6-10kV water cooling dynamic reactive power compensation
- VOGA
- China
- According to customers requirement
- 10--50 pcs/day
FGSVG series high-pressure dynamic reactive power compensation device, with the chip DSP + FPGA as the core, using instantaneous reactive power theory control technology, FFT fast harmonic calculation technology, the high power IGBT drive technology, with high reliability, easy operation, high performance design goals, able to quickly continuously provide capacitive and inductive reactive power, constant testing point assessment of reactive power, constant voltage and constant power factor assessment point, as well as the comprehensive compensation and so on many kinds of control mode.FGSVG series of high voltage dynamic reactive power compensation devices can not only automatically compensate reactive power, but also dynamically compensate harmonics at the same time to ensure the stable operation of the power system.
In distribution power grid, the access of new energy, large capacity of power electronic devices such as the wide application of nonlinear load and impact load, has brought the serious power quality problems, use FGSVG high-pressure dynamic reactive power compensation device, can significantly improve the load and the public power grid connection point of power quality, such as improving power factor, to overcome the three-phase imbalance, eliminate voltage flicker, voltage fluctuation, to suppress the harmonic pollution and so on.
FGSVG high voltage dynamic reactive power compensation device is composed of control cabinet, power cabinet and reactor.The control cabinet is mainly a control box and a secondary control logic circuit, in which the control box is connected to the power unit through optical fiber.There are three-phase power units in the power cabinet. According to the different voltage levels of the power grid, each phase is composed of several power units in series, and finally it is connected to the power grid through the reactor.
The power unit adopts the cascade H-bridge circuit structure. The power unit is in series, the output is superimposed into high voltage, and it is connected to the power grid through the reactor.Power unit modular design, each unit can be interchangeable.
FGSVG control system collects voltage and current signals of the power network, uses instantaneous reactive power control theory, quickly calculates the current instructions of each power unit, and sends them to each power unit through optical fiber.Each phase of the power cabinet is composed of several power units in series. The carrier phase-shifting technology is adopted. The output voltage of each unit is superposed to form a multi-level high-voltage output.
There are three phases of voltage and current in AC circuits. When the load is resistive, the phase of voltage and current are the same.When the load shows inductance, the voltage phase leads the current phase.When the load exhibits capacitive characteristics, the voltage phase lags the current phase.FGSVG basic principle of high-pressure dynamic reactive power compensation device is controlled by H bridge circuit reactor in parallel to the grid, appropriate adjustment bridge circuit output voltage amplitude and phase, or directly control the output current, make the circuit absorption or meet the demand of power grid reactive current, to achieve the purpose of the dynamic reactive power compensation, shown in the following table.
1. Low voltage pass through technology
FGSVG high voltage dynamic reactive power compensation device through continuous technological innovation, the development and design of full performance low voltage through technology.FGSVG can provide rated capacitive current regardless of three phase short circuit fault, phase short circuit fault, or low penetration to 90% or 20%.For unbalanced low penetration, Xinsceng puts forward the theory of double phase-locked loop and double PQ control.
In 2017, the high voltage dynamic reactive power compensation device of our company passed the comprehensive test of the electrical equipment quality inspection and test center of the electric power industry.The voltage of phase A at the parallel dot remains unchanged, while the voltage of B and C drops to 20% instantly, maintains 2s, and then rises to the rated voltage. The test data is repeated three times within 1min. The test results meet the requirements as shown in the figure below.
2.Harmonic compensation technique
In medium-frequency furnace, electrolytic aluminum and other industrial and mining enterprises, due to the access of high power and nonlinear load, the low-frequency sub-current harmonic is injected into the power grid, which seriously affects the stable operation of other equipment.Our company SVG using discrete Fourier transform fast algorithm, instantaneous reactive power theory algorithm, developed a high voltage dynamic reactive power compensation device with harmonic compensation function.Because SVG carrier frequency is low (which can improve operation efficiency), the harmonic frequency of 25 times and below is governed. The lower the harmonic frequency, the higher the compensation rate.
3.Negative sequence compensation technology
There are a lot of unbalanced loads and some single-phase large capacity loads in power systems, such as electrified railways.The negative sequence and reactive current generated by these loads cause a large amount of power loss, which threatens the safety and economic operation of the power system.
The angular chain-type SVG produced by our company is an ideal compensation management method with fast response speed and can be used for reactive power and negative sequence comprehensive management.By geometric analysis of the phasor diagram of the compensation circuit, the phasor current required by the negative sequence compensation is obtained. Then, according to the instantaneous reactive power theory, the DQ /△ transformation matrix is derived, and the phase current instruction signal required by the angular chain SVG negative sequence compensation can be obtained.
4.Multi-machine parallel coordinated control technology
With the increase of power system capacity, the power system of reactive power compensation device capacity requirements also increased, because now the IGBT technology and the restriction of user division period was put into operation, many in the attendant SVG equipment run in parallel with a bus, which requires the SVG equipment can run in parallel, need parallel running each SVG can automatic power balance.
Our company has invented a simple and efficient SVG parallel operation ring fiber control system.The SVG controller running in parallel is connected into a ring by optical fiber, and the number of parallel units is not limited by the number of optical fiber interfaces of the controller.Different power levels of SVG can be used in the ring, and the reactive power output can be automatically balanced, and the reasonable use of each SVG output.Any SVG in the ring can be set up as the host, and the failure of the slave does not affect the operation of other SVG devices.
5. PT and CT wiring automatic analysis technology
In the field, SVG collects system voltage and current signals through PT and CT on site. PT wiring directly affects SVG phase-lock and grid-connection, while CT wiring directly affects SVG's calculation of reactive power and power factor at the test point.
Our SVG has the function of PT and CT wiring automatic analysis, which makes the grid-connection debugging very simple and efficient.
6.Control system self-check technology
FGSVG series high voltage dynamic reactive power compensation device, the control system adopts multi-chip DSP+FPGA technology, the control system is complex.In order to run the whole machine reliably, DSP is used to self-check the circuit board in the control box. If there is a problem with the circuit board in the control box, the problem point can be quickly located to improve the working efficiency and the intelligent level of the product.
7.Serial optical fiber communication technology
In order to isolate the strong and weak current, the SVG controller and each power unit are connected by optical fiber.The typical fiber-optic connection between the SVG controller and the power unit is that each power unit is connected to the SVG controller via two fibers.
Our company invented a serial optical fiber communication technology, and has applied for a patent.The SVG controller and the power unit are connected to a number of serial optical fiber communication loops through the optical fiber, which significantly reduces the number of optical fiber interfaces and the number of optical fibers in the SVG controller, improving production efficiency and reducing failure rate.
8.Fast tracking response
FGSVG series high voltage dynamic reactive power compensation device, through the Nanjing Institute of Electrical Technology, Wugang Institute and other third-party testing units test, the response time is less than 5ms.Tracking response time (sudden drop) Measurement waveform (up: in system: under load: test)
● Rated working voltage: 35KV;
● Rated capacity: ±0.5 ~ ± 25mVar;
● Output reactive power range: continuous change from perceptual rated reactive power to capacitive rated reactive power range;
● Response time: ≤5ms;
● Overload capacity: 1.2 times overload 1min;
Total harmonic distortion rate of output voltage (before grid-connection) : ≤5%;
The total harmonic distortion rate of output current THD: ≤3%;
● System voltage unbalance protection, setting range: 4% ~ 10%;
● Efficiency: Rated operating conditions ≥99.2%;
● Operating temperature: -20℃ ~ +40℃;
● Storage temperature: -40℃ ~ +65℃;
● man-machine interface: Chinese and English can be set color touch screen display;
● Relative humidity: monthly average is not more than 90% (25℃), no condensation;
● Cooling mode: forced air cooling, water cooling, air conditioning (optional);
● Installation: indoor, container (optional);
● Altitude: < 2000m (higher than 2000m need to be customized);
● Earthquake intensity: ≤8 degrees.
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