JKW5B Series Reactive Power Automatic Compensation Controller Three-Phase AC Compensation Controller 380V

Main technical parameters

Basic parameters

Control parameters

Measurement Accuracy

Adjustable range and factory setting values of control parameters

JKW5B Series Low Voltage Reactive Power Compensation Controller Overview

The control apparatus for fully digital operation is one that is fitted with a large LED display, modular assembly, streamlined shell design, and operational messages in Chinese for parameter setting; harmonic protection; automatic selection of either two settings of equal capacitance or fuzzy; sampling of the physical quantity called reactive power; both dynamic and static compensating; real-time display of parameters such as power factor of grid voltage, current, active power, reactive power, and distortion factor of voltage/current. . With RS-485 standard field bus interface. Customization options are available for non-standard voltage 220V, 660V, 750V, and 800V products.

Key Functions of JKW5B Series Low Voltage Reactive Power Compensation Controller

Automatic Power Factor Correction (APFC):

• Real-time monitoring of Grid Power and Supplied Power parameters, including voltage, current, and phase imbalance.
• Adjusts capacitor switching to maintain power factor ≥0.95, reducing energy losses by up to 30% and minimizing penalties from utility providers38.

Dynamic Reactive Compensation:

• Utilizes Active Reactive Power algorithms to balance inductive and capacitive loads instantly (response time ≤10ms), stabilizing voltage fluctuations and mitigating harmonic distortions (THD <5%)23.
• Supports Capacitor Switching Control with anti-resonance technology, preventing overvoltage and equipment damage8.

Intelligent Monitoring & Diagnostics:

• IoT-Enabled Remote Management: Syncs with SCADA systems via Modbus RTU/TCP or Ethernet, enabling real-time data analysis, predictive maintenance alerts, and energy consumption reports28.
• Self-diagnostic functions detect capacitor failures, phase sequence errors, and grid anomalies, ensuring uninterrupted operation3.

Robust Design for Harsh Environments:

• Operates in temperatures from -25°C to +55°C and humidity up to 90%, with IP40-rated enclosure for dust and moisture resistance38.
• High immunity to electrical interference (withstands 2000V surge pulses), ideal for industrial plants and renewable energy sites3.

User-Friendly Interface:

• LCD display shows real-time metrics: Active Power, Reactive Power in Electrical systems, power factor, and harmonic spectrum analysis8.
• Configurable manual/automatic modes for flexible installation and debugging.

Controller Working Principle

The low-voltage reactive power automatic compensation controller evaluates the phase difference between the current in one line (for example, Line A) being monitored in the three-phase power supply and the voltages of the other two lines (Lines B and C). After conducting some calculations, it determines the real-time power factor of the current power grid. This power factor is then compared to the predefined switching-in and switching-out thresholds. If, during the entire duration of the switching delay, the power factor remains within the switching threshold, no action is taken. Should the power factor drop below the switching-in threshold, one group of capacitors will be activated. On the other hand, if the power factor exceeds the switching-out threshold or is found to be negative at any point, one group of already activated capacitors will be deactivated.

This process of comparison and switching is repeated after the next switching delay until the current power factor is confirmed to be within the switching threshold.
During the switching process, if the observed voltage surpasses the corresponding overvoltage protection threshold, all connected capacitors will be deactivated in groups. However, if the voltage exceeds 10% of the selected overvoltage protection threshold, a complete deactivation of all already activated capacitors will occur as a precautionary measure. Additionally, if an undervoltage lockout is detected in the switching voltage during this process, the action will be interrupted to safeguard the system from cycling switching.

Precautions for Product Wiring

Voltage Input
The controller consists of an automatic phase sequence judgment function, but ensuring that the input voltage, as much as possible corresponds with the input current, should be ensured, that is, the phase number and phase sequence have to be consistent. With this, either BC line voltage or A-phase voltage may take the signal; the wiring method should be modified accordingly.

Current Input

• Current is taken from the A-line current. The standard rated input current is 5 A. When it is greater than 5 A, an external current transformer (CT) should be used.
  Though there is an automatic phase sequence judgment capability in this controller, the inputs should be of the same nature with respect to phase and phase sequence-number.
  If other instruments are connected to the CT, the wiring should be in series.
  Disconnect the primary circuit of the CT or short circuit the secondary circuit before removing the current input wiring of the product. 

CT Connection

• To make disassembly and assembly easy, terminal blocks should be adopted instead of directly connecting the CT.

Communication Wiring

• An asynchronous half-duplex RS485 communication interface has been implemented in the network power meters for the use of data messaging on the communication line following the MODBUS-RTU protocol. A maximum of 128 network power meters can simultaneously connect on one line with every network power meter having its communication address (Addr) set. 
  For communication connection, it is advisable to use shielded twisted pair wires, having a thickness of not less than 0.5 mm. The common terminal could be otherwise left unused, or if the common terminal is connected to the ground, then a 'single-end single-point grounding' system must be followed. Connect a terminal matching resistor of 120 Ω to 1 kΩ between A and B terminals of the terminal meter. When wiring, the communication line should be kept away from strong current cables or other strong electromagnetic field environments. 
  To protect communication interfaces and the safety of the controller itself, switch quantity input interface and temperature interface must be insulated from other active devices in outside since here RS485 is not isolated with such interfaces.

Quantity output by main switch
Active quantity output is the switching control of compensation capacitors for synchronizing different customers' commands as 6, 8, 10, or 12 channels. Capacitor switching includes first-in-first-out switching, sequential switching, manual switching, and communication switching.

• This mode, called sequential switching, is found appropriate when the different groups of compensation capacitors have different sizes. Each group of compensation capacitors must be wired in decreasing sequence of size. The largest in capacity should go to K1, and the last terminal would connect to the smallest.
• First-in-first-out switching suits groups of identical size compensation capacitors. Under such condition, the first-in-first-out method provides for equal wear and tear of the operating time for each group of capacitors.
• Mainly for debugging stage purposes, manual switching is used to assess wiring and effects of compensation. In the measurement display mode, it allows input and output of capacitance by left and right keys.
•  Communication switching remotely controls the capacitors through instructions from the controller. The controller abandons its control function at that time but keeps the protection part. Other devices perform capacitor switching writing relevant content to the controller through communication.

Product Size