Basler Electric SSE‑N 125‑4.5KW – Shunt Exciter Voltage Regulator

The Basler Electric SSE‑N 125‑4.5KW is a robust shunt exciter regulator designed for controlling the excitation of synchronous generators. This unit provides precise voltage regulation for generators operating in shunt excitation mode, where the exciter field is powered directly from the generator output terminals. The SSE‑N series is known for its reliability, simplicity, and adaptability to a wide range of generator sizes and applications.

Excitation Control Principle

The SSE‑N 125‑4.5KW operates by sensing the generator terminal voltage and comparing it against an internal reference setpoint. The regulator then adjusts the DC output to the exciter field winding, thereby controlling the generator field current and maintaining stable output voltage. This closed‑loop control system responds to load changes, speed variations, and power factor fluctuations to keep voltage within ±1% of the nominal setpoint.

Power Rating and Output Specifications

This model is rated for a continuous output of 125 V DC at 4.5 kW, making it suitable for medium‑sized shunt‑excited generators in the range of 50‑200 kVA. The regulator can provide a field forcing capability of up to 200% for short durations (typically 10 seconds) to support motor starting and other high‑inrush load events. The output is isolated from the input, ensuring safe operation and protection against ground faults.

Voltage Regulation Accuracy

The SSE‑N 125‑4.5KW achieves a steady‑state voltage regulation accuracy of ±0.5% from no‑load to full‑load, with a typical settling time of less than 0.5 seconds for a 10% step load change. The unit includes adjustable droop compensation (0‑5%) for parallel operation of multiple generators, allowing reactive power sharing without the need for external controllers. The regulation characteristics can be fine‑tuned using the front‑panel potentiometers for gain, stability, and droop.

Input Sensing and Protection

The regulator accepts single‑phase or three‑phase sensing inputs from the generator PTs (100‑480 V AC), with a frequency range of 45‑65 Hz. It is protected against reverse polarity, overvoltage, and transient surges on both the input and output sides. A built‑in over‑excitation protection circuit limits the output current to prevent damage to the exciter and generator field under fault conditions. The unit also includes a loss‑of‑sensing shutdown that safely de‑energizes the exciter if the sensing voltage is lost.

Adjustable Parameters and User Interface

Front‑panel controls include a voltage setpoint potentiometer, a stability adjustment, and a droop compensation trimmer. LED indicators provide status feedback for power, regulation active, and fault conditions. The unit also includes test points for monitoring the output voltage and current with a standard multimeter, facilitating troubleshooting and field calibration.

Mechanical and Environmental Design

Housed in a rugged steel enclosure for panel or wall mounting, the SSE‑N 125‑4.5KW is built to withstand harsh industrial environments. It operates over a temperature range of -20 °C to +60 °C and is rated IP20 for protection against solid objects. The unit is designed with natural convection cooling, eliminating the need for fans and improving long‑term reliability.

Typical Applications

This shunt exciter regulator is commonly used in diesel generators, hydroelectric plants, and industrial standby power systems. It is particularly suited for applications where a simple, cost‑effective excitation solution is required without the complexity of digital control. Its robust design makes it a popular choice for remote and off‑grid installations.

Installation and Wiring

Clear terminal markings and a comprehensive wiring diagram simplify installation. The unit requires connection to the generator PTs, the exciter field winding, and an auxiliary AC or DC supply. All terminals are rated for the full current and voltage capabilities, and the housing includes cable entry glands for secure wiring.

Compliance and Certification

The SSE‑N 125‑4.5KW complies with international standards for electrical safety and electromagnetic compatibility, including IEC 60034, UL 508, and CSA C22.2. It carries the CE mark and is designed to meet the requirements of marine and industrial classification societies.

Maintenance and Service Life

With solid‑state construction and no moving parts, the SSE‑N 125‑4.5KW offers a long service life and minimal maintenance requirements. Periodic inspection of connections and cleaning of the enclosure are recommended. Replacement parts, including potentiometers and fuses, are readily available from Basler Electric distributors.

Overall, the Basler Electric SSE‑N 125‑4.5KW shunt exciter regulator delivers reliable, accurate voltage control for shunt‑excited generators, making it an essential component for stable power generation.