KR20210141298A - Photovoltaic equipment - Google Patents

Abstract

The present invention relates to a photovoltaic power generation apparatus capable of opening and closing a high DC voltage by a parallel MUX selection switch with a field-effect transistor. Generally, direct-current power transmission and distribution devices have a plurality of direct-current circuits configured to output power to a system or the like by gathering power flowing through the plurality of direct-current circuits by a single circuit, and input units of the plurality of circuits are provided with a plurality of switches switching direct-current (+) power to shut off power if faults such as a short circuit and repair inspection occur. Specifically, the present invention provides a photovoltaic power generation apparatus capable of opening and closing a high DC voltage by a parallel MUX selection switch with a field-effect transistor to provide an expensive high-voltage parallel MUX selection switch capable of opening and closing a high voltage or a parallel MUX selection circuit (bypass) of a semiconductor type for removing an arc and a high voltage for only one circuit among the plurality of circuits to protect the plurality of switches through the parallel MUX selection switch.

Description

Solar power generation device capable of opening and closing DC high voltage with field effect transistor parallel MUX selection switch {PHOTOVOLTAIC EQUIPMENT}

The present invention relates to a photovoltaic device capable of opening and closing DC high voltage with a field effect transistor parallel MUX selection switch. In order to protect a plurality of switches (multiple relays) by providing a semiconductor-type parallel MUX selection circuit (Bypass) or an expensive high-voltage parallel MUX selection switch that can open and close high voltage only in one circuit of the circuit to remove high voltage and arc It is a technology related to a photovoltaic power generation device that can open and close DC high voltage with an effect transistor parallel MUX selection switch.

In general, in a photovoltaic system, solar cell modules that convert solar energy into electrical energy are connected in series, and one side of the series-connected solar cell module is connected to each other and jointly grounded (-), and the other side is connected in series. The (+) side of each solar cell module (SM) connected to each other is jointly connected with a binder. The (+) DC power string bound by the binder goes through the isolator and the leakage current breaker into the inverter, an electric device, and is converted into AC power for use.

And, in general, each solar cell module is composed of a plurality of solar cells. For example, when a typical solar cell module consists of 24 solar cells, the positive (+) terminal and the negative (-) terminal under sunlight ) produces about 40V between the terminals. In fact, a high voltage of 600 ~ 1000V and a current of tens to hundreds of amps (A) flows between the (+) power string and the ground (-) of the photovoltaic array in which a plurality of solar cell modules are connected in series and parallel.

In such a photovoltaic power generation system, a disconnector is installed between the string and the inverter to cut off the high-voltage string DC power to which the string of the tanyang photovoltaic power generation array is connected for failure or maintenance.

In the conventional disconnector, a relay or a circuit breaker having a mechanical contact is usually used.

However, when switching a string (+) DC power with hundreds of volts DC voltage and several tens to hundreds of amps using the mechanical contact of the disconnector, DC power has no current zero point like AC power. Therefore, a direct current arc is easily generated between the contact points of the disconnector, and the arc generated once lasts for a considerable time until the contact gap is sufficiently separated. The continuous arc not only shortens the life of the disconnector by melting the contact point of the disconnector, but also poses a risk of a fire accident.

So, as an amount to solve the above problems, registration number 10-1777195 is

A plurality of solar panels (S1) separately connected to a plurality of groups of circuits, a plurality of input terminals, a plurality of fuses and circuit breakers, a plurality of diodes, and an output terminal for combining the power output from the plurality of diodes into one In the connection panel,

a plurality of bypass circuits for bypassing the power input from the plurality of fuses to the plurality of diodes and outputting them to an output terminal; a plurality of bypass switches for opening and closing the bypass circuit according to a control signal from a control unit, and a measuring unit for monitoring a state of a power value flowing through the circuit;

By determining the state of the circuit by the measurement unit, the bypass switch is opened and closed, and the power input to the fuse is simultaneously input to the diode and the plurality of bypass switches.

During normal and equal power generation in each of the plurality of groups, any

When the measured value measured through the measuring unit in one group is out of the preset voltage range, the normally generated power is abnormally flowing.

It is determined that the reverse current flows in the circuit direction, and the bypass switch is turned off to block the reverse current by the diode, and when the power value measured through the measuring unit during monitoring is within the preset voltage range, it is determined that it is normal power production, It is a configuration in which the bypass switch is turned on so that power is output to the output terminal through the bypass circuit.

As described above, each bypass circuit is provided in a plurality of circuits, and then a bypass switch is provided in each of the bypass circuits, thereby increasing the product price. This increases the volume, increases storage and transportation costs, and has problems such as cumbersome manufacturing due to the need to connect a plurality of bypass switches.

(Patent Document 1) 1. Republic of Korea Patent Publication No. 10-2017-0113836

In view of the above conventional problems, the present invention provides a semiconductor-type parallel MUX for removing high voltage and arcing from only one circuit among the plurality of circuits by installing on/off switches in each of the plurality of circuits in the photovoltaic device. In order to protect a plurality of switches by providing an expensive high voltage parallel MUX selection switch capable of opening and closing a selection circuit (bypass) or high voltage, a photovoltaic device capable of opening and closing DC high voltage with a field effect transistor parallel MUX selection switch is provided.

A detailed configuration will be described with reference to the accompanying drawings.

In the high voltage switch capable of opening and closing multiple inputs,

The electric power flowing through the plurality of DC circuits 10 is collected into one circuit and converted into a system.

Configure the circuit to output,

A relay 20 for turning on/off circuits is connected to the plurality of DC circuits 10, and a relay 20a connected to any one circuit 10a among the plurality of circuits 10 is selected as a parallel MUX The parallel MUX selection circuit 30 is connected, but the parallel MUX selection switch 40 is turned on/off according to the control signal of the control unit 100 to the parallel MUX selection circuit 30;

Connecting the input short circuit prevention diode (a') to the input part (30a) of the parallel MUX selection circuit (30) to which the current is input to the parallel MUX selection switch (40);

One side 50a of the second parallel MUX selection circuit 50 is respectively connected to the plurality of circuits 10 except for the circuit 10a connecting the parallel MUX selection circuit 30 and the parallel MUX selection switch 40. do

The other side 50b of the second parallel MUX selection circuit 50 is combined into one parallel MUX selection circuit corresponding to between the output part 30a of the parallel MUX selection circuit 30 and the diode a' ( 30) is connected to output power,

It consists of a diode (a) connected to each of the plurality of second parallel MUX selection circuits (50) to prevent an input short circuit, and a measuring unit (130) that monitors the state of the flowing power value of the circuit.

In a state in which the plurality of relays 20 and the parallel MUX selection switch 40 connected to the plurality of circuits 10 according to the control signal of the control unit 100 are kept in an on' state

In the process of sequentially turning on/off the plurality of relays 20 for a set time through the control unit 100, the power passing through the parallel MUX selection switch 40 is measured through the detection unit 140,

When the measured value measured in one circuit is outside the preset voltage, current, leakage current, etc. range, it is determined that there is a problem in the circuit 10 out of the range such as voltage, current, leakage current, etc. 10) is to cut off the power by turning off the relay 20.

The relay corresponds to a latching relay, and the parallel MUX selection switch corresponds to a MOS-FET switch.

The latching relay has a dual coil and at least one three-way switching mechanical contact and a permanent magnet capable of maintaining the circuit even when the current of the control circuit is cut off, and the three-way switching mechanical contact is the dual It is characterized in that it is opened and closed by a set (SET) signal that excites any one of the coils and a relay signal of a reset (REST).

The parallel MUX selection switch 40 corresponds to a bypass switch,

The parallel MUX selection circuit 30 corresponds to a bypass circuit,

The second parallel MUX selection circuit 50 corresponds to a second bypass circuit.

As described above, the present invention provides a semiconductor-type parallel MUX selection circuit for removing high voltage and arcing from only one circuit among the plurality of circuits by installing on/off switches in each of the plurality of circuits in the photovoltaic device. By protecting a plurality of switches by providing an expensive high voltage parallel MUX selection switch that can open and close (bypass) or high voltage,

By sharing one parallel MUX selection circuit with multiple circuits, the product price is low, by providing one parallel MUX selection switch, the failure probability is low, and by providing one parallel MUX selection switch, the volume is small, so storage and transportation costs are low. This inexpensive and very beneficial invention is convenient to manufacture by wiring only one parallel MUX selection switch.

In addition, by using a latching relay, the latching relay does not open and close by itself even if there is no driving voltage due to a power failure or a power supply failure. The gate of the switching device can be driven in advance for a predetermined time by using a photovoltaic output photocoupler operating with its own DC power supply. Due to this, the parallel MUX selection protection circuit of the semiconductor switching element operates with high reliability even if there is no additional driving voltage due to a power failure or a power supply failure.

1 is an overall flowchart of an embodiment of a photovoltaic device capable of opening and closing DC high voltage with a field effect transistor parallel MUX selection switch.
Figure 2 is a flow chart showing the operation state of the parallel MUX selection switch and relay of the present invention.
3 is an explanatory diagram showing a flowchart of the present invention;
4A) is a parallel-parallel MUX selection protection circuit of a DC power disconnector according to an embodiment of the present invention.

Let's take a look at the configuration with reference to the accompanying drawings, and look at an embodiment according thereto.

In a photovoltaic device capable of opening and closing DC high voltage with a field effect transistor parallel MUX selection switch,

The electric power flowing through the plurality of DC circuits 10 is collected into one circuit and converted into a system.

Configure the circuit to output,

A relay 20 for turning on/off circuits is connected to the plurality of DC circuits 10, and a relay 20a connected to any one circuit 10a among the plurality of circuits 10 is selected as a parallel MUX The parallel MUX selection circuit 30 is connected, but the parallel MUX selection switch 40 is turned on/off according to the control signal of the control unit 100 to the parallel MUX selection circuit 30;

Connecting the input short circuit prevention diode (a') to the input part (30a) of the parallel MUX selection circuit (30) to which the current is input to the parallel MUX selection switch (40);

One side 50a of the second parallel MUX selection circuit 50 is respectively connected to the plurality of circuits 10 except for the circuit 10a connecting the parallel MUX selection circuit 30 and the parallel MUX selection switch 40. do

The other side 50b of the second parallel MUX selection circuit 50 is combined into one parallel MUX selection circuit corresponding to between the output part 30a of the parallel MUX selection circuit 30 and the diode a' ( 30) is connected to output power,

It consists of a diode (a) connected to each of the plurality of second parallel MUX selection circuits (50) to prevent an input short circuit, and a measuring unit (130) that monitors the state of the flowing power value of the circuit.

Looking at the embodiment of the configuration as follows,

A diode a is connected to each of the plurality of second parallel MUX selection circuits 30 and 50 , and a diode a' is connected to one circuit 10a among the plurality of circuits 10 . That is, a diode is connected to each circuit 10 .

In this case, the power flowing to the parallel MUX selection circuit and the second parallel MUX selection circuit is in a state in which reverse flow is prevented because the diodes are connected respectively.

There is a measurement unit 130 that monitors the state of each power value flowing through the plurality of circuits 10, and the measurement unit 130 determines the state of the circuit 10 and selects a parallel MUX through the control unit 100 Open and close the switch 40 and the relay 20 connected to the plurality of circuits 10

In a state in which power is simultaneously input to the plurality of circuits 10 from a plurality of DC power input units,

When the measured value measured in any one circuit through the measuring unit 130 while normally outputting power from the plurality of circuits 10 is out of a preset voltage range, current range, or leakage current range,

Turn on the parallel MUX selection switch 40 connected to the parallel MUX selection circuit 30 to cut off the power flowing in the circuit 10 out of the voltage range or current range or leakage current range, and then turn on the voltage range or current range or leakage The power of the circuit 10 out of the current range

In the state that it is output to the output terminal through the parallel MUX selection circuit 30, the relay 20 connected to the circuit 10 out of the voltage range, the current range, or the leakage current range is turned off (after the parallel MUX selection switch is turned off) After turning off), the parallel MUX selection switch 40 is turned off to cut off the power supply of the circuit out of the voltage range, current range, or leakage current range.

When the set time elapses after the power is cut off of the circuit 10 out of the voltage range, current range, or leakage current range, the parallel MUX selection switch 40 is turned on, and the power value measured through the measuring unit 130 is set in advance. When it exists within the voltage range, current range, or leakage current range, it is determined that it is a normal power supply and the off relay is turned on' so that power is output to the output terminal via the off relay, and then the control signal of the control unit 100 Accordingly, the parallel MUX selection switch 40 is turned off.

Next, by monitoring the plurality of circuits 10 in the parallel MUX selection circuit, it is possible to determine whether there is a failure.

In a state in which the plurality of relays 20 and the parallel MUX selection switch 40 connected to the plurality of circuits 10 according to the control signal of the control unit 100 are kept in the on' state

In the process of sequentially turning on/off the plurality of relays 20 for a set time through the control unit 100, the power passing through the parallel MUX selection switch 40 is measured through the detection unit 140,

When the measured value measured in one circuit is out of the preset voltage range or current range or leakage current range, it is determined that there is a problem in the circuit 10 out of the voltage range or current range or leakage current range, and the circuit with the problem (10)

The relay 20 is turned off to cut off the power.

An example of the configuration is as follows (see FIG. 5).

The power output to the output circuit 30b of the parallel MUX selection switch 40 is measured through the detection unit 140 .

And when the plurality of relays 50 connected to the plurality of circuits 10 are turned off through the control unit 100 in a preset order and then turned on after a set time, they are turned off in the off process for a predetermined time.

The power of the circuit 10 is output to the output terminal through the parallel MUX selection circuit 30 .

By configuring in this way, a plurality of circuits 10 can be checked through one detection unit 140, so the manufacturing cost is low, and a problematic circuit 10 line can be easily and conveniently found, so that quick maintenance is possible.

In the description, when the plurality of relays and the parallel MUX selection switch 40 are in the on state, the power input from the input unit flows in the direction of the plurality of relays (corresponding to the switches in the drawing), respectively.

The parallel MUX selection switch is temporarily closed only when the plurality of relays 20 are operated, and after the relay operation is completed, the parallel MUX selection switch is cut off (off).

This is because, when the parallel MUX selection switch is turned off, the power input from the input unit flows only in a plurality of relay directions, and does not flow to the parallel MUX selection switch 40 .

(Power moves in the direction of the relay that receives less resistance as the resistance of the diode and parallel MUX selection switch works)

In the present invention, the MOS-FET is a switching device for power circuits of various electronic devices because high-speed switching is possible and gate driving is relatively simple. The parallel MUX selection switch 40 of the present invention uses a MOS-FET device (refer to Registration No. 10-1209639 for a MOS-FET gate driving circuit and driving method).

The MOS-FET device is capable of high-speed switching of high-voltage, high-current, and has a simple driving method.

However, if the current continuously flows, heat is severe and the device is destroyed.

In the present invention, the MOS-FET device is used to conduct electricity only for a short time when the arc is generated, and in the section in which current continuously flows in which heat is generated, the advantage of removing heat by using the relay contact is used.

A semiconductor-type parallel MUX selection circuit (Bypass) to eliminate voltage and arc or an expensive high-voltage MOS-FET capable of opening and closing high voltage is used for switching, and a low-voltage relay that is inexpensive and easy to obtain when large currents are constantly flowing. By using the mechanical contact of

The relay 20 of the present invention is a latching relay, and the latching relay RL1 has a dual coil and at least one or more 3 switching mechanical contacts. It is preferable to connect the contacts in parallel to increase the contact capacity. and

The mechanical contact of 3-way switching can be reliably opened and closed by the set (SET) signal that excites any one of the double coils and the relay signal of the reset (REST).

In addition, by using the double coil latching relay (RL1) that can maintain the open/closed state without a constant driving power source, the latching relay does not open and close by itself even if there is a power outage or a power supply failure, so safety accidents such as fire are prevented. .

The latching relay RL1 (see FIG. 4) is preferably a dual coil and at least one or more 3-way switching mechanical contacts to increase the contact capacity by connecting the contacts in parallel, and the 3-way switching mechanical contacts are preferable. The contact point is any one of the double coils.

It can be reliably opened and closed by the excitation SET signal and the reset relay signal. In addition, by using the double-coiled latching relay (RL1) that can maintain the open/closed state without a constant driving power source, the latching relay does not open and close by itself even if there is a power outage or a power supply failure, thereby preventing safety accidents such as fire.

In addition, the photocoupler OP1 is preferably a photocoupler OP1 having a photocell output function capable of operating the gate drive signal with DC power (H/V INPUT & H/V OUTPUT) without external driving power supply. Unlike a general photocoupler, the photovoltaic output photocoupler OP1 has a voltage that can turn on the semiconductor switching element Q1 on the insulated output side and

A current is generated by itself to drive the semiconductor switching element Q1 without an external driving power source. Therefore, even if there is a power failure or a power supply device fails, the semiconductor switching element Q1 can be controlled, and accordingly, the DC power disconnector 100 to which the parallel-parallel MUX selection protection circuit of the semiconductor switching element Q1 is added. It can be operated with high reliability.

5 is an operation time chart of each component of the DC power disconnector 100, and FIG. 3 (a) is an operation time of the semiconductor switching element Q1 operated by the element control signal B/P1 of the control device. Time chart, Fig. 3b is an operation time time chart of the mechanical contact of the latching relay RL1 while the semiconductor switching element Q1 operates for a predetermined time, Fig. 3c is the semiconductor switching element Q1 operates, At this time, when the latching relay RL1 operates, the DC voltage applied to the mechanical contact part of the latching relay RL1 is schematically shown.

The technology related to the latching relay and the like is described in detail in Publication No. 10-2017-0113836.

Control is, as shown, the power transmitter 11 subgroups (SG1) to (SGn) of at least two or more series-connected power transmitters 11, and the power transmitter 11 subgroup Power measuring means 13 and power measurement values (P1) to (Pn) for measuring power by measuring the voltage and current of (SG1) to (SGn), and each of the power transmitting units (including the power generating unit) subgroups (SG1) to (SGn) installed in the vicinity of the solar radiation measurement sensor 14 and the measured amount of information (L1) to (Ln), and each of the power transmitter subgroups (SG1) to (SGn) at a set time interval between each other Comparing the measured power values (P1 to Pn), if it is in an unbalanced state, it is judged as abnormal,

*In addition, the amount of power (Pc) obtained by correcting the area of the small group (SG1) of the power transmitting unit 11 to the measured power value (P1) of the small group (SG1) and the information value (L1) measured at the location (Pc) ) and the control unit 20 for determining and processing the operating state and deterioration of the power transmission unit small group (SG1) ~ (SGn) and,

Communication in which the control unit 20 transmits an alarm message and data of the operation state and deterioration state of each of the power transmitting units 11 small groups SG1 to SGn to the remote communication unit 40 through the wireless communication module 30 It is characterized in that it includes means.

The power transmission unit small group SG1 includes a plurality of input units 11 and circuit 12 connected in series to obtain a predetermined voltage,

Power having a standard resistor (not shown) connected to any one line of the circuit 12 to measure the voltage from the circuit 12 and measure the current, and a voltage measuring line proportional to the current from the standard resistor It is characterized in that it includes a small group of transmission units (SG1).

The power transmitting units 11 may be input to the circuit as different values of voltage, current, leakage current, etc. input from the power transmitting unit 11 .

The power measuring means 13 of the power transmitting unit small group SG1 periodically measures the voltage from the voltage and current measurement lines drawn from the circuit 12 of the power transmitting unit small group SG1 and A/D conversion,

A unique identification number is assigned, and the digitally converted current and voltage values and the unique identification number are transmitted to the control unit 20 according to a predetermined cycle, and converted into a power value by the calculation formula of the program inputted in the arithmetic unit and stored. means (13).

In addition, the control unit (microprocessor), the digital value corresponding to the A / D converted current and voltage from the power measuring means 13, a unique identification number, an interface (not shown) for receiving the amount of insolation from the insolation meter;

The digital voltage/current measurement value and the solar radiation measurement value of the unique identification number received from the interface are stored in a memory device, and a constant according to the characteristics and size of each power transmitter subgroups (SG1) to (SGn) is applied to the amount of power is corrected and calculated.

A key input unit for inputting the environment, the number of installations, calculation programs, etc. of the power transmission unit 11 of the small groups of power transmission units (SG1) to (SGn), an LCD monitor for displaying key input values and calculation processing results, and a program and a control unit 20 having a storage device for storing data.

Communication means, when the operation processing result of the control unit 20 is determined to be abnormal, the wireless module 30 for transmitting to the mobile communication terminal 40 of the administrator or user using WAP;

Through the wireless module 30 and the existing mobile communication network, the unique number of the power transmission unit small group 10 to the remote manager or user's mobile communication terminal 40 through the existing mobile communication network and the alarm text determined in response to the abnormal state and stored in the storage device By transmitting the measurement data to a remote manager or user, it is possible to know from a remote location which power transmitter subgroup 10 is in an abnormal state.

Briefly describing the active operation of such a remote monitoring system, the remote monitoring

When a desired administrator or user drives an application program installed in the mobile communication terminal to access the control unit 20 and transmits a status check request to the control unit 20, the control unit 20 receives a status check request from the manager or user It transmits the present or past results extracted by the user to the mobile communication terminal of the administrator or user.

In this embodiment, remote monitoring is performed without additional equipment by using WAP (Wireless Application Protocol) that is installed in the control unit 20 and the manager or user's mobile communication terminal and enables wireless data communication between the two devices. can do.

WAP acts as a communication emulator, and according to a predetermined protocol, it converts the received and demodulated signal from the other party into meaningful information. allows you to monitor

10 circuit 20 relay
30: parallel MUX selection circuit 30a: output unit
40: parallel MUX selection switch 50: second parallel MUX selection circuit
100: control unit 130: measurement unit
140: detection unit a': diode

Claims (1)

In a photovoltaic device capable of opening and closing DC high voltage with a field effect transistor parallel MUX switch,
The electric power flowing through the plurality of DC circuits 10 is collected into one circuit and converted into a system.
Configure the circuit to output,

A relay 20 for turning on/off circuits is connected to the plurality of DC circuits 10, and a relay 20a connected to any one circuit 10a among the plurality of circuits 10 is selected as a parallel MUX The parallel MUX selection circuit 30 is connected, but the parallel MUX selection switch 40 turns on/off according to the control signal of the control unit 100 to the parallel MUX selection circuit 30;

Connecting the input short circuit prevention diode (a') to the input part (30a) of the parallel MUX selection circuit (30) to which the current is input to the parallel MUX selection switch (40);

One side 50a of the second parallel MUX selection circuit 50 is respectively connected to the plurality of circuits 10 except for the circuit 10a connecting the parallel MUX selection circuit 30 and the parallel MUX selection switch 40. do
The other side 50b of the second parallel MUX selection circuit 50 is combined into one parallel MUX selection circuit corresponding to between the output part 30a of the parallel MUX selection circuit 30 and the diode a' ( 30) is connected to output power,
A diode (a) connected to each of the plurality of second parallel MUX selection circuits 50 to prevent an input short circuit, and a measuring unit 130 for monitoring the state of the flowing power value of the circuit;
In a state in which the plurality of relays 20 and the parallel MUX selection switch 40 connected to the plurality of circuits 10 according to the control signal of the control unit 100 are kept in the on' state,
In the process of sequentially turning on/off a plurality of relays 20 for a set time through the control unit 100, the power passing through the parallel MUX selection switch 40 is measured through the detection unit 140,

When the measured value measured in one circuit is out of the preset voltage range, it is determined that there is a problem in the circuit 10 out of the voltage range, and
A photovoltaic device capable of opening and closing DC high voltage with a field effect transistor parallel MUX selection switch, characterized in that the relay 20 is turned off to cut off the power.

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