# Performance Analysis of Quantum Key Distribution Technology for Power Business
## 5 Experimental Results  
Relying on the existing power network, this experiment established a verification environment by using QKD equipment, QVPNs and qualified fiber channels. Note that, actual business characteristics and information security requirements were considered. The test selects actual links to conduct business tests of dispatch automation, video consultation and data disaster recovery. Furthermore, the business performance tests of power distribution automation and power information collection are conducted in a simulated environment. As shown in Figure 11, the total length of the test line for the power dispatch automation industry was 142.82 km, with the measured attenuation of 53.76 dB. There are three types of the line environment used: DOFC, all-dielectric self-supporting optic fiber cable and OPGW. Due to the aging of the lines, the length and attenuation of DOFC was 43.94 km and 22.49 dB, respectively. The aerial part extends for 98.88 km, with the attenuation of 31.3 dB. The key negotiation between transmitter and receiver based on decoy-state BB84 QKD protocol [29]. The wavelength of quantum signals was 1550 nm. The transmitter and receiver are located in Headquarter A and substation G, respectively. Headquarter A was the National Power Dispatch Control Center (NPDCC) node and it was the dispatching automation master station. Node B was the centralized control node. Provincial company C was the Provincial Power Dispatching Control Center (PPDCC) point and it was the dispatching automation substation. Substation G was the power plant station. Headquarters node A, provincial node C and substation G form a three-level scheduling structure. A 2 Mbit/s channel was built through synchronous digital hierarchy (SDH) optical transmission system to realize the point-to-point interconnection of QVPN gateway of \"dispatching master station to substation\" and \"substation to plant station\" links. From substation G to provincial node C, there are three relay nodes, substation D, substation E and substation F. the whole network was composed of three levels of seven nodes. The test connects the remote host at the plant station end to the QVPN gateway for business traffic encryption and tunnels through the 2 Mbit/s channel. After reaching the remote QVPN gateway, the remote QVPN gateway decrypts it and forwards it to the target device to complete the transmission of QKD data for dispatching automation services. Figure 10: Disaster recovery backup based on QKD. The purpose of this test was to verify the performance of the QKD system for encrypted transmission of business instructions such as remote signaling, telemetry, remote control and remote adjustment. In the test, the main station, substation and remote control device were deployed at the National Power Dispatch Control Center point A, the Provincial Power Dispatching Control Center point C and power plant station point G and the terminal professional software was used to simulate the protection device to connect with the remote control device. The dispatching communication network port was connected to a quantum encryption VPN device to encrypt service data streams. The verification of the remote signaling, telemetry, remote control and remote adjustment services of the protection device and the main station/substation end was carried out. The telemetry service data at the plant end was taken from the real telemetry data in the station. Figure 12 shows the diagram of QKD-based dispatching automation test. The RTU (original production system) sends the remote signal and telemetry information in the station to the provincial dispatching automation system and the mobile master station (substation). Then, the telemetry and telemetry information received by the dispatching automation system and mobile master station (substation) are compared for consistency.