A comparison on the Perkins PK404D-22 Diesel Engine (Tecnogen PK23T/4SX GenSet)

RFL alternators

The RF series Radial Flux Generators are of a single stator, single rotor permanent magnet design. The combination of novel winding techniques with innovative rotor and stator design gives the RF series significant advantage over current commercially available technologies.

The RF series generators are designed specifically to be compact, lightweight whilst remaining highly efficient. All materials used in construction are conventional, so as to minimize manufacturing cost whilst still providing the specified performance.

The RFL RF4-160-130/134 is a technologically advanced PM brushless alternator, offering highest energy efficiencies while maintaining minimal physical size sets a new industry standard. Its PM design and natural electronic regulation means that possible points of failure are kept to a minimum by eliminating traditional brushes and AVRs.

The Leroy Somer LSA40 M5 Alternator was chosen as a comparison point for its similar high efficiency, brushless design. Tests results of fuel economy, motor starting capabilities and other physical factors were analysed and the RFL alternator was found to be superior in most aspects.


Comparison Chart

Physical Comparisons

Electronic comparison

Length Comparison

Visual comparison

Electronics Comparison

Fuel/Performance Results

Alternator – Leroy Somer LSA40M5 C 6/4

Engine – Perkins PK404D-22

table 1

Alternator – RFL RF4-160-130/134

Engine – Perkins PK404D-22

table 2

Running cost savings**

table 3

*Maximum power of RFL alternator is 1240 Watts extra

comparison chart

Table 4 – Graphical representation of Table 1 & 2

Electronic speed control simulation with variable rpm control (Constant Voltage)

table 5

comparison chart

Table 4 – Graphical representation of Table 1 & 2

comparison chart of alternator performance

It can be seen that with the gen-set fitted with the RFL Alternator, the transient voltage excursions were much lower, especially the over voltage. Also the time taken to get the motor up to speed was lower for both the 5.5 Kw motor and the 9.2 Kw motor. Also the transient voltage drop was around 8% less.  If the time constant for under voltage was longer, then the get set fitted with the RFL alternator, would have started the 9.2 Kw motor.  The RFL Alternator has a short circuit current of 100 amps, Where the Leroy Somer is estimated to have a short circuit current of around 3 times full load (70 Amps).