Re: hev

[Lee Hart <leeahart@earthlink.net>]

krishnaswamy nathan wrote:
> 
> * LP8.2: HTML/Attachments detected, removed from message  *

krishna,

You need to set your email software to send plain text to post to the EV
list. Otherwise, your message is removed and the above message is all
that appears.

In a series hybrid with a battery between the generator and motor, you
need one controller for the generator, and one for the motor.

If your motor is a series DC motor, then its motor controller can be as
simple as a contactor controller. This is just a bunch of big switches
or relays and power resistors. It controls motor speed by switching in
series resistors, or switching the batteries in various series/parallel
combinations, or using two motors and switching them in series/parallel,
or using a motor with a tapped series field and switching taps.

A more expensive but better method is to use a PWM controller, as made
by made by Curtis, Zapi, Sevcon, 4QD, and other companies. It works like
a big light dimmer, stepping the battery voltage down (and the current
up) to control the motor.

The generator controller for a separately excited DC generator is pretty
easy. You control the field current to control the generated voltage and
current. The simplest controller is simply that from any normal car or
truck; it controls the generator or alternator field current to regulate
the battery at some fixed voltage. You can copy the circuit or modify
one for whatever your battery voltage is.

The generator will also act as a motor (draws battery power to spin the
engine) if the engine runs out of gas or tries to turn slower than the
generator. You can use this as a starter. If you don't want this
behaviour, you need control circuits or a big diode.
-- 
Lee A. Hart                Ring the bells that still can ring
814 8th Ave. N.            Forget your perfect offering
Sartell, MN 56377 USA      There is a crack in everything
leeahart_at_earthlink.net  That's how the light gets in - Leonard Cohen