1、 SURFACE VEHICLE RECOMMENDED PRACTICE Voltage Regulators for Automotive-Type Generators SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability a
2、nd suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestion
3、s. Copyright 2006 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOC
4、UMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: custsvcsae.org SAE WEB ADDRESS: http:/www.sae.org Issued 2006-01 J2669 ISSUED JAN2006 1. Scope This SAE Definition Document contains historic voltage regulation methods and test requiremen
5、ts that have not been previously published. The purpose of this document is to recommend a set of definitions and practices for use on current and future 12 V vehicle electric power regulation and control systems in internal combustion engine road vehicles. This document is not intended to include n
6、or exclude regulators used in higher voltage vehicle electrical systems. The term “generator” rather than “alternator” will be used even though these terms may be used interchangeably in practice. 1.1 Rationale This recommended practice has been developed to reduce the worldwide variation in regulat
7、ion methods used on automotive generator systems. 2. References 2.1 Applicable Publication The following publication forms a part of this specification to the extent specified herein. Unless otherwise indicated, the latest version of SAE publications shall apply. 2.1.1 SAE PUBLICATION Available from
8、 SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J2232Vehicle System VoltageInitial Recommendations Information Report SAE J2669 Issued JAN2006 - 2 - 2.2 Related Publications The following publications
9、are provided for information purposes and are not a required part of this document. 2.2.1 SAE PUBLICATIONS Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J56Road VehiclesAlternators with
10、 RegulatorsTest Methods and General Requirements Abstract: This SAE Standard specifies test methods and general requirements for the determination of the electrical characteristic data of alternators for road vehicles. It applies to alternators, cooled according to manufacturers instructions, mounte
11、d on internal combustion engines. This document attempts to follow ISO 8854, dated 1988. ISO 8854 has been modified herein to reflect local market requirements and historical precedent. SAE J1416Generator Terminal Labeling SAE J831Electrical Definitions 3. Definitions 3.1 Nominal Voltage The charact
12、eristic voltage of a vehicles electrical storage system. It is equal to the nominal voltage of the battery used (i.e., 12 V, 24 V, 36 V). (Definition per ISO/TC22/SC3 N1057) 3.2 Working Voltage The nominal output voltage of the vehicles generator, under normal typical conditions (i.e.14 volts for a
13、12-volt battery, 28 volts for a 24-volt battery, 42 volts for a 36-volt battery, etc) and is the vehicles nominal battery charging voltage, as described in J2232. 3.3 Supply Voltage The variable voltage of the electrical system of a vehicle depending on the system load and the operating condition of
14、 the generator and battery. (i.e., 8 V to 18 V.) (Definition per ISO SC3 proposal dated Feb. 2001). 3.4 Ripple Voltage Peak-to-peak AC voltage component of the supply voltage. 3.5 Regulator A device that controls the output of a generator to maintain a desired voltage. The regulators described in th
15、is document achieve this by controlling the generator field current. SAE J2669 Issued JAN2006 - 3 - 4. Definitions of Functions Pertaining to the Control and/or Behavior of the Generator Voltage Regulator (See Figures 1 and 2 for typical system wiring diagrams.) 4.1 Initialization, Start Up, and Dea
16、ctivation 4.1.1 EXTERNAL INITIALIZATION (POWER UP) An external signal can be sent to enable the regulator electronics after a vehicles ignition or start switch is turned on. The signal can be provided prior to or after the engine has been started. This signal can be directly from the ignition switch
17、, or it can be provided via an external controller such as the Powertrain Control Module (PCM, LIN, BSS, etc.). This might be a switch used to energize portions of the regulator circuit and/or generator mechanism, or an analog or digital input signal to the control circuits of the regulator. This is
18、 also the point of operation where the warning lamp should be illuminated by the regulator or by an external controller. Example of ignition voltage threshold: 1 V Example of external controller threshold: First transition to dominant state 4.1.2 SELF INITIALIZATION The regulator can be designed to
19、self-initialize the generator when the machine is spinning above a specified threshold. The regulator can detect the small signal voltage waveform generated at the stator phase input due to residual magnetism or permanent magnets in the rotor circuit. This condition causes the regulator to initializ
20、e and activate the field at an initially low excitation level (sometimes called pre-excitation duty cycle) until a sufficient stator signal has been generated such that the regulator can begin normal field circuit control. This feature can be used in place of an external initialization signal or in
21、the event of an external initialization fault. Example of initial field control duty cycle = 0% to 30% 4.1.3 EXTERNAL FIELD CIRCUIT ACTIVATION (FIELD OPERATION THRESHOLD) The point at which an external controller determines that specific system requirements have been satisfied and a signal is sent t
22、o the regulator initializing field circuit activation and control. Once this signal is received, the regulator can immediately initiate “soft start” or closed-loop voltage regulation in order to achieve and maintain the generator working voltage. 4.1.4 INTERNAL FIELD CIRCUIT ACTIVATION (FIELD OPERAT
23、ION THRESHOLD) The point at which the regulator determines that the generator is spinning at a sufficient speed such that soft-start (see 4.1.5) or closed-loop voltage regulation can be initiated. SAE J2669 Issued JAN2006 - 4 - 4.1.5 SOFT-START Describes a regulator initialization control strategy t
24、hat limits the generators torque load applied to the vehicles engine during engine start. This is achieved by holding the field current at a low level to allow generator excitation but preventing excessive torque during engine crank and engine run-up. When the regulator detects that the engine speed
25、 is above a specific threshold, the field current (duty cycle) is ramped at a fixed rate until voltage regulation is achieved (typically greater than 10% and less than 100% per sec. An external controller can also act to control the regulator ramp function.) The soft start may occur after a delay ti
26、me. Example of minimum speed threshold = 1200 generator RPM Example of soft-start ramp rate = + 20% duty cycle/second Example of soft start delay time: 0.2 s to 15 s 4.1.6 EXTERNAL DEACTIVATION In an externally initializing system, the regulation function is deactivated when the external signal is r
27、emoved. In most cases, this occurs when the ignition or start switch is turned to the off position. 4.1.7 SELF DEACTIVATION In a self-initializing system, the regulation function is deactivated when the generator stops rotating. Deactivation results in the regulator reverting to minimum quiescent cu
28、rrent drain (sleep mode). 4.2 Load Response Control (LRC) 4.2.1 INCREASING ELECTRICAL LOAD AT LOW ENGINE SPEED A field duty cycle ramp rate limit is applied when an electrical load is activated in a vehicle operating at low engine speeds such that the generator output must increase to maintain the r
29、equired system voltage. The linear ramp-up function provides a gradual, rather than instantaneous, generator torque loading of the engine. The field current is ramped up at a limited rate until voltage regulation is achieved. The gradual increase in applied generator torque prevents the engine idle
30、speed from dropping due to a sudden increase in torque load that can lead to Noise, Vibration and Harshness (NVH) issues and possible engine stall. Typical maximum speed threshold below which LRC is enabled = 3000 generator RPM Typical ramp rate = + 20% duty cycle/second 4.2.2 DECREASING ELECTRICAL
31、LOAD No ramp down function is employed for the decrease in field duty cycle. The voltage regulator must instantly react to decreasing electrical load by decreasing the field current in order to prevent the regulated voltage from increasing to unacceptable levels. SAE J2669 Issued JAN2006 - 5 - 4.3 V
32、oltage Sensing and Diagnostics 4.3.1 GENERATOR VOLTAGE SENSING The regulator can sense the voltage directly at the internal rectifier output of the generator for the purpose of regulating the voltage and detecting generator output fault conditions 4.3.2 BATTERY VOLTAGE SENSING A dedicated sense line
33、 can be connected between the battery positive terminal and the generator regulator connector for the purpose of accurately sensing the battery voltage with respect to the regulator ground reference. This practice is recommended in vehicles where excessive voltage drop between the generator output a
34、nd the battery terminations can lead to incorrect voltage regulation. Typically, if this signal is missing, the regulator will revert to generator voltage sensing and a fault may be indicated. 4.3.3 DIODE TRIO VOLTAGE SENSING One variation of generator regulators employs a diode trio as shown in Fig
35、ure 3. The diode trio output is designated “D+” and it provides bias for the generator field current circuit as well as a voltage sensing input to the regulator. The D+ signal is a full wave rectification of the generator output independent of the rectification that supplies the generator main outpu
36、t. The signal is live only when the generator is producing power, and the signal voltage is equal to the generators regulated output voltage. The D+ signal powers the generators field and provides a means to control the vehicle charge warning light. An over-voltage cutoff (OVCO) circuit used with a
37、D+ powered field requires interrupting the D+ to the field with a switching circuit. The D+ circuit is sometimes used to power an external load or activate and external relay after the generator becomes operational. Excess external load on D+ circuit may exceed the D+ rectifier diode rating and fail
38、 the generator field circuit. 4.3.4 OVER-VOLTAGE CONDITION AND RESPONSE Over-voltage can occur due to one of the following reasons: a shorted field driver, a short in the generator that results in unregulated field current, a corrupted voltage sense input, load dump (load shedding), or jump start. T
39、he over-voltage fault threshold is normally set at a level below the voltage at which potential electrical system damage could occur. The fault can be detected either at the battery sense input (if used) or the generator sense input. Additionally, a fault can be detected via the voltage difference b
40、etween these two circuits. The over-voltage condition can exist for a specified time prior to indicating a fault condition. The fault indication can be turned off after the voltage falls below the over-voltage threshold by a specified value. The field driver duty cycle should be reduced to 0% as qui
41、ckly as possible when an over-voltage condition is detected. The regulator may turn the field driver back on if/when the voltage level returns to a normal operating range. Optionally, a secondary control circuit can be used to interrupt the field current in the event of a short that results in unreg
42、ulated field current. If a secondary control circuit disables generator operation by interrupting the field circuit, the voltage detection circuit will need to be reset. Reset may take place by cycling the ignition or when the voltage falls below a specified threshold. SAE J2669 Issued JAN2006 - 6 -
43、 Load dump events create significant over-voltage conditions in a charging system. The regulator should turn the field driver off as quickly as possible in the event of an over-voltage condition in order to minimize the voltage and duration of the load dump event. In addition, secondary circuits can
44、 be used to bring the field current to zero as quickly as possible. One example of a secondary circuit within the regulator utilizes high re-circulation voltage to achieve fast field quenching. Secondary circuits can also be used within the generator to clamp the load dump voltage. For additional tr
45、ansient voltage information, please see the documents referenced in section 4.11.8. Typical time delay for fault indication: 1 second to 3 seconds Typical threshold to turn off fault indication: 0 V to 0.5 V below the over-voltage threshold Typical time delay for secondary control circuit: 3 seconds
46、 Typical threshold to turn off secondary control circuit: 20% below the normal setpoint voltage 4.3.4.1 Fixed Threshold The over-voltage threshold can be a fixed value over temperature. Typical fixed over-voltage threshold: 16 V. 4.3.4.2 Set Point-Dependant Threshold The over-voltage threshold can b
47、e a fixed percentage (or differential) above the set point voltage. Typical set point-dependant threshold: 8% to 13% above Setpoint 4.3.5 VOLTAGE DIFFERENTIAL BETWEEN GENERATOR SENSE AND BATTERY SENSE An over-voltage condition can be detected if the generator sense input exceeds the battery sense in
48、put by a specified value when the battery sense input is within its normal operating range. This over-voltage detection mode is used to detect either excessive resistance in series with the battery sense input or a generator B+ open circuit condition. Typical voltage differential threshold: 1 V to 3
49、 V 4.3.6 UNDER-VOLTAGE DETECTION AND RESPONSE SYSTEM VOLTAGE SENSING Under-voltage detection is typically a generator speed dependant threshold set at a fixed value over temperature. The speed dependency helps prevent unwarranted warning lamp illumination at low speeds where the electrical load demand may exceed generator output capability. The under-voltage condition can exist for a specified time prior to indicating a fault condition. The fault indication can be turned off after the voltage rises above the undervoltage threshold by a specified value. T
