阅读说明：本技术 一种智能配电箱及其控制方法和系统 (Intelligent distribution box and control method and system thereof ) 是由 翟富生 周宁 曹莹 李秀美 李勇 于 2021-07-06 设计创作，主要内容包括：本发明公开了一种智能配电箱及其控制方法和系统,智能配电箱包括配电箱外壳内部的第一、第二及第三智能断路器、串联补偿电容模块、逆变器、数据采集器及控制器；第一智能断路器连接储能电池和/或光伏发电单元；第二智能断路器连接交流电网；第三智能断路器连接负载；第一智能断路器的第二端与逆变器串联形成第一支路,第二智能断路器的第二端与串联补偿电容模块串联形成第二支路,第一支路、述第二支路及第三智能断路器并联连接；数据采集器用于采集智能配电箱的电路参数；控制器用于根据电路参数及预设电压对智能配电箱进行控制。本发明实施减少低压配电网中负载出现低电压的问题,提高功率因数,可广泛应用于电力系统。(The invention discloses an intelligent distribution box and a control method and a system thereof, wherein the intelligent distribution box comprises a first intelligent circuit breaker, a second intelligent circuit breaker, a third intelligent circuit breaker, a series compensation capacitor module, an inverter, a data collector and a controller which are arranged inside a distribution box shell; the first intelligent circuit breaker is connected with the energy storage battery and/or the photovoltaic power generation unit; the second intelligent circuit breaker is connected with an alternating current power grid; the third intelligent circuit breaker is connected with a load; the second end of the first intelligent circuit breaker is connected with the inverter in series to form a first branch circuit, the second end of the second intelligent circuit breaker is connected with the series compensation capacitor module in series to form a second branch circuit, and the first branch circuit, the second branch circuit and the third intelligent circuit breaker are connected in parallel; the data acquisition unit is used for acquiring circuit parameters of the intelligent distribution box; the controller is used for controlling the intelligent distribution box according to the circuit parameters and the preset voltage. The invention reduces the problem of low voltage of the load in the low-voltage distribution network, improves the power factor and can be widely applied to the power system.)

1. An intelligent distribution box is characterized by comprising a distribution box shell, a first intelligent circuit breaker, a second intelligent circuit breaker, a third intelligent circuit breaker, a series compensation capacitor module, an inverter, a data collector and a controller, wherein the first intelligent circuit breaker, the second intelligent circuit breaker and the third intelligent circuit breaker are arranged in the distribution box shell;

the first end of the first intelligent circuit breaker is used for being connected with an energy storage battery and/or a photovoltaic power generation unit;

the first end of the second intelligent circuit breaker is used for connecting an alternating current power grid;

the first end of the third intelligent circuit breaker is used for connecting a load;

the second end of the first intelligent circuit breaker is connected with the inverter in series to form a first branch circuit, the second end of the second intelligent circuit breaker is connected with the series compensation capacitor module in series to form a second branch circuit, and the first branch circuit, the second branch circuit and the third intelligent circuit breaker are connected in parallel;

the series compensation capacitor module comprises a fourth intelligent circuit breaker, an alternating current capacitor unit and an inductance unit which are connected in parallel;

the data acquisition unit is used for acquiring circuit parameters of the first intelligent circuit breaker, the second intelligent circuit breaker, the third intelligent circuit breaker, the inverter and the series compensation capacitor module; the circuit parameters include voltage and current;

the controller is used for controlling the intelligent distribution box according to the circuit parameters and the preset voltage.

2. The intelligent power distribution box according to claim 1, wherein the inductance unit comprises an inductor, a first thyristor and a second thyristor, and the first thyristor and the second thyristor are connected in series with the inductor after being connected in parallel in an inverse direction.

3. The intelligent power distribution box of claim 1, wherein said ac capacitive unit comprises a plurality of capacitors connected in parallel.

4. The intelligent power distribution box according to claim 3, wherein the AC capacitor unit comprises a first capacitor, a second capacitor, a third capacitor and a fourth capacitor connected in parallel, the second capacitor has a capacitance value twice that of the first capacitor, the third capacitor has a capacitance value four times that of the first capacitor, and the fourth capacitor has a capacitance value eight times that of the first capacitor.

5. An intelligent distribution box system, comprising an intelligent terminal and the intelligent distribution box of any one of claims 1 to 4, wherein the intelligent terminal is in wireless communication with the intelligent distribution box, and the intelligent terminal is used for displaying the circuit parameters and the voltage of the third intelligent circuit breaker.

6. A control method of an intelligent distribution box is characterized by being applied to the intelligent distribution box of any one of claims 1-4, and comprising the following steps:

when the acquired voltage of the third intelligent circuit breaker is greater than or equal to a preset voltage, the controller controls the second intelligent circuit breaker, the third intelligent circuit breaker and the fourth intelligent circuit breaker to be closed and controls the first intelligent circuit breaker to be opened;

when the acquired voltage of the third intelligent circuit breaker is smaller than a preset voltage, the controller controls the second intelligent circuit breaker and the third intelligent circuit breaker to be closed and controls the fourth intelligent circuit breaker to be opened; when the voltage of the third intelligent circuit breaker collected again is larger than or equal to the preset voltage, the first intelligent circuit breaker is controlled to be switched off; otherwise, controlling the first intelligent circuit breaker to be closed.

7. The intelligent distribution box control method according to claim 6, applied to the intelligent distribution box of claim 2, further comprising the steps of:

and when the fourth intelligent circuit breaker is in a disconnected state, controlling the positive voltage conduction time of the first thyristor and the negative voltage conduction time of the second thyristor.

8. The control method of the smart distribution box according to claim 6, applied to the smart distribution box according to claim 3, further comprising:

and when the fourth intelligent circuit breaker is in an off state, controlling the conduction number of the alternating current capacitor units.

Technical Field

The invention relates to a power system, in particular to an intelligent distribution box and a control method and system thereof.

Background

In low voltage distribution networks, line losses and voltage drops increase with increasing power transmission distance, which causes a phenomenon that the voltage at the customer premises far from the distribution transformer is too low, called low voltage. Low voltage problems occur primarily at the end of the distribution substation area and in remote areas; in addition, when the distribution line is in a low power factor state, the low voltage problem is also easily caused.

Disclosure of Invention

In view of this, an object of the embodiments of the present invention is to provide an intelligent distribution box, and a control method and a control system thereof, which reduce the problem of low voltage appearing in a load in a low-voltage distribution network and improve a power factor.

In a first aspect, an embodiment of the present invention provides an intelligent distribution box, including a distribution box housing, and a first intelligent circuit breaker, a second intelligent circuit breaker, a third intelligent circuit breaker, a series compensation capacitor module, an inverter, a data collector, and a controller inside the distribution box housing;

the first end of the first intelligent circuit breaker is used for being connected with an energy storage battery and/or a photovoltaic power generation unit;

the first end of the second intelligent circuit breaker is used for connecting an alternating current power grid;

the first end of the third intelligent circuit breaker is used for connecting a load;

the second end of the first intelligent circuit breaker is connected with the inverter in series to form a first branch circuit, the second end of the second intelligent circuit breaker is connected with the series compensation capacitor module in series to form a second branch circuit, and the first branch circuit, the second branch circuit and the third intelligent circuit breaker are connected in parallel;

the series compensation capacitor module comprises a fourth intelligent circuit breaker, an alternating current capacitor unit and an inductance unit which are connected in parallel;

the data acquisition unit is used for acquiring circuit parameters of the first intelligent circuit breaker, the second intelligent circuit breaker, the third intelligent circuit breaker, the inverter and the series compensation capacitor module; the circuit parameters include voltage and current;

the controller is used for controlling the intelligent distribution box according to the circuit parameters and the preset voltage.

Optionally, the inductance unit includes an inductance, a first thyristor and a second thyristor, and the first thyristor and the second thyristor are connected in parallel in an inverse direction and then connected in series with the inductance.

Optionally, the alternating current capacitance unit includes a plurality of capacitors connected in parallel.

Optionally, the alternating current capacitance unit includes a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor connected in parallel, where a capacitance value of the second capacitor is twice a capacitance value of the first capacitor, a capacitance value of the third capacitor is four times a capacitance value of the first capacitor, and a capacitance value of the fourth capacitor is eight times a capacitance value of the first capacitor.

In a second aspect, an embodiment of the present invention provides an intelligent distribution box system, which includes an intelligent terminal and the intelligent distribution box described in the embodiment of the first aspect, wherein the intelligent terminal is in wireless communication with the intelligent distribution box, and the intelligent terminal is configured to display the circuit parameter and the voltage of the third intelligent circuit breaker.

In a third aspect, an embodiment of the present invention provides a method for controlling an intelligent distribution box, which is applied to the intelligent distribution box described in the embodiment of the first aspect, and includes the steps of:

when the acquired voltage of the third intelligent circuit breaker is greater than or equal to a preset voltage, the controller controls the second intelligent circuit breaker, the third intelligent circuit breaker and the fourth intelligent circuit breaker to be closed and controls the first intelligent circuit breaker to be opened;

when the acquired voltage of the third intelligent circuit breaker is smaller than a preset voltage, the controller controls the second intelligent circuit breaker and the third intelligent circuit breaker to be closed and controls the fourth intelligent circuit breaker to be opened; when the voltage of the third intelligent circuit breaker collected again is larger than or equal to the preset voltage, the first intelligent circuit breaker is controlled to be switched off; otherwise, controlling the first intelligent circuit breaker to be closed.

Optionally, the control method of the intelligent distribution box further includes the steps of:

and when the fourth intelligent circuit breaker is in a disconnected state, controlling the positive voltage conduction time of the first thyristor and the negative voltage conduction time of the second thyristor.

Optionally, the control method of the intelligent distribution box further includes:

and when the fourth intelligent circuit breaker is in an off state, controlling the conduction number of the alternating current capacitor units.

The implementation of the embodiment of the invention has the following beneficial effects: in the embodiment of the invention, a first intelligent circuit breaker is connected with an inverter in series to form a first branch circuit, a second intelligent circuit breaker is connected with a series compensation capacitor module in series to form a second branch circuit, the first branch circuit and the second branch circuit are connected in parallel and then connected with a third intelligent circuit breaker connected with a load in series, and the first branch circuit and the second branch circuit are used for adjusting according to the voltage of the load, so that the problem of low voltage of the load in a low-voltage distribution network is solved; in addition, the series compensation capacitor module comprises an alternating current capacitor unit and an inductance unit, and the power factor is improved by adjusting the alternating current capacitor unit and the inductance unit.

Drawings

Fig. 1 is a block diagram of an intelligent distribution box according to an embodiment of the present invention;

fig. 2 is a circuit diagram of a series compensation capacitor module according to an embodiment of the present invention;

fig. 3 is a schematic flowchart illustrating steps of a control method for an intelligent distribution box according to an embodiment of the present invention;

fig. 4 is a graph of the relationship between current and voltage of an intelligent distribution box provided by the embodiment of the invention.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments. The step numbers in the following embodiments are provided only for convenience of illustration, the order between the steps is not limited at all, and the execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

As shown in fig. 1, an embodiment of the present invention provides an intelligent distribution box, which includes a distribution box housing, and a first intelligent circuit breaker CB1, a second intelligent circuit breaker CB2, a third intelligent circuit breaker CB3, a series compensation capacitor module SCC, an inverter DC/AC, a data collector, and a controller inside the distribution box housing;

the first end of the first intelligent circuit breaker CB1 is used for connecting an energy storage battery and/or a photovoltaic power generation unit;

the first end of the second intelligent circuit breaker CB2 is used for connecting an alternating current power grid;

the first end of the third intelligent circuit breaker CB3 is used for connecting a load;

a second end of the first intelligent circuit breaker CB1 is connected with the inverter in series to form a first branch circuit, a second end of the second intelligent circuit breaker CB2 is connected with the series compensation capacitor module in series to form a second branch circuit, and the first branch circuit, the second branch circuit and the third intelligent circuit breaker CB3 are connected in parallel;

the series compensation capacitor module comprises a fourth intelligent circuit breaker, an alternating current capacitor unit and an inductance unit which are connected in parallel;

the data acquisition unit is used for acquiring circuit parameters of the first intelligent circuit breaker, the second intelligent circuit breaker, the third intelligent circuit breaker, the inverter and the series compensation capacitor module; the circuit parameters include voltage and current;

the controller is used for controlling the intelligent distribution box according to the circuit parameters and the preset voltage.

It should be noted that the data collector sends the collected voltage and current data of CB1, CB2, CB3, DC/AC and SCC to the controller, and the controller controls CB1, CB2, CB3, DC/AC and SCC according to a preset numerical range. For example, when the voltage on the CB3 has low voltage (the voltage is lower than 60% of the rated voltage), the CB4 is disconnected, and the series compensation capacitor is connected into the circuit for first voltage compensation; if the voltage on the CB3 still does not reach the rated voltage, the CB1 is closed, and the current on the CB3 is compensated for the second time so as to ensure that the load can obtain enough rated power. In the compensation process, the voltage and the current are monitored and analyzed in real time.

It can be understood by those skilled in the art that the preset voltage is set according to specific requirements, and the embodiments of the present invention are not particularly limited.

The first end of the first intelligent circuit breaker CB1 is connected to either the energy storage battery or the photovoltaic power generation unit, or both. The photovoltaic power generation unit is connected, so that photovoltaic electric energy can be fully utilized, and the reliability of load power supply and the electric energy quality can be improved.

Optionally, the inductance unit includes an inductance, a first thyristor and a second thyristor, and the first thyristor and the second thyristor are connected in parallel in an inverse direction and then connected in series with the inductance.

Specifically, as shown in fig. 2, the series compensation capacitor module includes a fourth intelligent circuit breaker CB4, an ac capacitor unit C, and an inductor unit connected in parallel, where the inductor unit includes an inductor L, a first thyristor T1, and a second thyristor T2, and the first thyristor T1 and the second thyristor T2 are connected in series with the inductor L after being connected in parallel in an inverse direction.

Optionally, the alternating current capacitance unit includes a plurality of capacitors connected in parallel.

Optionally, the alternating current capacitance unit includes a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor connected in parallel, where a capacitance value of the second capacitor is twice a capacitance value of the first capacitor, a capacitance value of the third capacitor is four times a capacitance value of the first capacitor, and a capacitance value of the fourth capacitor is eight times a capacitance value of the first capacitor.

Specifically, the capacitance value required by the circuit is adjusted according to the requirement, and the more the capacitors are connected in parallel with the alternating current capacitor unit, the larger the adjustment range of the capacitance value is. If the alternating current capacitor unit comprises a first capacitor, a second capacitor, a third capacitor and a fourth capacitor which are connected in parallel, the capacitance value of the second capacitor is twice that of the first capacitor, the capacitance value of the third capacitor is four times that of the first capacitor, and the capacitance value of the fourth capacitor is eight times that of the first capacitor, then the capacitance values of the access circuits can be any integral multiple of the first capacitors in the range of 0-15 respectively.

The implementation of the embodiment of the invention has the following beneficial effects: in the embodiment of the invention, a first intelligent circuit breaker is connected with an inverter in series to form a first branch circuit, a second intelligent circuit breaker is connected with a series compensation capacitor module in series to form a second branch circuit, the first branch circuit and the second branch circuit are connected in parallel and then connected with a third intelligent circuit breaker connected with a load in series, and the first branch circuit and the second branch circuit are used for adjusting according to the voltage of the load, so that the problem of low voltage of the load in a low-voltage distribution network is solved; in addition, the series compensation capacitor module comprises an alternating current capacitor unit and an inductance unit, and the power factor is improved by adjusting the alternating current capacitor unit and the inductance unit.

The embodiment of the invention also provides an intelligent distribution box system which comprises an intelligent terminal and the intelligent distribution box in the embodiment of the first aspect, wherein the intelligent terminal is in wireless communication with the intelligent distribution box and is used for displaying the circuit parameters and the voltage of the third intelligent circuit breaker.

It should be noted that the intelligent terminal may be a mobile phone, a tablet, a desktop computer, a notebook computer, or the like, the intelligent distribution box may generate a corresponding two-dimensional code, and the intelligent terminal may associate the corresponding intelligent distribution box by scanning the two-dimensional code. The intelligent terminal can download corresponding APP software, voltage and current data on the five modules of CB1, CB2, CB3, DC/AC and SCC can be checked on APP, and whether a low-voltage problem prompt exists in the current CB3 or not can be checked, so that a user can visually and safely check the states of power supply and operation.

The implementation of the embodiment of the invention has the following beneficial effects: in the embodiment of the invention, a first intelligent circuit breaker is connected with an inverter in series to form a first branch circuit, a second intelligent circuit breaker is connected with a series compensation capacitor module in series to form a second branch circuit, the first branch circuit and the second branch circuit are connected in parallel and then connected with a third intelligent circuit breaker connected with a load in series, and the first branch circuit and the second branch circuit are used for adjusting according to the voltage of the load, so that the problem of low voltage of the load in a low-voltage distribution network is solved; in addition, the series compensation capacitor module comprises an alternating current capacitor unit and an inductance unit, and the power factor is improved by adjusting the alternating current capacitor unit and the inductance unit.

As shown in fig. 3, an embodiment of the present invention provides a method for controlling an intelligent distribution box, which is applied to the intelligent distribution box, and includes the steps of:

s1, when the collected voltage of the third intelligent circuit breaker is larger than or equal to a preset voltage, the controller controls the second intelligent circuit breaker, the third intelligent circuit breaker and the fourth intelligent circuit breaker to be closed and controls the first intelligent circuit breaker to be opened;

s2, when the collected voltage of the third intelligent circuit breaker is smaller than a preset voltage, the controller controls the second intelligent circuit breaker and the third intelligent circuit breaker to be closed and controls the fourth intelligent circuit breaker to be opened; when the voltage of the third intelligent circuit breaker collected again is larger than or equal to the preset voltage, the first intelligent circuit breaker is controlled to be switched off; otherwise, controlling the first intelligent circuit breaker to be closed.

In particular, as shown in figure 4,which represents the phasor of the grid voltage,representing the phasor of the series capacitance compensator voltage,to represent the load voltage phasor,representing the phasor of the current of the grid,in order to series-connect the current phasors of the capacitive compensator,is the load current phasor. First, when the CB2/CB3/CB4 circuit breaker is closed, and CB1 is open, the load is powered directly from the grid,if the power grid has low voltage, the load has the problem of low voltage and cannot work normally. Then, the circuit breaker CB4 is opened, the compensation capacitor is connected in series with the power grid to supply power to the load, and at the momentBy controlling T1 and T2, the compensator voltage phasor and the grid voltage phasor are kept in a vertical relation, according to the long-edge-to-large-angle relation of the characteristics of a right triangle, the angle corresponding to the load voltage is a right angle, and the angle corresponding to the power voltage is an acute angle, so that the actually obtained module value of the load voltage phasor is greater than the module value of the grid voltage, and the problem of low load voltage is solved. Finally, since the normal operation of the load not only needs to satisfy the voltage condition, but also needs to reach the rated power, the compensation in B does not necessarily ensure that the load can work normally, and at the moment, the CB1 needs to be closed to compensate the current of the load, so that the current of the load is compensatedThe amplification of the load current is realized to ensure that the load reaches the rated power and operates normally.

Optionally, the control method of the intelligent distribution box further includes the steps of:

and when the fourth intelligent circuit breaker is in a disconnected state, controlling the positive voltage conduction time of the first thyristor and the negative voltage conduction time of the second thyristor.

Specifically, in connection with fig. 2, when CB4 is open, the equivalent capacitance of the series compensator SCC is:

in the formula, C is the capacitance value of the capacitor; l is the size of the inductor; omega is the angular frequency of the sine voltage waveform, and when the frequency is 50Hz, omega is 314 radian/second for the household electricity with the effective value of 220 volts; the k value is the control effect quantity of T1 and T2, and the adjustment of k enables Ceq to be changed within the range of 0.7-1.0 time of the C value. The T1 and the T2 are thyristors and are driven to be conducted in a phase control mode, the T1 is conducted in a positive half cycle in consideration of a sine voltage period, and current flows through the T1 from left to right through the L; t2 is turned on in the negative half cycle, and current flows from right to left through L through T2; when T1 is triggered to conduct at an angle of alpha in the positive half cycle phase, T2 is triggered to conduct at an angle of pi + alpha. By varying the magnitude of alpha, i.e. the value of k can be adjusted, thereby varying C_eq。

Optionally, the control method of the intelligent distribution box further includes:

and when the fourth intelligent circuit breaker is in an off state, controlling the conduction number of the alternating current capacitor units.

Specifically, the capacitance value required by the circuit is adjusted according to the requirement, and the more the capacitors are connected in parallel with the alternating current capacitor unit, the larger the adjustment range of the capacitance value is. If the alternating current capacitor unit comprises a first capacitor, a second capacitor, a third capacitor and a fourth capacitor which are connected in parallel, the capacitance value of the second capacitor is twice that of the first capacitor, the capacitance value of the third capacitor is four times that of the first capacitor, and the capacitance value of the fourth capacitor is eight times that of the first capacitor, then the capacitance values of the access circuits can be any integral multiple of the first capacitors in the range of 0-15 respectively.

The implementation of the embodiment of the invention has the following beneficial effects: in the embodiment of the invention, a first intelligent circuit breaker is connected with an inverter in series to form a first branch circuit, a second intelligent circuit breaker is connected with a series compensation capacitor module in series to form a second branch circuit, the first branch circuit and the second branch circuit are connected in parallel and then connected with a third intelligent circuit breaker connected with a load in series, and the first branch circuit and the second branch circuit are used for adjusting according to the voltage of the load, so that the problem of low voltage of the load in a low-voltage distribution network is solved; in addition, the series compensation capacitor module comprises an alternating current capacitor unit and an inductance unit, and the power factor is improved by adjusting the alternating current capacitor unit and the inductance unit.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.