CN114447985A - Wave power generation multi-source input electric energy conversion system - Google Patents

Abstract

The application discloses wave power generation multisource input electric energy conversion system includes: the power generation rectification module, the collection inversion module and the boosting grid-connected module are sequentially connected; the power generation rectification module comprises a power generation unit, a rectification unit and a measurement protection unit which are sequentially connected, and is used for converting irregular alternating current generated by the wave power generator set into stable direct current; the collection inversion module comprises a measurement protection unit and an inversion unit which are connected in sequence and is used for inverting the direct current; the boost grid-connected module comprises a boost transformer and a measurement protection unit and is used for boosting the inverted voltage; the multi-machine boosting transformer is adopted to carry out boosting processing on alternating current passing through the inversion unit, and the wiring mode is single-bus main wiring, single-bus subsection main wiring or star-shaped main wiring. By means of the mode, the power supply reliability and grid-connected stability of the wave power generation multi-source input electric energy conversion system in different application scenes are improved.

Description

A multi-source input power conversion system for wave power generation

technical field

The present application relates to the technical field of electric energy conversion of wave power generation systems, in particular to a multi-source input electric energy conversion system of wave power generation.

Background technique

At present, the single-unit installed capacity of the wave power generation device in sea trial operation is relatively small, and the capacity is generally tens to hundreds of kW; the single-unit operation is generally used to generate electricity, and the power supply capacity is limited; generally, it is only used for independent loads such as remote islands and reefs and offshore facilities. Or microgrid power supply, and does not participate in the grid-connected operation of the onshore large grid.

Since the current wave power generation device mainly uses a single generator set to supply power to an independent load or a small power grid, it is not necessary to consider the main wiring and grid connection issues. Power generation as a whole shows a trend of developing from a single generator set to a multi-generator set, and from a single device to an array of large-scale development. Through the form of clusters, the system can obtain flexibility, reliability and performance at a relatively low cost. improvement in aspect. Therefore, it is urgent to carry out the design and research of the main wiring of the multi-source input power conversion system of wave power generation that adapts to the needs of grid connection.

SUMMARY OF THE INVENTION

The present application provides a multi-source input power conversion system for wave power generation to solve the problems in the prior art that the single-source input unit of wave power generation has a small capacity, and the main wiring structure and grid-connected operation requirements are not considered.

In order to solve the above technical problems, the present application proposes a multi-source input power conversion system for wave power generation, which includes: a power generation rectifier module, a collection inverter module and a boost grid-connected module connected in sequence; The unit, rectifier unit and measurement protection unit are used to convert the irregular alternating current from the wave power generator set into stable direct current; the collection inverter module, including the measurement protection unit and the inverter unit connected in sequence, is used for the direct current. Inverter; step-up grid-connected module, including a step-up transformer and a measurement and protection unit, used to boost the voltage after the inverter; wherein, a step-up transformer shared by multiple machines is used to boost the AC power passing through the inverter unit. The connection method is single bus main connection, single bus segment main connection or star main connection.

Optionally, in the power generation and rectification module, the measurement protection unit includes a current transformer, a live display, a lightning arrester, a grounding switch, an isolating switch and a handcart-type circuit breaker.

Optionally, in the power generation and rectification module, the power generation unit is a permanent magnet direct drive generator, and the rectification unit is an AC/DC rectifier.

Optionally, the handcart-type circuit breaker 101 is connected to the output end of the permanent magnet generator, and the lower end of the handcart-type circuit breaker 101 is connected to the AC input end of the AC/DC rectifier via the current transformer 106; Read the voltage transformer 102 and current transformer 106 readings.

Optionally, when the current transformer 106 monitors the overcurrent of the branch, the handcart-type circuit breaker 101 disconnects the power generation rectification branch to realize overcurrent protection, and when the voltage transformer 102 monitors the overvoltage of the branch, the arrester 104 realizes the overcurrent protection. Overvoltage protection for the generator output branch; the DC output end of the AC/DC rectifier is connected to the DC collecting bus through the handcart-type circuit breaker 108 and the isolating switches 114, 115, respectively, and the DC collecting bus and the isolating switches 114, 115 are connected in parallel to the single circuit. The phase current transformers 113 and 116 realize the measurement of the output current of the AC/DC rectifier, and display the indications in real time through the live displays 112 and 117. At the same time, the branch circuit overvoltage protection is realized through the lightning arrester 110 connected in parallel at the lower end of the handcart-type circuit breaker.

Optionally, the inverter unit includes a DC/AC inverter; the DC input end of the DC/AC inverter is connected to the DC collecting bus through a primary fuse, a handcart-type circuit breaker and an isolating switch; wherein the primary fuse 206, 208. Lightning arresters 205 and 209 for overvoltage protection, current transformers 203 and 211 for measuring single-phase branch current, live displays 204 and 210 for displaying current transformer readings, and earthing switches 202 and 212 for protection and maintenance are connected in parallel ; The AC output end of the DC/AC inverter is connected to the low-voltage AC bus through the current transformer 213 and the handcart-type circuit breaker 217, and the branch is connected in parallel between the upper end of the handcart-type circuit breaker 217 and the output end of the current transformer 213 Lightning arrester 215 for overvoltage protection, earthing switch 216 for protection and maintenance, and live display 214 for displaying current transformer readings.

Optionally, the step-up grid-connected module includes a handcart-type circuit breaker, a step-up transformer, and a voltage transformer, a current transformer, a live display, a lightning arrester and a grounding switch.

Optionally, the low-voltage side of the step-up transformer 304 is connected to the low-voltage AC bus through the current transformer 302 and the handcart-type circuit breaker 301, and the current transformer 302 is used to measure the low-voltage side branch current and display it through the live display 305; The high-voltage side of 304 is connected to the high-voltage AC bus through the current transformer 308 and the handcart-type circuit breaker 309, and the surge arrester 307 connected in parallel with the output branch of the high-voltage side is used to realize the overvoltage protection of the step-up transformer 304. The handcart-type circuit breaker 309 cooperates to realize the overcurrent protection of the boost output branch.

Optionally, the multi-source input wave power generation rectifier branch is collected in parallel to the DC collecting bus, and finally transmits the electric energy to the shore and grid connection with alternating current through the submarine cable through the inverter branch and the boost grid-connected branch.

Optionally, the input end of the step-up transformer adopts the form of AC collection, and the DC/AC inverter of the inverter branch has the function of synchronously regulating the phase, amplitude and waveform of the output AC voltage of each inverter branch, so as to meet the requirements of the AC collection. Synchronization requirements.

The present application proposes a multi-source input power conversion system for wave power generation, including: a power generation rectifier module, a collection inverter module and a boost grid-connected module connected in sequence; The alternating current is converted into stable direct current; the collection inverter module is used to invert the direct current; the boost grid-connected module is used to boost the voltage after the inversion, and the wave power generation multi-source input electric energy conversion system of the present application can adopt Multiple machines share a step-up transformer to boost the AC power passing through the inverter unit, so as to improve the power supply reliability and grid-connection stability of the wave power generation multi-source input power conversion system in different application scenarios.

Description of drawings

In order to illustrate the technical solutions of the present application more clearly, the following briefly introduces the accompanying drawings used in the implementation manner. Obviously, the accompanying drawings in the following description are only some implementations of the present application, which are common in the art. As far as technical personnel are concerned, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the main wiring structure diagram of the single busbar of the wave power generation multi-source input electric energy conversion system of the present application;

Fig. 2 is the main wiring structure diagram of the single busbar segment of the wave power generation multi-source input electric energy conversion system of the present application;

Fig. 3 is the star-shaped main wiring structure diagram of the wave power generation multi-source input electric energy conversion system of the present application;

Fig. 4 is the structure diagram of the power generation and rectification module of the wave power generation multi-source input electric energy conversion system of the present application;

Fig. 5 is the structure diagram of the DC collection inverter module of the wave power generation multi-source input electric energy conversion system of the present application;

Fig. 6 is the structure diagram of the booster grid-connected module of the wave power generation multi-source input electric energy conversion system of the present application;

FIG. 7 is a structural diagram of the DC collecting bus tie breaker of the wave power generation multi-source input electric energy conversion system of the present application.

Description of reference numerals: 101, 108, 201, 217, 301, 309, 405 - handcart-type circuit breaker, 102 - voltage transformer with secondary winding neutral point grounded, 103, 107, 112, 117, 204, 210 , 214, 305, 310, 407 - live display, 104, 110, 205, 209, 215, 307 - arrester, 105, 109, 111, 118, 202, 212, 216, 303, 306 - earthing switch, 114, 115 , 207, 401, 402, 403, 404 - isolating switch, 106, 213, 302, 308, 406 - three-phase current transformer, 113, 116, 203, 211 - single-phase current transformer, 206, 208 - primary fuse transformer, 304-step-up transformer, positive pole of DC collecting bus-DCBus+, negative pole of DC collecting bus-DC Bus-, low-voltage AC bus-LV AC Bus, medium/high-voltage AC bus-M/HV ACBus.

Detailed ways

In order for those skilled in the art to better understand the technical solutions of the present application, the following describes the multi-source input electric energy conversion system for wave power generation provided by the present application in further detail with reference to the accompanying drawings and specific embodiments.

In view of the shortcomings of the above-mentioned wave power generation single-source input unit with small capacity, no consideration of the main wiring structure and grid-connected operation requirements, the present application analyzes the array distribution from three aspects: power generation rectifier module, collection inverter module and boost grid-connected module. The main wiring structure of the multi-source input wave power conversion system is optimized. At the same time, considering the influence factors such as sea wave conditions, installed capacity and generator set array form, three optimal main wiring schemes under different application scenarios are proposed to solve the current situation. The single-source input wave power generation platform cannot take into account the flexibility of the main wiring of the power conversion system and the reliability of grid connection when the multi-source input is present.

The present application proposes a multi-source input power conversion system for wave power generation. Please refer to FIGS. 1-7. In this embodiment, the multi-source input power conversion system for wave power generation may include: power generation and rectification modules connected in sequence, a collection inverter modules and boost grid-tied modules.

The power generation and rectification module, including a power generation unit, a rectification unit and a measurement protection unit connected in sequence, is used to convert the irregular alternating current generated by the wave power generator set into a stable direct current;

A collection of inverter modules, including a measurement protection unit and an inverter unit connected in sequence, are used to invert the direct current;

Step-up grid-connected module, including step-up transformer and measurement protection unit, used to boost the voltage after inverter;

Among them, a booster transformer shared by multiple machines is used to boost the AC power passing through the inverter unit, and the connection method can be single bus main connection, single bus segment main connection or star main connection. specifically:

As shown in FIG. 1 , FIG. 1 is a main wiring diagram of a single busbar of the multi-source input electric energy conversion system of wave power generation according to the present application. In the form of single bus main connection, the multi-source input wave power generation rectifier branches (n total) are collected in parallel to the DC collecting bus, and finally the high-voltage alternating current is passed through the inverter branch and the boost grid-connected branch. Submarine cables transmit power to shore and connect to the grid.

The layout is simple in structure, low in investment cost, but not very reliable. Although when a power generation branch fails, only the branch circuit breaker and isolating switch of the corresponding branch can be actuated to remove the faulty branch while other power generation rectifier branches maintain normal operation. When the booster power transmission branch fails, all wave power generator sets connected to the DC collecting bus will be out of operation, and the wave power generation platform can only be powered off for maintenance at this time. Therefore, this main wiring method is suitable for wave power generation farms with relatively stable sea wave conditions, small installed capacity and relatively short distance from the shore, so as to reduce the maintenance cost and workload in the later period.

As shown in Fig. 2 and Fig. 7, Fig. 2 is the main wiring structure diagram of the single busbar segment of the wave power generation multi-source input electric energy conversion system of the present application; Fig. 7 is the direct current collection bus connection of the wave power generation multi-source input electric energy conversion system of the present application Circuit breaker diagram. In the form of single bus segment main wiring, the power generation rectifier branches on each segment bus (there are n generator sets in parallel on each segment bus, that is, n power generation rectifier branches) are collected in parallel to the DC collecting bus. On the upper side, each segmented DC collecting bus is connected through the branch circuit of the bus tie breaker, and the switching of the connected state between the respective segmented buses is realized by controlling the on-off state of the isolating switch and the bus tie breaker, and each segmented DC collecting bus is independently connected. The inverter branch of the inverter converts the DC power into AC low-voltage power and collects it on the low-voltage AC bus.

It should be noted that since the input end of the step-up transformer adopts the form of AC collection, the DC/AC inverter of the inverter branch should have the function of synchronously regulating the phase, amplitude and waveform of the output AC voltage of each inverter branch, so that the Meet the synchronization requirements of communication aggregation.

The difference between the single-busbar segmented connection method and the single-busbar connection method is that when the DC collecting busbar or the inverter branch fails, the outage range can be reduced. It is only necessary to disconnect the branch on the side of the faulty segmented busbar. At this time, the system still remains. It can maintain a certain power transmission capacity to the outside world. Since each segmented busbar is connected by the bus tie breaker, in order to reduce the construction cost, the power generation branches should be distributed as compactly as possible. The working state of the segment bus enables the wave power generation device to maintain a certain operational reliability in the scene where the sea area wave conditions change greatly. The distribution of each generator set array is relatively uniform and compact, and it is a scene in which the left and right or front and rear bidirectional arrays are distributed.

As shown in Fig. 3, Fig. 3 is the structure diagram of the star-shaped main connection of the multi-source input electric energy conversion system of the wave power generation of the present application; the star-shaped main connection is adopted. The main connection form adopts the connection form of segmented bus DC collecting to DC collecting bus, collecting to low-voltage AC bus through independent inverter branch, and finally boosting to high-voltage power transmission and grid connection. The same as the inverter selection, it should have the function of synchronously regulating the phase, amplitude and waveform of the output AC voltage of each inverter branch.

The star-shaped main connection is characterized by high independence between the branches. Generally, no backup connection is used. When a branch device fails, the corresponding branch can be removed. The reliability of power supply is higher than that of single bus connection and single The busbar segment wiring form is slightly higher, but the investment cost is correspondingly higher. Compared with the single bus connection form, the star connection method reduces the risk of system outage when the inverter link fails, and improves the power supply reliability and stability of the power generation system by introducing a star structure in the inverter collection link. The main wiring structure of the single busbar section is different in that there is no bus tie breaker branch used to connect the section busbars, and each section busbar can only be in an independent working state, so there is no need for power outage maintenance when the bus tie breaker fails. , with higher independence. That is to say, the main connection form is suitable for the triangular array layout form where the seawater flow direction changes frequently, the wave conditions change greatly, and the multi-source input power generation branches are densely distributed.

Different main wiring schemes have their own advantages and disadvantages, which should be determined according to the analysis of power plant scale, operation reliability, economy, etc. The characteristics of the preferred method proposed in this application are shown in the following table:

Table 1 Comparison of preferred methods for main wiring

The different main wiring schemes of this application have been introduced above. The following is a detailed description of the system modules:

The power generation rectifier module is connected to the DC busbar through the power generation unit, the rectifier unit and the measurement protection unit; the collection inverter module is connected to the low voltage AC busbar through the measurement protection unit and the inverter unit; Connected to the medium and high voltage AC bus.

1) Generating rectifier module

The function of the rectifier unit is to convert the irregular alternating current from the wave power generator set into stable direct current. In this embodiment, the power generation unit can be a permanent magnet direct drive generator, and the rectifier unit can be an AC/DC rectifier. Each single-source generator set is connected in parallel to the DC collector bus through the AC/DC rectifier. The selection of the DC collector bus voltage should prevent the DC collector bus voltage distortion and grid connection point voltage fluctuations. Refer to the same type of offshore wind power installations.

As shown in FIG. 4 , FIG. 4 is a structural diagram of the power generation and rectification module of the wave power generation multi-source input power conversion system of the present application. The power generation rectifier module includes permanent magnet direct drive generator, AC/DC rectifier, current transformer for measurement and protection, live display, lightning arrester, grounding switch, isolation switch and handcart circuit breaker and other measurement protection units.

Among them, the handcart-type circuit breaker 101 is connected to the output end of the permanent magnet generator, and the lower end of the handcart-type circuit breaker 101 is connected to the AC input end of the AC/DC rectifier through the current transformer 106; the live displays 103 and 107 are respectively used for reading Voltage transformer 102 and current transformer 106 are indicated.

When the current transformer 106 monitors the branch overcurrent, the handcart-type circuit breaker 101 disconnects the power generation rectifier branch, and when the voltage transformer 102 monitors the branch overvoltage, the arrester 104 realizes the overvoltage of the generator output branch. voltage protection; the DC output end of the AC/DC rectifier is respectively connected to the positive and negative DC collecting busbars through the handcart-type circuit breaker 108 and the isolating switches 114 and 115, and the single-phase current transformer 113 connected in parallel with the isolating switches 114 and 115 through the positive and direct current collecting busbars and the isolating switches 114 and 115. 116 realizes the measurement of the output current of the AC/DC rectifier, and displays the indications in real time through the live displays 112 and 117. At the same time, the branch circuit overvoltage protection is realized through the lightning arrester 110 connected in parallel at the lower end of the handcart-type circuit breaker.

2) Assemble inverter modules

At present, there are two ways to collect the output power of the power generation and rectification branch of the wave power generation device: AC collection and DC collection. However, because the AC collection has relatively high requirements on the branch voltage, frequency and phase, the DC collection only needs to collect the DC collection bus voltage. Therefore, this embodiment adopts the form of DC collection.

The inverter unit may include a DC/AC inverter; as shown in FIG. 5 , FIG. 5 is a structural diagram of the DC collection inverter module of the wave power generation multi-source input power conversion system of the present application. The DC input end of the DC/AC inverter is connected to the DC collecting bus through a primary fuse, a handcart-type circuit breaker and an isolating switch. The primary fuses 206 and 208 are connected in parallel with lightning arresters 205 and 209 for overvoltage protection. Current transformers 203 and 211 for phase and branch currents, live displays 204 and 210 for displaying current transformer readings, and earthing switches 202 and 212 for protection and maintenance; The busbar is connected, and the upper end of the circuit breaker 217 and the output end of the current transformer 213 are connected to the branch circuit in parallel with the surge arrester 215 for overvoltage protection, the grounding switch 216 for protection and maintenance, and the live display 214 for displaying the current transformer reading.

3) Boost grid-connected module

The purpose of the step-up grid-connected module is to boost the low-voltage AC voltage after the inverter. At present, the marine energy power generation unit generally adopts the form of "one machine, one change", that is, one generator corresponds to one transformer, but due to the current wave The capacity of the generator set of the power generation device is relatively small, and considering the complexity of the offshore environment and the corresponding operation and maintenance costs in the later stage, this embodiment adopts the form of multiple machines sharing a transformer to increase the AC voltage collected by the inverter. In addition, because the current multi-source input wave power generation platform is relatively close to the island or offshore, and the system structure of the AC transmission mode is relatively simple, the technology is relatively mature, the reliability is high, and the cost is low. The transmission method of AC power transmission ashore.

As shown in FIG. 6 , FIG. 6 is a structural diagram of the booster grid-connected module of the wave power generation multi-source input electric energy conversion system of the present application. The step-up grid-connected module includes a handcart-type circuit breaker, a step-up transformer, and a voltage transformer, a current transformer, a live display, a surge arrester and an earthing switch.

Among them, the low-voltage side of the step-up transformer 304 is connected to the low-voltage AC bus through the current transformer 302 and the handcart-type circuit breaker 301, and the current transformer 302 is used to measure the low-voltage side branch current and display it through the live display 305; The high-voltage side is connected to the high-voltage AC bus through the current transformer 308 and the handcart-type circuit breaker 309, and the overvoltage protection of the step-up transformer is realized by using the lightning arrester 307 connected in parallel with the output branch of the high-voltage side. The circuit breaker 309 cooperates to realize the overcurrent protection of the boost output branch.

It should be noted that the power generation and rectification module may include multiple power generation and rectification branches, and the collective inverter module may include multiple collective inverter branches, but the boost grid-connected module only includes one boost and grid-connected branch.

To sum up, compared with the main wiring technology of the existing wave power generation single-source input electric energy conversion system, the technical solution of the present application provides the multi-source input of wave power generation from three links: the power generation rectification module, the collection inverter module and the boost grid-connected module. The main wiring structure of the power conversion system is optimized, and corresponding measurement and protection measures are designed for each branch. There are three different main connection options: bus main connection form, single bus segment main connection form and star main connection form, to adapt to the array distribution layout and main connection form in different application scenarios, so as to improve the multi-source input of wave power generation Power supply reliability and grid-connected stability of power conversion system in different application scenarios.

It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, for the convenience of description, the drawings only show some but not all structures related to the present application. The step numbers used in the text are only for the convenience of description, and are not intended to limit the order in which the steps are performed. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes For other steps or units inherent to these processes, methods, products or devices.

Reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor a separate or alternative embodiment that is mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

The above description is only an embodiment of the present application, and is not intended to limit the scope of the patent of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present application, or directly or indirectly applied to other related technologies Fields are similarly included within the scope of patent protection of this application.

Claims (10)

1. A wave power generation multi-source input electric energy conversion system is characterized by comprising: the power generation rectification module, the collection inversion module and the boosting grid-connected module are sequentially connected;

the power generation rectification module comprises a power generation unit, a rectification unit and a measurement protection unit which are sequentially connected, and is used for converting irregular alternating current generated by the wave power generator set into stable direct current;

the collection inversion module comprises a measurement protection unit and an inversion unit which are connected in sequence and is used for inverting the direct current;

the boosting grid-connected module comprises a boosting transformer and a measurement protection unit and is used for boosting the inverted voltage;

the boosting transformer is shared by multiple machines to boost the alternating current passing through the inversion unit, and the wiring mode is single-bus main wiring, single-bus sectional main wiring or star-shaped main wiring.

2. A wave power generation multi-source input power conversion system according to claim 1,

in the power generation rectification module, the measurement protection unit comprises a current transformer, a live display, a lightning arrester, a grounding switch, an isolating switch and a handcart type circuit breaker.

3. A wave power generation multi-source input power conversion system according to claim 2,

in the power generation rectifying module, the power generation unit is a permanent magnet direct drive generator, and the rectifying unit is an AC/DC rectifier.

4. A wave power generation multi-source input power conversion system according to claim 3,

the handcart type circuit breaker (101) is connected with the output end of the permanent magnet generator, and the lower end of the handcart type circuit breaker (101) is connected with the alternating current input end of the AC/DC rectifier through a current transformer (106); the live displays (103, 107) are respectively used for reading the readings of the voltage transformer (102) and the current transformer (106).

5. A wave power generation multi-source input power conversion system according to claim 4,

when a current transformer (106) monitors that a branch circuit is in overcurrent, a handcart type circuit breaker (101) disconnects a power generation rectifying branch circuit to realize overcurrent protection, and meanwhile, when a voltage transformer (102) monitors that the branch circuit is in overvoltage, an arrester (104) realizes overvoltage protection on an output branch circuit of a generator;

the direct current output end of the AC/DC rectifier is respectively connected to a direct current collection bus through a handcart type circuit breaker (108) and isolating switches (114, 115), the output current of the AC/DC rectifier is measured through single-phase current transformers (113, 116) which are connected with the direct current collection bus and the isolating switches (114, 115) in parallel, readings are displayed in real time through electrified displays (112, 117), and branch overvoltage protection is realized through a lightning arrester (110) which is connected with the lower end of the handcart type circuit breaker in parallel.

6. A wave power generation multi-source input power conversion system according to claim 5, characterized in that

The inversion unit comprises a DC/AC inverter; the DC input end of the DC/AC inverter is connected with a DC collection bus through a primary fuse, a handcart type circuit breaker and an isolating switch;

wherein, the primary fuses (206, 208), the lightning arresters (205, 209) playing the role of overvoltage protection, the current transformers (203, 211) for measuring the current of the single-phase branch circuit, the live displays (204, 210) for displaying the indication number of the current transformers and the grounding switches (202, 212) for protecting and overhauling are connected in parallel; the AC output end of the DC/AC inverter is connected with a low-voltage AC bus through a current transformer (213) and a handcart type circuit breaker (217), and a lightning arrester (215) which has an overvoltage protection function, a grounding switch (216) for protecting and overhauling and an electrified display (214) for displaying the indication number of the current transformer are connected in parallel by a connecting branch between the upper end of the handcart type circuit breaker (217) and the output end of the current transformer (213).

7. A wave power generation multi-source input power conversion system according to claim 6,

the boosting grid-connected module comprises a handcart type circuit breaker, a boosting transformer, a voltage transformer, a current transformer, a live display, a lightning arrester and a grounding switch.

8. A wave power generation multi-source input power conversion system according to claim 7,

the low-voltage side of the step-up transformer (304) is connected with a low-voltage alternating current bus through a current transformer (302) and a handcart type circuit breaker (301), and the current of a branch circuit at the low-voltage side is measured by the current transformer (302) and displayed by a charged display (305);

the high-voltage side of the step-up transformer (304) is connected with a high-voltage alternating current bus through a current transformer (308) and a handcart type circuit breaker (309), overvoltage protection on the step-up transformer (304) is realized by utilizing a lightning arrester (307) connected with a high-voltage side output branch in parallel, and meanwhile overcurrent protection of the step-up output branch is realized through the cooperation of the current transformer (308) and the handcart type circuit breaker (309).

9. A wave power generation multi-source input power conversion system according to claim 8,

the multi-source input wave power generation rectification branch is collected to a direct current collection bus in a parallel connection mode, and finally electric energy is transmitted to shore for grid connection through an alternating current through a submarine cable through an inversion branch and a boosting grid connection branch.

10. A wave power generation multi-source input power conversion system according to claim 9,

the input end of the step-up transformer adopts an alternating current collection form, and the DC/AC inverter of the inversion branch circuits has the function of synchronously regulating and controlling the phase, amplitude and waveform of alternating current voltage output by each inversion branch circuit so as to meet the synchronous requirement of alternating current collection.

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