Overview

SVG series high voltage dynamic reactive power compensation device is a reactive power compensation system with IGBT as the core, which can quickly and continuously provide capacitive or inductive reactive power, realize the control of constant reactive power, constant voltage and constant power factor at the test point, and ensure the stable and efficient operation of the power system. In the distribution network, the installation of small and medium capacity SVG products near some special loads (such as electric arc furnaces, intermediate frequency furnaces, refining furnaces) can significantly improve the power quality at the connection point between the load and the public grid, such as providing power factor, balancing three-phase voltage, suppressing voltage flicker and voltage fluctuation, and controlling harmonic pollution.

Application field

Industries: Automobile manufacturing, shipbuilding, coal, petrochemical, metallurgy (steel rolling, smelting, crane), port and wharf, machinery manufacturing (welding), public facilities (lifting class), post and telecommunications, military, etc.

Working conditions: various reactive power demand occasions, especially for irregular rapid change, impact, three-phase unbalanced load. Such as welding machine, line crane, elevator, lifting platform, cable car, medium frequency furnace, electric arc furnace, cold (hot) metal calender and other loads.

Working principle

The main circuit adopts chain topology structure, modular structure design, star and triangle connection mode to achieve the maximum cost performance under different capacities, which not only ensures the effectiveness of user investment, but also ensures the stable and efficient operation of the power system. Products are mainly divided into three parts: control cabinet, power cabinet, reactor cabinet. Among them, the power cabinet achieves great unity, which facilitates the expansion and stability of the product capacity. The device of each voltage level is composed of a control cabinet, a power cabinet and a reactor cabinet (air-core reactance). With the latest design, the cooling fan can be installed directly on the top of the cabinet, reducing the installation difficulty and making installation and maintenance more convenient.

Technical characteristics

One: Modular circuit structure

1: The core of SVG is a chain inverter based on IGBT devices. Each phase of the chain inverter consists of multiple power module outputs in series, and the power module adopts N+1 or N+2 redundancy operation structure.

2: The module control adopts large-scale FPGA chip carrier phase shift multilevel space vector PWM control strategy, the circuit is simple and the anti-interference ability is strong.

3: The use of self-excited starting technology, so that the device input when the impulse current is small.

4: The module panel has a total of 4 electrical terminals and 2 optical fiber terminals, simple wiring, and a number of status and fault indicators for easy maintenance and overhaul.

Two: Control

1: MLCCON, a fully digital controller based on three DSP and multiple FPGA, has high integration and high durability.

2: The control mode can be set on site: system compensation or load compensation and load compensation harmonic number;

3: The use of fast instantaneous reactive current control strategy can achieve continuous and stable operation when the system short-circuit fault.

4: Adopt imported PLC to realize comprehensive switching control of multiple sets of fixed capacitors

5: The controller is completely enclosed and dust-proof, without cooling fan.

Three: monitoring and man-machine interface

1: The local monitoring function is jointly completed by DSP and imported PLC, using the touch screen Chinese/English display interface, which is more reliable than the embedded industrial computer interface hardware, and is more suitable for industrial field electromagnetic environment.

2: The display panel has functions such as DC voltage of the power module, fault/bypass status of the power module, output current, load current, fault display and fault recall, and can display the output current waveform.

3: With GPRS remote interface, through the networking device, the system operation data, state amount and alarm information, the use of GPRS network to send to the company's background server, to achieve real-time monitoring of the scene, has determined its security and operating conditions, reply to improve the reliability and maintainability of system operation.

Four: parameter setting function

1: With a variety of functional parameter Settings, to facilitate the on-site configuration of different load object operating parameters.

2: All function parameters are prompted in Chinese, and all function parameters have the power outage hold function (double), which can be backed up or restored as a whole.

Five: no power outage control power

1: The control power supply runs in parallel with multiple modules and is backed up by a DC UPS. When the AC control power supply fails, the DC UPS provides the control power and the device is not affected.

Six: Electromagnetic compatibility

1: The power module and the main control system are connected by optical fiber, which has a high communication rate and anti-interference ability, and good security.

Performance parameter