Xu Shuang
Ankerui Electric Co., Ltd. Â Â Â Jiading 201801
Abstract : This paper introduces the working principle of parallel active filter device and its application in distribution network of factories and mines. It compares the passive and active filter technology in harmonic control. It is proved that the shunt active filter device is a combination of practice. Harmonic pollution of effective equipment will have broad application prospects in the future.
Keywords : harmonics active filter device hybrid compensation
Introduction: In recent years, many factories and mines have used thyristor rectification and converter equipment, electric arc furnaces, intermediate frequency furnaces and other harmonic interference source load devices. These devices absorb a large amount of reactive power and reduce the user's power factor. Harmonic problems are getting worse. According to the standard and management regulations for power quality in the power industry, local power supply departments have issued corresponding harmonic limit criteria and measures, and assessed and treated enterprises and institutions with serious harmonic pollution. Therefore, filtering harmonics, increasing power factor, and extending equipment life are the top priorities of such enterprises for energy conservation, consumption reduction, and improvement of production efficiency and product quality.
The traditional methods of harmonic suppression and reactive power compensation are passive filter devices made up of inductors and capacitors. The device is connected in parallel with the nonlinear load to be compensated. It provides a low-resistance path for harmonics and also provides a load for the load. Required reactive power. Although the passive filter device has the advantages of simplicity and convenience, it also has many disadvantages.
Active power filter (APF) devices can not only reduce the floor space, but also effectively solve the problems of passive filter devices. There is an essential difference between active filtering and passive filtering. It is based on the principle of dynamic compensation of harmonics. It uses modern power electronics and computer technology to quickly track the harmonics generated by harmonics and their characteristics. The device sends the inverse of the corresponding frequency. The current, so as to achieve the purpose of filtering out multiple harmonics at the same time. It is generally composed of electronic power converters with high controllability and fast response of semiconductor power converters.
1 Application case of ANAPF low voltage active filter in the factory
1.1 Project Introduction
There are 5 sets of rectifier transformers in the distribution system of Qinhuangdao Electronic Co., Ltd., mainly supplying power to 10 melting intermediate frequency electric furnaces. This type of equipment adopts a 12-pulse thyristor rectification method, which generates severe non-sinusoidal distortion and a large number of higher harmonics in the production process, causing serious interference to its own distribution system and the public power grid. At the same time, because the non-linear load is inductive, the power factor of its own power distribution system deteriorates, and the 11th and 13th harmonic currents on the 10kV line side exceed the requirements of the national standards, which in turn greatly affects the power distribution system and the public power grid. quality. Without harmonic control, not only cause harm to the company's own distribution system, but also endanger public safety network.
1.2 ANAPF filter device principle
ANAPF series active power filter devices are connected to the power grid in parallel and detect harmonics and reactive components of the load in real time. PWM inverter technology is used to generate one current harmonic component and reactive component from the converter. The reverse component is injected into the power system in real time, so that harmonic control and reactive power compensation are achieved.
The principle is as follows:
1.3 program design
The 10kV high-voltage system is divided into 4 sections and 5 sections busbars. The active power filter capacity of each busbar is 450A. Three models of ANAPF100-400/B filters are used in parallel, and the harmonics are converted by a 0.4kV/10kV harmonic transformer. The wave is sent to the 10kV side and the harmonics of the load are superimposed to achieve harmonic cancellation with the power grid.
System diagram after the filter is put into operation
1.4 Harmonic current spectrum comparison chart before and after treatment:
1.5 governance effect
After using two sets of active power filter devices to control the 4k and 5th segments of the 10kV busbar, the system harmonics are well suppressed, and the 11th and 13th harmonics are completely limited within the scope of the national standard to improve power supply. The power supply reliability of the system eliminates the hidden dangers of system harmonics affecting the power grid system. It has received good results and achieved the purpose of improving the power quality of the power grid.
2 ANAPF Active Filter Introduction
2.1 Technical parameters
Wiring
Three-phase three-wire or three-phase four-wire
Access voltage
3×380V ±10%
Access frequency
50Hz ±2%
Dynamic compensation response time
Dynamic response <4ms, full response time <20ms;
On-off level
10kHz
Function settings
Only harmonics are compensated, only reactive power is compensated, both harmonics are compensated and reactive power is compensated; manual and automatic switching are performed.
Harmonic compensation times
2-21 times
Type of protection
DC over-voltage IGBT over-current device temperature protection
Overload protection
Automatic current limit in the set value, no overload occurs
cooling method
Smart air cooling
noise
< 65db (in the cabinet and operating in the rated state)
Working temperature
-10°C to +45°C
Working environment humidity
<85%RH non-condensing
Installation occasion
Indoor installation
Altitude
≤1000m (for use at higher altitudes)
Incoming and outgoing ways
Down in and out
Protection level
IP21
Intelligent communication interface
RS485/MODBUS-RTU
Remote monitoring
Optional
Overall size (mm)
(W×D×H)
30A
50A
75A
100A
600×500×1500
600×500×1500
600×500×1800
800×600×2200
Weight (kg)
Three-phase four-wire
Three-phase three-wire
30A, 50A
75A, 100A
30A, 50A
75A, 100A
280
360
240
290
Explanation:
1. The compensation current can be determined by the measured data, or the compensation current can be calculated through detailed information of the power system (single line diagram, transformer, load condition, etc.);
2. Two or three CTs must be configured for the three-wire system (for A-phase and C-phase), and three CTs for the four-wire system (for A-phase, B-phase, and C-phase).
2.2 ANAPF Active Filter Quotation and Component List
Model Number: ANAPF100-400/B
Reference price: 120,000 yuan/set
The main product details:
No.
Name
Model number
Quantity
1
APF electrical cabinet
800X600X2200
1
2
Converter
APFCOV-CVT100
1
3
Controller
APFMC-C100
1
4
Reactor
APF-RE.(S)DG-100
1
5
Active current transformer
LT208-S7
3
6
filter
DL-1TH1
2
7
breaker
CVS160FTM160D4P3D
1
8
Contactor
LC1D150M7C
1
9
MCB
NDM1-63C32
1
10
Intermediate relay
MY4NAC
2
11
R type transformer
R320-0.38/0.22
1
12
Harmonic Detector
ACR350EGH
1
13
wire
16mm2
Some
14
wire
4mm2
Some
3 parallel ANAPF application advantages
1) Filter out harmonics
ANAPF has a wide range of filtering and high filtering efficiency, and the filtering rate can reach over 92%. Passive filtering equipment uses the compensation capacity to set the LC filter branch for a fixed sub-harmonic, and the filtering effect of its sub-harmonic is poor. Harmonic components for this system are very complex, and the system power factor is already high. The fundamental wave compensation capacity is too small, and it is impossible to set a specific LC filter branch at all times to ensure that the filtering rates meet the requirements. In particular, the second harmonic content of the system is relatively large. According to the principle of the LC filter branch, the second harmonic impedance and the fundamental wave are almost the same, and the filtering rate is extremely low.
2) Preventing harmonic amplification and suppressing resonance function
ANAPF has no energy storage elements and is not affected by changes in system parameters and design parameters. It will not be resonant with the system. Passive filtering equipment that sets high-order filter branches will amplify low-order harmonics, while system 2~ The 13th harmonic content is large, and the set filter branch can easily amplify other harmonics; the inconsistent or inconsistent change of system parameters and design parameters cannot be applied, and there is a risk of resonance with the system.
3) Others
The response time of ANAPF is less than 10ms, and the delay time is less than 100us. The reactive power compensation can be programmed to compensate for capacitive and reactive power, and can also be used for compensating inductive and reactive power. It has strong load carrying capacity, automatic current limiting, no overload, and high service life. Small size, easy to install; Passive filter devices have slow dynamic response; they can only compensate capacitive reactive power; due to the characteristics of LC devices, LC parameters may change after long-time operation; bulky and complicated debugging.
4 Conclusion
1) The modular parallel active filter device designed in this paper is a new type of filter compensation device that can be used in low voltage distribution systems. The device itself can simultaneously compensate the system's higher harmonics and fundamental reactive power, has a high degree of self-adaptability, and has high filtering accuracy and good compensation effect.
2) The device's own protection features are perfect, which can inhibit the parallel or series resonance caused by the system parameter change, and can also prevent reactive over-compensation.
3) On the basis of the original capacitor reactive power compensation device of the enterprise, the filter and reactive power hybrid compensation system consisting of a capacitor and an active filter device is designed, which saves the user's investment cost and shortens the construction period. The harmonic control project of the distribution network provides an efficient compensation device with good application value and application prospects.
4) The expansion of the capacity of the active filter device module and further improvement of its voltage level can be used as future research directions.
ã€references】
GB/T 14549-1993 "Power Quality: Harmonics in the Public Power Grid" Luo Shiguo.Compensation characteristics of passive power filters and analysis of existing problems[J].Power System Technology, 2004,28(22):40-43 Anke Rui Electric Co., Ltd. Product Brochure. 2013.01.About the Author:
Xu Shuang, female, undergraduate, Ankerui Electric Co., Ltd., the main research direction for the smart grid power distribution, Email: Mobile QQ
"AAPF Active Power Filter Device Design and Application Atlas" (atlas number: ACR13CDX701) is edited by Ankerui Electric Co., Ltd. This atlas combines the characteristics of ANAPF active power filter device products, based on electrical design specifications, research Eliminating the problem of high-order harmonics in the power supply and distribution system to achieve the goal of improving the quality of power supply and ensuring the safe operation of the power system. The Atlas is applicable to the design and modification of harmonic suppression and comprehensive management of electrical equipment in industrial, civil, and public buildings in new construction, reconstruction, expansion, and technological transformation projects. If you need atlas, please provide your organization's name, department, address, zip code, contact person, contact telephone number, email address, fax 021-69155331, mail or QQ to Ankeru Xu cream engineer, Ankerui Electric will give you a free gift. .
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