## 5 Sgsf-064-1  
The Smart Grid Standard Forum (SGSF) in Korea has developed a standard for communication protocols between EVs and conductive DC chargers which is called SGSF-064-1. This standard is based on CAN and it adopted the basic idea of the CHAdeMO (CHarge de MOve) which is a quick charging method proposed by The Tokyo Electric Power Company and other five Japanese automobile manufacturers. It was updated in June of 2014 to elaborate the process to avoid the charging error that the previous standard SGS-03-001 had. The standard document consists of seven sections: scope, normative references, definitions, system components, interface circuit and requirements, charging processes, and fault diagnosis. * Scope shows that this standard defines the communication protocol between EV and EVSE with IEC 61851 and IEC 61851-23. * Normative references reveal other standards which are indispensable for the application of these documents. They include ISO 11898-1/2, SGS 03-003, and IEC 61851-1/23/24. * Key terminologies used in the document are listed in the section of definitions. * System components detail the physical connection and equipment necessary for EV charging in DC mode. Among them are circuit breaker, current limiter, electric ground, circuit for coupler locking, _etc_. * Interface circuit and requirements describes the pilot signal circuit, wake up signal circuit, and protocol for charging the controller. The latter part further details features provided during DC charging, the circuit for CAN communication, and OSI (Open Systems Interconnection) layers for DC charging. * The charging process can be classified into two cases according to how it is terminated: normal charging and abnormal charging. In the case of abnormal charging, the sequence leads to stopping charging before it is completed for several reasons. These faults can occur in either theEV or EVSE and they also can happen prior to or during charging, whereas normal charging takes place when it occurs as expected. This will be elaborated on later in this section. * Fault diagnosis is a major addition to the previous standard. This part includes 10 types of charger faults such as insulation fault, abnormal charge, wake up signal fault, pilot signal fault, and others. For each fault, the location of fault detection is identified whether it occurs in a vehicle or in a charger and the corresponding warning statement is also suggested. The objective of the conformance testing of SGSF-064-1 is to check whether EVs and EVSEs comply with the charging sequences described in the standard. Therefore, this document details the charging process and it is further divided into three stages: pre-charging process, charging in-process, and terminating the post-charging process. Terminating the charging sequence can be either normal or abnormal. The normal sequence occurs when the EV battery is fully charged--to be specific, it is about 80% charged. Another case is when the user pushes the stop button in the charger for some reason to end charging. Abnormal terminating charging sequences occur in several cases. When there is a fault either at the EV or EVSE, then the charging is terminated by following the EV fault or charger fault sequence. Sometimes abnormal terminating charging sequences can be initiated before charging by the request of the EV or EVSE. The charging connector cannot be unlocked due to its higher voltage condition, and it also leads to the abnormal terminating charging sequences. The flow diagram of a normal charging sequence is shown in Figure 2. On the top, the charger and vehicle indicate EVSE and EV, respectively. Each small box represents the action of each entity and solid arrows represent wired communication while broken arrows represent CAN communication. Time T shown on the left or right next to a vertical line with an arrow at both ends indicates the time limit for the task. If it is not finished in that period, then it is regarded as an error. In Figure 2, there are three stages in SGSF-064-1.