diff --git a/open-reac/src/main/java/com/powsybl/openreac/parameters/input/OpenReacParameters.java b/open-reac/src/main/java/com/powsybl/openreac/parameters/input/OpenReacParameters.java
index dcb5f842..005f6396 100644
--- a/open-reac/src/main/java/com/powsybl/openreac/parameters/input/OpenReacParameters.java
+++ b/open-reac/src/main/java/com/powsybl/openreac/parameters/input/OpenReacParameters.java
@@ -216,6 +216,17 @@ boolean checkVoltageLevelLimits(Network network) {
             double lowLimit = vl.getLowVoltageLimit();
             double highLimit = vl.getHighVoltageLimit();
 
+            if (lowLimit <= 0) {
+                List<VoltageLimitOverride> overrides = getSpecificVoltageLimits(vl.getId(), VoltageLimitOverride.VoltageLimitType.LOW_VOLTAGE_LIMIT);
+                if (overrides.size() != 1) {
+                    LOGGER.warn("Voltage level {} has a negative or null low voltage limit. Please change it or use a voltage limit override.", vl.getId());
+                    integrityVoltageLevelLimits = false;
+                } else if (overrides.get(0).isRelative() && overrides.get(0).getLimit() + lowLimit <= 0) {
+                    LOGGER.warn("Voltage level {} has a negative low voltage limit, even taking into account voltage limit override.", vl.getId());
+                    integrityVoltageLevelLimits = false;
+                }
+            }
+
             if (Double.isNaN(lowLimit)) {
                 List<VoltageLimitOverride> overrides = getSpecificVoltageLimits(vl.getId(), VoltageLimitOverride.VoltageLimitType.LOW_VOLTAGE_LIMIT);
                 if (overrides.size() != 1) {
diff --git a/open-reac/src/main/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInput.java b/open-reac/src/main/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInput.java
index c51c79dc..6748b461 100644
--- a/open-reac/src/main/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInput.java
+++ b/open-reac/src/main/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInput.java
@@ -10,7 +10,6 @@
 import com.powsybl.ampl.executor.AmplInputFile;
 import com.powsybl.commons.util.StringToIntMapper;
 import com.powsybl.iidm.network.Network;
-import com.powsybl.openreac.parameters.AmplIOUtils;
 import org.jgrapht.alg.util.Pair;
 
 import java.io.ByteArrayInputStream;
@@ -82,7 +81,7 @@ public InputStream getParameterFileAsStream(StringToIntMapper<AmplSubset> string
 
             if (!Double.isNaN(limits.getFirst()) || !Double.isNaN(limits.getSecond())) {
                 int amplId = stringToIntMapper.getInt(AmplSubset.VOLTAGE_LEVEL, voltageLevelId);
-                String[] tokens = {Integer.toString(amplId), Double.toString(limits.getFirst()), Double.toString(limits.getSecond()), AmplIOUtils.addQuotes(voltageLevelId)};
+                String[] tokens = {Integer.toString(amplId), Double.toString(limits.getFirst()), Double.toString(limits.getSecond()), "\"" + voltageLevelId + "\""};
                 dataBuilder.append(String.join(" ", tokens));
                 dataBuilder.append(System.lineSeparator());
             }
diff --git a/open-reac/src/test/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInputTest.java b/open-reac/src/test/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInputTest.java
index 1011eef0..c36dbd08 100644
--- a/open-reac/src/test/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInputTest.java
+++ b/open-reac/src/test/java/com/powsybl/openreac/parameters/input/VoltageLevelLimitsOverrideInputTest.java
@@ -49,7 +49,7 @@ void testValidRelativeVoltageOverride() throws IOException {
         try (var is = input.getParameterFileAsStream(mapper)) {
             String data = new String(ByteStreams.toByteArray(is), StandardCharsets.UTF_8);
             String ref = String.join(System.lineSeparator(), "#num minV (pu) maxV (pu) id",
-                    "1 0.7916666666666667 1.1666666666666665 'VLGEN'") + System.lineSeparator() + System.lineSeparator();
+                    "1 0.7916666666666667 1.1666666666666665 \"VLGEN\"") + System.lineSeparator() + System.lineSeparator();
             assertEquals(ref, data);
         }
     }
@@ -73,11 +73,31 @@ void testValidAbsoluteVoltageOverride() throws IOException {
         try (var is = input.getParameterFileAsStream(mapper)) {
             String data = new String(ByteStreams.toByteArray(is), StandardCharsets.UTF_8);
             String ref = String.join(System.lineSeparator(), "#num minV (pu) maxV (pu) id",
-                    "1 0.8333333333333334 1.0833333333333333 'VLGEN'") + System.lineSeparator() + System.lineSeparator();
+                    "1 0.8333333333333334 1.0833333333333333 \"VLGEN\"") + System.lineSeparator() + System.lineSeparator();
             assertEquals(ref, data);
         }
     }
 
+    @Test
+    void testNullVoltageLimitWithoutOverride() {
+        Network network = IeeeCdfNetworkFactory.create118();
+        setDefaultVoltageLimits(network); // set default voltage limits to every voltage levels of the network
+
+        VoltageLevel vl = network.getVoltageLevels().iterator().next();
+        OpenReacParameters params = new OpenReacParameters();
+
+        // if one low voltage limit is <= 0 and there is no voltage limit override, invalid OpenReacParameters
+        vl.setLowVoltageLimit(0);
+        assertThrows(PowsyblException.class, () -> params.checkIntegrity(network));
+
+        // if one low voltage limit is <= 0 and the voltage limit override is not enough, invalid OpenReacParameters
+        List<VoltageLimitOverride> overrides = new ArrayList<>();
+        overrides.add(new VoltageLimitOverride(vl.getId(), VoltageLimitOverride.VoltageLimitType.LOW_VOLTAGE_LIMIT,
+                true, 0));
+        params.addSpecificVoltageLimits(overrides);
+        assertThrows(PowsyblException.class, () -> params.checkIntegrity(network));
+    }
+
     @Test
     void testUndefinedVoltageLimitsWithoutOverride() {
         Network network = IeeeCdfNetworkFactory.create118();