China’s BYD having risen over the past decade to become one of the top global sellers of electric passenger cars, is now plotting a big push into battery-electric commercial vehicles. Over the next three years, BYD plans to introduce new commercial-vehicle models in markets including China, Europe and Japan, according to people familiar with the company’s plans. It has mapped out a budget of more than $20 billion for its commercial-vehicle unit through 2025, with major outlays planned for research, product development and expansion of production capacity, the people said.