DETERMINING PRACTICAL PLANNING LIMITS FOR DG ON DISTRIBUTION CIRCUITS

It is expected that the amount of DG, particularly renewable DG, on distribution systems will increase with the development of the Smart Grid. Some utilities have already experienced operating problems with the voltage rise from large solar PV generation and have proposed tight limits. Distribution engineers are seeking practical methods to determine limits for DG that may be applied at the planning stage. Voltage criteria are often the best indicators of successful operation of proposed DG, but are not always easy to apply. There may not be sufficient headroom throughout the system to allow for the voltage rise from DG output. This paper describes our evaluation of planning methods proposed in the literature and from our own research. Capabilities of distribution system analysis tools to support DG limit evaluation are discussed.