Xantrex Technology PV-225208 Section Operation, Operation Features, Active Island Detection

SECTION 4

OPERATION

The user should be aware of the following conditions governing PV-225208 state transitions:

•Utility power must be present for all states of operation.

•Fault states are automatic from any state of operation. A fault will cause the PV-225208 to immediately stop processing all power. The fault condition will be reported to the operator interface LCD.

•Most PV-225208 faults are latching and must be cleared at the operator interface keypad before transitioning to another operating state.

•The On/Off switch, located on the front door of the PV-225208, must be in the On position for all operating states except Matrix Test, in which case it must be in the Off position.

OPERATION FEATURES

Fixed Unity Power Factor Operation

The Xantrex PV Series grid tied inverters maintain unity power factor during operation. The control software constantly senses utility voltage, and constructs the output current waveform to match the utility voltage. The PV line of inverters are not capable of operation without the presence of normal utility voltage, nor are they capable of varying the output power factor off unity.

Utility Voltage/Frequency Fault Automatic Reset

In the event of a utility voltage or frequency excursion outside of preset limits, the PV-225208 will stop operation and annunciate a fault at the operator interface. Once the utility voltage has stabilized within accept- able limits for a period of at least five minutes, the PV-225208 will automatically clear the fault and resume normal operation. Voltage and frequency fault setpoints are detailed later in this section.

Active Island Detection

Much concern has been given to the possibility of an inverter causing a ‘utility island’ condition during a utility power outage. An island condition is defined as grid tied inverter maintaining operation and supporting a load that has been isolated from the utility power source. This requires the load to be closely balanced to the output power of the inverter as well as having a resonant frequency close to 60Hz. Needless to say, this is an extremely remote possibility. To insure this condition does not occur, the PV-225208 control software contains an active phase-shift-loop algorithm, which destabilizes a balanced load, which may otherwise be capable of maintaining inverter operation in the absence of utility voltage. This feature has been extensively tested and proven to exceed the safety requirements of UL-1741 and IEEE-929- 2000.

Ground Fault Detection

The PV-225208 is equipped with a ground fault detection circuit and current transducer. In the event of a 10 amp ground fault, the PV-225208 will execute an orderly shutdown and annunciates a ground fault at the operator interface. (See Section 5, Troubleshooting).

DOCUMENT: 151811	PV-225208 Photovoltaic Inverter	4-2
	Operation and Maintenance Manual

Copyright 2003, Xantrex Technology Inc.