CN101847831B - A distribution cabinet - Google Patents

Abstract

The invention discloses a power distribution cabinet, which comprises an incoming line circuit breaker, a voltage stabilizing power saving module and a power distribution device; a power supply is connected to the input end of the incoming line circuit breaker, and the output end of the incoming line circuit breaker is connected to the The input terminal of the voltage stabilizing and power saving module, the output terminal of the voltage stabilizing and power saving module is connected to the input terminal of the power distribution device. The power distribution cabinet may further include a bypass unit, and the power supply is connected to the power distribution device through a voltage stabilizing power-saving module or a bypass unit through an incoming circuit breaker. Compared with the existing power distribution cabinets, the present invention has the functions of voltage stabilization and power saving. When in use, power saving adjustment can be performed according to the difference of power supply voltage and power consumption time period, and the power can be stabilized while completing power saving and power distribution. and purification, improve power supply efficiency, and better meet power distribution needs.

Description

A distribution cabinet

technical field

The invention relates to a power distribution cabinet for industrial electric power, in particular to a power distribution cabinet with voltage stabilizing and power saving functions.

Background technique

In the 21st century, the impact of energy shortage and environmental pollution on the sustainable development of human economy and society is becoming more and more serious. Although my country has a vast territory and rich resources, it is still a poor country in terms of energy, especially in terms of energy utilization. Due to the influence of capital, technology and energy prices, my country's energy utilization is much lower than that of developed countries. More than 90% of energy is lost and wasted in the process of mining, processing and conversion, storage and transportation, and terminal utilization, especially in the utilization of electric power and electric equipment. Although my country's electric power industry is developing rapidly, it still cannot meet the needs of economic development and people's living needs. Therefore, saving energy is an urgent task in the power industry. The state also attaches great importance to the management of energy conservation. In the "Eleventh Five-Year Plan", it proposed that the energy consumption per unit of GDP must be reduced by 20% in 2010, as the mandatory implementation of energy conservation indicators. The current industrial power distribution cabinets only have basic power transmission and distribution functions, but little consideration is given to saving electric energy, especially in the case of different power supply voltages and power consumption periods, the power distribution cabinets cannot be adjusted according to the working conditions .

Contents of the invention

Purpose of the invention: In order to overcome the disadvantage that the power distribution cabinet in the prior art only has a single power distribution function, the present invention provides a power distribution cabinet with voltage stabilizing and power saving functions, which integrates power distribution and power saving functions.

Technical solution: In order to achieve the above object, the technical solution adopted in the present invention is:

A power distribution cabinet with a voltage stabilizing and power saving function, comprising an incoming line circuit breaker, a voltage stabilizing and power saving module and a power distribution device; the power supply is connected to the input end of the incoming line circuit breaker, and the output of the incoming line circuit breaker The terminal is connected to the input terminal of the voltage stabilizing and power saving module, and the output terminal of the voltage stabilizing and power saving module is connected to the input terminal of the power distribution device.

The power supply is a three-phase power supply.

The voltage stabilizing and power saving module may be composed of a multi-ratio tapped isolation transformer, a bidirectional thyristor module and a voltage stabilizing and power saving intelligent control unit, and the bidirectional thyristor module may be composed of multiple bidirectional thyristors. The output end of the incoming circuit breaker is connected to the primary side of the isolation transformer; each phase of the secondary side of the isolation transformer has multiple taps according to different transformation ratios, and each secondary side tap is connected to a bidirectional thyristor One power pole of the two-way thyristor corresponding to the same phase is connected together as an output, and its output voltage and current can be sent to the voltage stabilizing and power-saving intelligent control unit through sampling feedback; the two-way thyristor The output terminal of the module is connected to the input terminal of the power distribution device; the control unit is connected to the control terminal of the bidirectional thyristor module, and provides a trigger signal to the bidirectional thyristor module.

Multiple taps on the secondary side of the multi-ratio tapped isolation transformer correspond to different ratios, and the corresponding transformer ratio can be selected by turning on the corresponding bidirectional thyristor, so that the output voltage can be stabilized at the set range, in order to achieve the function of voltage regulation and power saving.

The power distribution device is provided with a detection circuit to detect the output voltage and current in real time, and at the same time capture the zero-crossing of the input voltage. The input end of the control unit is connected to the output end of the detection circuit, and the control unit performs voltage stabilization and power saving control on the voltage stabilizing module according to the real-time detection signal of the detection circuit.

The voltage stabilizing and power saving module can use voltage and current double zero-cross switching technology to control the voltage stabilizing and switching of bidirectional thyristors, so as to realize the functions of voltage stabilizing and power saving. When the input voltage zero-crossing signal appears, it is judged whether it is necessary to switch the transformation ratio of the current triac module. If it is necessary to switch the current transformation ratio, the output current zero-crossing signal is detected. When the output current zero-crossing signal appears, the transformation ratio is performed. To switch, that is, to provide a trigger signal to the triac module that needs to be triggered. In this way, it can be ensured that after the input voltage crosses zero, the thyristor reduces the current to zero through freewheeling, which means that the thyristor has been turned off naturally.

The power distribution cabinet may further include a bypass unit, the bypass unit is connected in parallel with the voltage stabilizing and power-saving module, and the power supply is connected to the power distribution device through the voltage stabilizing and power-saving module or the bypass unit through the incoming circuit breaker. According to the real-time signal, the control unit can select the power supply to be connected to the power distribution device through the voltage-stabilizing power-saving module or the bypass unit.

The power distribution cabinet can also include a display and a man-machine interface, which can display the electrical parameters of each distribution line, including the voltage, current, power and power factor of each three-phase and single-phase, etc., through the man-machine interface. Communication, menu control or remote control of the power distribution cabinet, or automatic or manual voltage stabilization and power saving and power distribution operations as required. This is conducive to the management and deployment of power consumption, and the power consumption data can be directly obtained during the working process of the power distribution cabinet, so as to better realize power saving and power distribution management.

Beneficial effects: the power distribution cabinet with voltage stabilizing and power saving functions provided by the present invention has voltage stabilizing and power saving functions compared with existing power distribution cabinets. Harmonics and current discontinuity are avoided in the process, while power saving and power distribution are completed, power is stabilized and purified, power supply efficiency is improved, and power distribution needs are better met.

Description of drawings

Fig. 1 is a structural representation of the present invention;

FIG. 2 is a schematic structural diagram of a voltage stabilizing and power saving module;

Fig. 3 is a connection terminal diagram of the control unit microcontroller;

Figure 4 is a voltage zero-crossing detection circuit;

Figure 5 is a current zero-crossing detection circuit;

Fig. 6 is a current sampling conditioning circuit;

Fig. 7 is a driving circuit diagram of a single-chip microcomputer driving a thyristor.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, a power distribution cabinet with voltage stabilizing and power saving functions includes an incoming line circuit breaker, a voltage stabilizing and power saving module, a power distribution device, a bypass unit, a display and a man-machine interface. The three-phase power supply (phase A, phase B and phase C) is connected to the input end of the incoming line circuit breaker, and the output end of the incoming line circuit breaker is connected to the input end of the voltage stabilizing power saving module and the bypass The input end of the unit, the output end of the voltage stabilizing and power saving module and the output end of the bypass unit are connected to the input end of the power distribution device. The three-phase power is connected to the power distribution device through the incoming circuit breaker through the voltage stabilizing power-saving module or the bypass unit.

The display and the man-machine interface can display the electrical parameters of each power distribution line, including the voltage, current, power and power factor of each three-phase and single-phase, etc. The man-machine communication can be realized through the man-machine interface, and the power distribution cabinet Perform menu control or remote control, or perform automatic or manual voltage stabilization and power saving and power distribution operations as required. This is conducive to the management and deployment of power consumption, and the power consumption data can be directly obtained during the working process of the power distribution cabinet, so as to better realize power saving and power distribution management.

In the exemplary embodiment, the bypass unit is formed by a bypass contactor.

The voltage stabilizing and power saving module is composed of a multi-ratio tapped isolation transformer, a bidirectional thyristor module and a voltage stabilizing and power saving intelligent control unit, and the bidirectional thyristor module is composed of a plurality of bidirectional thyristors. As shown in Figure 2, the three-phase voltage A phase, B phase and C phase of the incoming circuit breaker are respectively connected to the primary side of the tapped isolation transformer with multiple transformation ratios, and each phase of the secondary side has multiple taps according to different transformation ratios In the figure, the taps corresponding to phase A are marked as a1~an, the taps corresponding to phase B are marked as b1~bn, and the taps corresponding to phase C are marked as c1~cn. Each secondary tap is connected to a bidirectional controllable One power pole of silicon, the other power pole of n bidirectional thyristors corresponding to taps a1~an are connected together and recorded as output terminal AO, and the other power pole of n bidirectional thyristors corresponding to taps b1~bn The poles connected together are recorded as the output terminal BO, and the other power poles of the n bidirectional thyristors corresponding to the taps c1~cn are connected together and recorded as the output terminal CO. The output voltage and current of AO, BO and CO are sent to the voltage stabilizing and power-saving intelligent control unit through sampling feedback; the output terminals of the triac module, that is, AO, BO and CO are connected to the input terminals of the power distribution device; The voltage stabilizing and power saving intelligent control unit is connected to the control terminal of the bidirectional thyristor module, and provides a trigger signal to the bidirectional thyristor module.

The multiple taps on the secondary side of the multi-ratio tapped isolation transformer correspond to different ratios. In this embodiment, different ratios correspond to different gears. The larger the ratio, the higher the gear, and the output voltage is also higher. The larger it is, the corresponding transformer ratio can be selected by turning on the corresponding triac, so that the output voltage can be stabilized within the set range, so as to achieve the function of voltage stabilization and power saving.

The power distribution device is provided with a detection circuit to detect the output voltage and current in real time, and at the same time capture the zero-crossing of the input voltage. The input terminal of the voltage stabilizing and power saving intelligent control unit is connected to the output terminal of the detection circuit, and the voltage stabilizing and power saving intelligent control unit performs voltage stabilization and power saving control on the voltage stabilizing module according to the real-time detection signal of the detection circuit, or Direct selection of bypass units for power distribution.

The voltage stabilizing and power saving module can use voltage and current double zero-cross switching technology to control the voltage stabilizing and switching of bidirectional thyristors, so as to realize the functions of voltage stabilizing and power saving. When the zero-crossing signal of the three-phase input voltage appears, judge whether it is necessary to switch the gear of the current bidirectional thyristor: if it is judged that there is no need to shift gears, it means that the thyristor that was turned on in the previous cycle will continue to be turned on, and the power can be saved through voltage regulation The control unit provides a conduction trigger signal to conduct the corresponding bidirectional thyristor, so that the triac zero-crossing triggers; if it is judged that it is necessary to shift gears, it must first detect the current output current with a zero-crossing signal (the conduction trigger cannot be provided directly The switching triac required for signal conduction, because the characteristics of the thyristor itself is naturally turned off, if the previously conducting triac is not turned off before the newly conducting triac is turned on If it is broken, it will cause a short circuit on the secondary side of the transformer.), when the output current zero-crossing signal appears, the ratio switching is performed, that is, a trigger signal is provided to the bidirectional thyristor module that needs to be triggered. In this way, it can be ensured that after the input voltage crosses zero, the thyristor reduces the current to zero through freewheeling, which means that the thyristor has been turned off naturally.

The voltage stabilizing and power saving intelligent control unit can take the single-chip microcomputer as shown in FIG. 3 as the core to complete the control of the voltage stabilizing and power saving module.

Figure 4 is the voltage zero-crossing detection circuit, UA is the phase A voltage sampling signal, through the voltage zero-crossing detection circuit, the voltage zero-crossing signal of UA_Z is obtained, and the voltage zero-crossing signal is sent to the single-chip microcomputer of the control unit shown in Figure 3 .

Figure 5 is the current zero-crossing detection circuit, IA is the A-phase current sampling signal, through the current zero-crossing detection circuit, first inverting and amplifying, and then comparing the current zero-crossing signal of IA_Z, the current zero-crossing signal is sent to the current zero-crossing signal shown in Figure 3 In the microcontroller of the control unit. The current zero-crossing detection circuits of phase B and phase C are the same as those of phase A.

Figure 6 shows the current conditioning circuit, IA is the phase A current sampling signal, the analog signal IAC_AD with an amplitude of 0-3.3V can be obtained through the current sampling and conditioning circuit and sent to the single-chip microcomputer of the control unit shown in Figure 3 for analog/digital convert. The current sampling and conditioning circuits of phase B and phase C are the same as those of phase A.

Fig. 7 is a driving circuit diagram of the SCR driven by the single-chip microcomputer of the control unit, and the signal of the single-chip microcomputer triggers the corresponding SCR through the driving circuit. As shown in Figure 7, the SCM control enable signal CTR_EN from the control unit drives the transistor BC337 to provide power to the optocoupler TLP3052, and RB2' is connected to the lower end of R2, which is the drive control signal sent by the MCU, through which the optocoupler U3 and When U4 is turned on and off, when the optocoupler U3 and U4 are connected, the internal bidirectional thyristor is turned on. If there is a voltage between the connection terminal B2 and LOADB at this time, B2G2 makes the bidirectional thyristor in SK2 turn on. Realize the drive of the control unit to the thyristor.

The voltage-stabilizing and power-saving module can perform voltage-stabilizing and power-saving operation in the following four working modes:

(1) Time + voltage control: the power distribution cabinet starts and shuts down at regular intervals every day and automatically adjusts gears to control operation according to the voltage required for voltage stabilization and power saving;

(2) Time forced gear position control: the power distribution cabinet starts and shuts down regularly every day and runs in a fixed gear;

(3) 24-hour voltage control: the power distribution cabinet automatically adjusts the gear position according to the voltage required for voltage stabilization and power saving to control continuous and uninterrupted operation;

(4) 24-hour mandatory gear position control: the power distribution cabinet is always kept in a fixed gear position.

During the working process of the voltage-stabilizing and power-saving module, the three-phase output voltage detection signal enters the voltage-stabilizing and power-saving intelligent control unit after conditioning, filtering and analog/digital conversion, and the single-chip computer of the voltage-stabilizing and power-saving intelligent control unit calculates the three-phase voltage Obtain the effective value and calculate the average value of the slip for 5 seconds. At the same time, calculate the voltage value of each gear according to the different transformation ratios of the transformer, judge and operate the gear according to the corresponding working mode, and turn on the two-way adjustable SCR.

The incoming line circuit breaker adopts a circuit breaker or miniature circuit breaker (ie air switch), and the power distribution device also adopts a miniature circuit breaker to distribute power to the electric load.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (2)

1. A power distribution cabinet, the power distribution cabinet includes an incoming circuit breaker, a voltage stabilizing power-saving module, a power distribution device and a bypass unit, characterized in that: The power supply is connected to the input end of the incoming line circuit breaker, the output end of the incoming line circuit breaker is connected to the input end of the voltage stabilizing and power saving module, and the output end of the voltage stabilizing and power saving module is connected to the power distribution device the input terminal; The voltage stabilizing and power saving module is composed of a multi-ratio tapped isolation transformer, a bidirectional thyristor module and a voltage stabilizing and power saving intelligent control unit, and the bidirectional thyristor module is composed of a plurality of bidirectional thyristors. The output terminal of the incoming circuit breaker is connected to the primary side of the isolation transformer, the secondary side of the isolation transformer is connected to the input terminal of the triac module, and the voltage stabilizing and power saving intelligent control unit is connected to the triac The control terminal of the module, the output terminal of the triac module is connected to the input terminal of the power distribution device; The output end of the incoming circuit breaker is also connected to the input end of the bypass unit, and the output end of the voltage stabilizing and energy-saving module is also connected to the output end of the bypass unit, so that the bypass unit and the Voltage stabilizing and power saving modules connected in parallel; The power distribution device is provided with a detection circuit for real-time detection of the output voltage and output current, the input end of the voltage stabilizing and power saving intelligent control unit is connected to the output end of the detection circuit; the voltage stabilizing and power saving intelligent control unit The voltage and current double zero-crossing switching technology is used to control the voltage regulation and switching of the bidirectional thyristor module; The output voltage and output current are sent to the voltage-stabilizing and power-saving intelligent control unit through sampling feedback, and the voltage-stabilizing and power-saving intelligent control unit performs voltage stabilization and power-saving on the voltage-stabilizing and power-saving module according to the above-mentioned voltage and current signals detected in real time by the detection circuit. Power-saving control, or directly select the bypass unit for control. 2. The power distribution cabinet according to claim 1, characterized in that: the power distribution cabinet further includes a display and a man-machine interface.

Images