Modification of test measurement signals for protective devices for electric power networks

An adapter apparatus for modifying test measurement signals for protective devices, including a first protective device and a second protective device, in electric power networks, the adapter apparatus comprising:

• an input interface configured to receive a first test measurement signal, the first test measurement signal being matched to a first electrical input characteristic of the first protective device for a power network, wherein said input interface having an input voltage connection;
• an electrical modification system coupled to said input interface to convert the first test measurement signal into a second test measurement signal, the second test measurement signal being matched to a second electrical input characteristic of the second protective device for the power network, wherein said electrical modification system having a circuit to emulate an electric field probe, wherein said circuit to emulate the electric field probe having a capacitor configuration with at least two capacitors, and a capacitor selector which is connected in series with said capacitor configuration between said input interface and said output interface, said capacitor selector is configured to modify an effective capacitance of said capacitor configuration between said input interface and said output interface through a targeted activation or deactivation of a capacitor;
• and
• an output interface to output the second test measurement signal to the second protective device, said output interface having an output voltage connection.

A system for modifying a plurality of test measurement signals for protective devices, including a first protective device and a second protective device, in electric power networks, the system comprising:

• a plurality of adapter apparatuses for modifying test measurement signals for the protective devices in the electric power networks, said adapter apparatuses each containing:
• an input interface configured to receive a first test measurement signal, the first test measurement signal being matched to a first electrical input characteristic of the first protective device for a power network;
• an electrical modification system coupled to said input interface to convert the first test measurement signal into a second test measurement signal, the second test measurement signal being matched to a second electrical input characteristic of the second protective device for the power network;
• an output interface to output the second test measurement signal to the second protective device;
• and
• a temperature sensor emulation circuit configured to generate an emulated test temperature measurement signal and transmit it to said output interface, wherein an electrical output characteristic of said temperature sensor emulation circuit simulates an electrical output characteristic of a real temperature-measuring device.

A method for modifying test measurement signals for protective devices in electric power networks using an adapter apparatus containing an input interface, an electrical modification system coupled to said input interface, and an output interface, which method comprises the steps of:

• feeding a first test measurement signal from a test generator to the input interface of the adapter apparatus, the first test measurement signal is matched to a first electrical input characteristic of a first protective device for a power network;
• converting the first test measurement signal into a second test measurement signal using the electrical modification system coupled to the input interface, the second test measurement signal is matched to a second electrical input characteristic of a second protective device for the power network;
• generating an emulated test temperature measurement signal, via a temperature sensor emulation circuit, and transmitting the emulated test temperature measurement signal to the output interface, wherein an electrical output characteristic of the temperature sensor emulation circuit simulating an electrical output characteristic of a real temperature-measuring device;
• and
• outputting the second test measurement signal to the second protective device via the output interface of the adapter apparatus.