CN114530893A - Modular power electronic type amorphous alloy on-load arc-free capacitance regulating system and method - Google Patents

Modular power electronic type amorphous alloy on-load arc-free capacitance regulating system and method Download PDF

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CN114530893A
CN114530893A CN202210176637.0A CN202210176637A CN114530893A CN 114530893 A CN114530893 A CN 114530893A CN 202210176637 A CN202210176637 A CN 202210176637A CN 114530893 A CN114530893 A CN 114530893A
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voltage
bidirectional thyristor
thyristor
inductor
capacity
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文启东
梁得亮
张立石
杨澍州
李佳
刘桦
王宇珩
柳轶彬
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Xian Jiaotong University
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Xian Jiaotong University
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    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/466—Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
    • 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
    • H01F27/24—Magnetic cores
    • 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
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • 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
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H01F27/341—Preventing or reducing no-load losses or reactive currents
    • 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
    • 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
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Electrical Variables (AREA)

Abstract

The invention discloses a modular power electronic type amorphous alloy on-load arc-free capacitance regulating system and method. The capacity regulating transformer comprises a boosting capacity regulating transformer body, a low-voltage primary side bidirectional thyristor valve group and a high-voltage secondary side bidirectional thyristor valve group. And the integrated main control system comprises a driving circuit, a signal conditioning circuit, a main control circuit, a voltage and current detection circuit, a switching power supply and a 5G communication module. The transformer can be widely applied to the output end of the photovoltaic power generation inverter as a boosting transformer, the power electronic type capacity regulating transformer of the system can solve the redundant loss of unmatched transformer capacity caused by photovoltaic power generation volatility, the transient process of arc-free capacity regulation can be quickly realized, the rapidity of capacity regulation is ensured, and the quality of power supply is also ensured. Meanwhile, the amorphous alloy is used as the iron core material of the transformer, so that the no-load loss of the transformer can be further reduced.

Description

Modular power electronic type amorphous alloy on-load arc-free capacitance regulating system and method
Technical Field
The invention belongs to the field of transformers, and particularly relates to a modular power electronic type amorphous alloy on-load arc-free capacitance regulating system and method.
Background
With the progress of the technological level and the rapid development of economy, the utilization rate of human energy is higher and higher, and among various energy sources, electric energy is the most important energy source in the production and the life of people, so that the related electric energy conservation and the adjustment of the electric energy quality are concerned by various fields. The loss of electric energy also affects the safety and economy of the power grid.
The photovoltaic power generation type new energy which is the most commonly used new energy at present is widely applied to various micro-grid systems at all levels as distributed energy. However, the uncertainty of illumination causes frequent fluctuation of the photovoltaic power generation amount, so that the step-up transformer connected to the output side of the photovoltaic inverter is difficult to operate in a rated state for a long time. This results in large no-load losses.
Aiming at the problem of no-load loss of a photovoltaic boosting transformer caused by uncertainty of power generation, the existing solution mainly starts with the iron core material of the transformer, selects an iron core material with lower loss, such as an amorphous alloy material, and can reduce the no-load loss by 60 percent compared with the traditional silicon steel material under the same capacity grade.
However, the energy-saving angle of the existing technologies is too single, and the traditional amorphous alloy transformer cannot realize the capacity adaptive adjustment. The existing capacity regulating transformer is designed only for a step-down transformer of a power distribution network, and the non-arc and quick capacity regulation is difficult to realize. Therefore, it is necessary to design a power electronic amorphous alloy capacity-regulating transformer suitable for a photovoltaic step-up transformer.
Disclosure of Invention
The invention discloses a modular power electronic type amorphous alloy on-load arc-free capacity regulating system and method, which aim to solve the problem that a boosting transformer at a power generation inversion end of a traditional photovoltaic power generation system cannot realize capacity regulation and overcome the defect that the capacity cannot be quickly switched without an arc by the traditional capacity regulating transformer.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
a modular power electronic type amorphous alloy on-load arc-free capacitance regulating system comprises a transformer body, wherein one side of the transformer body is a low-voltage input side, and the other side of the transformer body is a high-voltage output side;
the low-voltage input side is connected with an inverter, and the inverter is connected with a photovoltaic power supply; the high-voltage output side is connected with a medium-voltage transmission network;
the low-voltage input side comprises three low-voltage-end input-side thyristor valve groups which are connected in parallel, each low-voltage-end input-side thyristor valve group comprises a second inductor and a third inductor which are connected in parallel, the first end of the second inductor and the first end of the third inductor are simultaneously connected with the output end of the inverter, the second end of the second inductor and the second end of the third inductor are simultaneously connected with the first end of the first inductor, and the second ends of the first inductors in the three input-side thyristor valve groups are connected to the transformer body together; a bidirectional thyristor S is arranged between the first end of the second inductor and the first end of the third inductora5、Sb5Or Sc5A bidirectional thyristor S is arranged between the second end of the second inductor and the second end of the third inductora4、Sb4Or Sc4A bidirectional thyristor S is arranged between the first end of the second inductor and the second end of the third inductora3、Sb3Or Sc3；
The high-voltage output side comprises a high-voltage end output side thyristor valve group (9), the high-voltage end output side thyristor valve group (9) comprises three fourth inductors which are sequentially connected end to end, the three fourth inductors form a triangle, and a bidirectional thyristor S is arranged at the first end of each fourth inductora1、Sb1Or Sc1(ii) a Each bidirectional thyristor Sa1、Sb1Or Sc1A branch is arranged between the fourth inductor and the corresponding inductor, and a bidirectional thyristor S is arranged on the brancha2、Sb2Or Sc2Three-branch bidirectional thyristor Sa2、Sb2And Sc2Is connected with the second end of the first end;
and the output end of the inverter, the input end of the medium-voltage transmission network, the low-voltage end input side thyristor valve group and the high-voltage end output side thyristor valve group are connected to the controller together.
The invention is further improved in that:
preferably, the transformer body comprises a magnetic core and a winding wound on the magnetic core;
the magnetic core is made of amorphous alloy.
Preferably, each low-voltage-end input-side thyristor valve group is provided with an input driving port and an input detection port.
Preferably, the low-voltage input side is connected to the inverter through an input voltage port.
Preferably, the high-voltage end output side thyristor valve group is provided with an output driving port and an output detection port.
Preferably, the high voltage side output side is connected to the medium voltage transmission network via an output voltage port.
Preferably, the controller comprises a main control board, and the main control board is simultaneously connected with a driving circuit board, an electric energy management control board, a pulse generation circuit board and a 5G communication module.
Preferably, the driving circuit board is used for driving each bidirectional thyristor to be switched on and off; the electric energy management control board is used for collecting voltage and current signals from the output end of the inverter and collecting current signals from the input end of the medium-voltage transmission network; the pulse generation circuit board is used for converting the level signal of the main control board into a pulse signal and inputting the pulse signal to the electric energy management control board; and the 5G communication module is used for communication between the main control board and the upper computer.
A capacity regulating method of a modular power electronic type amorphous alloy on-load arc-free capacity regulating system is characterized in that a capacity regulating point of the capacity regulating system is calculated, and when the output power of one side of an inverter is smaller than the capacity regulating point, a low-voltage end input side thyristor valve group and a high-voltage end output side thyristor valve group are regulated to reduce the capacity regulating point of the capacity regulating system;
and when the output power of one side of the inverter is greater than the capacitance adjusting point, judging whether the input power of the medium-voltage power transmission network is greater than the capacitance adjusting point, if so, increasing the capacitance adjusting point of the capacitance adjusting system, and if less, decreasing the capacitance adjusting point of the capacitance adjusting system.
Preferably, the process of reducing the capacity regulating point of the capacity regulating system comprises:
for the high-voltage output side, when flowing through the bidirectional thyristor Sa1When the current of the trigger bidirectional thyristor is zeroa2(ii) a When flowing through the bidirectional thyristor Sb1When the current of the trigger bidirectional thyristor is zerob2(ii) a When flowing through the bidirectional thyristor Sc1When the current of the trigger bidirectional thyristor is zeroc2；
For the low-voltage input side, when the current flows through the bidirectional thyristor Sa5And Sa4Trigger the bidirectional thyristor S when the currents are all 0a3(ii) a When flowing through the bidirectional thyristor Sb5And Sb4Trigger the bidirectional thyristor S when the currents are all 0b3(ii) a When flowing through the bidirectional thyristor Sc5And Sc4Trigger the bidirectional thyristor S when the currents are all 0c3；
The process of improving the capacity regulating point of the capacity regulating system comprises the following steps:
for the high-voltage output side, when flowing through the bidirectional thyristor Sa2Trigger the bidirectional thyristor S when the current ofa1(ii) a When flowing in both directionsThyristor Sb2When the current of the trigger bidirectional thyristor is zerob1(ii) a When flowing through the thyristor Sc2Is zero, triggers the thyristor Sc1；
For the low voltage input side, when flowing through the bidirectional thyristor Sa3When the current of (1) is 0, the bidirectional thyristor S is triggereda5And Sa4(ii) a When flowing through the bidirectional thyristor Sb3When the current of (1) is 0, the bidirectional thyristor S is triggeredb5And Sb4(ii) a When flowing through the bidirectional thyristor Sc3When the current of (1) is 0, the bidirectional thyristor S is triggeredc5And Sc4。
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a modular power electronic type amorphous alloy on-load arc-free capacitance regulating system. The capacity regulating transformer comprises a boosting capacity regulating transformer body, a low-voltage primary side bidirectional thyristor valve group and a high-voltage secondary side bidirectional thyristor valve group. And the integrated main control system comprises a driving circuit, a signal conditioning circuit, a main control circuit, a voltage and current detection circuit, a switching power supply and a 5G communication module. The transformer can be widely applied to the output end of the photovoltaic power generation inverter as a boosting transformer, the power electronic type capacity regulating transformer of the system can solve the redundant loss of unmatched transformer capacity caused by photovoltaic power generation volatility, the transient process of arc-free capacity regulation can be quickly realized, the rapidity of capacity regulation is ensured, and the quality of power supply is also ensured. Meanwhile, the amorphous alloy is used as the iron core material of the transformer, so that the no-load loss of the transformer can be further reduced.
The invention also discloses a modular power electronic type amorphous alloy on-load arc-free capacity regulating method, aiming at the problem of fluctuation of photovoltaic power generation, a transformer can detect the power generated by a power supply side and the power generated by a load side, and then a controller can rapidly, arc-free and smoothly switch between the two capacities according to an internally set control algorithm and strategy so as to reduce the loss of the transformer. Meanwhile, the introduction of the amorphous alloy material can furthest play the aims of energy conservation and loss reduction of the capacity-regulating transformer.
Drawings
Fig. 1 is a schematic structural diagram of a capacity regulating transformer for power electronic amorphous alloy photovoltaic of the present invention.
Fig. 2 is a schematic diagram of a capacitance-regulating transformer for power electronic amorphous alloy photovoltaic according to the present invention.
FIG. 3 is a circuit diagram of the power electronic type amorphous alloy photovoltaic capacity-regulating transformer of the present invention.
FIG. 4 is a flow chart of the capacitance-adjusting strategy for power electronic amorphous alloy photovoltaic of the present invention.
Wherein, 1-a controller; 2-low-voltage end input side thyristor valve group; 3-input drive port; 4-input detection port; 5-input voltage port; 6-output voltage port; 7-output drive port; 8-an output detection port; 9-a thyristor valve group at the output side of the high-voltage end; 10-a magnetic core; 11-base.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
the invention discloses a modular power electronic type amorphous alloy on-load arc-free capacitance regulating system, which comprises a boosting and capacitance regulating transformer body, a power electronic switch valve group, a controller 1 and a current sensor module, and is shown in figure 1.
The controller 1 is composed of a main control board (which can be a series of mainstream controllers in the market such as a DSP controller and an ST), a bidirectional thyristor driving circuit board, an electric energy management control board, a pulse generation circuit board and a 5G communication module. The bidirectional thyristor drive circuit, the electric energy management control panel, the pulse generation circuit board and the 5G communication module are all connected with the main control panel. The main control board outputs 15 paths of control signals, a bidirectional thyristor is correspondingly connected with a bidirectional thyristor drive circuit, each path of control signal is input to a bidirectional thyristor drive circuit board, and the output signal of each drive circuit board is input to a bidirectional thyristor for controlling the bidirectional thyristor to be switched on and switched off. The electric energy management control panel is used for detecting current signals of a high-voltage output side of the system, wherein the voltage signals of the high-voltage output side are fixed values and are related to the voltage level of a power grid, and voltage and current signals of a low-voltage input side, and then active energy and reactive energy are calculated and transmitted to the main control panel for control decision. The pulse generation circuit board is used for converting level signals of the main control board into pulse signals to be input to the bidirectional thyristor driving circuit board, voltage sensing for testing voltage of a low-voltage input side is integrated on the electric energy management control board, voltage value sampling is carried out on voltage values collected through the electric energy management control board, and finally the 5G communication module is used for communicating the controller with an upper computer located on a user side, so that centralized scheduling operation is facilitated.
The topological structure of the relation between the transformer body and the power electronic switch valve set is shown in figure 1, and the capacity regulating system designed by the invention is mainly used for connecting a photovoltaic inverter and a medium-voltage transmission network. Compared with the traditional capacity regulating transformer, the output end of the capacity regulating system is connected to the medium-voltage transmission network at the medium-high voltage of 35KV, and the input end of the capacity regulating system is the medium-low voltage output by the photovoltaic inverter. Therefore, in order to switch the capacity adjustment strategy, it is necessary to perform determination and perform corresponding capacity switching by comprehensively considering the power on the power supply side and the power on the load side.
Referring to fig. 1, a thyristor valve block of a power electronic switch is designed to have a high-voltage side and a low-voltage side, and the high-voltage side and the low-voltage side are respectively arranged on two sides of a transformer body; the low-voltage side is an input side, the low-voltage side is defined as a low-voltage input side, a serial-parallel topological structure is adopted, 3 discrete valve groups are designed, each valve group is provided with three bidirectional thyristors, and 9 bidirectional thyristors are used as capacitance regulating switches. The high-voltage side is an output side and is defined as the high-voltage output side, a Y-shaped and triangular interchange topological structure is adopted, and six thyristors are adopted as an independent valve group and are used as a capacitance regulating switch. In addition, each bidirectional thyristor is provided with a current sensor, and the main control board is used for detecting the current magnitude so as to select a control strategy.
Referring to fig. 1, fig. 2 and fig. 3, there are shown one possible schematic structural diagrams of the capacitance-regulating transformer for power electronic amorphous alloy photovoltaic according to the present invention, but the present invention is not limited to such a schematic structural diagram.
Referring to fig. 2, the transformer of the present invention is provided with a base 11, the base 11 is provided with a controller 1, and the controller 1 is provided with 1 a main control board, a triac driving circuit board, an electric energy management control board, a pulse generation circuit board and a 5G communication module integrated with the capacity regulating transformer. The controller 1 is provided with a display screen and a plurality of keys, the back of the controller 1 is provided with 44 wiring ports, wherein 15 wiring ports are output wiring ports, the output wiring ports are connected with the bidirectional thyristor driving circuit board in the controller 1, and each output wiring port is connected with one bidirectional thyristor and used for outputting driving signals of the bidirectional thyristor; the other 15 wiring ports are input wiring ports, the input wiring ports are connected with the electric energy management control panel in the controller 1, and each wiring port outside the controller 1 is connected with a bidirectional thyristor and used for inputting acquired current detection signals of the 15 paths of bidirectional thyristors; the remaining 12 wiring ports are used for detecting three-phase voltage and three-phase current on the low-voltage side and the high-voltage side, and in addition, 2 wiring ports are used for introducing single-phase alternating-current voltage from an inverter on the low-voltage side and performing auxiliary power supply on the whole controller through an internal switching power supply module.
The base 11 is provided with a magnetic core 10 and a winding wound thereon. The material of the magnetic core 10 used by the transformer body is amorphous alloy, and the no-load loss of the amorphous alloy capacity-regulating transformer under the same capacity can be reduced by about 60 percent compared with the no-load loss of the transformer made of the traditional silicon steel material.
Referring to fig. 2, three low-voltage-side input-side thyristor valve blocks 2 are arranged on one side of a magnetic core 10, only an external heat sink structure of the valve blocks is shown in fig. 2, and 3 triacs with high withstand voltage and 3 current sensors are integrated in each low-voltage-side input-side thyristor valve block 2. More specifically, referring to fig. 1, an input drive port 3 for driving the triac and an output detection port 4 for detecting the current and voltage of the triac are provided at an upper portion of each low-voltage-side input-side thyristor valve block 2. The three low-voltage end input side thyristor valve groups 2 are connected in parallel, the low-voltage end input side thyristor valve group 2 of each phase is connected with a phase winding, and two parallel inductors, namely a second inductor and a third inductor, are arranged in the direction from the low-voltage input side to the magnetic core 10 of the low-voltage end input side thyristor valve group 2 of each phaseThe inductor comprises two inductors connected in parallel, wherein the second ends of the two inductors are connected to the first inductor together, the second end of the first inductor is connected to a phase winding, a bidirectional thyristor is arranged between the first end of the second inductor and the first end of the third inductor, a bidirectional thyristor is arranged between the first end of the second inductor and the second end of the third inductor, and a bidirectional thyristor is arranged between the second end of the second inductor and the second end of the third inductor. Taking phase A as an example, the first inductance is W21The second inductance is W22The third inductance is W23，W22And W23Parallel connection, W22Second end of and W23Is common to W21Is connected to a first end of, W22Second end of and W23Between the second ends is provided with a switch Sa5，W22Second end of and W23Between the second ends is provided with a switch Sa4，W22First end of (A) and W23Between the second ends is provided with a switch Sa3，W22First end of (A) and W23Are connected in common to the inverter output a. The connection mode of the B phase and the C phase is the same as that of the A phase, and the description is omitted here. Each phase thyristor valve group 2 is connected with one of the output voltages of the inverter through an input voltage port 5.
Referring to fig. 3, the output side of the magnetic core 10 is provided with a high-voltage end output side thyristor valve group 9. The tail end of the high-voltage end output side thyristor valve group 9 is provided with an output voltage port 6 of the secondary side output voltage, and the output voltage port 6 of the secondary side output voltage is connected with a voltage transmission network. Each phase of the high-voltage output side thyristor valve group 9 is connected with a corresponding winding, and control is shown in fig. 3, which only shows the structure of the heat sink outside the high-voltage output side thyristor valve group 9, and 6 triacs and 6 current sensors are integrated inside the high-voltage output side thyristor valve group 9. The upper part of the high-voltage end output side thyristor valve group 9 is provided with an output driving port 7 for driving a bidirectional thyristor and an output detection port 9 for detecting thyristor current, the output driving port 7 is connected with a bidirectional thyristor driving circuit board of the controller 1 through an output wiring port, and the output detection port 9 is connected with an electric energy management control panel in the controller 1 through an input wiring port. High-voltage end output side crystalThe thyristor valve 9 is connected by three fourth inductors in a triangular form, the three fourth inductors are connected end to end, the first end of each first inductor is provided with a bidirectional thyristor which is S respectivelya1、Sb1And Sc1；Sa1、Sb1And Sc1The first end of the transformer is connected with the corresponding inductor, and the second end of the transformer is connected with the medium-voltage transmission network; sa1、Sb1And Sc1Is provided with a branch, on which a bidirectional thyristor is arranged, respectively Sa2、Sb2And Sc2；Sa2、Sb2And Sc2First end of (A) and Sa1、Sb1And Sc1Is connected to a first end of, Sa2、Sb2And Sc2Is connected to a point, forming a Y-shaped topology.
Fig. 1 shows the connection mode and the control mode of the transformer in the whole photovoltaic power system. Firstly, the direct-current voltage output by the photovoltaic cell panel is output as three-phase alternating-current voltage through the inverter, the three-phase alternating-current voltage is connected with the low-voltage side ABC of the capacity regulating transformer, and the high-voltage side of the transformer outputs 35KV high voltage to be merged into a power grid. In the structure of the capacitance regulating, because the capacitance regulating transformer is a boosting transformer, compared with the traditional capacitance regulating transformer, the triangular Y-shaped structure of the capacitance regulating transformer is positioned on the secondary side of the transformer, and the series-parallel structure is positioned on the primary side of the capacitance regulating transformer, which is due to the consideration of the inductance current withstanding value of the transformer and the voltage withstanding value of the bidirectional thyristor switch. Due to the particularity of the capacity regulating transformer for photovoltaic, compared with the capacity regulating transformer on the common power distribution side, the capacity regulating transformer needs to detect the voltage current on the input side of the photovoltaic inverter and the current on the input network side at the same time. Once the power of a certain side is greater than the power corresponding to the capacitance adjusting point, the capacitance adjusting signal can be started, and at the moment, the controller can send out a corresponding trigger driving signal.
Compared with the traditional capacity regulating transformer, the control strategy of the capacity regulating transformer provided by the invention has more signals needing to be detected, and the control strategies of the corresponding transformers are different. The uncertainty of the power generated by the photovoltaic power supply can be caused by the uncertainty of the conditions in the power generation process of the photovoltaic power supply, so that the generated power has randomness. The traditional capacity regulating transformer solves the problem that capacity is regulated according to the power of a load side, because a power grid can be regarded as a power source with infinite capacity, but the capacity regulating transformer applied to a photovoltaic power supply is different, so that not only the power of the load side but also the power measured by the power supply need to be considered. The specific capacity-adjusting logic flow diagram is shown in fig. 4:
the specific capacity regulating logic flow chart is shown in fig. 4, and the capacity regulating point of the capacity regulating transformer at the current moment can be obtained according to the algorithm of the capacity regulating calculation. Once the output power of the power generation side is less than the capacity adjustment point, the capacity adjustment switch needs to be controlled to adjust the capacity to a small capacity state. If the power of the power generation side is larger than the capacity regulating point, the power of the load side needs to be judged, if the power of the load side is also larger than the capacity regulating point, the capacity regulating system needs to be regulated to be in a large capacity state, and once the power of the load side is smaller than the capacity regulating point, the capacity of the capacity regulating system needs to be regulated to be in a small capacity state.
The capacity regulating transformer of the power electronic switch aims at realizing the capacity regulating process of arc-free on-load through some control strategies and has quick action speed. The specific switching strategy is to take the secondary side of the process of large capacity regulation to small capacity as an example, because the switch S is switched at the time of large capacitya1、Sb1、Sc1Opening, Sa2、Sb2、Sc2And (5) closing. So that the switch S needs to be closed when the capacity is adjusted to be smalla1、Sb1、Sc1Turn on switch Sa2、Sb2、Sc2. If turned off, cancel Sa1、Sb1、Sc1When the trigger signal of the bidirectional thyristor is generated, the trigger signal is applied to the thyristor S by the vertical horsea2、Sb2、Sc2The six thyristors are closed at the same time, which may cause the power supply to be short-circuited to damage the equipment. Therefore, the control strategy proposed in this embodiment is: detecting flow through thyristor Sa1、Sb1、Sc1When a current flows through the thyristor Sa1Is zero, triggers the thyristor Sa2(ii) a When flowing through the thyristor Sb1Is zero, triggers the thyristor Sb2(ii) a When flowing through the thyristor Sc1Is zero, triggers the thyristor Sc2(ii) a Therefore, the device can be prevented from being damaged by power supply short circuit, and meanwhile, the capacity adjustment is carried out without power failure, so that the power supply quality is ensured. The process of adjusting the A-phase large capacity to the small capacity is taken as an example for the thyristor on the primary side: first detecting the flow through Sa5And Sa4The current of the thyristor of (1) is triggered after waiting for the current flowing through the two bidirectional thyristors to be both 0a3A thyristor; for the thyristor on the primary side, the process of adjusting the large capacity of the phase B to the small capacity is taken as an example: first detecting the flow through Sb5And Sb4The current of the thyristor of (1) is triggered after waiting for the current flowing through the two bidirectional thyristors to be both 0b3A thyristor; the process of adjusting the large capacity of the C phase to the small capacity is taken as an example for the thyristor at the primary side: first detecting the flow through Sc5And Sc4The current of the thyristor of (1) is triggered after waiting for the current flowing through the two bidirectional thyristors to be both 0c3A thyristor; therefore, the next group of thyristors can be triggered immediately after the previous group of thyristors are effectively turned off, seamless switching between two capacities is realized, and the accident of power supply short circuit cannot occur.
Taking the secondary side of the process of adjusting the small capacity to the large capacity as an example, the control strategy proposed in this embodiment is: detecting flow through thyristor Sa2、Sb2、Sc2When a current flows through the thyristor Sa2Is zero, triggers the thyristor Sa1(ii) a When flowing through the thyristor Sb2Is zero, triggers the thyristor Sb1(ii) a When flowing through the thyristor Sc2Is zero, triggers the thyristor Sc1(ii) a Therefore, the device can be prevented from being damaged by power supply short circuit, and meanwhile, the capacity adjustment is carried out without power failure, so that the power supply quality is ensured.
The process of regulating the A-phase small capacity to the large capacity is taken as an example for the primary side thyristor: first detecting the flow through Sa3The current of the thyristor waiting to flow through the bidirectionalThe thyristor is triggered S after the current is 0a5And Sa4A thyristor. The process of regulating the small capacity of the B phase to the large capacity is taken as an example for the thyristor at the primary side: first detecting the flow through Sb3The current of the thyristor of (1) is triggered after waiting for the current flowing through the bidirectional thyristor to be 0b5And Sb4A thyristor. The process of adjusting the C-phase small capacity to the large capacity is taken as an example for the primary side thyristor: first detecting the flow through Sc3The current of the thyristor of (1) is triggered after waiting for the current flowing through the bidirectional thyristor to be 0c5And Sc4A thyristor.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. A modular power electronic type amorphous alloy on-load arc-free capacitance regulating system is characterized by comprising a transformer body, wherein one side of the transformer body is a low-voltage input side, and the other side of the transformer body is a high-voltage output side;
the low-voltage input side is connected with an inverter, and the inverter is connected with a photovoltaic power supply; the high-voltage output side is connected with a medium-voltage transmission network;
the low-voltage input side comprises three low-voltage-end input-side thyristor valve groups (2) which are connected in parallel, each low-voltage-end input-side thyristor valve group (2) comprises a second inductor and a third inductor which are connected in parallel, the first end of the second inductor and the first end of the third inductor are connected with the output end of the inverter at the same time, the second end of the second inductor and the second end of the third inductor are connected with the first end of the first inductor at the same time, and the second ends of the first inductors in the three input-side thyristor valve groups (2) are connected to the transformer body together; a bidirectional thyristor S is arranged between the first end of the second inductor and the first end of the third inductora5、Sb5Or Sc5A bidirectional thyristor S is arranged between the second end of the second inductor and the second end of the third inductora4、Sb4Or Sc4First terminal of second inductorA bidirectional thyristor S is arranged between the first inductor and the second inductora3、Sb3Or Sc3；
The high-voltage output side comprises a high-voltage end output side thyristor valve group (9), the high-voltage end output side thyristor valve group (9) comprises three fourth inductors which are sequentially connected end to end, the three fourth inductors form a triangle, and a bidirectional thyristor S is arranged at the first end of each fourth inductora1、Sb1Or Sc1(ii) a Each bidirectional thyristor Sa1、Sb1Or Sc1A branch is arranged between the fourth inductor and the corresponding inductor, and a bidirectional thyristor S is arranged on the brancha2、Sb2Or Sc2Three-branch bidirectional thyristor Sa2、Sb2And Sc2Is connected with the second end of the first end;
the output end of the inverter, the input end of the medium-voltage transmission network, the low-voltage end input side thyristor valve group (2) and the high-voltage end output side thyristor valve group (9) are connected to the controller (1) together.
2. The modular power electronic type amorphous alloy on-load arc-free capacitance regulating system as claimed in claim 1, wherein the transformer body comprises a magnetic core (10) and a winding wound on the magnetic core (10);
the magnetic core (10) is made of amorphous alloy.
3. A modular power electronic type amorphous alloy on-load arc-free capacitance regulating system as claimed in claim 1, wherein each low-voltage end input side thyristor valve group (2) is provided with an input drive port (3) and an input detection port (4).
4. The modular power electronic type amorphous alloy on-load arc-free capacitance regulating system as claimed in claim 1, wherein the low voltage end input side is connected with an inverter through an input voltage port (5).
5. The modular power electronic type amorphous alloy on-load arc-free capacitance regulating system as claimed in claim 1, wherein an output driving port (7) and an output detection port (8) are arranged on the high-voltage end output side thyristor valve group (9).
6. The modular power electronic type amorphous alloy on-load arc-free capacitance regulating system according to claim 1, characterized in that the high-voltage end output side is connected with the medium-voltage transmission network through an output voltage port (6).
7. The modular power electronic type amorphous alloy on-load arc-free capacitance regulating system as claimed in claim 1, wherein the controller (1) comprises a main control board, and the main control board is simultaneously connected with a driving circuit board, an electric energy management control board, a pulse generation circuit board and a 5G communication module.
8. The modular power electronic type amorphous alloy on-load arc-free capacitance regulating system as claimed in claim 7, wherein the driving circuit board is used for driving each bidirectional thyristor to be switched on and off; the electric energy management control board is used for collecting voltage and current signals from the output end of the inverter and collecting current signals from the input end of the medium-voltage transmission network; the pulse generation circuit board is used for converting the level signal of the main control board into a pulse signal and inputting the pulse signal to the electric energy management control board; and the 5G communication module is used for communication between the main control board and the upper computer.
9. A capacity regulating method of a modular power electronic type amorphous alloy on-load arc-free capacity regulating system is characterized in that a capacity regulating point of the capacity regulating system is calculated, and when the output power of one side of an inverter is smaller than the capacity regulating point, a low-voltage-end input side thyristor valve group (2) and a high-voltage-end output side thyristor valve group (9) are regulated to reduce the capacity regulating point of the capacity regulating system;
and when the output power of one side of the inverter is greater than the capacitance adjusting point, judging whether the input power of the medium-voltage power transmission network is greater than the capacitance adjusting point, if so, increasing the capacitance adjusting point of the capacitance adjusting system, and if less, decreasing the capacitance adjusting point of the capacitance adjusting system.
10. The capacity regulating method of the modular power electronic type amorphous alloy on-load arc-free capacity regulating system according to claim 9, wherein the process of reducing the capacity regulating point of the capacity regulating system comprises the following steps:
for the high-voltage output side, when flowing through the bidirectional thyristor Sa1When the current of the trigger bidirectional thyristor is zeroa2(ii) a When flowing through the bidirectional thyristor Sb1When the current of the trigger bidirectional thyristor is zerob2(ii) a When flowing through the bidirectional thyristor Sc1When the current of the trigger bidirectional thyristor is zeroc2；
For the low-voltage input side, when the current flows through the bidirectional thyristor Sa5And Sa4Trigger the bidirectional thyristor S when the currents are all 0a3(ii) a When flowing through the bidirectional thyristor Sb5And Sb4Trigger the bidirectional thyristor S when the currents are all 0b3(ii) a When flowing through the bidirectional thyristor Sc5And Sc4Trigger the bidirectional thyristor S when the currents are all 0c3；
The process of improving the capacity regulating point of the capacity regulating system comprises the following steps:
for the high-voltage output side, when flowing through the bidirectional thyristor Sa2Trigger the bidirectional thyristor S when the current ofa1(ii) a When flowing through the bidirectional thyristor Sb2When the current of the trigger bidirectional thyristor is zerob1(ii) a When flowing through the thyristor Sc2Is zero, triggers the thyristor Sc1；
For the low-voltage input side, when the current flows through the bidirectional thyristor Sa3When the current of (1) is 0, the bidirectional thyristor S is triggereda5And Sa4(ii) a When flowing through the bidirectional thyristor Sb3When the current of (1) is 0, the bidirectional thyristor S is triggeredb5And Sb4(ii) a When flowing through the bidirectional thyristor Sc3When the current of (1) is 0, the bidirectional thyristor S is triggeredc5And Sc4。
CN202210176637.0A 2022-02-24 2022-02-24 Modular power electronic type amorphous alloy on-load arc-free capacitance regulating system and method Pending CN114530893A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116667721A (en) * 2023-07-31 2023-08-29 江西第二电力设备有限公司 Capacity and voltage regulating method of power transformer and power transformer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116667721A (en) * 2023-07-31 2023-08-29 江西第二电力设备有限公司 Capacity and voltage regulating method of power transformer and power transformer
CN116667721B (en) * 2023-07-31 2023-09-29 江西第二电力设备有限公司 Capacity and voltage regulating method of power transformer and power transformer

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