代码运行没有报错，在运行一段时间后浏览器崩溃，具体代码如下：

carousel(){

    let self = this;
    if(!window.timer){
      this.carouselText = "结束轮巡";
      let oLen = this.substationTree.length;
      window.timer = setInterval(() => {
        self.carouselIndex = self.carouselIndex < oLen - 1 ? self.carouselIndex + 1 : 0;
        self.$set(self.substationTree[self.carouselIndex], 'selected', true);
        self.selectedNode = Object.assign({}, self.substationTree[self.carouselIndex]);
        self.clickOnTreeNode([self.substationTree[self.carouselIndex]]);
      }, 5000);
    }else {
      this.carouselText = "开始轮巡";
      window.clearInterval(window.timer);
      window.timer = undefined;
    }
  }