CN204992591U - A low pressure blend switch for reactive power compensator - Google Patents

Abstract

The utility model provides a low pressure blend switch for reactive power compensator, include: CPU, signal acquisition and take care of circuit module, circuit module, silicon controlled rectifier group, magnetic latching relay are gathered to drive circuit module, electric current, CPU connects signal acquisition and takes care of circuit module through inputoutput port, and CPU sampling junction current gathers circuit module, and CPU is through drive circuit module control connection silicon controlled rectifier group and magnetic latching relay. The utility model provides a blend switch has voltage abnormity protection, open -phase protection, power failure protection, feedback signal protection, the protection of high EMC and from multiple protect function such as diagnosis failure protections. Have still that little, the no harmonic of energy consumption pollutes, the interference killing feature is strong, advantage such as the sintering that contacts not, be not only energy -concerving and environment -protective but also safe and reliable's a low pressure blend switch that is applicable to low pressure reactive compensation.

Description

A low-voltage composite switch for reactive power compensation device

technical field

The utility model relates to a low-voltage composite switch used for a reactive power compensation device, in particular to an intelligent composite switch device for controlling harmonics of a low-voltage power grid and switching power capacitors in a reactive power compensation device.

Background technique

In the energy-saving renovation project of the power grid, it is usually necessary to add a reactive power compensation device with parallel capacitors, which has a significant effect on improving power quality and saving electricity consumption.

In reactive power compensation devices, reliable switching of capacitors is the fundamental guarantee for improving system stability. However, the existing composite switches have a lot of room for improvement in terms of safety and reliability, which correspondingly increases the cost and difficulty of later maintenance. In the current reactive power compensation device, the consideration of the signal exchange between the reactive power compensation controller and the capacitor is not comprehensive and detailed enough. In the current device, the composite switch only feeds back the switching signal to the controller, and does not make a judgment on whether the capacitor is switched accurately and successfully. This may feed back a wrong command to the controller, which threatens the stability and stability of the entire system. reliability.

In addition, the existing composite switch is not very perfect in the design of the protection circuit. For example, the self-diagnosis fault protection, power failure protection and feedback signal protection of components such as thyristors have not been fully considered, which will have a great impact on the safety and reliability of the system.

Utility model content

The purpose of the utility model is to provide a low-voltage compound switch used in reactive power compensation devices to solve the problem that the function of the current compound switch is not perfect and threatens the stability and reliability of the system.

In order to achieve the above purpose, the solution of the utility model includes: a low-voltage composite switch for reactive power compensation device, including: CPU, signal acquisition and conditioning circuit module for connecting reactive power compensation device, drive circuit module, current acquisition Circuit module, thyristor group, magnetic latching relay; CPU is connected to signal acquisition and conditioning circuit module through input and output ports, CPU sampling is connected to current acquisition circuit module, CPU is connected to thyristor group and magnetic latching relay through drive circuit module control.

The low-voltage composite switch also includes a zero-crossing detection circuit module for collecting voltage zero-crossing signals and current zero-crossing signals, and the CPU sampling is connected to the zero-crossing detection circuit module.

The low-voltage composite switch also includes a protection circuit module and an LED lamp, and the CPU controls and connects the protection circuit module and the LED lamp.

The LED lights include 1 LED power indicator and 3 LED control signal indicators for judging the working status of each phase.

Compared with the prior art, the utility model has the following beneficial effects:

The current acquisition circuit transmits the real-time collected capacitor bank current to the signal acquisition and conditioning circuit via the CPU, and feeds back the result to the reactive power compensation controller, which further determines whether the capacitor bank is successfully switched. Therefore, the reactive power compensation controller can directly monitor the current on the capacitor bank in real time, and judge whether the capacitor is switched accurately and successfully according to the current, ensuring the reliability and stability of the system. In addition, the CPU controls the operation of the thyristor group and the magnetic latching relay through the driving circuit, and then controls the on-off of the capacitor group.

Description of drawings

Fig. 1 is the structural representation of the specific embodiment of the utility model;

Figure 2 is a connection diagram of the low-voltage composite switch and the low-voltage reactive power compensation controller.

detailed description

Below in conjunction with accompanying drawing, the utility model is described in further detail.

The utility model provides a low-voltage composite switch for a reactive power compensation device, comprising: a CPU, a signal acquisition and conditioning circuit module, a drive circuit module, a current acquisition circuit module, a thyristor group, and a magnetic holding relay; The port is connected to the signal acquisition and conditioning circuit module, the CPU sampling is connected to the current acquisition circuit module, and the CPU is connected to the thyristor group and the magnetic latching relay through the control of the drive circuit module.

Based on the above technical solutions and in conjunction with the accompanying drawings, the following specific implementation is given.

As shown in Figure 1, in the low-voltage composite switch, the CPU is connected to the signal acquisition and conditioning circuit through the input and output ports, the CPU sampling is connected to the zero-crossing detection circuit and the current acquisition circuit, the CPU control is connected to the protection circuit and the LED lamp; the reactive power compensation controller is connected through The signal acquisition and conditioning circuit realizes the data exchange with the CPU; the CPU controls the connection of the thyristor group and the magnetic latching relay through the drive circuit to control the operation of the thyristor group and the magnetic latching relay, and then controls the on-off of the capacitor group. The zero-crossing detection circuit transmits the collected voltage zero-crossing signal and current zero-crossing signal to the CPU, and then controls the switching state of the low-voltage composite switch.

After the switching switch is activated, the current acquisition circuit transmits the real-time collected current of the capacitor bank to the signal acquisition and conditioning circuit via the CPU, and feeds back the result to the reactive power compensation control device, and the reactive power compensation control device further determines whether the capacitor bank is successful. cut. If the reactive power compensation control device issues a command to put in the capacitor bank, but the composite switch does not send a feedback signal back to the reactive power compensation control device, it is considered that the action has failed, and the reactive power compensation control device will send out an alarm signal and make corresponding processing. Through the intelligent judgment of the CPU, the best switching point is automatically found to ensure zero-crossing switching, small inrush current, no sintering of contacts, low energy consumption, long life, and no need for additional heat sinks.

The protection circuit of the utility model has multiple protection functions such as abnormal voltage protection, phase loss protection, self-diagnosis fault protection, power failure protection, feedback signal protection and high EMC protection.

The LED lamp in the utility model includes 1 LED power supply indicator light and 3 LED control signal indicator lights, and the working state of each phase can be visually judged according to the difference of the flickering frequency.

In the utility model, each device, circuit and module all have hardware equipment, as shown in Figure 2 is the connection diagram of each hardware equipment. The low-voltage composite switch of the utility model can be used in various occasions such as co-complementation, sub-complementation and interphase compensation. Taking sub-compensation as an example, the application of low-voltage composite switch in practical situations is briefly introduced.

The low-voltage composite switch is installed on a 380V three-phase four-wire power distribution network, and is used for on-off control of low-voltage reactive power compensation capacitors, which can compensate each phase individually. Users can install it in the low-voltage reactive power compensation control cabinet or other appropriate locations. The synchronous change of the three-phase voltage is not more than ±20%, and the interval between two consecutive connections is ≥60 seconds (waiting for 1 minute of capacitor discharge time).

As shown in Figure 2, A, B, C, and N in this device are connected to the three-phase four-wire distribution network; the three output terminals A, B, and C are connected to the capacitor; the upper 8 terminals are respectively connected to "N" and the control "12V power supply, OUT1, OUT2, OUT3, feedback A, feedback B, feedback C" terminals of the device. The reactive power compensation control device provides 12V power for the composite switch; OUT1, OUT2 and OUT3 are the signal output terminals of the reactive power compensation control device, which provide switching signals for the low-voltage composite switch; feedback A, feedback B, and feedback C are reactive power compensation The feedback terminal of the control device feeds back the real-time switching signal of the capacitor bank to the reactive power compensation control device through the low-voltage composite switch, and the reactive power compensation control device calculates and determines whether the switching of the capacitor bank is successful.

The 4 LED indicators on the outside of the device shell are "operation and input (A, B, C)", and the staff can intuitively see the operation status of the power supply and the three-phase capacitor, which provides great convenience for maintenance.

Specific implementations have been given above, but the utility model is not limited to the described implementations. The basic idea of the present utility model lies in the above-mentioned basic scheme. For those of ordinary skill in the art, according to the teaching of the present utility model, it does not need to spend creative labor to design various deformation models, formulas and parameters. Changes, modifications, replacements and modifications to the embodiments without departing from the principle and spirit of the present utility model still fall within the protection scope of the present utility model.

Claims (4)

1. A low-voltage composite switch for reactive power compensation device, characterized in that, said low-voltage composite switch comprises: CPU, signal acquisition and conditioning circuit module, drive circuit module, and current acquisition circuit for connecting reactive power compensation device module, thyristor group, and magnetic latching relay; the CPU is connected to the signal acquisition and conditioning circuit module through the input and output ports, the CPU sampling is connected to the current acquisition circuit module, and the CPU is connected to the thyristor group and the magnetic latching relay through the drive circuit module. 2. The low-voltage composite switch for reactive power compensation device according to claim 1, characterized in that, the low-voltage composite switch also includes a zero-crossing detection circuit module for collecting voltage zero-crossing signal and current zero-crossing signal, The CPU sampling is connected to a zero-crossing detection circuit module. 3. The low-voltage composite switch for reactive power compensation device according to claim 2, characterized in that, the low-voltage composite switch also includes a protection circuit module and an LED lamp, and the CPU controls and connects the protection circuit module and the LED lamp. 4. The low-voltage composite switch for reactive power compensation device according to claim 3, characterized in that, said LED light includes 1 LED power indicator light and 3 LED control signal indications for judging the working state of each phase lamp.