High voltage alarm (ID 2034): OV limit, HVRT, Q-U curve

Problem description

The Grid Overvoltage alarm (ID 2034)  often occurs during the day:

Possibble causes:

The grid voltage exceeds the higher threshold or the high voltage duration has lasted for more than the value specified by HVRT.

1. Cross-section of the AC line is insufficient
   Check the cross-section and all contacts near the inverter and distribution board. Turn off the inverter and measure voltage on the inverter AC terminal and on other end of the cable line in the distribution box.
2. Bad contacts in the point of connection in distribution box or on the inverter AC terminals.
   Check the circuit breaker terminals, inverter terminals and if possible measure temperature of connection points with thermal camera. Please, note that using cable lugs with different material from the cable leads to corrosion and it can cause bad contact.
3. Hight voltage in the grid due to many solar plants connected to the same transformer
   Contact your grid operator to regulate the voltage on the transformer.
4. Low thresholds of the HVRT and OV protection.
   You can modify the settings in the inverter. Follow steps next steps.
   NOTE:
   Changing this values without grid operator premission can cause damage of other equipment connected to the same grid.

Prerequisites

You have logged in under installer account.

Procedure

1. Choose Plants > Device > Device Management
   
2. Select the Plant, mark the Inverter > click Set Parameters
3. Go to Protection parameters > change 10 minute OV protection threshold (V) to bigger value > Set
4. Go to Feature parameters and if the HVRT set to Enable > change HVRT trigger threshold (V) to bigger value > click Set

Or you can activate reactive power generation function as well when the grid voltage starts to raise. Please follow next steps to do it:

NOTE:
Changing these settings can lead to unstable grid working. Please, change this values only after operator permitted this changes with specific values.

1. Go to Power Adjustment > set the Reactive power curve adjustment to the Q-U characteristic curve
2. Set the Number of Q-U characteristic curve points to 6 > adjust values of these six points below if needed > click Set