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Excitation System of Leroy-Somer Alternator AVR R450

1.1 - Description

The R450 AVR is supplied in a casing designed to be mounted on a panel with dampers.

- Operating temperature: - 30°C to + 65°C.

- Storage temperature: - 55°C to + 85°C.

- Shocks on the base: 9 g depending on the 3 axes.

- Vibrations: less than 10 Hz, 2 mm half-peak amplitude 10 Hz to 100 Hz: 100 mm/s, above 100 Hz: 8 g.

The AVR is IP00, it must be incorporated in an environment which ensures it a IP20 protection.

1.2 - Characteristic

The connection is realised by “Faston” connectors and the voltage sensing is single - phase.

2 - POWER SUPPLY

Both the SHUNT/AREP & PMG excitation systems are controlled by the AVR.

2.1 - AREP excitation system

With AREP excitation, the electronic AVR is powered by two auxiliary windings which are independent of the voltage sensing circuit.

The first winding has a voltage proportional to the alternator main voltage (Shunt characteristic), the second one has a voltage proportional to the stator current (compound characteristic : Booster effect).

The power supply voltage is rectified and filtered before being used by the AVR monitoring transistor.

This system provides the machine with a short-circuit current capacity of 3 IN for 10 s. The rotating switch should be in the AREP position (see 3.2.3).

2.2 - PMG excitation system

With PMG excitation, a permanent magnet generator (PMG) added to the alternator supplies the AVR with voltage which is independent of the main alternator winding.

This system provides the machine with a short-circuit current capacity of 3 IN for 10 s.

The AVR monitors the alternator output voltage by adjusting the excitation current. The rotating switch should be in the PMG position (see 3.2.3).

2.3 - SHUNT or separate excitation system

With SHUNT excitation, the AVR is powered by the main winding (100V to 140V -50/60 Hz ) by using X1, X2 on the AVR. The rotating switch should be in the SHUNT/ AREP position (see 3.2.3).

3 - TECHNICAL CHARACTERISTICS

3.1 - Electrical characteristics

- maximum power supply: 150V - 50/60 Hz

- Rated overload current: 10 A - 10 s

- Electronic protection:

- In the case of a short-circuit, the excitation current is reduced to a value less than 1A after 10 s

- In the event of loss of voltage reference, the excitation current is reduced to a value less than 1A after 1s for AREP/SHUNT, 10 s for PMG.

- In the event of overexcitation, the current is reduced as indicated in the next diagram (see 3.2.1.4).

- Fuses: F1 on X1 and F2 on Z2 10A, 250V.

- Voltage sensing

• 0-110 V terminals = 95 to 140 V

• 0-220 V terminals = 170 to 260 V

• 0-380 V terminals = 340 to 528 V

For other voltages, a transformer should be used.

- Voltage regulation:± 0.5%.

- Current sensing: (parallel operation): input S1, S2 intended for 1 C.T. < 2.5 VA cl1, secondary 1 A or 5 A.

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