©　2018　Chin.　Soc.　for　Elec.　Eng.　The　combined　array　sensor　was　studied　which　consists　of　a　cross-shaped　ultrasonic　array　with　25　elements　and　an　UHF　array　with　2×2　elements.　Algorithms　for　location　based　on　the　combined　array　were　studied,　which　achieved　the　virtual　expansion　of　193　and　13　elements　of　the　two　arrays　respectively.　Two-sided　correlation　transformation　(TCT)　based　on　the　UHF　array　was　employed　to　estimate　the　PD＇s　direction,　and　then　the　rotated　signal　sub-space　(RSS)　based　on　ultrasonic　was　used　for　accurate　direction.　To　improve　the　success　rate　and　accuracy　of　a　single　array　in　PD　positioning,　taking　the　UHF　signal　as　example,　the　ray　tracing　technique　based　on　geometrical　optics　(GO)　and　uniform　geometric　diffraction　(UTD)　was　used　to　study　the　inversion　of　the　electromagnetic　wave　trajectory　of　PD.　The　experiments　of　partial　discharge　positioning　in　the　transformer　model　indicates　that　the　position　algorithm　based　on　the　combined　array　sensor　has　a　good　adaptability　to　the　wideband　signal　generated　by　PD　and　the　tracing　inversion　of　the　PD　radiation　electromagnetic　wave　makes　the　position　accuracy　and　the　success　rate　much　greater　than　the　results　of　a　single　array,　namely　the　combined　array　demonstrates　the　advantages　of　the　high　sensitivity　of　UHF　arrays　and　the　high　accuracy　of　ultrasonic　arrays.