GEAR 1S1747 - Caterpillar

Integrated Voltage Regulator (IVR) General Information
The EMCP integrated voltage regulator (IVR) feature is a substitute for a traditional voltage regulator configuration. The traditional voltage regulator configuration consists of a dedicated controller such as a Cat Digital Voltage Regulator (CDVR) or a VR6.The EMCP 4 internal controller regulates generator output voltage. The voltage is regulated by sending a command to the excitation module (EM10/EM15). The excitation module controls generator excitation and therefore generator output voltage.The IVR feature is available with revised EMCP 4.2 controllers with software version 4.3PROD and above. The capability does NOT exist in original EMCP 4.2 controllers, regardless of software version.
Illustration 1 g03486261
EMCPintegrated voltage regulator (IVR) system
IVR Features for EMCP 4.2
The following functionality is available when an EMCP 4.2 possesses IVR logic and is used with an excitation module (EM):
Automatic voltage regulation (AVR)
Programmable stability settings
Soft start control with an adjustable time setting in AVR control mode
Dual slope, under frequency (Volts/Hz) regulation that can be configured
Three-phase or single-phase generator voltage (RMS) sensing/regulation in AVR mode
Set point configuration adjustment from the EMCP display or Cat® Electronic Technician (Cat ET) Service Tool
Voltage output adjustment via display, analog input, digital input, or SCADA (Modbus)
IVR operating status and voltage bias overview screens to provide an enhanced level of user interface
Integrated voltage regulator event monitoring
Power factor regulation (PF) (EMCP 4.2 only)
Reactive droop compensation (EMCP 4.2 only)
Line drop compensation (EMCP 4.2 only)Hardware Installation
EMCP IVR Connections
To regulate the generator terminal voltage, the EMCP communicates the desired excitation command to the excitation module via a pulse width modulation PWM signal. A twisted pair shielded cable must be used for the communication link. Table 1 details the connections to be made between the EMCP and excitation module.
Table 1
EMCP 4.2 Connections to Excitation Module
EMCP 4.2 70-Pin Connector Excitation Module 3-Pin Connector
Digital Output #2 / IVR CS+ 68 CS+ P3-2
Battery negative splice 60 or 65 CS- P3-3
Battery negative splice 60 or 65 Shield P3-1 IVR Excitation Module
The IVR consists of an EMCP 4 that is interface with an excitation module.
Illustration 2 g03487518
EM10 and EM15 excitation modules
Table 2 provides information on the technical specification of the EM10 and EM15 modules. Selection of the appropriate module must be determined by the following:
Nominal and maximum generator excitation current at full load (standby, 0.8PF)
The maximum AC voltage input
Table 2
EM10 and EM15 Technical Specifications
EM10 EM15
Compatible Generator Excitation Types Permanent Magnet (PM)
Self-Excitation (SE)
Internal Excitation (IE/AREP)(1)
Nominal Field Current Output 6 A 7 A
Maximum (forcing) Field Current Output 10 A 15 A
Maximum AC Voltage Input 180 Vrms 240 Vrms
Exciter Field Resistance (recommended) 6 to 16 ohms
(1) Internal Excitation (IE is also referred to as "Auxiliary Regulation Excitation Principle" (AREP).Details for nominal field current are available on the generator data sheet. For self-excited (shunt) generators, users must understand the connections between the generator winding and the excitation module to understand the maximum AC voltage input. Caterpillar recommends that an intermediate, half-phase to neutral connection be used for self-excited generators.IVR Excitation Module Physical Layout
The recommended location for the excitation module is in the generator set control panel or the generator terminal