CN201260079Y - Synthetic apparatus for power distribution monitoring and intelligent passive optimization - Google Patents

Abstract

The integrated device for power distribution monitoring and intelligent reactive power optimization is characterized in that the composition of the device includes a circuit breaker QF, which is connected in series between the device and the three-phase lines A, B, and C of the system, and the circuit breaker QF is closed to make the controller TTU work ; A controller TTU, by detecting the amplitude and phase difference of the three-phase voltage and three-phase current of the system, calculates the reactive power of the system, and compares it with the set input threshold and cut-off threshold, and controls the compensation capacitor through the compound switch FK Input or exit of C; a compensation capacitor bank C, under the control of the controller TTU, enters or exits the system in groups and phases. The utility model adopts an on-site balanced working mode, which can effectively reduce power loss, increase the qualified rate of voltage, and improve the reliability of equipment operation.

Description

Power distribution monitoring and intelligent reactive power optimization integrated device

technical field

The utility model relates to a power distribution monitoring and reactive power optimization comprehensive device used in equipment such as box-type transformers, outdoor distribution transformers, and low-voltage complete sets.

Background technique

Due to the continuous increase of the grid capacity, the reactive power requirements of the grid are also increasing day by day. Like active power, reactive power is an integral part of ensuring power quality. In the power system, the balance of reactive power should be maintained, otherwise it may cause voltage drop, equipment damage, power factor drop, and in severe cases, the voltage of the system will collapse, causing large-scale power outages.

Domestic manufacturers and users mostly use static reactive power compensation in addition to constant voltage transformers when solving the problem of reactive power optimization and network loss reduction in the power grid. This compensation method has the following problems:

1. After the capacitor is put into operation, overcompensation often occurs, reactive power is sent back to the power grid, and the voltage of the power grid rises, which endangers the safe operation of the power grid and equipment, increases network loss, and reduces the voltage qualification rate.

2. After the capacitor is put into operation, under-compensation occurs, the reactive power of the grid cannot be fully compensated, the power factor is low, and the grid voltage is low, which endangers the safe operation of the grid and equipment, increases network loss, and reduces the voltage qualification rate.

3. A small number of products using dynamic reactive power compensation cannot fully "understand" users and the power grid, and only "make up for any shortage" and "make up for as much as there is a shortage", which is likely to cause impact on the power grid or affect the life of equipment due to frequent operation.

Utility model content

The utility model is to avoid the shortcomings of the above-mentioned prior art, and provides a comprehensive device for power distribution monitoring and intelligent reactive power optimization, so as to realize the local balance of reactive power in the power grid, reduce power loss, and improve the voltage qualification rate , The purpose of the invention to improve the reliability of equipment operation.

The utility model solves the technical problem and adopts the following technical solutions:

The integrated device for power distribution monitoring and intelligent reactive power optimization has a structural feature that the composition of the device includes:

A circuit breaker QF, connected in series between the device and the three-phase lines A, B, and C of the system, the circuit breaker QF is closed to make the controller TTU work;

A controller TTU, by detecting the amplitude and phase difference of the three-phase voltage and three-phase current of the system, calculates the reactive power of the system, and compares it with the set input threshold and cut-off threshold, and controls the compensation capacitor C through the composite switch FK input or withdrawal;

A compensation capacitor bank C, under the control of the controller TTU, enters or exits the system in groups and phases through the composite switch FK.

Structural features of the present utility model also are:

The TTU of the controller adopts DSP digital signal processing chip, and the analog quantity is input through AD conversion, and the switch quantity is directly input, and the switch quantity is output; RS485/232 communication serial port and GPRS communication module are configured to remotely transmit distribution information and capacitor input and resection information.

Compared with the prior art, the beneficial effects of the utility model are reflected in:

1. The utility model is equipped with a TTU controller. When the reactive power deficit value increases to the set value, the controller outputs a zero-crossing trigger pulse to the specified composite switch to conduct it and put the capacitor into operation until the power deficit approaches the set value. Fixed value, when the reactive power deficit value drops below the set value, the controller stops sending the trigger pulse signal and withdraws the capacitor to prevent the voltage from being too high. This in-situ balanced working method can effectively reduce power loss, increase the voltage qualification rate, and improve the reliability of equipment operation.

2. The TTU controller of this utility model adopts DSP digital signal processing technology to realize the integration of power distribution monitoring and reactive power optimization control.

3. By setting and optimizing the reactive power compensation strategy model, the utility model can automatically cycle grouping, phase-separate switching capacitors, prevent overcompensation, and adapt to different load characteristics in the power grid.

4. The utility model has various communication interfaces such as GPRS, and is easy to form a network.

5. The utility model realizes the combination of the compensation device and the metering box. The combination device is beneficial to reduce the cost, reduce the occupied space and reduce the maintenance workload.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the utility model system.

Labels in Figure 1: QF circuit breaker, BL arrester, FU fuse, FU1 fuse, FK composite switch, TTU controller, C capacitor bank, LK switching indicator light.

Fig. 2 is a schematic diagram of the composition of the utility model controller:

Detailed ways

Referring to Figure 1, the settings in this embodiment include:

A circuit breaker QF, connected in series between the device and the three-phase lines A, B, and C of the system, the circuit breaker QF is closed to make the controller TTU work;

A controller TTU, by detecting the amplitude and phase difference of the three-phase voltage and three-phase current of the system, calculates the reactive power of the system, and compares it with the set input threshold and cut-off threshold, and controls the compensation capacitor C through the composite switch FK input or withdrawal;

A compensation capacitor bank C, under the control of the controller TTU, enters or exits the system in groups and phases through the composite switch FK.

As shown in Figure 2, the controller is composed of 9 functional modules, namely analog input and A/D conversion circuit, digital input circuit, digital output circuit, working power circuit, signal processing unit circuit, communication circuit, watchdog And system reset circuit, system calendar clock circuit, analysis data storage circuit.

In this embodiment, the controller TTU adopts a DSP digital signal processing chip, and the analog quantity is input through AD conversion, and the switch quantity is directly input, and the switch quantity is output; RS485/232 communication serial port and GPRS communication module are configured to transmit distribution information remotely And capacitor input and removal information, to achieve remote monitoring.

Use the controller TTU to collect the three-phase voltage and current in the power grid, and calculate the actual reactive power and power factor of each phase. When the reactive power deficit of a certain phase increases to the set value, it meets the requirements of the capacitor input. condition, the controller outputs an input command to the specified composite switch FK, and the composite switch KF is turned on at the moment when the voltage crosses zero, so that the capacitor C of the corresponding phase is put into operation until the power deficit approaches the set value; similarly, when the reactive power When the shortfall value drops below the set value, the controller TTU cancels the input command to the designated composite switch, and the composite switch FK is disconnected at the moment when the current crosses zero, so that the capacitor C of the corresponding phase is removed until the preset requirements are met. When the capacitor C of a certain phase is put into operation, the switching indicator lamp LK of the corresponding phase is lit.

In the specific implementation, set the threshold value of input and removal of capacitor C, so that the reactive power is maintained within the required range, and the blocking value of voltage, maximum current blocking value, comprehensive harmonic blocking value, capacitor input or removal can be set delay time etc.

In addition, the intelligent composite switch FK composed of bidirectional anti-parallel thyristor and magnetic latching switch can be used to switch the power capacitor C. It also has the advantage of zero power consumption of the magnetic latching switch during the on-off period, which prevents the equipment from being burned due to arc impact during switching, and improves the reliability of the equipment operation.

The utility model is suitable for a 380V low-voltage power distribution network and can be installed and used indoors or outdoors.

Compensation method: a combination of three-phase compensation and phase-separated compensation, and a hybrid compensation method that combines common compensation and sub-compensation. The co-compensation capacity is configured in one group according to the capacity of the distribution transformer. Configure according to user requirements. Switching mode: automatic cycle switching, that is, the first switch is broken first, the last switch is switched on, and the capacitor bank works in turn.

Claims (2)

1. The comprehensive device for power distribution monitoring and intelligent reactive power optimization is characterized in that the composition of the device includes: A circuit breaker QF, connected in series between the device and the three-phase lines A, B, and C of the system, the circuit breaker QF is closed to make the controller TTU work; A controller TTU, by detecting the amplitude and phase difference of the three-phase voltage and three-phase current of the system, calculates the reactive power of the system, and compares it with the set input threshold and cut-off threshold, and controls the compensation capacitor C through the composite switch FK input or withdrawal; A compensation capacitor bank C, under the control of the controller TTU, enters or exits the system in groups and phases through the composite switch FK. 2. The comprehensive device for power distribution monitoring and intelligent reactive power optimization according to claim 1, characterized in that the controller TTU adopts a DSP digital signal processing chip, and the analog quantity is input through AD conversion and directly with the switch quantity, so as to Switch output; equipped with RS485/232 communication serial port and GPRS communication module, remote transmission of distribution transformer information and capacitor input and removal information.

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