It was another busy week for Australia's top brokers. This has led to the release of a number of broker notes.

Three broker buy ratings that you might want to know more about are summarised below. Here's why brokers think these ASX shares are in the buy zone:

Beach Energy Ltd (ASX: BPT)

According to a note out of Bell Potter, its analysts have retained their buy rating on this energy producer's shares with an improved price target of $1.50. Bell Potter was pleased with the company's performance during the last quarter. It notes that production, sales volumes, and revenue all comfortably beat its expectations thanks partly to its Otway Basin wells. Outside this, Bell Potter is feeling very positive about Beach Energy's outlook. Especially given that its capital expenditure is trending lower, which it believes will be supportive of free cash flow growth. And with a positive view on Australian east coast gas and LNG markets, Bell Potter thinks now is a good time to buy this energy producer's shares. The Beach Energy share price ended the week at $1.27.

CSL Ltd (ASX: CSL)

Another note out of Bell Potter reveals that its analysts have initiated coverage on this biotechnology giant's shares with a buy rating and $345.00 price target. Bell Potter acknowledges that trading conditions could be relatively tough for the CSL Vifor and CSL Seqirus businesses in the near term. However, it expects this to be offset by strong growth from the key CSL Behring business. So much so, the broker believes that the company is positioned to deliver double-digit earnings growth in the coming years. So, with its shares looking undervalued compared to historical multiples, it feels that now could be a great time to snap them up. The CSL share price was fetching $293.69 at Friday's close.

WiseTech Global Ltd (ASX: WTC)

Analysts at Goldman Sachs have upgraded this logistics solutions company's shares to a buy rating with a $138.00 price target. According to the note, the broker believes that the significant sell off this week has created a compelling opportunity to buy one of Australia's best global growth stories. This is particularly the case given that Goldman believes there is about to be an acceleration in WiseTech Global's organic earnings growth. Its analysts think that the adoption of CargoWise is a matter of when, not if, for all large freight forwarders, providing material scope for new customer acquisition in the near future. The WiseTech Global share price ended last week at $112.00.