CN211656086U

CN211656086U - Solar power station with direct current circuit on-off device

Info

Publication number: CN211656086U
Application number: CN202020457744.7U
Authority: CN
Inventors: 刘志刚; 邓长贤; 杜年虎; 白小康; 苏综旗
Original assignee: Shanghai Zhiwei Environmental Technology Co ltd
Current assignee: Shanghai Zhiwei Environmental Technology Co ltd
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2020-10-09
Anticipated expiration: 2030-04-01

Abstract

The utility model discloses a solar power station with direct current circuit on-off device, which comprises a PID recovery device, wherein the grounding end of the PID recovery device is grounded, and a PID breaker is arranged in the PID recovery device; the direct current circuit on-off device comprises a first circuit breaker, a third circuit breaker and a power supply; a first contact of the first circuit breaker is in conductive connection with a first electrode of the solar cell string, a second contact of the first circuit breaker is in conductive connection with a first electrode access end of the inverter, a first contact of the second circuit breaker is in conductive connection with a second electrode of the solar cell string, and a second contact of the second circuit breaker is in conductive connection with a second electrode access end of the inverter; the input end of the power supply is connected with an external power supply, one output electrode of the power supply is connected to a first contact of a PID breaker of the PID recovery device, and the other output electrode of the power supply is respectively connected to one electrode of the control end of the first breaker and one electrode of the control end of the third breaker; and a second contact of the PID breaker is respectively and electrically connected with the control ends of the first breaker, the second breaker and the third breaker.

Description

Solar power station with direct current circuit on-off device

Technical Field

The utility model relates to a photovoltaic power generation field especially relates to a solar power station with direct current circuit on-off device.

Background

When the solar power station generates PID attenuation (potential energy induced attenuation phenomenon), the recovery and prevention of the PID attenuation can be realized by applying voltage (positive voltage or negative voltage) between a direct current end and the ground. Such a voltage may be applied to the inverter, possibly causing damage to the inverter. A direct current breaker is arranged between the inverter and the solar component, and under the condition of pressurization, the direct current breaker is disconnected, voltage is not applied to the inverter, and the purpose of protecting the inverter is achieved. In the prior art, manufacturers set a dc switch for each of the positive and negative electrodes of each solar cell string, which results in the disadvantages of large number of dc switches, high cost and many fault points.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide a solar power station with a dc circuit on-off device, which does not need a large number of dc switches.

In order to achieve the above object, the utility model provides a solar power station with direct current circuit on-off device, including solar cell cluster, dc-to-ac converter, PID recovery unit, direct current circuit on-off device establish ties between solar cell cluster and dc-to-ac converter with control its break-make of electric current, the positive pole of PID recovery unit, negative pole respectively with the positive pole of solar cell cluster, negative pole series connection, the earthing terminal ground connection of PID recovery unit, PID recovery unit embeds there is the PID circuit breaker; the direct current circuit on-off device comprises a first circuit breaker, a third circuit breaker and a power supply;

a first contact of the first circuit breaker is in conductive connection with a first electrode of the solar cell string, a second contact of the first circuit breaker is in conductive connection with a first electrode access end of the inverter, a first contact of the second circuit breaker is in conductive connection with a second electrode of the solar cell string, and a second contact of the second circuit breaker is in conductive connection with a second electrode access end of the inverter;

the input end of the power supply is connected with an external power supply, one output electrode of the power supply is connected to a first contact of a PID breaker of the PID recovery device, and the other output electrode of the power supply is respectively connected to one electrode of the control end of the first breaker and one electrode of the control end of the third breaker; and a second contact of the PID breaker is respectively and electrically connected with the control ends of the first breaker, the second breaker and the third breaker.

As a preferred technical scheme of the invention: the first contact and the second contact are respectively one of a movable contact and a fixed contact, and the first electrode and the second electrode are respectively one of a positive electrode and a negative electrode.

As a preferred technical scheme of the invention: the solar cell string comprises a first solar cell string and a second solar cell string; the direct current circuit on-off device comprises a power supply, a first circuit breaker, a second circuit breaker and a third circuit breaker;

the movable contact of the first circuit breaker is connected with the anode of the first solar cell string, the movable contact of the second circuit breaker is connected with the anode of the second solar cell string, and the movable contact of the third circuit breaker is connected with the cathodes of the first solar cell string and the second solar cell string; the output end of the direct current short circuit on-off device is shunted and is correspondingly connected with the access electrode of the inverter respectively.

One output electrode of the power supply is connected to one end of a stationary contact of a PID breaker of the PID recovery device, and the other output electrode of the power supply is connected to one electrode of control ends of the first breaker, the second breaker and the third breaker respectively, and a movable contact of the PID breaker is electrically connected with the control ends of the first breaker, the second breaker and the third breaker respectively.

As a preferred technical scheme of the invention: and the control end of the PID breaker is in communication connection with the signal end of the controller of the PID recovery device, and the on-off of the PID breaker is controlled by the controller of the PID recovery device.

The utility model has the advantages that: the utility model discloses need not complicated direct current switch, therefore with low costs, the fault point is few, can effectively realize the recovery and the prevention of PID decay moreover, can prevent to apply voltage to the dc-to-ac converter simultaneously, prolongs the life of dc-to-ac converter and the stability of performance.

Drawings

Fig. 1 is a schematic view of the knot of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Referring to fig. 1, the solar power station of the present embodiment mainly includes a solar battery string 1, an inverter 2, and a PID recovery device 3, wherein the solar battery string 1 generates electricity by solar energy, and the generated electric energy is inverted by the inverter 2 and then is merged into a power grid. The PID recovery apparatus 3 of the present embodiment is an existing PID prevention and recovery device (anti id).

The PID recovery device 3 is internally provided with a PID circuit breaker 3-1 (a circuit breaker in the prior art), and the positive electrode and the negative electrode of the PID recovery device 3 are respectively connected in series with the positive electrode and the negative electrode of the solar cell string 1, and the solar cell string 1 of the embodiment includes a first solar cell string 1-1 and a second solar cell string 1-2.

The direct current circuit on-off device comprises a power source 4-1 and three circuit breakers, wherein the number of the circuit breakers of the direct current circuit on-off device 4 is 4-2, 4-3 and 4-4.

The operation process of this embodiment is as follows:

1) the direct current generated by the solar cell 1 is converted into alternating current by the inverter 2 and then is sent to a power grid.

2) When the PID recovery function is modified, the positive and negative electrodes of the PID recovery device 3 are connected to the positive and negative electrodes of any solar cell string (for example, the first solar cell string 1-1), respectively, and the PID recovery device 3 needs to be grounded. When the voltage of the solar battery string obtained by the PID recovery device 3 is tested to a certain value (in the prior art, PID attenuation index is judged), the PID recovery device 3 applies voltage between the negative electrode and the ground to recover and prevent the PID phenomenon of the solar power station. The PID breaker 3-1 is opened when the PID recovery means 3 starts to apply a voltage.

3) The dc circuit switching device 4 is connected in series between the solar cell string and the inverter. The movable contact of the first circuit breaker 4-2 is connected with the anode of the first solar battery string 1-1, the movable contact of the second circuit breaker 4-3 is connected with the anode of the second solar battery string 1-2, and the movable contact of the third circuit breaker 4-4 is connected with the cathodes of the first solar battery string 1-1 and the second solar battery string 1-2; the output end of the direct current short circuit on-off device 4 is divided into 4 paths and correspondingly connected with the original circuit of the inverter 2. Of course, the connection modes of the movable contacts and the fixed contacts of the first circuit breaker 4-2, the second circuit breaker 4-3 and the third circuit breaker 4-4 can be adjusted at will, and the on-off of the solar battery serial inverters connected with the first circuit breaker 4-2, the second circuit breaker 4-3 and the third circuit breaker 4-4 is realized only by the first circuit breaker 4-2, the second circuit breaker 4-3 and the third circuit breaker 4-4.

4) The input end of the power source 4-1 is connected with an external power supply (at this time, the power source may be an AC-DC converter or a constant voltage source), one output electrode of the power source 4-1 is connected to one end of a stationary contact of a PID circuit breaker 3-1 of the PID recovery device, and the other output electrode is connected to one electrode of a control end of a first circuit breaker 4-2, a second circuit breaker 4-3, and a third circuit breaker 4-4 (the control end has two electrodes, the first circuit breaker 4-2, the second circuit breaker 4-3, and the third circuit breaker 4-4 of this embodiment are driven by electromagnetism, so that an electromagnetic coil thereof has two electrodes, and both the two electrodes are the control end). Two output electrodes of the power supply are respectively one of a positive electrode and a negative electrode.

The moving contact of the PID breaker 3-1 is respectively and electrically connected with the other electrode of the control end of the first breaker 4-2, the second breaker 4-3 and the third breaker 4-4;

5) when the PID recovery device 3 starts to work, the PID circuit breaker 3-1 is opened, the control signals of the first circuit breaker 4-2, the second circuit breaker 4-3 and the third circuit breaker 4-4 are opened, and the first circuit breaker 4-2, the second circuit breaker 4-3 and the third circuit breaker 4-4 are opened (taking the control logic as an example, the control modes of the first circuit breaker 4-2, the second circuit breaker 4-3 and the third circuit breaker 4-4 can be in other modes). At this time, the PID recovery device 3 applies a voltage between the negative electrode of the first solar cell string 1-1 and the ground, and since the negative electrodes of the cell string 1-1 and the second solar cell string 1-2 are connected, a voltage is also applied between the negative electrode of the second solar cell string 1-2 and the ground. By analogy, even if more solar cell strings exist, voltage exists between all the solar cell strings and the ground, and the PID recovery function is performed on the whole inverter array cell string. Meanwhile, the first circuit breaker 4-2, the second circuit breaker 4-3 and the third circuit breaker 4-4 are disconnected so that voltage cannot be applied to the inverter, thereby avoiding damage to the inverter.

6) When the PID recovery device 3 tests that the voltage of the first solar cell string 1-1 is larger than a certain value (in the prior art, an index for judging the disappearance of the PID phenomenon is judged), the PID recovery device 3 stops outputting the voltage, the PID breaker 3-1 is switched on, the voltage of the power supply 4-1 is added to control signals of the first breaker 4-2, the second breaker 4-3 and the third breaker 4-4, and the first breaker 4-2, the second breaker 4-3 and the third breaker 4-4 are switched on, so that the solar cell string 1 is connected with the inverter 2, and the solar power station generates power normally.

The control end of the PID breaker 3-1 can be in communication connection with the signal end of the single chip microcomputer (or PLC) of the PID recovery device 3, so that the on-off of the single chip microcomputer of the PID recovery device 3 is controlled.

The details of the present invention are well known to those skilled in the art.

The foregoing has described in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be devised by those skilled in the art in light of the teachings of the present invention without undue experimentation. Therefore, the technical solutions that can be obtained by a person skilled in the art through logic analysis, reasoning or limited experiments based on the prior art according to the concepts of the present invention should be within the scope of protection defined by the claims.

Claims

1. A solar power station with a direct current circuit on-off device comprises a solar battery string, an inverter, a PID recovery device and a direct current circuit on-off device, wherein the direct current circuit on-off device is connected in series between the solar battery string and the inverter for controlling the on-off of the current of the solar battery string and the inverter, the anode and the cathode of the PID recovery device are respectively connected in series with the anode and the cathode of the solar battery string, and the grounding end of the PID recovery device is grounded, which is characterized in that: a PID breaker is arranged in the PID recovery device; the direct current circuit on-off device comprises a first circuit breaker, a third circuit breaker and a power supply;

2. The solar power station of claim 1 wherein: the first contact and the second contact are respectively one of a movable contact and a fixed contact, and the first electrode and the second electrode are respectively one of a positive electrode and a negative electrode.

3. The solar power station of claim 2 wherein: the solar cell string comprises a first solar cell string and a second solar cell string; the direct current circuit on-off device comprises a power supply, a first circuit breaker, a second circuit breaker and a third circuit breaker;

the movable contact of the first circuit breaker is connected with the anode of the first solar cell string, the movable contact of the second circuit breaker is connected with the anode of the second solar cell string, and the movable contact of the third circuit breaker is connected with the cathodes of the first solar cell string and the second solar cell string; the output end of the direct current short circuit on-off device is shunted and is correspondingly connected with the access electrode of the inverter respectively;

4. A solar power station according to any of claims 1-3, characterized in that: and the control end of the PID breaker is in communication connection with the signal end of the controller of the PID recovery device, and the on-off of the PID breaker is controlled by the controller of the PID recovery device.