。
  6. 根据权利要求1所述的联络型供电变压器，其中，每相串联变压器的原边两端并联第三开关，所述安全防护辅助调节装置包括第一可控开关、第二可控开关、第三可控开关、第四可控开关、第一电容、第二电容、第一电感、第一电阻、第二开关及过电压吸收器，其中，
    所述供电变压器正常工作时，所述第三开关断开，所述第二可控开关和所述第四可控开关闭合，所述第一可控开关、所述第三可控开关以及所述第二开关断开，所述安全防护辅助调节装置呈现出一种谐波高阻特性，阻隔高于第二阈值的谐波经过变压器以及线路进而对供电系统产生的不利影响；
    所述供电变压器接入的第一线路和第二线路发生短路故障时，所述第一可控开关、所述第三可控开关和所述第四可控开关闭合，所述第二可控开关和所述第二开关断开，所述安全防护辅助调节装置呈现设定带宽的高阻状态，将超过第三阈值的线路电压降落在该装置上，或将故障电流限制 在第四阈值以内，被配置为保护串联变压器免受因线路短路而承受的超过第三阈值的电压和超过第四阈值的电流影响；
    所述多相并联变压器和多相串联变压器不工作时，所述第三开关闭合，所述第三可控开关闭合，所述第二可控开关、所述第四可控开关以及所述第二开关断开，所述第一可控开关以特定导通角或者开关频率工作，所述安全防护辅助调节装置将两线路进行直接联络，并呈现一种感抗、容抗、阻抗或三者组合的可调电抗状态，被配置为对联络功率的调节；
    所述安全防护辅助调节装置停止工作时或者仅需要串联变压器和并联变压器工作时，所述第三开关断开，所述第二开关闭合，所述第一可控开关、第二可控开关、第三可控开关、第四可控开关断开。
  7. 根据权利要求1所述的联络型供电变压器，其中，所述联络型供电变压器还包括：
    精细补偿装置以及第一旁路开关和第二旁路开关，所述精细补偿装置的输入端通过所述第一旁路开关、所述第二旁路开关与所述串联变压器的副边输出端连接，所述精细补偿装置由具有交-直或交-交变换功能的四现象变流器构成，被配置为输出连续变化的第二电气量，当所述第一旁路开关和第二旁路开关处于断开状态，则将所述第二电气量与所述第一电气量叠加之后通过对应串联变压器的副边耦合至所述串联变压器的原边。
  8. 根据权利要求1所述的联络型供电变压器，其中，所述联络型供电变压器还包括：
    接地装置，被配置为将所述第一中性点接地，接地装置包括串联连接的接地电抗器和接地电阻，所述接地电抗器的电抗值和接地电阻的电阻值可调节。
  9. 一种联络型供电变压器调控方法，其中，应被配置为权利要求7或8所述的供电变压器，所述方法包括：
    并联变压器根据三相输入电压以连续、断续或者常通/常闭的电气工作 方式调节多个开关桥臂模组的开关状态，输出第一电气量；
    调节精细补偿装置，所述精细补偿装置输出连续变化的第二电气量；
    将所述第一电气量和所述第二电气量叠加生成的电压矢量作用至串联变压器的副边绕组，串联变压器的原边绕组将副边绕组耦合来的电压矢量叠加至三相输入电压上，形成第一线路和第二线路之间的压差，通过调节所述压差实现对联络线路指定功率的电能互传输。
  10. 根据权利要求9所述的联络型供电变压器调控方法，其中，调节精细补偿装置，所述精细补偿装置输出连续变化的第二电气量，包括：
    根据期望电压矢量和所述并联变压器输出的第一电气量确定调节所述精细补偿装置的指令变量；
    将所述指令变量、所述精细补偿装置的输出电压进行矢量分频控制计算，再结合所述精细补偿装置的直流电压控制量，得到控制信号；
    根据调制变换后的控制信号调节所述精细补偿装置，所述精细补偿装置输出连续变化的第二电气量。
  11. 根据权利要求10所述的联络型供电变压器调控方法，其中，将所述指令变量、所述精细补偿装置的输出电压进行矢量分频控制计算，再结合所述精细补偿装置的直流电压控制量，得到控制信号，包括：
    将所述指令变量进行傅里叶变换，得到各个频次上的指令量；
    将所述精细补偿装置的输出电压进行傅里叶变换，得到各个频次上的实际输出量；
    将所述指令量和所述实际输出量作差后通过误差控制和逆傅里叶变换得到第一信号；
    将所述精细补偿装置的直流电压和直流指令电压进行误差控制和交流变换得到第二信号；
    根据所述第一信号、第二信号以及将所述指令变量进行超前计算得到的前馈量相加，得到控制信号。
  12. 根据权利要求10所述的联络型供电变压器调控方法，其中，所述期望电压矢量包括：电压平滑调节变量、基波阻抗变量、谐波电压调节变量以及谐波阻抗调节变量。
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