Automatic Capacitor Controller

The JKW-F3 Automatic Capacitor Controller is a high-performance device for automatic reactive power compensation with split-phase control. At the heart of this product is a powerful microprocessor that simultaneously samples three-phase voltage and three-phase current. A standout feature is its capacity to provide up to 24 output circuits from a single controller, supporting full split-phase, full common-phase, or hybrid common+split phase compensation modes. It also presents users with 12 capacitor combination modes (capacity coding) to choose from. Control parameters can be modified via its interface and are permanently saved upon setting. This product employs a dual-parameter control strategy based on fundamental power factor and fundamental reactive power to command capacitor bank switching, delivering stable performance free from oscillations. Its operation is not affected by harmonic interference, allowing it to display accurate electrical data and execute correct switching commands. The product boasts a character-based LCD screen, offering a user-friendly interface, simple operation, and a modern, attractive appearance. It is designed for automatic control of reactive power compensation in 0.4KV electrical systems. The functional highlights of this Automatic Capacitor Controller are:

• 1. Its control logic using fundamental power factor and reactive power prevents various switching oscillations and ensures reliable operation and correct data display in harmonic-rich environments.
• 2. It provides high measurement accuracy for power factor across a broad display range.
• 3. It offers 12 different capacitor capacity coding schemes for selection.
• 4. A single product unit can manage a maximum of 24 output circuits, with flexible allocation between split-phase and common-phase loops.
• 5. The large LCD screen displays information in Chinese, making operation quick and convenient; all parameters are paired with Chinese text, and data is presented digitally.
• 6. It includes both Automatic and Manual operating modes, with memory retention for settings.
• 7. It features one configurable passive alarm output port.
• 8. All control parameters are stored in non-volatile memory, preventing loss during power failures.
• 9. Comprehensive protection includes over-voltage, under-voltage, excessive voltage harmonics, excessive current harmonics, and over-temperature conditions.
• 10. The target power factor can be adjusted over a wide range.

The technical specifications for the Automatic Capacitor Controller are detailed: Sampling Voltage: AC220V ±20% (from a three-phase four-wire system); Sampling Current: AC 0.1A to 5.0A (an under-current state occurs below 100mA); Operating Frequency Range: 45Hz to 65Hz; Under-voltage Threshold: 180V; Dynamic Output: DC12V, 10mA per branch, with a positive common terminal; Static Output: Passive relay contact rated at 250V 3A; Alarm Output: Passive relay contact rated at 250V 3A; Total Power Consumption: ≤10W; Enclosure Protection: IP30; Connection Type: Plug-in terminal blocks secured by screws; Mounting Style: Flush/panel mounting using snap-in fixings.

To ensure the product performs reliably, please follow these installation and working conditions:

• 1) Do not install above 2500 meters altitude;
• 2) Maintain an ambient temperature between -20℃ and +50℃;
• 3) Control humidity to ≤50% at 40℃ and ≤90% at 20℃;
• 4) Install in a clean area without corrosive gases, conductive dust, or flammable/explosive materials;
• 5) Select a mounting location free from severe vibration or shock.

The wiring diagram is drawn with all functions complete. If a part does not have a wiring port, then that function is not available. Note: The sampling current only supports current transformers with a secondary current of 5A. If you have special requirements, please contact our company.

Three-transformer sampling method (for situations requiring phase-by-phase compensation)

Sampling method for a single current transformer (in cases where phase-specific compensation is not required, all are common-compensation).

Dynamic output (DC 12V, common terminal positive, loop output negative, 10mA/branch)

This controller can be equipped with an additional RS485 communication interface. This interface can be used either to connect to a computer or for loop expansion purposes; however, these two functions are mutually exclusive. When used for computer connection, our company provides free background testing software. If the number of control loops required by the customer exceeds the capacity of a single controller, a loop expansion module can be purchased separately. In this case, the communication interface will be dedicated solely to loop expansion functionality.

Currently, there are three primary methods for configuring capacitor bank switching capacities on the market:

Cyclic Switching: Uses capacitor banks of equal capacity. With a low number of loops, each bank has a large capacity, resulting in low compensation precision. Increasing the number of loops to improve precision significantly raises costs.

Arbitrary Capacity Switching: Employs capacitors of varying, irregular capacities. This method requires setting the capacity for each loop individually, making configuration cumbersome, especially with a high number of loops. Furthermore, the compensation characteristic is non-linear.

Capacity-Code-Based Switching (Used by this controller): Only two parameters need to be set: "Capacity Code" and "Step Capacity". The system then automatically calculates the subsequent capacitor bank capacities. This method offers simple setup and high compensation accuracy. Naturally, the available combinations are constrained by the variety of coding schemes.

Given the high number of output loops in this controller, the third method-capacity-code-based switching-is the most rational choice. The controller currently offers 12 preset capacity codes. We will continue to strive to increase the variety of codes based on customers' practical application needs, in order to better accommodate diverse configuration requirements.