Most people think that it's after their performance review is complete. There's a better time to ask for a raise or promotion and it can significantly increase the chances of you getting more of what you want.
Ask for a raise or promotion prior to the fiscal year budget being set.
Most companies operate with a fiscal year budget. In simple terms, it's the time of year when the company sets their budget for the upcoming year. This doesn't always align with the calendar year. An example is the fiscal budget starts in September, so this means the budget for the year 2020 started in September 2019. Okay, so now that we've covered that here's the next step...
Have a conversation (negotiation is a conversation, not a battle) with your supervisor expressing how you're adding value and how you envision continuing to exceed expectations moving forward. In that conversation, you should share highlights of you work and ask for a raise or promotion.
The key points here are:
Understand when the fiscal year budget is set
Articulate the value you add
Express your plan to continue to go above & beyond