CN201528205U - Low-voltage intelligent reactive power compensation device - Google Patents
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Abstract
Description
技术领域technical field
本实用新型涉及一种低压智能无功补偿装置。The utility model relates to a low-voltage intelligent reactive power compensation device.
背景技术Background technique
在交流电路中,由电源供给负载的电功率有两种;一种是有功功率,一种是无功功率。有功功率是保持用电设备正常运行所需的电功率,是将电能转换为其他形式能量(机械能、光能、热能)的电功率。在正常情况下,用电设备不但要从电源取得有功功率,同时还需要从电源取得无功功率。如果电网中的无功功率供不应求,用电设备就没有足够的无功功率来建立正常的电磁场,这些用电设备就不能维持在额定情况下工作,用电设备的端电压就要下降,从而影响用电设备的正常运行。低压配电网无功补偿的方法提高功率因数的主要方法是采用低压无功补偿技术,我们通常采用的方法主要有两种:随机补偿、随器补偿。随机补偿就是将低压电容器组与电动机并接,通过控制、保护装置与电机同时投切。随机补偿适用于补偿电动机的无功消耗,以补励磁无功为主,此种方式可较好地限制用电单位无功负荷。随器补偿是指将低压电容器通过低压保险接在配电变压器二次侧,以补偿配电变压器空载无功的补偿方式。配变在轻载或空载时的无功负荷主要是变压器的空载励磁无功,配变空载无功是用电单位无功负荷的主要部分,对于轻负载的配变而言,这部分损耗占供电量的比例很大,从而导致电费单价的增加跟踪补偿是指以无功补偿投切装置作为控制保护装置,将低压电容器组补偿在大用户0.4kv母线上的补偿方式。但是以上两种补偿方法不够灵活,不能智能化的配置补偿电容器组。In the AC circuit, there are two kinds of electric power supplied by the power supply to the load; one is active power and the other is reactive power. Active power is the electrical power required to maintain the normal operation of electrical equipment, and it is the electrical power that converts electrical energy into other forms of energy (mechanical energy, light energy, thermal energy). Under normal circumstances, electrical equipment not only needs to obtain active power from the power supply, but also needs to obtain reactive power from the power supply. If the reactive power in the power grid is in short supply, the electrical equipment will not have enough reactive power to establish a normal electromagnetic field, and these electrical equipment will not be able to work under rated conditions, and the terminal voltage of the electrical equipment will drop, thereby affecting Normal operation of electrical equipment. Low-voltage distribution network reactive power compensation method The main method to improve power factor is to use low-voltage reactive power compensation technology. There are two main methods we usually use: random compensation and follower compensation. Random compensation is to connect the low-voltage capacitor bank and the motor in parallel, and switch them simultaneously with the motor through the control and protection devices. The random compensation is suitable for compensating the reactive power consumption of the motor, mainly to supplement the excitation reactive power. This method can better limit the reactive power load of the power consumption unit. Follower compensation refers to the compensation method that connects the low-voltage capacitor to the secondary side of the distribution transformer through the low-voltage fuse to compensate the no-load reactive power of the distribution transformer. The reactive load of the distribution transformer at light load or no-load is mainly the no-load excitation reactive power of the transformer, and the no-load reactive power of the distribution transformer is the main part of the reactive load of the power unit. For the distribution transformer with light load, this Partial losses account for a large proportion of power supply, which leads to an increase in the unit price of electricity. Tracking compensation refers to the compensation method that uses reactive power compensation switching devices as control and protection devices, and compensates low-voltage capacitor banks on the 0.4kv busbar of large users. However, the above two compensation methods are not flexible enough to intelligently configure the compensation capacitor bank.
实用新型内容Utility model content
本实用新型所要解决的技术方案是针对上述现有技术的不足,提供一种低压智能无功补偿装置。The technical solution to be solved by the utility model is to provide a low-voltage intelligent reactive power compensation device for the above-mentioned deficiencies in the prior art.
为解决上述技术问题,本实用新型采用的技术方案为:一种低压智能无功补偿装置,包括单片机、电流电压检测电路、电流电压互感器、复合开关及其检测驱动电路和断路器;电流电压互感器的输出端连接电流电压检测电路,电流电压检测电路的输出端连接单片机,用以将检测到的系统三相线的电流信号和电压信号输送给单片机;断路器的输出端通过复合开关链接到电容器组,复合开关的检测驱动电路连接在复合开关和单片机之间。In order to solve the above technical problems, the technical solution adopted by the utility model is: a low-voltage intelligent reactive power compensation device, including a single-chip microcomputer, a current and voltage detection circuit, a current and voltage transformer, a composite switch and its detection drive circuit and a circuit breaker; The output end of the transformer is connected to the current and voltage detection circuit, and the output end of the current and voltage detection circuit is connected to the single-chip microcomputer to transmit the detected current signal and voltage signal of the three-phase line of the system to the single-chip microcomputer; the output end of the circuit breaker is connected through a composite switch To the capacitor bank, the detection driving circuit of the composite switch is connected between the composite switch and the single-chip microcomputer.
作为本实用新型进一步改进的技术方案,还包括分别与单片机连接的人机接口、存储器和通讯接口;人机接口显示单片机输出的系统参数同时设置系统参数给单片机,所设置的系统参数同时存储在存储器中。通讯接口用于将多个所述低压智能无功优化装置连接在一起。As a further improved technical solution of the utility model, it also includes a man-machine interface, a memory and a communication interface connected with the single-chip microcomputer respectively; the man-machine interface displays the system parameters output by the single-chip microcomputer and sets the system parameters to the single-chip microcomputer at the same time, and the set system parameters are simultaneously stored in the in memory. The communication interface is used to connect multiple low-voltage intelligent reactive power optimization devices together.
作为本实用新型进一步改进的技术方案,所述装置还设有温度传感器,温度传感器置于电容器组内,温度传感器的输出连接单片机。As a further improved technical solution of the utility model, the device is also provided with a temperature sensor, the temperature sensor is placed in the capacitor bank, and the output of the temperature sensor is connected to a single-chip microcomputer.
作为本实用新型进一步改进的技术方案,所述电流电压检测电路包括模拟开关、放大电路和整形电路,模拟开关有两路输出,一路连接放大电路后与单片机连接,另一路通过整形电路与单片机连接。As a further improved technical solution of the present invention, the current and voltage detection circuit includes an analog switch, an amplifying circuit and a shaping circuit. The analog switch has two outputs, one is connected to the amplifying circuit and then connected to the single-chip microcomputer, and the other is connected to the single-chip microcomputer through the shaping circuit. .
作为本实用新型进一步改进的技术方案,所述断路器的输出端还连接电抗器。As a further improved technical solution of the utility model, the output end of the circuit breaker is also connected to a reactor.
本实用新型采用单片机作为控制器,通过电流电压互感器和电流电压检测电路检测系统三相线的电流和电压,通过单片机精确计算无功因数,同时单片机控制复合开关实现过零投切;另外,本实用新型还设有人机接口和通讯接口,通过人机接口能够输入和设置系统参数。本实用新型实现了低压无功补偿的智能化控制和无涌流、无电弧投切,实现感性功率和容性功率的全面合理优化,使用灵活方便,无功补偿效率高。The utility model adopts a single-chip microcomputer as a controller, detects the current and voltage of the three-phase line of the system through the current-voltage transformer and the current-voltage detection circuit, and accurately calculates the reactive power factor through the single-chip microcomputer, and at the same time, the single-chip microcomputer controls the composite switch to realize zero-crossing switching; in addition, The utility model is also provided with a man-machine interface and a communication interface, through which system parameters can be input and set. The utility model realizes intelligent control of low-voltage reactive power compensation, no inrush current and no arc switching, comprehensive and reasonable optimization of inductive power and capacitive power, flexible and convenient use, and high reactive power compensation efficiency.
附图说明Description of drawings
图1为本实用新型的系统结构示意图。Fig. 1 is a schematic diagram of the system structure of the present utility model.
图2为本实用新型的正弦波-方波整形电路图。Fig. 2 is the sine wave-square wave shaping circuit diagram of the utility model.
图3为本实用新型的放大电路图。Fig. 3 is the enlarged circuit diagram of the utility model.
图4为本实用新型的单片机与正弦波-方波整形电路和放大电路的连接示意图。Fig. 4 is a schematic diagram of the connection between the single-chip microcomputer of the present invention, the sine wave-square wave shaping circuit and the amplifier circuit.
图5为多台低压智能无功补偿装置通过通讯接口相连接的示意图。Fig. 5 is a schematic diagram of multiple low-voltage intelligent reactive power compensation devices connected through communication interfaces.
具体实施方式Detailed ways
下面结合附图对本实用新型的具体实施方作作进一步说明。The specific implementation of the utility model will be further described below in conjunction with the accompanying drawings.
参见图1、图2、图3和图4,一种低压智能无功补偿装置,包括单片机、电流电压互感器、电流电压检测电路、复合开关J1、复合开关J2、复合开关的检测驱动电路、断路器、温度传感器、人机接口、存储器和通讯接口;本低压智能无功补偿装置在工作时,首先将断路器连接在系统三相线上,断路器的三路输出端的其中两路分别连接复合开关后与电容器组连接,第三路直接与电容器组连接,两个复合开关J1和J2通过检测驱动电路与单片机连接,单片机采用型号为NEC1213的单片机;其次将电流电压互感器也安装在系统三相线上,电流电压互感器的输出端连接电流电压检测电路,电流电压检测电路的输出端连接单片机,用以将检测到的系统三相线的电流信号和电压信号输送给控制器;人机接口、存储器和通讯接口分别与单片机连接。Referring to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a low-voltage intelligent reactive power compensation device includes a single-chip microcomputer, a current and voltage transformer, a current and voltage detection circuit, a composite switch J1, a composite switch J2, a detection drive circuit for the composite switch, Circuit breaker, temperature sensor, human-machine interface, memory and communication interface; when the low-voltage intelligent reactive power compensation device is working, first connect the circuit breaker to the three-phase line of the system, and two of the three output terminals of the circuit breaker are respectively connected to The composite switch is connected to the capacitor bank, and the third circuit is directly connected to the capacitor bank. The two composite switches J1 and J2 are connected to the single-chip microcomputer through the detection drive circuit. The single-chip microcomputer adopts the single-chip microcomputer model NEC1213; On the three-phase line, the output end of the current and voltage transformer is connected to the current and voltage detection circuit, and the output end of the current and voltage detection circuit is connected to the single-chip microcomputer to transmit the detected current signal and voltage signal of the three-phase line of the system to the controller; The machine interface, memory and communication interface are respectively connected with the single chip microcomputer.
其中,电流电压互感器和电流电压检测电路为现有技术,电流电压检测电路包括模拟开关、绝对值放大电路和整形电路,电流电压互感器安装在系统三相线上,电流电压互感器将系统三相线的电流和电压转换成同比例的正弦波信号,此正弦波信号经过模拟开关后分有两路,一路接到绝对值放大电路,绝对值放大电路将信号放大后送到单片机的A/D端,用以计算电流和电压的大小,另一路经过正弦波-方波整形电路,接到单片机的中断和计时器端口,用以计算电流和电压之间的相位差,进而计算出功率因数。人机接口、存储器和通讯接口也都为现有技术,本实施例从现有技术中分别选择一款带有键盘的数字显示器、EEPROM存储器和RS485通讯接口,数字显示器通过其驱动芯片与单片机连接,用来显示单片机输出的系统参数,数字显示器上的键盘能够输入系统参数给单片机,输入的系统参数同时存储在EEPROM存储器中,当系统功率较大时,一台低压智能无功补偿装置达不到补偿的效果,参见图5,此时就可以将多台低压智能无功补偿装置通过RS485通讯接口连接起来,实现多台联合工作,而此时只需一台装置区测量功率因数和发出控制信号;作为现有技术的温度传感器置于电容器组内,温度传感器的输出直接连接单片机的A/D端口,当温度过高时,直接切断电容器组,从而保护和延长电容器组使用寿命;两个复合开关J1和J2及其驱动电路也是现有技术,其由带触点的磁保继电器和大功率的晶闸管及其检测驱动电路组成,复合开关的检测驱动电路检测电网电压与电容器组的差值电压,当两者相等时投入可控硅,以减少了可控硅的冲击,正常工作时使用磁保持继电器工作,退出时先投入可控硅,再切断磁保持继电器,从而达到无涌流,无电弧投切功能。Among them, the current and voltage transformer and the current and voltage detection circuit are existing technologies. The current and voltage detection circuit includes an analog switch, an absolute value amplification circuit and a shaping circuit. The current and voltage transformer is installed on the three-phase line of the system. The current and voltage of the three-phase line are converted into a sine wave signal of the same proportion. The sine wave signal is divided into two channels after passing through the analog switch, and one is connected to the absolute value amplifier circuit. The absolute value amplifier circuit amplifies the signal and sends it to A The /D terminal is used to calculate the magnitude of the current and voltage, and the other one passes through the sine wave-square wave shaping circuit, and is connected to the interrupt and timer port of the microcontroller to calculate the phase difference between the current and voltage, and then calculate the power factor. Man-machine interface, memory and communication interface also all are prior art, present embodiment selects respectively a digital display with keyboard, EEPROM memory and RS485 communication interface from prior art, and digital display is connected with single-chip microcomputer by its driver chip , used to display the system parameters output by the single-chip microcomputer. The keyboard on the digital display can input system parameters to the single-chip microcomputer. The input system parameters are stored in the EEPROM memory at the same time. When the system power is large, a low-voltage intelligent reactive power compensation device cannot reach To achieve the compensation effect, see Figure 5. At this time, multiple low-voltage intelligent reactive power compensation devices can be connected through the RS485 communication interface to realize the joint work of multiple devices. At this time, only one device is required to measure the power factor and send out control signal; placed in the capacitor bank as the temperature sensor of the prior art, the output of the temperature sensor is directly connected to the A/D port of the single-chip microcomputer, when the temperature is too high, directly cut off the capacitor bank, thereby protecting and prolonging the service life of the capacitor bank; two Composite switches J1 and J2 and their drive circuits are also prior art. They are composed of magnetic protection relays with contacts, high-power thyristors and their detection drive circuits. The detection drive circuit of the composite switch detects the difference between the grid voltage and the capacitor bank. When the two voltages are equal, the thyristor is put into the thyristor to reduce the impact of the thyristor. During normal operation, the magnetic latching relay is used to work. Arc switching function.
当线路上传输的功率不等于自然功率时,则沿线各点电压将偏离额定值,有时甚至偏离较大,此时采用并联电抗器对感性无功进行补偿,即在系统三相线上并联电抗器,电抗器通过复合开关并联在系统三相线上,单片机输出控制信号给复合开关,从而控制电抗器的投切,上述电抗器可以采用磁控电抗器;这样可以降低线路电压的升高,使轻负荷时线路中的无功功率尽可能就地平衡,防止无功功率不合理流动同时也减轻了线路上的功率损失。When the power transmitted on the line is not equal to the natural power, the voltage at each point along the line will deviate from the rated value, sometimes even a large deviation. At this time, a shunt reactor is used to compensate the inductive reactive power, that is, a parallel reactance The reactor is connected in parallel to the three-phase line of the system through a compound switch, and the single-chip microcomputer outputs a control signal to the compound switch to control the switching of the reactor. The above-mentioned reactor can be a magnetically controlled reactor; this can reduce the rise of the line voltage, Make the reactive power in the line balance as much as possible on the spot when the load is light, prevent the unreasonable flow of reactive power and reduce the power loss on the line at the same time.
本实施例利用瞬时无功功率理论和傅立叶算法,能在较高谐波的情况下,精确计算电网系统参数并通过单片机控制复合开关完成电容器组的投切从而实现无功补偿。根据负载实际情况,系统参数如:CT比、投切延时时间、电压上下限值、电容保护温度、目标功率因数均可通过键盘设置,所有参数都保存在外部EEROM中,即使掉电也不会丢失,上电自动运行。另外针对系统5V基准电压存在偏差,通过键盘可微调,从而实现更精准的测量。This embodiment uses the instantaneous reactive power theory and Fourier algorithm to accurately calculate the parameters of the grid system in the case of relatively high harmonics and complete switching of the capacitor bank through the single-chip microcomputer to control the compound switch to realize reactive power compensation. According to the actual load conditions, system parameters such as: CT ratio, switching delay time, voltage upper and lower limits, capacitor protection temperature, and target power factor can be set through the keyboard, and all parameters are stored in the external EEROM, even if the power is off. It will be lost, and it will run automatically when it is powered on. In addition, there is a deviation in the 5V reference voltage of the system, which can be fine-tuned through the keyboard to achieve more accurate measurement.
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Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
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CN101976822A (en) * | 2010-10-19 | 2011-02-16 | 栾银山 | Novel power capacitor |
CN102148505A (en) * | 2011-04-25 | 2011-08-10 | 北京都市鼎点科技有限公司 | Reactive compensation controller |
CN102967826A (en) * | 2012-11-05 | 2013-03-13 | 中国电力科学研究院 | Test method for electric endurance of switching capacitor set beaker of extra-high voltage project |
CN103326381A (en) * | 2013-07-19 | 2013-09-25 | 江苏南自通华电力自动化有限公司 | Low-power-consumption rapid capacitor switching switch with intelligent control |
CN108879710A (en) * | 2018-06-08 | 2018-11-23 | 贵州电网有限责任公司凯里供电局 | A kind of power distribution network efficiency optimization device and method using reactive compensation |
CN111181170A (en) * | 2020-02-27 | 2020-05-19 | 张京伦 | Controllable reactor device with capacity compensation function |
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2009
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Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
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CN101976822A (en) * | 2010-10-19 | 2011-02-16 | 栾银山 | Novel power capacitor |
CN102148505A (en) * | 2011-04-25 | 2011-08-10 | 北京都市鼎点科技有限公司 | Reactive compensation controller |
CN102967826A (en) * | 2012-11-05 | 2013-03-13 | 中国电力科学研究院 | Test method for electric endurance of switching capacitor set beaker of extra-high voltage project |
CN102967826B (en) * | 2012-11-05 | 2015-05-13 | 中国电力科学研究院 | Test method for electric endurance of switching capacitor set beaker of extra-high voltage project |
CN103326381A (en) * | 2013-07-19 | 2013-09-25 | 江苏南自通华电力自动化有限公司 | Low-power-consumption rapid capacitor switching switch with intelligent control |
CN108879710A (en) * | 2018-06-08 | 2018-11-23 | 贵州电网有限责任公司凯里供电局 | A kind of power distribution network efficiency optimization device and method using reactive compensation |
CN108879710B (en) * | 2018-06-08 | 2022-03-04 | 贵州电网有限责任公司 | Power distribution network energy efficiency optimization device and method adopting reactive compensation |
CN111181170A (en) * | 2020-02-27 | 2020-05-19 | 张京伦 | Controllable reactor device with capacity compensation function |
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