Intelligent filtering reactive power compensation module

The harm of harmonics to power capacitors
Once the harmonic current is amplified by the capacitor and superimposed on the fundamental wave current of the capacitor, this will increase the effective value of the current flowing through the capacitor, and the power capacitor will increase the additional insulation loss due to the harmonic current. , The temperature rises, accelerates the capacitor insulation aging, and even causes overheating to damage the capacitor. In addition, once the harmonic voltage increase caused by the amplification of the harmonic current is superimposed on the fundamental voltage of the capacitor, the effective value of the capacitor voltage will also increase, and the voltage peak value will also increase greatly, causing the capacitor to produce partial discharge and cannot be extinguished. This is also a major cause of capacitor damage.
Due to the amplifying effect of the capacitor on the harmonic current, it not only harms the capacitor itself, but also endangers other electrical equipment in the power grid. In severe cases, it will cause damage to the electrical equipment and even destroy the normal operation of the power grid. Therefore, it is necessary to solve the capacitor's The amplification of wave current strengthens the suppression and prevention of harmonics.

Main purpose and scope of application The
ZUIC-9K series intelligent filter reactive power compensation module is composed of an intelligent measurement and control unit, an intelligent zero-crossing switching relay, an intelligent protection unit, and a low-voltage filter power capacitor to form an independent and complete intelligent compensation unit. It replaces the automatic reactive power controllers, fuses (or micro-breaks), thyristor composite switches (or contactors), thermal relays, indicator lights, low-voltage power capacitors, and dry series reactors. Power compensation device.
The product is mainly used for reactive power compensation in places with severe harmonics. It can operate reliably without resonance, has no amplification effect on harmonics, and has the function of absorbing and eliminating harmonics to a certain extent. Among them, products with 6% and 7% reactors in series are used in electrical environments where the main harmonic is 5th order, and products with 12% and 13% reactors in series are used in electrical environments where the main harmonic is 3rd order.
This product complies with: National Standard GB! Ding 15576-2008 (our company is the main drafting unit of this standard)

Features

Modular structure The
smart capacitor is a modular structure with small size, simple field wiring and convenient maintenance. Only need to increase the number of modules to realize the expansion of the reactive power compensation system.

Zero-crossing switching
Zero-crossing switching is realized by the core device intelligent zero-crossing switching relay to achieve zero-voltage switching and zero-current switching, that is, "zero-crossing switching", which reduces system power consumption. Therefore, the capacitor switching process has no inrush current impact, no removal of overvoltage, and no arcing.

Protection function
Smart capacitors have over voltage, over current, under voltage, loss of voltage protection, phase loss, short circuit protection, capacitor and reactor over temperature protection, harmonic overrun protection, capacity loss overrun alarm, switching fault alarm, circuit The functions of fault alarm and communication fault alarm can effectively ensure the safety of capacitors and prolong the life of equipment. Low-voltage power capacitor body temperature protection is one of its important protections, and the working power supply voltage is too high. Excessive harmonics and high ambient temperature will seriously affect the service life of low-voltage power capacitors. Setting the internal temperature protection of the low-voltage power capacitor can exit operation when the internal temperature exceeds the value, thereby prolonging the service life of the low-voltage power capacitor.

The
switching criteria of the control technology are power factor and reactive power. Reactive power flow prediction and delayed multi-point sampling technology are adopted. When the power factor is lower than the set value, the switching is controlled according to the load reactive power deficiency classification difference to ensure switching No oscillation. When the load is heavy, the reactive power is fully compensated.

Intelligent network function The
controller is optional, and the intelligent capacitor can work as a system to realize the low-voltage reactive power automatic compensation function. The individual intelligent reactive power compensation capacitor will automatically exit after failure and will not affect the rest of the work. Using intelligent network technology to build a 485 communication network, multiple capacitors are used in parallel to automatically generate a network, where the one with the smallest address code is the host, and the rest are the slaves. It constitutes a low-voltage reactive power automatic control system. The failure of individual auxiliary machines will automatically exit without affecting the rest of the work. The main machine will automatically exit if failures occur, and a new main machine will be generated in the remaining auxiliary machines to form a new system.

High-quality power capacitors
. The capacitor components in smart capacitors adopt a progressive thickening silver-zinc coating process. The silver-zinc coating has good conductivity and stability, and the thickness is proportional to the current density there, so the heat generation is small and uniform during operation , It greatly improves the capacity stability of low-voltage power capacitors, with very little attenuation. The overall high-vacuum immersion technology of the capacitor ensures that the capacitor has excellent stability and long service life.
Man-machine communication The
use of large LCD screen full Chinese display and keys to realize man-machine communication. Real-time display of network status and capacitor operating data on the LCD: including reactive power, system power factor, voltage, current, capacitor current, harmonic distortion rate, capacitance capacity, capacitor body temperature, CT transformation ratio, number of online units, etc.

Fault self-diagnosis technology
Real-time monitoring of the operating conditions of the internal zero switching switches, circuit breakers, capacitors and other parts of the smart capacitor, and real-time Chinese prompts on the LCD. Facilitate rapid fault location. In order to achieve maintenance-free.

The fool operation mode
can automatically identify and set the transformer ratio of the external main cabinet, and automatically identify the sampling signal polarity of the secondary transformer. There is no worries about wrong connection of the wiring, each unit can automatically generate the communication address code, without manual setting, that is, it is connected and used.

Hybrid compensation function
can realize split-phase compensation. In the case of unbalanced three-phase load, the combination of three-phase and split-phase can be used. According to the size of the reactive power shortage of each phase, the three-phases are switched on and off separately to achieve reactive power optimization.

The filtering function
effectively suppresses the high-order harmonic inrush current and forms a low-impedance path for the high-order harmonics. It can absorb and discharge harmonics, eliminate the impact of high-order harmonics on capacitors, reduce and suppress harmonic currents and flicker currents, protect circuits and capacitors from overload, prevent capacitors from overheating, aging of insulating media, and degradation of self-healing performance , The service life is reduced.

Convenient installation and maintenance The
installation design of ZUIC-9K series intelligent filter reactive power compensation module is a seat installation, modular structure, flexible combination, convenient expansion, simple installation in a low-voltage complete cabinet, and easy maintenance.

The dry type series reactor of high-quality dry type series
reactor is small in size, light in weight, high quality, low temperature rise, low power consumption, and has a very high heat resistance level, which can ensure that the reactor is safe at high temperatures The ground runs without noise.

Model and meaning

The serial number of the product design is such as:
ZUIC-9KS/0.48-40-7% means a total of 40kvar capacitor voltage 480V is connected in series with 7% reactance, and three-phase compensation is used for 380V system.
ZUIC-9KF/O.28-20-7% means that the 20kvar capacitor voltage 280V is connected in series with 7% reactance, and the phase compensation is used for the 380 system.

The reactance rate of series reactor is generally 7% or 13%.
The capacitor voltage is generally 480V or 525V for three-phase compensation, and 280V or 300V for split-phase compensation, which has high reliability.
Products with a reactance rate of 7% are mainly used in occasions with a higher harmonic content of the 5th and above; products with a reactance rate of 13% are mainly used in occasions with a higher harmonic content of the 3rd and above.

product model

Note: A total compensation product has one circuit; a separate compensation product has three circuits (one circuit for each of the ABC phases).
Human-computer interaction

Product installation wiring diagram

Shape and installation dimensions

Main technical parameters
Environmental conditions
1. Ambient temperature: -45°C-55°C;
2. Relative temperature: 40°C, 20-90%
3. Altitude: ≤200Om;

Power conditions
1. Working voltage: 380V/220V±20%;
2. Power consumption: <0.5W (when the capacitor is removed); <5W (when the capacitor is put into operation);

Electrical safety The
electrical clearance and creepage distance, insulation strength, safety protection, short-circuit strength, sampling and control circuit protection meet the requirements of the corresponding clauses in the People’s Republic of China Electric Power Industry Standard DL/T842-2003 "Technical Conditions for the Use of Low-Voltage Shunt Capacitor Installations";

Protection error
1. Voltage: ≤0.5%;
2. Current: ≤1.0%:
3. Temperature: ±1℃ (capacitor), ±30℃ (reactor);
4. Time: ±0.Ols;

Zero switching parameters
1. Zero switching offset: ≤2.5o;
2. Voltage shock resistance: ≥AC2500V (DC4000V);
3. Current shock resistance: ≥50 times the rated current;

Reliability parameters
1. Control accuracy rate: 100%;
2. Allowable switching times: 1 million times;
3. Capacitor capacity operating time attenuation rate: ≤1% year;
4. Capacitor capacity switching attenuation rate: ≤0.1% million Times;
5. Annual failure rate: ≤0.1%;

Reactive power control parameters
1. Reactive power control error:
≤75 % of the minimum capacitor capacity; 2. Reactive power capacity: single unit ≤(40)kvar three-phase; ≤30kvar (phase separation);

Measurement error
1. Voltage: ≤0.5% (within 80-120% of the rated voltage of the power supply);
2. Current: ≤1% (within the range of 5-20% of the rated current); ≤0.5% (within 20-120%) Within the rated current range);
3. Power: ≤1%;
4. Temperature: ±1℃;

Typical design electrical schematic diagram

Low-voltage complete cabinet three-phase compensation application electrical wiring diagram (with controller)

 
Low-voltage complete cabinet mixed compensation application electrical wiring diagram (without controller)

Reference table for the number of smart capacitors installed

Note: The intelligent filter reactive power compensation module product has a reactor, which generates a large amount of heat during operation, so a temperature-controlled cooling fan should be installed in the electrical cabinet.
When the number of ordinary intelligent reactive power compensation capacitors is large, in order to facilitate heat dissipation, a temperature-controlled cooling fan should be installed in the electrical cabinet.