Composite voltage regulation device and control method and device thereof

Abstract

The invention relates to a composite voltage regulation device and a control method and device thereof, a first incoming line connection port is connected with the head end of the primary side of a parallel transformer, three phases of the tail end of the primary side of the parallel transformer are connected to form a neutral point, each phase of the secondary side of the parallel transformer comprises a plurality of secondary windings, each secondary winding comprises three taps, and the taps are connected with the primary side of the parallel transformer. The taps are connected to the secondary side of the series transformer through a voltage regulating mechanism and an on-load voltage regulating switch in sequence, and the two ends of the primary side of the series transformer are connected with a second incoming line connecting port and the head end of the primary side of the parallel transformer respectively; and the control protection device is used for controlling the conduction state of the voltage regulating mechanism and / or the connection relation between the on-load tap changer and each gear of the secondary side of the series transformer based on the real-time power at the wire inlet of the composite voltage regulating device and the received power flow transfer instruction. According to the scheme, the requirements of the power flow adjustment precision and the power flow adjustment range are met through online adjustment, and then the dynamic voltage adjustment requirement of the power distribution network is met.

Description

Technical Field

[0001] The present invention relates to the technical field of AC voltage regulation in distribution networks, and in particular to a composite voltage regulation device and a control method and device thereof. Background Art

[0002] Distributed photovoltaic and electric vehicle charging facilities are connected to the power system on a large scale. The distribution network has evolved from a unidirectional passive network to an active network with multiple elements of source, grid, load and storage. The reverse power transmission causes some distribution transformers and lines to be overloaded in reverse, and the voltage deviation, harmonics and other indicators are affected to a certain extent. The bidirectional over-limit problem of seasonal load voltage such as low voltage in weak grid areas, high voltage in high cable rate areas, coal-to-electricity and well access is more prominent. The above voltage problem also shows a new characteristic of dynamic random change. In addition, the voltage regulation means of my country's distribution network are relatively single, mainly based on the voltage regulation of the substation bus, resulting in large differences in feeder characteristics, and unable to achieve independent voltage regulation decoupled from the bus; the voltage amplitude difference at the feeder contact point is too large, and it is impossible to achieve phase angle regulation and constrain the closed-loop transfer power flow. Especially after the operation mode of the distribution network line is adjusted, the existing all-power electronic interconnection devices, phase-shifting transformers or sen-type transformers are difficult to adjust the power flow regulation accuracy online. It is necessary to readjust the parameters of the device to meet the requirements of power flow regulation accuracy and power flow regulation range, and then meet the dynamic voltage regulation needs of the distribution network.

[0003] In response to these problems existing in the distribution network, it is necessary to study the dynamic voltage regulation technology of the distribution network, improve the refined voltage regulation method, enhance the efficient and reliable power supply capacity of the distribution network and its carrying capacity for distributed resources, and improve the adaptive response capability after the adjustment of the line operation mode, in order to meet the needs of distributed new energy power generation, electric vehicles and industrial clusters for large-scale access to the distribution network. Summary of the invention

[0004] In order to overcome the above defects, the present invention proposes a composite voltage regulating device and a control method and device thereof.

[0005] In a first aspect, a composite voltage regulator is provided, the composite voltage regulator comprising:

[0006] A first incoming line connection port, a second incoming line connection port, a parallel transformer, a voltage regulating mechanism, a series transformer, an on-load voltage regulating switch and a control and protection device;

[0007] The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of two substations of the distribution network;

[0008] The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, the three phases of the tail end of the primary side of the parallel transformer constitute a neutral point, each phase of the secondary side of the parallel transformer includes multiple secondary windings, each secondary winding includes three taps, and each tap is connected to the secondary side of the series transformer in turn through a voltage regulating mechanism and an on-load tap-changing switch, and the two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer;

[0009] The control and protection device is used to control the conduction state of the voltage regulating mechanism and the connection relationship between the on-load voltage regulating switch and each gear on the secondary side of the series transformer based on the real-time power at the incoming line of the composite voltage regulating device and the received power flow transfer instruction.

[0010] Preferably, the first incoming line connection port and the second incoming line connection port are respectively connected to a first voltage collection device and a second voltage collection device for collecting the voltage value required for the control protection device to calculate the real-time power at the incoming line of the composite voltage regulation device; the first incoming line connection port and the second incoming line connection port are respectively connected to a first current collection device and a second current collection device for collecting the current value required for the control protection device to calculate the real-time power at the incoming line of the composite voltage regulation device.

[0011] Furthermore, a first switch is connected between the first incoming line connection port and the first current collection device, and a second switch is connected between the second incoming line connection port and the first current collection device.

[0012] Preferably, the voltage regulating mechanism includes a power valve corresponding to the secondary winding on the secondary side of the parallel transformer, the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding, and the power valve corresponding to the secondary winding of each phase of the secondary side of the parallel transformer is taken, and the outputs of the three power valves are connected in series end to end to form a power valve group, the front end of the power valve group is connected to the front end of the secondary side of the series transformer, and the tail end of the power valve group is connected to an on-load voltage regulating switch.

[0013] Furthermore, the power valve includes three pairs of thyristors connected in positive and negative parallel.

[0014] Preferably, the secondary side of the series transformer includes a plurality of taps, each of which corresponds to a tap of the on-load tap changer.

[0015] Furthermore, the secondary side of the series transformer includes four taps, and the corresponding transformation ratios are 0.5:1, 1:1, 1.5:1 and 2:1 respectively.

[0016] Preferably, each phase of the secondary side of the parallel transformer includes three secondary windings.

[0017] Furthermore, the control and protection device is specifically used for: when the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction exceeds 500kW, by sending a pulse signal for controlling the on and off of the thyristors in each power valve to the voltage regulating mechanism, until the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction does not exceed 500kW.

[0018] Furthermore, the control and protection device is specifically used to record the transfer power flow step length corresponding to the compensation voltage output by the voltage regulating mechanism after each adjustment of the conduction state of the voltage regulating mechanism; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment exceeds 300kW, the on-load voltage regulating switch is controlled to be adjusted down one gear; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment does not exceed -300kW, the on-load voltage regulating switch is controlled to be adjusted up one gear.

[0019] In a second aspect, a control method for a composite voltage regulator is provided, the control method for the composite voltage regulator comprising: controlling the conduction state of the voltage regulating mechanism and / or the connection relationship between the on-load voltage regulating switch and each gear on the secondary side of the series transformer based on the real-time power at the incoming line of the composite voltage regulator and the received power flow transfer instruction through a control protection device.

[0020] Preferably, when the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction exceeds 500kW, the conduction state of each tap of the secondary winding on the secondary side of the connected transformer is adjusted by sending a pulse signal to the voltage regulating mechanism to control the on and off of the thyristors in each power valve by the user, until the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction does not exceed 500kW.

[0021] Furthermore, the transfer power flow step length corresponding to the compensation voltage output by the voltage regulating mechanism is recorded each time the conduction state of the voltage regulating mechanism is adjusted; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment exceeds 300kW, the on-load voltage regulating switch is controlled to lower one gear; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment does not exceed -300kW, the on-load voltage regulating switch is controlled to increase one gear.

[0022] In a third aspect, a computer device is provided, comprising: one or more processors;

[0023] The processor is configured to execute one or more programs;

[0024] When the one or more programs are executed by the one or more processors, the control method of the composite voltage regulating device is implemented.

[0025] In a fourth aspect, a computer-readable storage device is provided, on which a computer program is stored, and when the computer program is executed, the control method of the composite voltage regulating device is implemented.

[0026] The above one or more technical solutions of the present invention have at least one or more of the following beneficial effects:

[0027] The present invention provides a composite voltage regulation device and a control method and device thereof, comprising: the first incoming line connection port and the second incoming line connection port are respectively connected to the outgoing lines of two substations of the distribution network; the first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer constitute the neutral point, each phase of the secondary side of the parallel transformer includes multiple secondary windings, each secondary winding includes three taps, and each tap is connected to the secondary side of the series transformer in turn through a voltage regulating mechanism and an on-load tap-changing switch, and the two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer; the control and protection device is used to control the conduction state of the voltage regulating mechanism and\or the connection relationship between the on-load tap-changing switch and each gear of the secondary side of the series transformer based on the real-time power at the incoming line of the composite voltage regulation device and the received power flow transfer instruction. The technical solution provided by the present invention can meet the requirements of power flow regulation accuracy and power flow regulation range through online regulation, thereby meeting the dynamic voltage regulation requirements of the distribution network, specifically:

[0028] The composite voltage regulating device provided by the present invention adopts a series-parallel structure, and the series side adopts a multi-tap series transformer with an on-load voltage regulator topology. After the line operation mode changes, the adjustment accuracy of the device deteriorates or the flow adjustment range narrows. By comparing the flow transfer step lengths in the two flow transfer processes, it is judged whether the line operation mode has changed, and then according to the change of the flow transfer step length, it is judged whether the on-load voltage regulator is upshifted or downshifted, that is, the transformation ratio of the series transformer is changed, thereby improving the adjustment accuracy of the device or the flow adjustment range. The device does not need to be shut down, and does not need to be manually adjusted. Parameters, so it will not cause load power outages. The control method of its adaptive line operation mode is simple, reliable, and easy to implement. The composite voltage regulating device has good reliability, high technical and economic efficiency, is easy to maintain, has high practicality, and has wide promotion value and engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the main structure of a composite voltage regulator according to an embodiment of the present invention;

[0030] Figure 2It is a main structural schematic diagram of the voltage regulating mechanism of an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] As disclosed in the background technology, distributed photovoltaic and electric vehicle charging facilities are connected to the power system on a large scale, and the distribution network has evolved from a unidirectional passive network to an active network with multiple elements of source, network, load and storage coexisting. The power reverse transmission causes some distribution transformers and lines to be reversely overloaded, and indicators such as voltage deviation and harmonics are affected to a certain extent; the problem of bidirectional over-limit of seasonal load voltage such as low voltage in weak grid areas, high voltage in high cable rate areas, coal-to-electricity and well access is more prominent, and the above-mentioned voltage problem also shows a new characteristic of dynamic random change; in addition, the voltage regulation means of my country's distribution network are relatively single, mainly based on substation bus voltage regulation, resulting in large differences in feeder characteristics, and unable to achieve decoupling and independent voltage regulation from the bus; the voltage harmonic problem is prominent, and it is impossible to suppress voltage harmonics and oscillations; the voltage amplitude difference and angle difference at the feeder contact point are too large, and it is impossible to achieve phase angle regulation and constrain the closed-loop power supply flow. Especially after the operation mode of the distribution network lines is adjusted, it is difficult for the existing all-power electronic interconnection devices, phase-shift transformers or SEN-type transformers to adaptively adjust the power flow regulation accuracy online. It is necessary to readjust the parameters of the device to meet the requirements of power flow regulation accuracy and power flow regulation range, and thus meet the dynamic voltage regulation needs of the distribution network.

[0034] In response to these problems existing in the distribution network, it is necessary to study the dynamic voltage regulation technology of the distribution network, improve the refined voltage regulation method, enhance the efficient and reliable power supply capacity of the distribution network and its carrying capacity for distributed resources, and improve the adaptive response capability after the adjustment of the line operation mode, in order to meet the needs of distributed new energy power generation, electric vehicles and industrial clusters for large-scale access to the distribution network.

[0035] In order to improve the above problems, the present invention provides a composite voltage regulation device and a control method and device thereof, including: the first incoming line connection port and the second incoming line connection port are respectively connected to the outgoing lines of two substations of the distribution network; the first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer constitute the neutral point, and each phase of the secondary side of the parallel transformer includes multiple secondary windings, each secondary winding includes three taps, and each tap is connected to the secondary side of the series transformer in turn through a voltage regulating mechanism and an on-load tap-changing switch, and the two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer; the control and protection device is used to control the conduction state of the voltage regulating mechanism and\or the connection relationship between the on-load tap-changing switch and each gear of the secondary side of the series transformer based on the real-time power at the incoming line of the composite voltage regulation device and the received power transfer instruction. The technical solution provided by the present invention can meet the requirements of power regulation accuracy and power regulation range through online regulation, thereby meeting the dynamic voltage regulation requirements of the distribution network, specifically:

[0036] The composite voltage regulating device provided by the present invention adopts a series-parallel structure, and the series side adopts a multi-tap series transformer with an on-load voltage regulator topology. After the line operation mode changes, the adjustment accuracy of the device deteriorates or the flow adjustment range narrows. By comparing the flow transfer step lengths in the two flow transfer processes, it is judged whether the line operation mode has changed, and then according to the change of the flow transfer step length, it is judged whether the on-load voltage regulator is upshifted or downshifted, that is, the transformation ratio of the series transformer is changed, thereby improving the adjustment accuracy of the device or the flow adjustment range. The device does not need to be shut down, and does not need to be manually adjusted. Parameters, so it will not cause load power outages. The control method of its adaptive line operation mode is simple, reliable, and easy to implement. The composite voltage regulating device has good reliability, high technical and economic efficiency, is easy to maintain, has high practicality, and has wide promotion value and engineering application value.

[0037] Example 1

[0038] See attached Figure 1 , Figure 1 FIG. 1 is a schematic diagram of the main structure of a composite voltage regulator according to an embodiment of the present invention. Figure 1 As shown, the composite voltage regulating device in the embodiment of the present invention mainly includes: a first incoming line connection port, a second incoming line connection port, a parallel transformer ST1, a voltage regulating mechanism GL, a series transformer ST2, an on-load voltage regulating switch YZTY and a control and protection device;

[0039] The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of two substations of the distribution network, for example Figure 1 Incoming line 1 and incoming line 2;

[0040] The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, the three phases of the tail end of the primary side of the parallel transformer are connected to form a neutral point, each phase of the secondary side of the parallel transformer includes multiple secondary windings, each secondary winding includes three taps, and each tap is connected to the secondary side of the series transformer in turn through a voltage regulating mechanism and an on-load tap-changing switch, and the two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer;

[0041] The control and protection device is used to control the conduction state of the voltage regulating mechanism and the connection relationship between the on-load voltage regulating switch and each gear on the secondary side of the series transformer based on the real-time power at the incoming line of the composite voltage regulating device and the received power flow transfer instruction.

[0042] In this embodiment, the first incoming line connection port and the second incoming line connection port are respectively connected to a first voltage acquisition device PT1 and a second voltage acquisition device PT2; the first incoming line connection port and the second incoming line connection port are respectively connected to a first current acquisition device CT1 and a second current acquisition device CT2.

[0043] In one embodiment, a first switch BK1 is connected between the first incoming line connection port and the first current collection device, and a second switch BK2 is connected between the second incoming line connection port and the first current collection device.

[0044] In this embodiment, the voltage regulating mechanism includes a power valve corresponding to the secondary winding on the secondary side of the parallel transformer, and the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding. A power valve corresponding to the secondary winding is taken for each phase of the secondary side of the parallel transformer, and the outputs of the three power valves are connected in series end to end to form a power valve group. The head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to an on-load voltage regulating switch.

[0045] In one embodiment, the power valve includes three pairs of thyristors connected in parallel.

[0046] The function of the voltage regulating mechanism is to take the secondary winding voltage of the three-phase parallel transformer, reorganize and integrate it, obtain a compensation voltage, and connect it to the series transformer. The specific selection of the secondary winding voltage is to control the opening and closing of the thyristor in the power valve so that the power valve works in different gears, thereby obtaining the voltage of different secondary windings of the parallel transformer.

[0047] Connection relationship: Figure 2As shown, each phase of the parallel transformer has three secondary windings, each secondary winding has three taps, and there are 9 secondary windings in total for the three phases. The voltage regulating mechanism has 9 power valves in total, and each secondary winding corresponds to a power valve; the power valve is composed of three pairs of positive and negative thyristors, and the three taps of each secondary winding of the parallel transformer are connected to the three inputs of a power valve in the voltage regulating mechanism. Take 1 A-phase power valve, 1 B-phase power valve, and 1 C-phase power valve respectively, and connect the outputs of the three power valves in series. The first end of the series connection is connected to the first end of the series transformer, and the tail ends of the series connection are connected to form the neutral of the star connection, and are connected to the common end of the on-load voltage regulator.

[0048] In this embodiment, the secondary side of the series transformer includes multiple taps, and each tap corresponds to a tap of the on-load tap changer.

[0049] In one embodiment, the secondary side of the series transformer includes four taps, and the corresponding transformation ratios are 0.5:1, 1:1, 1.5:1 and 2:1 respectively.

[0050] For example, the on-load tap-changing switch YZTY is connected to the secondary side of the series transformer, and has four gears, wherein gear 1 corresponds to a transformation ratio of 0.5:1 of the series transformer ST2, gear 2 corresponds to a transformation ratio of 1:1 of the series transformer ST2, gear 3 corresponds to a transformation ratio of 1.5:1 of the series transformer ST2, and gear 4 corresponds to a transformation ratio of 2:1 of the series transformer ST2.

[0051] In this embodiment, each phase of the secondary side of the parallel transformer includes three secondary windings.

[0052] In one embodiment, the principle of the control protection device is as follows:

[0053] When the line operation mode remains unchanged, the parameters of the line and the device remain unchanged, so the voltage regulating mechanism of the device synthesizes a certain voltage, and the corresponding line flow is also certain. However, when the operation mode of the interconnected line changes, the parameters of the line also change accordingly. At this time, the voltage regulating mechanism synthesizes the same voltage, and when it is connected in series to the line, the transferred flow presented is different from that before the line operation mode changes. For example, after the line operation mode changes, the two interconnected lines are shorter than before, so if the adjustment is one gear, the transferred flow will be larger than the original transferred flow, that is, the step length of the composite voltage regulating device to transfer the flow becomes larger, and the accuracy of the flow regulation will become worse. The accuracy of the flow regulation can be adjusted by adjusting the gear of the on-load voltage regulator and then changing the transformation ratio of the series transformer. If the two interconnected lines are longer than before after the line operation mode changes, then the transferred current will be smaller than the original transferred current by adjusting one gear, that is, the step size of the composite voltage regulating device transferring the current becomes smaller. At this time, the accuracy of the current regulation becomes better, but the range of the current regulation becomes narrower. That is to say, originally adjusted to the maximum gear, 3MW can be adjusted. After the line becomes longer, when the closing device is adjusted to the maximum gear, the actual transferred current will be less than 3MW. By adjusting the gear of the on-load voltage regulator, the ratio of the series transformer is changed to adjust the adjustment range of the device. The control method of the adaptive line operation mode described in the present invention can solve the above problems, and there is no need to stop the closing device in this process, and there is no need to manually adjust the parameters. All adaptive operations are completed automatically.

[0054] Therefore, the control and protection device is specifically used for: when the difference between the real-time power at the incoming line of the composite voltage regulation device and the power flow corresponding to the received power flow transfer instruction exceeds 500kW, by sending a pulse signal for controlling the on and off of the thyristors in each power valve to the voltage regulation mechanism, until the difference between the real-time power at the incoming line of the composite voltage regulation device and the power flow corresponding to the received power flow transfer instruction does not exceed 500kW.

[0055] In one embodiment, the control and protection device is specifically used to record the transfer power flow step length corresponding to the compensation voltage output by the voltage regulating mechanism after each adjustment of the conduction state of the voltage regulating mechanism; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment exceeds 300kW, the on-load voltage regulating switch is controlled to be adjusted down one gear; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment does not exceed -300kW, the on-load voltage regulating switch is controlled to be adjusted up one gear.

[0056] In a specific embodiment, when the line operation mode has not changed, the normal flow transfer control process includes: the first step, the control and protection device can calculate the actual flow on both sides of the closing device by receiving the two incoming line voltages PT1 / 2 and the two incoming line currents CT1 / 2. The second step is to determine whether the control and protection device receives the first flow transfer instruction issued by the dispatching main station or the monitoring background. If the flow transfer instruction is not received, the current cycle is terminated directly. If the flow transfer instruction is received, the next flow transfer process is entered; the third step is for the controller to determine whether the difference between the real-time power and the flow transfer instruction value is within the error range of 500kW? If it is within the error range, the current cycle is terminated directly. If it is not within the error range, the next step is entered; the fourth step is for the controller to calculate the corresponding compensation voltage instruction value according to the first flow transfer instruction, and send the compensation voltage instruction value to the voltage regulating mechanism. The fifth step is for the voltage regulating mechanism to execute the instruction after receiving the compensation voltage instruction value to synthesize the compensation voltage. It should be pointed out that the voltage regulating mechanism may need to make several consecutive adjustments to reach the compensation voltage corresponding to the flow transfer instruction value. In the sixth step, the controller records the transfer power flow step length ΔP1 corresponding to each adjustment of the synthetic voltage, and repeats the third to sixth steps until the difference between the real-time power and the power flow transfer command value is within the error range of 500kW, and the power flow transfer is completed.

[0057] When the line operation mode changes, the adaptive algorithm control process is executed: the first step is that the control and protection device can calculate the actual flow on both sides of the closing device by receiving the two incoming line voltages PT1 / 2 and the two incoming line currents CT1 / 2. The second step is to determine whether the control and protection device receives the second flow transfer instruction issued by the dispatching master station or the monitoring background. If the flow transfer instruction is not received, the current cycle is terminated directly. If the flow transfer instruction is received, the next flow transfer process is entered; the third step is that the controller determines whether the difference between the real-time power and the flow transfer instruction value is within the error range of 500kW? If it is within the error range, the current cycle is terminated directly. If it is not within the error range, the next step is entered; the fourth step is that the controller calculates the corresponding compensation voltage instruction value according to the second flow transfer instruction, and sends the compensation voltage instruction value to the voltage regulating mechanism. The fifth step is that after the voltage regulating mechanism receives the compensation voltage instruction value, it executes the instruction and synthesizes the compensation voltage. It should be pointed out that the voltage regulating mechanism may need to make several consecutive adjustments to reach the compensation voltage corresponding to the flow transfer instruction value. In the sixth step, the controller records the transfer power flow step length ΔP2 corresponding to each adjustment of the synthetic voltage. In the seventh step, the controller compares the current transfer power flow step length ΔP2 with the ΔP1 recorded during the last power flow transfer. If the difference between the two is less than 300kW, it is considered that the line operation mode has not changed and the power flow transfer process continues; if the difference between the two is greater than 300kW, it is determined that the line operation mode has changed and it is necessary to adjust the gear position of the on-load tap changer, thereby modifying the transformation ratio of the series transformer. In the eighth step, according to the difference between ΔP2 and ΔP1, calculate the gear position that the on-load voltage regulator on the secondary side of the corresponding series transformer needs to be adjusted to. If ΔP2-ΔP1>300kW, it means that the line has become shorter, and the on-load voltage regulator should be lowered by one gear to improve the adjustment accuracy. Suppose it was originally in gear 2, it should be adjusted to gear 1 this time; if ΔP2-ΔP1<-300kW, it means that the line has become longer, and the on-load voltage regulator needs to be raised to change the maximum adjustment range of the device. Suppose it was originally in gear 2, it should be adjusted to gear 3 this time; In the ninth step, the controller records the step length ΔP1 of this transfer flow, and repeats steps 3 to 8 until the difference between the real-time power and the flow transfer command value is within the error range of 500kW, and this adaptive algorithm ends.

[0058] Example 2

[0059] The present invention also provides a control method for a composite voltage regulator, which comprises: controlling the conduction state of the voltage regulating mechanism and / or the connection relationship between the on-load voltage regulating switch and each gear on the secondary side of the series transformer by a control protection device based on the real-time power at the incoming line of the composite voltage regulator and the received power flow transfer instruction.

[0060] Preferably, when the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction exceeds 500kW, the conduction state of each tap of the secondary winding on the secondary side of the connected transformer is adjusted by sending a pulse signal to the voltage regulating mechanism to control the on and off of the thyristors in each power valve by the user, until the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction does not exceed 500kW.

[0061] Furthermore, the transfer power flow step length corresponding to the compensation voltage output by the voltage regulating mechanism is recorded each time the conduction state of the voltage regulating mechanism is adjusted; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment exceeds 300kW, the on-load voltage regulating switch is controlled to lower one gear; when the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment does not exceed -300kW, the on-load voltage regulating switch is controlled to increase one gear.

[0062] Example 3

[0063] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a control method of a composite voltage regulating device in the above embodiment.

[0064] Example 4

[0065] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage device (Memory), which is a memory device in a computer device for storing programs and data. It can be understood that the computer-readable storage device here can include both the built-in storage medium in the computer device and the extended storage medium supported by the computer device. The computer-readable storage device provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage device here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage device to implement the steps of a control method of a composite voltage regulating device in the above embodiment.

[0066] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0067] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0068] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0069] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A composite voltage regulator, characterized in that: The device comprises: a first incoming line connection port, a second incoming line connection port, a parallel transformer, a voltage regulating mechanism, a series transformer, an on-load voltage regulating switch and a control and protection device; The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of two substations of the distribution network; The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, the three phases of the tail end of the primary side of the parallel transformer are connected to form a neutral point, each phase of the secondary side of the parallel transformer includes multiple secondary windings, each secondary winding includes three taps, and each tap is connected to the secondary side of the series transformer in turn through a voltage regulating mechanism and an on-load tap-changing switch, and the two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer; The control and protection device is used to control the conduction state of the voltage regulating mechanism and / or the connection relationship between the on-load voltage regulating switch and each gear position of the secondary side of the series transformer based on the real-time power at the incoming line of the composite voltage regulating device and the received power flow transfer instruction.

2. The device according to claim 1, characterized in that The first incoming line connection port and the second incoming line connection port are respectively connected to a first voltage collection device and a second voltage collection device for collecting the voltage value required for the control protection device to calculate the real-time power at the incoming line of the composite voltage regulation device; the first incoming line connection port and the second incoming line connection port are respectively connected to a first current collection device and a second current collection device for collecting the current value required for the control protection device to calculate the real-time power at the incoming line of the composite voltage regulation device.

3. The device according to claim 2, characterized in that A first switch is connected between the first incoming line connection port and the first current collection device, and a second switch is connected between the second incoming line connection port and the first current collection device.

4. The device according to claim 1, characterized in that The voltage regulating mechanism includes a power valve corresponding to the secondary winding on the secondary side of the parallel transformer, the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding, and the outputs of the three power valves are connected in series to form a power valve group. The head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to an on-load voltage regulating switch.

5. The device according to claim 4, characterized in that The power valve comprises three pairs of thyristors connected in parallel.

6. The device according to claim 1, characterized in that The secondary side of the series transformer includes a plurality of taps, each of which corresponds to a tap of the on-load tap changer.

7. The device according to claim 6, characterized in that The secondary side of the series transformer includes four taps, and the corresponding transformation ratios are 0.5:1, 1:1, 1.5:1 and 2:1 respectively.

8. The device according to claim 1, characterized in that Each phase of the secondary side of the parallel transformer includes three secondary windings.

9. The device according to claim 5, characterized in that The control and protection device is specifically used for: when the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction exceeds 500kW, by sending a pulse signal for controlling the on and off of the thyristors in each power valve to the voltage regulating mechanism, until the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction does not exceed 500kW.

10. The device according to claim 1, characterized in that The control and protection device is specifically used for: recording the transfer power flow step length corresponding to the compensation voltage output by the voltage regulating mechanism after each adjustment of the conduction state of the voltage regulating mechanism; when the difference between the transfer power flow step length corresponding to the current adjustment and the transfer power flow step length corresponding to the previous adjustment exceeds 300kW, controlling the on-load voltage regulating switch to lower one gear; when the difference between the transfer power flow step length corresponding to the current adjustment and the transfer power flow step length corresponding to the previous adjustment does not exceed -300kW, controlling the on-load voltage regulating switch to increase one gear.

11. A control method based on the composite voltage regulator according to any one of claims 1 to 10, characterized in that: The method comprises: controlling the conduction state of the voltage regulating mechanism and / or the connection relationship between the on-load voltage regulating switch and each gear of the secondary side of the series transformer by a control protection device based on the real-time power at the incoming line of the composite voltage regulating device and the received power flow transfer instruction.

12. The method according to claim 11, characterized in that When the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction exceeds 500kW, the conduction state of each tap of the secondary winding on the secondary side of the connected transformer is adjusted by sending a pulse signal to the voltage regulating mechanism to control the on and off of the thyristors in each power valve by the user, until the difference between the real-time power at the incoming line of the composite voltage regulating device and the power flow corresponding to the received power flow transfer instruction does not exceed 500kW.

13. The method according to claim 12, characterized in that The transfer power flow step length corresponding to the compensation voltage output by the voltage regulating mechanism is recorded each time after the conduction state of the voltage regulating mechanism is adjusted. When the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment exceeds 300kW, the on-load voltage regulating switch is controlled to lower one gear. When the difference between the transfer power flow step length corresponding to the current adjustment number and the transfer power flow step length corresponding to the previous adjustment does not exceed -300kW, the on-load voltage regulating switch is controlled to increase one gear.

14. A computer device, characterized in that: include: one or more processors; The processor is configured to execute one or more programs; When the one or more programs are executed by the one or more processors, the control method of the composite voltage regulation device according to any one of claims 11 to 13 is implemented.

15. A computer readable storage device, characterized in that: A computer program is stored thereon, and when the computer program is executed, the control method of the composite voltage regulating device according to any one of claims 11 to 13 is implemented.

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